397 files changed, 36615 insertions, 27931 deletions

diff --git a/crates/expect/Cargo.toml b/crates/expect/Cargo.toml
new file mode 100644
index 000000000..77775630d
--- /dev/null
+++ b/crates/expect/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "expect"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
+
+[dependencies]
+once_cell = "1"
+difference = "2"
+stdx = { path = "../stdx" }
diff --git a/crates/expect/src/lib.rs b/crates/expect/src/lib.rs
new file mode 100644
index 000000000..21a458d47
--- /dev/null
+++ b/crates/expect/src/lib.rs
@@ -0,0 +1,356 @@
+//! Snapshot testing library, see
+//! https://github.com/rust-analyzer/rust-analyzer/pull/5101
+use std::{
+    collections::HashMap,
+    env, fmt, fs, mem,
+    ops::Range,
+    panic,
+    path::{Path, PathBuf},
+    sync::Mutex,
+};
+
+use difference::Changeset;
+use once_cell::sync::Lazy;
+use stdx::{lines_with_ends, trim_indent};
+
+const HELP: &str = "
+You can update all `expect![[]]` tests by running:
+
+    env UPDATE_EXPECT=1 cargo test
+
+To update a single test, place the cursor on `expect` token and use `run` feature of rust-analyzer.
+";
+
+fn update_expect() -> bool {
+    env::var("UPDATE_EXPECT").is_ok()
+}
+
+/// expect![[r#"inline snapshot"#]]
+#[macro_export]
+macro_rules! expect {
+    [[$data:literal]] => {$crate::Expect {
+        position: $crate::Position {
+            file: file!(),
+            line: line!(),
+            column: column!(),
+        },
+        data: $data,
+    }};
+    [[]] => { $crate::expect![[""]] };
+}
+
+/// expect_file!["/crates/foo/test_data/bar.html"]
+#[macro_export]
+macro_rules! expect_file {
+    [$path:expr] => {$crate::ExpectFile {
+        path: std::path::PathBuf::from($path)
+    }};
+}
+
+#[derive(Debug)]
+pub struct Expect {
+    pub position: Position,
+    pub data: &'static str,
+}
+
+#[derive(Debug)]
+pub struct ExpectFile {
+    pub path: PathBuf,
+}
+
+#[derive(Debug)]
+pub struct Position {
+    pub file: &'static str,
+    pub line: u32,
+    pub column: u32,
+}
+
+impl fmt::Display for Position {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}:{}:{}", self.file, self.line, self.column)
+    }
+}
+
+impl Expect {
+    pub fn assert_eq(&self, actual: &str) {
+        let trimmed = self.trimmed();
+        if &trimmed == actual {
+            return;
+        }
+        Runtime::fail_expect(self, &trimmed, actual);
+    }
+    pub fn assert_debug_eq(&self, actual: &impl fmt::Debug) {
+        let actual = format!("{:#?}\n", actual);
+        self.assert_eq(&actual)
+    }
+
+    fn trimmed(&self) -> String {
+        if !self.data.contains('\n') {
+            return self.data.to_string();
+        }
+        trim_indent(self.data)
+    }
+
+    fn locate(&self, file: &str) -> Location {
+        let mut target_line = None;
+        let mut line_start = 0;
+        for (i, line) in lines_with_ends(file).enumerate() {
+            if i == self.position.line as usize - 1 {
+                let pat = "expect![[";
+                let offset = line.find(pat).unwrap();
+                let literal_start = line_start + offset + pat.len();
+                let indent = line.chars().take_while(|&it| it == ' ').count();
+                target_line = Some((literal_start, indent));
+                break;
+            }
+            line_start += line.len();
+        }
+        let (literal_start, line_indent) = target_line.unwrap();
+        let literal_length =
+            file[literal_start..].find("]]").expect("Couldn't find matching `]]` for `expect![[`.");
+        let literal_range = literal_start..literal_start + literal_length;
+        Location { line_indent, literal_range }
+    }
+}
+
+impl ExpectFile {
+    pub fn assert_eq(&self, actual: &str) {
+        let expected = self.read();
+        if actual == expected {
+            return;
+        }
+        Runtime::fail_file(self, &expected, actual);
+    }
+    pub fn assert_debug_eq(&self, actual: &impl fmt::Debug) {
+        let actual = format!("{:#?}\n", actual);
+        self.assert_eq(&actual)
+    }
+    fn read(&self) -> String {
+        fs::read_to_string(self.abs_path()).unwrap_or_default().replace("\r\n", "\n")
+    }
+    fn write(&self, contents: &str) {
+        fs::write(self.abs_path(), contents).unwrap()
+    }
+    fn abs_path(&self) -> PathBuf {
+        WORKSPACE_ROOT.join(&self.path)
+    }
+}
+
+#[derive(Default)]
+struct Runtime {
+    help_printed: bool,
+    per_file: HashMap<&'static str, FileRuntime>,
+}
+static RT: Lazy<Mutex<Runtime>> = Lazy::new(Default::default);
+
+impl Runtime {
+    fn fail_expect(expect: &Expect, expected: &str, actual: &str) {
+        let mut rt = RT.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if update_expect() {
+            println!("\x1b[1m\x1b[92mupdating\x1b[0m: {}", expect.position);
+            rt.per_file
+                .entry(expect.position.file)
+                .or_insert_with(|| FileRuntime::new(expect))
+                .update(expect, actual);
+            return;
+        }
+        rt.panic(expect.position.to_string(), expected, actual);
+    }
+
+    fn fail_file(expect: &ExpectFile, expected: &str, actual: &str) {
+        let mut rt = RT.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if update_expect() {
+            println!("\x1b[1m\x1b[92mupdating\x1b[0m: {}", expect.path.display());
+            expect.write(actual);
+            return;
+        }
+        rt.panic(expect.path.display().to_string(), expected, actual);
+    }
+
+    fn panic(&mut self, position: String, expected: &str, actual: &str) {
+        let print_help = !mem::replace(&mut self.help_printed, true);
+        let help = if print_help { HELP } else { "" };
+
+        let diff = Changeset::new(actual, expected, "\n");
+
+        println!(
+            "\n
+\x1b[1m\x1b[91merror\x1b[97m: expect test failed\x1b[0m
+   \x1b[1m\x1b[34m-->\x1b[0m {}
+{}
+\x1b[1mExpect\x1b[0m:
+----
+{}
+----
+
+\x1b[1mActual\x1b[0m:
+----
+{}
+----
+
+\x1b[1mDiff\x1b[0m:
+----
+{}
+----
+",
+            position, help, expected, actual, diff
+        );
+        // Use resume_unwind instead of panic!() to prevent a backtrace, which is unnecessary noise.
+        panic::resume_unwind(Box::new(()));
+    }
+}
+
+struct FileRuntime {
+    path: PathBuf,
+    original_text: String,
+    patchwork: Patchwork,
+}
+
+impl FileRuntime {
+    fn new(expect: &Expect) -> FileRuntime {
+        let path = WORKSPACE_ROOT.join(expect.position.file);
+        let original_text = fs::read_to_string(&path).unwrap();
+        let patchwork = Patchwork::new(original_text.clone());
+        FileRuntime { path, original_text, patchwork }
+    }
+    fn update(&mut self, expect: &Expect, actual: &str) {
+        let loc = expect.locate(&self.original_text);
+        let patch = format_patch(loc.line_indent.clone(), actual);
+        self.patchwork.patch(loc.literal_range, &patch);
+        fs::write(&self.path, &self.patchwork.text).unwrap()
+    }
+}
+
+#[derive(Debug)]
+struct Location {
+    line_indent: usize,
+    literal_range: Range<usize>,
+}
+
+#[derive(Debug)]
+struct Patchwork {
+    text: String,
+    indels: Vec<(Range<usize>, usize)>,
+}
+
+impl Patchwork {
+    fn new(text: String) -> Patchwork {
+        Patchwork { text, indels: Vec::new() }
+    }
+    fn patch(&mut self, mut range: Range<usize>, patch: &str) {
+        self.indels.push((range.clone(), patch.len()));
+        self.indels.sort_by_key(|(delete, _insert)| delete.start);
+
+        let (delete, insert) = self
+            .indels
+            .iter()
+            .take_while(|(delete, _)| delete.start < range.start)
+            .map(|(delete, insert)| (delete.end - delete.start, insert))
+            .fold((0usize, 0usize), |(x1, y1), (x2, y2)| (x1 + x2, y1 + y2));
+
+        for pos in &mut [&mut range.start, &mut range.end] {
+            **pos -= delete;
+            **pos += insert;
+        }
+
+        self.text.replace_range(range, &patch);
+    }
+}
+
+fn format_patch(line_indent: usize, patch: &str) -> String {
+    let mut max_hashes = 0;
+    let mut cur_hashes = 0;
+    for byte in patch.bytes() {
+        if byte != b'#' {
+            cur_hashes = 0;
+            continue;
+        }
+        cur_hashes += 1;
+        max_hashes = max_hashes.max(cur_hashes);
+    }
+    let hashes = &"#".repeat(max_hashes + 1);
+    let indent = &" ".repeat(line_indent);
+    let is_multiline = patch.contains('\n');
+
+    let mut buf = String::new();
+    buf.push('r');
+    buf.push_str(hashes);
+    buf.push('"');
+    if is_multiline {
+        buf.push('\n');
+    }
+    let mut final_newline = false;
+    for line in lines_with_ends(patch) {
+        if is_multiline && !line.trim().is_empty() {
+            buf.push_str(indent);
+            buf.push_str("    ");
+        }
+        buf.push_str(line);
+        final_newline = line.ends_with('\n');
+    }
+    if final_newline {
+        buf.push_str(indent);
+    }
+    buf.push('"');
+    buf.push_str(hashes);
+    buf
+}
+
+static WORKSPACE_ROOT: Lazy<PathBuf> = Lazy::new(|| {
+    let my_manifest =
+        env::var("CARGO_MANIFEST_DIR").unwrap_or_else(|_| env!("CARGO_MANIFEST_DIR").to_owned());
+    // Heuristic, see https://github.com/rust-lang/cargo/issues/3946
+    Path::new(&my_manifest)
+        .ancestors()
+        .filter(|it| it.join("Cargo.toml").exists())
+        .last()
+        .unwrap()
+        .to_path_buf()
+});
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_format_patch() {
+        let patch = format_patch(0, "hello\nworld\n");
+        expect![[r##"
+            r#"
+                hello
+                world
+            "#"##]]
+        .assert_eq(&patch);
+
+        let patch = format_patch(4, "single line");
+        expect![[r##"r#"single line"#"##]].assert_eq(&patch);
+    }
+
+    #[test]
+    fn test_patchwork() {
+        let mut patchwork = Patchwork::new("one two three".to_string());
+        patchwork.patch(4..7, "zwei");
+        patchwork.patch(0..3, "один");
+        patchwork.patch(8..13, "3");
+        expect![[r#"
+            Patchwork {
+                text: "один zwei 3",
+                indels: [
+                    (
+                        0..3,
+                        8,
+                    ),
+                    (
+                        4..7,
+                        4,
+                    ),
+                    (
+                        8..13,
+                        1,
+                    ),
+                ],
+            }
+        "#]]
+        .assert_debug_eq(&patchwork);
+    }
+}
diff --git a/crates/ra_flycheck/Cargo.toml b/crates/flycheck/Cargo.toml
index 1aa39bade..bea485694 100644
--- a/crates/ra_flycheck/Cargo.toml
+++ b/crates/flycheck/Cargo.toml
@@ -1,8 +1,9 @@
 [package]
 edition = "2018"
-name = "ra_flycheck"
+name = "flycheck"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/flycheck/src/lib.rs b/crates/flycheck/src/lib.rs
new file mode 100644
index 000000000..6804d9bda
--- /dev/null
+++ b/crates/flycheck/src/lib.rs
@@ -0,0 +1,317 @@
+//! cargo_check provides the functionality needed to run `cargo check` or
+//! another compatible command (f.x. clippy) in a background thread and provide
+//! LSP diagnostics based on the output of the command.
+
+use std::{
+    fmt,
+    io::{self, BufReader},
+    ops,
+    path::PathBuf,
+    process::{self, Command, Stdio},
+    time::Duration,
+};
+
+use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
+
+pub use cargo_metadata::diagnostic::{
+    Applicability, Diagnostic, DiagnosticCode, DiagnosticLevel, DiagnosticSpan,
+    DiagnosticSpanMacroExpansion,
+};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum FlycheckConfig {
+    CargoCommand {
+        command: String,
+        all_targets: bool,
+        all_features: bool,
+        features: Vec<String>,
+        extra_args: Vec<String>,
+    },
+    CustomCommand {
+        command: String,
+        args: Vec<String>,
+    },
+}
+
+impl fmt::Display for FlycheckConfig {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            FlycheckConfig::CargoCommand { command, .. } => write!(f, "cargo {}", command),
+            FlycheckConfig::CustomCommand { command, args } => {
+                write!(f, "{} {}", command, args.join(" "))
+            }
+        }
+    }
+}
+
+/// Flycheck wraps the shared state and communication machinery used for
+/// running `cargo check` (or other compatible command) and providing
+/// diagnostics based on the output.
+/// The spawned thread is shut down when this struct is dropped.
+#[derive(Debug)]
+pub struct FlycheckHandle {
+    // XXX: drop order is significant
+    sender: Sender<Restart>,
+    thread: jod_thread::JoinHandle,
+}
+
+impl FlycheckHandle {
+    pub fn spawn(
+        sender: Box<dyn Fn(Message) + Send>,
+        config: FlycheckConfig,
+        workspace_root: PathBuf,
+    ) -> FlycheckHandle {
+        let actor = FlycheckActor::new(sender, config, workspace_root);
+        let (sender, receiver) = unbounded::<Restart>();
+        let thread = jod_thread::spawn(move || actor.run(receiver));
+        FlycheckHandle { sender, thread }
+    }
+
+    /// Schedule a re-start of the cargo check worker.
+    pub fn update(&self) {
+        self.sender.send(Restart).unwrap();
+    }
+}
+
+#[derive(Debug)]
+pub enum Message {
+    /// Request adding a diagnostic with fixes included to a file
+    AddDiagnostic { workspace_root: PathBuf, diagnostic: Diagnostic },
+
+    /// Request check progress notification to client
+    Progress(Progress),
+}
+
+#[derive(Debug)]
+pub enum Progress {
+    DidStart,
+    DidCheckCrate(String),
+    DidFinish(io::Result<()>),
+    DidCancel,
+}
+
+struct Restart;
+
+struct FlycheckActor {
+    sender: Box<dyn Fn(Message) + Send>,
+    config: FlycheckConfig,
+    workspace_root: PathBuf,
+    /// WatchThread exists to wrap around the communication needed to be able to
+    /// run `cargo check` without blocking. Currently the Rust standard library
+    /// doesn't provide a way to read sub-process output without blocking, so we
+    /// have to wrap sub-processes output handling in a thread and pass messages
+    /// back over a channel.
+    cargo_handle: Option<CargoHandle>,
+}
+
+enum Event {
+    Restart(Restart),
+    CheckEvent(Option<cargo_metadata::Message>),
+}
+
+impl FlycheckActor {
+    fn new(
+        sender: Box<dyn Fn(Message) + Send>,
+        config: FlycheckConfig,
+        workspace_root: PathBuf,
+    ) -> FlycheckActor {
+        FlycheckActor { sender, config, workspace_root, cargo_handle: None }
+    }
+    fn next_event(&self, inbox: &Receiver<Restart>) -> Option<Event> {
+        let check_chan = self.cargo_handle.as_ref().map(|cargo| &cargo.receiver);
+        select! {
+            recv(inbox) -> msg => msg.ok().map(Event::Restart),
+            recv(check_chan.unwrap_or(&never())) -> msg => Some(Event::CheckEvent(msg.ok())),
+        }
+    }
+    fn run(mut self, inbox: Receiver<Restart>) {
+        while let Some(event) = self.next_event(&inbox) {
+            match event {
+                Event::Restart(Restart) => {
+                    while let Ok(Restart) = inbox.recv_timeout(Duration::from_millis(50)) {}
+
+                    self.cancel_check_process();
+
+                    let mut command = self.check_command();
+                    log::info!("restart flycheck {:?}", command);
+                    command.stdout(Stdio::piped()).stderr(Stdio::null()).stdin(Stdio::null());
+                    if let Ok(child) = command.spawn().map(JodChild) {
+                        self.cargo_handle = Some(CargoHandle::spawn(child));
+                        self.send(Message::Progress(Progress::DidStart));
+                    }
+                }
+                Event::CheckEvent(None) => {
+                    // Watcher finished, replace it with a never channel to
+                    // avoid busy-waiting.
+                    let cargo_handle = self.cargo_handle.take().unwrap();
+                    let res = cargo_handle.join();
+                    self.send(Message::Progress(Progress::DidFinish(res)));
+                }
+                Event::CheckEvent(Some(message)) => match message {
+                    cargo_metadata::Message::CompilerArtifact(msg) => {
+                        self.send(Message::Progress(Progress::DidCheckCrate(msg.target.name)));
+                    }
+
+                    cargo_metadata::Message::CompilerMessage(msg) => {
+                        self.send(Message::AddDiagnostic {
+                            workspace_root: self.workspace_root.clone(),
+                            diagnostic: msg.message,
+                        });
+                    }
+
+                    cargo_metadata::Message::BuildScriptExecuted(_)
+                    | cargo_metadata::Message::BuildFinished(_)
+                    | cargo_metadata::Message::TextLine(_)
+                    | cargo_metadata::Message::Unknown => {}
+                },
+            }
+        }
+        // If we rerun the thread, we need to discard the previous check results first
+        self.cancel_check_process();
+    }
+    fn cancel_check_process(&mut self) {
+        if self.cargo_handle.take().is_some() {
+            self.send(Message::Progress(Progress::DidCancel));
+        }
+    }
+    fn check_command(&self) -> Command {
+        let mut cmd = match &self.config {
+            FlycheckConfig::CargoCommand {
+                command,
+                all_targets,
+                all_features,
+                extra_args,
+                features,
+            } => {
+                let mut cmd = Command::new(ra_toolchain::cargo());
+                cmd.arg(command);
+                cmd.args(&["--workspace", "--message-format=json", "--manifest-path"])
+                    .arg(self.workspace_root.join("Cargo.toml"));
+                if *all_targets {
+                    cmd.arg("--all-targets");
+                }
+                if *all_features {
+                    cmd.arg("--all-features");
+                } else if !features.is_empty() {
+                    cmd.arg("--features");
+                    cmd.arg(features.join(" "));
+                }
+                cmd.args(extra_args);
+                cmd
+            }
+            FlycheckConfig::CustomCommand { command, args } => {
+                let mut cmd = Command::new(command);
+                cmd.args(args);
+                cmd
+            }
+        };
+        cmd.current_dir(&self.workspace_root);
+        cmd
+    }
+
+    fn send(&self, check_task: Message) {
+        (self.sender)(check_task)
+    }
+}
+
+struct CargoHandle {
+    child: JodChild,
+    #[allow(unused)]
+    thread: jod_thread::JoinHandle<io::Result<bool>>,
+    receiver: Receiver<cargo_metadata::Message>,
+}
+
+impl CargoHandle {
+    fn spawn(mut child: JodChild) -> CargoHandle {
+        let child_stdout = child.stdout.take().unwrap();
+        let (sender, receiver) = unbounded();
+        let actor = CargoActor::new(child_stdout, sender);
+        let thread = jod_thread::spawn(move || actor.run());
+        CargoHandle { child, thread, receiver }
+    }
+    fn join(mut self) -> io::Result<()> {
+        // It is okay to ignore the result, as it only errors if the process is already dead
+        let _ = self.child.kill();
+        let exit_status = self.child.wait()?;
+        let read_at_least_one_message = self.thread.join()?;
+        if !exit_status.success() && !read_at_least_one_message {
+            // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment:
+            // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298
+            return Err(io::Error::new(
+                io::ErrorKind::Other,
+                format!(
+                    "Cargo watcher failed,the command produced no valid metadata (exit code: {:?})",
+                    exit_status
+                ),
+            ));
+        }
+        Ok(())
+    }
+}
+
+struct CargoActor {
+    child_stdout: process::ChildStdout,
+    sender: Sender<cargo_metadata::Message>,
+}
+
+impl CargoActor {
+    fn new(
+        child_stdout: process::ChildStdout,
+        sender: Sender<cargo_metadata::Message>,
+    ) -> CargoActor {
+        CargoActor { child_stdout, sender }
+    }
+    fn run(self) -> io::Result<bool> {
+        // We manually read a line at a time, instead of using serde's
+        // stream deserializers, because the deserializer cannot recover
+        // from an error, resulting in it getting stuck, because we try to
+        // be resilient against failures.
+        //
+        // Because cargo only outputs one JSON object per line, we can
+        // simply skip a line if it doesn't parse, which just ignores any
+        // erroneus output.
+        let stdout = BufReader::new(self.child_stdout);
+        let mut read_at_least_one_message = false;
+        for message in cargo_metadata::Message::parse_stream(stdout) {
+            let message = match message {
+                Ok(message) => message,
+                Err(err) => {
+                    log::error!("Invalid json from cargo check, ignoring ({})", err);
+                    continue;
+                }
+            };
+
+            read_at_least_one_message = true;
+
+            // Skip certain kinds of messages to only spend time on what's useful
+            match &message {
+                cargo_metadata::Message::CompilerArtifact(artifact) if artifact.fresh => (),
+                cargo_metadata::Message::BuildScriptExecuted(_)
+                | cargo_metadata::Message::Unknown => (),
+                _ => self.sender.send(message).unwrap(),
+            }
+        }
+        Ok(read_at_least_one_message)
+    }
+}
+
+struct JodChild(process::Child);
+
+impl ops::Deref for JodChild {
+    type Target = process::Child;
+    fn deref(&self) -> &process::Child {
+        &self.0
+    }
+}
+
+impl ops::DerefMut for JodChild {
+    fn deref_mut(&mut self) -> &mut process::Child {
+        &mut self.0
+    }
+}
+
+impl Drop for JodChild {
+    fn drop(&mut self) {
+        let _ = self.0.kill();
+    }
+}
diff --git a/crates/paths/Cargo.toml b/crates/paths/Cargo.toml
new file mode 100644
index 000000000..cbe2c26e2
--- /dev/null
+++ b/crates/paths/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "paths"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
diff --git a/crates/paths/src/lib.rs b/crates/paths/src/lib.rs
new file mode 100644
index 000000000..1b259682d
--- /dev/null
+++ b/crates/paths/src/lib.rs
@@ -0,0 +1,217 @@
+//! Thin wrappers around `std::path`, distinguishing between absolute and
+//! relative paths.
+use std::{
+    convert::{TryFrom, TryInto},
+    ops,
+    path::{Component, Path, PathBuf},
+};
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct AbsPathBuf(PathBuf);
+
+impl From<AbsPathBuf> for PathBuf {
+    fn from(AbsPathBuf(path_buf): AbsPathBuf) -> PathBuf {
+        path_buf
+    }
+}
+
+impl ops::Deref for AbsPathBuf {
+    type Target = AbsPath;
+    fn deref(&self) -> &AbsPath {
+        self.as_path()
+    }
+}
+
+impl AsRef<Path> for AbsPathBuf {
+    fn as_ref(&self) -> &Path {
+        self.0.as_path()
+    }
+}
+
+impl AsRef<AbsPath> for AbsPathBuf {
+    fn as_ref(&self) -> &AbsPath {
+        self.as_path()
+    }
+}
+
+impl TryFrom<PathBuf> for AbsPathBuf {
+    type Error = PathBuf;
+    fn try_from(path_buf: PathBuf) -> Result<AbsPathBuf, PathBuf> {
+        if !path_buf.is_absolute() {
+            return Err(path_buf);
+        }
+        Ok(AbsPathBuf(path_buf))
+    }
+}
+
+impl TryFrom<&str> for AbsPathBuf {
+    type Error = PathBuf;
+    fn try_from(path: &str) -> Result<AbsPathBuf, PathBuf> {
+        AbsPathBuf::try_from(PathBuf::from(path))
+    }
+}
+
+impl PartialEq<AbsPath> for AbsPathBuf {
+    fn eq(&self, other: &AbsPath) -> bool {
+        self.as_path() == other
+    }
+}
+
+impl AbsPathBuf {
+    pub fn assert(path: PathBuf) -> AbsPathBuf {
+        AbsPathBuf::try_from(path)
+            .unwrap_or_else(|path| panic!("expected absolute path, got {}", path.display()))
+    }
+    pub fn as_path(&self) -> &AbsPath {
+        AbsPath::assert(self.0.as_path())
+    }
+    pub fn pop(&mut self) -> bool {
+        self.0.pop()
+    }
+}
+
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+#[repr(transparent)]
+pub struct AbsPath(Path);
+
+impl ops::Deref for AbsPath {
+    type Target = Path;
+    fn deref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl AsRef<Path> for AbsPath {
+    fn as_ref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl<'a> TryFrom<&'a Path> for &'a AbsPath {
+    type Error = &'a Path;
+    fn try_from(path: &'a Path) -> Result<&'a AbsPath, &'a Path> {
+        if !path.is_absolute() {
+            return Err(path);
+        }
+        Ok(AbsPath::assert(path))
+    }
+}
+
+impl AbsPath {
+    pub fn assert(path: &Path) -> &AbsPath {
+        assert!(path.is_absolute());
+        unsafe { &*(path as *const Path as *const AbsPath) }
+    }
+
+    pub fn parent(&self) -> Option<&AbsPath> {
+        self.0.parent().map(AbsPath::assert)
+    }
+    pub fn join(&self, path: impl AsRef<Path>) -> AbsPathBuf {
+        self.as_ref().join(path).try_into().unwrap()
+    }
+    pub fn normalize(&self) -> AbsPathBuf {
+        AbsPathBuf(normalize_path(&self.0))
+    }
+    pub fn to_path_buf(&self) -> AbsPathBuf {
+        AbsPathBuf::try_from(self.0.to_path_buf()).unwrap()
+    }
+    pub fn strip_prefix(&self, base: &AbsPath) -> Option<&RelPath> {
+        self.0.strip_prefix(base).ok().map(RelPath::new_unchecked)
+    }
+}
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct RelPathBuf(PathBuf);
+
+impl From<RelPathBuf> for PathBuf {
+    fn from(RelPathBuf(path_buf): RelPathBuf) -> PathBuf {
+        path_buf
+    }
+}
+
+impl ops::Deref for RelPathBuf {
+    type Target = RelPath;
+    fn deref(&self) -> &RelPath {
+        self.as_path()
+    }
+}
+
+impl AsRef<Path> for RelPathBuf {
+    fn as_ref(&self) -> &Path {
+        self.0.as_path()
+    }
+}
+
+impl TryFrom<PathBuf> for RelPathBuf {
+    type Error = PathBuf;
+    fn try_from(path_buf: PathBuf) -> Result<RelPathBuf, PathBuf> {
+        if !path_buf.is_relative() {
+            return Err(path_buf);
+        }
+        Ok(RelPathBuf(path_buf))
+    }
+}
+
+impl TryFrom<&str> for RelPathBuf {
+    type Error = PathBuf;
+    fn try_from(path: &str) -> Result<RelPathBuf, PathBuf> {
+        RelPathBuf::try_from(PathBuf::from(path))
+    }
+}
+
+impl RelPathBuf {
+    pub fn as_path(&self) -> &RelPath {
+        RelPath::new_unchecked(self.0.as_path())
+    }
+}
+
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+#[repr(transparent)]
+pub struct RelPath(Path);
+
+impl ops::Deref for RelPath {
+    type Target = Path;
+    fn deref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl AsRef<Path> for RelPath {
+    fn as_ref(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl RelPath {
+    pub fn new_unchecked(path: &Path) -> &RelPath {
+        unsafe { &*(path as *const Path as *const RelPath) }
+    }
+}
+
+// https://github.com/rust-lang/cargo/blob/79c769c3d7b4c2cf6a93781575b7f592ef974255/src/cargo/util/paths.rs#L60-L85
+fn normalize_path(path: &Path) -> PathBuf {
+    let mut components = path.components().peekable();
+    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
+        components.next();
+        PathBuf::from(c.as_os_str())
+    } else {
+        PathBuf::new()
+    };
+
+    for component in components {
+        match component {
+            Component::Prefix(..) => unreachable!(),
+            Component::RootDir => {
+                ret.push(component.as_os_str());
+            }
+            Component::CurDir => {}
+            Component::ParentDir => {
+                ret.pop();
+            }
+            Component::Normal(c) => {
+                ret.push(c);
+            }
+        }
+    }
+    ret
+}
diff --git a/crates/ra_arena/Cargo.toml b/crates/ra_arena/Cargo.toml
index d287dbb73..66c3738f4 100644
--- a/crates/ra_arena/Cargo.toml
+++ b/crates/ra_arena/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_arena"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_arena/src/lib.rs b/crates/ra_arena/src/lib.rs
index 441fbb3cb..3169aa5b8 100644
--- a/crates/ra_arena/src/lib.rs
+++ b/crates/ra_arena/src/lib.rs
@@ -116,6 +116,9 @@ impl<T> Arena<T> {
     ) -> impl Iterator<Item = (Idx<T>, &T)> + ExactSizeIterator + DoubleEndedIterator {
         self.data.iter().enumerate().map(|(idx, value)| (Idx::from_raw(RawId(idx as u32)), value))
     }
+    pub fn shrink_to_fit(&mut self) {
+        self.data.shrink_to_fit();
+    }
 }
 
 impl<T> Default for Arena<T> {
diff --git a/crates/ra_assists/Cargo.toml b/crates/ra_assists/Cargo.toml
index 3bcf58ba4..bd2905f08 100644
--- a/crates/ra_assists/Cargo.toml
+++ b/crates/ra_assists/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_assists"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_assists/src/assist_config.rs b/crates/ra_assists/src/assist_config.rs
index c0a0226fb..cda2abfb9 100644
--- a/crates/ra_assists/src/assist_config.rs
+++ b/crates/ra_assists/src/assist_config.rs
@@ -4,9 +4,12 @@
 //! module, and we use to statically check that we only produce snippet
 //! assists if we are allowed to.
 
+use crate::AssistKind;
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct AssistConfig {
     pub snippet_cap: Option<SnippetCap>,
+    pub allowed: Option<Vec<AssistKind>>,
 }
 
 impl AssistConfig {
@@ -22,6 +25,6 @@ pub struct SnippetCap {
 
 impl Default for AssistConfig {
     fn default() -> Self {
-        AssistConfig { snippet_cap: Some(SnippetCap { _private: () }) }
+        AssistConfig { snippet_cap: Some(SnippetCap { _private: () }), allowed: None }
     }
 }
diff --git a/crates/ra_assists/src/assist_context.rs b/crates/ra_assists/src/assist_context.rs
index 5b1a4680b..3407df856 100644
--- a/crates/ra_assists/src/assist_context.rs
+++ b/crates/ra_assists/src/assist_context.rs
@@ -1,5 +1,7 @@
 //! See `AssistContext`
 
+use std::mem;
+
 use algo::find_covering_element;
 use hir::Semantics;
 use ra_db::{FileId, FileRange};
@@ -17,7 +19,7 @@ use ra_text_edit::TextEditBuilder;
 
 use crate::{
     assist_config::{AssistConfig, SnippetCap},
-    Assist, AssistId, GroupLabel, ResolvedAssist,
+    Assist, AssistId, AssistKind, GroupLabel, ResolvedAssist,
 };
 
 /// `AssistContext` allows to apply an assist or check if it could be applied.
@@ -53,7 +55,6 @@ use crate::{
 pub(crate) struct AssistContext<'a> {
     pub(crate) config: &'a AssistConfig,
     pub(crate) sema: Semantics<'a, RootDatabase>,
-    pub(crate) db: &'a RootDatabase,
     pub(crate) frange: FileRange,
     source_file: SourceFile,
 }
@@ -65,8 +66,11 @@ impl<'a> AssistContext<'a> {
         frange: FileRange,
     ) -> AssistContext<'a> {
         let source_file = sema.parse(frange.file_id);
-        let db = sema.db;
-        AssistContext { config, sema, db, frange, source_file }
+        AssistContext { config, sema, frange, source_file }
+    }
+
+    pub(crate) fn db(&self) -> &RootDatabase {
+        self.sema.db
     }
 
     // NB, this ignores active selection.
@@ -99,14 +103,26 @@ pub(crate) struct Assists {
     resolve: bool,
     file: FileId,
     buf: Vec<(Assist, Option<SourceChange>)>,
+    allowed: Option<Vec<AssistKind>>,
 }
 
 impl Assists {
     pub(crate) fn new_resolved(ctx: &AssistContext) -> Assists {
-        Assists { resolve: true, file: ctx.frange.file_id, buf: Vec::new() }
+        Assists {
+            resolve: true,
+            file: ctx.frange.file_id,
+            buf: Vec::new(),
+            allowed: ctx.config.allowed.clone(),
+        }
     }
+
     pub(crate) fn new_unresolved(ctx: &AssistContext) -> Assists {
-        Assists { resolve: false, file: ctx.frange.file_id, buf: Vec::new() }
+        Assists {
+            resolve: false,
+            file: ctx.frange.file_id,
+            buf: Vec::new(),
+            allowed: ctx.config.allowed.clone(),
+        }
     }
 
     pub(crate) fn finish_unresolved(self) -> Vec<Assist> {
@@ -135,9 +151,13 @@ impl Assists {
         target: TextRange,
         f: impl FnOnce(&mut AssistBuilder),
     ) -> Option<()> {
+        if !self.is_allowed(&id) {
+            return None;
+        }
         let label = Assist::new(id, label.into(), None, target);
         self.add_impl(label, f)
     }
+
     pub(crate) fn add_group(
         &mut self,
         group: &GroupLabel,
@@ -146,9 +166,14 @@ impl Assists {
         target: TextRange,
         f: impl FnOnce(&mut AssistBuilder),
     ) -> Option<()> {
+        if !self.is_allowed(&id) {
+            return None;
+        }
+
         let label = Assist::new(id, label.into(), Some(group.clone()), target);
         self.add_impl(label, f)
     }
+
     fn add_impl(&mut self, label: Assist, f: impl FnOnce(&mut AssistBuilder)) -> Option<()> {
         let source_change = if self.resolve {
             let mut builder = AssistBuilder::new(self.file);
@@ -166,17 +191,43 @@ impl Assists {
         self.buf.sort_by_key(|(label, _edit)| label.target.len());
         self.buf
     }
+
+    fn is_allowed(&self, id: &AssistId) -> bool {
+        match &self.allowed {
+            Some(allowed) => allowed.iter().any(|kind| kind.contains(id.1)),
+            None => true,
+        }
+    }
 }
 
 pub(crate) struct AssistBuilder {
     edit: TextEditBuilder,
-    file: FileId,
+    file_id: FileId,
     is_snippet: bool,
+    change: SourceChange,
 }
 
 impl AssistBuilder {
-    pub(crate) fn new(file: FileId) -> AssistBuilder {
-        AssistBuilder { edit: TextEditBuilder::default(), file, is_snippet: false }
+    pub(crate) fn new(file_id: FileId) -> AssistBuilder {
+        AssistBuilder {
+            edit: TextEditBuilder::default(),
+            file_id,
+            is_snippet: false,
+            change: SourceChange::default(),
+        }
+    }
+
+    pub(crate) fn edit_file(&mut self, file_id: FileId) {
+        self.file_id = file_id;
+    }
+
+    fn commit(&mut self) {
+        let edit = mem::take(&mut self.edit).finish();
+        if !edit.is_empty() {
+            let new_edit = SourceFileEdit { file_id: self.file_id, edit };
+            assert!(!self.change.source_file_edits.iter().any(|it| it.file_id == new_edit.file_id));
+            self.change.source_file_edits.push(new_edit);
+        }
     }
 
     /// Remove specified `range` of text.
@@ -231,12 +282,7 @@ impl AssistBuilder {
     pub(crate) fn rewrite(&mut self, rewriter: SyntaxRewriter) {
         let node = rewriter.rewrite_root().unwrap();
         let new = rewriter.rewrite(&node);
-        algo::diff(&node, &new).into_text_edit(&mut self.edit)
-    }
-
-    // FIXME: better API
-    pub(crate) fn set_file(&mut self, assist_file: FileId) {
-        self.file = assist_file;
+        algo::diff(&node, &new).into_text_edit(&mut self.edit);
     }
 
     // FIXME: kill this API
@@ -245,13 +291,12 @@ impl AssistBuilder {
         &mut self.edit
     }
 
-    fn finish(self) -> SourceChange {
-        let edit = self.edit.finish();
-        let source_file_edit = SourceFileEdit { file_id: self.file, edit };
-        let mut res: SourceChange = source_file_edit.into();
+    fn finish(mut self) -> SourceChange {
+        self.commit();
+        let mut change = mem::take(&mut self.change);
         if self.is_snippet {
-            res.is_snippet = true;
+            change.is_snippet = true;
         }
-        res
+        change
     }
 }
diff --git a/crates/ra_assists/src/ast_transform.rs b/crates/ra_assists/src/ast_transform.rs
index 3079a02a2..01adb834c 100644
--- a/crates/ra_assists/src/ast_transform.rs
+++ b/crates/ra_assists/src/ast_transform.rs
@@ -2,7 +2,6 @@
 use rustc_hash::FxHashMap;
 
 use hir::{HirDisplay, PathResolution, SemanticsScope};
-use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo::SyntaxRewriter,
     ast::{self, AstNode},
@@ -32,14 +31,14 @@ impl<'a> AstTransform<'a> for NullTransformer {
 }
 
 pub struct SubstituteTypeParams<'a> {
-    source_scope: &'a SemanticsScope<'a, RootDatabase>,
+    source_scope: &'a SemanticsScope<'a>,
     substs: FxHashMap<hir::TypeParam, ast::TypeRef>,
     previous: Box<dyn AstTransform<'a> + 'a>,
 }
 
 impl<'a> SubstituteTypeParams<'a> {
     pub fn for_trait_impl(
-        source_scope: &'a SemanticsScope<'a, RootDatabase>,
+        source_scope: &'a SemanticsScope<'a>,
         // FIXME: there's implicit invariant that `trait_` and  `source_scope` match...
         trait_: hir::Trait,
         impl_def: ast::ImplDef,
@@ -106,6 +105,7 @@ impl<'a> SubstituteTypeParams<'a> {
             _ => return None,
         };
         // FIXME: use `hir::Path::from_src` instead.
+        #[allow(deprecated)]
         let path = hir::Path::from_ast(path)?;
         let resolution = self.source_scope.resolve_hir_path(&path)?;
         match resolution {
@@ -125,16 +125,13 @@ impl<'a> AstTransform<'a> for SubstituteTypeParams<'a> {
 }
 
 pub struct QualifyPaths<'a> {
-    target_scope: &'a SemanticsScope<'a, RootDatabase>,
-    source_scope: &'a SemanticsScope<'a, RootDatabase>,
+    target_scope: &'a SemanticsScope<'a>,
+    source_scope: &'a SemanticsScope<'a>,
     previous: Box<dyn AstTransform<'a> + 'a>,
 }
 
 impl<'a> QualifyPaths<'a> {
-    pub fn new(
-        target_scope: &'a SemanticsScope<'a, RootDatabase>,
-        source_scope: &'a SemanticsScope<'a, RootDatabase>,
-    ) -> Self {
+    pub fn new(target_scope: &'a SemanticsScope<'a>, source_scope: &'a SemanticsScope<'a>) -> Self {
         Self { target_scope, source_scope, previous: Box::new(NullTransformer) }
     }
 
@@ -150,11 +147,12 @@ impl<'a> QualifyPaths<'a> {
             return None;
         }
         // FIXME: use `hir::Path::from_src` instead.
+        #[allow(deprecated)]
         let hir_path = hir::Path::from_ast(p.clone());
         let resolution = self.source_scope.resolve_hir_path(&hir_path?)?;
         match resolution {
             PathResolution::Def(def) => {
-                let found_path = from.find_use_path(self.source_scope.db, def)?;
+                let found_path = from.find_use_path(self.source_scope.db.upcast(), def)?;
                 let mut path = path_to_ast(found_path);
 
                 let type_args = p
diff --git a/crates/ra_assists/src/handlers/add_custom_impl.rs b/crates/ra_assists/src/handlers/add_custom_impl.rs
index fa70c8496..acb07e36a 100644
--- a/crates/ra_assists/src/handlers/add_custom_impl.rs
+++ b/crates/ra_assists/src/handlers/add_custom_impl.rs
@@ -8,7 +8,7 @@ use stdx::SepBy;
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: add_custom_impl
@@ -52,7 +52,7 @@ pub(crate) fn add_custom_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<
         format!("Add custom impl `{}` for `{}`", trait_token.text().as_str(), annotated_name);
 
     let target = attr.syntax().text_range();
-    acc.add(AssistId("add_custom_impl"), label, target, |builder| {
+    acc.add(AssistId("add_custom_impl", AssistKind::Refactor), label, target, |builder| {
         let new_attr_input = input
             .syntax()
             .descendants_with_tokens()
diff --git a/crates/ra_assists/src/handlers/add_explicit_type.rs b/crates/ra_assists/src/handlers/add_explicit_type.rs
index ab20c6649..39a5321d1 100644
--- a/crates/ra_assists/src/handlers/add_explicit_type.rs
+++ b/crates/ra_assists/src/handlers/add_explicit_type.rs
@@ -4,7 +4,7 @@ use ra_syntax::{
     TextRange,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: add_explicit_type
 //
@@ -57,9 +57,9 @@ pub(crate) fn add_explicit_type(acc: &mut Assists, ctx: &AssistContext) -> Optio
         return None;
     }
 
-    let inferred_type = ty.display_source_code(ctx.db, module.into()).ok()?;
+    let inferred_type = ty.display_source_code(ctx.db(), module.into()).ok()?;
     acc.add(
-        AssistId("add_explicit_type"),
+        AssistId("add_explicit_type", AssistKind::RefactorRewrite),
         format!("Insert explicit type `{}`", inferred_type),
         pat_range,
         |builder| match ascribed_ty {
@@ -195,7 +195,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test<|> = Test { t: 23, k: 33 };
+    let test<|> = Test { t: 23u8, k: 33 };
 }"#,
             r#"
 struct Test<K, T = u8> {
@@ -204,7 +204,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test: Test<i32> = Test { t: 23, k: 33 };
+    let test: Test<i32> = Test { t: 23u8, k: 33 };
 }"#,
         );
     }
diff --git a/crates/ra_assists/src/handlers/add_impl.rs b/crates/ra_assists/src/handlers/add_impl.rs
deleted file mode 100644
index eceba7d0a..000000000
--- a/crates/ra_assists/src/handlers/add_impl.rs
+++ /dev/null
@@ -1,98 +0,0 @@
-use ra_syntax::ast::{self, AstNode, NameOwner, TypeParamsOwner};
-use stdx::{format_to, SepBy};
-
-use crate::{AssistContext, AssistId, Assists};
-
-// Assist: add_impl
-//
-// Adds a new inherent impl for a type.
-//
-// ```
-// struct Ctx<T: Clone> {
-//     data: T,<|>
-// }
-// ```
-// ->
-// ```
-// struct Ctx<T: Clone> {
-//     data: T,
-// }
-//
-// impl<T: Clone> Ctx<T> {
-//     $0
-// }
-// ```
-pub(crate) fn add_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let nominal = ctx.find_node_at_offset::<ast::NominalDef>()?;
-    let name = nominal.name()?;
-    let target = nominal.syntax().text_range();
-    acc.add(AssistId("add_impl"), format!("Implement {}", name.text().as_str()), target, |edit| {
-        let type_params = nominal.type_param_list();
-        let start_offset = nominal.syntax().text_range().end();
-        let mut buf = String::new();
-        buf.push_str("\n\nimpl");
-        if let Some(type_params) = &type_params {
-            format_to!(buf, "{}", type_params.syntax());
-        }
-        buf.push_str(" ");
-        buf.push_str(name.text().as_str());
-        if let Some(type_params) = type_params {
-            let lifetime_params = type_params
-                .lifetime_params()
-                .filter_map(|it| it.lifetime_token())
-                .map(|it| it.text().clone());
-            let type_params =
-                type_params.type_params().filter_map(|it| it.name()).map(|it| it.text().clone());
-
-            let generic_params = lifetime_params.chain(type_params).sep_by(", ");
-            format_to!(buf, "<{}>", generic_params)
-        }
-        match ctx.config.snippet_cap {
-            Some(cap) => {
-                buf.push_str(" {\n    $0\n}");
-                edit.insert_snippet(cap, start_offset, buf);
-            }
-            None => {
-                buf.push_str(" {\n}");
-                edit.insert(start_offset, buf);
-            }
-        }
-    })
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::tests::{check_assist, check_assist_target};
-
-    use super::*;
-
-    #[test]
-    fn test_add_impl() {
-        check_assist(add_impl, "struct Foo {<|>}\n", "struct Foo {}\n\nimpl Foo {\n    $0\n}\n");
-        check_assist(
-            add_impl,
-            "struct Foo<T: Clone> {<|>}",
-            "struct Foo<T: Clone> {}\n\nimpl<T: Clone> Foo<T> {\n    $0\n}",
-        );
-        check_assist(
-            add_impl,
-            "struct Foo<'a, T: Foo<'a>> {<|>}",
-            "struct Foo<'a, T: Foo<'a>> {}\n\nimpl<'a, T: Foo<'a>> Foo<'a, T> {\n    $0\n}",
-        );
-    }
-
-    #[test]
-    fn add_impl_target() {
-        check_assist_target(
-            add_impl,
-            "
-struct SomeThingIrrelevant;
-/// Has a lifetime parameter
-struct Foo<'a, T: Foo<'a>> {<|>}
-struct EvenMoreIrrelevant;
-",
-            "/// Has a lifetime parameter
-struct Foo<'a, T: Foo<'a>> {}",
-        );
-    }
-}
diff --git a/crates/ra_assists/src/handlers/add_missing_impl_members.rs b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
index abacd4065..f185e61e5 100644
--- a/crates/ra_assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
@@ -12,7 +12,7 @@ use crate::{
     assist_context::{AssistContext, Assists},
     ast_transform::{self, AstTransform, QualifyPaths, SubstituteTypeParams},
     utils::{get_missing_assoc_items, render_snippet, resolve_target_trait, Cursor},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 #[derive(PartialEq)]
@@ -128,9 +128,9 @@ fn add_missing_impl_members_inner(
     let missing_items = get_missing_assoc_items(&ctx.sema, &impl_def)
         .iter()
         .map(|i| match i {
-            hir::AssocItem::Function(i) => ast::AssocItem::FnDef(i.source(ctx.db).value),
-            hir::AssocItem::TypeAlias(i) => ast::AssocItem::TypeAliasDef(i.source(ctx.db).value),
-            hir::AssocItem::Const(i) => ast::AssocItem::ConstDef(i.source(ctx.db).value),
+            hir::AssocItem::Function(i) => ast::AssocItem::FnDef(i.source(ctx.db()).value),
+            hir::AssocItem::TypeAlias(i) => ast::AssocItem::TypeAliasDef(i.source(ctx.db()).value),
+            hir::AssocItem::Const(i) => ast::AssocItem::ConstDef(i.source(ctx.db()).value),
         })
         .filter(|t| def_name(&t).is_some())
         .filter(|t| match t {
@@ -147,7 +147,7 @@ fn add_missing_impl_members_inner(
     }
 
     let target = impl_def.syntax().text_range();
-    acc.add(AssistId(assist_id), label, target, |builder| {
+    acc.add(AssistId(assist_id, AssistKind::QuickFix), label, target, |builder| {
         let n_existing_items = impl_item_list.assoc_items().count();
         let source_scope = ctx.sema.scope_for_def(trait_);
         let target_scope = ctx.sema.scope(impl_item_list.syntax());
@@ -158,6 +158,9 @@ fn add_missing_impl_members_inner(
             .map(|it| ast_transform::apply(&*ast_transform, it))
             .map(|it| match it {
                 ast::AssocItem::FnDef(def) => ast::AssocItem::FnDef(add_body(def)),
+                ast::AssocItem::TypeAliasDef(def) => {
+                    ast::AssocItem::TypeAliasDef(def.remove_bounds())
+                }
                 _ => it,
             })
             .map(|it| edit::remove_attrs_and_docs(&it));
@@ -684,4 +687,26 @@ impl Foo<T> for S<T> {
 }"#,
         )
     }
+
+    #[test]
+    fn test_assoc_type_bounds_are_removed() {
+        check_assist(
+            add_missing_impl_members,
+            r#"
+trait Tr {
+    type Ty: Copy + 'static;
+}
+
+impl Tr for ()<|> {
+}"#,
+            r#"
+trait Tr {
+    type Ty: Copy + 'static;
+}
+
+impl Tr for () {
+    $0type Ty;
+}"#,
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/add_turbo_fish.rs b/crates/ra_assists/src/handlers/add_turbo_fish.rs
index 26acf81f2..f7e1a7b05 100644
--- a/crates/ra_assists/src/handlers/add_turbo_fish.rs
+++ b/crates/ra_assists/src/handlers/add_turbo_fish.rs
@@ -4,7 +4,7 @@ use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: add_turbo_fish
@@ -45,12 +45,15 @@ pub(crate) fn add_turbo_fish(acc: &mut Assists, ctx: &AssistContext) -> Option<(
         mark::hit!(add_turbo_fish_non_generic);
         return None;
     }
-    acc.add(AssistId("add_turbo_fish"), "Add `::<>`", ident.text_range(), |builder| {
-        match ctx.config.snippet_cap {
+    acc.add(
+        AssistId("add_turbo_fish", AssistKind::RefactorRewrite),
+        "Add `::<>`",
+        ident.text_range(),
+        |builder| match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, ident.text_range().end(), "::<${0:_}>"),
             None => builder.insert(ident.text_range().end(), "::<_>"),
-        }
-    })
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/apply_demorgan.rs b/crates/ra_assists/src/handlers/apply_demorgan.rs
index 233e8fb8e..de701f8b8 100644
--- a/crates/ra_assists/src/handlers/apply_demorgan.rs
+++ b/crates/ra_assists/src/handlers/apply_demorgan.rs
@@ -1,6 +1,6 @@
 use ra_syntax::ast::{self, AstNode};
 
-use crate::{utils::invert_boolean_expression, AssistContext, AssistId, Assists};
+use crate::{utils::invert_boolean_expression, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: apply_demorgan
 //
@@ -39,11 +39,16 @@ pub(crate) fn apply_demorgan(acc: &mut Assists, ctx: &AssistContext) -> Option<(
     let rhs_range = rhs.syntax().text_range();
     let not_rhs = invert_boolean_expression(rhs);
 
-    acc.add(AssistId("apply_demorgan"), "Apply De Morgan's law", op_range, |edit| {
-        edit.replace(op_range, opposite_op);
-        edit.replace(lhs_range, format!("!({}", not_lhs.syntax().text()));
-        edit.replace(rhs_range, format!("{})", not_rhs.syntax().text()));
-    })
+    acc.add(
+        AssistId("apply_demorgan", AssistKind::RefactorRewrite),
+        "Apply De Morgan's law",
+        op_range,
+        |edit| {
+            edit.replace(op_range, opposite_op);
+            edit.replace(lhs_range, format!("!({}", not_lhs.syntax().text()));
+            edit.replace(rhs_range, format!("{})", not_rhs.syntax().text()));
+        },
+    )
 }
 
 // Return the opposite text for a given logical operator, if it makes sense
diff --git a/crates/ra_assists/src/handlers/auto_import.rs b/crates/ra_assists/src/handlers/auto_import.rs
index edf96d50e..947be3b9b 100644
--- a/crates/ra_assists/src/handlers/auto_import.rs
+++ b/crates/ra_assists/src/handlers/auto_import.rs
@@ -5,7 +5,7 @@ use hir::{
     AsAssocItem, AssocItemContainer, ModPath, Module, ModuleDef, PathResolution, Semantics, Trait,
     Type,
 };
-use ra_ide_db::{imports_locator::ImportsLocator, RootDatabase};
+use ra_ide_db::{imports_locator, RootDatabase};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode},
@@ -13,7 +13,9 @@ use ra_syntax::{
 };
 use rustc_hash::FxHashSet;
 
-use crate::{utils::insert_use_statement, AssistContext, AssistId, Assists, GroupLabel};
+use crate::{
+    utils::insert_use_statement, AssistContext, AssistId, AssistKind, Assists, GroupLabel,
+};
 
 // Assist: auto_import
 //
@@ -35,8 +37,8 @@ use crate::{utils::insert_use_statement, AssistContext, AssistId, Assists, Group
 // # pub mod std { pub mod collections { pub struct HashMap { } } }
 // ```
 pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let auto_import_assets = AutoImportAssets::new(&ctx)?;
-    let proposed_imports = auto_import_assets.search_for_imports(ctx.db);
+    let auto_import_assets = AutoImportAssets::new(ctx)?;
+    let proposed_imports = auto_import_assets.search_for_imports(ctx);
     if proposed_imports.is_empty() {
         return None;
     }
@@ -46,7 +48,7 @@ pub(crate) fn auto_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     for import in proposed_imports {
         acc.add_group(
             &group,
-            AssistId("auto_import"),
+            AssistId("auto_import", AssistKind::QuickFix),
             format!("Import `{}`", &import),
             range,
             |builder| {
@@ -127,11 +129,11 @@ impl AutoImportAssets {
         GroupLabel(name)
     }
 
-    fn search_for_imports(&self, db: &RootDatabase) -> BTreeSet<ModPath> {
+    fn search_for_imports(&self, ctx: &AssistContext) -> BTreeSet<ModPath> {
         let _p = profile("auto_import::search_for_imports");
+        let db = ctx.db();
         let current_crate = self.module_with_name_to_import.krate();
-        ImportsLocator::new(db)
-            .find_imports(&self.get_search_query())
+        imports_locator::find_imports(&ctx.sema, current_crate, &self.get_search_query())
             .into_iter()
             .filter_map(|candidate| match &self.import_candidate {
                 ImportCandidate::TraitAssocItem(assoc_item_type, _) => {
@@ -488,16 +490,17 @@ mod tests {
         check_assist(
             auto_import,
             r"
-                    //- /lib.rs crate:crate_with_macro
-                    #[macro_export]
-                    macro_rules! foo {
-                        () => ()
-                    }
+//- /lib.rs crate:crate_with_macro
+#[macro_export]
+macro_rules! foo {
+    () => ()
+}
 
-                    //- /main.rs crate:main deps:crate_with_macro
-                    fn main() {
-                        foo<|>
-                    }",
+//- /main.rs crate:main deps:crate_with_macro
+fn main() {
+    foo<|>
+}
+",
             r"use crate_with_macro::foo;
 
 fn main() {
@@ -810,6 +813,146 @@ fn main() {
     }
 
     #[test]
+    fn trait_method_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_method()
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_fn_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                dep::test_mod::TestStruct::test_func<|>tion
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                dep::test_mod::TestStruct::test_function
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_const_cross_crate() {
+        check_assist(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                dep::test_mod::TestStruct::CONST<|>
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    const CONST: bool;
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    const CONST: bool = true;
+                }
+            }
+            ",
+            r"
+            use dep::test_mod::TestTrait;
+
+            fn main() {
+                dep::test_mod::TestStruct::CONST
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn assoc_fn_as_method_cross_crate() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_func<|>tion()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                pub trait TestTrait {
+                    fn test_function();
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_function() {}
+                }
+            }
+            ",
+        );
+    }
+
+    #[test]
+    fn private_trait_cross_crate() {
+        check_assist_not_applicable(
+            auto_import,
+            r"
+            //- /main.rs crate:main deps:dep
+            fn main() {
+                let test_struct = dep::test_mod::TestStruct {};
+                test_struct.test_meth<|>od()
+            }
+            //- /dep.rs crate:dep
+            pub mod test_mod {
+                trait TestTrait {
+                    fn test_method(&self);
+                }
+                pub struct TestStruct {}
+                impl TestTrait for TestStruct {
+                    fn test_method(&self) {}
+                }
+            }
+            ",
+        );
+    }
+
+    #[test]
     fn not_applicable_for_imported_trait_for_method() {
         check_assist_not_applicable(
             auto_import,
@@ -841,4 +984,106 @@ fn main() {
             ",
         )
     }
+
+    #[test]
+    fn dep_import() {
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub struct Struct;
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    Struct<|>
+}
+",
+            r"use dep::Struct;
+
+fn main() {
+    Struct
+}
+",
+        );
+    }
+
+    #[test]
+    fn whole_segment() {
+        // Tests that only imports whose last segment matches the identifier get suggested.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub mod fmt {
+    pub trait Display {}
+}
+
+pub fn panic_fmt() {}
+
+//- /main.rs crate:main deps:dep
+struct S;
+
+impl f<|>mt::Display for S {}
+",
+            r"use dep::fmt;
+
+struct S;
+
+impl fmt::Display for S {}
+",
+        );
+    }
+
+    #[test]
+    fn macro_generated() {
+        // Tests that macro-generated items are suggested from external crates.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+macro_rules! mac {
+    () => {
+        pub struct Cheese;
+    };
+}
+
+mac!();
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    Cheese<|>;
+}
+",
+            r"use dep::Cheese;
+
+fn main() {
+    Cheese;
+}
+",
+        );
+    }
+
+    #[test]
+    fn casing() {
+        // Tests that differently cased names don't interfere and we only suggest the matching one.
+        check_assist(
+            auto_import,
+            r"
+//- /lib.rs crate:dep
+pub struct FMT;
+pub struct fmt;
+
+//- /main.rs crate:main deps:dep
+fn main() {
+    FMT<|>;
+}
+",
+            r"use dep::FMT;
+
+fn main() {
+    FMT;
+}
+",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/change_return_type_to_result.rs b/crates/ra_assists/src/handlers/change_return_type_to_result.rs
index c6baa0a57..24e5f6963 100644
--- a/crates/ra_assists/src/handlers/change_return_type_to_result.rs
+++ b/crates/ra_assists/src/handlers/change_return_type_to_result.rs
@@ -3,7 +3,8 @@ use ra_syntax::{
     AstNode, SyntaxNode,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+use test_utils::mark;
 
 // Assist: change_return_type_to_result
 //
@@ -22,14 +23,19 @@ pub(crate) fn change_return_type_to_result(acc: &mut Assists, ctx: &AssistContex
     let fn_def = ret_type.syntax().parent().and_then(ast::FnDef::cast)?;
 
     let type_ref = &ret_type.type_ref()?;
-    if type_ref.syntax().text().to_string().starts_with("Result<") {
-        return None;
+    let ret_type_str = type_ref.syntax().text().to_string();
+    let first_part_ret_type = ret_type_str.splitn(2, '<').next();
+    if let Some(ret_type_first_part) = first_part_ret_type {
+        if ret_type_first_part.ends_with("Result") {
+            mark::hit!(change_return_type_to_result_simple_return_type_already_result);
+            return None;
+        }
     }
 
     let block_expr = &fn_def.body()?;
 
     acc.add(
-        AssistId("change_return_type_to_result"),
+        AssistId("change_return_type_to_result", AssistKind::RefactorRewrite),
         "Change return type to Result",
         type_ref.syntax().text_range(),
         |builder| {
@@ -297,6 +303,29 @@ mod tests {
     }
 
     #[test]
+    fn change_return_type_to_result_simple_return_type_already_result_std() {
+        check_assist_not_applicable(
+            change_return_type_to_result,
+            r#"fn foo() -> std::result::Result<i32<|>, String> {
+                let test = "test";
+                return 42i32;
+            }"#,
+        );
+    }
+
+    #[test]
+    fn change_return_type_to_result_simple_return_type_already_result() {
+        mark::check!(change_return_type_to_result_simple_return_type_already_result);
+        check_assist_not_applicable(
+            change_return_type_to_result,
+            r#"fn foo() -> Result<i32<|>, String> {
+                let test = "test";
+                return 42i32;
+            }"#,
+        );
+    }
+
+    #[test]
     fn change_return_type_to_result_simple_with_cursor() {
         check_assist(
             change_return_type_to_result,
diff --git a/crates/ra_assists/src/handlers/change_visibility.rs b/crates/ra_assists/src/handlers/change_visibility.rs
index c21d75be0..4343b423c 100644
--- a/crates/ra_assists/src/handlers/change_visibility.rs
+++ b/crates/ra_assists/src/handlers/change_visibility.rs
@@ -2,14 +2,13 @@ use ra_syntax::{
     ast::{self, NameOwner, VisibilityOwner},
     AstNode,
     SyntaxKind::{
-        ATTR, COMMENT, CONST_DEF, ENUM_DEF, FN_DEF, MODULE, STRUCT_DEF, TRAIT_DEF, VISIBILITY,
-        WHITESPACE,
+        CONST_DEF, ENUM_DEF, FN_DEF, MODULE, STATIC_DEF, STRUCT_DEF, TRAIT_DEF, VISIBILITY,
     },
-    SyntaxNode, TextSize, T,
+    T,
 };
 use test_utils::mark;
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{utils::vis_offset, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: change_visibility
 //
@@ -30,14 +29,16 @@ pub(crate) fn change_visibility(acc: &mut Assists, ctx: &AssistContext) -> Optio
 }
 
 fn add_vis(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let item_keyword = ctx.token_at_offset().find(|leaf| match leaf.kind() {
-        T![const] | T![fn] | T![mod] | T![struct] | T![enum] | T![trait] => true,
-        _ => false,
+    let item_keyword = ctx.token_at_offset().find(|leaf| {
+        matches!(
+            leaf.kind(),
+            T![const] | T![static] | T![fn] | T![mod] | T![struct] | T![enum] | T![trait]
+        )
     });
 
     let (offset, target) = if let Some(keyword) = item_keyword {
         let parent = keyword.parent();
-        let def_kws = vec![CONST_DEF, FN_DEF, MODULE, STRUCT_DEF, ENUM_DEF, TRAIT_DEF];
+        let def_kws = vec![CONST_DEF, STATIC_DEF, FN_DEF, MODULE, STRUCT_DEF, ENUM_DEF, TRAIT_DEF];
         // Parent is not a definition, can't add visibility
         if !def_kws.iter().any(|&def_kw| def_kw == parent.kind()) {
             return None;
@@ -66,27 +67,21 @@ fn add_vis(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
         return None;
     };
 
-    acc.add(AssistId("change_visibility"), "Change visibility to pub(crate)", target, |edit| {
-        edit.insert(offset, "pub(crate) ");
-    })
-}
-
-fn vis_offset(node: &SyntaxNode) -> TextSize {
-    node.children_with_tokens()
-        .skip_while(|it| match it.kind() {
-            WHITESPACE | COMMENT | ATTR => true,
-            _ => false,
-        })
-        .next()
-        .map(|it| it.text_range().start())
-        .unwrap_or_else(|| node.text_range().start())
+    acc.add(
+        AssistId("change_visibility", AssistKind::RefactorRewrite),
+        "Change visibility to pub(crate)",
+        target,
+        |edit| {
+            edit.insert(offset, "pub(crate) ");
+        },
+    )
 }
 
 fn change_vis(acc: &mut Assists, vis: ast::Visibility) -> Option<()> {
     if vis.syntax().text() == "pub" {
         let target = vis.syntax().text_range();
         return acc.add(
-            AssistId("change_visibility"),
+            AssistId("change_visibility", AssistKind::RefactorRewrite),
             "Change Visibility to pub(crate)",
             target,
             |edit| {
@@ -97,7 +92,7 @@ fn change_vis(acc: &mut Assists, vis: ast::Visibility) -> Option<()> {
     if vis.syntax().text() == "pub(crate)" {
         let target = vis.syntax().text_range();
         return acc.add(
-            AssistId("change_visibility"),
+            AssistId("change_visibility", AssistKind::RefactorRewrite),
             "Change visibility to pub",
             target,
             |edit| {
@@ -162,6 +157,11 @@ mod tests {
     }
 
     #[test]
+    fn change_visibility_static() {
+        check_assist(change_visibility, "<|>static FOO = 3u8;", "pub(crate) static FOO = 3u8;");
+    }
+
+    #[test]
     fn change_visibility_handles_comment_attrs() {
         check_assist(
             change_visibility,
diff --git a/crates/ra_assists/src/handlers/early_return.rs b/crates/ra_assists/src/handlers/early_return.rs
index 4cc75a7ce..330459f3c 100644
--- a/crates/ra_assists/src/handlers/early_return.rs
+++ b/crates/ra_assists/src/handlers/early_return.rs
@@ -15,7 +15,7 @@ use ra_syntax::{
 use crate::{
     assist_context::{AssistContext, Assists},
     utils::invert_boolean_expression,
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: convert_to_guarded_return
@@ -99,86 +99,92 @@ pub(crate) fn convert_to_guarded_return(acc: &mut Assists, ctx: &AssistContext)
     then_block.syntax().last_child_or_token().filter(|t| t.kind() == R_CURLY)?;
 
     let target = if_expr.syntax().text_range();
-    acc.add(AssistId("convert_to_guarded_return"), "Convert to guarded return", target, |edit| {
-        let if_indent_level = IndentLevel::from_node(&if_expr.syntax());
-        let new_block = match if_let_pat {
-            None => {
-                // If.
-                let new_expr = {
-                    let then_branch =
-                        make::block_expr(once(make::expr_stmt(early_expression).into()), None);
-                    let cond = invert_boolean_expression(cond_expr);
-                    make::expr_if(make::condition(cond, None), then_branch).indent(if_indent_level)
-                };
-                replace(new_expr.syntax(), &then_block, &parent_block, &if_expr)
-            }
-            Some((path, bound_ident)) => {
-                // If-let.
-                let match_expr = {
-                    let happy_arm = {
-                        let pat = make::tuple_struct_pat(
-                            path,
-                            once(make::bind_pat(make::name("it")).into()),
-                        );
-                        let expr = {
-                            let name_ref = make::name_ref("it");
-                            let segment = make::path_segment(name_ref);
-                            let path = make::path_unqualified(segment);
-                            make::expr_path(path)
-                        };
-                        make::match_arm(once(pat.into()), expr)
+    acc.add(
+        AssistId("convert_to_guarded_return", AssistKind::RefactorRewrite),
+        "Convert to guarded return",
+        target,
+        |edit| {
+            let if_indent_level = IndentLevel::from_node(&if_expr.syntax());
+            let new_block = match if_let_pat {
+                None => {
+                    // If.
+                    let new_expr = {
+                        let then_branch =
+                            make::block_expr(once(make::expr_stmt(early_expression).into()), None);
+                        let cond = invert_boolean_expression(cond_expr);
+                        make::expr_if(make::condition(cond, None), then_branch)
+                            .indent(if_indent_level)
                     };
+                    replace(new_expr.syntax(), &then_block, &parent_block, &if_expr)
+                }
+                Some((path, bound_ident)) => {
+                    // If-let.
+                    let match_expr = {
+                        let happy_arm = {
+                            let pat = make::tuple_struct_pat(
+                                path,
+                                once(make::bind_pat(make::name("it")).into()),
+                            );
+                            let expr = {
+                                let name_ref = make::name_ref("it");
+                                let segment = make::path_segment(name_ref);
+                                let path = make::path_unqualified(segment);
+                                make::expr_path(path)
+                            };
+                            make::match_arm(once(pat.into()), expr)
+                        };
 
-                    let sad_arm = make::match_arm(
-                        // FIXME: would be cool to use `None` or `Err(_)` if appropriate
-                        once(make::placeholder_pat().into()),
-                        early_expression,
-                    );
+                        let sad_arm = make::match_arm(
+                            // FIXME: would be cool to use `None` or `Err(_)` if appropriate
+                            once(make::placeholder_pat().into()),
+                            early_expression,
+                        );
 
-                    make::expr_match(cond_expr, make::match_arm_list(vec![happy_arm, sad_arm]))
-                };
+                        make::expr_match(cond_expr, make::match_arm_list(vec![happy_arm, sad_arm]))
+                    };
 
-                let let_stmt = make::let_stmt(
-                    make::bind_pat(make::name(&bound_ident.syntax().to_string())).into(),
-                    Some(match_expr),
+                    let let_stmt = make::let_stmt(
+                        make::bind_pat(make::name(&bound_ident.syntax().to_string())).into(),
+                        Some(match_expr),
+                    );
+                    let let_stmt = let_stmt.indent(if_indent_level);
+                    replace(let_stmt.syntax(), &then_block, &parent_block, &if_expr)
+                }
+            };
+            edit.replace_ast(parent_block, ast::BlockExpr::cast(new_block).unwrap());
+
+            fn replace(
+                new_expr: &SyntaxNode,
+                then_block: &ast::BlockExpr,
+                parent_block: &ast::BlockExpr,
+                if_expr: &ast::IfExpr,
+            ) -> SyntaxNode {
+                let then_block_items = then_block.dedent(IndentLevel(1));
+                let end_of_then = then_block_items.syntax().last_child_or_token().unwrap();
+                let end_of_then =
+                    if end_of_then.prev_sibling_or_token().map(|n| n.kind()) == Some(WHITESPACE) {
+                        end_of_then.prev_sibling_or_token().unwrap()
+                    } else {
+                        end_of_then
+                    };
+                let mut then_statements = new_expr.children_with_tokens().chain(
+                    then_block_items
+                        .syntax()
+                        .children_with_tokens()
+                        .skip(1)
+                        .take_while(|i| *i != end_of_then),
                 );
-                let let_stmt = let_stmt.indent(if_indent_level);
-                replace(let_stmt.syntax(), &then_block, &parent_block, &if_expr)
+                replace_children(
+                    &parent_block.syntax(),
+                    RangeInclusive::new(
+                        if_expr.clone().syntax().clone().into(),
+                        if_expr.syntax().clone().into(),
+                    ),
+                    &mut then_statements,
+                )
             }
-        };
-        edit.replace_ast(parent_block, ast::BlockExpr::cast(new_block).unwrap());
-
-        fn replace(
-            new_expr: &SyntaxNode,
-            then_block: &ast::BlockExpr,
-            parent_block: &ast::BlockExpr,
-            if_expr: &ast::IfExpr,
-        ) -> SyntaxNode {
-            let then_block_items = then_block.dedent(IndentLevel::from(1));
-            let end_of_then = then_block_items.syntax().last_child_or_token().unwrap();
-            let end_of_then =
-                if end_of_then.prev_sibling_or_token().map(|n| n.kind()) == Some(WHITESPACE) {
-                    end_of_then.prev_sibling_or_token().unwrap()
-                } else {
-                    end_of_then
-                };
-            let mut then_statements = new_expr.children_with_tokens().chain(
-                then_block_items
-                    .syntax()
-                    .children_with_tokens()
-                    .skip(1)
-                    .take_while(|i| *i != end_of_then),
-            );
-            replace_children(
-                &parent_block.syntax(),
-                RangeInclusive::new(
-                    if_expr.clone().syntax().clone().into(),
-                    if_expr.syntax().clone().into(),
-                ),
-                &mut then_statements,
-            )
-        }
-    })
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
new file mode 100644
index 000000000..2b8e273b3
--- /dev/null
+++ b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -0,0 +1,321 @@
+use hir::{EnumVariant, Module, ModuleDef, Name};
+use ra_db::FileId;
+use ra_fmt::leading_indent;
+use ra_ide_db::{defs::Definition, search::Reference, RootDatabase};
+use ra_syntax::{
+    algo::find_node_at_offset,
+    ast::{self, ArgListOwner, AstNode, NameOwner, VisibilityOwner},
+    SourceFile, SyntaxNode, TextRange, TextSize,
+};
+use rustc_hash::FxHashSet;
+
+use crate::{
+    assist_context::AssistBuilder, utils::insert_use_statement, AssistContext, AssistId,
+    AssistKind, Assists,
+};
+
+// Assist: extract_struct_from_enum_variant
+//
+// Extracts a struct from enum variant.
+//
+// ```
+// enum A { <|>One(u32, u32) }
+// ```
+// ->
+// ```
+// struct One(pub u32, pub u32);
+//
+// enum A { One(One) }
+// ```
+pub(crate) fn extract_struct_from_enum_variant(
+    acc: &mut Assists,
+    ctx: &AssistContext,
+) -> Option<()> {
+    let variant = ctx.find_node_at_offset::<ast::EnumVariant>()?;
+    let field_list = match variant.kind() {
+        ast::StructKind::Tuple(field_list) => field_list,
+        _ => return None,
+    };
+    let variant_name = variant.name()?.to_string();
+    let variant_hir = ctx.sema.to_def(&variant)?;
+    if existing_struct_def(ctx.db(), &variant_name, &variant_hir) {
+        return None;
+    }
+    let enum_ast = variant.parent_enum();
+    let visibility = enum_ast.visibility();
+    let enum_hir = ctx.sema.to_def(&enum_ast)?;
+    let variant_hir_name = variant_hir.name(ctx.db());
+    let enum_module_def = ModuleDef::from(enum_hir);
+    let current_module = enum_hir.module(ctx.db());
+    let target = variant.syntax().text_range();
+    acc.add(
+        AssistId("extract_struct_from_enum_variant", AssistKind::RefactorRewrite),
+        "Extract struct from enum variant",
+        target,
+        |builder| {
+            let definition = Definition::ModuleDef(ModuleDef::EnumVariant(variant_hir));
+            let res = definition.find_usages(&ctx.sema, None);
+            let start_offset = variant.parent_enum().syntax().text_range().start();
+            let mut visited_modules_set = FxHashSet::default();
+            visited_modules_set.insert(current_module);
+            for reference in res {
+                let source_file = ctx.sema.parse(reference.file_range.file_id);
+                update_reference(
+                    ctx,
+                    builder,
+                    reference,
+                    &source_file,
+                    &enum_module_def,
+                    &variant_hir_name,
+                    &mut visited_modules_set,
+                );
+            }
+            extract_struct_def(
+                builder,
+                enum_ast.syntax(),
+                &variant_name,
+                &field_list.to_string(),
+                start_offset,
+                ctx.frange.file_id,
+                &visibility,
+            );
+            let list_range = field_list.syntax().text_range();
+            update_variant(builder, &variant_name, ctx.frange.file_id, list_range);
+        },
+    )
+}
+
+fn existing_struct_def(db: &RootDatabase, variant_name: &str, variant: &EnumVariant) -> bool {
+    variant
+        .parent_enum(db)
+        .module(db)
+        .scope(db, None)
+        .into_iter()
+        .any(|(name, _)| name.to_string() == variant_name.to_string())
+}
+
+fn insert_import(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    path: &ast::PathExpr,
+    module: &Module,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+) -> Option<()> {
+    let db = ctx.db();
+    let mod_path = module.find_use_path(db, enum_module_def.clone());
+    if let Some(mut mod_path) = mod_path {
+        mod_path.segments.pop();
+        mod_path.segments.push(variant_hir_name.clone());
+        insert_use_statement(path.syntax(), &mod_path, ctx, builder.text_edit_builder());
+    }
+    Some(())
+}
+
+fn extract_struct_def(
+    builder: &mut AssistBuilder,
+    enum_ast: &SyntaxNode,
+    variant_name: &str,
+    variant_list: &str,
+    start_offset: TextSize,
+    file_id: FileId,
+    visibility: &Option<ast::Visibility>,
+) -> Option<()> {
+    let visibility_string = if let Some(visibility) = visibility {
+        format!("{} ", visibility.to_string())
+    } else {
+        "".to_string()
+    };
+    let indent = if let Some(indent) = leading_indent(enum_ast) {
+        indent.to_string()
+    } else {
+        "".to_string()
+    };
+    let struct_def = format!(
+        r#"{}struct {}{};
+
+{}"#,
+        visibility_string,
+        variant_name,
+        list_with_visibility(variant_list),
+        indent
+    );
+    builder.edit_file(file_id);
+    builder.insert(start_offset, struct_def);
+    Some(())
+}
+
+fn update_variant(
+    builder: &mut AssistBuilder,
+    variant_name: &str,
+    file_id: FileId,
+    list_range: TextRange,
+) -> Option<()> {
+    let inside_variant_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(file_id);
+    builder.replace(inside_variant_range, variant_name);
+    Some(())
+}
+
+fn update_reference(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    reference: Reference,
+    source_file: &SourceFile,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+    visited_modules_set: &mut FxHashSet<Module>,
+) -> Option<()> {
+    let path_expr: ast::PathExpr = find_node_at_offset::<ast::PathExpr>(
+        source_file.syntax(),
+        reference.file_range.range.start(),
+    )?;
+    let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
+    let list = call.arg_list()?;
+    let segment = path_expr.path()?.segment()?;
+    let module = ctx.sema.scope(&path_expr.syntax()).module()?;
+    let list_range = list.syntax().text_range();
+    let inside_list_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(reference.file_range.file_id);
+    if !visited_modules_set.contains(&module) {
+        if insert_import(ctx, builder, &path_expr, &module, enum_module_def, variant_hir_name)
+            .is_some()
+        {
+            visited_modules_set.insert(module);
+        }
+    }
+    builder.replace(inside_list_range, format!("{}{}", segment, list));
+    Some(())
+}
+
+fn list_with_visibility(list: &str) -> String {
+    list.split(',')
+        .map(|part| {
+            let index = if part.chars().next().unwrap() == '(' { 1usize } else { 0 };
+            let mut mod_part = part.trim().to_string();
+            mod_part.insert_str(index, "pub ");
+            mod_part
+        })
+        .collect::<Vec<String>>()
+        .join(", ")
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::{
+        tests::{check_assist, check_assist_not_applicable},
+        utils::FamousDefs,
+    };
+
+    use super::*;
+
+    #[test]
+    fn test_extract_struct_several_fields() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32, u32) }",
+            r#"struct One(pub u32, pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_one_field() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32) }",
+            r#"struct One(pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_pub_visibility() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "pub enum A { <|>One(u32, u32) }",
+            r#"pub struct One(pub u32, pub u32);
+
+pub enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_with_complex_imports() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"mod my_mod {
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(1, 1);
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(1, 1);
+        }
+
+        pub enum MyEnum {
+            <|>MyField(u8, u8),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(1, 1);
+}"#,
+            r#"use my_mod::my_other_mod::MyField;
+
+mod my_mod {
+    use my_other_mod::MyField;
+
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(MyField(1, 1));
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(MyField(1, 1));
+        }
+
+        pub struct MyField(pub u8, pub u8);
+
+        pub enum MyEnum {
+            MyField(MyField),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(MyField(1, 1));
+}"#,
+        );
+    }
+
+    fn check_not_applicable(ra_fixture: &str) {
+        let fixture =
+            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
+        check_assist_not_applicable(extract_struct_from_enum_variant, &fixture)
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_for_element_with_no_fields() {
+        check_not_applicable("enum A { <|>One }");
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_if_struct_exists() {
+        check_not_applicable(
+            r#"struct One;
+        enum A { <|>One(u8) }"#,
+        );
+    }
+}
diff --git a/crates/ra_assists/src/handlers/introduce_variable.rs b/crates/ra_assists/src/handlers/extract_variable.rs
index 31d6539f7..481baf1a4 100644
--- a/crates/ra_assists/src/handlers/introduce_variable.rs
+++ b/crates/ra_assists/src/handlers/extract_variable.rs
@@ -9,9 +9,9 @@ use ra_syntax::{
 use stdx::format_to;
 use test_utils::mark;
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: introduce_variable
+// Assist: extract_variable
 //
 // Extracts subexpression into a variable.
 //
@@ -27,13 +27,13 @@ use crate::{AssistContext, AssistId, Assists};
 //     var_name * 4;
 // }
 // ```
-pub(crate) fn introduce_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     if ctx.frange.range.is_empty() {
         return None;
     }
     let node = ctx.covering_element();
     if node.kind() == COMMENT {
-        mark::hit!(introduce_var_in_comment_is_not_applicable);
+        mark::hit!(extract_var_in_comment_is_not_applicable);
         return None;
     }
     let expr = node.ancestors().find_map(valid_target_expr)?;
@@ -43,65 +43,85 @@ pub(crate) fn introduce_variable(acc: &mut Assists, ctx: &AssistContext) -> Opti
         return None;
     }
     let target = expr.syntax().text_range();
-    acc.add(AssistId("introduce_variable"), "Extract into variable", target, move |edit| {
-        let mut buf = String::new();
-
-        if wrap_in_block {
-            buf.push_str("{ let var_name = ");
-        } else {
-            buf.push_str("let var_name = ");
-        };
-        format_to!(buf, "{}", expr.syntax());
-
-        let full_stmt = ast::ExprStmt::cast(anchor_stmt.clone());
-        let is_full_stmt = if let Some(expr_stmt) = &full_stmt {
-            Some(expr.syntax().clone()) == expr_stmt.expr().map(|e| e.syntax().clone())
-        } else {
-            false
-        };
-        if is_full_stmt {
-            mark::hit!(test_introduce_var_expr_stmt);
-            if full_stmt.unwrap().semicolon_token().is_none() {
-                buf.push_str(";");
+    acc.add(
+        AssistId("extract_variable", AssistKind::RefactorExtract),
+        "Extract into variable",
+        target,
+        move |edit| {
+            let field_shorthand = match expr.syntax().parent().and_then(ast::RecordField::cast) {
+                Some(field) => field.name_ref(),
+                None => None,
+            };
+
+            let mut buf = String::new();
+
+            let var_name = match &field_shorthand {
+                Some(it) => it.to_string(),
+                None => "var_name".to_string(),
+            };
+            let expr_range = match &field_shorthand {
+                Some(it) => it.syntax().text_range().cover(expr.syntax().text_range()),
+                None => expr.syntax().text_range(),
+            };
+
+            if wrap_in_block {
+                format_to!(buf, "{{ let {} = ", var_name);
+            } else {
+                format_to!(buf, "let {} = ", var_name);
+            };
+            format_to!(buf, "{}", expr.syntax());
+
+            let full_stmt = ast::ExprStmt::cast(anchor_stmt.clone());
+            let is_full_stmt = if let Some(expr_stmt) = &full_stmt {
+                Some(expr.syntax().clone()) == expr_stmt.expr().map(|e| e.syntax().clone())
+            } else {
+                false
+            };
+            if is_full_stmt {
+                mark::hit!(test_extract_var_expr_stmt);
+                if full_stmt.unwrap().semicolon_token().is_none() {
+                    buf.push_str(";");
+                }
+                match ctx.config.snippet_cap {
+                    Some(cap) => {
+                        let snip = buf
+                            .replace(&format!("let {}", var_name), &format!("let $0{}", var_name));
+                        edit.replace_snippet(cap, expr_range, snip)
+                    }
+                    None => edit.replace(expr_range, buf),
+                }
+                return;
+            }
+
+            buf.push_str(";");
+
+            // We want to maintain the indent level,
+            // but we do not want to duplicate possible
+            // extra newlines in the indent block
+            let text = indent.text();
+            if text.starts_with('\n') {
+                buf.push_str("\n");
+                buf.push_str(text.trim_start_matches('\n'));
+            } else {
+                buf.push_str(text);
             }
-            let offset = expr.syntax().text_range();
+
+            edit.replace(expr_range, var_name.clone());
+            let offset = anchor_stmt.text_range().start();
             match ctx.config.snippet_cap {
                 Some(cap) => {
-                    let snip = buf.replace("let var_name", "let $0var_name");
-                    edit.replace_snippet(cap, offset, snip)
+                    let snip =
+                        buf.replace(&format!("let {}", var_name), &format!("let $0{}", var_name));
+                    edit.insert_snippet(cap, offset, snip)
                 }
-                None => edit.replace(offset, buf),
+                None => edit.insert(offset, buf),
             }
-            return;
-        }
 
-        buf.push_str(";");
-
-        // We want to maintain the indent level,
-        // but we do not want to duplicate possible
-        // extra newlines in the indent block
-        let text = indent.text();
-        if text.starts_with('\n') {
-            buf.push_str("\n");
-            buf.push_str(text.trim_start_matches('\n'));
-        } else {
-            buf.push_str(text);
-        }
-
-        edit.replace(expr.syntax().text_range(), "var_name".to_string());
-        let offset = anchor_stmt.text_range().start();
-        match ctx.config.snippet_cap {
-            Some(cap) => {
-                let snip = buf.replace("let var_name", "let $0var_name");
-                edit.insert_snippet(cap, offset, snip)
+            if wrap_in_block {
+                edit.insert(anchor_stmt.text_range().end(), " }");
             }
-            None => edit.insert(offset, buf),
-        }
-
-        if wrap_in_block {
-            edit.insert(anchor_stmt.text_range().end(), " }");
-        }
-    })
+        },
+    )
 }
 
 /// Check whether the node is a valid expression which can be extracted to a variable.
@@ -118,7 +138,7 @@ fn valid_target_expr(node: SyntaxNode) -> Option<ast::Expr> {
     }
 }
 
-/// Returns the syntax node which will follow the freshly introduced var
+/// Returns the syntax node which will follow the freshly extractd var
 /// and a boolean indicating whether we have to wrap it within a { } block
 /// to produce correct code.
 /// It can be a statement, the last in a block expression or a wanna be block
@@ -127,7 +147,7 @@ fn anchor_stmt(expr: ast::Expr) -> Option<(SyntaxNode, bool)> {
     expr.syntax().ancestors().find_map(|node| {
         if let Some(expr) = node.parent().and_then(ast::BlockExpr::cast).and_then(|it| it.expr()) {
             if expr.syntax() == &node {
-                mark::hit!(test_introduce_var_last_expr);
+                mark::hit!(test_extract_var_last_expr);
                 return Some((node, false));
             }
         }
@@ -155,9 +175,9 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_introduce_var_simple() {
+    fn test_extract_var_simple() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             r#"
 fn foo() {
     foo(<|>1 + 1<|>);
@@ -171,16 +191,16 @@ fn foo() {
     }
 
     #[test]
-    fn introduce_var_in_comment_is_not_applicable() {
-        mark::check!(introduce_var_in_comment_is_not_applicable);
-        check_assist_not_applicable(introduce_variable, "fn main() { 1 + /* <|>comment<|> */ 1; }");
+    fn extract_var_in_comment_is_not_applicable() {
+        mark::check!(extract_var_in_comment_is_not_applicable);
+        check_assist_not_applicable(extract_variable, "fn main() { 1 + /* <|>comment<|> */ 1; }");
     }
 
     #[test]
-    fn test_introduce_var_expr_stmt() {
-        mark::check!(test_introduce_var_expr_stmt);
+    fn test_extract_var_expr_stmt() {
+        mark::check!(test_extract_var_expr_stmt);
         check_assist(
-            introduce_variable,
+            extract_variable,
             r#"
 fn foo() {
     <|>1 + 1<|>;
@@ -191,7 +211,7 @@ fn foo() {
 }"#,
         );
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() {
     <|>{ let x = 0; x }<|>
@@ -206,9 +226,9 @@ fn foo() {
     }
 
     #[test]
-    fn test_introduce_var_part_of_expr_stmt() {
+    fn test_extract_var_part_of_expr_stmt() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() {
     <|>1<|> + 1;
@@ -222,38 +242,42 @@ fn foo() {
     }
 
     #[test]
-    fn test_introduce_var_last_expr() {
-        mark::check!(test_introduce_var_last_expr);
+    fn test_extract_var_last_expr() {
+        mark::check!(test_extract_var_last_expr);
         check_assist(
-            introduce_variable,
-            "
+            extract_variable,
+            r#"
 fn foo() {
     bar(<|>1 + 1<|>)
-}",
-            "
+}
+"#,
+            r#"
 fn foo() {
     let $0var_name = 1 + 1;
     bar(var_name)
-}",
+}
+"#,
         );
         check_assist(
-            introduce_variable,
-            "
+            extract_variable,
+            r#"
 fn foo() {
     <|>bar(1 + 1)<|>
-}",
-            "
+}
+"#,
+            r#"
 fn foo() {
     let $0var_name = bar(1 + 1);
     var_name
-}",
+}
+"#,
         )
     }
 
     #[test]
-    fn test_introduce_var_in_match_arm_no_block() {
+    fn test_extract_var_in_match_arm_no_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let x = true;
@@ -276,9 +300,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_match_arm_with_block() {
+    fn test_extract_var_in_match_arm_with_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let x = true;
@@ -308,9 +332,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_closure_no_block() {
+    fn test_extract_var_in_closure_no_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let lambda = |x: u32| <|>x * 2<|>;
@@ -325,9 +349,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_in_closure_with_block() {
+    fn test_extract_var_in_closure_with_block() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let lambda = |x: u32| { <|>x * 2<|> };
@@ -342,9 +366,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_path_simple() {
+    fn test_extract_var_path_simple() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let o = <|>Some(true)<|>;
@@ -360,9 +384,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_path_method() {
+    fn test_extract_var_path_method() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let v = <|>bar.foo()<|>;
@@ -378,9 +402,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_return() {
+    fn test_extract_var_return() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() -> u32 {
     <|>return 2 + 2<|>;
@@ -396,9 +420,9 @@ fn foo() -> u32 {
     }
 
     #[test]
-    fn test_introduce_var_does_not_add_extra_whitespace() {
+    fn test_extract_var_does_not_add_extra_whitespace() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() -> u32 {
 
@@ -417,7 +441,7 @@ fn foo() -> u32 {
         );
 
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() -> u32 {
 
@@ -434,7 +458,7 @@ fn foo() -> u32 {
         );
 
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn foo() -> u32 {
     let foo = 1;
@@ -460,9 +484,9 @@ fn foo() -> u32 {
     }
 
     #[test]
-    fn test_introduce_var_break() {
+    fn test_extract_var_break() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let result = loop {
@@ -482,9 +506,9 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_for_cast() {
+    fn test_extract_var_for_cast() {
         check_assist(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let v = <|>0f32 as u32<|>;
@@ -500,22 +524,48 @@ fn main() {
     }
 
     #[test]
-    fn test_introduce_var_for_return_not_applicable() {
-        check_assist_not_applicable(introduce_variable, "fn foo() { <|>return<|>; } ");
+    fn extract_var_field_shorthand() {
+        check_assist(
+            extract_variable,
+            r#"
+struct S {
+    foo: i32
+}
+
+fn main() {
+    S { foo: <|>1 + 1<|> }
+}
+"#,
+            r#"
+struct S {
+    foo: i32
+}
+
+fn main() {
+    let $0foo = 1 + 1;
+    S { foo }
+}
+"#,
+        )
+    }
+
+    #[test]
+    fn test_extract_var_for_return_not_applicable() {
+        check_assist_not_applicable(extract_variable, "fn foo() { <|>return<|>; } ");
     }
 
     #[test]
-    fn test_introduce_var_for_break_not_applicable() {
-        check_assist_not_applicable(introduce_variable, "fn main() { loop { <|>break<|>; }; }");
+    fn test_extract_var_for_break_not_applicable() {
+        check_assist_not_applicable(extract_variable, "fn main() { loop { <|>break<|>; }; }");
     }
 
     // FIXME: This is not quite correct, but good enough(tm) for the sorting heuristic
     #[test]
-    fn introduce_var_target() {
-        check_assist_target(introduce_variable, "fn foo() -> u32 { <|>return 2 + 2<|>; }", "2 + 2");
+    fn extract_var_target() {
+        check_assist_target(extract_variable, "fn foo() -> u32 { <|>return 2 + 2<|>; }", "2 + 2");
 
         check_assist_target(
-            introduce_variable,
+            extract_variable,
             "
 fn main() {
     let x = true;
diff --git a/crates/ra_assists/src/handlers/fill_match_arms.rs b/crates/ra_assists/src/handlers/fill_match_arms.rs
index cc303285b..708e1bc6c 100644
--- a/crates/ra_assists/src/handlers/fill_match_arms.rs
+++ b/crates/ra_assists/src/handlers/fill_match_arms.rs
@@ -8,7 +8,7 @@ use test_utils::mark;
 
 use crate::{
     utils::{render_snippet, Cursor, FamousDefs},
-    AssistContext, AssistId, Assists,
+    AssistContext, AssistId, AssistKind, Assists,
 };
 
 // Assist: fill_match_arms
@@ -51,11 +51,11 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
     let module = ctx.sema.scope(expr.syntax()).module()?;
 
     let missing_arms: Vec<MatchArm> = if let Some(enum_def) = resolve_enum_def(&ctx.sema, &expr) {
-        let variants = enum_def.variants(ctx.db);
+        let variants = enum_def.variants(ctx.db());
 
         let mut variants = variants
             .into_iter()
-            .filter_map(|variant| build_pat(ctx.db, module, variant))
+            .filter_map(|variant| build_pat(ctx.db(), module, variant))
             .filter(|variant_pat| is_variant_missing(&mut arms, variant_pat))
             .map(|pat| make::match_arm(iter::once(pat), make::expr_empty_block()))
             .collect::<Vec<_>>();
@@ -84,11 +84,11 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
         // where each tuple represents a proposed match arm.
         enum_defs
             .into_iter()
-            .map(|enum_def| enum_def.variants(ctx.db))
+            .map(|enum_def| enum_def.variants(ctx.db()))
             .multi_cartesian_product()
             .map(|variants| {
                 let patterns =
-                    variants.into_iter().filter_map(|variant| build_pat(ctx.db, module, variant));
+                    variants.into_iter().filter_map(|variant| build_pat(ctx.db(), module, variant));
                 ast::Pat::from(make::tuple_pat(patterns))
             })
             .filter(|variant_pat| is_variant_missing(&mut arms, variant_pat))
@@ -103,24 +103,37 @@ pub(crate) fn fill_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<
     }
 
     let target = match_expr.syntax().text_range();
-    acc.add(AssistId("fill_match_arms"), "Fill match arms", target, |builder| {
-        let new_arm_list = match_arm_list.remove_placeholder();
-        let n_old_arms = new_arm_list.arms().count();
-        let new_arm_list = new_arm_list.append_arms(missing_arms);
-        let first_new_arm = new_arm_list.arms().nth(n_old_arms);
-        let old_range = match_arm_list.syntax().text_range();
-        match (first_new_arm, ctx.config.snippet_cap) {
-            (Some(first_new_arm), Some(cap)) => {
-                let snippet = render_snippet(
-                    cap,
-                    new_arm_list.syntax(),
-                    Cursor::Before(first_new_arm.syntax()),
-                );
-                builder.replace_snippet(cap, old_range, snippet);
-            }
-            _ => builder.replace(old_range, new_arm_list.to_string()),
-        }
-    })
+    acc.add(
+        AssistId("fill_match_arms", AssistKind::QuickFix),
+        "Fill match arms",
+        target,
+        |builder| {
+            let new_arm_list = match_arm_list.remove_placeholder();
+            let n_old_arms = new_arm_list.arms().count();
+            let new_arm_list = new_arm_list.append_arms(missing_arms);
+            let first_new_arm = new_arm_list.arms().nth(n_old_arms);
+            let old_range = match_arm_list.syntax().text_range();
+            match (first_new_arm, ctx.config.snippet_cap) {
+                (Some(first_new_arm), Some(cap)) => {
+                    let extend_lifetime;
+                    let cursor = match first_new_arm
+                        .syntax()
+                        .descendants()
+                        .find_map(ast::PlaceholderPat::cast)
+                    {
+                        Some(it) => {
+                            extend_lifetime = it.syntax().clone();
+                            Cursor::Replace(&extend_lifetime)
+                        }
+                        None => Cursor::Before(first_new_arm.syntax()),
+                    };
+                    let snippet = render_snippet(cap, new_arm_list.syntax(), cursor);
+                    builder.replace_snippet(cap, old_range, snippet);
+                }
+                _ => builder.replace(old_range, new_arm_list.to_string()),
+            }
+        },
+    )
 }
 
 fn is_variant_missing(existing_arms: &mut Vec<MatchArm>, var: &Pat) -> bool {
@@ -136,8 +149,20 @@ fn is_variant_missing(existing_arms: &mut Vec<MatchArm>, var: &Pat) -> bool {
 }
 
 fn does_pat_match_variant(pat: &Pat, var: &Pat) -> bool {
-    let pat_head = pat.syntax().first_child().map(|node| node.text());
-    let var_head = var.syntax().first_child().map(|node| node.text());
+    let first_node_text = |pat: &Pat| pat.syntax().first_child().map(|node| node.text());
+
+    let pat_head = match pat {
+        Pat::BindPat(bind_pat) => {
+            if let Some(p) = bind_pat.pat() {
+                first_node_text(&p)
+            } else {
+                return false;
+            }
+        }
+        pat => first_node_text(pat),
+    };
+
+    let var_head = first_node_text(var);
 
     pat_head == var_head
 }
@@ -274,30 +299,22 @@ mod tests {
         check_assist(
             fill_match_arms,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs(Option<i32>),
-            }
-            fn main() {
-                match A::As<|> {
-                    A::Cs(_) | A::Bs => {}
-                }
-            }
-            "#,
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+    match A::As<|> {
+        A::Cs(_) | A::Bs => {}
+    }
+}
+"#,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs(Option<i32>),
-            }
-            fn main() {
-                match A::As {
-                    A::Cs(_) | A::Bs => {}
-                    $0A::As => {}
-                }
-            }
-            "#,
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+    match A::As {
+        A::Cs(_) | A::Bs => {}
+        $0A::As => {}
+    }
+}
+"#,
         );
     }
 
@@ -306,47 +323,55 @@ mod tests {
         check_assist(
             fill_match_arms,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs,
-                Ds(String),
-                Es(B),
-            }
-            enum B {
-                Xs,
-                Ys,
-            }
-            fn main() {
-                match A::As<|> {
-                    A::Bs if 0 < 1 => {}
-                    A::Ds(_value) => { let x = 1; }
-                    A::Es(B::Xs) => (),
-                }
-            }
-            "#,
+enum A { As, Bs, Cs, Ds(String), Es(B) }
+enum B { Xs, Ys }
+fn main() {
+    match A::As<|> {
+        A::Bs if 0 < 1 => {}
+        A::Ds(_value) => { let x = 1; }
+        A::Es(B::Xs) => (),
+    }
+}
+"#,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs,
-                Ds(String),
-                Es(B),
-            }
-            enum B {
-                Xs,
-                Ys,
-            }
-            fn main() {
-                match A::As {
-                    A::Bs if 0 < 1 => {}
-                    A::Ds(_value) => { let x = 1; }
-                    A::Es(B::Xs) => (),
-                    $0A::As => {}
-                    A::Cs => {}
-                }
-            }
-            "#,
+enum A { As, Bs, Cs, Ds(String), Es(B) }
+enum B { Xs, Ys }
+fn main() {
+    match A::As {
+        A::Bs if 0 < 1 => {}
+        A::Ds(_value) => { let x = 1; }
+        A::Es(B::Xs) => (),
+        $0A::As => {}
+        A::Cs => {}
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn partial_fill_bind_pat() {
+        check_assist(
+            fill_match_arms,
+            r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+    match A::As<|> {
+        A::As(_) => {}
+        a @ A::Bs(_) => {}
+    }
+}
+"#,
+            r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+    match A::As {
+        A::As(_) => {}
+        a @ A::Bs(_) => {}
+        A::Cs(${0:_}) => {}
+    }
+}
+"#,
         );
     }
 
@@ -355,39 +380,27 @@ mod tests {
         check_assist(
             fill_match_arms,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs(String),
-                Ds(String, String),
-                Es { x: usize, y: usize }
-            }
+enum A { As, Bs, Cs(String), Ds(String, String), Es { x: usize, y: usize } }
 
-            fn main() {
-                let a = A::As;
-                match a<|> {}
-            }
-            "#,
+fn main() {
+    let a = A::As;
+    match a<|> {}
+}
+"#,
             r#"
-            enum A {
-                As,
-                Bs,
-                Cs(String),
-                Ds(String, String),
-                Es { x: usize, y: usize }
-            }
+enum A { As, Bs, Cs(String), Ds(String, String), Es { x: usize, y: usize } }
 
-            fn main() {
-                let a = A::As;
-                match a {
-                    $0A::As => {}
-                    A::Bs => {}
-                    A::Cs(_) => {}
-                    A::Ds(_, _) => {}
-                    A::Es { x, y } => {}
-                }
-            }
-            "#,
+fn main() {
+    let a = A::As;
+    match a {
+        $0A::As => {}
+        A::Bs => {}
+        A::Cs(_) => {}
+        A::Ds(_, _) => {}
+        A::Es { x, y } => {}
+    }
+}
+"#,
         );
     }
 
@@ -717,9 +730,9 @@ mod tests {
 fn foo(opt: Option<i32>) {
     match opt<|> {
     }
-}"#;
-        let before =
-            &format!("//- main.rs crate:main deps:core\n{}{}", before, FamousDefs::FIXTURE);
+}
+"#;
+        let before = &format!("//- /main.rs crate:main deps:core{}{}", before, FamousDefs::FIXTURE);
 
         check_assist(
             fill_match_arms,
@@ -727,7 +740,7 @@ fn foo(opt: Option<i32>) {
             r#"
 fn foo(opt: Option<i32>) {
     match opt {
-        $0Some(_) => {}
+        Some(${0:_}) => {}
         None => {}
     }
 }
diff --git a/crates/ra_assists/src/handlers/fix_visibility.rs b/crates/ra_assists/src/handlers/fix_visibility.rs
index 9ec42f568..e212557c8 100644
--- a/crates/ra_assists/src/handlers/fix_visibility.rs
+++ b/crates/ra_assists/src/handlers/fix_visibility.rs
@@ -1,12 +1,8 @@
 use hir::{db::HirDatabase, HasSource, HasVisibility, PathResolution};
 use ra_db::FileId;
-use ra_syntax::{
-    ast, AstNode,
-    SyntaxKind::{ATTR, COMMENT, WHITESPACE},
-    SyntaxNode, TextRange, TextSize,
-};
+use ra_syntax::{ast, AstNode, TextRange, TextSize};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{utils::vis_offset, AssistContext, AssistId, AssistKind, Assists};
 
 // FIXME: this really should be a fix for diagnostic, rather than an assist.
 
@@ -45,14 +41,14 @@ fn add_vis_to_referenced_module_def(acc: &mut Assists, ctx: &AssistContext) -> O
     };
 
     let current_module = ctx.sema.scope(&path.syntax()).module()?;
-    let target_module = def.module(ctx.db)?;
+    let target_module = def.module(ctx.db())?;
 
-    let vis = target_module.visibility_of(ctx.db, &def)?;
-    if vis.is_visible_from(ctx.db, current_module.into()) {
+    let vis = target_module.visibility_of(ctx.db(), &def)?;
+    if vis.is_visible_from(ctx.db(), current_module.into()) {
         return None;
     };
 
-    let (offset, target, target_file, target_name) = target_data_for_def(ctx.db, def)?;
+    let (offset, target, target_file, target_name) = target_data_for_def(ctx.db(), def)?;
 
     let missing_visibility =
         if current_module.krate() == target_module.krate() { "pub(crate)" } else { "pub" };
@@ -62,8 +58,8 @@ fn add_vis_to_referenced_module_def(acc: &mut Assists, ctx: &AssistContext) -> O
         Some(name) => format!("Change visibility of {} to {}", name, missing_visibility),
     };
 
-    acc.add(AssistId("fix_visibility"), assist_label, target, |builder| {
-        builder.set_file(target_file);
+    acc.add(AssistId("fix_visibility", AssistKind::QuickFix), assist_label, target, |builder| {
+        builder.edit_file(target_file);
         match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, offset, format!("$0{} ", missing_visibility)),
             None => builder.insert(offset, format!("{} ", missing_visibility)),
@@ -76,16 +72,16 @@ fn add_vis_to_referenced_record_field(acc: &mut Assists, ctx: &AssistContext) ->
     let (record_field_def, _) = ctx.sema.resolve_record_field(&record_field)?;
 
     let current_module = ctx.sema.scope(record_field.syntax()).module()?;
-    let visibility = record_field_def.visibility(ctx.db);
-    if visibility.is_visible_from(ctx.db, current_module.into()) {
+    let visibility = record_field_def.visibility(ctx.db());
+    if visibility.is_visible_from(ctx.db(), current_module.into()) {
         return None;
     }
 
-    let parent = record_field_def.parent_def(ctx.db);
-    let parent_name = parent.name(ctx.db);
-    let target_module = parent.module(ctx.db);
+    let parent = record_field_def.parent_def(ctx.db());
+    let parent_name = parent.name(ctx.db());
+    let target_module = parent.module(ctx.db());
 
-    let in_file_source = record_field_def.source(ctx.db);
+    let in_file_source = record_field_def.source(ctx.db());
     let (offset, target) = match in_file_source.value {
         hir::FieldSource::Named(it) => {
             let s = it.syntax();
@@ -99,14 +95,14 @@ fn add_vis_to_referenced_record_field(acc: &mut Assists, ctx: &AssistContext) ->
 
     let missing_visibility =
         if current_module.krate() == target_module.krate() { "pub(crate)" } else { "pub" };
-    let target_file = in_file_source.file_id.original_file(ctx.db);
+    let target_file = in_file_source.file_id.original_file(ctx.db());
 
-    let target_name = record_field_def.name(ctx.db);
+    let target_name = record_field_def.name(ctx.db());
     let assist_label =
         format!("Change visibility of {}.{} to {}", parent_name, target_name, missing_visibility);
 
-    acc.add(AssistId("fix_visibility"), assist_label, target, |builder| {
-        builder.set_file(target_file);
+    acc.add(AssistId("fix_visibility", AssistKind::QuickFix), assist_label, target, |builder| {
+        builder.edit_file(target_file);
         match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, offset, format!("$0{} ", missing_visibility)),
             None => builder.insert(offset, format!("{} ", missing_visibility)),
@@ -177,17 +173,6 @@ fn target_data_for_def(
     Some((offset, target, target_file, target_name))
 }
 
-fn vis_offset(node: &SyntaxNode) -> TextSize {
-    node.children_with_tokens()
-        .skip_while(|it| match it.kind() {
-            WHITESPACE | COMMENT | ATTR => true,
-            _ => false,
-        })
-        .next()
-        .map(|it| it.text_range().start())
-        .unwrap_or_else(|| node.text_range().start())
-}
-
 #[cfg(test)]
 mod tests {
     use crate::tests::{check_assist, check_assist_not_applicable};
@@ -255,15 +240,14 @@ mod tests {
         check_assist(
             fix_visibility,
             r"
-              //- /main.rs
-              mod foo;
-              fn main() { foo::Foo<|> }
+//- /main.rs
+mod foo;
+fn main() { foo::Foo<|> }
 
-              //- /foo.rs
-              struct Foo;
-              ",
+//- /foo.rs
+struct Foo;
+",
             r"$0pub(crate) struct Foo;
-
 ",
         );
     }
@@ -279,14 +263,14 @@ mod tests {
         );
         check_assist(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo { <|>bar: () }; }
-              //- /foo.rs
-              pub struct Foo { bar: () }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo { <|>bar: () }; }
+//- /foo.rs
+pub struct Foo { bar: () }
+",
             r"pub struct Foo { $0pub(crate) bar: () }
-
 ",
         );
         check_assist_not_applicable(
@@ -296,12 +280,13 @@ mod tests {
         );
         check_assist_not_applicable(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo { <|>bar: () }; }
-              //- /foo.rs
-              pub struct Foo { pub bar: () }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo { <|>bar: () }; }
+//- /foo.rs
+pub struct Foo { pub bar: () }
+",
         );
     }
 
@@ -316,14 +301,14 @@ mod tests {
         );
         check_assist(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo::Bar { <|>bar: () }; }
-              //- /foo.rs
-              pub enum Foo { Bar { bar: () } }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo::Bar { <|>bar: () }; }
+//- /foo.rs
+pub enum Foo { Bar { bar: () } }
+",
             r"pub enum Foo { Bar { $0pub(crate) bar: () } }
-
 ",
         );
         check_assist_not_applicable(
@@ -333,12 +318,13 @@ mod tests {
         );
         check_assist_not_applicable(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo { <|>bar: () }; }
-              //- /foo.rs
-              pub struct Foo { pub bar: () }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo { <|>bar: () }; }
+//- /foo.rs
+pub struct Foo { pub bar: () }
+",
         );
     }
 
@@ -355,14 +341,14 @@ mod tests {
         );
         check_assist(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo { <|>bar: () }; }
-              //- /foo.rs
-              pub union Foo { bar: () }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo { <|>bar: () }; }
+//- /foo.rs
+pub union Foo { bar: () }
+",
             r"pub union Foo { $0pub(crate) bar: () }
-
 ",
         );
         check_assist_not_applicable(
@@ -372,12 +358,13 @@ mod tests {
         );
         check_assist_not_applicable(
             fix_visibility,
-            r"//- /lib.rs
-              mod foo;
-              fn main() { foo::Foo { <|>bar: () }; }
-              //- /foo.rs
-              pub union Foo { pub bar: () }
-              ",
+            r"
+//- /lib.rs
+mod foo;
+fn main() { foo::Foo { <|>bar: () }; }
+//- /foo.rs
+pub union Foo { pub bar: () }
+",
         );
     }
 
@@ -458,19 +445,18 @@ mod tests {
         check_assist(
             fix_visibility,
             r"
-            //- /main.rs
-            mod foo;
-            fn main() { foo::bar<|>::baz(); }
+//- /main.rs
+mod foo;
+fn main() { foo::bar<|>::baz(); }
 
-            //- /foo.rs
-            mod bar {
-                pub fn baz() {}
-            }
-            ",
+//- /foo.rs
+mod bar {
+    pub fn baz() {}
+}
+",
             r"$0pub(crate) mod bar {
     pub fn baz() {}
 }
-
 ",
         );
 
@@ -486,17 +472,15 @@ mod tests {
         check_assist(
             fix_visibility,
             r"
-            //- /main.rs
-            mod foo;
-            fn main() { foo::bar<|>::baz(); }
-
-            //- /foo.rs
-            mod bar;
-
-            //- /foo/bar.rs
-            pub fn baz() {}
-            }
-            ",
+//- /main.rs
+mod foo;
+fn main() { foo::bar<|>::baz(); }
+
+//- /foo.rs
+mod bar;
+//- /foo/bar.rs
+pub fn baz() {}
+",
             r"$0pub(crate) mod bar;
 ",
         );
@@ -506,14 +490,16 @@ mod tests {
     fn fix_visibility_of_module_declaration_in_other_file() {
         check_assist(
             fix_visibility,
-            r"//- /main.rs
-              mod foo;
-              fn main() { foo::bar<|>>::baz(); }
+            r"
+//- /main.rs
+mod foo;
+fn main() { foo::bar<|>>::baz(); }
 
-              //- /foo.rs
-              mod bar {
-                  pub fn baz() {}
-              }",
+//- /foo.rs
+mod bar {
+    pub fn baz() {}
+}
+",
             r"$0pub(crate) mod bar {
     pub fn baz() {}
 }
@@ -525,10 +511,12 @@ mod tests {
     fn adds_pub_when_target_is_in_another_crate() {
         check_assist(
             fix_visibility,
-            r"//- /main.rs crate:a deps:foo
-              foo::Bar<|>
-              //- /lib.rs crate:foo
-              struct Bar;",
+            r"
+//- /main.rs crate:a deps:foo
+foo::Bar<|>
+//- /lib.rs crate:foo
+struct Bar;
+",
             r"$0pub struct Bar;
 ",
         )
diff --git a/crates/ra_assists/src/handlers/flip_binexpr.rs b/crates/ra_assists/src/handlers/flip_binexpr.rs
index 573196576..3cd532650 100644
--- a/crates/ra_assists/src/handlers/flip_binexpr.rs
+++ b/crates/ra_assists/src/handlers/flip_binexpr.rs
@@ -1,6 +1,6 @@
 use ra_syntax::ast::{AstNode, BinExpr, BinOp};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: flip_binexpr
 //
@@ -33,13 +33,18 @@ pub(crate) fn flip_binexpr(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
         return None;
     }
 
-    acc.add(AssistId("flip_binexpr"), "Flip binary expression", op_range, |edit| {
-        if let FlipAction::FlipAndReplaceOp(new_op) = action {
-            edit.replace(op_range, new_op);
-        }
-        edit.replace(lhs.text_range(), rhs.text());
-        edit.replace(rhs.text_range(), lhs.text());
-    })
+    acc.add(
+        AssistId("flip_binexpr", AssistKind::RefactorRewrite),
+        "Flip binary expression",
+        op_range,
+        |edit| {
+            if let FlipAction::FlipAndReplaceOp(new_op) = action {
+                edit.replace(op_range, new_op);
+            }
+            edit.replace(lhs.text_range(), rhs.text());
+            edit.replace(rhs.text_range(), lhs.text());
+        },
+    )
 }
 
 enum FlipAction {
diff --git a/crates/ra_assists/src/handlers/flip_comma.rs b/crates/ra_assists/src/handlers/flip_comma.rs
index a57a1c463..55a971dc7 100644
--- a/crates/ra_assists/src/handlers/flip_comma.rs
+++ b/crates/ra_assists/src/handlers/flip_comma.rs
@@ -1,6 +1,6 @@
 use ra_syntax::{algo::non_trivia_sibling, Direction, T};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: flip_comma
 //
@@ -28,10 +28,15 @@ pub(crate) fn flip_comma(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
         return None;
     }
 
-    acc.add(AssistId("flip_comma"), "Flip comma", comma.text_range(), |edit| {
-        edit.replace(prev.text_range(), next.to_string());
-        edit.replace(next.text_range(), prev.to_string());
-    })
+    acc.add(
+        AssistId("flip_comma", AssistKind::RefactorRewrite),
+        "Flip comma",
+        comma.text_range(),
+        |edit| {
+            edit.replace(prev.text_range(), next.to_string());
+            edit.replace(next.text_range(), prev.to_string());
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/flip_trait_bound.rs b/crates/ra_assists/src/handlers/flip_trait_bound.rs
index 0115adc8b..1234f4d29 100644
--- a/crates/ra_assists/src/handlers/flip_trait_bound.rs
+++ b/crates/ra_assists/src/handlers/flip_trait_bound.rs
@@ -4,7 +4,7 @@ use ra_syntax::{
     Direction, T,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: flip_trait_bound
 //
@@ -33,10 +33,15 @@ pub(crate) fn flip_trait_bound(acc: &mut Assists, ctx: &AssistContext) -> Option
     );
 
     let target = plus.text_range();
-    acc.add(AssistId("flip_trait_bound"), "Flip trait bounds", target, |edit| {
-        edit.replace(before.text_range(), after.to_string());
-        edit.replace(after.text_range(), before.to_string());
-    })
+    acc.add(
+        AssistId("flip_trait_bound", AssistKind::RefactorRewrite),
+        "Flip trait bounds",
+        target,
+        |edit| {
+            edit.replace(before.text_range(), after.to_string());
+            edit.replace(after.text_range(), before.to_string());
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/add_derive.rs b/crates/ra_assists/src/handlers/generate_derive.rs
index b123b8498..6ccf39900 100644
--- a/crates/ra_assists/src/handlers/add_derive.rs
+++ b/crates/ra_assists/src/handlers/generate_derive.rs
@@ -4,9 +4,9 @@ use ra_syntax::{
     TextSize,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: add_derive
+// Assist: generate_derive
 //
 // Adds a new `#[derive()]` clause to a struct or enum.
 //
@@ -24,32 +24,37 @@ use crate::{AssistContext, AssistId, Assists};
 //     y: u32,
 // }
 // ```
-pub(crate) fn add_derive(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn generate_derive(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let cap = ctx.config.snippet_cap?;
     let nominal = ctx.find_node_at_offset::<ast::NominalDef>()?;
     let node_start = derive_insertion_offset(&nominal)?;
     let target = nominal.syntax().text_range();
-    acc.add(AssistId("add_derive"), "Add `#[derive]`", target, |builder| {
-        let derive_attr = nominal
-            .attrs()
-            .filter_map(|x| x.as_simple_call())
-            .filter(|(name, _arg)| name == "derive")
-            .map(|(_name, arg)| arg)
-            .next();
-        match derive_attr {
-            None => {
-                builder.insert_snippet(cap, node_start, "#[derive($0)]\n");
-            }
-            Some(tt) => {
-                // Just move the cursor.
-                builder.insert_snippet(
-                    cap,
-                    tt.syntax().text_range().end() - TextSize::of(')'),
-                    "$0",
-                )
-            }
-        };
-    })
+    acc.add(
+        AssistId("generate_derive", AssistKind::Generate),
+        "Add `#[derive]`",
+        target,
+        |builder| {
+            let derive_attr = nominal
+                .attrs()
+                .filter_map(|x| x.as_simple_call())
+                .filter(|(name, _arg)| name == "derive")
+                .map(|(_name, arg)| arg)
+                .next();
+            match derive_attr {
+                None => {
+                    builder.insert_snippet(cap, node_start, "#[derive($0)]\n");
+                }
+                Some(tt) => {
+                    // Just move the cursor.
+                    builder.insert_snippet(
+                        cap,
+                        tt.syntax().text_range().end() - TextSize::of(')'),
+                        "$0",
+                    )
+                }
+            };
+        },
+    )
 }
 
 // Insert `derive` after doc comments.
@@ -70,12 +75,12 @@ mod tests {
     #[test]
     fn add_derive_new() {
         check_assist(
-            add_derive,
+            generate_derive,
             "struct Foo { a: i32, <|>}",
             "#[derive($0)]\nstruct Foo { a: i32, }",
         );
         check_assist(
-            add_derive,
+            generate_derive,
             "struct Foo { <|> a: i32, }",
             "#[derive($0)]\nstruct Foo {  a: i32, }",
         );
@@ -84,7 +89,7 @@ mod tests {
     #[test]
     fn add_derive_existing() {
         check_assist(
-            add_derive,
+            generate_derive,
             "#[derive(Clone)]\nstruct Foo { a: i32<|>, }",
             "#[derive(Clone$0)]\nstruct Foo { a: i32, }",
         );
@@ -93,7 +98,7 @@ mod tests {
     #[test]
     fn add_derive_new_with_doc_comment() {
         check_assist(
-            add_derive,
+            generate_derive,
             "
 /// `Foo` is a pretty important struct.
 /// It does stuff.
@@ -111,7 +116,7 @@ struct Foo { a: i32, }
     #[test]
     fn add_derive_target() {
         check_assist_target(
-            add_derive,
+            generate_derive,
             "
 struct SomeThingIrrelevant;
 /// `Foo` is a pretty important struct.
diff --git a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs b/crates/ra_assists/src/handlers/generate_from_impl_for_enum.rs
index 776bddf91..a347e3c2e 100644
--- a/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs
+++ b/crates/ra_assists/src/handlers/generate_from_impl_for_enum.rs
@@ -2,9 +2,9 @@ use ra_ide_db::RootDatabase;
 use ra_syntax::ast::{self, AstNode, NameOwner};
 use test_utils::mark;
 
-use crate::{utils::FamousDefs, AssistContext, AssistId, Assists};
+use crate::{utils::FamousDefs, AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: add_from_impl_for_enum
+// Assist: generate_from_impl_for_enum
 //
 // Adds a From impl for an enum variant with one tuple field.
 //
@@ -21,7 +21,7 @@ use crate::{utils::FamousDefs, AssistContext, AssistId, Assists};
 //     }
 // }
 // ```
-pub(crate) fn add_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn generate_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let variant = ctx.find_node_at_offset::<ast::EnumVariant>()?;
     let variant_name = variant.name()?;
     let enum_name = variant.parent_enum().name()?;
@@ -45,8 +45,8 @@ pub(crate) fn add_from_impl_for_enum(acc: &mut Assists, ctx: &AssistContext) ->
 
     let target = variant.syntax().text_range();
     acc.add(
-        AssistId("add_from_impl_for_enum"),
-        "Add From impl for this enum variant",
+        AssistId("generate_from_impl_for_enum", AssistKind::Generate),
+        "Generate `From` impl for this enum variant",
         target,
         |edit| {
             let start_offset = variant.parent_enum().syntax().text_range().end();
@@ -97,9 +97,9 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_add_from_impl_for_enum() {
+    fn test_generate_from_impl_for_enum() {
         check_assist(
-            add_from_impl_for_enum,
+            generate_from_impl_for_enum,
             "enum A { <|>One(u32) }",
             r#"enum A { One(u32) }
 
@@ -112,9 +112,9 @@ impl From<u32> for A {
     }
 
     #[test]
-    fn test_add_from_impl_for_enum_complicated_path() {
+    fn test_generate_from_impl_for_enum_complicated_path() {
         check_assist(
-            add_from_impl_for_enum,
+            generate_from_impl_for_enum,
             r#"enum A { <|>One(foo::bar::baz::Boo) }"#,
             r#"enum A { One(foo::bar::baz::Boo) }
 
@@ -128,8 +128,8 @@ impl From<foo::bar::baz::Boo> for A {
 
     fn check_not_applicable(ra_fixture: &str) {
         let fixture =
-            format!("//- main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
-        check_assist_not_applicable(add_from_impl_for_enum, &fixture)
+            format!("//- /main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
+        check_assist_not_applicable(generate_from_impl_for_enum, &fixture)
     }
 
     #[test]
@@ -166,7 +166,7 @@ impl From<u32> for A {
     #[test]
     fn test_add_from_impl_different_variant_impl_exists() {
         check_assist(
-            add_from_impl_for_enum,
+            generate_from_impl_for_enum,
             r#"enum A { <|>One(u32), Two(String), }
 
 impl From<String> for A {
diff --git a/crates/ra_assists/src/handlers/add_function.rs b/crates/ra_assists/src/handlers/generate_function.rs
index 24f931a85..b721b96bb 100644
--- a/crates/ra_assists/src/handlers/add_function.rs
+++ b/crates/ra_assists/src/handlers/generate_function.rs
@@ -13,10 +13,10 @@ use rustc_hash::{FxHashMap, FxHashSet};
 use crate::{
     assist_config::SnippetCap,
     utils::{render_snippet, Cursor},
-    AssistContext, AssistId, Assists,
+    AssistContext, AssistId, AssistKind, Assists,
 };
 
-// Assist: add_function
+// Assist: generate_function
 //
 // Adds a stub function with a signature matching the function under the cursor.
 //
@@ -41,7 +41,7 @@ use crate::{
 // }
 //
 // ```
-pub(crate) fn add_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn generate_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let path_expr: ast::PathExpr = ctx.find_node_at_offset()?;
     let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
     let path = path_expr.path()?;
@@ -62,15 +62,20 @@ pub(crate) fn add_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     let function_builder = FunctionBuilder::from_call(&ctx, &call, &path, target_module)?;
 
     let target = call.syntax().text_range();
-    acc.add(AssistId("add_function"), "Add function", target, |builder| {
-        let function_template = function_builder.render();
-        builder.set_file(function_template.file);
-        let new_fn = function_template.to_string(ctx.config.snippet_cap);
-        match ctx.config.snippet_cap {
-            Some(cap) => builder.insert_snippet(cap, function_template.insert_offset, new_fn),
-            None => builder.insert(function_template.insert_offset, new_fn),
-        }
-    })
+    acc.add(
+        AssistId("generate_function", AssistKind::Generate),
+        format!("Generate `{}` function", function_builder.fn_name),
+        target,
+        |builder| {
+            let function_template = function_builder.render();
+            builder.edit_file(function_template.file);
+            let new_fn = function_template.to_string(ctx.config.snippet_cap);
+            match ctx.config.snippet_cap {
+                Some(cap) => builder.insert_snippet(cap, function_template.insert_offset, new_fn),
+                None => builder.insert(function_template.insert_offset, new_fn),
+            }
+        },
+    )
 }
 
 struct FunctionTemplate {
@@ -117,7 +122,7 @@ impl FunctionBuilder {
         let mut file = ctx.frange.file_id;
         let target = match &target_module {
             Some(target_module) => {
-                let module_source = target_module.definition_source(ctx.db);
+                let module_source = target_module.definition_source(ctx.db());
                 let (in_file, target) = next_space_for_fn_in_module(ctx.sema.db, &module_source)?;
                 file = in_file;
                 target
@@ -269,7 +274,7 @@ fn fn_arg_type(
         return None;
     }
 
-    if let Ok(rendered) = ty.display_source_code(ctx.db, target_module.into()) {
+    if let Ok(rendered) = ty.display_source_code(ctx.db(), target_module.into()) {
         Some(rendered)
     } else {
         None
@@ -333,7 +338,7 @@ mod tests {
     #[test]
     fn add_function_with_no_args() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     bar<|>();
@@ -356,7 +361,7 @@ fn bar() {
         // This ensures that the function is correctly generated
         // in the next outer mod or file
         check_assist(
-            add_function,
+            generate_function,
             r"
 impl Foo {
     fn foo() {
@@ -382,7 +387,7 @@ fn bar() {
     fn add_function_directly_after_current_block() {
         // The new fn should not be created at the end of the file or module
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo1() {
     bar<|>();
@@ -407,7 +412,7 @@ fn foo2() {}
     #[test]
     fn add_function_with_no_args_in_same_module() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 mod baz {
     fn foo() {
@@ -432,7 +437,7 @@ mod baz {
     #[test]
     fn add_function_with_function_call_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Baz;
 fn baz() -> Baz { todo!() }
@@ -457,7 +462,7 @@ fn bar(baz: Baz) {
     #[test]
     fn add_function_with_method_call_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Baz;
 impl Baz {
@@ -490,7 +495,7 @@ fn bar(baz: Baz) {
     #[test]
     fn add_function_with_string_literal_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r#"
 fn foo() {
     <|>bar("bar")
@@ -511,7 +516,7 @@ fn bar(arg: &str) {
     #[test]
     fn add_function_with_char_literal_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r#"
 fn foo() {
     <|>bar('x')
@@ -532,7 +537,7 @@ fn bar(arg: char) {
     #[test]
     fn add_function_with_int_literal_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     <|>bar(42)
@@ -553,7 +558,7 @@ fn bar(arg: i32) {
     #[test]
     fn add_function_with_cast_int_literal_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     <|>bar(42 as u8)
@@ -576,7 +581,7 @@ fn bar(arg: u8) {
         // Ensures that the name of the cast type isn't used
         // in the generated function signature.
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     let x = 42;
@@ -599,7 +604,7 @@ fn bar(x: u8) {
     #[test]
     fn add_function_with_variable_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     let worble = ();
@@ -622,7 +627,7 @@ fn bar(worble: ()) {
     #[test]
     fn add_function_with_impl_trait_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 trait Foo {}
 fn foo() -> impl Foo {
@@ -651,7 +656,7 @@ fn bar(foo: impl Foo) {
     #[test]
     fn borrowed_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Baz;
 fn baz() -> Baz { todo!() }
@@ -678,7 +683,7 @@ fn bar(baz: &Baz) {
     #[test]
     fn add_function_with_qualified_path_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 mod Baz {
     pub struct Bof;
@@ -709,7 +714,7 @@ fn bar(baz: Baz::Bof) {
     // FIXME fix printing the generics of a `Ty` to make this test pass
     fn add_function_with_generic_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo<T>(t: T) {
     <|>bar(t)
@@ -732,7 +737,7 @@ fn bar<T>(t: T) {
     // FIXME Fix function type printing to make this test pass
     fn add_function_with_fn_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Baz;
 impl Baz {
@@ -763,7 +768,7 @@ fn bar(arg: fn() -> Baz) {
     // FIXME Fix closure type printing to make this test pass
     fn add_function_with_closure_arg() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     let closure = |x: i64| x - 1;
@@ -786,7 +791,7 @@ fn bar(closure: impl Fn(i64) -> i64) {
     #[test]
     fn unresolveable_types_default_to_unit() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     <|>bar(baz)
@@ -807,7 +812,7 @@ fn bar(baz: ()) {
     #[test]
     fn arg_names_dont_overlap() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Baz;
 fn baz() -> Baz { Baz }
@@ -832,7 +837,7 @@ fn bar(baz_1: Baz, baz_2: Baz) {
     #[test]
     fn arg_name_counters_start_at_1_per_name() {
         check_assist(
-            add_function,
+            generate_function,
             r#"
 struct Baz;
 fn baz() -> Baz { Baz }
@@ -857,7 +862,7 @@ fn bar(baz_1: Baz, baz_2: Baz, arg_1: &str, arg_2: &str) {
     #[test]
     fn add_function_in_module() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 mod bar {}
 
@@ -885,7 +890,7 @@ fn foo() {
     // See https://github.com/rust-analyzer/rust-analyzer/issues/1165
     fn qualified_path_uses_correct_scope() {
         check_assist(
-            add_function,
+            generate_function,
             "
 mod foo {
     pub struct Foo;
@@ -916,7 +921,7 @@ fn baz(foo: foo::Foo) {
     #[test]
     fn add_function_in_module_containing_other_items() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 mod bar {
     fn something_else() {}
@@ -945,7 +950,7 @@ fn foo() {
     #[test]
     fn add_function_in_nested_module() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 mod bar {
     mod baz {}
@@ -974,7 +979,7 @@ fn foo() {
     #[test]
     fn add_function_in_another_file() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 //- /main.rs
 mod foo;
@@ -996,7 +1001,7 @@ pub(crate) fn bar() {
     #[test]
     fn add_function_not_applicable_if_function_already_exists() {
         check_assist_not_applicable(
-            add_function,
+            generate_function,
             r"
 fn foo() {
     bar<|>();
@@ -1013,7 +1018,7 @@ fn bar() {}
             // bar is resolved, but baz isn't.
             // The assist is only active if the cursor is on an unresolved path,
             // but the assist should only be offered if the path is a function call.
-            add_function,
+            generate_function,
             r"
 fn foo() {
     bar(b<|>az);
@@ -1028,7 +1033,7 @@ fn bar(baz: ()) {}
     #[ignore]
     fn create_method_with_no_args() {
         check_assist(
-            add_function,
+            generate_function,
             r"
 struct Foo;
 impl Foo {
diff --git a/crates/ra_assists/src/handlers/generate_impl.rs b/crates/ra_assists/src/handlers/generate_impl.rs
new file mode 100644
index 000000000..cbbac1d7f
--- /dev/null
+++ b/crates/ra_assists/src/handlers/generate_impl.rs
@@ -0,0 +1,109 @@
+use ra_syntax::ast::{self, AstNode, NameOwner, TypeParamsOwner};
+use stdx::{format_to, SepBy};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: generate_impl
+//
+// Adds a new inherent impl for a type.
+//
+// ```
+// struct Ctx<T: Clone> {
+//     data: T,<|>
+// }
+// ```
+// ->
+// ```
+// struct Ctx<T: Clone> {
+//     data: T,
+// }
+//
+// impl<T: Clone> Ctx<T> {
+//     $0
+// }
+// ```
+pub(crate) fn generate_impl(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+    let nominal = ctx.find_node_at_offset::<ast::NominalDef>()?;
+    let name = nominal.name()?;
+    let target = nominal.syntax().text_range();
+    acc.add(
+        AssistId("generate_impl", AssistKind::Generate),
+        format!("Generate impl for `{}`", name),
+        target,
+        |edit| {
+            let type_params = nominal.type_param_list();
+            let start_offset = nominal.syntax().text_range().end();
+            let mut buf = String::new();
+            buf.push_str("\n\nimpl");
+            if let Some(type_params) = &type_params {
+                format_to!(buf, "{}", type_params.syntax());
+            }
+            buf.push_str(" ");
+            buf.push_str(name.text().as_str());
+            if let Some(type_params) = type_params {
+                let lifetime_params = type_params
+                    .lifetime_params()
+                    .filter_map(|it| it.lifetime_token())
+                    .map(|it| it.text().clone());
+                let type_params = type_params
+                    .type_params()
+                    .filter_map(|it| it.name())
+                    .map(|it| it.text().clone());
+
+                let generic_params = lifetime_params.chain(type_params).sep_by(", ");
+                format_to!(buf, "<{}>", generic_params)
+            }
+            match ctx.config.snippet_cap {
+                Some(cap) => {
+                    buf.push_str(" {\n    $0\n}");
+                    edit.insert_snippet(cap, start_offset, buf);
+                }
+                None => {
+                    buf.push_str(" {\n}");
+                    edit.insert(start_offset, buf);
+                }
+            }
+        },
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_target};
+
+    use super::*;
+
+    #[test]
+    fn test_add_impl() {
+        check_assist(
+            generate_impl,
+            "struct Foo {<|>}\n",
+            "struct Foo {}\n\nimpl Foo {\n    $0\n}\n",
+        );
+        check_assist(
+            generate_impl,
+            "struct Foo<T: Clone> {<|>}",
+            "struct Foo<T: Clone> {}\n\nimpl<T: Clone> Foo<T> {\n    $0\n}",
+        );
+        check_assist(
+            generate_impl,
+            "struct Foo<'a, T: Foo<'a>> {<|>}",
+            "struct Foo<'a, T: Foo<'a>> {}\n\nimpl<'a, T: Foo<'a>> Foo<'a, T> {\n    $0\n}",
+        );
+    }
+
+    #[test]
+    fn add_impl_target() {
+        check_assist_target(
+            generate_impl,
+            "
+struct SomeThingIrrelevant;
+/// Has a lifetime parameter
+struct Foo<'a, T: Foo<'a>> {<|>}
+struct EvenMoreIrrelevant;
+",
+            "/// Has a lifetime parameter
+struct Foo<'a, T: Foo<'a>> {}",
+        );
+    }
+}
diff --git a/crates/ra_assists/src/handlers/add_new.rs b/crates/ra_assists/src/handlers/generate_new.rs
index 837aa8377..e27def1d8 100644
--- a/crates/ra_assists/src/handlers/add_new.rs
+++ b/crates/ra_assists/src/handlers/generate_new.rs
@@ -7,9 +7,9 @@ use ra_syntax::{
 };
 use stdx::{format_to, SepBy};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: add_new
+// Assist: generate_new
 //
 // Adds a new inherent impl for a type.
 //
@@ -29,7 +29,7 @@ use crate::{AssistContext, AssistId, Assists};
 // }
 //
 // ```
-pub(crate) fn add_new(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn generate_new(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let strukt = ctx.find_node_at_offset::<ast::StructDef>()?;
 
     // We want to only apply this to non-union structs with named fields
@@ -42,7 +42,7 @@ pub(crate) fn add_new(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let impl_def = find_struct_impl(&ctx, &strukt)?;
 
     let target = strukt.syntax().text_range();
-    acc.add(AssistId("add_new"), "Add default constructor", target, |builder| {
+    acc.add(AssistId("generate_new", AssistKind::Generate), "Generate `new`", target, |builder| {
         let mut buf = String::with_capacity(512);
 
         if impl_def.is_some() {
@@ -122,7 +122,7 @@ fn generate_impl_text(strukt: &ast::StructDef, code: &str) -> String {
 // FIXME: change the new fn checking to a more semantic approach when that's more
 // viable (e.g. we process proc macros, etc)
 fn find_struct_impl(ctx: &AssistContext, strukt: &ast::StructDef) -> Option<Option<ast::ImplDef>> {
-    let db = ctx.db;
+    let db = ctx.db();
     let module = strukt.syntax().ancestors().find(|node| {
         ast::Module::can_cast(node.kind()) || ast::SourceFile::can_cast(node.kind())
     })?;
@@ -181,10 +181,10 @@ mod tests {
 
     #[test]
     #[rustfmt::skip]
-    fn test_add_new() {
+    fn test_generate_new() {
         // Check output of generation
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo {<|>}",
 "struct Foo {}
 
@@ -194,7 +194,7 @@ impl Foo {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo<T: Clone> {<|>}",
 "struct Foo<T: Clone> {}
 
@@ -204,7 +204,7 @@ impl<T: Clone> Foo<T> {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo<'a, T: Foo<'a>> {<|>}",
 "struct Foo<'a, T: Foo<'a>> {}
 
@@ -214,7 +214,7 @@ impl<'a, T: Foo<'a>> Foo<'a, T> {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo { baz: String <|>}",
 "struct Foo { baz: String }
 
@@ -224,7 +224,7 @@ impl Foo {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo { baz: String, qux: Vec<i32> <|>}",
 "struct Foo { baz: String, qux: Vec<i32> }
 
@@ -236,7 +236,7 @@ impl Foo {
 
         // Check that visibility modifiers don't get brought in for fields
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo { pub baz: String, pub qux: Vec<i32> <|>}",
 "struct Foo { pub baz: String, pub qux: Vec<i32> }
 
@@ -248,7 +248,7 @@ impl Foo {
 
         // Check that it reuses existing impls
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo {<|>}
 
 impl Foo {}
@@ -261,7 +261,7 @@ impl Foo {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo {<|>}
 
 impl Foo {
@@ -279,7 +279,7 @@ impl Foo {
         );
 
         check_assist(
-            add_new,
+            generate_new,
 "struct Foo {<|>}
 
 impl Foo {
@@ -304,7 +304,7 @@ impl Foo {
 
         // Check visibility of new fn based on struct
         check_assist(
-            add_new,
+            generate_new,
 "pub struct Foo {<|>}",
 "pub struct Foo {}
 
@@ -314,7 +314,7 @@ impl Foo {
 ",
         );
         check_assist(
-            add_new,
+            generate_new,
 "pub(crate) struct Foo {<|>}",
 "pub(crate) struct Foo {}
 
@@ -326,9 +326,9 @@ impl Foo {
     }
 
     #[test]
-    fn add_new_not_applicable_if_fn_exists() {
+    fn generate_new_not_applicable_if_fn_exists() {
         check_assist_not_applicable(
-            add_new,
+            generate_new,
             "
 struct Foo {<|>}
 
@@ -340,7 +340,7 @@ impl Foo {
         );
 
         check_assist_not_applicable(
-            add_new,
+            generate_new,
             "
 struct Foo {<|>}
 
@@ -353,9 +353,9 @@ impl Foo {
     }
 
     #[test]
-    fn add_new_target() {
+    fn generate_new_target() {
         check_assist_target(
-            add_new,
+            generate_new,
             "
 struct SomeThingIrrelevant;
 /// Has a lifetime parameter
@@ -370,7 +370,7 @@ struct Foo<'a, T: Foo<'a>> {}",
     #[test]
     fn test_unrelated_new() {
         check_assist(
-            add_new,
+            generate_new,
             r##"
 pub struct AstId<N: AstNode> {
     file_id: HirFileId,
diff --git a/crates/ra_assists/src/handlers/inline_local_variable.rs b/crates/ra_assists/src/handlers/inline_local_variable.rs
index d26e68847..2fdfabaf5 100644
--- a/crates/ra_assists/src/handlers/inline_local_variable.rs
+++ b/crates/ra_assists/src/handlers/inline_local_variable.rs
@@ -7,7 +7,7 @@ use test_utils::mark;
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: inline_local_variable
@@ -44,7 +44,7 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
 
     let def = ctx.sema.to_def(&bind_pat)?;
     let def = Definition::Local(def);
-    let refs = def.find_usages(ctx.db, None);
+    let refs = def.find_usages(&ctx.sema, None);
     if refs.is_empty() {
         mark::hit!(test_not_applicable_if_variable_unused);
         return None;
@@ -110,13 +110,19 @@ pub(crate) fn inline_local_variable(acc: &mut Assists, ctx: &AssistContext) -> O
     let init_in_paren = format!("({})", &init_str);
 
     let target = bind_pat.syntax().text_range();
-    acc.add(AssistId("inline_local_variable"), "Inline variable", target, move |builder| {
-        builder.delete(delete_range);
-        for (desc, should_wrap) in refs.iter().zip(wrap_in_parens) {
-            let replacement = if should_wrap { init_in_paren.clone() } else { init_str.clone() };
-            builder.replace(desc.file_range.range, replacement)
-        }
-    })
+    acc.add(
+        AssistId("inline_local_variable", AssistKind::RefactorInline),
+        "Inline variable",
+        target,
+        move |builder| {
+            builder.delete(delete_range);
+            for (desc, should_wrap) in refs.iter().zip(wrap_in_parens) {
+                let replacement =
+                    if should_wrap { init_in_paren.clone() } else { init_str.clone() };
+                builder.replace(desc.file_range.range, replacement)
+            }
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/change_lifetime_anon_to_named.rs b/crates/ra_assists/src/handlers/introduce_named_lifetime.rs
index 999aec421..967593031 100644
--- a/crates/ra_assists/src/handlers/change_lifetime_anon_to_named.rs
+++ b/crates/ra_assists/src/handlers/introduce_named_lifetime.rs
@@ -1,12 +1,15 @@
-use crate::{assist_context::AssistBuilder, AssistContext, AssistId, Assists};
-use ast::{NameOwner, ParamList, TypeAscriptionOwner, TypeParamList, TypeRef};
-use ra_syntax::{ast, ast::TypeParamsOwner, AstNode, SyntaxKind, TextRange, TextSize};
+use ra_syntax::{
+    ast::{self, NameOwner, TypeAscriptionOwner, TypeParamsOwner},
+    AstNode, SyntaxKind, TextRange, TextSize,
+};
 use rustc_hash::FxHashSet;
 
-static ASSIST_NAME: &str = "change_lifetime_anon_to_named";
-static ASSIST_LABEL: &str = "Give anonymous lifetime a name";
+use crate::{assist_context::AssistBuilder, AssistContext, AssistId, AssistKind, Assists};
 
-// Assist: change_lifetime_anon_to_named
+static ASSIST_NAME: &str = "introduce_named_lifetime";
+static ASSIST_LABEL: &str = "Introduce named lifetime";
+
+// Assist: introduce_named_lifetime
 //
 // Change an anonymous lifetime to a named lifetime.
 //
@@ -31,15 +34,13 @@ static ASSIST_LABEL: &str = "Give anonymous lifetime a name";
 // ```
 // FIXME: How can we handle renaming any one of multiple anonymous lifetimes?
 // FIXME: should also add support for the case fun(f: &Foo) -> &<|>Foo
-pub(crate) fn change_lifetime_anon_to_named(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+pub(crate) fn introduce_named_lifetime(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let lifetime_token = ctx
         .find_token_at_offset(SyntaxKind::LIFETIME)
         .filter(|lifetime| lifetime.text() == "'_")?;
     if let Some(fn_def) = lifetime_token.ancestors().find_map(ast::FnDef::cast) {
         generate_fn_def_assist(acc, &fn_def, lifetime_token.text_range())
     } else if let Some(impl_def) = lifetime_token.ancestors().find_map(ast::ImplDef::cast) {
-        // only allow naming the last anonymous lifetime
-        lifetime_token.next_token().filter(|tok| tok.kind() == SyntaxKind::R_ANGLE)?;
         generate_impl_def_assist(acc, &impl_def, lifetime_token.text_range())
     } else {
         None
@@ -52,7 +53,7 @@ fn generate_fn_def_assist(
     fn_def: &ast::FnDef,
     lifetime_loc: TextRange,
 ) -> Option<()> {
-    let param_list: ParamList = fn_def.param_list()?;
+    let param_list: ast::ParamList = fn_def.param_list()?;
     let new_lifetime_param = generate_unique_lifetime_param_name(&fn_def.type_param_list())?;
     let end_of_fn_ident = fn_def.name()?.ident_token()?.text_range().end();
     let self_param =
@@ -67,7 +68,7 @@ fn generate_fn_def_assist(
         let fn_params_without_lifetime: Vec<_> = param_list
             .params()
             .filter_map(|param| match param.ascribed_type() {
-                Some(TypeRef::ReferenceType(ascribed_type))
+                Some(ast::TypeRef::ReferenceType(ascribed_type))
                     if ascribed_type.lifetime_token() == None =>
                 {
                     Some(ascribed_type.amp_token()?.text_range().end())
@@ -82,7 +83,7 @@ fn generate_fn_def_assist(
             _ => return None,
         }
     };
-    acc.add(AssistId(ASSIST_NAME), ASSIST_LABEL, lifetime_loc, |builder| {
+    acc.add(AssistId(ASSIST_NAME, AssistKind::Refactor), ASSIST_LABEL, lifetime_loc, |builder| {
         add_lifetime_param(fn_def, builder, end_of_fn_ident, new_lifetime_param);
         builder.replace(lifetime_loc, format!("'{}", new_lifetime_param));
         loc_needing_lifetime.map(|loc| builder.insert(loc, format!("'{} ", new_lifetime_param)));
@@ -97,7 +98,7 @@ fn generate_impl_def_assist(
 ) -> Option<()> {
     let new_lifetime_param = generate_unique_lifetime_param_name(&impl_def.type_param_list())?;
     let end_of_impl_kw = impl_def.impl_token()?.text_range().end();
-    acc.add(AssistId(ASSIST_NAME), ASSIST_LABEL, lifetime_loc, |builder| {
+    acc.add(AssistId(ASSIST_NAME, AssistKind::Refactor), ASSIST_LABEL, lifetime_loc, |builder| {
         add_lifetime_param(impl_def, builder, end_of_impl_kw, new_lifetime_param);
         builder.replace(lifetime_loc, format!("'{}", new_lifetime_param));
     })
@@ -106,7 +107,7 @@ fn generate_impl_def_assist(
 /// Given a type parameter list, generate a unique lifetime parameter name
 /// which is not in the list
 fn generate_unique_lifetime_param_name(
-    existing_type_param_list: &Option<TypeParamList>,
+    existing_type_param_list: &Option<ast::TypeParamList>,
 ) -> Option<char> {
     match existing_type_param_list {
         Some(type_params) => {
@@ -151,7 +152,7 @@ mod tests {
     #[test]
     fn test_example_case() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl Cursor<'_<|>> {
                 fn node(self) -> &SyntaxNode {
                     match self {
@@ -172,7 +173,7 @@ mod tests {
     #[test]
     fn test_example_case_simplified() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl Cursor<'_<|>> {"#,
             r#"impl<'a> Cursor<'a> {"#,
         );
@@ -181,16 +182,33 @@ mod tests {
     #[test]
     fn test_example_case_cursor_after_tick() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl Cursor<'<|>_> {"#,
             r#"impl<'a> Cursor<'a> {"#,
         );
     }
 
     #[test]
+    fn test_impl_with_other_type_param() {
+        check_assist(
+            introduce_named_lifetime,
+            "impl<I> fmt::Display for SepByBuilder<'_<|>, I>
+        where
+            I: Iterator,
+            I::Item: fmt::Display,
+        {",
+            "impl<I, 'a> fmt::Display for SepByBuilder<'a, I>
+        where
+            I: Iterator,
+            I::Item: fmt::Display,
+        {",
+        )
+    }
+
+    #[test]
     fn test_example_case_cursor_before_tick() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl Cursor<<|>'_> {"#,
             r#"impl<'a> Cursor<'a> {"#,
         );
@@ -198,23 +216,20 @@ mod tests {
 
     #[test]
     fn test_not_applicable_cursor_position() {
-        check_assist_not_applicable(change_lifetime_anon_to_named, r#"impl Cursor<'_><|> {"#);
-        check_assist_not_applicable(change_lifetime_anon_to_named, r#"impl Cursor<|><'_> {"#);
+        check_assist_not_applicable(introduce_named_lifetime, r#"impl Cursor<'_><|> {"#);
+        check_assist_not_applicable(introduce_named_lifetime, r#"impl Cursor<|><'_> {"#);
     }
 
     #[test]
     fn test_not_applicable_lifetime_already_name() {
-        check_assist_not_applicable(change_lifetime_anon_to_named, r#"impl Cursor<'a<|>> {"#);
-        check_assist_not_applicable(
-            change_lifetime_anon_to_named,
-            r#"fn my_fun<'a>() -> X<'a<|>>"#,
-        );
+        check_assist_not_applicable(introduce_named_lifetime, r#"impl Cursor<'a<|>> {"#);
+        check_assist_not_applicable(introduce_named_lifetime, r#"fn my_fun<'a>() -> X<'a<|>>"#);
     }
 
     #[test]
     fn test_with_type_parameter() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl<T> Cursor<T, '_<|>>"#,
             r#"impl<T, 'a> Cursor<T, 'a>"#,
         );
@@ -223,7 +238,7 @@ mod tests {
     #[test]
     fn test_with_existing_lifetime_name_conflict() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"impl<'a, 'b> Cursor<'a, 'b, '_<|>>"#,
             r#"impl<'a, 'b, 'c> Cursor<'a, 'b, 'c>"#,
         );
@@ -232,7 +247,7 @@ mod tests {
     #[test]
     fn test_function_return_value_anon_lifetime_param() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun() -> X<'_<|>>"#,
             r#"fn my_fun<'a>() -> X<'a>"#,
         );
@@ -241,7 +256,7 @@ mod tests {
     #[test]
     fn test_function_return_value_anon_reference_lifetime() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun() -> &'_<|> X"#,
             r#"fn my_fun<'a>() -> &'a X"#,
         );
@@ -250,7 +265,7 @@ mod tests {
     #[test]
     fn test_function_param_anon_lifetime() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun(x: X<'_<|>>)"#,
             r#"fn my_fun<'a>(x: X<'a>)"#,
         );
@@ -259,7 +274,7 @@ mod tests {
     #[test]
     fn test_function_add_lifetime_to_params() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun(f: &Foo) -> X<'_<|>>"#,
             r#"fn my_fun<'a>(f: &'a Foo) -> X<'a>"#,
         );
@@ -268,7 +283,7 @@ mod tests {
     #[test]
     fn test_function_add_lifetime_to_params_in_presence_of_other_lifetime() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun<'other>(f: &Foo, b: &'other Bar) -> X<'_<|>>"#,
             r#"fn my_fun<'other, 'a>(f: &'a Foo, b: &'other Bar) -> X<'a>"#,
         );
@@ -278,7 +293,7 @@ mod tests {
     fn test_function_not_applicable_without_self_and_multiple_unnamed_param_lifetimes() {
         // this is not permitted under lifetime elision rules
         check_assist_not_applicable(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun(f: &Foo, b: &Bar) -> X<'_<|>>"#,
         );
     }
@@ -286,7 +301,7 @@ mod tests {
     #[test]
     fn test_function_add_lifetime_to_self_ref_param() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun<'other>(&self, f: &Foo, b: &'other Bar) -> X<'_<|>>"#,
             r#"fn my_fun<'other, 'a>(&'a self, f: &Foo, b: &'other Bar) -> X<'a>"#,
         );
@@ -295,7 +310,7 @@ mod tests {
     #[test]
     fn test_function_add_lifetime_to_param_with_non_ref_self() {
         check_assist(
-            change_lifetime_anon_to_named,
+            introduce_named_lifetime,
             r#"fn my_fun<'other>(self, f: &Foo, b: &'other Bar) -> X<'_<|>>"#,
             r#"fn my_fun<'other, 'a>(self, f: &'a Foo, b: &'other Bar) -> X<'a>"#,
         );
diff --git a/crates/ra_assists/src/handlers/invert_if.rs b/crates/ra_assists/src/handlers/invert_if.rs
index 59d278eb9..bbe3f3643 100644
--- a/crates/ra_assists/src/handlers/invert_if.rs
+++ b/crates/ra_assists/src/handlers/invert_if.rs
@@ -6,7 +6,7 @@ use ra_syntax::{
 use crate::{
     assist_context::{AssistContext, Assists},
     utils::invert_boolean_expression,
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: invert_if
@@ -54,7 +54,7 @@ pub(crate) fn invert_if(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let else_node = else_block.syntax();
     let else_range = else_node.text_range();
     let then_range = then_node.text_range();
-    acc.add(AssistId("invert_if"), "Invert if", if_range, |edit| {
+    acc.add(AssistId("invert_if", AssistKind::RefactorRewrite), "Invert if", if_range, |edit| {
         edit.replace(cond_range, flip_cond.syntax().text());
         edit.replace(else_range, then_node.text());
         edit.replace(then_range, else_node.text());
diff --git a/crates/ra_assists/src/handlers/merge_imports.rs b/crates/ra_assists/src/handlers/merge_imports.rs
index 972d16241..1beccb61c 100644
--- a/crates/ra_assists/src/handlers/merge_imports.rs
+++ b/crates/ra_assists/src/handlers/merge_imports.rs
@@ -8,7 +8,7 @@ use ra_syntax::{
 
 use crate::{
     assist_context::{AssistContext, Assists},
-    AssistId,
+    AssistId, AssistKind,
 };
 
 // Assist: merge_imports
@@ -56,9 +56,14 @@ pub(crate) fn merge_imports(acc: &mut Assists, ctx: &AssistContext) -> Option<()
     };
 
     let target = tree.syntax().text_range();
-    acc.add(AssistId("merge_imports"), "Merge imports", target, |builder| {
-        builder.rewrite(rewriter);
-    })
+    acc.add(
+        AssistId("merge_imports", AssistKind::RefactorRewrite),
+        "Merge imports",
+        target,
+        |builder| {
+            builder.rewrite(rewriter);
+        },
+    )
 }
 
 fn next_prev() -> impl Iterator<Item = Direction> {
@@ -127,7 +132,7 @@ fn first_path(path: &ast::Path) -> ast::Path {
 
 #[cfg(test)]
 mod tests {
-    use crate::tests::check_assist;
+    use crate::tests::{check_assist, check_assist_not_applicable};
 
     use super::*;
 
@@ -276,4 +281,14 @@ bar::baz};
 ",
         )
     }
+
+    #[test]
+    fn test_empty_use() {
+        check_assist_not_applicable(
+            merge_imports,
+            r"
+use std::<|>
+fn main() {}",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/merge_match_arms.rs b/crates/ra_assists/src/handlers/merge_match_arms.rs
index ca04ec671..186a1f618 100644
--- a/crates/ra_assists/src/handlers/merge_match_arms.rs
+++ b/crates/ra_assists/src/handlers/merge_match_arms.rs
@@ -6,7 +6,7 @@ use ra_syntax::{
     Direction,
 };
 
-use crate::{AssistContext, AssistId, Assists, TextRange};
+use crate::{AssistContext, AssistId, AssistKind, Assists, TextRange};
 
 // Assist: merge_match_arms
 //
@@ -59,32 +59,34 @@ pub(crate) fn merge_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option
         return None;
     }
 
-    acc.add(AssistId("merge_match_arms"), "Merge match arms", current_text_range, |edit| {
-        let pats = if arms_to_merge.iter().any(contains_placeholder) {
-            "_".into()
-        } else {
-            arms_to_merge
-                .iter()
-                .filter_map(ast::MatchArm::pat)
-                .map(|x| x.syntax().to_string())
-                .collect::<Vec<String>>()
-                .join(" | ")
-        };
-
-        let arm = format!("{} => {}", pats, current_expr.syntax().text());
-
-        let start = arms_to_merge.first().unwrap().syntax().text_range().start();
-        let end = arms_to_merge.last().unwrap().syntax().text_range().end();
-
-        edit.replace(TextRange::new(start, end), arm);
-    })
+    acc.add(
+        AssistId("merge_match_arms", AssistKind::RefactorRewrite),
+        "Merge match arms",
+        current_text_range,
+        |edit| {
+            let pats = if arms_to_merge.iter().any(contains_placeholder) {
+                "_".into()
+            } else {
+                arms_to_merge
+                    .iter()
+                    .filter_map(ast::MatchArm::pat)
+                    .map(|x| x.syntax().to_string())
+                    .collect::<Vec<String>>()
+                    .join(" | ")
+            };
+
+            let arm = format!("{} => {}", pats, current_expr.syntax().text());
+
+            let start = arms_to_merge.first().unwrap().syntax().text_range().start();
+            let end = arms_to_merge.last().unwrap().syntax().text_range().end();
+
+            edit.replace(TextRange::new(start, end), arm);
+        },
+    )
 }
 
 fn contains_placeholder(a: &ast::MatchArm) -> bool {
-    match a.pat() {
-        Some(ra_syntax::ast::Pat::PlaceholderPat(..)) => true,
-        _ => false,
-    }
+    matches!(a.pat(), Some(ast::Pat::PlaceholderPat(..)))
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/move_bounds.rs b/crates/ra_assists/src/handlers/move_bounds.rs
index be2a7eddc..ba3dafb99 100644
--- a/crates/ra_assists/src/handlers/move_bounds.rs
+++ b/crates/ra_assists/src/handlers/move_bounds.rs
@@ -5,7 +5,7 @@ use ra_syntax::{
     T,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: move_bounds_to_where_clause
 //
@@ -50,29 +50,36 @@ pub(crate) fn move_bounds_to_where_clause(acc: &mut Assists, ctx: &AssistContext
     };
 
     let target = type_param_list.syntax().text_range();
-    acc.add(AssistId("move_bounds_to_where_clause"), "Move to where clause", target, |edit| {
-        let new_params = type_param_list
-            .type_params()
-            .filter(|it| it.type_bound_list().is_some())
-            .map(|type_param| {
-                let without_bounds = type_param.remove_bounds();
-                (type_param, without_bounds)
-            });
-
-        let new_type_param_list = type_param_list.replace_descendants(new_params);
-        edit.replace_ast(type_param_list.clone(), new_type_param_list);
-
-        let where_clause = {
-            let predicates = type_param_list.type_params().filter_map(build_predicate);
-            make::where_clause(predicates)
-        };
-
-        let to_insert = match anchor.prev_sibling_or_token() {
-            Some(ref elem) if elem.kind() == WHITESPACE => format!("{} ", where_clause.syntax()),
-            _ => format!(" {}", where_clause.syntax()),
-        };
-        edit.insert(anchor.text_range().start(), to_insert);
-    })
+    acc.add(
+        AssistId("move_bounds_to_where_clause", AssistKind::RefactorRewrite),
+        "Move to where clause",
+        target,
+        |edit| {
+            let new_params = type_param_list
+                .type_params()
+                .filter(|it| it.type_bound_list().is_some())
+                .map(|type_param| {
+                    let without_bounds = type_param.remove_bounds();
+                    (type_param, without_bounds)
+                });
+
+            let new_type_param_list = type_param_list.replace_descendants(new_params);
+            edit.replace_ast(type_param_list.clone(), new_type_param_list);
+
+            let where_clause = {
+                let predicates = type_param_list.type_params().filter_map(build_predicate);
+                make::where_clause(predicates)
+            };
+
+            let to_insert = match anchor.prev_sibling_or_token() {
+                Some(ref elem) if elem.kind() == WHITESPACE => {
+                    format!("{} ", where_clause.syntax())
+                }
+                _ => format!(" {}", where_clause.syntax()),
+            };
+            edit.insert(anchor.text_range().start(), to_insert);
+        },
+    )
 }
 
 fn build_predicate(param: ast::TypeParam) -> Option<ast::WherePred> {
diff --git a/crates/ra_assists/src/handlers/move_guard.rs b/crates/ra_assists/src/handlers/move_guard.rs
index 7edcf0748..4060d34c6 100644
--- a/crates/ra_assists/src/handlers/move_guard.rs
+++ b/crates/ra_assists/src/handlers/move_guard.rs
@@ -3,7 +3,7 @@ use ra_syntax::{
     SyntaxKind::WHITESPACE,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: move_guard_to_arm_body
 //
@@ -40,17 +40,22 @@ pub(crate) fn move_guard_to_arm_body(acc: &mut Assists, ctx: &AssistContext) ->
     let buf = format!("if {} {{ {} }}", guard_conditions.syntax().text(), arm_expr.syntax().text());
 
     let target = guard.syntax().text_range();
-    acc.add(AssistId("move_guard_to_arm_body"), "Move guard to arm body", target, |edit| {
-        match space_before_guard {
-            Some(element) if element.kind() == WHITESPACE => {
-                edit.delete(element.text_range());
-            }
-            _ => (),
-        };
+    acc.add(
+        AssistId("move_guard_to_arm_body", AssistKind::RefactorRewrite),
+        "Move guard to arm body",
+        target,
+        |edit| {
+            match space_before_guard {
+                Some(element) if element.kind() == WHITESPACE => {
+                    edit.delete(element.text_range());
+                }
+                _ => (),
+            };
 
-        edit.delete(guard.syntax().text_range());
-        edit.replace_node_and_indent(arm_expr.syntax(), buf);
-    })
+            edit.delete(guard.syntax().text_range());
+            edit.replace_node_and_indent(arm_expr.syntax(), buf);
+        },
+    )
 }
 
 // Assist: move_arm_cond_to_match_guard
@@ -100,7 +105,7 @@ pub(crate) fn move_arm_cond_to_match_guard(acc: &mut Assists, ctx: &AssistContex
 
     let target = if_expr.syntax().text_range();
     acc.add(
-        AssistId("move_arm_cond_to_match_guard"),
+        AssistId("move_arm_cond_to_match_guard", AssistKind::RefactorRewrite),
         "Move condition to match guard",
         target,
         |edit| {
diff --git a/crates/ra_assists/src/handlers/raw_string.rs b/crates/ra_assists/src/handlers/raw_string.rs
index 16002d2ac..6d77dff13 100644
--- a/crates/ra_assists/src/handlers/raw_string.rs
+++ b/crates/ra_assists/src/handlers/raw_string.rs
@@ -1,11 +1,13 @@
+use std::borrow::Cow;
+
 use ra_syntax::{
-    ast::{self, HasStringValue},
+    ast::{self, HasQuotes, HasStringValue},
     AstToken,
     SyntaxKind::{RAW_STRING, STRING},
     TextSize,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: make_raw_string
 //
@@ -26,14 +28,25 @@ pub(crate) fn make_raw_string(acc: &mut Assists, ctx: &AssistContext) -> Option<
     let token = ctx.find_token_at_offset(STRING).and_then(ast::String::cast)?;
     let value = token.value()?;
     let target = token.syntax().text_range();
-    acc.add(AssistId("make_raw_string"), "Rewrite as raw string", target, |edit| {
-        let max_hash_streak = count_hashes(&value);
-        let mut hashes = String::with_capacity(max_hash_streak + 1);
-        for _ in 0..hashes.capacity() {
-            hashes.push('#');
-        }
-        edit.replace(token.syntax().text_range(), format!("r{}\"{}\"{}", hashes, value, hashes));
-    })
+    acc.add(
+        AssistId("make_raw_string", AssistKind::RefactorRewrite),
+        "Rewrite as raw string",
+        target,
+        |edit| {
+            let max_hash_streak = count_hashes(&value);
+            let hashes = "#".repeat(max_hash_streak + 1);
+            if matches!(value, Cow::Borrowed(_)) {
+                // Avoid replacing the whole string to better position the cursor.
+                edit.insert(token.syntax().text_range().start(), format!("r{}", hashes));
+                edit.insert(token.syntax().text_range().end(), format!("{}", hashes));
+            } else {
+                edit.replace(
+                    token.syntax().text_range(),
+                    format!("r{}\"{}\"{}", hashes, value, hashes),
+                );
+            }
+        },
+    )
 }
 
 // Assist: make_usual_string
@@ -55,11 +68,24 @@ pub(crate) fn make_usual_string(acc: &mut Assists, ctx: &AssistContext) -> Optio
     let token = ctx.find_token_at_offset(RAW_STRING).and_then(ast::RawString::cast)?;
     let value = token.value()?;
     let target = token.syntax().text_range();
-    acc.add(AssistId("make_usual_string"), "Rewrite as regular string", target, |edit| {
-        // parse inside string to escape `"`
-        let escaped = value.escape_default().to_string();
-        edit.replace(token.syntax().text_range(), format!("\"{}\"", escaped));
-    })
+    acc.add(
+        AssistId("make_usual_string", AssistKind::RefactorRewrite),
+        "Rewrite as regular string",
+        target,
+        |edit| {
+            // parse inside string to escape `"`
+            let escaped = value.escape_default().to_string();
+            if let Some(offsets) = token.quote_offsets() {
+                if token.text()[offsets.contents - token.syntax().text_range().start()] == escaped {
+                    edit.replace(offsets.quotes.0, "\"");
+                    edit.replace(offsets.quotes.1, "\"");
+                    return;
+                }
+            }
+
+            edit.replace(token.syntax().text_range(), format!("\"{}\"", escaped));
+        },
+    )
 }
 
 // Assist: add_hash
@@ -80,7 +106,7 @@ pub(crate) fn make_usual_string(acc: &mut Assists, ctx: &AssistContext) -> Optio
 pub(crate) fn add_hash(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     let token = ctx.find_token_at_offset(RAW_STRING)?;
     let target = token.text_range();
-    acc.add(AssistId("add_hash"), "Add # to raw string", target, |edit| {
+    acc.add(AssistId("add_hash", AssistKind::Refactor), "Add # to raw string", target, |edit| {
         edit.insert(token.text_range().start() + TextSize::of('r'), "#");
         edit.insert(token.text_range().end(), "#");
     })
@@ -109,18 +135,23 @@ pub(crate) fn remove_hash(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
         return None;
     }
     let target = token.text_range();
-    acc.add(AssistId("remove_hash"), "Remove hash from raw string", target, |edit| {
-        let result = &text[2..text.len() - 1];
-        let result = if result.starts_with('\"') {
-            // FIXME: this logic is wrong, not only the last has has to handled specially
-            // no more hash, escape
-            let internal_str = &result[1..result.len() - 1];
-            format!("\"{}\"", internal_str.escape_default().to_string())
-        } else {
-            result.to_owned()
-        };
-        edit.replace(token.text_range(), format!("r{}", result));
-    })
+    acc.add(
+        AssistId("remove_hash", AssistKind::RefactorRewrite),
+        "Remove hash from raw string",
+        target,
+        |edit| {
+            let result = &text[2..text.len() - 1];
+            let result = if result.starts_with('\"') {
+                // FIXME: this logic is wrong, not only the last has has to handled specially
+                // no more hash, escape
+                let internal_str = &result[1..result.len() - 1];
+                format!("\"{}\"", internal_str.escape_default().to_string())
+            } else {
+                result.to_owned()
+            };
+            edit.replace(token.text_range(), format!("r{}", result));
+        },
+    )
 }
 
 fn count_hashes(s: &str) -> usize {
@@ -158,16 +189,16 @@ mod test {
         check_assist(
             make_raw_string,
             r#"
-            fn f() {
-                let s = <|>"random\nstring";
-            }
-            "#,
+fn f() {
+    let s = <|>"random\nstring";
+}
+"#,
             r##"
-            fn f() {
-                let s = r#"random
+fn f() {
+    let s = r#"random
 string"#;
-            }
-            "##,
+}
+"##,
         )
     }
 
@@ -193,16 +224,16 @@ string"#;
         check_assist(
             make_raw_string,
             r###"
-            fn f() {
-                let s = <|>"#random##\nstring";
-            }
-            "###,
+fn f() {
+    let s = <|>"#random##\nstring";
+}
+"###,
             r####"
-            fn f() {
-                let s = r#"#random##
+fn f() {
+    let s = r#"#random##
 string"#;
-            }
-            "####,
+}
+"####,
         )
     }
 
@@ -211,16 +242,16 @@ string"#;
         check_assist(
             make_raw_string,
             r###"
-            fn f() {
-                let s = <|>"#random\"##\nstring";
-            }
-            "###,
+fn f() {
+    let s = <|>"#random\"##\nstring";
+}
+"###,
             r####"
-            fn f() {
-                let s = r###"#random"##
+fn f() {
+    let s = r###"#random"##
 string"###;
-            }
-            "####,
+}
+"####,
         )
     }
 
diff --git a/crates/ra_assists/src/handlers/remove_dbg.rs b/crates/ra_assists/src/handlers/remove_dbg.rs
index 961ee1731..a616cca57 100644
--- a/crates/ra_assists/src/handlers/remove_dbg.rs
+++ b/crates/ra_assists/src/handlers/remove_dbg.rs
@@ -3,7 +3,7 @@ use ra_syntax::{
     TextSize, T,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: remove_dbg
 //
@@ -38,7 +38,7 @@ pub(crate) fn remove_dbg(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     };
 
     let target = macro_call.syntax().text_range();
-    acc.add(AssistId("remove_dbg"), "Remove dbg!()", target, |builder| {
+    acc.add(AssistId("remove_dbg", AssistKind::Refactor), "Remove dbg!()", target, |builder| {
         builder.replace(macro_range, macro_content);
     })
 }
diff --git a/crates/ra_assists/src/handlers/remove_mut.rs b/crates/ra_assists/src/handlers/remove_mut.rs
index fe4eada03..ef55c354e 100644
--- a/crates/ra_assists/src/handlers/remove_mut.rs
+++ b/crates/ra_assists/src/handlers/remove_mut.rs
@@ -1,6 +1,6 @@
 use ra_syntax::{SyntaxKind, TextRange, T};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: remove_mut
 //
@@ -26,7 +26,12 @@ pub(crate) fn remove_mut(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     };
 
     let target = mut_token.text_range();
-    acc.add(AssistId("remove_mut"), "Remove `mut` keyword", target, |builder| {
-        builder.delete(TextRange::new(delete_from, delete_to));
-    })
+    acc.add(
+        AssistId("remove_mut", AssistKind::Refactor),
+        "Remove `mut` keyword",
+        target,
+        |builder| {
+            builder.delete(TextRange::new(delete_from, delete_to));
+        },
+    )
 }
diff --git a/crates/ra_assists/src/handlers/reorder_fields.rs b/crates/ra_assists/src/handlers/reorder_fields.rs
index 897da2832..2ac1c56cf 100644
--- a/crates/ra_assists/src/handlers/reorder_fields.rs
+++ b/crates/ra_assists/src/handlers/reorder_fields.rs
@@ -1,11 +1,11 @@
-use std::collections::HashMap;
+use itertools::Itertools;
+use rustc_hash::FxHashMap;
 
 use hir::{Adt, ModuleDef, PathResolution, Semantics, Struct};
-use itertools::Itertools;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{algo, ast, match_ast, AstNode, SyntaxKind, SyntaxKind::*, SyntaxNode};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: reorder_fields
 //
@@ -42,11 +42,16 @@ fn reorder<R: AstNode>(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     }
 
     let target = record.syntax().text_range();
-    acc.add(AssistId("reorder_fields"), "Reorder record fields", target, |edit| {
-        for (old, new) in fields.iter().zip(&sorted_fields) {
-            algo::diff(old, new).into_text_edit(edit.text_edit_builder());
-        }
-    })
+    acc.add(
+        AssistId("reorder_fields", AssistKind::RefactorRewrite),
+        "Reorder record fields",
+        target,
+        |edit| {
+            for (old, new) in fields.iter().zip(&sorted_fields) {
+                algo::diff(old, new).into_text_edit(edit.text_edit_builder());
+            }
+        },
+    )
 }
 
 fn get_fields_kind(node: &SyntaxNode) -> Vec<SyntaxKind> {
@@ -87,13 +92,13 @@ fn struct_definition(path: &ast::Path, sema: &Semantics<RootDatabase>) -> Option
     }
 }
 
-fn compute_fields_ranks(path: &ast::Path, ctx: &AssistContext) -> Option<HashMap<String, usize>> {
+fn compute_fields_ranks(path: &ast::Path, ctx: &AssistContext) -> Option<FxHashMap<String, usize>> {
     Some(
         struct_definition(path, &ctx.sema)?
-            .fields(ctx.db)
+            .fields(ctx.db())
             .iter()
             .enumerate()
-            .map(|(idx, field)| (field.name(ctx.db).to_string(), idx))
+            .map(|(idx, field)| (field.name(ctx.db()).to_string(), idx))
             .collect(),
     )
 }
diff --git a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
index e016f51c3..b7e30a7f2 100644
--- a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
@@ -8,7 +8,7 @@ use ra_syntax::{
     AstNode,
 };
 
-use crate::{utils::TryEnum, AssistContext, AssistId, Assists};
+use crate::{utils::TryEnum, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: replace_if_let_with_match
 //
@@ -48,28 +48,35 @@ pub(crate) fn replace_if_let_with_match(acc: &mut Assists, ctx: &AssistContext)
     };
 
     let target = if_expr.syntax().text_range();
-    acc.add(AssistId("replace_if_let_with_match"), "Replace with match", target, move |edit| {
-        let match_expr = {
-            let then_arm = {
-                let then_expr = unwrap_trivial_block(then_block);
-                make::match_arm(vec![pat.clone()], then_expr)
+    acc.add(
+        AssistId("replace_if_let_with_match", AssistKind::RefactorRewrite),
+        "Replace with match",
+        target,
+        move |edit| {
+            let match_expr = {
+                let then_arm = {
+                    let then_block = then_block.reset_indent().indent(IndentLevel(1));
+                    let then_expr = unwrap_trivial_block(then_block);
+                    make::match_arm(vec![pat.clone()], then_expr)
+                };
+                let else_arm = {
+                    let pattern = ctx
+                        .sema
+                        .type_of_pat(&pat)
+                        .and_then(|ty| TryEnum::from_ty(&ctx.sema, &ty))
+                        .map(|it| it.sad_pattern())
+                        .unwrap_or_else(|| make::placeholder_pat().into());
+                    let else_expr = unwrap_trivial_block(else_block);
+                    make::match_arm(vec![pattern], else_expr)
+                };
+                let match_expr =
+                    make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]));
+                match_expr.indent(IndentLevel::from_node(if_expr.syntax()))
             };
-            let else_arm = {
-                let pattern = ctx
-                    .sema
-                    .type_of_pat(&pat)
-                    .and_then(|ty| TryEnum::from_ty(&ctx.sema, &ty))
-                    .map(|it| it.sad_pattern())
-                    .unwrap_or_else(|| make::placeholder_pat().into());
-                let else_expr = unwrap_trivial_block(else_block);
-                make::match_arm(vec![pattern], else_expr)
-            };
-            make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]))
-                .indent(IndentLevel::from_node(if_expr.syntax()))
-        };
 
-        edit.replace_ast::<ast::Expr>(if_expr.into(), match_expr);
-    })
+            edit.replace_ast::<ast::Expr>(if_expr.into(), match_expr);
+        },
+    )
 }
 
 #[cfg(test)]
@@ -213,4 +220,36 @@ fn foo(x: Result<i32, ()>) {
            "#,
         );
     }
+
+    #[test]
+    fn nested_indent() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+fn main() {
+    if true {
+        <|>if let Ok(rel_path) = path.strip_prefix(root_path) {
+            let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+            Some((*id, rel_path))
+        } else {
+            None
+        }
+    }
+}
+"#,
+            r#"
+fn main() {
+    if true {
+        match path.strip_prefix(root_path) {
+            Ok(rel_path) => {
+                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+                Some((*id, rel_path))
+            }
+            _ => None,
+        }
+    }
+}
+"#,
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/replace_let_with_if_let.rs b/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
index 761557ac0..a49292c97 100644
--- a/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
+++ b/crates/ra_assists/src/handlers/replace_let_with_if_let.rs
@@ -9,7 +9,7 @@ use ra_syntax::{
     AstNode, T,
 };
 
-use crate::{utils::TryEnum, AssistContext, AssistId, Assists};
+use crate::{utils::TryEnum, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: replace_let_with_if_let
 //
@@ -44,24 +44,31 @@ pub(crate) fn replace_let_with_if_let(acc: &mut Assists, ctx: &AssistContext) ->
     let happy_variant = TryEnum::from_ty(&ctx.sema, &ty).map(|it| it.happy_case());
 
     let target = let_kw.text_range();
-    acc.add(AssistId("replace_let_with_if_let"), "Replace with if-let", target, |edit| {
-        let with_placeholder: ast::Pat = match happy_variant {
-            None => make::placeholder_pat().into(),
-            Some(var_name) => make::tuple_struct_pat(
-                make::path_unqualified(make::path_segment(make::name_ref(var_name))),
-                once(make::placeholder_pat().into()),
-            )
-            .into(),
-        };
-        let block = make::block_expr(None, None).indent(IndentLevel::from_node(let_stmt.syntax()));
-        let if_ = make::expr_if(make::condition(init, Some(with_placeholder)), block);
-        let stmt = make::expr_stmt(if_);
+    acc.add(
+        AssistId("replace_let_with_if_let", AssistKind::RefactorRewrite),
+        "Replace with if-let",
+        target,
+        |edit| {
+            let with_placeholder: ast::Pat = match happy_variant {
+                None => make::placeholder_pat().into(),
+                Some(var_name) => make::tuple_struct_pat(
+                    make::path_unqualified(make::path_segment(make::name_ref(var_name))),
+                    once(make::placeholder_pat().into()),
+                )
+                .into(),
+            };
+            let block =
+                make::block_expr(None, None).indent(IndentLevel::from_node(let_stmt.syntax()));
+            let if_ = make::expr_if(make::condition(init, Some(with_placeholder)), block);
+            let stmt = make::expr_stmt(if_);
 
-        let placeholder = stmt.syntax().descendants().find_map(ast::PlaceholderPat::cast).unwrap();
-        let stmt = stmt.replace_descendant(placeholder.into(), original_pat);
+            let placeholder =
+                stmt.syntax().descendants().find_map(ast::PlaceholderPat::cast).unwrap();
+            let stmt = stmt.replace_descendant(placeholder.into(), original_pat);
 
-        edit.replace_ast(ast::Stmt::from(let_stmt), ast::Stmt::from(stmt));
-    })
+            edit.replace_ast(ast::Stmt::from(let_stmt), ast::Stmt::from(stmt));
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
index 0197a8cf0..dfd314abf 100644
--- a/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
+++ b/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs
@@ -1,7 +1,10 @@
 use hir;
-use ra_syntax::{ast, AstNode, SmolStr, TextRange};
+use ra_syntax::{algo::SyntaxRewriter, ast, match_ast, AstNode, SmolStr, SyntaxNode};
 
-use crate::{utils::insert_use_statement, AssistContext, AssistId, Assists};
+use crate::{
+    utils::{find_insert_use_container, insert_use_statement},
+    AssistContext, AssistId, AssistKind, Assists,
+};
 
 // Assist: replace_qualified_name_with_use
 //
@@ -34,21 +37,23 @@ pub(crate) fn replace_qualified_name_with_use(
 
     let target = path.syntax().text_range();
     acc.add(
-        AssistId("replace_qualified_name_with_use"),
+        AssistId("replace_qualified_name_with_use", AssistKind::RefactorRewrite),
         "Replace qualified path with use",
         target,
         |builder| {
             let path_to_import = hir_path.mod_path().clone();
+            let container = match find_insert_use_container(path.syntax(), ctx) {
+                Some(c) => c,
+                None => return,
+            };
             insert_use_statement(path.syntax(), &path_to_import, ctx, builder.text_edit_builder());
 
-            if let Some(last) = path.segment() {
-                // Here we are assuming the assist will provide a correct use statement
-                // so we can delete the path qualifier
-                builder.delete(TextRange::new(
-                    path.syntax().text_range().start(),
-                    last.syntax().text_range().start(),
-                ));
-            }
+            // Now that we've brought the name into scope, re-qualify all paths that could be
+            // affected (that is, all paths inside the node we added the `use` to).
+            let mut rewriter = SyntaxRewriter::default();
+            let syntax = container.either(|l| l.syntax().clone(), |r| r.syntax().clone());
+            shorten_paths(&mut rewriter, syntax, path);
+            builder.rewrite(rewriter);
         },
     )
 }
@@ -73,6 +78,69 @@ fn collect_hir_path_segments(path: &hir::Path) -> Option<Vec<SmolStr>> {
     Some(ps)
 }
 
+/// Adds replacements to `re` that shorten `path` in all descendants of `node`.
+fn shorten_paths(rewriter: &mut SyntaxRewriter<'static>, node: SyntaxNode, path: ast::Path) {
+    for child in node.children() {
+        match_ast! {
+            match child {
+                // Don't modify `use` items, as this can break the `use` item when injecting a new
+                // import into the use tree.
+                ast::UseItem(_it) => continue,
+                // Don't descend into submodules, they don't have the same `use` items in scope.
+                ast::Module(_it) => continue,
+
+                ast::Path(p) => {
+                    match maybe_replace_path(rewriter, p.clone(), path.clone()) {
+                        Some(()) => {},
+                        None => shorten_paths(rewriter, p.syntax().clone(), path.clone()),
+                    }
+                },
+                _ => shorten_paths(rewriter, child, path.clone()),
+            }
+        }
+    }
+}
+
+fn maybe_replace_path(
+    rewriter: &mut SyntaxRewriter<'static>,
+    path: ast::Path,
+    target: ast::Path,
+) -> Option<()> {
+    if !path_eq(path.clone(), target.clone()) {
+        return None;
+    }
+
+    // Shorten `path`, leaving only its last segment.
+    if let Some(parent) = path.qualifier() {
+        rewriter.delete(parent.syntax());
+    }
+    if let Some(double_colon) = path.coloncolon_token() {
+        rewriter.delete(&double_colon);
+    }
+
+    Some(())
+}
+
+fn path_eq(lhs: ast::Path, rhs: ast::Path) -> bool {
+    let mut lhs_curr = lhs;
+    let mut rhs_curr = rhs;
+    loop {
+        match (lhs_curr.segment(), rhs_curr.segment()) {
+            (Some(lhs), Some(rhs)) if lhs.syntax().text() == rhs.syntax().text() => (),
+            _ => return false,
+        }
+
+        match (lhs_curr.qualifier(), rhs_curr.qualifier()) {
+            (Some(lhs), Some(rhs)) => {
+                lhs_curr = lhs;
+                rhs_curr = rhs;
+            }
+            (None, None) => return true,
+            _ => return false,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::tests::{check_assist, check_assist_not_applicable};
@@ -83,10 +151,10 @@ mod tests {
     fn test_replace_add_use_no_anchor() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 std::fmt::Debug<|>
     ",
-            "
+            r"
 use std::fmt::Debug;
 
 Debug
@@ -97,13 +165,13 @@ Debug
     fn test_replace_add_use_no_anchor_with_item_below() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 std::fmt::Debug<|>
 
 fn main() {
 }
     ",
-            "
+            r"
 use std::fmt::Debug;
 
 Debug
@@ -118,13 +186,13 @@ fn main() {
     fn test_replace_add_use_no_anchor_with_item_above() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 fn main() {
 }
 
 std::fmt::Debug<|>
     ",
-            "
+            r"
 use std::fmt::Debug;
 
 fn main() {
@@ -139,10 +207,10 @@ Debug
     fn test_replace_add_use_no_anchor_2seg() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 std::fmt<|>::Debug
     ",
-            "
+            r"
 use std::fmt;
 
 fmt::Debug
@@ -154,13 +222,13 @@ fmt::Debug
     fn test_replace_add_use() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use stdx;
 
 impl std::fmt::Debug<|> for Foo {
 }
     ",
-            "
+            r"
 use stdx;
 use std::fmt::Debug;
 
@@ -174,11 +242,11 @@ impl Debug for Foo {
     fn test_replace_file_use_other_anchor() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 impl std::fmt::Debug<|> for Foo {
 }
     ",
-            "
+            r"
 use std::fmt::Debug;
 
 impl Debug for Foo {
@@ -191,11 +259,11 @@ impl Debug for Foo {
     fn test_replace_add_use_other_anchor_indent() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
     impl std::fmt::Debug<|> for Foo {
     }
     ",
-            "
+            r"
     use std::fmt::Debug;
 
     impl Debug for Foo {
@@ -208,13 +276,13 @@ impl Debug for Foo {
     fn test_replace_split_different() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt;
 
 impl std::io<|> for Foo {
 }
     ",
-            "
+            r"
 use std::{io, fmt};
 
 impl io for Foo {
@@ -227,13 +295,13 @@ impl io for Foo {
     fn test_replace_split_self_for_use() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt;
 
 impl std::fmt::Debug<|> for Foo {
 }
     ",
-            "
+            r"
 use std::fmt::{self, Debug, };
 
 impl Debug for Foo {
@@ -246,13 +314,13 @@ impl Debug for Foo {
     fn test_replace_split_self_for_target() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::Debug;
 
 impl std::fmt<|> for Foo {
 }
     ",
-            "
+            r"
 use std::fmt::{self, Debug};
 
 impl fmt for Foo {
@@ -265,13 +333,13 @@ impl fmt for Foo {
     fn test_replace_add_to_nested_self_nested() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::{Debug, nested::{Display}};
 
 impl std::fmt::nested<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt::{Debug, nested::{Display, self}};
 
 impl nested for Foo {
@@ -284,13 +352,13 @@ impl nested for Foo {
     fn test_replace_add_to_nested_self_already_included() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::{Debug, nested::{self, Display}};
 
 impl std::fmt::nested<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt::{Debug, nested::{self, Display}};
 
 impl nested for Foo {
@@ -303,13 +371,13 @@ impl nested for Foo {
     fn test_replace_add_to_nested_nested() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::{Debug, nested::{Display}};
 
 impl std::fmt::nested::Debug<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt::{Debug, nested::{Display, Debug}};
 
 impl Debug for Foo {
@@ -322,13 +390,13 @@ impl Debug for Foo {
     fn test_replace_split_common_target_longer() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::Debug;
 
 impl std::fmt::nested::Display<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt::{nested::Display, Debug};
 
 impl Display for Foo {
@@ -341,13 +409,13 @@ impl Display for Foo {
     fn test_replace_split_common_use_longer() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt::nested::Debug;
 
 impl std::fmt::Display<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt::{Display, nested::Debug};
 
 impl Display for Foo {
@@ -360,7 +428,7 @@ impl Display for Foo {
     fn test_replace_use_nested_import() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use crate::{
     ty::{Substs, Ty},
     AssocItem,
@@ -368,7 +436,7 @@ use crate::{
 
 fn foo() { crate::ty::lower<|>::trait_env() }
 ",
-            "
+            r"
 use crate::{
     ty::{Substs, Ty, lower},
     AssocItem,
@@ -383,13 +451,13 @@ fn foo() { lower::trait_env() }
     fn test_replace_alias() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt as foo;
 
 impl foo::Debug<|> for Foo {
 }
 ",
-            "
+            r"
 use std::fmt as foo;
 
 impl Debug for Foo {
@@ -402,7 +470,7 @@ impl Debug for Foo {
     fn test_replace_not_applicable_one_segment() {
         check_assist_not_applicable(
             replace_qualified_name_with_use,
-            "
+            r"
 impl foo<|> for Foo {
 }
 ",
@@ -413,7 +481,7 @@ impl foo<|> for Foo {
     fn test_replace_not_applicable_in_use() {
         check_assist_not_applicable(
             replace_qualified_name_with_use,
-            "
+            r"
 use std::fmt<|>;
 ",
         );
@@ -423,14 +491,14 @@ use std::fmt<|>;
     fn test_replace_add_use_no_anchor_in_mod_mod() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 mod foo {
     mod bar {
         std::fmt::Debug<|>
     }
 }
     ",
-            "
+            r"
 mod foo {
     mod bar {
         use std::fmt::Debug;
@@ -446,14 +514,14 @@ mod foo {
     fn inserts_imports_after_inner_attributes() {
         check_assist(
             replace_qualified_name_with_use,
-            "
+            r"
 #![allow(dead_code)]
 
 fn main() {
     std::fmt::Debug<|>
 }
     ",
-            "
+            r"
 #![allow(dead_code)]
 use std::fmt::Debug;
 
@@ -463,4 +531,116 @@ fn main() {
     ",
         );
     }
+
+    #[test]
+    fn replaces_all_affected_paths() {
+        check_assist(
+            replace_qualified_name_with_use,
+            r"
+fn main() {
+    std::fmt::Debug<|>;
+    let x: std::fmt::Debug = std::fmt::Debug;
+}
+    ",
+            r"
+use std::fmt::Debug;
+
+fn main() {
+    Debug;
+    let x: Debug = Debug;
+}
+    ",
+        );
+    }
+
+    #[test]
+    fn replaces_all_affected_paths_mod() {
+        check_assist(
+            replace_qualified_name_with_use,
+            r"
+mod m {
+    fn f() {
+        std::fmt::Debug<|>;
+        let x: std::fmt::Debug = std::fmt::Debug;
+    }
+    fn g() {
+        std::fmt::Debug;
+    }
+}
+
+fn f() {
+    std::fmt::Debug;
+}
+    ",
+            r"
+mod m {
+    use std::fmt::Debug;
+
+    fn f() {
+        Debug;
+        let x: Debug = Debug;
+    }
+    fn g() {
+        Debug;
+    }
+}
+
+fn f() {
+    std::fmt::Debug;
+}
+    ",
+        );
+    }
+
+    #[test]
+    fn does_not_replace_in_submodules() {
+        check_assist(
+            replace_qualified_name_with_use,
+            r"
+fn main() {
+    std::fmt::Debug<|>;
+}
+
+mod sub {
+    fn f() {
+        std::fmt::Debug;
+    }
+}
+    ",
+            r"
+use std::fmt::Debug;
+
+fn main() {
+    Debug;
+}
+
+mod sub {
+    fn f() {
+        std::fmt::Debug;
+    }
+}
+    ",
+        );
+    }
+
+    #[test]
+    fn does_not_replace_in_use() {
+        check_assist(
+            replace_qualified_name_with_use,
+            r"
+use std::fmt::Display;
+
+fn main() {
+    std::fmt<|>;
+}
+    ",
+            r"
+use std::fmt::{self, Display};
+
+fn main() {
+    fmt;
+}
+    ",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs b/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
index cff7dfb81..e5a4bb23c 100644
--- a/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
 
 use crate::{
     utils::{render_snippet, Cursor, TryEnum},
-    AssistContext, AssistId, Assists,
+    AssistContext, AssistId, AssistKind, Assists,
 };
 
 // Assist: replace_unwrap_with_match
@@ -46,37 +46,43 @@ pub(crate) fn replace_unwrap_with_match(acc: &mut Assists, ctx: &AssistContext)
     let ty = ctx.sema.type_of_expr(&caller)?;
     let happy_variant = TryEnum::from_ty(&ctx.sema, &ty)?.happy_case();
     let target = method_call.syntax().text_range();
-    acc.add(AssistId("replace_unwrap_with_match"), "Replace unwrap with match", target, |builder| {
-        let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
-        let it = make::bind_pat(make::name("a")).into();
-        let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
+    acc.add(
+        AssistId("replace_unwrap_with_match", AssistKind::RefactorRewrite),
+        "Replace unwrap with match",
+        target,
+        |builder| {
+            let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
+            let it = make::bind_pat(make::name("a")).into();
+            let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
 
-        let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
-        let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
+            let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
+            let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
 
-        let unreachable_call = make::expr_unreachable();
-        let err_arm = make::match_arm(iter::once(make::placeholder_pat().into()), unreachable_call);
+            let unreachable_call = make::expr_unreachable();
+            let err_arm =
+                make::match_arm(iter::once(make::placeholder_pat().into()), unreachable_call);
 
-        let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
-        let match_expr = make::expr_match(caller.clone(), match_arm_list)
-            .indent(IndentLevel::from_node(method_call.syntax()));
+            let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
+            let match_expr = make::expr_match(caller.clone(), match_arm_list)
+                .indent(IndentLevel::from_node(method_call.syntax()));
 
-        let range = method_call.syntax().text_range();
-        match ctx.config.snippet_cap {
-            Some(cap) => {
-                let err_arm = match_expr
-                    .syntax()
-                    .descendants()
-                    .filter_map(ast::MatchArm::cast)
-                    .last()
-                    .unwrap();
-                let snippet =
-                    render_snippet(cap, match_expr.syntax(), Cursor::Before(err_arm.syntax()));
-                builder.replace_snippet(cap, range, snippet)
+            let range = method_call.syntax().text_range();
+            match ctx.config.snippet_cap {
+                Some(cap) => {
+                    let err_arm = match_expr
+                        .syntax()
+                        .descendants()
+                        .filter_map(ast::MatchArm::cast)
+                        .last()
+                        .unwrap();
+                    let snippet =
+                        render_snippet(cap, match_expr.syntax(), Cursor::Before(err_arm.syntax()));
+                    builder.replace_snippet(cap, range, snippet)
+                }
+                None => builder.replace(range, match_expr.to_string()),
             }
-            None => builder.replace(range, match_expr.to_string()),
-        }
-    })
+        },
+    )
 }
 
 #[cfg(test)]
diff --git a/crates/ra_assists/src/handlers/split_import.rs b/crates/ra_assists/src/handlers/split_import.rs
index c7a874480..4ca5c3ca1 100644
--- a/crates/ra_assists/src/handlers/split_import.rs
+++ b/crates/ra_assists/src/handlers/split_import.rs
@@ -2,7 +2,7 @@ use std::iter::successors;
 
 use ra_syntax::{ast, AstNode, T};
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: split_import
 //
@@ -28,7 +28,7 @@ pub(crate) fn split_import(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     }
 
     let target = colon_colon.text_range();
-    acc.add(AssistId("split_import"), "Split import", target, |edit| {
+    acc.add(AssistId("split_import", AssistKind::RefactorRewrite), "Split import", target, |edit| {
         edit.replace_ast(use_tree, new_tree);
     })
 }
@@ -66,4 +66,14 @@ mod tests {
     fn issue4044() {
         check_assist_not_applicable(split_import, "use crate::<|>:::self;")
     }
+
+    #[test]
+    fn test_empty_use() {
+        check_assist_not_applicable(
+            split_import,
+            r"
+use std::<|>
+fn main() {}",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/unwrap_block.rs b/crates/ra_assists/src/handlers/unwrap_block.rs
index 8440c7d0f..8b38695a9 100644
--- a/crates/ra_assists/src/handlers/unwrap_block.rs
+++ b/crates/ra_assists/src/handlers/unwrap_block.rs
@@ -1,10 +1,13 @@
 use ra_fmt::unwrap_trivial_block;
 use ra_syntax::{
-    ast::{self, ElseBranch, Expr, LoopBodyOwner},
-    match_ast, AstNode, TextRange, T,
+    ast::{
+        self,
+        edit::{AstNodeEdit, IndentLevel},
+    },
+    AstNode, TextRange, T,
 };
 
-use crate::{AssistContext, AssistId, Assists};
+use crate::{AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: unwrap_block
 //
@@ -24,94 +27,73 @@ use crate::{AssistContext, AssistId, Assists};
 // }
 // ```
 pub(crate) fn unwrap_block(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let l_curly_token = ctx.find_token_at_offset(T!['{'])?;
-    let block = ast::BlockExpr::cast(l_curly_token.parent())?;
-    let parent = block.syntax().parent()?;
-    let assist_id = AssistId("unwrap_block");
+    let assist_id = AssistId("unwrap_block", AssistKind::RefactorRewrite);
     let assist_label = "Unwrap block";
 
-    let (expr, expr_to_unwrap) = match_ast! {
-        match parent {
-            ast::ForExpr(for_expr) => {
-                let block_expr = for_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::ForExpr(for_expr), expr_to_unwrap)
-            },
-            ast::WhileExpr(while_expr) => {
-                let block_expr = while_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::WhileExpr(while_expr), expr_to_unwrap)
-            },
-            ast::LoopExpr(loop_expr) => {
-                let block_expr = loop_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::LoopExpr(loop_expr), expr_to_unwrap)
-            },
-            ast::IfExpr(if_expr) => {
-                let mut resp = None;
-
-                let then_branch = if_expr.then_branch()?;
-                if then_branch.l_curly_token()?.text_range().contains_range(ctx.frange.range) {
-                    if let Some(ancestor) = if_expr.syntax().parent().and_then(ast::IfExpr::cast) {
-                        // For `else if` blocks
-                        let ancestor_then_branch = ancestor.then_branch()?;
-                        let l_curly_token = then_branch.l_curly_token()?;
-
-                        let target = then_branch.syntax().text_range();
-                        return acc.add(assist_id, assist_label, target, |edit| {
-                            let range_to_del_else_if = TextRange::new(ancestor_then_branch.syntax().text_range().end(), l_curly_token.text_range().start());
-                            let range_to_del_rest = TextRange::new(then_branch.syntax().text_range().end(), if_expr.syntax().text_range().end());
-
-                            edit.delete(range_to_del_rest);
-                            edit.delete(range_to_del_else_if);
-                            edit.replace(target, update_expr_string(then_branch.to_string(), &[' ', '{']));
-                        });
-                    } else {
-                        resp = Some((ast::Expr::IfExpr(if_expr.clone()), Expr::BlockExpr(then_branch)));
-                    }
-                } else if let Some(else_branch) = if_expr.else_branch() {
-                    match else_branch {
-                        ElseBranch::Block(else_block) => {
-                            let l_curly_token = else_block.l_curly_token()?;
-                            if l_curly_token.text_range().contains_range(ctx.frange.range) {
-                                let target = else_block.syntax().text_range();
-                                return acc.add(assist_id, assist_label, target, |edit| {
-                                    let range_to_del = TextRange::new(then_branch.syntax().text_range().end(), l_curly_token.text_range().start());
-
-                                    edit.delete(range_to_del);
-                                    edit.replace(target, update_expr_string(else_block.to_string(), &[' ', '{']));
-                                });
-                            }
-                        },
-                        ElseBranch::IfExpr(_) => {},
-                    }
-                }
+    let l_curly_token = ctx.find_token_at_offset(T!['{'])?;
+    let mut block = ast::BlockExpr::cast(l_curly_token.parent())?;
+    let mut parent = block.syntax().parent()?;
+    if ast::MatchArm::can_cast(parent.kind()) {
+        parent = parent.ancestors().find(|it| ast::MatchExpr::can_cast(it.kind()))?
+    }
 
-                resp?
-            },
-            _ => return None,
+    let parent = ast::Expr::cast(parent)?;
+
+    match parent.clone() {
+        ast::Expr::ForExpr(_) | ast::Expr::WhileExpr(_) | ast::Expr::LoopExpr(_) => (),
+        ast::Expr::MatchExpr(_) => block = block.dedent(IndentLevel(1)),
+        ast::Expr::IfExpr(if_expr) => {
+            let then_branch = if_expr.then_branch()?;
+            if then_branch == block {
+                if let Some(ancestor) = if_expr.syntax().parent().and_then(ast::IfExpr::cast) {
+                    // For `else if` blocks
+                    let ancestor_then_branch = ancestor.then_branch()?;
+
+                    let target = then_branch.syntax().text_range();
+                    return acc.add(assist_id, assist_label, target, |edit| {
+                        let range_to_del_else_if = TextRange::new(
+                            ancestor_then_branch.syntax().text_range().end(),
+                            l_curly_token.text_range().start(),
+                        );
+                        let range_to_del_rest = TextRange::new(
+                            then_branch.syntax().text_range().end(),
+                            if_expr.syntax().text_range().end(),
+                        );
+
+                        edit.delete(range_to_del_rest);
+                        edit.delete(range_to_del_else_if);
+                        edit.replace(
+                            target,
+                            update_expr_string(then_branch.to_string(), &[' ', '{']),
+                        );
+                    });
+                }
+            } else {
+                let target = block.syntax().text_range();
+                return acc.add(assist_id, assist_label, target, |edit| {
+                    let range_to_del = TextRange::new(
+                        then_branch.syntax().text_range().end(),
+                        l_curly_token.text_range().start(),
+                    );
+
+                    edit.delete(range_to_del);
+                    edit.replace(target, update_expr_string(block.to_string(), &[' ', '{']));
+                });
+            }
         }
+        _ => return None,
     };
 
-    let target = expr_to_unwrap.syntax().text_range();
-    acc.add(assist_id, assist_label, target, |edit| {
-        edit.replace(
-            expr.syntax().text_range(),
-            update_expr_string(expr_to_unwrap.to_string(), &[' ', '{', '\n']),
+    let unwrapped = unwrap_trivial_block(block);
+    let target = unwrapped.syntax().text_range();
+    acc.add(assist_id, assist_label, target, |builder| {
+        builder.replace(
+            parent.syntax().text_range(),
+            update_expr_string(unwrapped.to_string(), &[' ', '{', '\n']),
         );
     })
 }
 
-fn extract_expr(cursor_range: TextRange, block: ast::BlockExpr) -> Option<ast::Expr> {
-    let cursor_in_range = block.l_curly_token()?.text_range().contains_range(cursor_range);
-
-    if cursor_in_range {
-        Some(unwrap_trivial_block(block))
-    } else {
-        None
-    }
-}
-
 fn update_expr_string(expr_str: String, trim_start_pat: &[char]) -> String {
     let expr_string = expr_str.trim_start_matches(trim_start_pat);
     let mut expr_string_lines: Vec<&str> = expr_string.lines().collect();
@@ -490,6 +472,30 @@ mod tests {
     }
 
     #[test]
+    fn unwrap_match_arm() {
+        check_assist(
+            unwrap_block,
+            r#"
+fn main() {
+    match rel_path {
+        Ok(rel_path) => {<|>
+            let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+            Some((*id, rel_path))
+        }
+        Err(_) => None,
+    }
+}
+"#,
+            r#"
+fn main() {
+    let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+    Some((*id, rel_path))
+}
+"#,
+        );
+    }
+
+    #[test]
     fn simple_if_in_while_bad_cursor_position() {
         check_assist_not_applicable(
             unwrap_block,
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 3f8f7ffbf..465b90415 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -26,10 +26,40 @@ pub(crate) use crate::assist_context::{AssistContext, Assists};
 
 pub use assist_config::AssistConfig;
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AssistKind {
+    None,
+    QuickFix,
+    Generate,
+    Refactor,
+    RefactorExtract,
+    RefactorInline,
+    RefactorRewrite,
+}
+
+impl AssistKind {
+    pub fn contains(self, other: AssistKind) -> bool {
+        if self == other {
+            return true;
+        }
+
+        match self {
+            AssistKind::None | AssistKind::Generate => return true,
+            AssistKind::Refactor => match other {
+                AssistKind::RefactorExtract
+                | AssistKind::RefactorInline
+                | AssistKind::RefactorRewrite => return true,
+                _ => return false,
+            },
+            _ => return false,
+        }
+    }
+}
+
 /// Unique identifier of the assist, should not be shown to the user
 /// directly.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct AssistId(pub &'static str);
+pub struct AssistId(pub &'static str, pub AssistKind);
 
 #[derive(Clone, Debug)]
 pub struct GroupLabel(pub String);
@@ -102,27 +132,28 @@ mod handlers {
     pub(crate) type Handler = fn(&mut Assists, &AssistContext) -> Option<()>;
 
     mod add_custom_impl;
-    mod add_derive;
     mod add_explicit_type;
-    mod add_from_impl_for_enum;
-    mod add_function;
-    mod add_impl;
     mod add_missing_impl_members;
-    mod add_new;
     mod add_turbo_fish;
     mod apply_demorgan;
     mod auto_import;
-    mod change_lifetime_anon_to_named;
     mod change_return_type_to_result;
     mod change_visibility;
     mod early_return;
+    mod extract_struct_from_enum_variant;
+    mod extract_variable;
     mod fill_match_arms;
     mod fix_visibility;
     mod flip_binexpr;
     mod flip_comma;
     mod flip_trait_bound;
+    mod generate_derive;
+    mod generate_from_impl_for_enum;
+    mod generate_function;
+    mod generate_impl;
+    mod generate_new;
     mod inline_local_variable;
-    mod introduce_variable;
+    mod introduce_named_lifetime;
     mod invert_if;
     mod merge_imports;
     mod merge_match_arms;
@@ -143,26 +174,27 @@ mod handlers {
         &[
             // These are alphabetic for the foolish consistency
             add_custom_impl::add_custom_impl,
-            add_derive::add_derive,
             add_explicit_type::add_explicit_type,
-            add_from_impl_for_enum::add_from_impl_for_enum,
-            add_function::add_function,
-            add_impl::add_impl,
-            add_new::add_new,
             add_turbo_fish::add_turbo_fish,
             apply_demorgan::apply_demorgan,
             auto_import::auto_import,
-            change_lifetime_anon_to_named::change_lifetime_anon_to_named,
             change_return_type_to_result::change_return_type_to_result,
             change_visibility::change_visibility,
             early_return::convert_to_guarded_return,
+            extract_struct_from_enum_variant::extract_struct_from_enum_variant,
+            extract_variable::extract_variable,
             fill_match_arms::fill_match_arms,
             fix_visibility::fix_visibility,
             flip_binexpr::flip_binexpr,
             flip_comma::flip_comma,
             flip_trait_bound::flip_trait_bound,
+            generate_derive::generate_derive,
+            generate_from_impl_for_enum::generate_from_impl_for_enum,
+            generate_function::generate_function,
+            generate_impl::generate_impl,
+            generate_new::generate_new,
             inline_local_variable::inline_local_variable,
-            introduce_variable::introduce_variable,
+            introduce_named_lifetime::introduce_named_lifetime,
             invert_if::invert_if,
             merge_imports::merge_imports,
             merge_match_arms::merge_match_arms,
diff --git a/crates/ra_assists/src/tests.rs b/crates/ra_assists/src/tests.rs
index 62dd3547f..18fcb9049 100644
--- a/crates/ra_assists/src/tests.rs
+++ b/crates/ra_assists/src/tests.rs
@@ -1,27 +1,21 @@
 mod generated;
 
-use std::sync::Arc;
-
 use hir::Semantics;
 use ra_db::{fixture::WithFixture, FileId, FileRange, SourceDatabaseExt};
-use ra_ide_db::{symbol_index::SymbolsDatabase, RootDatabase};
+use ra_ide_db::RootDatabase;
 use ra_syntax::TextRange;
-use test_utils::{
-    assert_eq_text, extract_offset, extract_range, extract_range_or_offset, RangeOrOffset,
-};
+use test_utils::{assert_eq_text, extract_offset, extract_range};
 
-use crate::{handlers::Handler, Assist, AssistConfig, AssistContext, Assists};
+use crate::{handlers::Handler, Assist, AssistConfig, AssistContext, AssistKind, Assists};
+use stdx::trim_indent;
 
 pub(crate) fn with_single_file(text: &str) -> (RootDatabase, FileId) {
-    let (mut db, file_id) = RootDatabase::with_single_file(text);
-    // FIXME: ideally, this should be done by the above `RootDatabase::with_single_file`,
-    // but it looks like this might need specialization? :(
-    db.set_local_roots(Arc::new(vec![db.file_source_root(file_id)]));
-    (db, file_id)
+    RootDatabase::with_single_file(text)
 }
 
 pub(crate) fn check_assist(assist: Handler, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(assist, ra_fixture_before, ExpectedResult::After(ra_fixture_after));
+    let ra_fixture_after = trim_indent(ra_fixture_after);
+    check(assist, ra_fixture_before, ExpectedResult::After(&ra_fixture_after));
 }
 
 // FIXME: instead of having a separate function here, maybe use
@@ -36,8 +30,9 @@ pub(crate) fn check_assist_not_applicable(assist: Handler, ra_fixture: &str) {
 }
 
 fn check_doc_test(assist_id: &str, before: &str, after: &str) {
-    let (selection, before) = extract_range_or_offset(before);
-    let (db, file_id) = crate::tests::with_single_file(&before);
+    let after = trim_indent(after);
+    let (db, file_id, selection) = RootDatabase::with_range_or_offset(&before);
+    let before = db.file_text(file_id).to_string();
     let frange = FileRange { file_id, range: selection.into() };
 
     let mut assist = Assist::resolved(&db, &AssistConfig::default(), frange)
@@ -57,11 +52,11 @@ fn check_doc_test(assist_id: &str, before: &str, after: &str) {
 
     let actual = {
         let change = assist.source_change.source_file_edits.pop().unwrap();
-        let mut actual = before.clone();
+        let mut actual = before;
         change.edit.apply(&mut actual);
         actual
     };
-    assert_eq_text!(after, &actual);
+    assert_eq_text!(&after, &actual);
 }
 
 enum ExpectedResult<'a> {
@@ -71,20 +66,8 @@ enum ExpectedResult<'a> {
 }
 
 fn check(handler: Handler, before: &str, expected: ExpectedResult) {
-    let (text_without_caret, file_with_caret_id, range_or_offset, db) = if before.contains("//-") {
-        let (mut db, position) = RootDatabase::with_position(before);
-        db.set_local_roots(Arc::new(vec![db.file_source_root(position.file_id)]));
-        (
-            db.file_text(position.file_id).as_ref().to_owned(),
-            position.file_id,
-            RangeOrOffset::Offset(position.offset),
-            db,
-        )
-    } else {
-        let (range_or_offset, text_without_caret) = extract_range_or_offset(before);
-        let (db, file_id) = with_single_file(&text_without_caret);
-        (text_without_caret, file_id, range_or_offset, db)
-    };
+    let (db, file_with_caret_id, range_or_offset) = RootDatabase::with_range_or_offset(before);
+    let text_without_caret = db.file_text(file_with_caret_id).to_string();
 
     let frange = FileRange { file_id: file_with_caret_id, range: range_or_offset.into() };
 
@@ -151,3 +134,46 @@ fn assist_order_if_expr() {
     assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
     assert_eq!(assists.next().expect("expected assist").assist.label, "Replace with match");
 }
+
+#[test]
+fn assist_filter_works() {
+    let before = "
+    pub fn test_some_range(a: int) -> bool {
+        if let 2..6 = <|>5<|> {
+            true
+        } else {
+            false
+        }
+    }";
+    let (range, before) = extract_range(before);
+    let (db, file_id) = with_single_file(&before);
+    let frange = FileRange { file_id, range };
+
+    {
+        let mut cfg = AssistConfig::default();
+        cfg.allowed = Some(vec![AssistKind::Refactor]);
+
+        let assists = Assist::resolved(&db, &cfg, frange);
+        let mut assists = assists.iter();
+
+        assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
+        assert_eq!(assists.next().expect("expected assist").assist.label, "Replace with match");
+    }
+
+    {
+        let mut cfg = AssistConfig::default();
+        cfg.allowed = Some(vec![AssistKind::RefactorExtract]);
+        let assists = Assist::resolved(&db, &cfg, frange);
+        assert_eq!(assists.len(), 1);
+
+        let mut assists = assists.iter();
+        assert_eq!(assists.next().expect("expected assist").assist.label, "Extract into variable");
+    }
+
+    {
+        let mut cfg = AssistConfig::default();
+        cfg.allowed = Some(vec![AssistKind::QuickFix]);
+        let assists = Assist::resolved(&db, &cfg, frange);
+        assert!(assists.is_empty(), "All asserts but quickfixes should be filtered out");
+    }
+}
diff --git a/crates/ra_assists/src/tests/generated.rs b/crates/ra_assists/src/tests/generated.rs
index 73d43283d..eff7feded 100644
--- a/crates/ra_assists/src/tests/generated.rs
+++ b/crates/ra_assists/src/tests/generated.rs
@@ -22,26 +22,6 @@ impl Debug for S {
 }
 
 #[test]
-fn doctest_add_derive() {
-    check_doc_test(
-        "add_derive",
-        r#####"
-struct Point {
-    x: u32,
-    y: u32,<|>
-}
-"#####,
-        r#####"
-#[derive($0)]
-struct Point {
-    x: u32,
-    y: u32,
-}
-"#####,
-    )
-}
-
-#[test]
 fn doctest_add_explicit_type() {
     check_doc_test(
         "add_explicit_type",
@@ -59,52 +39,6 @@ fn main() {
 }
 
 #[test]
-fn doctest_add_from_impl_for_enum() {
-    check_doc_test(
-        "add_from_impl_for_enum",
-        r#####"
-enum A { <|>One(u32) }
-"#####,
-        r#####"
-enum A { One(u32) }
-
-impl From<u32> for A {
-    fn from(v: u32) -> Self {
-        A::One(v)
-    }
-}
-"#####,
-    )
-}
-
-#[test]
-fn doctest_add_function() {
-    check_doc_test(
-        "add_function",
-        r#####"
-struct Baz;
-fn baz() -> Baz { Baz }
-fn foo() {
-    bar<|>("", baz());
-}
-
-"#####,
-        r#####"
-struct Baz;
-fn baz() -> Baz { Baz }
-fn foo() {
-    bar("", baz());
-}
-
-fn bar(arg: &str, baz: Baz) {
-    ${0:todo!()}
-}
-
-"#####,
-    )
-}
-
-#[test]
 fn doctest_add_hash() {
     check_doc_test(
         "add_hash",
@@ -122,27 +56,6 @@ fn main() {
 }
 
 #[test]
-fn doctest_add_impl() {
-    check_doc_test(
-        "add_impl",
-        r#####"
-struct Ctx<T: Clone> {
-    data: T,<|>
-}
-"#####,
-        r#####"
-struct Ctx<T: Clone> {
-    data: T,
-}
-
-impl<T: Clone> Ctx<T> {
-    $0
-}
-"#####,
-    )
-}
-
-#[test]
 fn doctest_add_impl_default_members() {
     check_doc_test(
         "add_impl_default_members",
@@ -209,28 +122,6 @@ impl Trait<u32> for () {
 }
 
 #[test]
-fn doctest_add_new() {
-    check_doc_test(
-        "add_new",
-        r#####"
-struct Ctx<T: Clone> {
-     data: T,<|>
-}
-"#####,
-        r#####"
-struct Ctx<T: Clone> {
-     data: T,
-}
-
-impl<T: Clone> Ctx<T> {
-    fn $0new(data: T) -> Self { Self { data } }
-}
-
-"#####,
-    )
-}
-
-#[test]
 fn doctest_add_turbo_fish() {
     check_doc_test(
         "add_turbo_fish",
@@ -288,31 +179,6 @@ pub mod std { pub mod collections { pub struct HashMap { } } }
 }
 
 #[test]
-fn doctest_change_lifetime_anon_to_named() {
-    check_doc_test(
-        "change_lifetime_anon_to_named",
-        r#####"
-impl Cursor<'_<|>> {
-    fn node(self) -> &SyntaxNode {
-        match self {
-            Cursor::Replace(node) | Cursor::Before(node) => node,
-        }
-    }
-}
-"#####,
-        r#####"
-impl<'a> Cursor<'a> {
-    fn node(self) -> &SyntaxNode {
-        match self {
-            Cursor::Replace(node) | Cursor::Before(node) => node,
-        }
-    }
-}
-"#####,
-    )
-}
-
-#[test]
 fn doctest_change_return_type_to_result() {
     check_doc_test(
         "change_return_type_to_result",
@@ -363,6 +229,39 @@ fn main() {
 }
 
 #[test]
+fn doctest_extract_struct_from_enum_variant() {
+    check_doc_test(
+        "extract_struct_from_enum_variant",
+        r#####"
+enum A { <|>One(u32, u32) }
+"#####,
+        r#####"
+struct One(pub u32, pub u32);
+
+enum A { One(One) }
+"#####,
+    )
+}
+
+#[test]
+fn doctest_extract_variable() {
+    check_doc_test(
+        "extract_variable",
+        r#####"
+fn main() {
+    <|>(1 + 2)<|> * 4;
+}
+"#####,
+        r#####"
+fn main() {
+    let $0var_name = (1 + 2);
+    var_name * 4;
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_fill_match_arms() {
     check_doc_test(
         "fill_match_arms",
@@ -459,6 +358,115 @@ fn foo<T: Copy + Clone>() { }
 }
 
 #[test]
+fn doctest_generate_derive() {
+    check_doc_test(
+        "generate_derive",
+        r#####"
+struct Point {
+    x: u32,
+    y: u32,<|>
+}
+"#####,
+        r#####"
+#[derive($0)]
+struct Point {
+    x: u32,
+    y: u32,
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_generate_from_impl_for_enum() {
+    check_doc_test(
+        "generate_from_impl_for_enum",
+        r#####"
+enum A { <|>One(u32) }
+"#####,
+        r#####"
+enum A { One(u32) }
+
+impl From<u32> for A {
+    fn from(v: u32) -> Self {
+        A::One(v)
+    }
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_generate_function() {
+    check_doc_test(
+        "generate_function",
+        r#####"
+struct Baz;
+fn baz() -> Baz { Baz }
+fn foo() {
+    bar<|>("", baz());
+}
+
+"#####,
+        r#####"
+struct Baz;
+fn baz() -> Baz { Baz }
+fn foo() {
+    bar("", baz());
+}
+
+fn bar(arg: &str, baz: Baz) {
+    ${0:todo!()}
+}
+
+"#####,
+    )
+}
+
+#[test]
+fn doctest_generate_impl() {
+    check_doc_test(
+        "generate_impl",
+        r#####"
+struct Ctx<T: Clone> {
+    data: T,<|>
+}
+"#####,
+        r#####"
+struct Ctx<T: Clone> {
+    data: T,
+}
+
+impl<T: Clone> Ctx<T> {
+    $0
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_generate_new() {
+    check_doc_test(
+        "generate_new",
+        r#####"
+struct Ctx<T: Clone> {
+     data: T,<|>
+}
+"#####,
+        r#####"
+struct Ctx<T: Clone> {
+     data: T,
+}
+
+impl<T: Clone> Ctx<T> {
+    fn $0new(data: T) -> Self { Self { data } }
+}
+
+"#####,
+    )
+}
+
+#[test]
 fn doctest_inline_local_variable() {
     check_doc_test(
         "inline_local_variable",
@@ -477,18 +485,25 @@ fn main() {
 }
 
 #[test]
-fn doctest_introduce_variable() {
+fn doctest_introduce_named_lifetime() {
     check_doc_test(
-        "introduce_variable",
+        "introduce_named_lifetime",
         r#####"
-fn main() {
-    <|>(1 + 2)<|> * 4;
+impl Cursor<'_<|>> {
+    fn node(self) -> &SyntaxNode {
+        match self {
+            Cursor::Replace(node) | Cursor::Before(node) => node,
+        }
+    }
 }
 "#####,
         r#####"
-fn main() {
-    let $0var_name = (1 + 2);
-    var_name * 4;
+impl<'a> Cursor<'a> {
+    fn node(self) -> &SyntaxNode {
+        match self {
+            Cursor::Replace(node) | Cursor::Before(node) => node,
+        }
+    }
 }
 "#####,
     )
diff --git a/crates/ra_assists/src/utils.rs b/crates/ra_assists/src/utils.rs
index 0038a9764..02de902d6 100644
--- a/crates/ra_assists/src/utils.rs
+++ b/crates/ra_assists/src/utils.rs
@@ -7,13 +7,15 @@ use hir::{Adt, Crate, Enum, ScopeDef, Semantics, Trait, Type};
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
     ast::{self, make, NameOwner},
-    AstNode, SyntaxNode, T,
+    AstNode,
+    SyntaxKind::*,
+    SyntaxNode, TextSize, T,
 };
 use rustc_hash::FxHashSet;
 
 use crate::assist_config::SnippetCap;
 
-pub(crate) use insert_use::insert_use_statement;
+pub(crate) use insert_use::{find_insert_use_container, insert_use_statement};
 
 #[derive(Clone, Copy, Debug)]
 pub(crate) enum Cursor<'a> {
@@ -120,6 +122,13 @@ pub(crate) fn resolve_target_trait(
     }
 }
 
+pub(crate) fn vis_offset(node: &SyntaxNode) -> TextSize {
+    node.children_with_tokens()
+        .find(|it| !matches!(it.kind(), WHITESPACE | COMMENT | ATTR))
+        .map(|it| it.text_range().start())
+        .unwrap_or_else(|| node.text_range().start())
+}
+
 pub(crate) fn invert_boolean_expression(expr: ast::Expr) -> ast::Expr {
     if let Some(expr) = invert_special_case(&expr) {
         return expr;
@@ -198,8 +207,7 @@ pub(crate) struct FamousDefs<'a, 'b>(pub(crate) &'a Semantics<'b, RootDatabase>,
 #[allow(non_snake_case)]
 impl FamousDefs<'_, '_> {
     #[cfg(test)]
-    pub(crate) const FIXTURE: &'static str = r#"
-//- /libcore.rs crate:core
+    pub(crate) const FIXTURE: &'static str = r#"//- /libcore.rs crate:core
 pub mod convert {
     pub trait From<T> {
         fn from(T) -> Self;
diff --git a/crates/ra_assists/src/utils/insert_use.rs b/crates/ra_assists/src/utils/insert_use.rs
index 0ee43482f..8c4f33e59 100644
--- a/crates/ra_assists/src/utils/insert_use.rs
+++ b/crates/ra_assists/src/utils/insert_use.rs
@@ -12,6 +12,20 @@ use ra_syntax::{
 use ra_text_edit::TextEditBuilder;
 
 use crate::assist_context::AssistContext;
+use either::Either;
+
+/// Determines the containing syntax node in which to insert a `use` statement affecting `position`.
+pub(crate) fn find_insert_use_container(
+    position: &SyntaxNode,
+    ctx: &AssistContext,
+) -> Option<Either<ast::ItemList, ast::SourceFile>> {
+    ctx.sema.ancestors_with_macros(position.clone()).find_map(|n| {
+        if let Some(module) = ast::Module::cast(n.clone()) {
+            return module.item_list().map(|it| Either::Left(it));
+        }
+        Some(Either::Right(ast::SourceFile::cast(n)?))
+    })
+}
 
 /// Creates and inserts a use statement for the given path to import.
 /// The use statement is inserted in the scope most appropriate to the
@@ -24,15 +38,11 @@ pub(crate) fn insert_use_statement(
     builder: &mut TextEditBuilder,
 ) {
     let target = path_to_import.to_string().split("::").map(SmolStr::new).collect::<Vec<_>>();
-    let container = ctx.sema.ancestors_with_macros(position.clone()).find_map(|n| {
-        if let Some(module) = ast::Module::cast(n.clone()) {
-            return module.item_list().map(|it| it.syntax().clone());
-        }
-        ast::SourceFile::cast(n).map(|it| it.syntax().clone())
-    });
+    let container = find_insert_use_container(position, ctx);
 
     if let Some(container) = container {
-        let action = best_action_for_target(container, position.clone(), &target);
+        let syntax = container.either(|l| l.syntax().clone(), |r| r.syntax().clone());
+        let action = best_action_for_target(syntax, position.clone(), &target);
         make_assist(&action, &target, builder);
     }
 }
diff --git a/crates/ra_cfg/Cargo.toml b/crates/ra_cfg/Cargo.toml
index 9165076a5..6425cd6d6 100644
--- a/crates/ra_cfg/Cargo.toml
+++ b/crates/ra_cfg/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_cfg"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs
index 57feabcb2..f9c73ece1 100644
--- a/crates/ra_cfg/src/lib.rs
+++ b/crates/ra_cfg/src/lib.rs
@@ -46,4 +46,14 @@ impl CfgOptions {
     pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) {
         self.key_values.insert((key, value));
     }
+
+    pub fn append(&mut self, other: &CfgOptions) {
+        for atom in &other.atoms {
+            self.atoms.insert(atom.clone());
+        }
+
+        for (key, value) in &other.key_values {
+            self.key_values.insert((key.clone(), value.clone()));
+        }
+    }
 }
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 8ab409158..5f334d04f 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -3,13 +3,13 @@ edition = "2018"
 name = "ra_db"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
 
 [dependencies]
-salsa = "0.14.1"
-relative-path = "1.0.0"
+salsa = "0.15.0"
 rustc-hash = "1.1.0"
 
 ra_syntax = { path = "../ra_syntax" }
@@ -17,3 +17,5 @@ ra_cfg = { path = "../ra_cfg" }
 ra_prof = { path = "../ra_prof" }
 ra_tt = { path = "../ra_tt" }
 test_utils = { path = "../test_utils" }
+vfs = { path = "../vfs" }
+stdx = { path = "../stdx" }
diff --git a/crates/ra_db/src/fixture.rs b/crates/ra_db/src/fixture.rs
index 482a2f3e6..209713987 100644
--- a/crates/ra_db/src/fixture.rs
+++ b/crates/ra_db/src/fixture.rs
@@ -57,17 +57,16 @@
 //! fn insert_source_code_here() {}
 //! "
 //! ```
-
-use std::str::FromStr;
-use std::sync::Arc;
+use std::{str::FromStr, sync::Arc};
 
 use ra_cfg::CfgOptions;
 use rustc_hash::FxHashMap;
-use test_utils::{extract_offset, parse_fixture, parse_single_fixture, FixtureMeta, CURSOR_MARKER};
+use test_utils::{extract_range_or_offset, Fixture, RangeOrOffset, CURSOR_MARKER};
+use vfs::{file_set::FileSet, VfsPath};
 
 use crate::{
-    input::CrateName, CrateGraph, CrateId, Edition, Env, FileId, FilePosition, RelativePathBuf,
-    SourceDatabaseExt, SourceRoot, SourceRootId,
+    input::CrateName, CrateGraph, CrateId, Edition, Env, FileId, FilePosition, SourceDatabaseExt,
+    SourceRoot, SourceRootId,
 };
 
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
@@ -75,21 +74,32 @@ pub const WORKSPACE: SourceRootId = SourceRootId(0);
 pub trait WithFixture: Default + SourceDatabaseExt + 'static {
     fn with_single_file(text: &str) -> (Self, FileId) {
         let mut db = Self::default();
-        let file_id = with_single_file(&mut db, text);
-        (db, file_id)
+        let (_, files) = with_files(&mut db, text);
+        assert_eq!(files.len(), 1);
+        (db, files[0])
     }
 
     fn with_files(ra_fixture: &str) -> Self {
         let mut db = Self::default();
-        let pos = with_files(&mut db, ra_fixture);
+        let (pos, _) = with_files(&mut db, ra_fixture);
         assert!(pos.is_none());
         db
     }
 
     fn with_position(ra_fixture: &str) -> (Self, FilePosition) {
+        let (db, file_id, range_or_offset) = Self::with_range_or_offset(ra_fixture);
+        let offset = match range_or_offset {
+            RangeOrOffset::Range(_) => panic!(),
+            RangeOrOffset::Offset(it) => it,
+        };
+        (db, FilePosition { file_id, offset })
+    }
+
+    fn with_range_or_offset(ra_fixture: &str) -> (Self, FileId, RangeOrOffset) {
         let mut db = Self::default();
-        let pos = with_files(&mut db, ra_fixture);
-        (db, pos.unwrap())
+        let (pos, _) = with_files(&mut db, ra_fixture);
+        let (file_id, range_or_offset) = pos.unwrap();
+        (db, file_id, range_or_offset)
     }
 
     fn test_crate(&self) -> CrateId {
@@ -103,119 +113,64 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
 
 impl<DB: SourceDatabaseExt + Default + 'static> WithFixture for DB {}
 
-fn with_single_file(db: &mut dyn SourceDatabaseExt, ra_fixture: &str) -> FileId {
-    let file_id = FileId(0);
-    let rel_path: RelativePathBuf = "/main.rs".into();
-
-    let mut source_root = SourceRoot::new_local();
-    source_root.insert_file(rel_path.clone(), file_id);
-
-    let fixture = parse_single_fixture(ra_fixture);
-
-    let crate_graph = if let Some(entry) = fixture {
-        let meta = match ParsedMeta::from(&entry.meta) {
-            ParsedMeta::File(it) => it,
-            _ => panic!("with_single_file only support file meta"),
-        };
-
-        let mut crate_graph = CrateGraph::default();
-        crate_graph.add_crate_root(
-            file_id,
-            meta.edition,
-            meta.krate.map(|name| {
-                CrateName::new(&name).expect("Fixture crate name should not contain dashes")
-            }),
-            meta.cfg,
-            meta.env,
-            Default::default(),
-            Default::default(),
-        );
-        crate_graph
-    } else {
-        let mut crate_graph = CrateGraph::default();
-        crate_graph.add_crate_root(
-            file_id,
-            Edition::Edition2018,
-            None,
-            CfgOptions::default(),
-            Env::default(),
-            Default::default(),
-            Default::default(),
-        );
-        crate_graph
-    };
-
-    db.set_file_text(file_id, Arc::new(ra_fixture.to_string()));
-    db.set_file_relative_path(file_id, rel_path);
-    db.set_file_source_root(file_id, WORKSPACE);
-    db.set_source_root(WORKSPACE, Arc::new(source_root));
-    db.set_crate_graph(Arc::new(crate_graph));
-
-    file_id
-}
-
-fn with_files(db: &mut dyn SourceDatabaseExt, fixture: &str) -> Option<FilePosition> {
-    let fixture = parse_fixture(fixture);
+fn with_files(
+    db: &mut dyn SourceDatabaseExt,
+    fixture: &str,
+) -> (Option<(FileId, RangeOrOffset)>, Vec<FileId>) {
+    let fixture = Fixture::parse(fixture);
 
+    let mut files = Vec::new();
     let mut crate_graph = CrateGraph::default();
     let mut crates = FxHashMap::default();
     let mut crate_deps = Vec::new();
     let mut default_crate_root: Option<FileId> = None;
 
-    let mut source_root = SourceRoot::new_local();
-    let mut source_root_id = WORKSPACE;
-    let mut source_root_prefix: RelativePathBuf = "/".into();
+    let mut file_set = FileSet::default();
+    let source_root_id = WORKSPACE;
+    let source_root_prefix = "/".to_string();
     let mut file_id = FileId(0);
 
     let mut file_position = None;
 
-    for entry in fixture.iter() {
-        let meta = match ParsedMeta::from(&entry.meta) {
-            ParsedMeta::Root { path } => {
-                let source_root = std::mem::replace(&mut source_root, SourceRoot::new_local());
-                db.set_source_root(source_root_id, Arc::new(source_root));
-                source_root_id.0 += 1;
-                source_root_prefix = path;
-                continue;
-            }
-            ParsedMeta::File(it) => it,
+    for entry in fixture {
+        let text = if entry.text.contains(CURSOR_MARKER) {
+            let (range_or_offset, text) = extract_range_or_offset(&entry.text);
+            assert!(file_position.is_none());
+            file_position = Some((file_id, range_or_offset));
+            text.to_string()
+        } else {
+            entry.text.clone()
         };
+
+        let meta = FileMeta::from(entry);
         assert!(meta.path.starts_with(&source_root_prefix));
 
         if let Some(krate) = meta.krate {
             let crate_id = crate_graph.add_crate_root(
                 file_id,
                 meta.edition,
-                Some(CrateName::new(&krate).unwrap()),
+                Some(krate.clone()),
                 meta.cfg,
                 meta.env,
                 Default::default(),
-                Default::default(),
             );
-            let prev = crates.insert(krate.clone(), crate_id);
+            let crate_name = CrateName::new(&krate).unwrap();
+            let prev = crates.insert(crate_name.clone(), crate_id);
             assert!(prev.is_none());
             for dep in meta.deps {
-                crate_deps.push((krate.clone(), dep))
+                let dep = CrateName::new(&dep).unwrap();
+                crate_deps.push((crate_name.clone(), dep))
             }
         } else if meta.path == "/main.rs" || meta.path == "/lib.rs" {
             assert!(default_crate_root.is_none());
             default_crate_root = Some(file_id);
         }
 
-        let text = if entry.text.contains(CURSOR_MARKER) {
-            let (offset, text) = extract_offset(&entry.text);
-            assert!(file_position.is_none());
-            file_position = Some(FilePosition { file_id, offset });
-            text.to_string()
-        } else {
-            entry.text.to_string()
-        };
-
         db.set_file_text(file_id, Arc::new(text));
-        db.set_file_relative_path(file_id, meta.path.clone());
         db.set_file_source_root(file_id, source_root_id);
-        source_root.insert_file(meta.path, file_id);
-
+        let path = VfsPath::new_virtual_path(meta.path);
+        file_set.insert(file_id, path.into());
+        files.push(file_id);
         file_id.0 += 1;
     }
 
@@ -228,7 +183,6 @@ fn with_files(db: &mut dyn SourceDatabaseExt, fixture: &str) -> Option<FilePosit
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
     } else {
         for (from, to) in crate_deps {
@@ -238,19 +192,14 @@ fn with_files(db: &mut dyn SourceDatabaseExt, fixture: &str) -> Option<FilePosit
         }
     }
 
-    db.set_source_root(source_root_id, Arc::new(source_root));
+    db.set_source_root(source_root_id, Arc::new(SourceRoot::new_local(file_set)));
     db.set_crate_graph(Arc::new(crate_graph));
 
-    file_position
-}
-
-enum ParsedMeta {
-    Root { path: RelativePathBuf },
-    File(FileMeta),
+    (file_position, files)
 }
 
 struct FileMeta {
-    path: RelativePathBuf,
+    path: String,
     krate: Option<String>,
     deps: Vec<String>,
     cfg: CfgOptions,
@@ -258,25 +207,22 @@ struct FileMeta {
     env: Env,
 }
 
-impl From<&FixtureMeta> for ParsedMeta {
-    fn from(meta: &FixtureMeta) -> Self {
-        match meta {
-            FixtureMeta::Root { path } => {
-                // `Self::Root` causes a false warning: 'variant is never constructed: `Root` '
-                // see https://github.com/rust-lang/rust/issues/69018
-                ParsedMeta::Root { path: path.to_owned() }
-            }
-            FixtureMeta::File(f) => Self::File(FileMeta {
-                path: f.path.to_owned(),
-                krate: f.crate_name.to_owned(),
-                deps: f.deps.to_owned(),
-                cfg: f.cfg.to_owned(),
-                edition: f
-                    .edition
-                    .as_ref()
-                    .map_or(Edition::Edition2018, |v| Edition::from_str(&v).unwrap()),
-                env: Env::from(f.env.iter()),
-            }),
+impl From<Fixture> for FileMeta {
+    fn from(f: Fixture) -> FileMeta {
+        let mut cfg = CfgOptions::default();
+        f.cfg_atoms.iter().for_each(|it| cfg.insert_atom(it.into()));
+        f.cfg_key_values.iter().for_each(|(k, v)| cfg.insert_key_value(k.into(), v.into()));
+
+        FileMeta {
+            path: f.path,
+            krate: f.krate,
+            deps: f.deps,
+            cfg,
+            edition: f
+                .edition
+                .as_ref()
+                .map_or(Edition::Edition2018, |v| Edition::from_str(&v).unwrap()),
+            env: Env::from(f.env.iter()),
         }
     }
 }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index 4d2d3b48a..aaa492759 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -6,29 +6,15 @@
 //! actual IO. See `vfs` and `project_model` in the `rust-analyzer` crate for how
 //! actual IO is done and lowered to input.
 
-use std::{
-    fmt, ops,
-    path::{Path, PathBuf},
-    str::FromStr,
-    sync::Arc,
-};
+use std::{fmt, ops, str::FromStr, sync::Arc};
 
 use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
-use rustc_hash::FxHashMap;
-use rustc_hash::FxHashSet;
-
-use crate::{RelativePath, RelativePathBuf};
-use fmt::Display;
 use ra_tt::TokenExpander;
+use rustc_hash::{FxHashMap, FxHashSet};
+use vfs::file_set::FileSet;
 
-/// `FileId` is an integer which uniquely identifies a file. File paths are
-/// messy and system-dependent, so most of the code should work directly with
-/// `FileId`, without inspecting the path. The mapping between `FileId` and path
-/// and `SourceRoot` is constant. A file rename is represented as a pair of
-/// deletion/creation.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct FileId(pub u32);
+pub use vfs::FileId;
 
 /// Files are grouped into source roots. A source root is a directory on the
 /// file systems which is watched for changes. Typically it corresponds to a
@@ -47,27 +33,18 @@ pub struct SourceRoot {
     /// Libraries are considered mostly immutable, this assumption is used to
     /// optimize salsa's query structure
     pub is_library: bool,
-    files: FxHashMap<RelativePathBuf, FileId>,
+    pub(crate) file_set: FileSet,
 }
 
 impl SourceRoot {
-    pub fn new_local() -> SourceRoot {
-        SourceRoot { is_library: false, files: Default::default() }
-    }
-    pub fn new_library() -> SourceRoot {
-        SourceRoot { is_library: true, files: Default::default() }
-    }
-    pub fn insert_file(&mut self, path: RelativePathBuf, file_id: FileId) {
-        self.files.insert(path, file_id);
+    pub fn new_local(file_set: FileSet) -> SourceRoot {
+        SourceRoot { is_library: false, file_set }
     }
-    pub fn remove_file(&mut self, path: &RelativePath) {
-        self.files.remove(path);
+    pub fn new_library(file_set: FileSet) -> SourceRoot {
+        SourceRoot { is_library: true, file_set }
     }
-    pub fn walk(&self) -> impl Iterator<Item = FileId> + '_ {
-        self.files.values().copied()
-    }
-    pub fn file_by_relative_path(&self, path: &RelativePath) -> Option<FileId> {
-        self.files.get(path).copied()
+    pub fn iter(&self) -> impl Iterator<Item = FileId> + '_ {
+        self.file_set.iter()
     }
 }
 
@@ -90,7 +67,7 @@ pub struct CrateGraph {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct CrateId(pub u32);
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct CrateName(SmolStr);
 
 impl CrateName {
@@ -111,12 +88,19 @@ impl CrateName {
     }
 }
 
-impl Display for CrateName {
+impl fmt::Display for CrateName {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", self.0)
     }
 }
 
+impl ops::Deref for CrateName {
+    type Target = str;
+    fn deref(&self) -> &Self::Target {
+        &*self.0
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct ProcMacroId(pub u32);
 
@@ -140,10 +124,9 @@ pub struct CrateData {
     /// The name to display to the end user.
     /// This actual crate name can be different in a particular dependent crate
     /// or may even be missing for some cases, such as a dummy crate for the code snippet.
-    pub display_name: Option<CrateName>,
+    pub display_name: Option<String>,
     pub cfg_options: CfgOptions,
     pub env: Env,
-    pub extern_source: ExternSource,
     pub dependencies: Vec<Dependency>,
     pub proc_macro: Vec<ProcMacro>,
 }
@@ -154,26 +137,15 @@ pub enum Edition {
     Edition2015,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct ExternSourceId(pub u32);
-
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct Env {
     entries: FxHashMap<String, String>,
 }
 
-// FIXME: Redesign vfs for solve the following limitation ?
-// Note: Some env variables (e.g. OUT_DIR) are located outside of the
-// crate. We store a map to allow remap it to ExternSourceId
-#[derive(Default, Debug, Clone, PartialEq, Eq)]
-pub struct ExternSource {
-    extern_paths: FxHashMap<PathBuf, ExternSourceId>,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Dependency {
     pub crate_id: CrateId,
-    pub name: SmolStr,
+    pub name: CrateName,
 }
 
 impl CrateGraph {
@@ -181,10 +153,9 @@ impl CrateGraph {
         &mut self,
         file_id: FileId,
         edition: Edition,
-        display_name: Option<CrateName>,
+        display_name: Option<String>,
         cfg_options: CfgOptions,
         env: Env,
-        extern_source: ExternSource,
         proc_macro: Vec<(SmolStr, Arc<dyn ra_tt::TokenExpander>)>,
     ) -> CrateId {
         let proc_macro =
@@ -196,7 +167,6 @@ impl CrateGraph {
             display_name,
             cfg_options,
             env,
-            extern_source,
             proc_macro,
             dependencies: Vec::new(),
         };
@@ -215,7 +185,7 @@ impl CrateGraph {
         if self.dfs_find(from, to, &mut FxHashSet::default()) {
             return Err(CyclicDependenciesError);
         }
-        self.arena.get_mut(&from).unwrap().add_dep(name.0, to);
+        self.arena.get_mut(&from).unwrap().add_dep(name, to);
         Ok(())
     }
 
@@ -227,6 +197,23 @@ impl CrateGraph {
         self.arena.keys().copied()
     }
 
+    /// Returns an iterator over all transitive dependencies of the given crate.
+    pub fn transitive_deps(&self, of: CrateId) -> impl Iterator<Item = CrateId> + '_ {
+        let mut worklist = vec![of];
+        let mut deps = FxHashSet::default();
+
+        while let Some(krate) = worklist.pop() {
+            if !deps.insert(krate) {
+                continue;
+            }
+
+            worklist.extend(self[krate].dependencies.iter().map(|dep| dep.crate_id));
+        }
+
+        deps.remove(&of);
+        deps.into_iter()
+    }
+
     // FIXME: this only finds one crate with the given root; we could have multiple
     pub fn crate_id_for_crate_root(&self, file_id: FileId) -> Option<CrateId> {
         let (&crate_id, _) =
@@ -256,12 +243,12 @@ impl CrateGraph {
             return false;
         }
 
+        if target == from {
+            return true;
+        }
+
         for dep in &self[from].dependencies {
             let crate_id = dep.crate_id;
-            if crate_id == target {
-                return true;
-            }
-
             if self.dfs_find(target, crate_id, visited) {
                 return true;
             }
@@ -284,7 +271,7 @@ impl CrateId {
 }
 
 impl CrateData {
-    fn add_dep(&mut self, name: SmolStr, crate_id: CrateId) {
+    fn add_dep(&mut self, name: CrateName, crate_id: CrateId) {
         self.dependencies.push(Dependency { name, crate_id })
     }
 }
@@ -336,24 +323,6 @@ impl Env {
     }
 }
 
-impl ExternSource {
-    pub fn extern_path(&self, path: impl AsRef<Path>) -> Option<(ExternSourceId, RelativePathBuf)> {
-        let path = path.as_ref();
-        self.extern_paths.iter().find_map(|(root_path, id)| {
-            if let Ok(rel_path) = path.strip_prefix(root_path) {
-                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
-                Some((*id, rel_path))
-            } else {
-                None
-            }
-        })
-    }
-
-    pub fn set_extern_path(&mut self, root_path: &Path, root: ExternSourceId) {
-        self.extern_paths.insert(root_path.to_path_buf(), root);
-    }
-}
-
 #[derive(Debug)]
 pub struct ParseEditionError {
     invalid_input: String,
@@ -375,7 +344,7 @@ mod tests {
     use super::{CfgOptions, CrateGraph, CrateName, Dependency, Edition::Edition2018, Env, FileId};
 
     #[test]
-    fn it_should_panic_because_of_cycle_dependencies() {
+    fn detect_cyclic_dependency_indirect() {
         let mut graph = CrateGraph::default();
         let crate1 = graph.add_crate_root(
             FileId(1u32),
@@ -384,7 +353,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         let crate2 = graph.add_crate_root(
             FileId(2u32),
@@ -393,7 +361,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         let crate3 = graph.add_crate_root(
             FileId(3u32),
@@ -402,7 +369,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         assert!(graph.add_dep(crate1, CrateName::new("crate2").unwrap(), crate2).is_ok());
         assert!(graph.add_dep(crate2, CrateName::new("crate3").unwrap(), crate3).is_ok());
@@ -410,7 +376,7 @@ mod tests {
     }
 
     #[test]
-    fn it_works() {
+    fn detect_cyclic_dependency_direct() {
         let mut graph = CrateGraph::default();
         let crate1 = graph.add_crate_root(
             FileId(1u32),
@@ -419,7 +385,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         let crate2 = graph.add_crate_root(
             FileId(2u32),
@@ -428,6 +393,28 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
+        );
+        assert!(graph.add_dep(crate1, CrateName::new("crate2").unwrap(), crate2).is_ok());
+        assert!(graph.add_dep(crate2, CrateName::new("crate2").unwrap(), crate2).is_err());
+    }
+
+    #[test]
+    fn it_works() {
+        let mut graph = CrateGraph::default();
+        let crate1 = graph.add_crate_root(
+            FileId(1u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
+            Default::default(),
+        );
+        let crate2 = graph.add_crate_root(
+            FileId(2u32),
+            Edition2018,
+            None,
+            CfgOptions::default(),
+            Env::default(),
             Default::default(),
         );
         let crate3 = graph.add_crate_root(
@@ -437,7 +424,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         assert!(graph.add_dep(crate1, CrateName::new("crate2").unwrap(), crate2).is_ok());
         assert!(graph.add_dep(crate2, CrateName::new("crate3").unwrap(), crate3).is_ok());
@@ -453,7 +439,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         let crate2 = graph.add_crate_root(
             FileId(2u32),
@@ -462,14 +447,16 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         assert!(graph
             .add_dep(crate1, CrateName::normalize_dashes("crate-name-with-dashes"), crate2)
             .is_ok());
         assert_eq!(
             graph[crate1].dependencies,
-            vec![Dependency { crate_id: crate2, name: "crate_name_with_dashes".into() }]
+            vec![Dependency {
+                crate_id: crate2,
+                name: CrateName::new("crate_name_with_dashes").unwrap()
+            }]
         );
     }
 }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index fd4280de2..f25be24fe 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -7,16 +7,17 @@ use std::{panic, sync::Arc};
 
 use ra_prof::profile;
 use ra_syntax::{ast, Parse, SourceFile, TextRange, TextSize};
+use rustc_hash::FxHashSet;
 
 pub use crate::{
     cancellation::Canceled,
     input::{
-        CrateGraph, CrateId, CrateName, Dependency, Edition, Env, ExternSource, ExternSourceId,
-        FileId, ProcMacroId, SourceRoot, SourceRootId,
+        CrateData, CrateGraph, CrateId, CrateName, Dependency, Edition, Env, FileId, ProcMacroId,
+        SourceRoot, SourceRootId,
     },
 };
-pub use relative_path::{RelativePath, RelativePathBuf};
 pub use salsa;
+pub use vfs::{file_set::FileSet, VfsPath};
 
 #[macro_export]
 macro_rules! impl_intern_key {
@@ -78,7 +79,7 @@ pub struct FilePosition {
     pub offset: TextSize,
 }
 
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub struct FileRange {
     pub file_id: FileId,
     pub range: TextRange,
@@ -89,15 +90,13 @@ pub const DEFAULT_LRU_CAP: usize = 128;
 pub trait FileLoader {
     /// Text of the file.
     fn file_text(&self, file_id: FileId) -> Arc<String>;
-    fn resolve_relative_path(&self, anchor: FileId, relative_path: &RelativePath)
-        -> Option<FileId>;
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>>;
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId>;
+    /// Note that we intentionally accept a `&str` and not a `&Path` here. This
+    /// method exists to handle `#[path = "/some/path.rs"] mod foo;` and such,
+    /// so the input is guaranteed to be utf-8 string. One might be tempted to
+    /// introduce some kind of "utf-8 path with / separators", but that's a bad idea. Behold
+    /// `#[path = "C://no/way"]`
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId>;
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>>;
 }
 
 /// Database which stores all significant input facts: source code and project
@@ -113,8 +112,8 @@ pub trait SourceDatabase: CheckCanceled + FileLoader + std::fmt::Debug {
     fn crate_graph(&self) -> Arc<CrateGraph>;
 }
 
-fn parse_query(db: &impl SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
-    let _p = profile("parse_query");
+fn parse_query(db: &dyn SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
+    let _p = profile("parse_query").detail(|| format!("{:?}", file_id));
     let text = db.file_text(file_id);
     SourceFile::parse(&*text)
 }
@@ -126,8 +125,6 @@ pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
     fn file_text(&self, file_id: FileId) -> Arc<String>;
     /// Path to a file, relative to the root of its source root.
-    #[salsa::input]
-    fn file_relative_path(&self, file_id: FileId) -> RelativePathBuf;
     /// Source root of the file.
     #[salsa::input]
     fn file_source_root(&self, file_id: FileId) -> SourceRootId;
@@ -135,16 +132,18 @@ pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
     fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
 
-    fn source_root_crates(&self, id: SourceRootId) -> Arc<Vec<CrateId>>;
+    fn source_root_crates(&self, id: SourceRootId) -> Arc<FxHashSet<CrateId>>;
 }
 
-fn source_root_crates(
-    db: &(impl SourceDatabaseExt + SourceDatabase),
-    id: SourceRootId,
-) -> Arc<Vec<CrateId>> {
-    let root = db.source_root(id);
+fn source_root_crates(db: &dyn SourceDatabaseExt, id: SourceRootId) -> Arc<FxHashSet<CrateId>> {
     let graph = db.crate_graph();
-    let res = root.walk().filter_map(|it| graph.crate_id_for_crate_root(it)).collect::<Vec<_>>();
+    let res = graph
+        .iter()
+        .filter(|&krate| {
+            let root_file = graph[krate].root_file_id;
+            db.file_source_root(root_file) == id
+        })
+        .collect::<FxHashSet<_>>();
     Arc::new(res)
 }
 
@@ -155,33 +154,15 @@ impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         SourceDatabaseExt::file_text(self.0, file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        let path = {
-            let mut path = self.0.file_relative_path(anchor);
-            assert!(path.pop());
-            path.push(relative_path);
-            path.normalize()
-        };
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        // FIXME: this *somehow* should be platform agnostic...
         let source_root = self.0.file_source_root(anchor);
         let source_root = self.0.source_root(source_root);
-        source_root.file_by_relative_path(&path)
+        source_root.file_set.resolve_path(anchor, path)
     }
 
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         let source_root = self.0.file_source_root(file_id);
         self.0.source_root_crates(source_root)
     }
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        let source_root = self.0.source_root(SourceRootId(extern_id.0));
-        source_root.file_by_relative_path(&relative_path)
-    }
 }
diff --git a/crates/ra_flycheck/src/lib.rs b/crates/ra_flycheck/src/lib.rs
deleted file mode 100644
index 041e38a9f..000000000
--- a/crates/ra_flycheck/src/lib.rs
+++ /dev/null
@@ -1,302 +0,0 @@
-//! cargo_check provides the functionality needed to run `cargo check` or
-//! another compatible command (f.x. clippy) in a background thread and provide
-//! LSP diagnostics based on the output of the command.
-
-use std::{
-    io::{self, BufReader},
-    path::PathBuf,
-    process::{Command, Stdio},
-    time::Instant,
-};
-
-use cargo_metadata::Message;
-use crossbeam_channel::{never, select, unbounded, Receiver, RecvError, Sender};
-
-pub use cargo_metadata::diagnostic::{
-    Applicability, Diagnostic, DiagnosticLevel, DiagnosticSpan, DiagnosticSpanMacroExpansion,
-};
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum FlycheckConfig {
-    CargoCommand { command: String, all_targets: bool, all_features: bool, extra_args: Vec<String> },
-    CustomCommand { command: String, args: Vec<String> },
-}
-
-/// Flycheck wraps the shared state and communication machinery used for
-/// running `cargo check` (or other compatible command) and providing
-/// diagnostics based on the output.
-/// The spawned thread is shut down when this struct is dropped.
-#[derive(Debug)]
-pub struct Flycheck {
-    // XXX: drop order is significant
-    cmd_send: Sender<CheckCommand>,
-    handle: jod_thread::JoinHandle<()>,
-    pub task_recv: Receiver<CheckTask>,
-}
-
-impl Flycheck {
-    pub fn new(config: FlycheckConfig, workspace_root: PathBuf) -> Flycheck {
-        let (task_send, task_recv) = unbounded::<CheckTask>();
-        let (cmd_send, cmd_recv) = unbounded::<CheckCommand>();
-        let handle = jod_thread::spawn(move || {
-            FlycheckThread::new(config, workspace_root).run(&task_send, &cmd_recv);
-        });
-        Flycheck { task_recv, cmd_send, handle }
-    }
-
-    /// Schedule a re-start of the cargo check worker.
-    pub fn update(&self) {
-        self.cmd_send.send(CheckCommand::Update).unwrap();
-    }
-}
-
-#[derive(Debug)]
-pub enum CheckTask {
-    /// Request a clearing of all cached diagnostics from the check watcher
-    ClearDiagnostics,
-
-    /// Request adding a diagnostic with fixes included to a file
-    AddDiagnostic { workspace_root: PathBuf, diagnostic: Diagnostic },
-
-    /// Request check progress notification to client
-    Status(Status),
-}
-
-#[derive(Debug)]
-pub enum Status {
-    Being,
-    Progress(String),
-    End,
-}
-
-pub enum CheckCommand {
-    /// Request re-start of check thread
-    Update,
-}
-
-struct FlycheckThread {
-    config: FlycheckConfig,
-    workspace_root: PathBuf,
-    last_update_req: Option<Instant>,
-    // XXX: drop order is significant
-    message_recv: Receiver<CheckEvent>,
-    /// WatchThread exists to wrap around the communication needed to be able to
-    /// run `cargo check` without blocking. Currently the Rust standard library
-    /// doesn't provide a way to read sub-process output without blocking, so we
-    /// have to wrap sub-processes output handling in a thread and pass messages
-    /// back over a channel.
-    check_process: Option<jod_thread::JoinHandle<()>>,
-}
-
-impl FlycheckThread {
-    fn new(config: FlycheckConfig, workspace_root: PathBuf) -> FlycheckThread {
-        FlycheckThread {
-            config,
-            workspace_root,
-            last_update_req: None,
-            message_recv: never(),
-            check_process: None,
-        }
-    }
-
-    fn run(&mut self, task_send: &Sender<CheckTask>, cmd_recv: &Receiver<CheckCommand>) {
-        // If we rerun the thread, we need to discard the previous check results first
-        self.clean_previous_results(task_send);
-
-        loop {
-            select! {
-                recv(&cmd_recv) -> cmd => match cmd {
-                    Ok(cmd) => self.handle_command(cmd),
-                    Err(RecvError) => {
-                        // Command channel has closed, so shut down
-                        break;
-                    },
-                },
-                recv(self.message_recv) -> msg => match msg {
-                    Ok(msg) => self.handle_message(msg, task_send),
-                    Err(RecvError) => {
-                        // Watcher finished, replace it with a never channel to
-                        // avoid busy-waiting.
-                        self.message_recv = never();
-                        self.check_process = None;
-                    },
-                }
-            };
-
-            if self.should_recheck() {
-                self.last_update_req = None;
-                task_send.send(CheckTask::ClearDiagnostics).unwrap();
-                self.restart_check_process();
-            }
-        }
-    }
-
-    fn clean_previous_results(&self, task_send: &Sender<CheckTask>) {
-        task_send.send(CheckTask::ClearDiagnostics).unwrap();
-        task_send.send(CheckTask::Status(Status::End)).unwrap();
-    }
-
-    fn should_recheck(&mut self) -> bool {
-        if let Some(_last_update_req) = &self.last_update_req {
-            // We currently only request an update on save, as we need up to
-            // date source on disk for cargo check to do it's magic, so we
-            // don't really need to debounce the requests at this point.
-            return true;
-        }
-        false
-    }
-
-    fn handle_command(&mut self, cmd: CheckCommand) {
-        match cmd {
-            CheckCommand::Update => self.last_update_req = Some(Instant::now()),
-        }
-    }
-
-    fn handle_message(&self, msg: CheckEvent, task_send: &Sender<CheckTask>) {
-        match msg {
-            CheckEvent::Begin => {
-                task_send.send(CheckTask::Status(Status::Being)).unwrap();
-            }
-
-            CheckEvent::End => {
-                task_send.send(CheckTask::Status(Status::End)).unwrap();
-            }
-
-            CheckEvent::Msg(Message::CompilerArtifact(msg)) => {
-                task_send.send(CheckTask::Status(Status::Progress(msg.target.name))).unwrap();
-            }
-
-            CheckEvent::Msg(Message::CompilerMessage(msg)) => {
-                task_send
-                    .send(CheckTask::AddDiagnostic {
-                        workspace_root: self.workspace_root.clone(),
-                        diagnostic: msg.message,
-                    })
-                    .unwrap();
-            }
-
-            CheckEvent::Msg(Message::BuildScriptExecuted(_msg)) => {}
-            CheckEvent::Msg(Message::BuildFinished(_)) => {}
-            CheckEvent::Msg(Message::TextLine(_)) => {}
-            CheckEvent::Msg(Message::Unknown) => {}
-        }
-    }
-
-    fn restart_check_process(&mut self) {
-        // First, clear and cancel the old thread
-        self.message_recv = never();
-        self.check_process = None;
-
-        let mut cmd = match &self.config {
-            FlycheckConfig::CargoCommand { command, all_targets, all_features, extra_args } => {
-                let mut cmd = Command::new(ra_toolchain::cargo());
-                cmd.arg(command);
-                cmd.args(&["--workspace", "--message-format=json", "--manifest-path"])
-                    .arg(self.workspace_root.join("Cargo.toml"));
-                if *all_targets {
-                    cmd.arg("--all-targets");
-                }
-                if *all_features {
-                    cmd.arg("--all-features");
-                }
-                cmd.args(extra_args);
-                cmd
-            }
-            FlycheckConfig::CustomCommand { command, args } => {
-                let mut cmd = Command::new(command);
-                cmd.args(args);
-                cmd
-            }
-        };
-        cmd.current_dir(&self.workspace_root);
-
-        let (message_send, message_recv) = unbounded();
-        self.message_recv = message_recv;
-        self.check_process = Some(jod_thread::spawn(move || {
-            // If we trigger an error here, we will do so in the loop instead,
-            // which will break out of the loop, and continue the shutdown
-            let _ = message_send.send(CheckEvent::Begin);
-
-            let res = run_cargo(cmd, &mut |message| {
-                // Skip certain kinds of messages to only spend time on what's useful
-                match &message {
-                    Message::CompilerArtifact(artifact) if artifact.fresh => return true,
-                    Message::BuildScriptExecuted(_) => return true,
-                    Message::Unknown => return true,
-                    _ => {}
-                }
-
-                // if the send channel was closed, we want to shutdown
-                message_send.send(CheckEvent::Msg(message)).is_ok()
-            });
-
-            if let Err(err) = res {
-                // FIXME: make the `message_send` to be `Sender<Result<CheckEvent, CargoError>>`
-                // to display user-caused misconfiguration errors instead of just logging them here
-                log::error!("Cargo watcher failed {:?}", err);
-            }
-
-            // We can ignore any error here, as we are already in the progress
-            // of shutting down.
-            let _ = message_send.send(CheckEvent::End);
-        }))
-    }
-}
-
-enum CheckEvent {
-    Begin,
-    Msg(cargo_metadata::Message),
-    End,
-}
-
-fn run_cargo(
-    mut command: Command,
-    on_message: &mut dyn FnMut(cargo_metadata::Message) -> bool,
-) -> io::Result<()> {
-    let mut child =
-        command.stdout(Stdio::piped()).stderr(Stdio::null()).stdin(Stdio::null()).spawn()?;
-
-    // We manually read a line at a time, instead of using serde's
-    // stream deserializers, because the deserializer cannot recover
-    // from an error, resulting in it getting stuck, because we try to
-    // be resillient against failures.
-    //
-    // Because cargo only outputs one JSON object per line, we can
-    // simply skip a line if it doesn't parse, which just ignores any
-    // erroneus output.
-    let stdout = BufReader::new(child.stdout.take().unwrap());
-    let mut read_at_least_one_message = false;
-    for message in cargo_metadata::Message::parse_stream(stdout) {
-        let message = match message {
-            Ok(message) => message,
-            Err(err) => {
-                log::error!("Invalid json from cargo check, ignoring ({})", err);
-                continue;
-            }
-        };
-
-        read_at_least_one_message = true;
-
-        if !on_message(message) {
-            break;
-        }
-    }
-
-    // It is okay to ignore the result, as it only errors if the process is already dead
-    let _ = child.kill();
-
-    let exit_status = child.wait()?;
-    if !exit_status.success() && !read_at_least_one_message {
-        // FIXME: Read the stderr to display the reason, see `read2()` reference in PR comment:
-        // https://github.com/rust-analyzer/rust-analyzer/pull/3632#discussion_r395605298
-        return Err(io::Error::new(
-            io::ErrorKind::Other,
-            format!(
-                "the command produced no valid metadata (exit code: {:?}): {:?}",
-                exit_status, command
-            ),
-        ));
-    }
-
-    Ok(())
-}
diff --git a/crates/ra_fmt/Cargo.toml b/crates/ra_fmt/Cargo.toml
index e9d057afc..b4ef93f2b 100644
--- a/crates/ra_fmt/Cargo.toml
+++ b/crates/ra_fmt/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_fmt"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index ba7b39a19..c260bb193 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_hir"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -15,6 +16,7 @@ arrayvec = "0.5.1"
 
 itertools = "0.9.0"
 
+stdx = { path = "../stdx" }
 ra_syntax = { path = "../ra_syntax" }
 ra_db = { path = "../ra_db" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index e40aeffbc..9891b0785 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -9,6 +9,7 @@ use hir_def::{
     builtin_type::BuiltinType,
     docs::Documentation,
     expr::{BindingAnnotation, Pat, PatId},
+    import_map,
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
     type_ref::{Mutability, TypeRef},
@@ -24,22 +25,22 @@ use hir_expand::{
 use hir_ty::{
     autoderef,
     display::{HirDisplayError, HirFormatter},
-    expr::ExprValidator,
-    method_resolution, ApplicationTy, Canonical, InEnvironment, Substs, TraitEnvironment, Ty,
-    TyDefId, TypeCtor,
+    method_resolution, ApplicationTy, Canonical, GenericPredicate, InEnvironment, Substs,
+    TraitEnvironment, Ty, TyDefId, TypeCtor,
 };
-use ra_db::{CrateId, CrateName, Edition, FileId};
+use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
     AstNode,
 };
 use rustc_hash::FxHashSet;
+use stdx::impl_from;
 
 use crate::{
     db::{DefDatabase, HirDatabase},
     has_source::HasSource,
-    CallableDef, HirDisplay, InFile, Name,
+    CallableDefId, HirDisplay, InFile, Name,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -94,8 +95,25 @@ impl Crate {
         db.crate_graph()[self.id].edition
     }
 
-    pub fn display_name(self, db: &dyn HirDatabase) -> Option<CrateName> {
-        db.crate_graph()[self.id].display_name.as_ref().cloned()
+    pub fn display_name(self, db: &dyn HirDatabase) -> Option<String> {
+        db.crate_graph()[self.id].display_name.clone()
+    }
+
+    pub fn query_external_importables(
+        self,
+        db: &dyn DefDatabase,
+        query: &str,
+    ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+        import_map::search_dependencies(
+            db,
+            self.into(),
+            import_map::Query::new(query).anchor_end().case_sensitive().limit(40),
+        )
+        .into_iter()
+        .map(|item| match item {
+            ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
+            ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
+        })
     }
 
     pub fn all(db: &dyn HirDatabase) -> Vec<Crate> {
@@ -122,8 +140,8 @@ pub enum ModuleDef {
     TypeAlias(TypeAlias),
     BuiltinType(BuiltinType),
 }
-impl_froms!(
-    ModuleDef: Module,
+impl_from!(
+    Module,
     Function,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -132,6 +150,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     BuiltinType
+    for ModuleDef
 );
 
 impl ModuleDef {
@@ -168,10 +187,27 @@ impl ModuleDef {
 
         module.visibility_of(db, self)
     }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
+        match self {
+            ModuleDef::Adt(it) => Some(it.name(db)),
+            ModuleDef::Trait(it) => Some(it.name(db)),
+            ModuleDef::Function(it) => Some(it.name(db)),
+            ModuleDef::EnumVariant(it) => Some(it.name(db)),
+            ModuleDef::TypeAlias(it) => Some(it.name(db)),
+
+            ModuleDef::Module(it) => it.name(db),
+            ModuleDef::Const(it) => it.name(db),
+            ModuleDef::Static(it) => it.name(db),
+
+            ModuleDef::BuiltinType(it) => Some(it.as_name()),
+        }
+    }
 }
 
 pub use hir_def::{
-    attr::Attrs, item_scope::ItemInNs, visibility::Visibility, AssocItemId, AssocItemLoc,
+    attr::Attrs, item_scope::ItemInNs, item_tree::ItemTreeNode, visibility::Visibility,
+    AssocItemId, AssocItemLoc,
 };
 
 impl Module {
@@ -504,12 +540,12 @@ pub enum Adt {
     Union(Union),
     Enum(Enum),
 }
-impl_froms!(Adt: Struct, Union, Enum);
+impl_from!(Struct, Union, Enum for Adt);
 
 impl Adt {
     pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
         let subst = db.generic_defaults(self.into());
-        subst.iter().any(|ty| ty == &Ty::Unknown)
+        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
     }
 
     /// Turns this ADT into a type. Any type parameters of the ADT will be
@@ -547,7 +583,7 @@ pub enum VariantDef {
     Union(Union),
     EnumVariant(EnumVariant),
 }
-impl_froms!(VariantDef: Struct, Union, EnumVariant);
+impl_from!(Struct, Union, EnumVariant for VariantDef);
 
 impl VariantDef {
     pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
@@ -590,8 +626,7 @@ pub enum DefWithBody {
     Static(Static),
     Const(Const),
 }
-
-impl_froms!(DefWithBody: Function, Const, Static);
+impl_from!(Function, Const, Static for DefWithBody);
 
 impl DefWithBody {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
@@ -637,12 +672,12 @@ impl Function {
         db.function_data(self.id).params.clone()
     }
 
+    pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
+        db.function_data(self.id).is_unsafe
+    }
+
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
-        let _p = profile("Function::diagnostics");
-        let infer = db.infer(self.id.into());
-        infer.add_diagnostics(db, self.id, sink);
-        let mut validator = ExprValidator::new(self.id, infer, sink);
-        validator.validate_body(db);
+        hir_ty::diagnostics::validate_body(db, self.id.into(), sink)
     }
 }
 
@@ -735,7 +770,7 @@ pub struct TypeAlias {
 impl TypeAlias {
     pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
         let subst = db.generic_defaults(self.id.into());
-        subst.iter().any(|ty| ty == &Ty::Unknown)
+        subst.iter().any(|ty| &ty.value == &Ty::Unknown)
     }
 
     pub fn module(self, db: &dyn HirDatabase) -> Module {
@@ -834,7 +869,7 @@ where
     ID: Lookup<Data = AssocItemLoc<AST>>,
     DEF: From<ID>,
     CTOR: FnOnce(DEF) -> AssocItem,
-    AST: AstNode,
+    AST: ItemTreeNode,
 {
     match id.lookup(db.upcast()).container {
         AssocContainerId::TraitId(_) | AssocContainerId::ImplId(_) => Some(ctor(DEF::from(id))),
@@ -887,14 +922,15 @@ pub enum GenericDef {
     // consts can have type parameters from their parents (i.e. associated consts of traits)
     Const(Const),
 }
-impl_froms!(
-    GenericDef: Function,
+impl_from!(
+    Function,
     Adt(Struct, Enum, Union),
     Trait,
     TypeAlias,
     ImplDef,
     EnumVariant,
     Const
+    for GenericDef
 );
 
 impl GenericDef {
@@ -915,6 +951,16 @@ pub struct Local {
 }
 
 impl Local {
+    pub fn is_param(self, db: &dyn HirDatabase) -> bool {
+        let src = self.source(db);
+        match src.value {
+            Either::Left(bind_pat) => {
+                bind_pat.syntax().ancestors().any(|it| ast::Param::can_cast(it.kind()))
+            }
+            Either::Right(_self_param) => true,
+        }
+    }
+
     // FIXME: why is this an option? It shouldn't be?
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
         let body = db.body(self.parent.into());
@@ -995,7 +1041,10 @@ impl TypeParam {
         let local_idx = hir_ty::param_idx(db, self.id)?;
         let resolver = self.id.parent.resolver(db.upcast());
         let environment = TraitEnvironment::lower(db, &resolver);
-        params.get(local_idx).cloned().map(|ty| Type {
+        let ty = params.get(local_idx)?.clone();
+        let subst = Substs::type_params(db, self.id.parent);
+        let ty = ty.subst(&subst.prefix(local_idx));
+        Some(Type {
             krate: self.id.parent.module(db.upcast()).krate,
             ty: InEnvironment { value: ty, environment },
         })
@@ -1010,12 +1059,14 @@ pub struct ImplDef {
 
 impl ImplDef {
     pub fn all_in_crate(db: &dyn HirDatabase, krate: Crate) -> Vec<ImplDef> {
-        let impls = db.impls_in_crate(krate.id);
-        impls.all_impls().map(Self::from).collect()
+        let inherent = db.inherent_impls_in_crate(krate.id);
+        let trait_ = db.trait_impls_in_crate(krate.id);
+
+        inherent.all_impls().chain(trait_.all_impls()).map(Self::from).collect()
     }
     pub fn for_trait(db: &dyn HirDatabase, krate: Crate, trait_: Trait) -> Vec<ImplDef> {
-        let impls = db.impls_in_crate(krate.id);
-        impls.lookup_impl_defs_for_trait(trait_.id).map(Self::from).collect()
+        let impls = db.trait_impls_in_crate(krate.id);
+        impls.for_trait(trait_.id).map(Self::from).collect()
     }
 
     pub fn target_trait(self, db: &dyn HirDatabase) -> Option<TypeRef> {
@@ -1144,7 +1195,7 @@ impl Type {
             None => return false,
         };
 
-        let canonical_ty = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical_ty = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
         method_resolution::implements_trait(
             &canonical_ty,
             db,
@@ -1168,14 +1219,14 @@ impl Type {
                 self.ty.environment.clone(),
                 hir_ty::Obligation::Trait(trait_ref),
             ),
-            num_vars: 0,
+            kinds: Arc::new([]),
         };
 
         db.trait_solve(self.krate, goal).is_some()
     }
 
     // FIXME: this method is broken, as it doesn't take closures into account.
-    pub fn as_callable(&self) -> Option<CallableDef> {
+    pub fn as_callable(&self) -> Option<CallableDefId> {
         Some(self.ty.value.as_callable()?.0)
     }
 
@@ -1190,6 +1241,10 @@ impl Type {
         )
     }
 
+    pub fn is_raw_ptr(&self) -> bool {
+        matches!(&self.ty.value, Ty::Apply(ApplicationTy { ctor: TypeCtor::RawPtr(..), .. }))
+    }
+
     pub fn contains_unknown(&self) -> bool {
         return go(&self.ty.value);
 
@@ -1239,7 +1294,7 @@ impl Type {
     pub fn autoderef<'a>(&'a self, db: &'a dyn HirDatabase) -> impl Iterator<Item = Type> + 'a {
         // There should be no inference vars in types passed here
         // FIXME check that?
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
         let environment = self.ty.environment.clone();
         let ty = InEnvironment { value: canonical, environment };
         autoderef(db, Some(self.krate), ty)
@@ -1256,10 +1311,10 @@ impl Type {
         mut callback: impl FnMut(AssocItem) -> Option<T>,
     ) -> Option<T> {
         for krate in self.ty.value.def_crates(db, krate.id)? {
-            let impls = db.impls_in_crate(krate);
+            let impls = db.inherent_impls_in_crate(krate);
 
-            for impl_def in impls.lookup_impl_defs(&self.ty.value) {
-                for &item in db.impl_data(impl_def).items.iter() {
+            for impl_def in impls.for_self_ty(&self.ty.value) {
+                for &item in db.impl_data(*impl_def).items.iter() {
                     if let Some(result) = callback(item.into()) {
                         return Some(result);
                     }
@@ -1280,7 +1335,7 @@ impl Type {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
 
         let env = self.ty.environment.clone();
         let krate = krate.id;
@@ -1311,7 +1366,7 @@ impl Type {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), kinds: Arc::new([]) };
 
         let env = self.ty.environment.clone();
         let krate = krate.id;
@@ -1333,6 +1388,27 @@ impl Type {
         Some(adt.into())
     }
 
+    pub fn as_dyn_trait(&self) -> Option<Trait> {
+        self.ty.value.dyn_trait().map(Into::into)
+    }
+
+    pub fn as_impl_traits(&self, db: &dyn HirDatabase) -> Option<Vec<Trait>> {
+        self.ty.value.impl_trait_bounds(db).map(|it| {
+            it.into_iter()
+                .filter_map(|pred| match pred {
+                    hir_ty::GenericPredicate::Implemented(trait_ref) => {
+                        Some(Trait::from(trait_ref.trait_))
+                    }
+                    _ => None,
+                })
+                .collect()
+        })
+    }
+
+    pub fn as_associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<Trait> {
+        self.ty.value.associated_type_parent_trait(db).map(Into::into)
+    }
+
     // FIXME: provide required accessors such that it becomes implementable from outside.
     pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
         match (&self.ty.value, &other.ty.value) {
@@ -1354,6 +1430,80 @@ impl Type {
             ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
         }
     }
+
+    pub fn walk(&self, db: &dyn HirDatabase, mut cb: impl FnMut(Type)) {
+        // TypeWalk::walk for a Ty at first visits parameters and only after that the Ty itself.
+        // We need a different order here.
+
+        fn walk_substs(
+            db: &dyn HirDatabase,
+            type_: &Type,
+            substs: &Substs,
+            cb: &mut impl FnMut(Type),
+        ) {
+            for ty in substs.iter() {
+                walk_type(db, &type_.derived(ty.clone()), cb);
+            }
+        }
+
+        fn walk_bounds(
+            db: &dyn HirDatabase,
+            type_: &Type,
+            bounds: &[GenericPredicate],
+            cb: &mut impl FnMut(Type),
+        ) {
+            for pred in bounds {
+                match pred {
+                    GenericPredicate::Implemented(trait_ref) => {
+                        cb(type_.clone());
+                        walk_substs(db, type_, &trait_ref.substs, cb);
+                    }
+                    _ => (),
+                }
+            }
+        }
+
+        fn walk_type(db: &dyn HirDatabase, type_: &Type, cb: &mut impl FnMut(Type)) {
+            let ty = type_.ty.value.strip_references();
+            match ty {
+                Ty::Apply(ApplicationTy { ctor, parameters }) => {
+                    match ctor {
+                        TypeCtor::Adt(_) => {
+                            cb(type_.derived(ty.clone()));
+                        }
+                        TypeCtor::AssociatedType(_) => {
+                            if let Some(_) = ty.associated_type_parent_trait(db) {
+                                cb(type_.derived(ty.clone()));
+                            }
+                        }
+                        _ => (),
+                    }
+
+                    // adt params, tuples, etc...
+                    walk_substs(db, type_, parameters, cb);
+                }
+                Ty::Opaque(opaque_ty) => {
+                    if let Some(bounds) = ty.impl_trait_bounds(db) {
+                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
+                    }
+
+                    walk_substs(db, type_, &opaque_ty.parameters, cb);
+                }
+                Ty::Placeholder(_) => {
+                    if let Some(bounds) = ty.impl_trait_bounds(db) {
+                        walk_bounds(db, &type_.derived(ty.clone()), &bounds, cb);
+                    }
+                }
+                Ty::Dyn(bounds) => {
+                    walk_bounds(db, &type_.derived(ty.clone()), bounds.as_ref(), cb);
+                }
+
+                _ => (),
+            }
+        }
+
+        walk_type(db, self, &mut cb);
+    }
 }
 
 impl HirDisplay for Type {
@@ -1421,8 +1571,8 @@ pub enum AttrDef {
     MacroDef(MacroDef),
 }
 
-impl_froms!(
-    AttrDef: Module,
+impl_from!(
+    Module,
     Field,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -1432,6 +1582,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     MacroDef
+    for AttrDef
 );
 
 pub trait HasAttrs {
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index ec931b34f..1ad92a1f8 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -3,11 +3,11 @@
 pub use hir_def::db::{
     AttrsQuery, BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQueryQuery,
     CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery,
-    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternConstQuery,
-    InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery, InternImplQuery,
-    InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery, InternUnionQuery,
-    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery, StructDataQuery,
-    TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
+    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery,
+    InternConstQuery, InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery,
+    InternImplQuery, InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery,
+    InternUnionQuery, ItemTreeQuery, LangItemQuery, ModuleLangItemsQuery, StaticDataQuery,
+    StructDataQuery, TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternEagerExpansionQuery, InternMacroQuery,
@@ -16,10 +16,10 @@ pub use hir_expand::db::{
 pub use hir_ty::db::{
     AssociatedTyDataQuery, AssociatedTyValueQuery, CallableItemSignatureQuery, FieldTypesQuery,
     GenericDefaultsQuery, GenericPredicatesForParamQuery, GenericPredicatesQuery, HirDatabase,
-    HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery, ImplsForTraitQuery,
-    ImplsInCrateQuery, InferQueryQuery, InternAssocTyValueQuery, InternChalkImplQuery,
-    InternTypeCtorQuery, InternTypeParamIdQuery, StructDatumQuery, TraitDatumQuery,
-    TraitSolveQuery, TyQuery, ValueTyQuery,
+    HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery, InferQueryQuery,
+    InherentImplsInCrateQuery, InternTypeParamIdQuery, ReturnTypeImplTraitsQuery, StructDatumQuery,
+    TraitDatumQuery, TraitImplsInCrateQuery, TraitImplsInDepsQuery, TraitSolveQuery, TyQuery,
+    ValueTyQuery,
 };
 
 #[test]
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index c82883d0c..11a0ecb8b 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,4 +1,6 @@
 //! FIXME: write short doc here
 pub use hir_def::diagnostics::UnresolvedModule;
 pub use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
-pub use hir_ty::diagnostics::{MissingFields, MissingMatchArms, MissingOkInTailExpr, NoSuchField};
+pub use hir_ty::diagnostics::{
+    MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, NoSuchField,
+};
diff --git a/crates/ra_hir/src/has_source.rs b/crates/ra_hir/src/has_source.rs
index 63b8fd369..76c32fc17 100644
--- a/crates/ra_hir/src/has_source.rs
+++ b/crates/ra_hir/src/has_source.rs
@@ -2,7 +2,7 @@
 
 use either::Either;
 use hir_def::{
-    nameres::ModuleSource,
+    nameres::{ModuleOrigin, ModuleSource},
     src::{HasChildSource, HasSource as _},
     Lookup, VariantId,
 };
@@ -29,6 +29,14 @@ impl Module {
         def_map[self.id.local_id].definition_source(db.upcast())
     }
 
+    pub fn is_mod_rs(self, db: &dyn HirDatabase) -> bool {
+        let def_map = db.crate_def_map(self.id.krate);
+        match def_map[self.id.local_id].origin {
+            ModuleOrigin::File { is_mod_rs, .. } => is_mod_rs,
+            _ => false,
+        }
+    }
+
     /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
     /// `None` for the crate root.
     pub fn declaration_source(self, db: &dyn HirDatabase) -> Option<InFile<ast::Module>> {
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3364a822f..cf7134923 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -19,25 +19,6 @@
 
 #![recursion_limit = "512"]
 
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident $(($($sv:ident),*))?),*$(,)?) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-            $($(
-                impl From<$sv> for $e {
-                    fn from(it: $sv) -> $e {
-                        $e::$v($v::$sv(it))
-                    }
-                }
-            )*)?
-        )*
-    }
-}
-
 mod semantics;
 pub mod db;
 mod source_analyzer;
@@ -74,4 +55,4 @@ pub use hir_expand::{
     hygiene::Hygiene, name::Name, HirFileId, InFile, MacroCallId, MacroCallLoc, MacroDefId,
     MacroFile, Origin,
 };
-pub use hir_ty::{display::HirDisplay, CallableDef};
+pub use hir_ty::{display::HirDisplay, CallableDefId};
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 7c1f79f27..155b666d7 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -6,9 +6,9 @@ use std::{cell::RefCell, fmt, iter::successors};
 
 use hir_def::{
     resolver::{self, HasResolver, Resolver},
-    AsMacroCall, TraitId,
+    AsMacroCall, TraitId, VariantId,
 };
-use hir_expand::{hygiene::Hygiene, ExpansionInfo};
+use hir_expand::{diagnostics::AstDiagnostic, hygiene::Hygiene, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
 use itertools::Itertools;
 use ra_db::{FileId, FileRange};
@@ -25,7 +25,7 @@ use crate::{
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, resolve_hir_path_qualifier, SourceAnalyzer},
     AssocItem, Field, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module, ModuleDef,
-    Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam,
+    Name, Origin, Path, ScopeDef, Trait, Type, TypeAlias, TypeParam, VariantDef,
 };
 use resolver::TypeNs;
 
@@ -83,6 +83,11 @@ impl PathResolution {
 /// Primary API to get semantic information, like types, from syntax trees.
 pub struct Semantics<'db, DB> {
     pub db: &'db DB,
+    imp: SemanticsImpl<'db>,
+}
+
+pub struct SemanticsImpl<'db> {
+    pub db: &'db dyn HirDatabase,
     s2d_cache: RefCell<SourceToDefCache>,
     cache: RefCell<FxHashMap<SyntaxNode, HirFileId>>,
 }
@@ -95,16 +100,187 @@ impl<DB> fmt::Debug for Semantics<'_, DB> {
 
 impl<'db, DB: HirDatabase> Semantics<'db, DB> {
     pub fn new(db: &DB) -> Semantics<DB> {
-        Semantics { db, s2d_cache: Default::default(), cache: Default::default() }
+        let impl_ = SemanticsImpl::new(db);
+        Semantics { db, imp: impl_ }
     }
 
     pub fn parse(&self, file_id: FileId) -> ast::SourceFile {
+        self.imp.parse(file_id)
+    }
+
+    pub fn ast<T: AstDiagnostic + Diagnostic>(&self, d: &T) -> <T as AstDiagnostic>::AST {
+        let file_id = d.source().file_id;
+        let root = self.db.parse_or_expand(file_id).unwrap();
+        self.imp.cache(root, file_id);
+        d.ast(self.db.upcast())
+    }
+
+    pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
+        self.imp.expand(macro_call)
+    }
+
+    pub fn expand_hypothetical(
+        &self,
+        actual_macro_call: &ast::MacroCall,
+        hypothetical_args: &ast::TokenTree,
+        token_to_map: SyntaxToken,
+    ) -> Option<(SyntaxNode, SyntaxToken)> {
+        self.imp.expand_hypothetical(actual_macro_call, hypothetical_args, token_to_map)
+    }
+
+    pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        self.imp.descend_into_macros(token)
+    }
+
+    pub fn descend_node_at_offset<N: ast::AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        self.imp.descend_node_at_offset(node, offset).find_map(N::cast)
+    }
+
+    pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
+        self.imp.original_range(node)
+    }
+
+    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+        self.imp.diagnostics_range(diagnostics)
+    }
+
+    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
+        self.imp.ancestors_with_macros(node)
+    }
+
+    pub fn ancestors_at_offset_with_macros(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
+        self.imp.ancestors_at_offset_with_macros(node, offset)
+    }
+
+    /// Find a AstNode by offset inside SyntaxNode, if it is inside *Macrofile*,
+    /// search up until it is of the target AstNode type
+    pub fn find_node_at_offset_with_macros<N: AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        self.imp.ancestors_at_offset_with_macros(node, offset).find_map(N::cast)
+    }
+
+    /// Find a AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
+    /// descend it and find again
+    pub fn find_node_at_offset_with_descend<N: AstNode>(
+        &self,
+        node: &SyntaxNode,
+        offset: TextSize,
+    ) -> Option<N> {
+        if let Some(it) = find_node_at_offset(&node, offset) {
+            return Some(it);
+        }
+
+        self.imp.descend_node_at_offset(node, offset).find_map(N::cast)
+    }
+
+    pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
+        self.imp.type_of_expr(expr)
+    }
+
+    pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
+        self.imp.type_of_pat(pat)
+    }
+
+    pub fn type_of_self(&self, param: &ast::SelfParam) -> Option<Type> {
+        self.imp.type_of_self(param)
+    }
+
+    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+        self.imp.resolve_method_call(call)
+    }
+
+    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
+        self.imp.resolve_field(field)
+    }
+
+    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<(Field, Option<Local>)> {
+        self.imp.resolve_record_field(field)
+    }
+
+    pub fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
+        self.imp.resolve_record_field_pat(field)
+    }
+
+    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
+        self.imp.resolve_macro_call(macro_call)
+    }
+
+    pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
+        self.imp.resolve_path(path)
+    }
+
+    pub fn resolve_variant(&self, record_lit: ast::RecordLit) -> Option<VariantDef> {
+        self.imp.resolve_variant(record_lit).map(VariantDef::from)
+    }
+
+    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
+        self.imp.lower_path(path)
+    }
+
+    pub fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
+        self.imp.resolve_bind_pat_to_const(pat)
+    }
+
+    // FIXME: use this instead?
+    // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
+
+    pub fn record_literal_missing_fields(&self, literal: &ast::RecordLit) -> Vec<(Field, Type)> {
+        self.imp.record_literal_missing_fields(literal)
+    }
+
+    pub fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
+        self.imp.record_pattern_missing_fields(pattern)
+    }
+
+    pub fn to_def<T: ToDef>(&self, src: &T) -> Option<T::Def> {
+        let src = self.imp.find_file(src.syntax().clone()).with_value(src).cloned();
+        T::to_def(&self.imp, src)
+    }
+
+    pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+        self.imp.to_module_def(file)
+    }
+
+    pub fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db> {
+        self.imp.scope(node)
+    }
+
+    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db> {
+        self.imp.scope_at_offset(node, offset)
+    }
+
+    pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db> {
+        self.imp.scope_for_def(def)
+    }
+
+    pub fn assert_contains_node(&self, node: &SyntaxNode) {
+        self.imp.assert_contains_node(node)
+    }
+}
+
+impl<'db> SemanticsImpl<'db> {
+    fn new(db: &'db dyn HirDatabase) -> Self {
+        Self { db, s2d_cache: Default::default(), cache: Default::default() }
+    }
+
+    fn parse(&self, file_id: FileId) -> ast::SourceFile {
         let tree = self.db.parse(file_id).tree();
         self.cache(tree.syntax().clone(), file_id.into());
         tree
     }
 
-    pub fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
+    fn expand(&self, macro_call: &ast::MacroCall) -> Option<SyntaxNode> {
         let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
         let file_id = sa.expand(self.db, macro_call)?;
@@ -113,7 +289,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         Some(node)
     }
 
-    pub fn expand_hypothetical(
+    fn expand_hypothetical(
         &self,
         actual_macro_call: &ast::MacroCall,
         hypothetical_args: &ast::TokenTree,
@@ -122,12 +298,19 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         let macro_call =
             self.find_file(actual_macro_call.syntax().clone()).with_value(actual_macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
-        let macro_call_id = macro_call
-            .as_call_id(self.db, |path| sa.resolver.resolve_path_as_macro(self.db, &path))?;
-        hir_expand::db::expand_hypothetical(self.db, macro_call_id, hypothetical_args, token_to_map)
-    }
-
-    pub fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
+        let krate = sa.resolver.krate()?;
+        let macro_call_id = macro_call.as_call_id(self.db.upcast(), krate, |path| {
+            sa.resolver.resolve_path_as_macro(self.db.upcast(), &path)
+        })?;
+        hir_expand::db::expand_hypothetical(
+            self.db.upcast(),
+            macro_call_id,
+            hypothetical_args,
+            token_to_map,
+        )
+    }
+
+    fn descend_into_macros(&self, token: SyntaxToken) -> SyntaxToken {
         let parent = token.parent();
         let parent = self.find_file(parent);
         let sa = self.analyze2(parent.as_ref(), None);
@@ -139,7 +322,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
                 return None;
             }
             let file_id = sa.expand(self.db, token.with_value(&macro_call))?;
-            let token = file_id.expansion_info(self.db)?.map_token_down(token.as_ref())?;
+            let token = file_id.expansion_info(self.db.upcast())?.map_token_down(token.as_ref())?;
 
             self.cache(find_root(&token.value.parent()), token.file_id);
 
@@ -151,35 +334,36 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         token.value
     }
 
-    pub fn descend_node_at_offset<N: ast::AstNode>(
+    fn descend_node_at_offset(
         &self,
         node: &SyntaxNode,
         offset: TextSize,
-    ) -> Option<N> {
+    ) -> impl Iterator<Item = SyntaxNode> + '_ {
         // Handle macro token cases
         node.token_at_offset(offset)
             .map(|token| self.descend_into_macros(token))
-            .find_map(|it| self.ancestors_with_macros(it.parent()).find_map(N::cast))
+            .map(|it| self.ancestors_with_macros(it.parent()))
+            .flatten()
     }
 
-    pub fn original_range(&self, node: &SyntaxNode) -> FileRange {
+    fn original_range(&self, node: &SyntaxNode) -> FileRange {
         let node = self.find_file(node.clone());
         original_range(self.db, node.as_ref())
     }
 
-    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+    fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
         let src = diagnostics.source();
         let root = self.db.parse_or_expand(src.file_id).unwrap();
         let node = src.value.to_node(&root);
         original_range(self.db, src.with_value(&node))
     }
 
-    pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
+    fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
         let node = self.find_file(node);
-        node.ancestors_with_macros(self.db).map(|it| it.value)
+        node.ancestors_with_macros(self.db.upcast()).map(|it| it.value)
     }
 
-    pub fn ancestors_at_offset_with_macros(
+    fn ancestors_at_offset_with_macros(
         &self,
         node: &SyntaxNode,
         offset: TextSize,
@@ -189,116 +373,93 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
             .kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len())
     }
 
-    /// Find a AstNode by offset inside SyntaxNode, if it is inside *Macrofile*,
-    /// search up until it is of the target AstNode type
-    pub fn find_node_at_offset_with_macros<N: AstNode>(
-        &self,
-        node: &SyntaxNode,
-        offset: TextSize,
-    ) -> Option<N> {
-        self.ancestors_at_offset_with_macros(node, offset).find_map(N::cast)
+    fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
+        self.analyze(expr.syntax()).type_of_expr(self.db, &expr)
     }
 
-    /// Find a AstNode by offset inside SyntaxNode, if it is inside *MacroCall*,
-    /// descend it and find again
-    pub fn find_node_at_offset_with_descend<N: AstNode>(
-        &self,
-        node: &SyntaxNode,
-        offset: TextSize,
-    ) -> Option<N> {
-        if let Some(it) = find_node_at_offset(&node, offset) {
-            return Some(it);
-        }
-        self.descend_node_at_offset(&node, offset)
+    fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
+        self.analyze(pat.syntax()).type_of_pat(self.db, &pat)
     }
 
-    pub fn type_of_expr(&self, expr: &ast::Expr) -> Option<Type> {
-        self.analyze(expr.syntax()).type_of(self.db, &expr)
+    fn type_of_self(&self, param: &ast::SelfParam) -> Option<Type> {
+        self.analyze(param.syntax()).type_of_self(self.db, &param)
     }
 
-    pub fn type_of_pat(&self, pat: &ast::Pat) -> Option<Type> {
-        self.analyze(pat.syntax()).type_of_pat(self.db, &pat)
-    }
-
-    pub fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
+    fn resolve_method_call(&self, call: &ast::MethodCallExpr) -> Option<Function> {
         self.analyze(call.syntax()).resolve_method_call(self.db, call)
     }
 
-    pub fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
+    fn resolve_field(&self, field: &ast::FieldExpr) -> Option<Field> {
         self.analyze(field.syntax()).resolve_field(self.db, field)
     }
 
-    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<(Field, Option<Local>)> {
+    fn resolve_record_field(&self, field: &ast::RecordField) -> Option<(Field, Option<Local>)> {
         self.analyze(field.syntax()).resolve_record_field(self.db, field)
     }
 
-    pub fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
+    fn resolve_record_field_pat(&self, field: &ast::RecordFieldPat) -> Option<Field> {
         self.analyze(field.syntax()).resolve_record_field_pat(self.db, field)
     }
 
-    pub fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
+    fn resolve_macro_call(&self, macro_call: &ast::MacroCall) -> Option<MacroDef> {
         let sa = self.analyze(macro_call.syntax());
         let macro_call = self.find_file(macro_call.syntax().clone()).with_value(macro_call);
         sa.resolve_macro_call(self.db, macro_call)
     }
 
-    pub fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
+    fn resolve_path(&self, path: &ast::Path) -> Option<PathResolution> {
         self.analyze(path.syntax()).resolve_path(self.db, path)
     }
 
-    pub fn lower_path(&self, path: &ast::Path) -> Option<Path> {
+    fn resolve_variant(&self, record_lit: ast::RecordLit) -> Option<VariantId> {
+        self.analyze(record_lit.syntax()).resolve_variant(self.db, record_lit)
+    }
+
+    fn lower_path(&self, path: &ast::Path) -> Option<Path> {
         let src = self.find_file(path.syntax().clone());
         Path::from_src(path.clone(), &Hygiene::new(self.db.upcast(), src.file_id.into()))
     }
 
-    pub fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
+    fn resolve_bind_pat_to_const(&self, pat: &ast::BindPat) -> Option<ModuleDef> {
         self.analyze(pat.syntax()).resolve_bind_pat_to_const(self.db, pat)
     }
 
-    // FIXME: use this instead?
-    // pub fn resolve_name_ref(&self, name_ref: &ast::NameRef) -> Option<???>;
-
-    pub fn record_literal_missing_fields(&self, literal: &ast::RecordLit) -> Vec<(Field, Type)> {
+    fn record_literal_missing_fields(&self, literal: &ast::RecordLit) -> Vec<(Field, Type)> {
         self.analyze(literal.syntax())
             .record_literal_missing_fields(self.db, literal)
             .unwrap_or_default()
     }
 
-    pub fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
+    fn record_pattern_missing_fields(&self, pattern: &ast::RecordPat) -> Vec<(Field, Type)> {
         self.analyze(pattern.syntax())
             .record_pattern_missing_fields(self.db, pattern)
             .unwrap_or_default()
     }
 
-    pub fn to_def<T: ToDef>(&self, src: &T) -> Option<T::Def> {
-        let src = self.find_file(src.syntax().clone()).with_value(src).cloned();
-        T::to_def(self, src)
-    }
-
     fn with_ctx<F: FnOnce(&mut SourceToDefCtx) -> T, T>(&self, f: F) -> T {
         let mut cache = self.s2d_cache.borrow_mut();
         let mut ctx = SourceToDefCtx { db: self.db, cache: &mut *cache };
         f(&mut ctx)
     }
 
-    pub fn to_module_def(&self, file: FileId) -> Option<Module> {
+    fn to_module_def(&self, file: FileId) -> Option<Module> {
         self.with_ctx(|ctx| ctx.file_to_def(file)).map(Module::from)
     }
 
-    pub fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db, DB> {
+    fn scope(&self, node: &SyntaxNode) -> SemanticsScope<'db> {
         let node = self.find_file(node.clone());
         let resolver = self.analyze2(node.as_ref(), None).resolver;
         SemanticsScope { db: self.db, resolver }
     }
 
-    pub fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db, DB> {
+    fn scope_at_offset(&self, node: &SyntaxNode, offset: TextSize) -> SemanticsScope<'db> {
         let node = self.find_file(node.clone());
         let resolver = self.analyze2(node.as_ref(), Some(offset)).resolver;
         SemanticsScope { db: self.db, resolver }
     }
 
-    pub fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db, DB> {
-        let resolver = def.id.resolver(self.db);
+    fn scope_for_def(&self, def: Trait) -> SemanticsScope<'db> {
+        let resolver = def.id.resolver(self.db.upcast());
         SemanticsScope { db: self.db, resolver }
     }
 
@@ -319,12 +480,13 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
             ChildContainer::DefWithBodyId(def) => {
                 return SourceAnalyzer::new_for_body(self.db, def, src, offset)
             }
-            ChildContainer::TraitId(it) => it.resolver(self.db),
-            ChildContainer::ImplId(it) => it.resolver(self.db),
-            ChildContainer::ModuleId(it) => it.resolver(self.db),
-            ChildContainer::EnumId(it) => it.resolver(self.db),
-            ChildContainer::VariantId(it) => it.resolver(self.db),
-            ChildContainer::GenericDefId(it) => it.resolver(self.db),
+            ChildContainer::TraitId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::ImplId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::ModuleId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::EnumId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::VariantId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::TypeAliasId(it) => it.resolver(self.db.upcast()),
+            ChildContainer::GenericDefId(it) => it.resolver(self.db.upcast()),
         };
         SourceAnalyzer::new_for_resolver(resolver, src)
     }
@@ -336,7 +498,7 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         assert!(prev == None || prev == Some(file_id))
     }
 
-    pub fn assert_contains_node(&self, node: &SyntaxNode) {
+    fn assert_contains_node(&self, node: &SyntaxNode) {
         self.find_file(node.clone());
     }
 
@@ -370,14 +532,14 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
 pub trait ToDef: AstNode + Clone {
     type Def;
 
-    fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: InFile<Self>) -> Option<Self::Def>;
+    fn to_def(sema: &SemanticsImpl, src: InFile<Self>) -> Option<Self::Def>;
 }
 
 macro_rules! to_def_impls {
     ($(($def:path, $ast:path, $meth:ident)),* ,) => {$(
         impl ToDef for $ast {
             type Def = $def;
-            fn to_def<DB: HirDatabase>(sema: &Semantics<DB>, src: InFile<Self>) -> Option<Self::Def> {
+            fn to_def(sema: &SemanticsImpl, src: InFile<Self>) -> Option<Self::Def> {
                 sema.with_ctx(|ctx| ctx.$meth(src)).map(<$def>::from)
             }
         }
@@ -407,12 +569,13 @@ fn find_root(node: &SyntaxNode) -> SyntaxNode {
     node.ancestors().last().unwrap()
 }
 
-pub struct SemanticsScope<'a, DB> {
-    pub db: &'a DB,
+#[derive(Debug)]
+pub struct SemanticsScope<'a> {
+    pub db: &'a dyn HirDatabase,
     resolver: Resolver,
 }
 
-impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
+impl<'a> SemanticsScope<'a> {
     pub fn module(&self) -> Option<Module> {
         Some(Module { id: self.resolver.module()? })
     }
@@ -421,13 +584,13 @@ impl<'a, DB: HirDatabase> SemanticsScope<'a, DB> {
     // FIXME: rename to visible_traits to not repeat scope?
     pub fn traits_in_scope(&self) -> FxHashSet<TraitId> {
         let resolver = &self.resolver;
-        resolver.traits_in_scope(self.db)
+        resolver.traits_in_scope(self.db.upcast())
     }
 
     pub fn process_all_names(&self, f: &mut dyn FnMut(Name, ScopeDef)) {
         let resolver = &self.resolver;
 
-        resolver.process_all_names(self.db, &mut |name, def| {
+        resolver.process_all_names(self.db.upcast(), &mut |name, def| {
             let def = match def {
                 resolver::ScopeDef::PerNs(it) => {
                     let items = ScopeDef::all_items(it);
diff --git a/crates/ra_hir/src/semantics/source_to_def.rs b/crates/ra_hir/src/semantics/source_to_def.rs
index 8af64fdc1..42e5a1bdb 100644
--- a/crates/ra_hir/src/semantics/source_to_def.rs
+++ b/crates/ra_hir/src/semantics/source_to_def.rs
@@ -16,6 +16,7 @@ use ra_syntax::{
     match_ast, AstNode, SyntaxNode,
 };
 use rustc_hash::FxHashMap;
+use stdx::impl_from;
 
 use crate::{db::HirDatabase, InFile, MacroDefId};
 
@@ -194,6 +195,10 @@ impl SourceToDefCtx<'_, '_> {
                         let def = self.const_to_def(container.with_value(it))?;
                         DefWithBodyId::from(def).into()
                     },
+                    ast::TypeAliasDef(it) => {
+                        let def = self.type_alias_to_def(container.with_value(it))?;
+                        def.into()
+                    },
                     _ => continue,
                 }
             };
@@ -246,19 +251,21 @@ pub(crate) enum ChildContainer {
     ImplId(ImplId),
     EnumId(EnumId),
     VariantId(VariantId),
+    TypeAliasId(TypeAliasId),
     /// XXX: this might be the same def as, for example an `EnumId`. However,
     /// here the children generic parameters, and not, eg enum variants.
     GenericDefId(GenericDefId),
 }
-impl_froms! {
-    ChildContainer:
+impl_from! {
     DefWithBodyId,
     ModuleId,
     TraitId,
     ImplId,
     EnumId,
     VariantId,
+    TypeAliasId,
     GenericDefId
+    for ChildContainer
 }
 
 impl ChildContainer {
@@ -271,6 +278,7 @@ impl ChildContainer {
             ChildContainer::ImplId(it) => it.child_by_source(db),
             ChildContainer::EnumId(it) => it.child_by_source(db),
             ChildContainer::VariantId(it) => it.child_by_source(db),
+            ChildContainer::TypeAliasId(_) => DynMap::default(),
             ChildContainer::GenericDefId(it) => it.child_by_source(db),
         }
     }
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index 4b509f07c..ecb54f653 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -18,7 +18,7 @@ use hir_def::{
 };
 use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile};
 use hir_ty::{
-    expr::{record_literal_missing_fields, record_pattern_missing_fields},
+    diagnostics::{record_literal_missing_fields, record_pattern_missing_fields},
     InferenceResult, Substs, Ty,
 };
 use ra_syntax::{
@@ -115,7 +115,7 @@ impl SourceAnalyzer {
         Some(res)
     }
 
-    pub(crate) fn type_of(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<Type> {
+    pub(crate) fn type_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<Type> {
         let expr_id = self.expr_id(db, expr)?;
         let ty = self.infer.as_ref()?[expr_id].clone();
         Type::new_with_resolver(db, &self.resolver, ty)
@@ -127,6 +127,17 @@ impl SourceAnalyzer {
         Type::new_with_resolver(db, &self.resolver, ty)
     }
 
+    pub(crate) fn type_of_self(
+        &self,
+        db: &dyn HirDatabase,
+        param: &ast::SelfParam,
+    ) -> Option<Type> {
+        let src = InFile { file_id: self.file_id, value: param };
+        let pat_id = self.body_source_map.as_ref()?.node_self_param(src)?;
+        let ty = self.infer.as_ref()?[pat_id].clone();
+        Type::new_with_resolver(db, &self.resolver, ty)
+    }
+
     pub(crate) fn resolve_method_call(
         &self,
         db: &dyn HirDatabase,
@@ -216,13 +227,43 @@ impl SourceAnalyzer {
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
                 return Some(PathResolution::AssocItem(assoc.into()));
             }
+            if let Some(VariantId::EnumVariantId(variant)) =
+                self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
+            {
+                return Some(PathResolution::Def(ModuleDef::EnumVariant(variant.into())));
+            }
         }
+
         if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {
             let pat_id = self.pat_id(&path_pat.into())?;
             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
                 return Some(PathResolution::AssocItem(assoc.into()));
             }
+            if let Some(VariantId::EnumVariantId(variant)) =
+                self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
+            {
+                return Some(PathResolution::Def(ModuleDef::EnumVariant(variant.into())));
+            }
+        }
+
+        if let Some(rec_lit) = path.syntax().parent().and_then(ast::RecordLit::cast) {
+            let expr_id = self.expr_id(db, &rec_lit.into())?;
+            if let Some(VariantId::EnumVariantId(variant)) =
+                self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
+            {
+                return Some(PathResolution::Def(ModuleDef::EnumVariant(variant.into())));
+            }
+        }
+
+        if let Some(rec_pat) = path.syntax().parent().and_then(ast::RecordPat::cast) {
+            let pat_id = self.pat_id(&rec_pat.into())?;
+            if let Some(VariantId::EnumVariantId(variant)) =
+                self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
+            {
+                return Some(PathResolution::Def(ModuleDef::EnumVariant(variant.into())));
+            }
         }
+
         // This must be a normal source file rather than macro file.
         let hir_path =
             crate::Path::from_src(path.clone(), &Hygiene::new(db.upcast(), self.file_id))?;
@@ -307,10 +348,21 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
     ) -> Option<HirFileId> {
-        let macro_call_id = macro_call.as_call_id(db.upcast(), |path| {
+        let krate = self.resolver.krate()?;
+        let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
             self.resolver.resolve_path_as_macro(db.upcast(), &path)
         })?;
-        Some(macro_call_id.as_file())
+        Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
+    }
+
+    pub(crate) fn resolve_variant(
+        &self,
+        db: &dyn HirDatabase,
+        record_lit: ast::RecordLit,
+    ) -> Option<VariantId> {
+        let infer = self.infer.as_ref()?;
+        let expr_id = self.expr_id(db, &record_lit.into())?;
+        infer.variant_resolution_for_expr(expr_id)
     }
 }
 
diff --git a/crates/ra_hir_def/Cargo.toml b/crates/ra_hir_def/Cargo.toml
index b85358308..1ec619b42 100644
--- a/crates/ra_hir_def/Cargo.toml
+++ b/crates/ra_hir_def/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_hir_def"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -14,6 +15,10 @@ rustc-hash = "1.1.0"
 either = "1.5.3"
 anymap = "0.12.1"
 drop_bomb = "0.1.4"
+fst = { version = "0.4", default-features = false }
+itertools = "0.9.0"
+indexmap = "1.4.0"
+smallvec = "1.4.0"
 
 stdx = { path = "../stdx" }
 
@@ -29,3 +34,4 @@ tt = { path = "../ra_tt", package = "ra_tt" }
 
 [dev-dependencies]
 insta = "0.16.0"
+expect = { path = "../expect" }
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index 2bc34d449..4994a2125 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -8,12 +8,12 @@ use hir_expand::{
     InFile,
 };
 use ra_arena::{map::ArenaMap, Arena};
-use ra_prof::profile;
 use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner, VisibilityOwner};
 
 use crate::{
     body::{CfgExpander, LowerCtx},
     db::DefDatabase,
+    item_tree::{Field, Fields, ItemTree},
     src::HasChildSource,
     src::HasSource,
     trace::Trace,
@@ -22,6 +22,7 @@ use crate::{
     EnumId, HasModule, LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StructId, UnionId,
     VariantId,
 };
+use ra_cfg::CfgOptions;
 
 /// Note that we use `StructData` for unions as well!
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -59,39 +60,48 @@ pub struct FieldData {
 
 impl StructData {
     pub(crate) fn struct_data_query(db: &dyn DefDatabase, id: StructId) -> Arc<StructData> {
-        let src = id.lookup(db).source(db);
+        let loc = id.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
 
-        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
-        let variant_data =
-            VariantData::new(db, src.map(|s| s.kind()), id.lookup(db).container.module(db));
-        let variant_data = Arc::new(variant_data);
-        Arc::new(StructData { name, variant_data })
+        let strukt = &item_tree[loc.id.value];
+        let variant_data = lower_fields(&item_tree, &cfg_options, &strukt.fields);
+
+        Arc::new(StructData { name: strukt.name.clone(), variant_data: Arc::new(variant_data) })
     }
     pub(crate) fn union_data_query(db: &dyn DefDatabase, id: UnionId) -> Arc<StructData> {
-        let src = id.lookup(db).source(db);
-        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
-        let variant_data = VariantData::new(
-            db,
-            src.map(|s| {
-                s.record_field_def_list()
-                    .map(ast::StructKind::Record)
-                    .unwrap_or(ast::StructKind::Unit)
-            }),
-            id.lookup(db).container.module(db),
-        );
-        let variant_data = Arc::new(variant_data);
-        Arc::new(StructData { name, variant_data })
+        let loc = id.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+
+        let union = &item_tree[loc.id.value];
+        let variant_data = lower_fields(&item_tree, &cfg_options, &union.fields);
+
+        Arc::new(StructData { name: union.name.clone(), variant_data: Arc::new(variant_data) })
     }
 }
 
 impl EnumData {
     pub(crate) fn enum_data_query(db: &dyn DefDatabase, e: EnumId) -> Arc<EnumData> {
-        let _p = profile("enum_data_query");
-        let src = e.lookup(db).source(db);
-        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
-        let mut trace = Trace::new_for_arena();
-        lower_enum(db, &mut trace, &src, e.lookup(db).container.module(db));
-        Arc::new(EnumData { name, variants: trace.into_arena() })
+        let loc = e.lookup(db);
+        let item_tree = db.item_tree(loc.id.file_id);
+        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+
+        let enum_ = &item_tree[loc.id.value];
+        let mut variants = Arena::new();
+        for var_id in enum_.variants.clone() {
+            if item_tree.attrs(var_id.into()).is_cfg_enabled(&cfg_options) {
+                let var = &item_tree[var_id];
+                let var_data = lower_fields(&item_tree, &cfg_options, &var.fields);
+
+                variants.alloc(EnumVariantData {
+                    name: var.name.clone(),
+                    variant_data: Arc::new(var_data),
+                });
+            }
+        }
+
+        Arc::new(EnumData { name: enum_.name.clone(), variants })
     }
 
     pub fn variant(&self, name: &Name) -> Option<LocalEnumVariantId> {
@@ -251,3 +261,35 @@ fn lower_struct(
         ast::StructKind::Unit => StructKind::Unit,
     }
 }
+
+fn lower_fields(item_tree: &ItemTree, cfg_options: &CfgOptions, fields: &Fields) -> VariantData {
+    match fields {
+        Fields::Record(flds) => {
+            let mut arena = Arena::new();
+            for field_id in flds.clone() {
+                if item_tree.attrs(field_id.into()).is_cfg_enabled(cfg_options) {
+                    arena.alloc(lower_field(item_tree, &item_tree[field_id]));
+                }
+            }
+            VariantData::Record(arena)
+        }
+        Fields::Tuple(flds) => {
+            let mut arena = Arena::new();
+            for field_id in flds.clone() {
+                if item_tree.attrs(field_id.into()).is_cfg_enabled(cfg_options) {
+                    arena.alloc(lower_field(item_tree, &item_tree[field_id]));
+                }
+            }
+            VariantData::Tuple(arena)
+        }
+        Fields::Unit => VariantData::Unit,
+    }
+}
+
+fn lower_field(item_tree: &ItemTree, field: &Field) -> FieldData {
+    FieldData {
+        name: field.name.clone(),
+        type_ref: field.type_ref.clone(),
+        visibility: item_tree[field.visibility].clone(),
+    }
+}
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 8b6c0bede..e228e2145 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -13,7 +13,11 @@ use ra_syntax::{
 use tt::Subtree;
 
 use crate::{
-    db::DefDatabase, nameres::ModuleSource, path::ModPath, src::HasChildSource, src::HasSource,
+    db::DefDatabase,
+    item_tree::{ItemTreeId, ItemTreeNode},
+    nameres::ModuleSource,
+    path::ModPath,
+    src::HasChildSource,
     AdtId, AttrDefId, Lookup,
 };
 
@@ -34,6 +38,8 @@ impl ops::Deref for Attrs {
 }
 
 impl Attrs {
+    pub const EMPTY: Attrs = Attrs { entries: None };
+
     pub(crate) fn attrs_query(db: &dyn DefDatabase, def: AttrDefId) -> Attrs {
         match def {
             AttrDefId::ModuleId(module) => {
@@ -65,19 +71,19 @@ impl Attrs {
                 Attrs::from_attrs_owner(db, src.map(|it| it as &dyn AttrsOwner))
             }
             AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => attrs_from_loc(it.lookup(db), db),
-                AdtId::EnumId(it) => attrs_from_loc(it.lookup(db), db),
-                AdtId::UnionId(it) => attrs_from_loc(it.lookup(db), db),
+                AdtId::StructId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+                AdtId::EnumId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+                AdtId::UnionId(it) => attrs_from_item_tree(it.lookup(db).id, db),
             },
-            AttrDefId::TraitId(it) => attrs_from_loc(it.lookup(db), db),
+            AttrDefId::TraitId(it) => attrs_from_item_tree(it.lookup(db).id, db),
             AttrDefId::MacroDefId(it) => {
                 it.ast_id.map_or_else(Default::default, |ast_id| attrs_from_ast(ast_id, db))
             }
-            AttrDefId::ImplId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::ConstId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::StaticId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::FunctionId(it) => attrs_from_loc(it.lookup(db), db),
-            AttrDefId::TypeAliasId(it) => attrs_from_loc(it.lookup(db), db),
+            AttrDefId::ImplId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+            AttrDefId::ConstId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+            AttrDefId::StaticId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+            AttrDefId::FunctionId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+            AttrDefId::TypeAliasId(it) => attrs_from_item_tree(it.lookup(db).id, db),
         }
     }
 
@@ -87,16 +93,34 @@ impl Attrs {
     }
 
     pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
+        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).doc_comment_text().map(
+            |docs_text| Attr {
+                input: Some(AttrInput::Literal(SmolStr::new(docs_text))),
+                path: ModPath::from(hir_expand::name!(doc)),
+            },
+        );
         let mut attrs = owner.attrs().peekable();
         let entries = if attrs.peek().is_none() {
             // Avoid heap allocation
             None
         } else {
-            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).chain(docs).collect())
         };
         Attrs { entries }
     }
 
+    pub fn merge(&self, other: Attrs) -> Attrs {
+        match (&self.entries, &other.entries) {
+            (None, None) => Attrs { entries: None },
+            (Some(entries), None) | (None, Some(entries)) => {
+                Attrs { entries: Some(entries.clone()) }
+            }
+            (Some(a), Some(b)) => {
+                Attrs { entries: Some(a.iter().chain(b.iter()).cloned().collect()) }
+            }
+        }
+    }
+
     pub fn by_key(&self, key: &'static str) -> AttrQuery<'_> {
         AttrQuery { attrs: self, key }
     }
@@ -181,11 +205,8 @@ where
     Attrs::from_attrs_owner(db, src.as_ref().map(|it| it as &dyn AttrsOwner))
 }
 
-fn attrs_from_loc<T>(node: T, db: &dyn DefDatabase) -> Attrs
-where
-    T: HasSource,
-    T::Value: ast::AttrsOwner,
-{
-    let src = node.source(db);
-    Attrs::from_attrs_owner(db, src.as_ref().map(|it| it as &dyn AttrsOwner))
+fn attrs_from_item_tree<N: ItemTreeNode>(id: ItemTreeId<N>, db: &dyn DefDatabase) -> Attrs {
+    let tree = db.item_tree(id.file_id);
+    let mod_item = N::id_to_mod_item(id.value);
+    tree.attrs(mod_item.into()).clone()
 }
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 273036cee..2fe04db2b 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -14,6 +14,7 @@ use ra_db::CrateId;
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, AstPtr};
 use rustc_hash::FxHashMap;
+use test_utils::mark;
 
 pub(crate) use lower::LowerCtx;
 
@@ -42,9 +43,15 @@ pub(crate) struct Expander {
     current_file_id: HirFileId,
     ast_id_map: Arc<AstIdMap>,
     module: ModuleId,
-    recursive_limit: usize,
+    recursion_limit: usize,
 }
 
+#[cfg(test)]
+const EXPANSION_RECURSION_LIMIT: usize = 32;
+
+#[cfg(not(test))]
+const EXPANSION_RECURSION_LIMIT: usize = 128;
+
 impl CfgExpander {
     pub(crate) fn new(
         db: &dyn DefDatabase,
@@ -81,7 +88,7 @@ impl Expander {
             current_file_id,
             ast_id_map,
             module,
-            recursive_limit: 0,
+            recursion_limit: 0,
         }
     }
 
@@ -91,13 +98,15 @@ impl Expander {
         local_scope: Option<&ItemScope>,
         macro_call: ast::MacroCall,
     ) -> Option<(Mark, T)> {
-        if self.recursive_limit > 1024 {
+        self.recursion_limit += 1;
+        if self.recursion_limit > EXPANSION_RECURSION_LIMIT {
+            mark::hit!(your_stack_belongs_to_me);
             return None;
         }
 
         let macro_call = InFile::new(self.current_file_id, &macro_call);
 
-        if let Some(call_id) = macro_call.as_call_id(db, |path| {
+        if let Some(call_id) = macro_call.as_call_id(db, self.crate_def_map.krate, |path| {
             if let Some(local_scope) = local_scope {
                 if let Some(def) = path.as_ident().and_then(|n| local_scope.get_legacy_macro(n)) {
                     return Some(def);
@@ -118,8 +127,6 @@ impl Expander {
                     self.cfg_expander.hygiene = Hygiene::new(db.upcast(), file_id);
                     self.current_file_id = file_id;
                     self.ast_id_map = db.ast_id_map(file_id);
-                    self.recursive_limit += 1;
-
                     return Some((mark, expr));
                 }
             }
@@ -134,7 +141,7 @@ impl Expander {
         self.cfg_expander.hygiene = Hygiene::new(db.upcast(), mark.file_id);
         self.current_file_id = mark.file_id;
         self.ast_id_map = mem::take(&mut mark.ast_id_map);
-        self.recursive_limit -= 1;
+        self.recursion_limit -= 1;
         mark.bomb.defuse();
     }
 
@@ -302,7 +309,53 @@ impl BodySourceMap {
         self.pat_map.get(&src).cloned()
     }
 
+    pub fn node_self_param(&self, node: InFile<&ast::SelfParam>) -> Option<PatId> {
+        let src = node.map(|it| Either::Right(AstPtr::new(it)));
+        self.pat_map.get(&src).cloned()
+    }
+
     pub fn field_syntax(&self, expr: ExprId, field: usize) -> InFile<AstPtr<ast::RecordField>> {
         self.field_map[&(expr, field)].clone()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use ra_db::{fixture::WithFixture, SourceDatabase};
+    use test_utils::mark;
+
+    use crate::ModuleDefId;
+
+    use super::*;
+
+    fn lower(ra_fixture: &str) -> Arc<Body> {
+        let (db, file_id) = crate::test_db::TestDB::with_single_file(ra_fixture);
+
+        let krate = db.crate_graph().iter().next().unwrap();
+        let def_map = db.crate_def_map(krate);
+        let module = def_map.modules_for_file(file_id).next().unwrap();
+        let module = &def_map[module];
+        let fn_def = match module.scope.declarations().next().unwrap() {
+            ModuleDefId::FunctionId(it) => it,
+            _ => panic!(),
+        };
+
+        db.body(fn_def.into())
+    }
+
+    #[test]
+    fn your_stack_belongs_to_me() {
+        mark::check!(your_stack_belongs_to_me);
+        lower(
+            "
+macro_rules! n_nuple {
+    ($e:tt) => ();
+    ($($rest:tt)*) => {{
+        (n_nuple!($($rest)*)None,)
+    }};
+}
+fn main() { n_nuple!(1,2,3); }
+",
+        );
+    }
+}
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index f159f80af..c6bc85e2f 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -27,6 +27,7 @@ use crate::{
         LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
     },
     item_scope::BuiltinShadowMode,
+    item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
     AdtId, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern, ModuleDefId,
@@ -35,6 +36,8 @@ use crate::{
 
 use super::{ExprSource, PatSource};
 use ast::AstChildren;
+use rustc_hash::FxHashMap;
+use std::{any::type_name, sync::Arc};
 
 pub(crate) struct LowerCtx {
     hygiene: Hygiene,
@@ -60,10 +63,10 @@ pub(super) fn lower(
     params: Option<ast::ParamList>,
     body: Option<ast::Expr>,
 ) -> (Body, BodySourceMap) {
+    let item_tree = db.item_tree(expander.current_file_id);
     ExprCollector {
         db,
         def,
-        expander,
         source_map: BodySourceMap::default(),
         body: Body {
             exprs: Arena::default(),
@@ -72,6 +75,12 @@ pub(super) fn lower(
             body_expr: dummy_expr_id(),
             item_scope: Default::default(),
         },
+        item_trees: {
+            let mut map = FxHashMap::default();
+            map.insert(expander.current_file_id, item_tree);
+            map
+        },
+        expander,
     }
     .collect(params, body)
 }
@@ -82,6 +91,8 @@ struct ExprCollector<'a> {
     expander: Expander,
     body: Body,
     source_map: BodySourceMap,
+
+    item_trees: FxHashMap<HirFileId, Arc<ItemTree>>,
 }
 
 impl ExprCollector<'_> {
@@ -165,6 +176,7 @@ impl ExprCollector<'_> {
         if !self.expander.is_cfg_enabled(&expr) {
             return self.missing_expr();
         }
+
         match expr {
             ast::Expr::IfExpr(e) => {
                 let then_branch = self.collect_block_opt(e.then_branch());
@@ -207,8 +219,12 @@ impl ExprCollector<'_> {
                     let body = self.collect_block_opt(e.block_expr());
                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
                 }
+                ast::Effect::Unsafe(_) => {
+                    let body = self.collect_block_opt(e.block_expr());
+                    self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
+                }
                 // FIXME: we need to record these effects somewhere...
-                ast::Effect::Async(_) | ast::Effect::Label(_) | ast::Effect::Unsafe(_) => {
+                ast::Effect::Async(_) | ast::Effect::Label(_) => {
                     self.collect_block_opt(e.block_expr())
                 }
             },
@@ -434,7 +450,6 @@ impl ExprCollector<'_> {
                     Mutability::from_mutable(e.mut_token().is_some())
                 };
                 let rawness = Rawness::from_raw(raw_tok);
-
                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
             }
             ast::Expr::PrefixExpr(e) => {
@@ -533,6 +548,9 @@ impl ExprCollector<'_> {
                             self.source_map
                                 .expansions
                                 .insert(macro_call, self.expander.current_file_id);
+
+                            let item_tree = self.db.item_tree(self.expander.current_file_id);
+                            self.item_trees.insert(self.expander.current_file_id, item_tree);
                             let id = self.collect_expr(expansion);
                             self.expander.exit(self.db, mark);
                             id
@@ -547,6 +565,32 @@ impl ExprCollector<'_> {
         }
     }
 
+    fn find_inner_item<N: ItemTreeNode>(&self, ast: &N::Source) -> Option<ItemTreeId<N>> {
+        let id = self.expander.ast_id(ast);
+        let tree = &self.item_trees[&id.file_id];
+
+        // FIXME: This probably breaks with `use` items, since they produce multiple item tree nodes
+
+        // Root file (non-macro).
+        let item_tree_id = tree
+            .all_inner_items()
+            .chain(tree.top_level_items().iter().copied())
+            .filter_map(|mod_item| mod_item.downcast::<N>())
+            .find(|tree_id| tree[*tree_id].ast_id().upcast() == id.value.upcast())
+            .or_else(|| {
+                log::debug!(
+                    "couldn't find inner {} item for {:?} (AST: `{}` - {:?})",
+                    type_name::<N>(),
+                    id,
+                    ast.syntax(),
+                    ast.syntax(),
+                );
+                None
+            })?;
+
+        Some(ItemTreeId::new(id.file_id, item_tree_id))
+    }
+
     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
         if let Some(expr) = expr {
             self.collect_expr(expr)
@@ -578,56 +622,65 @@ impl ExprCollector<'_> {
 
     fn collect_block_items(&mut self, block: &ast::BlockExpr) {
         let container = ContainerId::DefWithBodyId(self.def);
-        for item in block.items() {
-            let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
-                ast::ModuleItem::FnDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (
-                        FunctionLoc { container: container.into(), ast_id }.intern(self.db).into(),
-                        def.name(),
-                    )
-                }
-                ast::ModuleItem::TypeAliasDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (
-                        TypeAliasLoc { container: container.into(), ast_id }.intern(self.db).into(),
-                        def.name(),
-                    )
-                }
-                ast::ModuleItem::ConstDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (
-                        ConstLoc { container: container.into(), ast_id }.intern(self.db).into(),
-                        def.name(),
-                    )
-                }
-                ast::ModuleItem::StaticDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (StaticLoc { container, ast_id }.intern(self.db).into(), def.name())
-                }
-                ast::ModuleItem::StructDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (StructLoc { container, ast_id }.intern(self.db).into(), def.name())
-                }
-                ast::ModuleItem::EnumDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (EnumLoc { container, ast_id }.intern(self.db).into(), def.name())
-                }
-                ast::ModuleItem::UnionDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (UnionLoc { container, ast_id }.intern(self.db).into(), def.name())
-                }
-                ast::ModuleItem::TraitDef(def) => {
-                    let ast_id = self.expander.ast_id(&def);
-                    (TraitLoc { container, ast_id }.intern(self.db).into(), def.name())
-                }
-                ast::ModuleItem::ExternBlock(_) => continue, // FIXME: collect from extern blocks
-                ast::ModuleItem::ImplDef(_)
-                | ast::ModuleItem::UseItem(_)
-                | ast::ModuleItem::ExternCrateItem(_)
-                | ast::ModuleItem::Module(_)
-                | ast::ModuleItem::MacroCall(_) => continue,
-            };
+
+        let items = block
+            .items()
+            .filter_map(|item| {
+                let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
+                    ast::ModuleItem::FnDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (
+                            FunctionLoc { container: container.into(), id }.intern(self.db).into(),
+                            def.name(),
+                        )
+                    }
+                    ast::ModuleItem::TypeAliasDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (
+                            TypeAliasLoc { container: container.into(), id }.intern(self.db).into(),
+                            def.name(),
+                        )
+                    }
+                    ast::ModuleItem::ConstDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (
+                            ConstLoc { container: container.into(), id }.intern(self.db).into(),
+                            def.name(),
+                        )
+                    }
+                    ast::ModuleItem::StaticDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (StaticLoc { container, id }.intern(self.db).into(), def.name())
+                    }
+                    ast::ModuleItem::StructDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (StructLoc { container, id }.intern(self.db).into(), def.name())
+                    }
+                    ast::ModuleItem::EnumDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (EnumLoc { container, id }.intern(self.db).into(), def.name())
+                    }
+                    ast::ModuleItem::UnionDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (UnionLoc { container, id }.intern(self.db).into(), def.name())
+                    }
+                    ast::ModuleItem::TraitDef(def) => {
+                        let id = self.find_inner_item(&def)?;
+                        (TraitLoc { container, id }.intern(self.db).into(), def.name())
+                    }
+                    ast::ModuleItem::ExternBlock(_) => return None, // FIXME: collect from extern blocks
+                    ast::ModuleItem::ImplDef(_)
+                    | ast::ModuleItem::UseItem(_)
+                    | ast::ModuleItem::ExternCrateItem(_)
+                    | ast::ModuleItem::Module(_)
+                    | ast::ModuleItem::MacroCall(_) => return None,
+                };
+
+                Some((def, name))
+            })
+            .collect::<Vec<_>>();
+
+        for (def, name) in items {
             self.body.item_scope.define_def(def);
             if let Some(name) = name {
                 let vis = crate::visibility::Visibility::Public; // FIXME determine correctly
diff --git a/crates/ra_hir_def/src/body/scope.rs b/crates/ra_hir_def/src/body/scope.rs
index e48ff38f9..99e876683 100644
--- a/crates/ra_hir_def/src/body/scope.rs
+++ b/crates/ra_hir_def/src/body/scope.rs
@@ -87,15 +87,13 @@ impl ExprScopes {
     }
 
     fn add_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) {
-        match &body[pat] {
-            Pat::Bind { name, .. } => {
-                // bind can have a sub pattern, but it's actually not allowed
-                // to bind to things in there
-                let entry = ScopeEntry { name: name.clone(), pat };
-                self.scopes[scope].entries.push(entry)
-            }
-            p => p.walk_child_pats(|pat| self.add_bindings(body, scope, pat)),
+        let pattern = &body[pat];
+        if let Pat::Bind { name, .. } = pattern {
+            let entry = ScopeEntry { name: name.clone(), pat };
+            self.scopes[scope].entries.push(entry);
         }
+
+        pattern.walk_child_pats(|pat| self.add_bindings(body, scope, pat));
     }
 
     fn add_params_bindings(&mut self, body: &Body, scope: ScopeId, params: &[PatId]) {
@@ -190,21 +188,23 @@ mod tests {
         }
     }
 
-    fn do_check(code: &str, expected: &[&str]) {
-        let (off, code) = extract_offset(code);
+    fn do_check(ra_fixture: &str, expected: &[&str]) {
+        let (offset, code) = extract_offset(ra_fixture);
         let code = {
             let mut buf = String::new();
-            let off: usize = off.into();
+            let off: usize = offset.into();
             buf.push_str(&code[..off]);
-            buf.push_str("marker");
+            buf.push_str("<|>marker");
             buf.push_str(&code[off..]);
             buf
         };
 
-        let (db, file_id) = TestDB::with_single_file(&code);
+        let (db, position) = TestDB::with_position(&code);
+        let file_id = position.file_id;
+        let offset = position.offset;
 
         let file_syntax = db.parse(file_id).syntax_node();
-        let marker: ast::PathExpr = find_node_at_offset(&file_syntax, off).unwrap();
+        let marker: ast::PathExpr = find_node_at_offset(&file_syntax, offset).unwrap();
         let function = find_function(&db, file_id);
 
         let scopes = db.expr_scopes(function.into());
@@ -300,15 +300,65 @@ mod tests {
         );
     }
 
-    fn do_check_local_name(code: &str, expected_offset: u32) {
-        let (off, code) = extract_offset(code);
+    #[test]
+    fn test_bindings_after_at() {
+        do_check(
+            r"
+fn foo() {
+    match Some(()) {
+        opt @ Some(unit) => {
+            <|>
+        }
+        _ => {}
+    }
+}
+",
+            &["opt", "unit"],
+        );
+    }
+
+    #[test]
+    fn macro_inner_item() {
+        do_check(
+            r"
+            macro_rules! mac {
+                () => {{
+                    fn inner() {}
+                    inner();
+                }};
+            }
+
+            fn foo() {
+                mac!();
+                <|>
+            }
+        ",
+            &[],
+        );
+    }
+
+    #[test]
+    fn broken_inner_item() {
+        do_check(
+            r"
+            fn foo() {
+                trait {}
+                <|>
+            }
+        ",
+            &[],
+        );
+    }
 
-        let (db, file_id) = TestDB::with_single_file(&code);
+    fn do_check_local_name(ra_fixture: &str, expected_offset: u32) {
+        let (db, position) = TestDB::with_position(ra_fixture);
+        let file_id = position.file_id;
+        let offset = position.offset;
 
         let file = db.parse(file_id).ok().unwrap();
         let expected_name = find_node_at_offset::<ast::Name>(file.syntax(), expected_offset.into())
             .expect("failed to find a name at the target offset");
-        let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
+        let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), offset).unwrap();
 
         let function = find_function(&db, file_id);
 
@@ -336,15 +386,16 @@ mod tests {
     fn test_resolve_local_name() {
         do_check_local_name(
             r#"
-            fn foo(x: i32, y: u32) {
-                {
-                    let z = x * 2;
-                }
-                {
-                    let t = x<|> * 3;
-                }
-            }"#,
-            21,
+fn foo(x: i32, y: u32) {
+    {
+        let z = x * 2;
+    }
+    {
+        let t = x<|> * 3;
+    }
+}
+"#,
+            7,
         );
     }
 
@@ -352,10 +403,11 @@ mod tests {
     fn test_resolve_local_name_declaration() {
         do_check_local_name(
             r#"
-            fn foo(x: String) {
-                let x : &str = &x<|>;
-            }"#,
-            21,
+fn foo(x: String) {
+    let x : &str = &x<|>;
+}
+"#,
+            7,
         );
     }
 
@@ -363,12 +415,12 @@ mod tests {
     fn test_resolve_local_name_shadow() {
         do_check_local_name(
             r"
-            fn foo(x: String) {
-                let x : &str = &x;
-                x<|>
-            }
-            ",
-            53,
+fn foo(x: String) {
+    let x : &str = &x;
+    x<|>
+}
+",
+            28,
         );
     }
 
@@ -376,13 +428,13 @@ mod tests {
     fn ref_patterns_contribute_bindings() {
         do_check_local_name(
             r"
-            fn foo() {
-                if let Some(&from) = bar() {
-                    from<|>;
-                }
-            }
-            ",
-            53,
+fn foo() {
+    if let Some(&from) = bar() {
+        from<|>;
+    }
+}
+",
+            28,
         );
     }
 
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index e2130d931..88a8ef9bf 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -2,27 +2,19 @@
 
 use std::sync::Arc;
 
-use hir_expand::{
-    hygiene::Hygiene,
-    name::{name, AsName, Name},
-    AstId, InFile,
-};
+use hir_expand::{name::Name, InFile};
 use ra_prof::profile;
-use ra_syntax::ast::{
-    self, AssocItem, AstNode, ModuleItemOwner, NameOwner, TypeAscriptionOwner, TypeBoundsOwner,
-    VisibilityOwner,
-};
+use ra_syntax::ast;
 
 use crate::{
     attr::Attrs,
-    body::LowerCtx,
+    body::Expander,
     db::DefDatabase,
-    path::{path, AssociatedTypeBinding, GenericArgs, Path},
-    src::HasSource,
-    type_ref::{Mutability, TypeBound, TypeRef},
+    item_tree::{AssocItem, ItemTreeId, ModItem},
+    type_ref::{TypeBound, TypeRef},
     visibility::RawVisibility,
-    AssocContainerId, AssocItemId, ConstId, ConstLoc, Expander, FunctionId, FunctionLoc, HasModule,
-    ImplId, Intern, Lookup, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
+    AssocContainerId, AssocItemId, ConstId, ConstLoc, FunctionId, FunctionLoc, HasModule, ImplId,
+    Intern, Lookup, ModuleId, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -34,85 +26,36 @@ pub struct FunctionData {
     /// True if the first param is `self`. This is relevant to decide whether this
     /// can be called as a method.
     pub has_self_param: bool,
+    pub is_unsafe: bool,
+    pub is_varargs: bool,
     pub visibility: RawVisibility,
 }
 
 impl FunctionData {
-    pub(crate) fn fn_data_query(db: &impl DefDatabase, func: FunctionId) -> Arc<FunctionData> {
+    pub(crate) fn fn_data_query(db: &dyn DefDatabase, func: FunctionId) -> Arc<FunctionData> {
         let loc = func.lookup(db);
-        let src = loc.source(db);
-        let ctx = LowerCtx::new(db, src.file_id);
-        let name = src.value.name().map(|n| n.as_name()).unwrap_or_else(Name::missing);
-        let mut params = Vec::new();
-        let mut has_self_param = false;
-        if let Some(param_list) = src.value.param_list() {
-            if let Some(self_param) = param_list.self_param() {
-                let self_type = if let Some(type_ref) = self_param.ascribed_type() {
-                    TypeRef::from_ast(&ctx, type_ref)
-                } else {
-                    let self_type = TypeRef::Path(name![Self].into());
-                    match self_param.kind() {
-                        ast::SelfParamKind::Owned => self_type,
-                        ast::SelfParamKind::Ref => {
-                            TypeRef::Reference(Box::new(self_type), Mutability::Shared)
-                        }
-                        ast::SelfParamKind::MutRef => {
-                            TypeRef::Reference(Box::new(self_type), Mutability::Mut)
-                        }
-                    }
-                };
-                params.push(self_type);
-                has_self_param = true;
-            }
-            for param in param_list.params() {
-                let type_ref = TypeRef::from_ast_opt(&ctx, param.ascribed_type());
-                params.push(type_ref);
-            }
-        }
-        let attrs = Attrs::new(&src.value, &Hygiene::new(db.upcast(), src.file_id));
-
-        let ret_type = if let Some(type_ref) = src.value.ret_type().and_then(|rt| rt.type_ref()) {
-            TypeRef::from_ast(&ctx, type_ref)
-        } else {
-            TypeRef::unit()
-        };
-
-        let ret_type = if src.value.async_token().is_some() {
-            let future_impl = desugar_future_path(ret_type);
-            let ty_bound = TypeBound::Path(future_impl);
-            TypeRef::ImplTrait(vec![ty_bound])
-        } else {
-            ret_type
-        };
-
-        let vis_default = RawVisibility::default_for_container(loc.container);
-        let visibility =
-            RawVisibility::from_ast_with_default(db, vis_default, src.map(|s| s.visibility()));
-
-        let sig = FunctionData { name, params, ret_type, has_self_param, visibility, attrs };
-        Arc::new(sig)
+        let item_tree = db.item_tree(loc.id.file_id);
+        let func = &item_tree[loc.id.value];
+
+        Arc::new(FunctionData {
+            name: func.name.clone(),
+            params: func.params.to_vec(),
+            ret_type: func.ret_type.clone(),
+            attrs: item_tree.attrs(ModItem::from(loc.id.value).into()).clone(),
+            has_self_param: func.has_self_param,
+            is_unsafe: func.is_unsafe,
+            is_varargs: func.is_varargs,
+            visibility: item_tree[func.visibility].clone(),
+        })
     }
 }
 
-fn desugar_future_path(orig: TypeRef) -> Path {
-    let path = path![std::future::Future];
-    let mut generic_args: Vec<_> = std::iter::repeat(None).take(path.segments.len() - 1).collect();
-    let mut last = GenericArgs::empty();
-    last.bindings.push(AssociatedTypeBinding {
-        name: name![Output],
-        type_ref: Some(orig),
-        bounds: Vec::new(),
-    });
-    generic_args.push(Some(Arc::new(last)));
-
-    Path::from_known_path(path, generic_args)
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct TypeAliasData {
     pub name: Name,
     pub type_ref: Option<TypeRef>,
     pub visibility: RawVisibility,
+    /// Bounds restricting the type alias itself (eg. `type Ty: Bound;` in a trait or impl).
     pub bounds: Vec<TypeBound>,
 }
 
@@ -122,22 +65,15 @@ impl TypeAliasData {
         typ: TypeAliasId,
     ) -> Arc<TypeAliasData> {
         let loc = typ.lookup(db);
-        let node = loc.source(db);
-        let name = node.value.name().map_or_else(Name::missing, |n| n.as_name());
-        let lower_ctx = LowerCtx::new(db, node.file_id);
-        let type_ref = node.value.type_ref().map(|it| TypeRef::from_ast(&lower_ctx, it));
-        let vis_default = RawVisibility::default_for_container(loc.container);
-        let visibility = RawVisibility::from_ast_with_default(
-            db,
-            vis_default,
-            node.as_ref().map(|n| n.visibility()),
-        );
-        let bounds = if let Some(bound_list) = node.value.type_bound_list() {
-            bound_list.bounds().map(|it| TypeBound::from_ast(&lower_ctx, it)).collect()
-        } else {
-            Vec::new()
-        };
-        Arc::new(TypeAliasData { name, type_ref, visibility, bounds })
+        let item_tree = db.item_tree(loc.id.file_id);
+        let typ = &item_tree[loc.id.value];
+
+        Arc::new(TypeAliasData {
+            name: typ.name.clone(),
+            type_ref: typ.type_ref.clone(),
+            visibility: item_tree[typ.visibility].clone(),
+            bounds: typ.bounds.to_vec(),
+        })
     }
 }
 
@@ -151,30 +87,24 @@ pub struct TraitData {
 impl TraitData {
     pub(crate) fn trait_data_query(db: &dyn DefDatabase, tr: TraitId) -> Arc<TraitData> {
         let tr_loc = tr.lookup(db);
-        let src = tr_loc.source(db);
-        let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
-        let auto = src.value.auto_token().is_some();
+        let item_tree = db.item_tree(tr_loc.id.file_id);
+        let tr_def = &item_tree[tr_loc.id.value];
+        let name = tr_def.name.clone();
+        let auto = tr_def.auto;
         let module_id = tr_loc.container.module(db);
-
         let container = AssocContainerId::TraitId(tr);
-        let mut items = Vec::new();
-
-        if let Some(item_list) = src.value.item_list() {
-            let mut expander = Expander::new(db, tr_loc.ast_id.file_id, module_id);
-            items.extend(collect_items(
-                db,
-                &mut expander,
-                item_list.assoc_items(),
-                src.file_id,
-                container,
-            ));
-            items.extend(collect_items_in_macros(
-                db,
-                &mut expander,
-                &src.with_value(item_list),
-                container,
-            ));
-        }
+        let mut expander = Expander::new(db, tr_loc.id.file_id, module_id);
+
+        let items = collect_items(
+            db,
+            module_id,
+            &mut expander,
+            tr_def.items.iter().copied(),
+            tr_loc.id.file_id,
+            container,
+            100,
+        );
+
         Arc::new(TraitData { name, items, auto })
     }
 
@@ -205,33 +135,28 @@ impl ImplData {
     pub(crate) fn impl_data_query(db: &dyn DefDatabase, id: ImplId) -> Arc<ImplData> {
         let _p = profile("impl_data_query");
         let impl_loc = id.lookup(db);
-        let src = impl_loc.source(db);
-        let lower_ctx = LowerCtx::new(db, src.file_id);
 
-        let target_trait = src.value.target_trait().map(|it| TypeRef::from_ast(&lower_ctx, it));
-        let target_type = TypeRef::from_ast_opt(&lower_ctx, src.value.target_type());
-        let is_negative = src.value.excl_token().is_some();
+        let item_tree = db.item_tree(impl_loc.id.file_id);
+        let impl_def = &item_tree[impl_loc.id.value];
+        let target_trait = impl_def.target_trait.clone();
+        let target_type = impl_def.target_type.clone();
+        let is_negative = impl_def.is_negative;
         let module_id = impl_loc.container.module(db);
         let container = AssocContainerId::ImplId(id);
+        let mut expander = Expander::new(db, impl_loc.id.file_id, module_id);
 
-        let mut items: Vec<AssocItemId> = Vec::new();
-
-        if let Some(item_list) = src.value.item_list() {
-            let mut expander = Expander::new(db, impl_loc.ast_id.file_id, module_id);
-            items.extend(
-                collect_items(db, &mut expander, item_list.assoc_items(), src.file_id, container)
-                    .into_iter()
-                    .map(|(_, item)| item),
-            );
-            items.extend(
-                collect_items_in_macros(db, &mut expander, &src.with_value(item_list), container)
-                    .into_iter()
-                    .map(|(_, item)| item),
-            );
-        }
+        let items = collect_items(
+            db,
+            module_id,
+            &mut expander,
+            impl_def.items.iter().copied(),
+            impl_loc.id.file_id,
+            container,
+            100,
+        );
+        let items = items.into_iter().map(|(_, item)| item).collect();
 
-        let res = ImplData { target_trait, target_type, items, is_negative };
-        Arc::new(res)
+        Arc::new(ImplData { target_trait, target_type, items, is_negative })
     }
 }
 
@@ -246,22 +171,14 @@ pub struct ConstData {
 impl ConstData {
     pub(crate) fn const_data_query(db: &dyn DefDatabase, konst: ConstId) -> Arc<ConstData> {
         let loc = konst.lookup(db);
-        let node = loc.source(db);
-        let vis_default = RawVisibility::default_for_container(loc.container);
-        Arc::new(ConstData::new(db, vis_default, node))
-    }
+        let item_tree = db.item_tree(loc.id.file_id);
+        let konst = &item_tree[loc.id.value];
 
-    fn new<N: NameOwner + TypeAscriptionOwner + VisibilityOwner>(
-        db: &dyn DefDatabase,
-        vis_default: RawVisibility,
-        node: InFile<N>,
-    ) -> ConstData {
-        let ctx = LowerCtx::new(db, node.file_id);
-        let name = node.value.name().map(|n| n.as_name());
-        let type_ref = TypeRef::from_ast_opt(&ctx, node.value.ascribed_type());
-        let visibility =
-            RawVisibility::from_ast_with_default(db, vis_default, node.map(|n| n.visibility()));
-        ConstData { name, type_ref, visibility }
+        Arc::new(ConstData {
+            name: konst.name.clone(),
+            type_ref: konst.type_ref.clone(),
+            visibility: item_tree[konst.visibility].clone(),
+        })
     }
 }
 
@@ -275,44 +192,25 @@ pub struct StaticData {
 
 impl StaticData {
     pub(crate) fn static_data_query(db: &dyn DefDatabase, konst: StaticId) -> Arc<StaticData> {
-        let node = konst.lookup(db).source(db);
-        let ctx = LowerCtx::new(db, node.file_id);
-
-        let name = node.value.name().map(|n| n.as_name());
-        let type_ref = TypeRef::from_ast_opt(&ctx, node.value.ascribed_type());
-        let mutable = node.value.mut_token().is_some();
-        let visibility = RawVisibility::from_ast_with_default(
-            db,
-            RawVisibility::private(),
-            node.map(|n| n.visibility()),
-        );
-
-        Arc::new(StaticData { name, type_ref, visibility, mutable })
-    }
-}
-
-fn collect_items_in_macros(
-    db: &dyn DefDatabase,
-    expander: &mut Expander,
-    impl_def: &InFile<ast::ItemList>,
-    container: AssocContainerId,
-) -> Vec<(Name, AssocItemId)> {
-    let mut res = Vec::new();
-
-    // We set a limit to protect against infinite recursion
-    let limit = 100;
-
-    for m in impl_def.value.syntax().children().filter_map(ast::MacroCall::cast) {
-        res.extend(collect_items_in_macro(db, expander, m, container, limit))
+        let node = konst.lookup(db);
+        let item_tree = db.item_tree(node.id.file_id);
+        let statik = &item_tree[node.id.value];
+
+        Arc::new(StaticData {
+            name: Some(statik.name.clone()),
+            type_ref: statik.type_ref.clone(),
+            visibility: item_tree[statik.visibility].clone(),
+            mutable: statik.mutable,
+        })
     }
-
-    res
 }
 
-fn collect_items_in_macro(
+fn collect_items(
     db: &dyn DefDatabase,
+    module: ModuleId,
     expander: &mut Expander,
-    m: ast::MacroCall,
+    assoc_items: impl Iterator<Item = AssocItem>,
+    file_id: crate::HirFileId,
     container: AssocContainerId,
     limit: usize,
 ) -> Vec<(Name, AssocItemId)> {
@@ -320,62 +218,62 @@ fn collect_items_in_macro(
         return Vec::new();
     }
 
-    if let Some((mark, items)) = expander.enter_expand(db, None, m) {
-        let items: InFile<ast::MacroItems> = expander.to_source(items);
-        let mut res = collect_items(
-            db,
-            expander,
-            items.value.items().filter_map(|it| AssocItem::cast(it.syntax().clone())),
-            items.file_id,
-            container,
-        );
-
-        // Recursive collect macros
-        // Note that ast::ModuleItem do not include ast::MacroCall
-        // We cannot use ModuleItemOwner::items here
-        for it in items.value.syntax().children().filter_map(ast::MacroCall::cast) {
-            res.extend(collect_items_in_macro(db, expander, it, container, limit - 1))
-        }
-        expander.exit(db, mark);
-        res
-    } else {
-        Vec::new()
-    }
-}
-
-fn collect_items(
-    db: &dyn DefDatabase,
-    expander: &mut Expander,
-    assoc_items: impl Iterator<Item = AssocItem>,
-    file_id: crate::HirFileId,
-    container: AssocContainerId,
-) -> Vec<(Name, AssocItemId)> {
-    let items = db.ast_id_map(file_id);
-
-    assoc_items
-        .filter_map(|item_node| match item_node {
-            ast::AssocItem::FnDef(it) => {
-                let name = it.name().map_or_else(Name::missing, |it| it.as_name());
-                if !expander.is_cfg_enabled(&it) {
-                    return None;
+    let item_tree = db.item_tree(file_id);
+    let cfg_options = db.crate_graph()[module.krate].cfg_options.clone();
+
+    let mut items = Vec::new();
+    for item in assoc_items {
+        match item {
+            AssocItem::Function(id) => {
+                let item = &item_tree[id];
+                let attrs = item_tree.attrs(ModItem::from(id).into());
+                if !attrs.is_cfg_enabled(&cfg_options) {
+                    continue;
                 }
-                let def = FunctionLoc { container, ast_id: AstId::new(file_id, items.ast_id(&it)) }
-                    .intern(db);
-                Some((name, def.into()))
+                let def = FunctionLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((item.name.clone(), def.into()));
             }
-            ast::AssocItem::ConstDef(it) => {
-                let name = it.name().map_or_else(Name::missing, |it| it.as_name());
-                let def = ConstLoc { container, ast_id: AstId::new(file_id, items.ast_id(&it)) }
-                    .intern(db);
-                Some((name, def.into()))
+            // FIXME: cfg?
+            AssocItem::Const(id) => {
+                let item = &item_tree[id];
+                let name = match item.name.clone() {
+                    Some(name) => name,
+                    None => continue,
+                };
+                let def = ConstLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((name, def.into()));
             }
-            ast::AssocItem::TypeAliasDef(it) => {
-                let name = it.name().map_or_else(Name::missing, |it| it.as_name());
-                let def =
-                    TypeAliasLoc { container, ast_id: AstId::new(file_id, items.ast_id(&it)) }
-                        .intern(db);
-                Some((name, def.into()))
+            AssocItem::TypeAlias(id) => {
+                let item = &item_tree[id];
+                let def = TypeAliasLoc { container, id: ItemTreeId::new(file_id, id) }.intern(db);
+                items.push((item.name.clone(), def.into()));
             }
-        })
-        .collect()
+            AssocItem::MacroCall(call) => {
+                let call = &item_tree[call];
+                let ast_id_map = db.ast_id_map(file_id);
+                let root = db.parse_or_expand(file_id).unwrap();
+                let call = ast_id_map.get(call.ast_id).to_node(&root);
+
+                if let Some((mark, mac)) = expander.enter_expand(db, None, call) {
+                    let src: InFile<ast::MacroItems> = expander.to_source(mac);
+                    let item_tree = db.item_tree(src.file_id);
+                    let iter =
+                        item_tree.top_level_items().iter().filter_map(ModItem::as_assoc_item);
+                    items.extend(collect_items(
+                        db,
+                        module,
+                        expander,
+                        iter,
+                        src.file_id,
+                        container,
+                        limit - 1,
+                    ));
+
+                    expander.exit(db, mark);
+                }
+            }
+        }
+    }
+
+    items
 }
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index 945a0025e..9c3ede2d7 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -1,7 +1,7 @@
 //! Defines database & queries for name resolution.
 use std::sync::Arc;
 
-use hir_expand::{db::AstDatabase, name::Name, HirFileId};
+use hir_expand::{db::AstDatabase, HirFileId};
 use ra_db::{salsa, CrateId, SourceDatabase, Upcast};
 use ra_prof::profile;
 use ra_syntax::SmolStr;
@@ -12,13 +12,11 @@ use crate::{
     body::{scope::ExprScopes, Body, BodySourceMap},
     data::{ConstData, FunctionData, ImplData, StaticData, TraitData, TypeAliasData},
     docs::Documentation,
-    find_path,
     generics::GenericParams,
-    item_scope::ItemInNs,
+    import_map::ImportMap,
+    item_tree::ItemTree,
     lang_item::{LangItemTarget, LangItems},
-    nameres::{raw::RawItems, CrateDefMap},
-    path::ModPath,
-    visibility::Visibility,
+    nameres::CrateDefMap,
     AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, EnumLoc, FunctionId, FunctionLoc,
     GenericDefId, ImplId, ImplLoc, ModuleId, StaticId, StaticLoc, StructId, StructLoc, TraitId,
     TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc,
@@ -48,8 +46,8 @@ pub trait InternDatabase: SourceDatabase {
 
 #[salsa::query_group(DefDatabaseStorage)]
 pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
-    #[salsa::invoke(RawItems::raw_items_query)]
-    fn raw_items(&self, file_id: HirFileId) -> Arc<RawItems>;
+    #[salsa::invoke(ItemTree::item_tree_query)]
+    fn item_tree(&self, file_id: HirFileId) -> Arc<ItemTree>;
 
     #[salsa::invoke(crate_def_map_wait)]
     #[salsa::transparent]
@@ -113,15 +111,8 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
     #[salsa::invoke(Documentation::documentation_query)]
     fn documentation(&self, def: AttrDefId) -> Option<Documentation>;
 
-    #[salsa::invoke(find_path::importable_locations_of_query)]
-    fn importable_locations_of(
-        &self,
-        item: ItemInNs,
-        krate: CrateId,
-    ) -> Arc<[(ModuleId, Name, Visibility)]>;
-
-    #[salsa::invoke(find_path::find_path_inner_query)]
-    fn find_path_inner(&self, item: ItemInNs, from: ModuleId, max_len: usize) -> Option<ModPath>;
+    #[salsa::invoke(ImportMap::import_map_query)]
+    fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 }
 
 fn crate_def_map_wait(db: &impl DefDatabase, krate: CrateId) -> Arc<CrateDefMap> {
diff --git a/crates/ra_hir_def/src/diagnostics.rs b/crates/ra_hir_def/src/diagnostics.rs
index 510c5e064..30db48f86 100644
--- a/crates/ra_hir_def/src/diagnostics.rs
+++ b/crates/ra_hir_def/src/diagnostics.rs
@@ -3,7 +3,6 @@
 use std::any::Any;
 
 use hir_expand::diagnostics::Diagnostic;
-use ra_db::RelativePathBuf;
 use ra_syntax::{ast, AstPtr, SyntaxNodePtr};
 
 use hir_expand::{HirFileId, InFile};
@@ -12,7 +11,7 @@ use hir_expand::{HirFileId, InFile};
 pub struct UnresolvedModule {
     pub file: HirFileId,
     pub decl: AstPtr<ast::Module>,
-    pub candidate: RelativePathBuf,
+    pub candidate: String,
 }
 
 impl Diagnostic for UnresolvedModule {
diff --git a/crates/ra_hir_def/src/docs.rs b/crates/ra_hir_def/src/docs.rs
index b221ae1ce..2630b3d89 100644
--- a/crates/ra_hir_def/src/docs.rs
+++ b/crates/ra_hir_def/src/docs.rs
@@ -29,6 +29,13 @@ impl Documentation {
         Documentation(s.into())
     }
 
+    pub fn from_ast<N>(node: &N) -> Option<Documentation>
+    where
+        N: ast::DocCommentsOwner + ast::AttrsOwner,
+    {
+        docs_from_ast(node)
+    }
+
     pub fn as_str(&self) -> &str {
         &*self.0
     }
@@ -70,6 +77,45 @@ impl Documentation {
     }
 }
 
-pub(crate) fn docs_from_ast(node: &impl ast::DocCommentsOwner) -> Option<Documentation> {
-    node.doc_comment_text().map(|it| Documentation::new(&it))
+pub(crate) fn docs_from_ast<N>(node: &N) -> Option<Documentation>
+where
+    N: ast::DocCommentsOwner + ast::AttrsOwner,
+{
+    let doc_comment_text = node.doc_comment_text();
+    let doc_attr_text = expand_doc_attrs(node);
+    let docs = merge_doc_comments_and_attrs(doc_comment_text, doc_attr_text);
+    docs.map(|it| Documentation::new(&it))
+}
+
+fn merge_doc_comments_and_attrs(
+    doc_comment_text: Option<String>,
+    doc_attr_text: Option<String>,
+) -> Option<String> {
+    match (doc_comment_text, doc_attr_text) {
+        (Some(mut comment_text), Some(attr_text)) => {
+            comment_text.push_str("\n\n");
+            comment_text.push_str(&attr_text);
+            Some(comment_text)
+        }
+        (Some(comment_text), None) => Some(comment_text),
+        (None, Some(attr_text)) => Some(attr_text),
+        (None, None) => None,
+    }
+}
+
+fn expand_doc_attrs(owner: &dyn ast::AttrsOwner) -> Option<String> {
+    let mut docs = String::new();
+    for attr in owner.attrs() {
+        if let Some(("doc", value)) =
+            attr.as_simple_key_value().as_ref().map(|(k, v)| (k.as_str(), v.as_str()))
+        {
+            docs.push_str(value);
+            docs.push_str("\n\n");
+        }
+    }
+    if docs.is_empty() {
+        None
+    } else {
+        Some(docs.trim_end_matches("\n\n").to_owned())
+    }
 }
diff --git a/crates/ra_hir_def/src/expr.rs b/crates/ra_hir_def/src/expr.rs
index ca49b26d1..e41cfc16b 100644
--- a/crates/ra_hir_def/src/expr.rs
+++ b/crates/ra_hir_def/src/expr.rs
@@ -150,6 +150,9 @@ pub enum Expr {
     Tuple {
         exprs: Vec<ExprId>,
     },
+    Unsafe {
+        body: ExprId,
+    },
     Array(Array),
     Literal(Literal),
 }
@@ -247,7 +250,7 @@ impl Expr {
                     f(*expr);
                 }
             }
-            Expr::TryBlock { body } => f(*body),
+            Expr::TryBlock { body } | Expr::Unsafe { body } => f(*body),
             Expr::Loop { body, .. } => f(*body),
             Expr::While { condition, body, .. } => {
                 f(*condition);
diff --git a/crates/ra_hir_def/src/find_path.rs b/crates/ra_hir_def/src/find_path.rs
index 4db798473..06701a830 100644
--- a/crates/ra_hir_def/src/find_path.rs
+++ b/crates/ra_hir_def/src/find_path.rs
@@ -1,9 +1,8 @@
 //! An algorithm to find a path to refer to a certain item.
 
-use std::sync::Arc;
-
 use hir_expand::name::{known, AsName, Name};
 use ra_prof::profile;
+use rustc_hash::FxHashSet;
 use test_utils::mark;
 
 use crate::{
@@ -11,7 +10,7 @@ use crate::{
     item_scope::ItemInNs,
     path::{ModPath, PathKind},
     visibility::Visibility,
-    CrateId, ModuleDefId, ModuleId,
+    ModuleDefId, ModuleId,
 };
 
 // FIXME: handle local items
@@ -20,7 +19,7 @@ use crate::{
 /// *from where* you're referring to the item, hence the `from` parameter.
 pub fn find_path(db: &dyn DefDatabase, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
     let _p = profile("find_path");
-    db.find_path_inner(item, from, MAX_PATH_LEN)
+    find_path_inner(db, item, from, MAX_PATH_LEN)
 }
 
 const MAX_PATH_LEN: usize = 15;
@@ -36,20 +35,9 @@ impl ModPath {
         let first_segment = self.segments.first();
         first_segment == Some(&known::alloc) || first_segment == Some(&known::core)
     }
-
-    fn len(&self) -> usize {
-        self.segments.len()
-            + match self.kind {
-                PathKind::Plain => 0,
-                PathKind::Super(i) => i as usize,
-                PathKind::Crate => 1,
-                PathKind::Abs => 0,
-                PathKind::DollarCrate(_) => 1,
-            }
-    }
 }
 
-pub(crate) fn find_path_inner_query(
+fn find_path_inner(
     db: &dyn DefDatabase,
     item: ItemInNs,
     from: ModuleId,
@@ -133,31 +121,67 @@ pub(crate) fn find_path_inner_query(
     }
 
     // - otherwise, look for modules containing (reexporting) it and import it from one of those
+
     let crate_root = ModuleId { local_id: def_map.root, krate: from.krate };
     let crate_attrs = db.attrs(crate_root.into());
     let prefer_no_std = crate_attrs.by_key("no_std").exists();
-    let importable_locations = find_importable_locations(db, item, from);
     let mut best_path = None;
     let mut best_path_len = max_len;
-    for (module_id, name) in importable_locations {
-        let mut path = match db.find_path_inner(
-            ItemInNs::Types(ModuleDefId::ModuleId(module_id)),
-            from,
-            best_path_len - 1,
-        ) {
-            None => continue,
-            Some(path) => path,
-        };
-        path.segments.push(name);
 
-        let new_path = if let Some(best_path) = best_path {
-            select_best_path(best_path, path, prefer_no_std)
-        } else {
-            path
-        };
-        best_path_len = new_path.len();
-        best_path = Some(new_path);
+    if item.krate(db) == Some(from.krate) {
+        // Item was defined in the same crate that wants to import it. It cannot be found in any
+        // dependency in this case.
+
+        let local_imports = find_local_import_locations(db, item, from);
+        for (module_id, name) in local_imports {
+            if let Some(mut path) = find_path_inner(
+                db,
+                ItemInNs::Types(ModuleDefId::ModuleId(module_id)),
+                from,
+                best_path_len - 1,
+            ) {
+                path.segments.push(name);
+
+                let new_path = if let Some(best_path) = best_path {
+                    select_best_path(best_path, path, prefer_no_std)
+                } else {
+                    path
+                };
+                best_path_len = new_path.len();
+                best_path = Some(new_path);
+            }
+        }
+    } else {
+        // Item was defined in some upstream crate. This means that it must be exported from one,
+        // too (unless we can't name it at all). It could *also* be (re)exported by the same crate
+        // that wants to import it here, but we always prefer to use the external path here.
+
+        let crate_graph = db.crate_graph();
+        let extern_paths = crate_graph[from.krate].dependencies.iter().filter_map(|dep| {
+            let import_map = db.import_map(dep.crate_id);
+            import_map.import_info_for(item).and_then(|info| {
+                // Determine best path for containing module and append last segment from `info`.
+                let mut path = find_path_inner(
+                    db,
+                    ItemInNs::Types(ModuleDefId::ModuleId(info.container)),
+                    from,
+                    best_path_len - 1,
+                )?;
+                path.segments.push(info.path.segments.last().unwrap().clone());
+                Some(path)
+            })
+        });
+
+        for path in extern_paths {
+            let new_path = if let Some(best_path) = best_path {
+                select_best_path(best_path, path, prefer_no_std)
+            } else {
+                path
+            };
+            best_path = Some(new_path);
+        }
     }
+
     best_path
 }
 
@@ -185,69 +209,86 @@ fn select_best_path(old_path: ModPath, new_path: ModPath, prefer_no_std: bool) -
     }
 }
 
-fn find_importable_locations(
+/// Finds locations in `from.krate` from which `item` can be imported by `from`.
+fn find_local_import_locations(
     db: &dyn DefDatabase,
     item: ItemInNs,
     from: ModuleId,
 ) -> Vec<(ModuleId, Name)> {
-    let crate_graph = db.crate_graph();
-    let mut result = Vec::new();
-    // We only look in the crate from which we are importing, and the direct
-    // dependencies. We cannot refer to names from transitive dependencies
-    // directly (only through reexports in direct dependencies).
-    for krate in Some(from.krate)
-        .into_iter()
-        .chain(crate_graph[from.krate].dependencies.iter().map(|dep| dep.crate_id))
-    {
-        result.extend(
-            db.importable_locations_of(item, krate)
-                .iter()
-                .filter(|(_, _, vis)| vis.is_visible_from(db, from))
-                .map(|(m, n, _)| (*m, n.clone())),
-        );
-    }
-    result
-}
+    let _p = profile("find_local_import_locations");
+
+    // `from` can import anything below `from` with visibility of at least `from`, and anything
+    // above `from` with any visibility. That means we do not need to descend into private siblings
+    // of `from` (and similar).
+
+    let def_map = db.crate_def_map(from.krate);
+
+    // Compute the initial worklist. We start with all direct child modules of `from` as well as all
+    // of its (recursive) parent modules.
+    let data = &def_map.modules[from.local_id];
+    let mut worklist = data
+        .children
+        .values()
+        .map(|child| ModuleId { krate: from.krate, local_id: *child })
+        .collect::<Vec<_>>();
+    let mut parent = data.parent;
+    while let Some(p) = parent {
+        worklist.push(ModuleId { krate: from.krate, local_id: p });
+        parent = def_map.modules[p].parent;
+    }
+
+    let mut seen: FxHashSet<_> = FxHashSet::default();
+
+    let mut locations = Vec::new();
+    while let Some(module) = worklist.pop() {
+        if !seen.insert(module) {
+            continue; // already processed this module
+        }
+
+        let ext_def_map;
+        let data = if module.krate == from.krate {
+            &def_map[module.local_id]
+        } else {
+            // The crate might reexport a module defined in another crate.
+            ext_def_map = db.crate_def_map(module.krate);
+            &ext_def_map[module.local_id]
+        };
 
-/// Collects all locations from which we might import the item in a particular
-/// crate. These include the original definition of the item, and any
-/// non-private `use`s.
-///
-/// Note that the crate doesn't need to be the one in which the item is defined;
-/// it might be re-exported in other crates.
-pub(crate) fn importable_locations_of_query(
-    db: &dyn DefDatabase,
-    item: ItemInNs,
-    krate: CrateId,
-) -> Arc<[(ModuleId, Name, Visibility)]> {
-    let _p = profile("importable_locations_of_query");
-    let def_map = db.crate_def_map(krate);
-    let mut result = Vec::new();
-    for (local_id, data) in def_map.modules.iter() {
         if let Some((name, vis)) = data.scope.name_of(item) {
-            let is_private = if let Visibility::Module(private_to) = vis {
-                private_to.local_id == local_id
-            } else {
-                false
-            };
-            let is_original_def = if let Some(module_def_id) = item.as_module_def_id() {
-                data.scope.declarations().any(|it| it == module_def_id)
-            } else {
-                false
-            };
-            if is_private && !is_original_def {
+            if vis.is_visible_from(db, from) {
+                let is_private = if let Visibility::Module(private_to) = vis {
+                    private_to.local_id == module.local_id
+                } else {
+                    false
+                };
+                let is_original_def = if let Some(module_def_id) = item.as_module_def_id() {
+                    data.scope.declarations().any(|it| it == module_def_id)
+                } else {
+                    false
+                };
+
                 // Ignore private imports. these could be used if we are
                 // in a submodule of this module, but that's usually not
                 // what the user wants; and if this module can import
                 // the item and we're a submodule of it, so can we.
                 // Also this keeps the cached data smaller.
-                continue;
+                if !is_private || is_original_def {
+                    locations.push((module, name.clone()));
+                }
+            }
+        }
+
+        // Descend into all modules visible from `from`.
+        for (_, per_ns) in data.scope.entries() {
+            if let Some((ModuleDefId::ModuleId(module), vis)) = per_ns.take_types_vis() {
+                if vis.is_visible_from(db, from) {
+                    worklist.push(module);
+                }
             }
-            result.push((ModuleId { krate, local_id }, name.clone(), vis));
         }
     }
 
-    Arc::from(result)
+    locations
 }
 
 #[cfg(test)]
@@ -264,8 +305,8 @@ mod tests {
     /// `code` needs to contain a cursor marker; checks that `find_path` for the
     /// item the `path` refers to returns that same path when called from the
     /// module the cursor is in.
-    fn check_found_path(code: &str, path: &str) {
-        let (db, pos) = TestDB::with_position(code);
+    fn check_found_path(ra_fixture: &str, path: &str) {
+        let (db, pos) = TestDB::with_position(ra_fixture);
         let module = db.module_for_file(pos.file_id);
         let parsed_path_file = ra_syntax::SourceFile::parse(&format!("use {};", path));
         let ast_path = parsed_path_file
@@ -396,6 +437,44 @@ mod tests {
     }
 
     #[test]
+    fn partially_imported() {
+        // Tests that short paths are used even for external items, when parts of the path are
+        // already in scope.
+        check_found_path(
+            r#"
+            //- /main.rs crate:main deps:ra_syntax
+
+            use ra_syntax::ast;
+            <|>
+
+            //- /lib.rs crate:ra_syntax
+            pub mod ast {
+                pub enum ModuleItem {
+                    A, B, C,
+                }
+            }
+        "#,
+            "ast::ModuleItem",
+        );
+
+        check_found_path(
+            r#"
+            //- /main.rs crate:main deps:ra_syntax
+
+            <|>
+
+            //- /lib.rs crate:ra_syntax
+            pub mod ast {
+                pub enum ModuleItem {
+                    A, B, C,
+                }
+            }
+        "#,
+            "ra_syntax::ast::ModuleItem",
+        );
+    }
+
+    #[test]
     fn same_crate_reexport() {
         let code = r#"
             //- /main.rs
diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs
index 09a5241f7..6a0f493a7 100644
--- a/crates/ra_hir_def/src/generics.rs
+++ b/crates/ra_hir_def/src/generics.rs
@@ -42,7 +42,7 @@ pub enum TypeParamProvenance {
 }
 
 /// Data about the generic parameters of a function, struct, impl, etc.
-#[derive(Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug, Default)]
 pub struct GenericParams {
     pub types: Arena<TypeParamData>,
     // lifetimes: Arena<LocalLifetimeParamId, LifetimeParamData>,
@@ -74,8 +74,53 @@ impl GenericParams {
         def: GenericDefId,
     ) -> Arc<GenericParams> {
         let _p = profile("generic_params_query");
-        let (params, _source_map) = GenericParams::new(db, def);
-        Arc::new(params)
+
+        let generics = match def {
+            GenericDefId::FunctionId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::AdtId(AdtId::StructId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::AdtId(AdtId::EnumId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::AdtId(AdtId::UnionId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::TraitId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::TypeAliasId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::ImplId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                tree[item.generic_params].clone()
+            }
+            GenericDefId::EnumVariantId(_) | GenericDefId::ConstId(_) => GenericParams::default(),
+        };
+        Arc::new(generics)
     }
 
     fn new(db: &dyn DefDatabase, def: GenericDefId) -> (GenericParams, InFile<SourceMap>) {
@@ -156,7 +201,12 @@ impl GenericParams {
         (generics, InFile::new(file_id, sm))
     }
 
-    fn fill(&mut self, lower_ctx: &LowerCtx, sm: &mut SourceMap, node: &dyn TypeParamsOwner) {
+    pub(crate) fn fill(
+        &mut self,
+        lower_ctx: &LowerCtx,
+        sm: &mut SourceMap,
+        node: &dyn TypeParamsOwner,
+    ) {
         if let Some(params) = node.type_param_list() {
             self.fill_params(lower_ctx, sm, params)
         }
@@ -165,7 +215,7 @@ impl GenericParams {
         }
     }
 
-    fn fill_bounds(
+    pub(crate) fn fill_bounds(
         &mut self,
         lower_ctx: &LowerCtx,
         node: &dyn ast::TypeBoundsOwner,
@@ -229,7 +279,7 @@ impl GenericParams {
             .push(WherePredicate { target: WherePredicateTarget::TypeRef(type_ref), bound });
     }
 
-    fn fill_implicit_impl_trait_args(&mut self, type_ref: &TypeRef) {
+    pub(crate) fn fill_implicit_impl_trait_args(&mut self, type_ref: &TypeRef) {
         type_ref.walk(&mut |type_ref| {
             if let TypeRef::ImplTrait(bounds) = type_ref {
                 let param = TypeParamData {
diff --git a/crates/ra_hir_def/src/import_map.rs b/crates/ra_hir_def/src/import_map.rs
new file mode 100644
index 000000000..869f3ca5a
--- /dev/null
+++ b/crates/ra_hir_def/src/import_map.rs
@@ -0,0 +1,737 @@
+//! A map of all publicly exported items in a crate.
+
+use std::{cmp::Ordering, fmt, hash::BuildHasherDefault, sync::Arc};
+
+use fst::{self, Streamer};
+use indexmap::{map::Entry, IndexMap};
+use ra_db::CrateId;
+use ra_syntax::SmolStr;
+use rustc_hash::{FxHashMap, FxHasher};
+use smallvec::SmallVec;
+
+use crate::{
+    db::DefDatabase,
+    item_scope::ItemInNs,
+    path::{ModPath, PathKind},
+    visibility::Visibility,
+    AssocItemId, ModuleDefId, ModuleId, TraitId,
+};
+
+type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
+
+/// Item import details stored in the `ImportMap`.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ImportInfo {
+    /// A path that can be used to import the item, relative to the crate's root.
+    pub path: ModPath,
+    /// The module containing this item.
+    pub container: ModuleId,
+}
+
+/// A map from publicly exported items to the path needed to import/name them from a downstream
+/// crate.
+///
+/// Reexports of items are taken into account, ie. if something is exported under multiple
+/// names, the one with the shortest import path will be used.
+///
+/// Note that all paths are relative to the containing crate's root, so the crate name still needs
+/// to be prepended to the `ModPath` before the path is valid.
+#[derive(Default)]
+pub struct ImportMap {
+    map: FxIndexMap<ItemInNs, ImportInfo>,
+
+    /// List of keys stored in `map`, sorted lexicographically by their `ModPath`. Indexed by the
+    /// values returned by running `fst`.
+    ///
+    /// Since a path can refer to multiple items due to namespacing, we store all items with the
+    /// same path right after each other. This allows us to find all items after the FST gives us
+    /// the index of the first one.
+    importables: Vec<ItemInNs>,
+    fst: fst::Map<Vec<u8>>,
+
+    /// Maps names of associated items to the item's ID. Only includes items whose defining trait is
+    /// exported.
+    assoc_map: FxHashMap<SmolStr, SmallVec<[AssocItemId; 1]>>,
+}
+
+impl ImportMap {
+    pub fn import_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<Self> {
+        let _p = ra_prof::profile("import_map_query");
+        let def_map = db.crate_def_map(krate);
+        let mut import_map = Self::default();
+
+        // We look only into modules that are public(ly reexported), starting with the crate root.
+        let empty = ModPath { kind: PathKind::Plain, segments: vec![] };
+        let root = ModuleId { krate, local_id: def_map.root };
+        let mut worklist = vec![(root, empty)];
+        while let Some((module, mod_path)) = worklist.pop() {
+            let ext_def_map;
+            let mod_data = if module.krate == krate {
+                &def_map[module.local_id]
+            } else {
+                // The crate might reexport a module defined in another crate.
+                ext_def_map = db.crate_def_map(module.krate);
+                &ext_def_map[module.local_id]
+            };
+
+            let visible_items = mod_data.scope.entries().filter_map(|(name, per_ns)| {
+                let per_ns = per_ns.filter_visibility(|vis| vis == Visibility::Public);
+                if per_ns.is_none() {
+                    None
+                } else {
+                    Some((name, per_ns))
+                }
+            });
+
+            for (name, per_ns) in visible_items {
+                let mk_path = || {
+                    let mut path = mod_path.clone();
+                    path.segments.push(name.clone());
+                    path
+                };
+
+                for item in per_ns.iter_items() {
+                    let path = mk_path();
+                    match import_map.map.entry(item) {
+                        Entry::Vacant(entry) => {
+                            entry.insert(ImportInfo { path, container: module });
+                        }
+                        Entry::Occupied(mut entry) => {
+                            // If the new path is shorter, prefer that one.
+                            if path.len() < entry.get().path.len() {
+                                *entry.get_mut() = ImportInfo { path, container: module };
+                            } else {
+                                continue;
+                            }
+                        }
+                    }
+
+                    // If we've just added a path to a module, descend into it. We might traverse
+                    // modules multiple times, but only if the new path to it is shorter than the
+                    // first (else we `continue` above).
+                    if let Some(ModuleDefId::ModuleId(mod_id)) = item.as_module_def_id() {
+                        worklist.push((mod_id, mk_path()));
+                    }
+
+                    // If we've added a path to a trait, add the trait's methods to the method map.
+                    if let Some(ModuleDefId::TraitId(tr)) = item.as_module_def_id() {
+                        import_map.collect_trait_methods(db, tr);
+                    }
+                }
+            }
+        }
+
+        let mut importables = import_map.map.iter().collect::<Vec<_>>();
+
+        importables.sort_by(cmp);
+
+        // Build the FST, taking care not to insert duplicate values.
+
+        let mut builder = fst::MapBuilder::memory();
+        let mut last_batch_start = 0;
+
+        for idx in 0..importables.len() {
+            if let Some(next_item) = importables.get(idx + 1) {
+                if cmp(&importables[last_batch_start], next_item) == Ordering::Equal {
+                    continue;
+                }
+            }
+
+            let start = last_batch_start;
+            last_batch_start = idx + 1;
+
+            let key = fst_path(&importables[start].1.path);
+
+            builder.insert(key, start as u64).unwrap();
+        }
+
+        import_map.fst = fst::Map::new(builder.into_inner().unwrap()).unwrap();
+        import_map.importables = importables.iter().map(|(item, _)| **item).collect();
+
+        Arc::new(import_map)
+    }
+
+    /// Returns the `ModPath` needed to import/mention `item`, relative to this crate's root.
+    pub fn path_of(&self, item: ItemInNs) -> Option<&ModPath> {
+        Some(&self.map.get(&item)?.path)
+    }
+
+    pub fn import_info_for(&self, item: ItemInNs) -> Option<&ImportInfo> {
+        self.map.get(&item)
+    }
+
+    fn collect_trait_methods(&mut self, db: &dyn DefDatabase, tr: TraitId) {
+        let data = db.trait_data(tr);
+        for (name, item) in data.items.iter() {
+            self.assoc_map.entry(name.to_string().into()).or_default().push(*item);
+        }
+    }
+}
+
+impl PartialEq for ImportMap {
+    fn eq(&self, other: &Self) -> bool {
+        // `fst` and `importables` are built from `map`, so we don't need to compare them.
+        self.map == other.map
+    }
+}
+
+impl Eq for ImportMap {}
+
+impl fmt::Debug for ImportMap {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut importable_paths: Vec<_> = self
+            .map
+            .iter()
+            .map(|(item, info)| {
+                let ns = match item {
+                    ItemInNs::Types(_) => "t",
+                    ItemInNs::Values(_) => "v",
+                    ItemInNs::Macros(_) => "m",
+                };
+                format!("- {} ({})", info.path, ns)
+            })
+            .collect();
+
+        importable_paths.sort();
+        f.write_str(&importable_paths.join("\n"))
+    }
+}
+
+fn fst_path(path: &ModPath) -> String {
+    let mut s = path.to_string();
+    s.make_ascii_lowercase();
+    s
+}
+
+fn cmp((_, lhs): &(&ItemInNs, &ImportInfo), (_, rhs): &(&ItemInNs, &ImportInfo)) -> Ordering {
+    let lhs_str = fst_path(&lhs.path);
+    let rhs_str = fst_path(&rhs.path);
+    lhs_str.cmp(&rhs_str)
+}
+
+#[derive(Debug)]
+pub struct Query {
+    query: String,
+    lowercased: String,
+    anchor_end: bool,
+    case_sensitive: bool,
+    limit: usize,
+}
+
+impl Query {
+    pub fn new(query: &str) -> Self {
+        Self {
+            lowercased: query.to_lowercase(),
+            query: query.to_string(),
+            anchor_end: false,
+            case_sensitive: false,
+            limit: usize::max_value(),
+        }
+    }
+
+    /// Only returns items whose paths end with the (case-insensitive) query string as their last
+    /// segment.
+    pub fn anchor_end(self) -> Self {
+        Self { anchor_end: true, ..self }
+    }
+
+    /// Limits the returned number of items to `limit`.
+    pub fn limit(self, limit: usize) -> Self {
+        Self { limit, ..self }
+    }
+
+    /// Respect casing of the query string when matching.
+    pub fn case_sensitive(self) -> Self {
+        Self { case_sensitive: true, ..self }
+    }
+}
+
+/// Searches dependencies of `krate` for an importable path matching `query`.
+///
+/// This returns a list of items that could be imported from dependencies of `krate`.
+pub fn search_dependencies<'a>(
+    db: &'a dyn DefDatabase,
+    krate: CrateId,
+    query: Query,
+) -> Vec<ItemInNs> {
+    let _p = ra_prof::profile("search_dependencies").detail(|| format!("{:?}", query));
+
+    let graph = db.crate_graph();
+    let import_maps: Vec<_> =
+        graph[krate].dependencies.iter().map(|dep| db.import_map(dep.crate_id)).collect();
+
+    let automaton = fst::automaton::Subsequence::new(&query.lowercased);
+
+    let mut op = fst::map::OpBuilder::new();
+    for map in &import_maps {
+        op = op.add(map.fst.search(&automaton));
+    }
+
+    let mut stream = op.union();
+    let mut res = Vec::new();
+    while let Some((_, indexed_values)) = stream.next() {
+        for indexed_value in indexed_values {
+            let import_map = &import_maps[indexed_value.index];
+            let importables = &import_map.importables[indexed_value.value as usize..];
+
+            // Path shared by the importable items in this group.
+            let path = &import_map.map[&importables[0]].path;
+
+            if query.anchor_end {
+                // Last segment must match query.
+                let last = path.segments.last().unwrap().to_string();
+                if last.to_lowercase() != query.lowercased {
+                    continue;
+                }
+            }
+
+            // Add the items from this `ModPath` group. Those are all subsequent items in
+            // `importables` whose paths match `path`.
+            let iter = importables.iter().copied().take_while(|item| {
+                let item_path = &import_map.map[item].path;
+                fst_path(item_path) == fst_path(path)
+            });
+
+            if query.case_sensitive {
+                // FIXME: This does not do a subsequence match.
+                res.extend(iter.filter(|item| {
+                    let item_path = &import_map.map[item].path;
+                    item_path.to_string().contains(&query.query)
+                }));
+            } else {
+                res.extend(iter);
+            }
+
+            if res.len() >= query.limit {
+                res.truncate(query.limit);
+                return res;
+            }
+        }
+    }
+
+    // Add all exported associated items whose names match the query (exactly).
+    for map in &import_maps {
+        if let Some(v) = map.assoc_map.get(&*query.query) {
+            res.extend(v.iter().map(|&assoc| {
+                ItemInNs::Types(match assoc {
+                    AssocItemId::FunctionId(it) => it.into(),
+                    AssocItemId::ConstId(it) => it.into(),
+                    AssocItemId::TypeAliasId(it) => it.into(),
+                })
+            }));
+        }
+    }
+
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{test_db::TestDB, AssocContainerId, Lookup};
+    use insta::assert_snapshot;
+    use itertools::Itertools;
+    use ra_db::fixture::WithFixture;
+    use ra_db::{SourceDatabase, Upcast};
+
+    fn import_map(ra_fixture: &str) -> String {
+        let db = TestDB::with_files(ra_fixture);
+        let crate_graph = db.crate_graph();
+
+        let s = crate_graph
+            .iter()
+            .filter_map(|krate| {
+                let cdata = &crate_graph[krate];
+                let name = cdata.display_name.as_ref()?;
+
+                let map = db.import_map(krate);
+
+                Some(format!("{}:\n{:?}", name, map))
+            })
+            .join("\n");
+        s
+    }
+
+    fn search_dependencies_of(ra_fixture: &str, krate_name: &str, query: Query) -> String {
+        let db = TestDB::with_files(ra_fixture);
+        let crate_graph = db.crate_graph();
+        let krate = crate_graph
+            .iter()
+            .find(|krate| {
+                crate_graph[*krate].display_name.as_ref().map(|n| n.to_string())
+                    == Some(krate_name.to_string())
+            })
+            .unwrap();
+
+        search_dependencies(db.upcast(), krate, query)
+            .into_iter()
+            .filter_map(|item| {
+                let mark = match item {
+                    ItemInNs::Types(_) => "t",
+                    ItemInNs::Values(_) => "v",
+                    ItemInNs::Macros(_) => "m",
+                };
+                let item = assoc_to_trait(&db, item);
+                item.krate(db.upcast()).map(|krate| {
+                    let map = db.import_map(krate);
+                    let path = map.path_of(item).unwrap();
+                    format!(
+                        "{}::{} ({})",
+                        crate_graph[krate].display_name.as_ref().unwrap(),
+                        path,
+                        mark
+                    )
+                })
+            })
+            .join("\n")
+    }
+
+    fn assoc_to_trait(db: &dyn DefDatabase, item: ItemInNs) -> ItemInNs {
+        let assoc: AssocItemId = match item {
+            ItemInNs::Types(it) | ItemInNs::Values(it) => match it {
+                ModuleDefId::TypeAliasId(it) => it.into(),
+                ModuleDefId::FunctionId(it) => it.into(),
+                ModuleDefId::ConstId(it) => it.into(),
+                _ => return item,
+            },
+            _ => return item,
+        };
+
+        let container = match assoc {
+            AssocItemId::FunctionId(it) => it.lookup(db).container,
+            AssocItemId::ConstId(it) => it.lookup(db).container,
+            AssocItemId::TypeAliasId(it) => it.lookup(db).container,
+        };
+
+        match container {
+            AssocContainerId::TraitId(it) => ItemInNs::Types(it.into()),
+            _ => item,
+        }
+    }
+
+    #[test]
+    fn smoke() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+
+            mod private {
+                pub use lib::Pub;
+                pub struct InPrivateModule;
+            }
+
+            pub mod publ1 {
+                use lib::Pub;
+            }
+
+            pub mod real_pub {
+                pub use lib::Pub;
+            }
+            pub mod real_pu2 { // same path length as above
+                pub use lib::Pub;
+            }
+
+            //- /lib.rs crate:lib
+            pub struct Pub {}
+            pub struct Pub2; // t + v
+            struct Priv;
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - publ1 (t)
+        - real_pu2 (t)
+        - real_pub (t)
+        - real_pub::Pub (t)
+        lib:
+        - Pub (t)
+        - Pub2 (t)
+        - Pub2 (v)
+        "###);
+    }
+
+    #[test]
+    fn prefers_shortest_path() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main
+
+            pub mod sub {
+                pub mod subsub {
+                    pub struct Def {}
+                }
+
+                pub use super::sub::subsub::Def;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - sub (t)
+        - sub::Def (t)
+        - sub::subsub (t)
+        "###);
+    }
+
+    #[test]
+    fn type_reexport_cross_crate() {
+        // Reexports need to be visible from a crate, even if the original crate exports the item
+        // at a shorter path.
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub mod m {
+                pub use lib::S;
+            }
+            //- /lib.rs crate:lib
+            pub struct S;
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - m (t)
+        - m::S (t)
+        - m::S (v)
+        lib:
+        - S (t)
+        - S (v)
+        "###);
+    }
+
+    #[test]
+    fn macro_reexport() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub mod m {
+                pub use lib::pub_macro;
+            }
+            //- /lib.rs crate:lib
+            #[macro_export]
+            macro_rules! pub_macro {
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - m (t)
+        - m::pub_macro (m)
+        lib:
+        - pub_macro (m)
+        "###);
+    }
+
+    #[test]
+    fn module_reexport() {
+        // Reexporting modules from a dependency adds all contents to the import map.
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub use lib::module as reexported_module;
+            //- /lib.rs crate:lib
+            pub mod module {
+                pub struct S;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - reexported_module (t)
+        - reexported_module::S (t)
+        - reexported_module::S (v)
+        lib:
+        - module (t)
+        - module::S (t)
+        - module::S (v)
+        "###);
+    }
+
+    #[test]
+    fn cyclic_module_reexport() {
+        // A cyclic reexport does not hang.
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub mod module {
+                pub struct S;
+                pub use super::sub::*;
+            }
+
+            pub mod sub {
+                pub use super::module;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - module (t)
+        - module::S (t)
+        - module::S (v)
+        - sub (t)
+        "###);
+    }
+
+    #[test]
+    fn private_macro() {
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            macro_rules! private_macro {
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        "###);
+    }
+
+    #[test]
+    fn namespacing() {
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub struct Thing;     // t + v
+            #[macro_export]
+            macro_rules! Thing {  // m
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - Thing (m)
+        - Thing (t)
+        - Thing (v)
+        "###);
+
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub mod Thing {}      // t
+            #[macro_export]
+            macro_rules! Thing {  // m
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - Thing (m)
+        - Thing (t)
+        "###);
+    }
+
+    #[test]
+    fn search() {
+        let ra_fixture = r#"
+            //- /main.rs crate:main deps:dep
+            //- /dep.rs crate:dep deps:tdep
+            use tdep::fmt as fmt_dep;
+            pub mod fmt {
+                pub trait Display {
+                    fn fmt();
+                }
+            }
+            #[macro_export]
+            macro_rules! Fmt {
+                () => {};
+            }
+            pub struct Fmt;
+
+            pub fn format() {}
+            pub fn no() {}
+
+            //- /tdep.rs crate:tdep
+            pub mod fmt {
+                pub struct NotImportableFromMain;
+            }
+        "#;
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("fmt"));
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        dep::Fmt (v)
+        dep::Fmt (m)
+        dep::fmt::Display (t)
+        dep::format (v)
+        dep::fmt::Display (t)
+        "###);
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("fmt").anchor_end());
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        dep::Fmt (v)
+        dep::Fmt (m)
+        dep::fmt::Display (t)
+        "###);
+    }
+
+    #[test]
+    fn search_casing() {
+        let ra_fixture = r#"
+            //- /main.rs crate:main deps:dep
+            //- /dep.rs crate:dep
+
+            pub struct fmt;
+            pub struct FMT;
+        "#;
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("FMT"));
+
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::fmt (v)
+        dep::FMT (t)
+        dep::FMT (v)
+        "###);
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("FMT").case_sensitive());
+
+        assert_snapshot!(res, @r###"
+        dep::FMT (t)
+        dep::FMT (v)
+        "###);
+    }
+
+    #[test]
+    fn search_limit() {
+        let res = search_dependencies_of(
+            r#"
+        //- /main.rs crate:main deps:dep
+        //- /dep.rs crate:dep
+        pub mod fmt {
+            pub trait Display {
+                fn fmt();
+            }
+        }
+        #[macro_export]
+        macro_rules! Fmt {
+            () => {};
+        }
+        pub struct Fmt;
+
+        pub fn format() {}
+        pub fn no() {}
+    "#,
+            "main",
+            Query::new("").limit(2),
+        );
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        "###);
+    }
+}
diff --git a/crates/ra_hir_def/src/item_scope.rs b/crates/ra_hir_def/src/item_scope.rs
index fc15948ad..beeb98559 100644
--- a/crates/ra_hir_def/src/item_scope.rs
+++ b/crates/ra_hir_def/src/item_scope.rs
@@ -1,18 +1,39 @@
 //! Describes items defined or visible (ie, imported) in a certain scope.
 //! This is shared between modules and blocks.
 
+use std::collections::hash_map::Entry;
+
 use hir_expand::name::Name;
 use once_cell::sync::Lazy;
-use rustc_hash::FxHashMap;
+use ra_db::CrateId;
+use rustc_hash::{FxHashMap, FxHashSet};
+use test_utils::mark;
 
 use crate::{
-    per_ns::PerNs, visibility::Visibility, AdtId, BuiltinType, ImplId, MacroDefId, ModuleDefId,
-    TraitId,
+    db::DefDatabase, per_ns::PerNs, visibility::Visibility, AdtId, BuiltinType, HasModule, ImplId,
+    LocalModuleId, Lookup, MacroDefId, ModuleDefId, TraitId,
 };
 
+#[derive(Copy, Clone)]
+pub(crate) enum ImportType {
+    Glob,
+    Named,
+}
+
+#[derive(Debug, Default)]
+pub struct PerNsGlobImports {
+    types: FxHashSet<(LocalModuleId, Name)>,
+    values: FxHashSet<(LocalModuleId, Name)>,
+    macros: FxHashSet<(LocalModuleId, Name)>,
+}
+
 #[derive(Debug, Default, PartialEq, Eq)]
 pub struct ItemScope {
-    visible: FxHashMap<Name, PerNs>,
+    types: FxHashMap<Name, (ModuleDefId, Visibility)>,
+    values: FxHashMap<Name, (ModuleDefId, Visibility)>,
+    macros: FxHashMap<Name, (MacroDefId, Visibility)>,
+    unresolved: FxHashSet<Name>,
+
     defs: Vec<ModuleDefId>,
     impls: Vec<ImplId>,
     /// Macros visible in current module in legacy textual scope
@@ -50,14 +71,16 @@ pub(crate) enum BuiltinShadowMode {
 /// Other methods will only resolve values, types and module scoped macros only.
 impl ItemScope {
     pub fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a Name, PerNs)> + 'a {
-        //FIXME: shadowing
-        self.visible.iter().map(|(n, def)| (n, *def))
-    }
+        // FIXME: shadowing
+        let keys: FxHashSet<_> = self
+            .types
+            .keys()
+            .chain(self.values.keys())
+            .chain(self.macros.keys())
+            .chain(self.unresolved.iter())
+            .collect();
 
-    pub fn entries_without_primitives<'a>(
-        &'a self,
-    ) -> impl Iterator<Item = (&'a Name, PerNs)> + 'a {
-        self.visible.iter().map(|(n, def)| (n, *def))
+        keys.into_iter().map(move |name| (name, self.get(name)))
     }
 
     pub fn declarations(&self) -> impl Iterator<Item = ModuleDefId> + '_ {
@@ -76,7 +99,7 @@ impl ItemScope {
 
     /// Iterate over all module scoped macros
     pub(crate) fn macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
-        self.visible.iter().filter_map(|(name, def)| def.take_macros().map(|macro_| (name, macro_)))
+        self.entries().filter_map(|(name, def)| def.take_macros().map(|macro_| (name, macro_)))
     }
 
     /// Iterate over all legacy textual scoped macros visible at the end of the module
@@ -86,12 +109,16 @@ impl ItemScope {
 
     /// Get a name from current module scope, legacy macros are not included
     pub(crate) fn get(&self, name: &Name) -> PerNs {
-        self.visible.get(name).copied().unwrap_or_else(PerNs::none)
+        PerNs {
+            types: self.types.get(name).copied(),
+            values: self.values.get(name).copied(),
+            macros: self.macros.get(name).copied(),
+        }
     }
 
     pub(crate) fn name_of(&self, item: ItemInNs) -> Option<(&Name, Visibility)> {
-        for (name, per_ns) in &self.visible {
-            if let Some(vis) = item.match_with(*per_ns) {
+        for (name, per_ns) in self.entries() {
+            if let Some(vis) = item.match_with(per_ns) {
                 return Some((name, vis));
             }
         }
@@ -99,8 +126,8 @@ impl ItemScope {
     }
 
     pub(crate) fn traits<'a>(&'a self) -> impl Iterator<Item = TraitId> + 'a {
-        self.visible.values().filter_map(|def| match def.take_types() {
-            Some(ModuleDefId::TraitId(t)) => Some(t),
+        self.types.values().filter_map(|(def, _)| match def {
+            ModuleDefId::TraitId(t) => Some(*t),
             _ => None,
         })
     }
@@ -123,26 +150,99 @@ impl ItemScope {
 
     pub(crate) fn push_res(&mut self, name: Name, def: PerNs) -> bool {
         let mut changed = false;
-        let existing = self.visible.entry(name).or_default();
 
-        if existing.types.is_none() && def.types.is_some() {
-            existing.types = def.types;
-            changed = true;
+        if let Some(types) = def.types {
+            self.types.entry(name.clone()).or_insert_with(|| {
+                changed = true;
+                types
+            });
         }
-        if existing.values.is_none() && def.values.is_some() {
-            existing.values = def.values;
-            changed = true;
+        if let Some(values) = def.values {
+            self.values.entry(name.clone()).or_insert_with(|| {
+                changed = true;
+                values
+            });
+        }
+        if let Some(macros) = def.macros {
+            self.macros.entry(name.clone()).or_insert_with(|| {
+                changed = true;
+                macros
+            });
+        }
+
+        if def.is_none() {
+            if self.unresolved.insert(name) {
+                changed = true;
+            }
+        }
+
+        changed
+    }
+
+    pub(crate) fn push_res_with_import(
+        &mut self,
+        glob_imports: &mut PerNsGlobImports,
+        lookup: (LocalModuleId, Name),
+        def: PerNs,
+        def_import_type: ImportType,
+    ) -> bool {
+        let mut changed = false;
+
+        macro_rules! check_changed {
+            (
+                $changed:ident,
+                ( $this:ident / $def:ident ) . $field:ident,
+                $glob_imports:ident [ $lookup:ident ],
+                $def_import_type:ident
+            ) => {{
+                let existing = $this.$field.entry($lookup.1.clone());
+                match (existing, $def.$field) {
+                    (Entry::Vacant(entry), Some(_)) => {
+                        match $def_import_type {
+                            ImportType::Glob => {
+                                $glob_imports.$field.insert($lookup.clone());
+                            }
+                            ImportType::Named => {
+                                $glob_imports.$field.remove(&$lookup);
+                            }
+                        }
+
+                        if let Some(fld) = $def.$field {
+                            entry.insert(fld);
+                        }
+                        $changed = true;
+                    }
+                    (Entry::Occupied(mut entry), Some(_))
+                        if $glob_imports.$field.contains(&$lookup)
+                            && matches!($def_import_type, ImportType::Named) =>
+                    {
+                        mark::hit!(import_shadowed);
+                        $glob_imports.$field.remove(&$lookup);
+                        if let Some(fld) = $def.$field {
+                            entry.insert(fld);
+                        }
+                        $changed = true;
+                    }
+                    _ => {}
+                }
+            }};
         }
-        if existing.macros.is_none() && def.macros.is_some() {
-            existing.macros = def.macros;
-            changed = true;
+
+        check_changed!(changed, (self / def).types, glob_imports[lookup], def_import_type);
+        check_changed!(changed, (self / def).values, glob_imports[lookup], def_import_type);
+        check_changed!(changed, (self / def).macros, glob_imports[lookup], def_import_type);
+
+        if def.is_none() {
+            if self.unresolved.insert(lookup.1) {
+                changed = true;
+            }
         }
 
         changed
     }
 
     pub(crate) fn resolutions<'a>(&'a self) -> impl Iterator<Item = (Name, PerNs)> + 'a {
-        self.visible.iter().map(|(name, res)| (name.clone(), *res))
+        self.entries().map(|(name, res)| (name.clone(), res))
     }
 
     pub(crate) fn collect_legacy_macros(&self) -> FxHashMap<Name, MacroDefId> {
@@ -203,4 +303,22 @@ impl ItemInNs {
             ItemInNs::Macros(_) => None,
         }
     }
+
+    /// Returns the crate defining this item (or `None` if `self` is built-in).
+    pub fn krate(&self, db: &dyn DefDatabase) -> Option<CrateId> {
+        Some(match self {
+            ItemInNs::Types(did) | ItemInNs::Values(did) => match did {
+                ModuleDefId::ModuleId(id) => id.krate,
+                ModuleDefId::FunctionId(id) => id.lookup(db).module(db).krate,
+                ModuleDefId::AdtId(id) => id.module(db).krate,
+                ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container.module(db).krate,
+                ModuleDefId::ConstId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::StaticId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::TraitId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::TypeAliasId(id) => id.lookup(db).module(db).krate,
+                ModuleDefId::BuiltinType(_) => return None,
+            },
+            ItemInNs::Macros(id) => return id.krate,
+        })
+    }
 }
diff --git a/crates/ra_hir_def/src/item_tree.rs b/crates/ra_hir_def/src/item_tree.rs
new file mode 100644
index 000000000..da79d8ffd
--- /dev/null
+++ b/crates/ra_hir_def/src/item_tree.rs
@@ -0,0 +1,754 @@
+//! A simplified AST that only contains items.
+
+mod lower;
+#[cfg(test)]
+mod tests;
+
+use std::{
+    any::type_name,
+    fmt::{self, Debug},
+    hash::{Hash, Hasher},
+    marker::PhantomData,
+    ops::{Index, Range},
+    sync::Arc,
+};
+
+use ast::{AstNode, AttrsOwner, NameOwner, StructKind, TypeAscriptionOwner};
+use either::Either;
+use hir_expand::{
+    ast_id_map::FileAstId,
+    hygiene::Hygiene,
+    name::{name, AsName, Name},
+    HirFileId, InFile,
+};
+use ra_arena::{Arena, Idx, RawId};
+use ra_syntax::{ast, match_ast};
+use rustc_hash::FxHashMap;
+use smallvec::SmallVec;
+use test_utils::mark;
+
+use crate::{
+    attr::Attrs,
+    db::DefDatabase,
+    generics::GenericParams,
+    path::{path, AssociatedTypeBinding, GenericArgs, ImportAlias, ModPath, Path, PathKind},
+    type_ref::{Mutability, TypeBound, TypeRef},
+    visibility::RawVisibility,
+};
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub struct RawVisibilityId(u32);
+
+impl RawVisibilityId {
+    pub const PUB: Self = RawVisibilityId(u32::max_value());
+    pub const PRIV: Self = RawVisibilityId(u32::max_value() - 1);
+    pub const PUB_CRATE: Self = RawVisibilityId(u32::max_value() - 2);
+}
+
+impl fmt::Debug for RawVisibilityId {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut f = f.debug_tuple("RawVisibilityId");
+        match *self {
+            Self::PUB => f.field(&"pub"),
+            Self::PRIV => f.field(&"pub(self)"),
+            Self::PUB_CRATE => f.field(&"pub(crate)"),
+            _ => f.field(&self.0),
+        };
+        f.finish()
+    }
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct GenericParamsId(u32);
+
+impl GenericParamsId {
+    pub const EMPTY: Self = GenericParamsId(u32::max_value());
+}
+
+/// The item tree of a source file.
+#[derive(Debug, Eq, PartialEq)]
+pub struct ItemTree {
+    top_level: SmallVec<[ModItem; 1]>,
+    attrs: FxHashMap<AttrOwner, Attrs>,
+    inner_items: FxHashMap<FileAstId<ast::ModuleItem>, SmallVec<[ModItem; 1]>>,
+
+    data: Option<Box<ItemTreeData>>,
+}
+
+impl ItemTree {
+    pub fn item_tree_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<ItemTree> {
+        let _p = ra_prof::profile("item_tree_query").detail(|| format!("{:?}", file_id));
+        let syntax = if let Some(node) = db.parse_or_expand(file_id) {
+            node
+        } else {
+            return Arc::new(Self::empty());
+        };
+
+        let hygiene = Hygiene::new(db.upcast(), file_id);
+        let ctx = lower::Ctx::new(db, hygiene.clone(), file_id);
+        let mut top_attrs = None;
+        let mut item_tree = match_ast! {
+            match syntax {
+                ast::SourceFile(file) => {
+                    top_attrs = Some(Attrs::new(&file, &hygiene));
+                    ctx.lower_module_items(&file)
+                },
+                ast::MacroItems(items) => {
+                    ctx.lower_module_items(&items)
+                },
+                // Macros can expand to expressions. We return an empty item tree in this case, but
+                // still need to collect inner items.
+                ast::Expr(e) => {
+                    ctx.lower_inner_items(e.syntax())
+                },
+                _ => {
+                    panic!("cannot create item tree from {:?}", syntax);
+                },
+            }
+        };
+
+        if let Some(attrs) = top_attrs {
+            item_tree.attrs.insert(AttrOwner::TopLevel, attrs);
+        }
+        item_tree.shrink_to_fit();
+        Arc::new(item_tree)
+    }
+
+    fn empty() -> Self {
+        Self {
+            top_level: Default::default(),
+            attrs: Default::default(),
+            inner_items: Default::default(),
+            data: Default::default(),
+        }
+    }
+
+    fn shrink_to_fit(&mut self) {
+        if let Some(data) = &mut self.data {
+            let ItemTreeData {
+                imports,
+                extern_crates,
+                functions,
+                structs,
+                fields,
+                unions,
+                enums,
+                variants,
+                consts,
+                statics,
+                traits,
+                impls,
+                type_aliases,
+                mods,
+                macro_calls,
+                exprs,
+                vis,
+                generics,
+            } = &mut **data;
+
+            imports.shrink_to_fit();
+            extern_crates.shrink_to_fit();
+            functions.shrink_to_fit();
+            structs.shrink_to_fit();
+            fields.shrink_to_fit();
+            unions.shrink_to_fit();
+            enums.shrink_to_fit();
+            variants.shrink_to_fit();
+            consts.shrink_to_fit();
+            statics.shrink_to_fit();
+            traits.shrink_to_fit();
+            impls.shrink_to_fit();
+            type_aliases.shrink_to_fit();
+            mods.shrink_to_fit();
+            macro_calls.shrink_to_fit();
+            exprs.shrink_to_fit();
+
+            vis.arena.shrink_to_fit();
+            generics.arena.shrink_to_fit();
+        }
+    }
+
+    /// Returns an iterator over all items located at the top level of the `HirFileId` this
+    /// `ItemTree` was created from.
+    pub fn top_level_items(&self) -> &[ModItem] {
+        &self.top_level
+    }
+
+    /// Returns the inner attributes of the source file.
+    pub fn top_level_attrs(&self) -> &Attrs {
+        self.attrs.get(&AttrOwner::TopLevel).unwrap_or(&Attrs::EMPTY)
+    }
+
+    pub fn attrs(&self, of: AttrOwner) -> &Attrs {
+        self.attrs.get(&of).unwrap_or(&Attrs::EMPTY)
+    }
+
+    /// Returns the lowered inner items that `ast` corresponds to.
+    ///
+    /// Most AST items are lowered to a single `ModItem`, but some (eg. `use` items) may be lowered
+    /// to multiple items in the `ItemTree`.
+    pub fn inner_items(&self, ast: FileAstId<ast::ModuleItem>) -> &[ModItem] {
+        &self.inner_items[&ast]
+    }
+
+    pub fn all_inner_items(&self) -> impl Iterator<Item = ModItem> + '_ {
+        self.inner_items.values().flatten().copied()
+    }
+
+    pub fn source<S: ItemTreeNode>(&self, db: &dyn DefDatabase, of: ItemTreeId<S>) -> S::Source {
+        // This unwrap cannot fail, since it has either succeeded above, or resulted in an empty
+        // ItemTree (in which case there is no valid `FileItemTreeId` to call this method with).
+        let root =
+            db.parse_or_expand(of.file_id).expect("parse_or_expand failed on constructed ItemTree");
+
+        let id = self[of.value].ast_id();
+        let map = db.ast_id_map(of.file_id);
+        let ptr = map.get(id);
+        ptr.to_node(&root)
+    }
+
+    fn data(&self) -> &ItemTreeData {
+        self.data.as_ref().expect("attempted to access data of empty ItemTree")
+    }
+
+    fn data_mut(&mut self) -> &mut ItemTreeData {
+        self.data.get_or_insert_with(Box::default)
+    }
+}
+
+#[derive(Default, Debug, Eq, PartialEq)]
+struct ItemVisibilities {
+    arena: Arena<RawVisibility>,
+}
+
+impl ItemVisibilities {
+    fn alloc(&mut self, vis: RawVisibility) -> RawVisibilityId {
+        match &vis {
+            RawVisibility::Public => RawVisibilityId::PUB,
+            RawVisibility::Module(path) if path.segments.is_empty() => match &path.kind {
+                PathKind::Super(0) => RawVisibilityId::PRIV,
+                PathKind::Crate => RawVisibilityId::PUB_CRATE,
+                _ => RawVisibilityId(self.arena.alloc(vis).into_raw().into()),
+            },
+            _ => RawVisibilityId(self.arena.alloc(vis).into_raw().into()),
+        }
+    }
+}
+
+static VIS_PUB: RawVisibility = RawVisibility::Public;
+static VIS_PRIV: RawVisibility =
+    RawVisibility::Module(ModPath { kind: PathKind::Super(0), segments: Vec::new() });
+static VIS_PUB_CRATE: RawVisibility =
+    RawVisibility::Module(ModPath { kind: PathKind::Crate, segments: Vec::new() });
+
+#[derive(Default, Debug, Eq, PartialEq)]
+struct GenericParamsStorage {
+    arena: Arena<GenericParams>,
+}
+
+impl GenericParamsStorage {
+    fn alloc(&mut self, params: GenericParams) -> GenericParamsId {
+        if params.types.is_empty() && params.where_predicates.is_empty() {
+            return GenericParamsId::EMPTY;
+        }
+
+        GenericParamsId(self.arena.alloc(params).into_raw().into())
+    }
+}
+
+static EMPTY_GENERICS: GenericParams =
+    GenericParams { types: Arena::new(), where_predicates: Vec::new() };
+
+#[derive(Default, Debug, Eq, PartialEq)]
+struct ItemTreeData {
+    imports: Arena<Import>,
+    extern_crates: Arena<ExternCrate>,
+    functions: Arena<Function>,
+    structs: Arena<Struct>,
+    fields: Arena<Field>,
+    unions: Arena<Union>,
+    enums: Arena<Enum>,
+    variants: Arena<Variant>,
+    consts: Arena<Const>,
+    statics: Arena<Static>,
+    traits: Arena<Trait>,
+    impls: Arena<Impl>,
+    type_aliases: Arena<TypeAlias>,
+    mods: Arena<Mod>,
+    macro_calls: Arena<MacroCall>,
+    exprs: Arena<Expr>,
+
+    vis: ItemVisibilities,
+    generics: GenericParamsStorage,
+}
+
+#[derive(Debug, Eq, PartialEq, Hash)]
+pub enum AttrOwner {
+    /// Attributes on an item.
+    ModItem(ModItem),
+    /// Inner attributes of the source file.
+    TopLevel,
+
+    Variant(Idx<Variant>),
+    Field(Idx<Field>),
+    // FIXME: Store variant and field attrs, and stop reparsing them in `attrs_query`.
+}
+
+macro_rules! from_attrs {
+    ( $( $var:ident($t:ty) ),+ ) => {
+        $(
+            impl From<$t> for AttrOwner {
+                fn from(t: $t) -> AttrOwner {
+                    AttrOwner::$var(t)
+                }
+            }
+        )+
+    };
+}
+
+from_attrs!(ModItem(ModItem), Variant(Idx<Variant>), Field(Idx<Field>));
+
+/// Trait implemented by all item nodes in the item tree.
+pub trait ItemTreeNode: Clone {
+    type Source: AstNode + Into<ast::ModuleItem>;
+
+    fn ast_id(&self) -> FileAstId<Self::Source>;
+
+    /// Looks up an instance of `Self` in an item tree.
+    fn lookup(tree: &ItemTree, index: Idx<Self>) -> &Self;
+
+    /// Downcasts a `ModItem` to a `FileItemTreeId` specific to this type.
+    fn id_from_mod_item(mod_item: ModItem) -> Option<FileItemTreeId<Self>>;
+
+    /// Upcasts a `FileItemTreeId` to a generic `ModItem`.
+    fn id_to_mod_item(id: FileItemTreeId<Self>) -> ModItem;
+}
+
+pub struct FileItemTreeId<N: ItemTreeNode> {
+    index: Idx<N>,
+    _p: PhantomData<N>,
+}
+
+impl<N: ItemTreeNode> Clone for FileItemTreeId<N> {
+    fn clone(&self) -> Self {
+        Self { index: self.index, _p: PhantomData }
+    }
+}
+impl<N: ItemTreeNode> Copy for FileItemTreeId<N> {}
+
+impl<N: ItemTreeNode> PartialEq for FileItemTreeId<N> {
+    fn eq(&self, other: &FileItemTreeId<N>) -> bool {
+        self.index == other.index
+    }
+}
+impl<N: ItemTreeNode> Eq for FileItemTreeId<N> {}
+
+impl<N: ItemTreeNode> Hash for FileItemTreeId<N> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.index.hash(state)
+    }
+}
+
+impl<N: ItemTreeNode> fmt::Debug for FileItemTreeId<N> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.index.fmt(f)
+    }
+}
+
+pub type ItemTreeId<N> = InFile<FileItemTreeId<N>>;
+
+macro_rules! mod_items {
+    ( $( $typ:ident in $fld:ident -> $ast:ty ),+ $(,)? ) => {
+        #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+        pub enum ModItem {
+            $(
+                $typ(FileItemTreeId<$typ>),
+            )+
+        }
+
+        $(
+            impl From<FileItemTreeId<$typ>> for ModItem {
+                fn from(id: FileItemTreeId<$typ>) -> ModItem {
+                    ModItem::$typ(id)
+                }
+            }
+        )+
+
+        $(
+            impl ItemTreeNode for $typ {
+                type Source = $ast;
+
+                fn ast_id(&self) -> FileAstId<Self::Source> {
+                    self.ast_id
+                }
+
+                fn lookup(tree: &ItemTree, index: Idx<Self>) -> &Self {
+                    &tree.data().$fld[index]
+                }
+
+                fn id_from_mod_item(mod_item: ModItem) -> Option<FileItemTreeId<Self>> {
+                    if let ModItem::$typ(id) = mod_item {
+                        Some(id)
+                    } else {
+                        None
+                    }
+                }
+
+                fn id_to_mod_item(id: FileItemTreeId<Self>) -> ModItem {
+                    ModItem::$typ(id)
+                }
+            }
+
+            impl Index<Idx<$typ>> for ItemTree {
+                type Output = $typ;
+
+                fn index(&self, index: Idx<$typ>) -> &Self::Output {
+                    &self.data().$fld[index]
+                }
+            }
+        )+
+    };
+}
+
+mod_items! {
+    Import in imports -> ast::UseItem,
+    ExternCrate in extern_crates -> ast::ExternCrateItem,
+    Function in functions -> ast::FnDef,
+    Struct in structs -> ast::StructDef,
+    Union in unions -> ast::UnionDef,
+    Enum in enums -> ast::EnumDef,
+    Const in consts -> ast::ConstDef,
+    Static in statics -> ast::StaticDef,
+    Trait in traits -> ast::TraitDef,
+    Impl in impls -> ast::ImplDef,
+    TypeAlias in type_aliases -> ast::TypeAliasDef,
+    Mod in mods -> ast::Module,
+    MacroCall in macro_calls -> ast::MacroCall,
+}
+
+macro_rules! impl_index {
+    ( $($fld:ident: $t:ty),+ $(,)? ) => {
+        $(
+            impl Index<Idx<$t>> for ItemTree {
+                type Output = $t;
+
+                fn index(&self, index: Idx<$t>) -> &Self::Output {
+                    &self.data().$fld[index]
+                }
+            }
+        )+
+    };
+}
+
+impl_index!(fields: Field, variants: Variant, exprs: Expr);
+
+impl Index<RawVisibilityId> for ItemTree {
+    type Output = RawVisibility;
+    fn index(&self, index: RawVisibilityId) -> &Self::Output {
+        match index {
+            RawVisibilityId::PRIV => &VIS_PRIV,
+            RawVisibilityId::PUB => &VIS_PUB,
+            RawVisibilityId::PUB_CRATE => &VIS_PUB_CRATE,
+            _ => &self.data().vis.arena[Idx::from_raw(index.0.into())],
+        }
+    }
+}
+
+impl Index<GenericParamsId> for ItemTree {
+    type Output = GenericParams;
+
+    fn index(&self, index: GenericParamsId) -> &Self::Output {
+        match index {
+            GenericParamsId::EMPTY => &EMPTY_GENERICS,
+            _ => &self.data().generics.arena[Idx::from_raw(index.0.into())],
+        }
+    }
+}
+
+impl<N: ItemTreeNode> Index<FileItemTreeId<N>> for ItemTree {
+    type Output = N;
+    fn index(&self, id: FileItemTreeId<N>) -> &N {
+        N::lookup(self, id.index)
+    }
+}
+
+/// A desugared `use` import.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Import {
+    pub path: ModPath,
+    pub alias: Option<ImportAlias>,
+    pub visibility: RawVisibilityId,
+    pub is_glob: bool,
+    pub is_prelude: bool,
+    /// AST ID of the `use` or `extern crate` item this import was derived from. Note that many
+    /// `Import`s can map to the same `use` item.
+    pub ast_id: FileAstId<ast::UseItem>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ExternCrate {
+    pub path: ModPath,
+    pub alias: Option<ImportAlias>,
+    pub visibility: RawVisibilityId,
+    /// Whether this is a `#[macro_use] extern crate ...`.
+    pub is_macro_use: bool,
+    pub ast_id: FileAstId<ast::ExternCrateItem>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Function {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub generic_params: GenericParamsId,
+    pub has_self_param: bool,
+    pub is_unsafe: bool,
+    pub params: Box<[TypeRef]>,
+    pub is_varargs: bool,
+    pub ret_type: TypeRef,
+    pub ast_id: FileAstId<ast::FnDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Struct {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub generic_params: GenericParamsId,
+    pub fields: Fields,
+    pub ast_id: FileAstId<ast::StructDef>,
+    pub kind: StructDefKind,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum StructDefKind {
+    /// `struct S { ... }` - type namespace only.
+    Record,
+    /// `struct S(...);`
+    Tuple,
+    /// `struct S;`
+    Unit,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Union {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub generic_params: GenericParamsId,
+    pub fields: Fields,
+    pub ast_id: FileAstId<ast::UnionDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Enum {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub generic_params: GenericParamsId,
+    pub variants: IdRange<Variant>,
+    pub ast_id: FileAstId<ast::EnumDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Const {
+    /// const _: () = ();
+    pub name: Option<Name>,
+    pub visibility: RawVisibilityId,
+    pub type_ref: TypeRef,
+    pub ast_id: FileAstId<ast::ConstDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Static {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub mutable: bool,
+    pub type_ref: TypeRef,
+    pub ast_id: FileAstId<ast::StaticDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Trait {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub generic_params: GenericParamsId,
+    pub auto: bool,
+    pub items: Box<[AssocItem]>,
+    pub ast_id: FileAstId<ast::TraitDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Impl {
+    pub generic_params: GenericParamsId,
+    pub target_trait: Option<TypeRef>,
+    pub target_type: TypeRef,
+    pub is_negative: bool,
+    pub items: Box<[AssocItem]>,
+    pub ast_id: FileAstId<ast::ImplDef>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TypeAlias {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    /// Bounds on the type alias itself. Only valid in trait declarations, eg. `type Assoc: Copy;`.
+    pub bounds: Box<[TypeBound]>,
+    pub generic_params: GenericParamsId,
+    pub type_ref: Option<TypeRef>,
+    pub ast_id: FileAstId<ast::TypeAliasDef>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Mod {
+    pub name: Name,
+    pub visibility: RawVisibilityId,
+    pub kind: ModKind,
+    pub ast_id: FileAstId<ast::Module>,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum ModKind {
+    /// `mod m { ... }`
+    Inline { items: Box<[ModItem]> },
+
+    /// `mod m;`
+    Outline {},
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct MacroCall {
+    /// For `macro_rules!` declarations, this is the name of the declared macro.
+    pub name: Option<Name>,
+    /// Path to the called macro.
+    pub path: ModPath,
+    /// Has `#[macro_export]`.
+    pub is_export: bool,
+    /// Has `#[macro_export(local_inner_macros)]`.
+    pub is_local_inner: bool,
+    /// Has `#[rustc_builtin_macro]`.
+    pub is_builtin: bool,
+    pub ast_id: FileAstId<ast::MacroCall>,
+}
+
+// NB: There's no `FileAstId` for `Expr`. The only case where this would be useful is for array
+// lengths, but we don't do much with them yet.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct Expr;
+
+macro_rules! impl_froms {
+    ($e:ident { $($v:ident ($t:ty)),* $(,)? }) => {
+        $(
+            impl From<$t> for $e {
+                fn from(it: $t) -> $e {
+                    $e::$v(it)
+                }
+            }
+        )*
+    }
+}
+
+impl ModItem {
+    pub fn as_assoc_item(&self) -> Option<AssocItem> {
+        match self {
+            ModItem::Import(_)
+            | ModItem::ExternCrate(_)
+            | ModItem::Struct(_)
+            | ModItem::Union(_)
+            | ModItem::Enum(_)
+            | ModItem::Static(_)
+            | ModItem::Trait(_)
+            | ModItem::Impl(_)
+            | ModItem::Mod(_) => None,
+            ModItem::MacroCall(call) => Some(AssocItem::MacroCall(*call)),
+            ModItem::Const(konst) => Some(AssocItem::Const(*konst)),
+            ModItem::TypeAlias(alias) => Some(AssocItem::TypeAlias(*alias)),
+            ModItem::Function(func) => Some(AssocItem::Function(*func)),
+        }
+    }
+
+    pub fn downcast<N: ItemTreeNode>(self) -> Option<FileItemTreeId<N>> {
+        N::id_from_mod_item(self)
+    }
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub enum AssocItem {
+    Function(FileItemTreeId<Function>),
+    TypeAlias(FileItemTreeId<TypeAlias>),
+    Const(FileItemTreeId<Const>),
+    MacroCall(FileItemTreeId<MacroCall>),
+}
+
+impl_froms!(AssocItem {
+    Function(FileItemTreeId<Function>),
+    TypeAlias(FileItemTreeId<TypeAlias>),
+    Const(FileItemTreeId<Const>),
+    MacroCall(FileItemTreeId<MacroCall>),
+});
+
+impl From<AssocItem> for ModItem {
+    fn from(item: AssocItem) -> Self {
+        match item {
+            AssocItem::Function(it) => it.into(),
+            AssocItem::TypeAlias(it) => it.into(),
+            AssocItem::Const(it) => it.into(),
+            AssocItem::MacroCall(it) => it.into(),
+        }
+    }
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Variant {
+    pub name: Name,
+    pub fields: Fields,
+}
+
+pub struct IdRange<T> {
+    range: Range<u32>,
+    _p: PhantomData<T>,
+}
+
+impl<T> IdRange<T> {
+    fn new(range: Range<Idx<T>>) -> Self {
+        Self { range: range.start.into_raw().into()..range.end.into_raw().into(), _p: PhantomData }
+    }
+}
+
+impl<T> Iterator for IdRange<T> {
+    type Item = Idx<T>;
+    fn next(&mut self) -> Option<Self::Item> {
+        self.range.next().map(|raw| Idx::from_raw(raw.into()))
+    }
+}
+
+impl<T> fmt::Debug for IdRange<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple(&format!("IdRange::<{}>", type_name::<T>())).field(&self.range).finish()
+    }
+}
+
+impl<T> Clone for IdRange<T> {
+    fn clone(&self) -> Self {
+        Self { range: self.range.clone(), _p: PhantomData }
+    }
+}
+
+impl<T> PartialEq for IdRange<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.range == other.range
+    }
+}
+
+impl<T> Eq for IdRange<T> {}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Fields {
+    Record(IdRange<Field>),
+    Tuple(IdRange<Field>),
+    Unit,
+}
+
+/// A single field of an enum variant or struct
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Field {
+    pub name: Name,
+    pub type_ref: TypeRef,
+    pub visibility: RawVisibilityId,
+}
diff --git a/crates/ra_hir_def/src/item_tree/lower.rs b/crates/ra_hir_def/src/item_tree/lower.rs
new file mode 100644
index 000000000..f79b8fca3
--- /dev/null
+++ b/crates/ra_hir_def/src/item_tree/lower.rs
@@ -0,0 +1,708 @@
+//! AST -> `ItemTree` lowering code.
+
+use super::*;
+use crate::{
+    attr::Attrs,
+    generics::{GenericParams, TypeParamData, TypeParamProvenance},
+};
+use hir_expand::{ast_id_map::AstIdMap, hygiene::Hygiene, HirFileId};
+use ra_arena::map::ArenaMap;
+use ra_syntax::{
+    ast::{self, ModuleItemOwner},
+    SyntaxNode,
+};
+use smallvec::SmallVec;
+use std::{collections::hash_map::Entry, mem, sync::Arc};
+
+fn id<N: ItemTreeNode>(index: Idx<N>) -> FileItemTreeId<N> {
+    FileItemTreeId { index, _p: PhantomData }
+}
+
+struct ModItems(SmallVec<[ModItem; 1]>);
+
+impl<T> From<T> for ModItems
+where
+    T: Into<ModItem>,
+{
+    fn from(t: T) -> Self {
+        ModItems(SmallVec::from_buf([t.into(); 1]))
+    }
+}
+
+pub(super) struct Ctx {
+    tree: ItemTree,
+    hygiene: Hygiene,
+    file: HirFileId,
+    source_ast_id_map: Arc<AstIdMap>,
+    body_ctx: crate::body::LowerCtx,
+    inner_items: Vec<ModItem>,
+    forced_visibility: Option<RawVisibilityId>,
+}
+
+impl Ctx {
+    pub(super) fn new(db: &dyn DefDatabase, hygiene: Hygiene, file: HirFileId) -> Self {
+        Self {
+            tree: ItemTree::empty(),
+            hygiene,
+            file,
+            source_ast_id_map: db.ast_id_map(file),
+            body_ctx: crate::body::LowerCtx::new(db, file),
+            inner_items: Vec::new(),
+            forced_visibility: None,
+        }
+    }
+
+    pub(super) fn lower_module_items(mut self, item_owner: &dyn ModuleItemOwner) -> ItemTree {
+        self.tree.top_level = item_owner
+            .items()
+            .flat_map(|item| self.lower_mod_item(&item, false))
+            .flat_map(|items| items.0)
+            .collect();
+        self.tree
+    }
+
+    pub(super) fn lower_inner_items(mut self, within: &SyntaxNode) -> ItemTree {
+        self.collect_inner_items(within);
+        self.tree
+    }
+
+    fn data(&mut self) -> &mut ItemTreeData {
+        self.tree.data_mut()
+    }
+
+    fn lower_mod_item(&mut self, item: &ast::ModuleItem, inner: bool) -> Option<ModItems> {
+        assert!(inner || self.inner_items.is_empty());
+
+        // Collect inner items for 1-to-1-lowered items.
+        match item {
+            ast::ModuleItem::StructDef(_)
+            | ast::ModuleItem::UnionDef(_)
+            | ast::ModuleItem::EnumDef(_)
+            | ast::ModuleItem::FnDef(_)
+            | ast::ModuleItem::TypeAliasDef(_)
+            | ast::ModuleItem::ConstDef(_)
+            | ast::ModuleItem::StaticDef(_)
+            | ast::ModuleItem::MacroCall(_) => {
+                // Skip this if we're already collecting inner items. We'll descend into all nodes
+                // already.
+                if !inner {
+                    self.collect_inner_items(item.syntax());
+                }
+            }
+
+            // These are handled in their respective `lower_X` method (since we can't just blindly
+            // walk them).
+            ast::ModuleItem::TraitDef(_)
+            | ast::ModuleItem::ImplDef(_)
+            | ast::ModuleItem::ExternBlock(_) => {}
+
+            // These don't have inner items.
+            ast::ModuleItem::Module(_)
+            | ast::ModuleItem::ExternCrateItem(_)
+            | ast::ModuleItem::UseItem(_) => {}
+        };
+
+        let attrs = Attrs::new(item, &self.hygiene);
+        let items = match item {
+            ast::ModuleItem::StructDef(ast) => self.lower_struct(ast).map(Into::into),
+            ast::ModuleItem::UnionDef(ast) => self.lower_union(ast).map(Into::into),
+            ast::ModuleItem::EnumDef(ast) => self.lower_enum(ast).map(Into::into),
+            ast::ModuleItem::FnDef(ast) => self.lower_function(ast).map(Into::into),
+            ast::ModuleItem::TypeAliasDef(ast) => self.lower_type_alias(ast).map(Into::into),
+            ast::ModuleItem::StaticDef(ast) => self.lower_static(ast).map(Into::into),
+            ast::ModuleItem::ConstDef(ast) => Some(self.lower_const(ast).into()),
+            ast::ModuleItem::Module(ast) => self.lower_module(ast).map(Into::into),
+            ast::ModuleItem::TraitDef(ast) => self.lower_trait(ast).map(Into::into),
+            ast::ModuleItem::ImplDef(ast) => self.lower_impl(ast).map(Into::into),
+            ast::ModuleItem::UseItem(ast) => Some(ModItems(
+                self.lower_use(ast).into_iter().map(Into::into).collect::<SmallVec<_>>(),
+            )),
+            ast::ModuleItem::ExternCrateItem(ast) => self.lower_extern_crate(ast).map(Into::into),
+            ast::ModuleItem::MacroCall(ast) => self.lower_macro_call(ast).map(Into::into),
+            ast::ModuleItem::ExternBlock(ast) => {
+                Some(ModItems(self.lower_extern_block(ast).into_iter().collect::<SmallVec<_>>()))
+            }
+        };
+
+        if !attrs.is_empty() {
+            for item in items.iter().flat_map(|items| &items.0) {
+                self.add_attrs((*item).into(), attrs.clone());
+            }
+        }
+
+        items
+    }
+
+    fn add_attrs(&mut self, item: AttrOwner, attrs: Attrs) {
+        match self.tree.attrs.entry(item) {
+            Entry::Occupied(mut entry) => {
+                *entry.get_mut() = entry.get().merge(attrs);
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(attrs);
+            }
+        }
+    }
+
+    fn collect_inner_items(&mut self, container: &SyntaxNode) {
+        let forced_vis = self.forced_visibility.take();
+        let mut inner_items = mem::take(&mut self.tree.inner_items);
+        inner_items.extend(
+            container.descendants().skip(1).filter_map(ast::ModuleItem::cast).filter_map(|item| {
+                let ast_id = self.source_ast_id_map.ast_id(&item);
+                Some((ast_id, self.lower_mod_item(&item, true)?.0))
+            }),
+        );
+        self.tree.inner_items = inner_items;
+        self.forced_visibility = forced_vis;
+    }
+
+    fn lower_assoc_item(&mut self, item: &ast::ModuleItem) -> Option<AssocItem> {
+        match item {
+            ast::ModuleItem::FnDef(ast) => self.lower_function(ast).map(Into::into),
+            ast::ModuleItem::TypeAliasDef(ast) => self.lower_type_alias(ast).map(Into::into),
+            ast::ModuleItem::ConstDef(ast) => Some(self.lower_const(ast).into()),
+            ast::ModuleItem::MacroCall(ast) => self.lower_macro_call(ast).map(Into::into),
+            _ => None,
+        }
+    }
+
+    fn lower_struct(&mut self, strukt: &ast::StructDef) -> Option<FileItemTreeId<Struct>> {
+        let visibility = self.lower_visibility(strukt);
+        let name = strukt.name()?.as_name();
+        let generic_params = self.lower_generic_params(GenericsOwner::Struct, strukt);
+        let fields = self.lower_fields(&strukt.kind());
+        let ast_id = self.source_ast_id_map.ast_id(strukt);
+        let kind = match strukt.kind() {
+            ast::StructKind::Record(_) => StructDefKind::Record,
+            ast::StructKind::Tuple(_) => StructDefKind::Tuple,
+            ast::StructKind::Unit => StructDefKind::Unit,
+        };
+        let res = Struct { name, visibility, generic_params, fields, ast_id, kind };
+        Some(id(self.data().structs.alloc(res)))
+    }
+
+    fn lower_fields(&mut self, strukt_kind: &ast::StructKind) -> Fields {
+        match strukt_kind {
+            ast::StructKind::Record(it) => {
+                let range = self.lower_record_fields(it);
+                Fields::Record(range)
+            }
+            ast::StructKind::Tuple(it) => {
+                let range = self.lower_tuple_fields(it);
+                Fields::Tuple(range)
+            }
+            ast::StructKind::Unit => Fields::Unit,
+        }
+    }
+
+    fn lower_record_fields(&mut self, fields: &ast::RecordFieldDefList) -> IdRange<Field> {
+        let start = self.next_field_idx();
+        for field in fields.fields() {
+            if let Some(data) = self.lower_record_field(&field) {
+                let idx = self.data().fields.alloc(data);
+                self.add_attrs(idx.into(), Attrs::new(&field, &self.hygiene));
+            }
+        }
+        let end = self.next_field_idx();
+        IdRange::new(start..end)
+    }
+
+    fn lower_record_field(&mut self, field: &ast::RecordFieldDef) -> Option<Field> {
+        let name = field.name()?.as_name();
+        let visibility = self.lower_visibility(field);
+        let type_ref = self.lower_type_ref_opt(field.ascribed_type());
+        let res = Field { name, type_ref, visibility };
+        Some(res)
+    }
+
+    fn lower_tuple_fields(&mut self, fields: &ast::TupleFieldDefList) -> IdRange<Field> {
+        let start = self.next_field_idx();
+        for (i, field) in fields.fields().enumerate() {
+            let data = self.lower_tuple_field(i, &field);
+            let idx = self.data().fields.alloc(data);
+            self.add_attrs(idx.into(), Attrs::new(&field, &self.hygiene));
+        }
+        let end = self.next_field_idx();
+        IdRange::new(start..end)
+    }
+
+    fn lower_tuple_field(&mut self, idx: usize, field: &ast::TupleFieldDef) -> Field {
+        let name = Name::new_tuple_field(idx);
+        let visibility = self.lower_visibility(field);
+        let type_ref = self.lower_type_ref_opt(field.type_ref());
+        let res = Field { name, type_ref, visibility };
+        res
+    }
+
+    fn lower_union(&mut self, union: &ast::UnionDef) -> Option<FileItemTreeId<Union>> {
+        let visibility = self.lower_visibility(union);
+        let name = union.name()?.as_name();
+        let generic_params = self.lower_generic_params(GenericsOwner::Union, union);
+        let fields = match union.record_field_def_list() {
+            Some(record_field_def_list) => {
+                self.lower_fields(&StructKind::Record(record_field_def_list))
+            }
+            None => Fields::Record(IdRange::new(self.next_field_idx()..self.next_field_idx())),
+        };
+        let ast_id = self.source_ast_id_map.ast_id(union);
+        let res = Union { name, visibility, generic_params, fields, ast_id };
+        Some(id(self.data().unions.alloc(res)))
+    }
+
+    fn lower_enum(&mut self, enum_: &ast::EnumDef) -> Option<FileItemTreeId<Enum>> {
+        let visibility = self.lower_visibility(enum_);
+        let name = enum_.name()?.as_name();
+        let generic_params = self.lower_generic_params(GenericsOwner::Enum, enum_);
+        let variants = match &enum_.variant_list() {
+            Some(variant_list) => self.lower_variants(variant_list),
+            None => IdRange::new(self.next_variant_idx()..self.next_variant_idx()),
+        };
+        let ast_id = self.source_ast_id_map.ast_id(enum_);
+        let res = Enum { name, visibility, generic_params, variants, ast_id };
+        Some(id(self.data().enums.alloc(res)))
+    }
+
+    fn lower_variants(&mut self, variants: &ast::EnumVariantList) -> IdRange<Variant> {
+        let start = self.next_variant_idx();
+        for variant in variants.variants() {
+            if let Some(data) = self.lower_variant(&variant) {
+                let idx = self.data().variants.alloc(data);
+                self.add_attrs(idx.into(), Attrs::new(&variant, &self.hygiene));
+            }
+        }
+        let end = self.next_variant_idx();
+        IdRange::new(start..end)
+    }
+
+    fn lower_variant(&mut self, variant: &ast::EnumVariant) -> Option<Variant> {
+        let name = variant.name()?.as_name();
+        let fields = self.lower_fields(&variant.kind());
+        let res = Variant { name, fields };
+        Some(res)
+    }
+
+    fn lower_function(&mut self, func: &ast::FnDef) -> Option<FileItemTreeId<Function>> {
+        let visibility = self.lower_visibility(func);
+        let name = func.name()?.as_name();
+
+        let mut params = Vec::new();
+        let mut has_self_param = false;
+        if let Some(param_list) = func.param_list() {
+            if let Some(self_param) = param_list.self_param() {
+                let self_type = match self_param.ascribed_type() {
+                    Some(type_ref) => TypeRef::from_ast(&self.body_ctx, type_ref),
+                    None => {
+                        let self_type = TypeRef::Path(name![Self].into());
+                        match self_param.kind() {
+                            ast::SelfParamKind::Owned => self_type,
+                            ast::SelfParamKind::Ref => {
+                                TypeRef::Reference(Box::new(self_type), Mutability::Shared)
+                            }
+                            ast::SelfParamKind::MutRef => {
+                                TypeRef::Reference(Box::new(self_type), Mutability::Mut)
+                            }
+                        }
+                    }
+                };
+                params.push(self_type);
+                has_self_param = true;
+            }
+            for param in param_list.params() {
+                let type_ref = TypeRef::from_ast_opt(&self.body_ctx, param.ascribed_type());
+                params.push(type_ref);
+            }
+        }
+
+        let mut is_varargs = false;
+        if let Some(params) = func.param_list() {
+            if let Some(last) = params.params().last() {
+                is_varargs = last.dotdotdot_token().is_some();
+            }
+        }
+
+        let ret_type = match func.ret_type().and_then(|rt| rt.type_ref()) {
+            Some(type_ref) => TypeRef::from_ast(&self.body_ctx, type_ref),
+            _ => TypeRef::unit(),
+        };
+
+        let ret_type = if func.async_token().is_some() {
+            let future_impl = desugar_future_path(ret_type);
+            let ty_bound = TypeBound::Path(future_impl);
+            TypeRef::ImplTrait(vec![ty_bound])
+        } else {
+            ret_type
+        };
+
+        let ast_id = self.source_ast_id_map.ast_id(func);
+        let mut res = Function {
+            name,
+            visibility,
+            generic_params: GenericParamsId::EMPTY,
+            has_self_param,
+            is_unsafe: func.unsafe_token().is_some(),
+            params: params.into_boxed_slice(),
+            is_varargs,
+            ret_type,
+            ast_id,
+        };
+        res.generic_params = self.lower_generic_params(GenericsOwner::Function(&res), func);
+
+        Some(id(self.data().functions.alloc(res)))
+    }
+
+    fn lower_type_alias(
+        &mut self,
+        type_alias: &ast::TypeAliasDef,
+    ) -> Option<FileItemTreeId<TypeAlias>> {
+        let name = type_alias.name()?.as_name();
+        let type_ref = type_alias.type_ref().map(|it| self.lower_type_ref(&it));
+        let visibility = self.lower_visibility(type_alias);
+        let bounds = self.lower_type_bounds(type_alias);
+        let generic_params = self.lower_generic_params(GenericsOwner::TypeAlias, type_alias);
+        let ast_id = self.source_ast_id_map.ast_id(type_alias);
+        let res = TypeAlias {
+            name,
+            visibility,
+            bounds: bounds.into_boxed_slice(),
+            generic_params,
+            type_ref,
+            ast_id,
+        };
+        Some(id(self.data().type_aliases.alloc(res)))
+    }
+
+    fn lower_static(&mut self, static_: &ast::StaticDef) -> Option<FileItemTreeId<Static>> {
+        let name = static_.name()?.as_name();
+        let type_ref = self.lower_type_ref_opt(static_.ascribed_type());
+        let visibility = self.lower_visibility(static_);
+        let mutable = static_.mut_token().is_some();
+        let ast_id = self.source_ast_id_map.ast_id(static_);
+        let res = Static { name, visibility, mutable, type_ref, ast_id };
+        Some(id(self.data().statics.alloc(res)))
+    }
+
+    fn lower_const(&mut self, konst: &ast::ConstDef) -> FileItemTreeId<Const> {
+        let name = konst.name().map(|it| it.as_name());
+        let type_ref = self.lower_type_ref_opt(konst.ascribed_type());
+        let visibility = self.lower_visibility(konst);
+        let ast_id = self.source_ast_id_map.ast_id(konst);
+        let res = Const { name, visibility, type_ref, ast_id };
+        id(self.data().consts.alloc(res))
+    }
+
+    fn lower_module(&mut self, module: &ast::Module) -> Option<FileItemTreeId<Mod>> {
+        let name = module.name()?.as_name();
+        let visibility = self.lower_visibility(module);
+        let kind = if module.semicolon_token().is_some() {
+            ModKind::Outline {}
+        } else {
+            ModKind::Inline {
+                items: module
+                    .item_list()
+                    .map(|list| {
+                        list.items()
+                            .flat_map(|item| self.lower_mod_item(&item, false))
+                            .flat_map(|items| items.0)
+                            .collect()
+                    })
+                    .unwrap_or_else(|| {
+                        mark::hit!(name_res_works_for_broken_modules);
+                        Box::new([]) as Box<[_]>
+                    }),
+            }
+        };
+        let ast_id = self.source_ast_id_map.ast_id(module);
+        let res = Mod { name, visibility, kind, ast_id };
+        Some(id(self.data().mods.alloc(res)))
+    }
+
+    fn lower_trait(&mut self, trait_def: &ast::TraitDef) -> Option<FileItemTreeId<Trait>> {
+        let name = trait_def.name()?.as_name();
+        let visibility = self.lower_visibility(trait_def);
+        let generic_params =
+            self.lower_generic_params_and_inner_items(GenericsOwner::Trait(trait_def), trait_def);
+        let auto = trait_def.auto_token().is_some();
+        let items = trait_def.item_list().map(|list| {
+            self.with_inherited_visibility(visibility, |this| {
+                list.items()
+                    .filter_map(|item| {
+                        let attrs = Attrs::new(&item, &this.hygiene);
+                        this.collect_inner_items(item.syntax());
+                        this.lower_assoc_item(&item).map(|item| {
+                            this.add_attrs(ModItem::from(item).into(), attrs);
+                            item
+                        })
+                    })
+                    .collect()
+            })
+        });
+        let ast_id = self.source_ast_id_map.ast_id(trait_def);
+        let res = Trait {
+            name,
+            visibility,
+            generic_params,
+            auto,
+            items: items.unwrap_or_default(),
+            ast_id,
+        };
+        Some(id(self.data().traits.alloc(res)))
+    }
+
+    fn lower_impl(&mut self, impl_def: &ast::ImplDef) -> Option<FileItemTreeId<Impl>> {
+        let generic_params =
+            self.lower_generic_params_and_inner_items(GenericsOwner::Impl, impl_def);
+        let target_trait = impl_def.target_trait().map(|tr| self.lower_type_ref(&tr));
+        let target_type = self.lower_type_ref(&impl_def.target_type()?);
+        let is_negative = impl_def.excl_token().is_some();
+
+        // We cannot use `assoc_items()` here as that does not include macro calls.
+        let items = impl_def
+            .item_list()
+            .into_iter()
+            .flat_map(|it| it.items())
+            .filter_map(|item| {
+                self.collect_inner_items(item.syntax());
+                let assoc = self.lower_assoc_item(&item)?;
+                let attrs = Attrs::new(&item, &self.hygiene);
+                self.add_attrs(ModItem::from(assoc).into(), attrs);
+                Some(assoc)
+            })
+            .collect();
+        let ast_id = self.source_ast_id_map.ast_id(impl_def);
+        let res = Impl { generic_params, target_trait, target_type, is_negative, items, ast_id };
+        Some(id(self.data().impls.alloc(res)))
+    }
+
+    fn lower_use(&mut self, use_item: &ast::UseItem) -> Vec<FileItemTreeId<Import>> {
+        // FIXME: cfg_attr
+        let is_prelude = use_item.has_atom_attr("prelude_import");
+        let visibility = self.lower_visibility(use_item);
+        let ast_id = self.source_ast_id_map.ast_id(use_item);
+
+        // Every use item can expand to many `Import`s.
+        let mut imports = Vec::new();
+        let tree = self.tree.data_mut();
+        ModPath::expand_use_item(
+            InFile::new(self.file, use_item.clone()),
+            &self.hygiene,
+            |path, _tree, is_glob, alias| {
+                imports.push(id(tree.imports.alloc(Import {
+                    path,
+                    alias,
+                    visibility,
+                    is_glob,
+                    is_prelude,
+                    ast_id,
+                })));
+            },
+        );
+
+        imports
+    }
+
+    fn lower_extern_crate(
+        &mut self,
+        extern_crate: &ast::ExternCrateItem,
+    ) -> Option<FileItemTreeId<ExternCrate>> {
+        let path = ModPath::from_name_ref(&extern_crate.name_ref()?);
+        let alias = extern_crate.alias().map(|a| {
+            a.name().map(|it| it.as_name()).map_or(ImportAlias::Underscore, ImportAlias::Alias)
+        });
+        let visibility = self.lower_visibility(extern_crate);
+        let ast_id = self.source_ast_id_map.ast_id(extern_crate);
+        // FIXME: cfg_attr
+        let is_macro_use = extern_crate.has_atom_attr("macro_use");
+
+        let res = ExternCrate { path, alias, visibility, is_macro_use, ast_id };
+        Some(id(self.data().extern_crates.alloc(res)))
+    }
+
+    fn lower_macro_call(&mut self, m: &ast::MacroCall) -> Option<FileItemTreeId<MacroCall>> {
+        let name = m.name().map(|it| it.as_name());
+        let attrs = Attrs::new(m, &self.hygiene);
+        let path = ModPath::from_src(m.path()?, &self.hygiene)?;
+
+        let ast_id = self.source_ast_id_map.ast_id(m);
+
+        // FIXME: cfg_attr
+        let export_attr = attrs.by_key("macro_export");
+
+        let is_export = export_attr.exists();
+        let is_local_inner = if is_export {
+            export_attr.tt_values().map(|it| &it.token_trees).flatten().any(|it| match it {
+                tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
+                    ident.text.contains("local_inner_macros")
+                }
+                _ => false,
+            })
+        } else {
+            false
+        };
+
+        let is_builtin = attrs.by_key("rustc_builtin_macro").exists();
+        let res = MacroCall { name, path, is_export, is_builtin, is_local_inner, ast_id };
+        Some(id(self.data().macro_calls.alloc(res)))
+    }
+
+    fn lower_extern_block(&mut self, block: &ast::ExternBlock) -> Vec<ModItem> {
+        block.extern_item_list().map_or(Vec::new(), |list| {
+            list.extern_items()
+                .filter_map(|item| {
+                    self.collect_inner_items(item.syntax());
+                    let attrs = Attrs::new(&item, &self.hygiene);
+                    let id: ModItem = match item {
+                        ast::ExternItem::FnDef(ast) => {
+                            let func = self.lower_function(&ast)?;
+                            self.data().functions[func.index].is_unsafe = true;
+                            func.into()
+                        }
+                        ast::ExternItem::StaticDef(ast) => {
+                            let statik = self.lower_static(&ast)?;
+                            statik.into()
+                        }
+                    };
+                    self.add_attrs(id.into(), attrs);
+                    Some(id)
+                })
+                .collect()
+        })
+    }
+
+    /// Lowers generics defined on `node` and collects inner items defined within.
+    fn lower_generic_params_and_inner_items(
+        &mut self,
+        owner: GenericsOwner<'_>,
+        node: &impl ast::TypeParamsOwner,
+    ) -> GenericParamsId {
+        // Generics are part of item headers and may contain inner items we need to collect.
+        if let Some(params) = node.type_param_list() {
+            self.collect_inner_items(params.syntax());
+        }
+        if let Some(clause) = node.where_clause() {
+            self.collect_inner_items(clause.syntax());
+        }
+
+        self.lower_generic_params(owner, node)
+    }
+
+    fn lower_generic_params(
+        &mut self,
+        owner: GenericsOwner<'_>,
+        node: &impl ast::TypeParamsOwner,
+    ) -> GenericParamsId {
+        let mut sm = &mut ArenaMap::default();
+        let mut generics = GenericParams::default();
+        match owner {
+            GenericsOwner::Function(func) => {
+                generics.fill(&self.body_ctx, sm, node);
+                // lower `impl Trait` in arguments
+                for param in &*func.params {
+                    generics.fill_implicit_impl_trait_args(param);
+                }
+            }
+            GenericsOwner::Struct
+            | GenericsOwner::Enum
+            | GenericsOwner::Union
+            | GenericsOwner::TypeAlias => {
+                generics.fill(&self.body_ctx, sm, node);
+            }
+            GenericsOwner::Trait(trait_def) => {
+                // traits get the Self type as an implicit first type parameter
+                let self_param_id = generics.types.alloc(TypeParamData {
+                    name: Some(name![Self]),
+                    default: None,
+                    provenance: TypeParamProvenance::TraitSelf,
+                });
+                sm.insert(self_param_id, Either::Left(trait_def.clone()));
+                // add super traits as bounds on Self
+                // i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar
+                let self_param = TypeRef::Path(name![Self].into());
+                generics.fill_bounds(&self.body_ctx, trait_def, self_param);
+
+                generics.fill(&self.body_ctx, &mut sm, node);
+            }
+            GenericsOwner::Impl => {
+                // Note that we don't add `Self` here: in `impl`s, `Self` is not a
+                // type-parameter, but rather is a type-alias for impl's target
+                // type, so this is handled by the resolver.
+                generics.fill(&self.body_ctx, &mut sm, node);
+            }
+        }
+
+        self.data().generics.alloc(generics)
+    }
+
+    fn lower_type_bounds(&mut self, node: &impl ast::TypeBoundsOwner) -> Vec<TypeBound> {
+        match node.type_bound_list() {
+            Some(bound_list) => {
+                bound_list.bounds().map(|it| TypeBound::from_ast(&self.body_ctx, it)).collect()
+            }
+            None => Vec::new(),
+        }
+    }
+
+    fn lower_visibility(&mut self, item: &impl ast::VisibilityOwner) -> RawVisibilityId {
+        let vis = match self.forced_visibility {
+            Some(vis) => return vis,
+            None => RawVisibility::from_ast_with_hygiene(item.visibility(), &self.hygiene),
+        };
+
+        self.data().vis.alloc(vis)
+    }
+
+    fn lower_type_ref(&self, type_ref: &ast::TypeRef) -> TypeRef {
+        TypeRef::from_ast(&self.body_ctx, type_ref.clone())
+    }
+    fn lower_type_ref_opt(&self, type_ref: Option<ast::TypeRef>) -> TypeRef {
+        type_ref.map(|ty| self.lower_type_ref(&ty)).unwrap_or(TypeRef::Error)
+    }
+
+    /// Forces the visibility `vis` to be used for all items lowered during execution of `f`.
+    fn with_inherited_visibility<R>(
+        &mut self,
+        vis: RawVisibilityId,
+        f: impl FnOnce(&mut Self) -> R,
+    ) -> R {
+        let old = mem::replace(&mut self.forced_visibility, Some(vis));
+        let res = f(self);
+        self.forced_visibility = old;
+        res
+    }
+
+    fn next_field_idx(&self) -> Idx<Field> {
+        Idx::from_raw(RawId::from(
+            self.tree.data.as_ref().map_or(0, |data| data.fields.len() as u32),
+        ))
+    }
+    fn next_variant_idx(&self) -> Idx<Variant> {
+        Idx::from_raw(RawId::from(
+            self.tree.data.as_ref().map_or(0, |data| data.variants.len() as u32),
+        ))
+    }
+}
+
+fn desugar_future_path(orig: TypeRef) -> Path {
+    let path = path![core::future::Future];
+    let mut generic_args: Vec<_> = std::iter::repeat(None).take(path.segments.len() - 1).collect();
+    let mut last = GenericArgs::empty();
+    let binding =
+        AssociatedTypeBinding { name: name![Output], type_ref: Some(orig), bounds: Vec::new() };
+    last.bindings.push(binding);
+    generic_args.push(Some(Arc::new(last)));
+
+    Path::from_known_path(path, generic_args)
+}
+
+enum GenericsOwner<'a> {
+    /// We need access to the partially-lowered `Function` for lowering `impl Trait` in argument
+    /// position.
+    Function(&'a Function),
+    Struct,
+    Enum,
+    Union,
+    /// The `TraitDef` is needed to fill the source map for the implicit `Self` parameter.
+    Trait(&'a ast::TraitDef),
+    TypeAlias,
+    Impl,
+}
diff --git a/crates/ra_hir_def/src/item_tree/tests.rs b/crates/ra_hir_def/src/item_tree/tests.rs
new file mode 100644
index 000000000..f26982985
--- /dev/null
+++ b/crates/ra_hir_def/src/item_tree/tests.rs
@@ -0,0 +1,439 @@
+use expect::{expect, Expect};
+use hir_expand::{db::AstDatabase, HirFileId, InFile};
+use ra_db::fixture::WithFixture;
+use ra_syntax::{ast, AstNode};
+use rustc_hash::FxHashSet;
+use std::sync::Arc;
+use stdx::format_to;
+
+use crate::{db::DefDatabase, test_db::TestDB};
+
+use super::{ItemTree, ModItem, ModKind};
+
+fn test_inner_items(ra_fixture: &str) {
+    let (db, file_id) = TestDB::with_single_file(ra_fixture);
+    let file_id = HirFileId::from(file_id);
+    let tree = db.item_tree(file_id);
+    let root = db.parse_or_expand(file_id).unwrap();
+    let ast_id_map = db.ast_id_map(file_id);
+
+    // Traverse the item tree and collect all module/impl/trait-level items as AST nodes.
+    let mut outer_items = FxHashSet::default();
+    let mut worklist = tree.top_level_items().to_vec();
+    while let Some(item) = worklist.pop() {
+        let node: ast::ModuleItem = match item {
+            ModItem::Import(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::ExternCrate(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Function(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Struct(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Union(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Enum(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Const(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Static(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::TypeAlias(it) => tree.source(&db, InFile::new(file_id, it)).into(),
+            ModItem::Mod(it) => {
+                if let ModKind::Inline { items } = &tree[it].kind {
+                    worklist.extend(&**items);
+                }
+                tree.source(&db, InFile::new(file_id, it)).into()
+            }
+            ModItem::Trait(it) => {
+                worklist.extend(tree[it].items.iter().map(|item| ModItem::from(*item)));
+                tree.source(&db, InFile::new(file_id, it)).into()
+            }
+            ModItem::Impl(it) => {
+                worklist.extend(tree[it].items.iter().map(|item| ModItem::from(*item)));
+                tree.source(&db, InFile::new(file_id, it)).into()
+            }
+            ModItem::MacroCall(_) => continue,
+        };
+
+        outer_items.insert(node);
+    }
+
+    // Now descend the root node and check that all `ast::ModuleItem`s are either recorded above, or
+    // registered as inner items.
+    for item in root.descendants().skip(1).filter_map(ast::ModuleItem::cast) {
+        if outer_items.contains(&item) {
+            continue;
+        }
+
+        let ast_id = ast_id_map.ast_id(&item);
+        assert!(!tree.inner_items(ast_id).is_empty());
+    }
+}
+
+fn item_tree(ra_fixture: &str) -> Arc<ItemTree> {
+    let (db, file_id) = TestDB::with_single_file(ra_fixture);
+    db.item_tree(file_id.into())
+}
+
+fn print_item_tree(ra_fixture: &str) -> String {
+    let tree = item_tree(ra_fixture);
+    let mut out = String::new();
+
+    format_to!(out, "inner attrs: {:?}\n\n", tree.top_level_attrs());
+    format_to!(out, "top-level items:\n");
+    for item in tree.top_level_items() {
+        fmt_mod_item(&mut out, &tree, *item);
+        format_to!(out, "\n");
+    }
+
+    if !tree.inner_items.is_empty() {
+        format_to!(out, "\ninner items:\n\n");
+        for (ast_id, items) in &tree.inner_items {
+            format_to!(out, "for AST {:?}:\n", ast_id);
+            for inner in items {
+                fmt_mod_item(&mut out, &tree, *inner);
+                format_to!(out, "\n\n");
+            }
+        }
+    }
+
+    out
+}
+
+fn fmt_mod_item(out: &mut String, tree: &ItemTree, item: ModItem) {
+    let attrs = tree.attrs(item.into());
+    if !attrs.is_empty() {
+        format_to!(out, "#[{:?}]\n", attrs);
+    }
+
+    let mut children = String::new();
+    match item {
+        ModItem::ExternCrate(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Import(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Function(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Struct(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Union(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Enum(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Const(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Static(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Trait(it) => {
+            format_to!(out, "{:?}", tree[it]);
+            for item in &*tree[it].items {
+                fmt_mod_item(&mut children, tree, ModItem::from(*item));
+                format_to!(children, "\n");
+            }
+        }
+        ModItem::Impl(it) => {
+            format_to!(out, "{:?}", tree[it]);
+            for item in &*tree[it].items {
+                fmt_mod_item(&mut children, tree, ModItem::from(*item));
+                format_to!(children, "\n");
+            }
+        }
+        ModItem::TypeAlias(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+        ModItem::Mod(it) => {
+            format_to!(out, "{:?}", tree[it]);
+            match &tree[it].kind {
+                ModKind::Inline { items } => {
+                    for item in &**items {
+                        fmt_mod_item(&mut children, tree, *item);
+                        format_to!(children, "\n");
+                    }
+                }
+                ModKind::Outline {} => {}
+            }
+        }
+        ModItem::MacroCall(it) => {
+            format_to!(out, "{:?}", tree[it]);
+        }
+    }
+
+    for line in children.lines() {
+        format_to!(out, "\n> {}", line);
+    }
+}
+
+fn check(ra_fixture: &str, expect: Expect) {
+    let actual = print_item_tree(ra_fixture);
+    expect.assert_eq(&actual);
+}
+
+#[test]
+fn smoke() {
+    check(
+        r"
+        #![attr]
+
+        #[attr_on_use]
+        use {a, b::*};
+
+        #[ext_crate]
+        extern crate krate;
+
+        #[on_trait]
+        trait Tr<U> {
+            #[assoc_ty]
+            type AssocTy: Tr<()>;
+
+            #[assoc_const]
+            const CONST: u8;
+
+            #[assoc_method]
+            fn method(&self);
+
+            #[assoc_dfl_method]
+            fn dfl_method(&mut self) {}
+        }
+
+        #[struct0]
+        struct Struct0<T = ()>;
+
+        #[struct1]
+        struct Struct1<T>(#[struct1fld] u8);
+
+        #[struct2]
+        struct Struct2<T> {
+            #[struct2fld]
+            fld: (T, ),
+        }
+
+        #[en]
+        enum En {
+            #[enum_variant]
+            Variant {
+                #[enum_field]
+                field: u8,
+            },
+        }
+
+        #[un]
+        union Un {
+            #[union_fld]
+            fld: u16,
+        }
+    ",
+        expect![[r##"
+            inner attrs: Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr"))] }, input: None }]) }
+
+            top-level items:
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_on_use"))] }, input: None }]) }]
+            Import { path: ModPath { kind: Plain, segments: [Name(Text("a"))] }, alias: None, visibility: RawVisibilityId("pub(self)"), is_glob: false, is_prelude: false, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UseItem>(0) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_on_use"))] }, input: None }]) }]
+            Import { path: ModPath { kind: Plain, segments: [Name(Text("b"))] }, alias: None, visibility: RawVisibilityId("pub(self)"), is_glob: true, is_prelude: false, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UseItem>(0) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("ext_crate"))] }, input: None }]) }]
+            ExternCrate { path: ModPath { kind: Plain, segments: [Name(Text("krate"))] }, alias: None, visibility: RawVisibilityId("pub(self)"), is_macro_use: false, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::ExternCrateItem>(1) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("on_trait"))] }, input: None }]) }]
+            Trait { name: Name(Text("Tr")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(0), auto: false, items: [TypeAlias(Idx::<TypeAlias>(0)), Const(Idx::<Const>(0)), Function(Idx::<Function>(0)), Function(Idx::<Function>(1))], ast_id: FileAstId::<ra_syntax::ast::generated::nodes::TraitDef>(2) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("assoc_ty"))] }, input: None }]) }]
+            > TypeAlias { name: Name(Text("AssocTy")), visibility: RawVisibilityId("pub(self)"), bounds: [Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("Tr"))] }, generic_args: [Some(GenericArgs { args: [Type(Tuple([]))], has_self_type: false, bindings: [] })] })], generic_params: GenericParamsId(4294967295), type_ref: None, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::TypeAliasDef>(8) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("assoc_const"))] }, input: None }]) }]
+            > Const { name: Some(Name(Text("CONST"))), visibility: RawVisibilityId("pub(self)"), type_ref: Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("u8"))] }, generic_args: [None] }), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::ConstDef>(9) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("assoc_method"))] }, input: None }]) }]
+            > Function { name: Name(Text("method")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: true, is_unsafe: false, params: [Reference(Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("Self"))] }, generic_args: [None] }), Shared)], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(10) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("assoc_dfl_method"))] }, input: None }]) }]
+            > Function { name: Name(Text("dfl_method")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: true, is_unsafe: false, params: [Reference(Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("Self"))] }, generic_args: [None] }), Mut)], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(11) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct0"))] }, input: None }]) }]
+            Struct { name: Name(Text("Struct0")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(1), fields: Unit, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(3), kind: Unit }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct1"))] }, input: None }]) }]
+            Struct { name: Name(Text("Struct1")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(2), fields: Tuple(IdRange::<ra_hir_def::item_tree::Field>(0..1)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(4), kind: Tuple }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("struct2"))] }, input: None }]) }]
+            Struct { name: Name(Text("Struct2")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(3), fields: Record(IdRange::<ra_hir_def::item_tree::Field>(1..2)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::StructDef>(5), kind: Record }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("en"))] }, input: None }]) }]
+            Enum { name: Name(Text("En")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), variants: IdRange::<ra_hir_def::item_tree::Variant>(0..1), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::EnumDef>(6) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("un"))] }, input: None }]) }]
+            Union { name: Name(Text("Un")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), fields: Record(IdRange::<ra_hir_def::item_tree::Field>(3..4)), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::UnionDef>(7) }
+        "##]],
+    );
+}
+
+#[test]
+fn simple_inner_items() {
+    check(
+        r"
+        impl<T:A> D for Response<T> {
+            fn foo() {
+                end();
+                fn end<W: Write>() {
+                    let _x: T = loop {};
+                }
+            }
+        }
+    ",
+        expect![[r#"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            Impl { generic_params: GenericParamsId(0), target_trait: Some(Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("D"))] }, generic_args: [None] })), target_type: Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("Response"))] }, generic_args: [Some(GenericArgs { args: [Type(Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("T"))] }, generic_args: [None] }))], has_self_type: false, bindings: [] })] }), is_negative: false, items: [Function(Idx::<Function>(1))], ast_id: FileAstId::<ra_syntax::ast::generated::nodes::ImplDef>(0) }
+            > Function { name: Name(Text("foo")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(1) }
+
+            inner items:
+
+            for AST FileAstId::<ra_syntax::ast::generated::nodes::ModuleItem>(2):
+            Function { name: Name(Text("end")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(1), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(2) }
+
+        "#]],
+    );
+}
+
+#[test]
+fn extern_attrs() {
+    check(
+        r#"
+        #[block_attr]
+        extern "C" {
+            #[attr_a]
+            fn a() {}
+            #[attr_b]
+            fn b() {}
+        }
+    "#,
+        expect![[r##"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_a"))] }, input: None }, Attr { path: ModPath { kind: Plain, segments: [Name(Text("block_attr"))] }, input: None }]) }]
+            Function { name: Name(Text("a")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: true, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(1) }
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_b"))] }, input: None }, Attr { path: ModPath { kind: Plain, segments: [Name(Text("block_attr"))] }, input: None }]) }]
+            Function { name: Name(Text("b")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: true, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(2) }
+        "##]],
+    );
+}
+
+#[test]
+fn trait_attrs() {
+    check(
+        r#"
+        #[trait_attr]
+        trait Tr {
+            #[attr_a]
+            fn a() {}
+            #[attr_b]
+            fn b() {}
+        }
+    "#,
+        expect![[r##"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("trait_attr"))] }, input: None }]) }]
+            Trait { name: Name(Text("Tr")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(0), auto: false, items: [Function(Idx::<Function>(0)), Function(Idx::<Function>(1))], ast_id: FileAstId::<ra_syntax::ast::generated::nodes::TraitDef>(0) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_a"))] }, input: None }]) }]
+            > Function { name: Name(Text("a")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(1) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_b"))] }, input: None }]) }]
+            > Function { name: Name(Text("b")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(2) }
+        "##]],
+    );
+}
+
+#[test]
+fn impl_attrs() {
+    check(
+        r#"
+        #[impl_attr]
+        impl Ty {
+            #[attr_a]
+            fn a() {}
+            #[attr_b]
+            fn b() {}
+        }
+    "#,
+        expect![[r##"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("impl_attr"))] }, input: None }]) }]
+            Impl { generic_params: GenericParamsId(4294967295), target_trait: None, target_type: Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("Ty"))] }, generic_args: [None] }), is_negative: false, items: [Function(Idx::<Function>(0)), Function(Idx::<Function>(1))], ast_id: FileAstId::<ra_syntax::ast::generated::nodes::ImplDef>(0) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_a"))] }, input: None }]) }]
+            > Function { name: Name(Text("a")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(1) }
+            > #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("attr_b"))] }, input: None }]) }]
+            > Function { name: Name(Text("b")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(2) }
+        "##]],
+    );
+}
+
+#[test]
+fn cursed_inner_items() {
+    test_inner_items(
+        r"
+        struct S<T: Trait = [u8; { fn f() {} 0 }]>(T);
+
+        enum En {
+            Var1 {
+                t: [(); { trait Inner {} 0 }],
+            },
+
+            Var2([u16; { enum Inner {} 0 }]),
+        }
+
+        type Ty = [En; { struct Inner; 0 }];
+
+        impl En {
+            fn assoc() {
+                trait InnerTrait<T = [u8; { fn f() {} }]> {}
+                struct InnerStruct<T = [u8; { fn f() {} }]> {}
+                impl<T = [u8; { fn f() {} }]> InnerTrait for InnerStruct {}
+            }
+        }
+
+        trait Tr<T = [u8; { fn f() {} }]> {
+            type AssocTy = [u8; { fn f() {} }];
+
+            const AssocConst: [u8; { fn f() {} }];
+        }
+    ",
+    );
+}
+
+#[test]
+fn inner_item_attrs() {
+    check(
+        r"
+        fn foo() {
+            #[on_inner]
+            fn inner() {}
+        }
+    ",
+        expect![[r##"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            Function { name: Name(Text("foo")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(0) }
+
+            inner items:
+
+            for AST FileAstId::<ra_syntax::ast::generated::nodes::ModuleItem>(1):
+            #[Attrs { entries: Some([Attr { path: ModPath { kind: Plain, segments: [Name(Text("on_inner"))] }, input: None }]) }]
+            Function { name: Name(Text("inner")), visibility: RawVisibilityId("pub(self)"), generic_params: GenericParamsId(4294967295), has_self_param: false, is_unsafe: false, params: [], is_varargs: false, ret_type: Tuple([]), ast_id: FileAstId::<ra_syntax::ast::generated::nodes::FnDef>(1) }
+
+        "##]],
+    );
+}
+
+#[test]
+fn assoc_item_macros() {
+    check(
+        r"
+        impl S {
+            items!();
+        }
+    ",
+        expect![[r#"
+            inner attrs: Attrs { entries: None }
+
+            top-level items:
+            Impl { generic_params: GenericParamsId(4294967295), target_trait: None, target_type: Path(Path { type_anchor: None, mod_path: ModPath { kind: Plain, segments: [Name(Text("S"))] }, generic_args: [None] }), is_negative: false, items: [MacroCall(Idx::<MacroCall>(0))], ast_id: FileAstId::<ra_syntax::ast::generated::nodes::ImplDef>(0) }
+            > MacroCall { name: None, path: ModPath { kind: Plain, segments: [Name(Text("items"))] }, is_export: false, is_local_inner: false, is_builtin: false, ast_id: FileAstId::<ra_syntax::ast::generated::nodes::MacroCall>(1) }
+        "#]],
+    );
+}
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index 5325a2760..87000fe98 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -25,6 +25,8 @@ pub mod item_scope;
 pub mod dyn_map;
 pub mod keys;
 
+pub mod item_tree;
+
 pub mod adt;
 pub mod data;
 pub mod generics;
@@ -43,11 +45,12 @@ pub mod child_by_source;
 
 pub mod visibility;
 pub mod find_path;
+pub mod import_map;
 
 #[cfg(test)]
 mod test_db;
 
-use std::hash::Hash;
+use std::hash::{Hash, Hasher};
 
 use hir_expand::{
     ast_id_map::FileAstId, eager::expand_eager_macro, hygiene::Hygiene, AstId, HirFileId, InFile,
@@ -55,10 +58,14 @@ use hir_expand::{
 };
 use ra_arena::Idx;
 use ra_db::{impl_intern_key, salsa, CrateId};
-use ra_syntax::{ast, AstNode};
+use ra_syntax::ast;
 
-use crate::body::Expander;
 use crate::builtin_type::BuiltinType;
+use item_tree::{
+    Const, Enum, Function, Impl, ItemTreeId, ItemTreeNode, ModItem, Static, Struct, Trait,
+    TypeAlias, Union,
+};
+use stdx::impl_from;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ModuleId {
@@ -69,16 +76,62 @@ pub struct ModuleId {
 /// An ID of a module, **local** to a specific crate
 pub type LocalModuleId = Idx<nameres::ModuleData>;
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ItemLoc<N: AstNode> {
+#[derive(Debug)]
+pub struct ItemLoc<N: ItemTreeNode> {
     pub container: ContainerId,
-    pub ast_id: AstId<N>,
+    pub id: ItemTreeId<N>,
+}
+
+impl<N: ItemTreeNode> Clone for ItemLoc<N> {
+    fn clone(&self) -> Self {
+        Self { container: self.container, id: self.id }
+    }
+}
+
+impl<N: ItemTreeNode> Copy for ItemLoc<N> {}
+
+impl<N: ItemTreeNode> PartialEq for ItemLoc<N> {
+    fn eq(&self, other: &Self) -> bool {
+        self.container == other.container && self.id == other.id
+    }
+}
+
+impl<N: ItemTreeNode> Eq for ItemLoc<N> {}
+
+impl<N: ItemTreeNode> Hash for ItemLoc<N> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.container.hash(state);
+        self.id.hash(state);
+    }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct AssocItemLoc<N: AstNode> {
+#[derive(Debug)]
+pub struct AssocItemLoc<N: ItemTreeNode> {
     pub container: AssocContainerId,
-    pub ast_id: AstId<N>,
+    pub id: ItemTreeId<N>,
+}
+
+impl<N: ItemTreeNode> Clone for AssocItemLoc<N> {
+    fn clone(&self) -> Self {
+        Self { container: self.container, id: self.id }
+    }
+}
+
+impl<N: ItemTreeNode> Copy for AssocItemLoc<N> {}
+
+impl<N: ItemTreeNode> PartialEq for AssocItemLoc<N> {
+    fn eq(&self, other: &Self) -> bool {
+        self.container == other.container && self.id == other.id
+    }
+}
+
+impl<N: ItemTreeNode> Eq for AssocItemLoc<N> {}
+
+impl<N: ItemTreeNode> Hash for AssocItemLoc<N> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.container.hash(state);
+        self.id.hash(state);
+    }
 }
 
 macro_rules! impl_intern {
@@ -103,22 +156,22 @@ macro_rules! impl_intern {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FunctionId(salsa::InternId);
-type FunctionLoc = AssocItemLoc<ast::FnDef>;
+type FunctionLoc = AssocItemLoc<Function>;
 impl_intern!(FunctionId, FunctionLoc, intern_function, lookup_intern_function);
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct StructId(salsa::InternId);
-type StructLoc = ItemLoc<ast::StructDef>;
+type StructLoc = ItemLoc<Struct>;
 impl_intern!(StructId, StructLoc, intern_struct, lookup_intern_struct);
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct UnionId(salsa::InternId);
-pub type UnionLoc = ItemLoc<ast::UnionDef>;
+pub type UnionLoc = ItemLoc<Union>;
 impl_intern!(UnionId, UnionLoc, intern_union, lookup_intern_union);
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct EnumId(salsa::InternId);
-pub type EnumLoc = ItemLoc<ast::EnumDef>;
+pub type EnumLoc = ItemLoc<Enum>;
 impl_intern!(EnumId, EnumLoc, intern_enum, lookup_intern_enum);
 
 // FIXME: rename to `VariantId`, only enums can ave variants
@@ -140,27 +193,27 @@ pub type LocalFieldId = Idx<adt::FieldData>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ConstId(salsa::InternId);
-type ConstLoc = AssocItemLoc<ast::ConstDef>;
+type ConstLoc = AssocItemLoc<Const>;
 impl_intern!(ConstId, ConstLoc, intern_const, lookup_intern_const);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StaticId(salsa::InternId);
-pub type StaticLoc = ItemLoc<ast::StaticDef>;
+pub type StaticLoc = ItemLoc<Static>;
 impl_intern!(StaticId, StaticLoc, intern_static, lookup_intern_static);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TraitId(salsa::InternId);
-pub type TraitLoc = ItemLoc<ast::TraitDef>;
+pub type TraitLoc = ItemLoc<Trait>;
 impl_intern!(TraitId, TraitLoc, intern_trait, lookup_intern_trait);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TypeAliasId(salsa::InternId);
-type TypeAliasLoc = AssocItemLoc<ast::TypeAliasDef>;
+type TypeAliasLoc = AssocItemLoc<TypeAlias>;
 impl_intern!(TypeAliasId, TypeAliasLoc, intern_type_alias, lookup_intern_type_alias);
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct ImplId(salsa::InternId);
-type ImplLoc = ItemLoc<ast::ImplDef>;
+type ImplLoc = ItemLoc<Impl>;
 impl_intern!(ImplId, ImplLoc, intern_impl, lookup_intern_impl);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -171,25 +224,6 @@ pub struct TypeParamId {
 
 pub type LocalTypeParamId = Idx<generics::TypeParamData>;
 
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-            $($(
-                impl From<$sv> for $e {
-                    fn from(it: $sv) -> $e {
-                        $e::$v($v::$sv(it))
-                    }
-                }
-            )*)?
-        )*
-    }
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum ContainerId {
     ModuleId(ModuleId),
@@ -202,16 +236,16 @@ pub enum AssocContainerId {
     ImplId(ImplId),
     TraitId(TraitId),
 }
-impl_froms!(AssocContainerId: ContainerId);
+impl_from!(ContainerId for AssocContainerId);
 
 /// A Data Type
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub enum AdtId {
     StructId(StructId),
     UnionId(UnionId),
     EnumId(EnumId),
 }
-impl_froms!(AdtId: StructId, UnionId, EnumId);
+impl_from!(StructId, UnionId, EnumId for AdtId);
 
 /// The defs which can be visible in the module.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -227,8 +261,8 @@ pub enum ModuleDefId {
     TypeAliasId(TypeAliasId),
     BuiltinType(BuiltinType),
 }
-impl_froms!(
-    ModuleDefId: ModuleId,
+impl_from!(
+    ModuleId,
     FunctionId,
     AdtId(StructId, EnumId, UnionId),
     EnumVariantId,
@@ -237,6 +271,7 @@ impl_froms!(
     TraitId,
     TypeAliasId,
     BuiltinType
+    for ModuleDefId
 );
 
 /// The defs which have a body.
@@ -247,7 +282,7 @@ pub enum DefWithBodyId {
     ConstId(ConstId),
 }
 
-impl_froms!(DefWithBodyId: FunctionId, ConstId, StaticId);
+impl_from!(FunctionId, ConstId, StaticId for DefWithBodyId);
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum AssocItemId {
@@ -259,7 +294,7 @@ pub enum AssocItemId {
 // sure that you can only turn actual assoc items into AssocItemIds. This would
 // require not implementing From, and instead having some checked way of
 // casting them, and somehow making the constructors private, which would be annoying.
-impl_froms!(AssocItemId: FunctionId, ConstId, TypeAliasId);
+impl_from!(FunctionId, ConstId, TypeAliasId for AssocItemId);
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
 pub enum GenericDefId {
@@ -274,14 +309,15 @@ pub enum GenericDefId {
     // consts can have type parameters from their parents (i.e. associated consts of traits)
     ConstId(ConstId),
 }
-impl_froms!(
-    GenericDefId: FunctionId,
+impl_from!(
+    FunctionId,
     AdtId(StructId, EnumId, UnionId),
     TraitId,
     TypeAliasId,
     ImplId,
     EnumVariantId,
     ConstId
+    for GenericDefId
 );
 
 impl From<AssocItemId> for GenericDefId {
@@ -309,8 +345,8 @@ pub enum AttrDefId {
     ImplId(ImplId),
 }
 
-impl_froms!(
-    AttrDefId: ModuleId,
+impl_from!(
+    ModuleId,
     FieldId,
     AdtId(StructId, EnumId, UnionId),
     EnumVariantId,
@@ -321,6 +357,7 @@ impl_froms!(
     TypeAliasId,
     MacroDefId,
     ImplId
+    for AttrDefId
 );
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -329,7 +366,7 @@ pub enum VariantId {
     StructId(StructId),
     UnionId(UnionId),
 }
-impl_froms!(VariantId: EnumVariantId, StructId, UnionId);
+impl_from!(EnumVariantId, StructId, UnionId for VariantId);
 
 trait Intern {
     type ID;
@@ -364,7 +401,7 @@ impl HasModule for AssocContainerId {
     }
 }
 
-impl<N: AstNode> HasModule for AssocItemLoc<N> {
+impl<N: ItemTreeNode> HasModule for AssocItemLoc<N> {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         self.container.module(db)
     }
@@ -391,6 +428,16 @@ impl HasModule for DefWithBodyId {
     }
 }
 
+impl DefWithBodyId {
+    pub fn as_mod_item(self, db: &dyn db::DefDatabase) -> ModItem {
+        match self {
+            DefWithBodyId::FunctionId(it) => it.lookup(db).id.value.into(),
+            DefWithBodyId::StaticId(it) => it.lookup(db).id.value.into(),
+            DefWithBodyId::ConstId(it) => it.lookup(db).id.value.into(),
+        }
+    }
+}
+
 impl HasModule for GenericDefId {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         match self {
@@ -416,6 +463,7 @@ pub trait AsMacroCall {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId>;
 }
@@ -424,13 +472,14 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
         let h = Hygiene::new(db.upcast(), self.file_id);
         let path = path::ModPath::from_src(self.value.path()?, &h)?;
 
-        AstIdWithPath::new(ast_id.file_id, ast_id.value, path).as_call_id(db, resolver)
+        AstIdWithPath::new(ast_id.file_id, ast_id.value, path).as_call_id(db, krate, resolver)
     }
 }
 
@@ -451,6 +500,7 @@ impl AsMacroCall for AstIdWithPath<ast::MacroCall> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let def: MacroDefId = resolver(self.path.clone())?;
@@ -460,13 +510,13 @@ impl AsMacroCall for AstIdWithPath<ast::MacroCall> {
             let hygiene = Hygiene::new(db.upcast(), self.ast_id.file_id);
 
             Some(
-                expand_eager_macro(db.upcast(), macro_call, def, &|path: ast::Path| {
+                expand_eager_macro(db.upcast(), krate, macro_call, def, &|path: ast::Path| {
                     resolver(path::ModPath::from_src(path, &hygiene)?)
                 })?
                 .into(),
             )
         } else {
-            Some(def.as_lazy_macro(db.upcast(), MacroCallKind::FnLike(self.ast_id)).into())
+            Some(def.as_lazy_macro(db.upcast(), krate, MacroCallKind::FnLike(self.ast_id)).into())
         }
     }
 }
@@ -475,12 +525,14 @@ impl AsMacroCall for AstIdWithPath<ast::ModuleItem> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let def = resolver(self.path.clone())?;
         Some(
             def.as_lazy_macro(
                 db.upcast(),
+                krate,
                 MacroCallKind::Attr(self.ast_id, self.path.segments.last()?.to_string()),
             )
             .into(),
diff --git a/crates/ra_hir_def/src/nameres.rs b/crates/ra_hir_def/src/nameres.rs
index f279c2ad4..b279bdeef 100644
--- a/crates/ra_hir_def/src/nameres.rs
+++ b/crates/ra_hir_def/src/nameres.rs
@@ -47,7 +47,6 @@
 //! path and, upon success, we run macro expansion and "collect module" phase on
 //! the result
 
-pub(crate) mod raw;
 mod collector;
 mod mod_resolution;
 mod path_resolution;
@@ -104,6 +103,7 @@ pub enum ModuleOrigin {
     },
     /// Note that non-inline modules, by definition, live inside non-macro file.
     File {
+        is_mod_rs: bool,
         declaration: AstId<ast::Module>,
         definition: FileId,
     },
@@ -119,13 +119,6 @@ impl Default for ModuleOrigin {
 }
 
 impl ModuleOrigin {
-    pub(crate) fn not_sure_file(file: Option<FileId>, declaration: AstId<ast::Module>) -> Self {
-        match file {
-            None => ModuleOrigin::Inline { definition: declaration },
-            Some(definition) => ModuleOrigin::File { declaration, definition },
-        }
-    }
-
     fn declaration(&self) -> Option<AstId<ast::Module>> {
         match self {
             ModuleOrigin::File { declaration: module, .. }
@@ -296,7 +289,6 @@ pub enum ModuleSource {
 
 mod diagnostics {
     use hir_expand::diagnostics::DiagnosticSink;
-    use ra_db::RelativePathBuf;
     use ra_syntax::{ast, AstPtr};
 
     use crate::{db::DefDatabase, diagnostics::UnresolvedModule, nameres::LocalModuleId, AstId};
@@ -306,7 +298,7 @@ mod diagnostics {
         UnresolvedModule {
             module: LocalModuleId,
             declaration: AstId<ast::Module>,
-            candidate: RelativePathBuf,
+            candidate: String,
         },
     }
 
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 353a31ad4..d85a86c0a 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -4,6 +4,7 @@
 //! resolves imports and expands macros.
 
 use hir_expand::{
+    ast_id_map::FileAstId,
     builtin_derive::find_builtin_derive,
     builtin_macro::find_builtin_macro,
     name::{name, AsName, Name},
@@ -19,25 +20,33 @@ use test_utils::mark;
 use crate::{
     attr::Attrs,
     db::DefDatabase,
+    item_scope::{ImportType, PerNsGlobImports},
+    item_tree::{
+        self, FileItemTreeId, ItemTree, ItemTreeId, MacroCall, Mod, ModItem, ModKind, StructDefKind,
+    },
     nameres::{
         diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
-        raw, BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
+        BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
     },
     path::{ImportAlias, ModPath, PathKind},
     per_ns::PerNs,
-    visibility::Visibility,
+    visibility::{RawVisibility, Visibility},
     AdtId, AsMacroCall, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId,
     FunctionLoc, ImplLoc, Intern, LocalModuleId, ModuleDefId, ModuleId, StaticLoc, StructLoc,
     TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
+const GLOB_RECURSION_LIMIT: usize = 100;
+const EXPANSION_DEPTH_LIMIT: usize = 128;
+const FIXED_POINT_LIMIT: usize = 8192;
+
 pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
     let crate_graph = db.crate_graph();
 
     // populate external prelude
     for dep in &crate_graph[def_map.krate].dependencies {
-        let dep_def_map = db.crate_def_map(dep.crate_id);
         log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
+        let dep_def_map = db.crate_def_map(dep.crate_id);
         def_map.extern_prelude.insert(
             dep.as_name(),
             ModuleId { krate: dep.crate_id, local_id: dep_def_map.root }.into(),
@@ -76,6 +85,7 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: CrateDefMap) -> Cr
         mod_dirs: FxHashMap::default(),
         cfg_options,
         proc_macros,
+        from_glob_import: Default::default(),
     };
     collector.collect();
     collector.finish()
@@ -102,10 +112,50 @@ impl PartialResolvedImport {
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
+struct Import {
+    pub path: ModPath,
+    pub alias: Option<ImportAlias>,
+    pub visibility: RawVisibility,
+    pub is_glob: bool,
+    pub is_prelude: bool,
+    pub is_extern_crate: bool,
+    pub is_macro_use: bool,
+}
+
+impl Import {
+    fn from_use(tree: &ItemTree, id: FileItemTreeId<item_tree::Import>) -> Self {
+        let it = &tree[id];
+        let visibility = &tree[it.visibility];
+        Self {
+            path: it.path.clone(),
+            alias: it.alias.clone(),
+            visibility: visibility.clone(),
+            is_glob: it.is_glob,
+            is_prelude: it.is_prelude,
+            is_extern_crate: false,
+            is_macro_use: false,
+        }
+    }
+
+    fn from_extern_crate(tree: &ItemTree, id: FileItemTreeId<item_tree::ExternCrate>) -> Self {
+        let it = &tree[id];
+        let visibility = &tree[it.visibility];
+        Self {
+            path: it.path.clone(),
+            alias: it.alias.clone(),
+            visibility: visibility.clone(),
+            is_glob: false,
+            is_prelude: false,
+            is_extern_crate: true,
+            is_macro_use: it.is_macro_use,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
 struct ImportDirective {
     module_id: LocalModuleId,
-    import_id: raw::Import,
-    import: raw::ImportData,
+    import: Import,
     status: PartialResolvedImport,
 }
 
@@ -123,6 +173,13 @@ struct DeriveDirective {
     ast_id: AstIdWithPath<ast::ModuleItem>,
 }
 
+struct DefData<'a> {
+    id: ModuleDefId,
+    name: &'a Name,
+    visibility: &'a RawVisibility,
+    has_constructor: bool,
+}
+
 /// Walks the tree of module recursively
 struct DefCollector<'a> {
     db: &'a dyn DefDatabase,
@@ -135,12 +192,13 @@ struct DefCollector<'a> {
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
     cfg_options: &'a CfgOptions,
     proc_macros: Vec<(Name, ProcMacroExpander)>,
+    from_glob_import: PerNsGlobImports,
 }
 
 impl DefCollector<'_> {
     fn collect(&mut self) {
         let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id;
-        let raw_items = self.db.raw_items(file_id.into());
+        let item_tree = self.db.item_tree(file_id.into());
         let module_id = self.def_map.root;
         self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id };
         ModCollector {
@@ -148,10 +206,10 @@ impl DefCollector<'_> {
             macro_depth: 0,
             module_id,
             file_id: file_id.into(),
-            raw_items: &raw_items,
+            item_tree: &item_tree,
             mod_dir: ModDir::root(),
         }
-        .collect(raw_items.items());
+        .collect(item_tree.top_level_items());
 
         // main name resolution fixed-point loop.
         let mut i = 0;
@@ -163,7 +221,7 @@ impl DefCollector<'_> {
                 ReachedFixedPoint::Yes => break,
                 ReachedFixedPoint::No => i += 1,
             }
-            if i == 10000 {
+            if i == FIXED_POINT_LIMIT {
                 log::error!("name resolution is stuck");
                 break;
             }
@@ -254,6 +312,7 @@ impl DefCollector<'_> {
                 self.def_map.root,
                 &[(name, PerNs::macros(macro_, Visibility::Public))],
                 Visibility::Public,
+                ImportType::Named,
             );
         }
     }
@@ -279,6 +338,7 @@ impl DefCollector<'_> {
             self.def_map.root,
             &[(name, PerNs::macros(macro_, Visibility::Public))],
             Visibility::Public,
+            ImportType::Named,
         );
     }
 
@@ -286,7 +346,7 @@ impl DefCollector<'_> {
     fn import_macros_from_extern_crate(
         &mut self,
         current_module_id: LocalModuleId,
-        import: &raw::ImportData,
+        import: &item_tree::ExternCrate,
     ) {
         log::debug!(
             "importing macros from extern crate: {:?} ({:?})",
@@ -332,7 +392,6 @@ impl DefCollector<'_> {
             let imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
             for mut directive in imports {
                 directive.status = self.resolve_import(directive.module_id, &directive.import);
-
                 match directive.status {
                     PartialResolvedImport::Indeterminate(_) => {
                         self.record_resolved_import(&directive);
@@ -352,11 +411,7 @@ impl DefCollector<'_> {
         }
     }
 
-    fn resolve_import(
-        &self,
-        module_id: LocalModuleId,
-        import: &raw::ImportData,
-    ) -> PartialResolvedImport {
+    fn resolve_import(&self, module_id: LocalModuleId, import: &Import) -> PartialResolvedImport {
         log::debug!("resolving import: {:?} ({:?})", import, self.def_map.edition);
         if import.is_extern_crate {
             let res = self.def_map.resolve_name_in_extern_prelude(
@@ -430,7 +485,7 @@ impl DefCollector<'_> {
                             .filter(|(_, res)| !res.is_none())
                             .collect::<Vec<_>>();
 
-                        self.update(module_id, &items, vis);
+                        self.update(module_id, &items, vis, ImportType::Glob);
                     } else {
                         // glob import from same crate => we do an initial
                         // import, and then need to propagate any further
@@ -452,7 +507,7 @@ impl DefCollector<'_> {
                             .filter(|(_, res)| !res.is_none())
                             .collect::<Vec<_>>();
 
-                        self.update(module_id, &items, vis);
+                        self.update(module_id, &items, vis, ImportType::Glob);
                         // record the glob import in case we add further items
                         let glob = self.glob_imports.entry(m.local_id).or_default();
                         if !glob.iter().any(|(mid, _)| *mid == module_id) {
@@ -482,7 +537,7 @@ impl DefCollector<'_> {
                             (name, res)
                         })
                         .collect::<Vec<_>>();
-                    self.update(module_id, &resolutions, vis);
+                    self.update(module_id, &resolutions, vis, ImportType::Glob);
                 }
                 Some(d) => {
                     log::debug!("glob import {:?} from non-module/enum {:?}", import, d);
@@ -508,15 +563,22 @@ impl DefCollector<'_> {
                         }
                     }
 
-                    self.update(module_id, &[(name, def)], vis);
+                    self.update(module_id, &[(name, def)], vis, ImportType::Named);
                 }
                 None => mark::hit!(bogus_paths),
             }
         }
     }
 
-    fn update(&mut self, module_id: LocalModuleId, resolutions: &[(Name, PerNs)], vis: Visibility) {
-        self.update_recursive(module_id, resolutions, vis, 0)
+    fn update(
+        &mut self,
+        module_id: LocalModuleId,
+        resolutions: &[(Name, PerNs)],
+        vis: Visibility,
+        import_type: ImportType,
+    ) {
+        self.db.check_canceled();
+        self.update_recursive(module_id, resolutions, vis, import_type, 0)
     }
 
     fn update_recursive(
@@ -526,16 +588,22 @@ impl DefCollector<'_> {
         // All resolutions are imported with this visibility; the visibilies in
         // the `PerNs` values are ignored and overwritten
         vis: Visibility,
+        import_type: ImportType,
         depth: usize,
     ) {
-        if depth > 100 {
+        if depth > GLOB_RECURSION_LIMIT {
             // prevent stack overflows (but this shouldn't be possible)
             panic!("infinite recursion in glob imports!");
         }
         let scope = &mut self.def_map.modules[module_id].scope;
         let mut changed = false;
         for (name, res) in resolutions {
-            changed |= scope.push_res(name.clone(), res.with_visibility(vis));
+            changed |= scope.push_res_with_import(
+                &mut self.from_glob_import,
+                (module_id, name.clone()),
+                res.with_visibility(vis),
+                import_type,
+            );
         }
 
         if !changed {
@@ -546,15 +614,22 @@ impl DefCollector<'_> {
             .get(&module_id)
             .into_iter()
             .flat_map(|v| v.iter())
+            .filter(|(glob_importing_module, _)| {
+                // we know all resolutions have the same visibility (`vis`), so we
+                // just need to check that once
+                vis.is_visible_from_def_map(&self.def_map, *glob_importing_module)
+            })
             .cloned()
             .collect::<Vec<_>>();
+
         for (glob_importing_module, glob_import_vis) in glob_imports {
-            // we know all resolutions have the same visibility (`vis`), so we
-            // just need to check that once
-            if !vis.is_visible_from_def_map(&self.def_map, glob_importing_module) {
-                continue;
-            }
-            self.update_recursive(glob_importing_module, resolutions, glob_import_vis, depth + 1);
+            self.update_recursive(
+                glob_importing_module,
+                resolutions,
+                glob_import_vis,
+                ImportType::Glob,
+                depth + 1,
+            );
         }
     }
 
@@ -571,16 +646,18 @@ impl DefCollector<'_> {
                 return false;
             }
 
-            if let Some(call_id) = directive.ast_id.as_call_id(self.db, |path| {
-                let resolved_res = self.def_map.resolve_path_fp_with_macro(
-                    self.db,
-                    ResolveMode::Other,
-                    directive.module_id,
-                    &path,
-                    BuiltinShadowMode::Module,
-                );
-                resolved_res.resolved_def.take_macros()
-            }) {
+            if let Some(call_id) =
+                directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| {
+                    let resolved_res = self.def_map.resolve_path_fp_with_macro(
+                        self.db,
+                        ResolveMode::Other,
+                        directive.module_id,
+                        &path,
+                        BuiltinShadowMode::Module,
+                    );
+                    resolved_res.resolved_def.take_macros()
+                })
+            {
                 resolved.push((directive.module_id, call_id, directive.depth));
                 res = ReachedFixedPoint::No;
                 return false;
@@ -589,9 +666,10 @@ impl DefCollector<'_> {
             true
         });
         attribute_macros.retain(|directive| {
-            if let Some(call_id) = directive
-                .ast_id
-                .as_call_id(self.db, |path| self.resolve_attribute_macro(&directive, &path))
+            if let Some(call_id) =
+                directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| {
+                    self.resolve_attribute_macro(&directive, &path)
+                })
             {
                 resolved.push((directive.module_id, call_id, 0));
                 res = ReachedFixedPoint::No;
@@ -605,10 +683,6 @@ impl DefCollector<'_> {
         self.unexpanded_attribute_macros = attribute_macros;
 
         for (module_id, macro_call_id, depth) in resolved {
-            if depth > 1024 {
-                log::debug!("Max macro expansion depth reached");
-                continue;
-            }
             self.collect_macro_expansion(module_id, macro_call_id, depth);
         }
 
@@ -645,18 +719,23 @@ impl DefCollector<'_> {
         macro_call_id: MacroCallId,
         depth: usize,
     ) {
+        if depth > EXPANSION_DEPTH_LIMIT {
+            mark::hit!(macro_expansion_overflow);
+            log::warn!("macro expansion is too deep");
+            return;
+        }
         let file_id: HirFileId = macro_call_id.as_file();
-        let raw_items = self.db.raw_items(file_id);
+        let item_tree = self.db.item_tree(file_id);
         let mod_dir = self.mod_dirs[&module_id].clone();
         ModCollector {
             def_collector: &mut *self,
             macro_depth: depth,
             file_id,
             module_id,
-            raw_items: &raw_items,
+            item_tree: &item_tree,
             mod_dir,
         }
-        .collect(raw_items.items());
+        .collect(item_tree.top_level_items());
     }
 
     fn finish(self) -> CrateDefMap {
@@ -670,12 +749,12 @@ struct ModCollector<'a, 'b> {
     macro_depth: usize,
     module_id: LocalModuleId,
     file_id: HirFileId,
-    raw_items: &'a raw::RawItems,
+    item_tree: &'a ItemTree,
     mod_dir: ModDir,
 }
 
 impl ModCollector<'_, '_> {
-    fn collect(&mut self, items: &[raw::RawItem]) {
+    fn collect(&mut self, items: &[ModItem]) {
         // Note: don't assert that inserted value is fresh: it's simply not true
         // for macros.
         self.def_collector.mod_dirs.insert(self.module_id, self.mod_dir.clone());
@@ -692,64 +771,205 @@ impl ModCollector<'_, '_> {
         // `#[macro_use] extern crate` is hoisted to imports macros before collecting
         // any other items.
         for item in items {
-            if self.is_cfg_enabled(&item.attrs) {
-                if let raw::RawItemKind::Import(import_id) = item.kind {
-                    let import = self.raw_items[import_id].clone();
-                    if import.is_extern_crate && import.is_macro_use {
+            if self.is_cfg_enabled(self.item_tree.attrs((*item).into())) {
+                if let ModItem::ExternCrate(id) = item {
+                    let import = self.item_tree[*id].clone();
+                    if import.is_macro_use {
                         self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
                     }
                 }
             }
         }
 
-        for item in items {
-            if self.is_cfg_enabled(&item.attrs) {
-                match item.kind {
-                    raw::RawItemKind::Module(m) => {
-                        self.collect_module(&self.raw_items[m], &item.attrs)
-                    }
-                    raw::RawItemKind::Import(import_id) => {
+        for &item in items {
+            let attrs = self.item_tree.attrs(item.into());
+            if self.is_cfg_enabled(attrs) {
+                let module =
+                    ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
+                let container = ContainerId::ModuleId(module);
+
+                let mut def = None;
+                match item {
+                    ModItem::Mod(m) => self.collect_module(&self.item_tree[m], attrs),
+                    ModItem::Import(import_id) => {
                         self.def_collector.unresolved_imports.push(ImportDirective {
                             module_id: self.module_id,
-                            import_id,
-                            import: self.raw_items[import_id].clone(),
+                            import: Import::from_use(&self.item_tree, import_id),
                             status: PartialResolvedImport::Unresolved,
                         })
                     }
-                    raw::RawItemKind::Def(def) => {
-                        self.define_def(&self.raw_items[def], &item.attrs)
+                    ModItem::ExternCrate(import_id) => {
+                        self.def_collector.unresolved_imports.push(ImportDirective {
+                            module_id: self.module_id,
+                            import: Import::from_extern_crate(&self.item_tree, import_id),
+                            status: PartialResolvedImport::Unresolved,
+                        })
                     }
-                    raw::RawItemKind::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
-                    raw::RawItemKind::Impl(imp) => {
+                    ModItem::MacroCall(mac) => self.collect_macro(&self.item_tree[mac]),
+                    ModItem::Impl(imp) => {
                         let module = ModuleId {
                             krate: self.def_collector.def_map.krate,
                             local_id: self.module_id,
                         };
                         let container = ContainerId::ModuleId(module);
-                        let ast_id = self.raw_items[imp].ast_id;
-                        let impl_id =
-                            ImplLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                                .intern(self.def_collector.db);
+                        let impl_id = ImplLoc { container, id: ItemTreeId::new(self.file_id, imp) }
+                            .intern(self.def_collector.db);
                         self.def_collector.def_map.modules[self.module_id]
                             .scope
                             .define_impl(impl_id)
                     }
+                    ModItem::Function(id) => {
+                        let func = &self.item_tree[id];
+                        def = Some(DefData {
+                            id: FunctionLoc {
+                                container: container.into(),
+                                id: ItemTreeId::new(self.file_id, id),
+                            }
+                            .intern(self.def_collector.db)
+                            .into(),
+                            name: &func.name,
+                            visibility: &self.item_tree[func.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                    ModItem::Struct(id) => {
+                        let it = &self.item_tree[id];
+
+                        // FIXME: check attrs to see if this is an attribute macro invocation;
+                        // in which case we don't add the invocation, just a single attribute
+                        // macro invocation
+                        self.collect_derives(attrs, it.ast_id.upcast());
+
+                        def = Some(DefData {
+                            id: StructLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                                .intern(self.def_collector.db)
+                                .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: it.kind != StructDefKind::Record,
+                        });
+                    }
+                    ModItem::Union(id) => {
+                        let it = &self.item_tree[id];
+
+                        // FIXME: check attrs to see if this is an attribute macro invocation;
+                        // in which case we don't add the invocation, just a single attribute
+                        // macro invocation
+                        self.collect_derives(attrs, it.ast_id.upcast());
+
+                        def = Some(DefData {
+                            id: UnionLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                                .intern(self.def_collector.db)
+                                .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                    ModItem::Enum(id) => {
+                        let it = &self.item_tree[id];
+
+                        // FIXME: check attrs to see if this is an attribute macro invocation;
+                        // in which case we don't add the invocation, just a single attribute
+                        // macro invocation
+                        self.collect_derives(attrs, it.ast_id.upcast());
+
+                        def = Some(DefData {
+                            id: EnumLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                                .intern(self.def_collector.db)
+                                .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                    ModItem::Const(id) => {
+                        let it = &self.item_tree[id];
+
+                        if let Some(name) = &it.name {
+                            def = Some(DefData {
+                                id: ConstLoc {
+                                    container: container.into(),
+                                    id: ItemTreeId::new(self.file_id, id),
+                                }
+                                .intern(self.def_collector.db)
+                                .into(),
+                                name,
+                                visibility: &self.item_tree[it.visibility],
+                                has_constructor: false,
+                            });
+                        }
+                    }
+                    ModItem::Static(id) => {
+                        let it = &self.item_tree[id];
+
+                        def = Some(DefData {
+                            id: StaticLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                                .intern(self.def_collector.db)
+                                .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                    ModItem::Trait(id) => {
+                        let it = &self.item_tree[id];
+
+                        def = Some(DefData {
+                            id: TraitLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                                .intern(self.def_collector.db)
+                                .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                    ModItem::TypeAlias(id) => {
+                        let it = &self.item_tree[id];
+
+                        def = Some(DefData {
+                            id: TypeAliasLoc {
+                                container: container.into(),
+                                id: ItemTreeId::new(self.file_id, id),
+                            }
+                            .intern(self.def_collector.db)
+                            .into(),
+                            name: &it.name,
+                            visibility: &self.item_tree[it.visibility],
+                            has_constructor: false,
+                        });
+                    }
+                }
+
+                if let Some(DefData { id, name, visibility, has_constructor }) = def {
+                    self.def_collector.def_map.modules[self.module_id].scope.define_def(id);
+                    let vis = self
+                        .def_collector
+                        .def_map
+                        .resolve_visibility(self.def_collector.db, self.module_id, visibility)
+                        .unwrap_or(Visibility::Public);
+                    self.def_collector.update(
+                        self.module_id,
+                        &[(name.clone(), PerNs::from_def(id, vis, has_constructor))],
+                        vis,
+                        ImportType::Named,
+                    )
                 }
             }
         }
     }
 
-    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &Attrs) {
+    fn collect_module(&mut self, module: &Mod, attrs: &Attrs) {
         let path_attr = attrs.by_key("path").string_value();
         let is_macro_use = attrs.by_key("macro_use").exists();
-        match module {
+        match &module.kind {
             // inline module, just recurse
-            raw::ModuleData::Definition { name, visibility, items, ast_id } => {
+            ModKind::Inline { items } => {
                 let module_id = self.push_child_module(
-                    name.clone(),
-                    AstId::new(self.file_id, *ast_id),
+                    module.name.clone(),
+                    AstId::new(self.file_id, module.ast_id),
                     None,
-                    &visibility,
+                    &self.item_tree[module.visibility],
                 );
 
                 ModCollector {
@@ -757,8 +977,8 @@ impl ModCollector<'_, '_> {
                     macro_depth: self.macro_depth,
                     module_id,
                     file_id: self.file_id,
-                    raw_items: self.raw_items,
-                    mod_dir: self.mod_dir.descend_into_definition(name, path_attr),
+                    item_tree: self.item_tree,
+                    mod_dir: self.mod_dir.descend_into_definition(&module.name, path_attr),
                 }
                 .collect(&*items);
                 if is_macro_use {
@@ -766,31 +986,31 @@ impl ModCollector<'_, '_> {
                 }
             }
             // out of line module, resolve, parse and recurse
-            raw::ModuleData::Declaration { name, visibility, ast_id } => {
-                let ast_id = AstId::new(self.file_id, *ast_id);
+            ModKind::Outline {} => {
+                let ast_id = AstId::new(self.file_id, module.ast_id);
                 match self.mod_dir.resolve_declaration(
                     self.def_collector.db,
                     self.file_id,
-                    name,
+                    &module.name,
                     path_attr,
                 ) {
-                    Ok((file_id, mod_dir)) => {
+                    Ok((file_id, is_mod_rs, mod_dir)) => {
                         let module_id = self.push_child_module(
-                            name.clone(),
+                            module.name.clone(),
                             ast_id,
-                            Some(file_id),
-                            &visibility,
+                            Some((file_id, is_mod_rs)),
+                            &self.item_tree[module.visibility],
                         );
-                        let raw_items = self.def_collector.db.raw_items(file_id.into());
+                        let item_tree = self.def_collector.db.item_tree(file_id.into());
                         ModCollector {
                             def_collector: &mut *self.def_collector,
                             macro_depth: self.macro_depth,
                             module_id,
                             file_id: file_id.into(),
-                            raw_items: &raw_items,
+                            item_tree: &item_tree,
                             mod_dir,
                         }
-                        .collect(raw_items.items());
+                        .collect(item_tree.top_level_items());
                         if is_macro_use {
                             self.import_all_legacy_macros(module_id);
                         }
@@ -811,7 +1031,7 @@ impl ModCollector<'_, '_> {
         &mut self,
         name: Name,
         declaration: AstId<ast::Module>,
-        definition: Option<FileId>,
+        definition: Option<(FileId, bool)>,
         visibility: &crate::visibility::RawVisibility,
     ) -> LocalModuleId {
         let vis = self
@@ -822,7 +1042,12 @@ impl ModCollector<'_, '_> {
         let modules = &mut self.def_collector.def_map.modules;
         let res = modules.alloc(ModuleData::default());
         modules[res].parent = Some(self.module_id);
-        modules[res].origin = ModuleOrigin::not_sure_file(definition, declaration);
+        modules[res].origin = match definition {
+            None => ModuleOrigin::Inline { definition: declaration },
+            Some((definition, is_mod_rs)) => {
+                ModuleOrigin::File { declaration, definition, is_mod_rs }
+            }
+        };
         for (name, mac) in modules[self.module_id].scope.collect_legacy_macros() {
             modules[res].scope.define_legacy_macro(name, mac)
         }
@@ -830,81 +1055,16 @@ impl ModCollector<'_, '_> {
         let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: res };
         let def: ModuleDefId = module.into();
         self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
-        self.def_collector.update(self.module_id, &[(name, PerNs::from_def(def, vis, false))], vis);
-        res
-    }
-
-    fn define_def(&mut self, def: &raw::DefData, attrs: &Attrs) {
-        let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
-        // FIXME: check attrs to see if this is an attribute macro invocation;
-        // in which case we don't add the invocation, just a single attribute
-        // macro invocation
-        self.collect_derives(attrs, def);
-
-        let name = def.name.clone();
-        let container = ContainerId::ModuleId(module);
-        let vis = &def.visibility;
-        let mut has_constructor = false;
-
-        let def: ModuleDefId = match def.kind {
-            raw::DefKind::Function(ast_id) => FunctionLoc {
-                container: container.into(),
-                ast_id: AstId::new(self.file_id, ast_id),
-            }
-            .intern(self.def_collector.db)
-            .into(),
-            raw::DefKind::Struct(ast_id, mode) => {
-                has_constructor = mode != raw::StructDefKind::Record;
-                StructLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::Union(ast_id) => {
-                UnionLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::Enum(ast_id) => {
-                EnumLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::Const(ast_id) => {
-                ConstLoc { container: container.into(), ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::Static(ast_id) => {
-                StaticLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::Trait(ast_id) => {
-                TraitLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db)
-                    .into()
-            }
-            raw::DefKind::TypeAlias(ast_id) => TypeAliasLoc {
-                container: container.into(),
-                ast_id: AstId::new(self.file_id, ast_id),
-            }
-            .intern(self.def_collector.db)
-            .into(),
-        };
-        self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
-        let vis = self
-            .def_collector
-            .def_map
-            .resolve_visibility(self.def_collector.db, self.module_id, vis)
-            .unwrap_or(Visibility::Public);
         self.def_collector.update(
             self.module_id,
-            &[(name, PerNs::from_def(def, vis, has_constructor))],
+            &[(name, PerNs::from_def(def, vis, false))],
             vis,
-        )
+            ImportType::Named,
+        );
+        res
     }
 
-    fn collect_derives(&mut self, attrs: &Attrs, def: &raw::DefData) {
+    fn collect_derives(&mut self, attrs: &Attrs, ast_id: FileAstId<ast::ModuleItem>) {
         for derive_subtree in attrs.by_key("derive").tt_values() {
             // for #[derive(Copy, Clone)], `derive_subtree` is the `(Copy, Clone)` subtree
             for tt in &derive_subtree.token_trees {
@@ -915,7 +1075,7 @@ impl ModCollector<'_, '_> {
                 };
                 let path = ModPath::from_tt_ident(ident);
 
-                let ast_id = AstIdWithPath::new(self.file_id, def.kind.ast_id(), path);
+                let ast_id = AstIdWithPath::new(self.file_id, ast_id, path);
                 self.def_collector
                     .unexpanded_attribute_macros
                     .push(DeriveDirective { module_id: self.module_id, ast_id });
@@ -923,11 +1083,11 @@ impl ModCollector<'_, '_> {
         }
     }
 
-    fn collect_macro(&mut self, mac: &raw::MacroData) {
+    fn collect_macro(&mut self, mac: &MacroCall) {
         let mut ast_id = AstIdWithPath::new(self.file_id, mac.ast_id, mac.path.clone());
 
         // Case 0: builtin macros
-        if mac.builtin {
+        if mac.is_builtin {
             if let Some(name) = &mac.name {
                 let krate = self.def_collector.def_map.krate;
                 if let Some(macro_id) = find_builtin_macro(name, krate, ast_id.ast_id) {
@@ -935,7 +1095,7 @@ impl ModCollector<'_, '_> {
                         self.module_id,
                         name.clone(),
                         macro_id,
-                        mac.export,
+                        mac.is_export,
                     );
                     return;
                 }
@@ -949,19 +1109,26 @@ impl ModCollector<'_, '_> {
                     ast_id: Some(ast_id.ast_id),
                     krate: Some(self.def_collector.def_map.krate),
                     kind: MacroDefKind::Declarative,
-                    local_inner: mac.local_inner,
+                    local_inner: mac.is_local_inner,
                 };
-                self.def_collector.define_macro(self.module_id, name.clone(), macro_id, mac.export);
+                self.def_collector.define_macro(
+                    self.module_id,
+                    name.clone(),
+                    macro_id,
+                    mac.is_export,
+                );
             }
             return;
         }
 
         // Case 2: try to resolve in legacy scope and expand macro_rules
-        if let Some(macro_call_id) = ast_id.as_call_id(self.def_collector.db, |path| {
-            path.as_ident().and_then(|name| {
-                self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+        if let Some(macro_call_id) =
+            ast_id.as_call_id(self.def_collector.db, self.def_collector.def_map.krate, |path| {
+                path.as_ident().and_then(|name| {
+                    self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+                })
             })
-        }) {
+        {
             self.def_collector.unexpanded_macros.push(MacroDirective {
                 module_id: self.module_id,
                 ast_id,
@@ -1022,6 +1189,7 @@ mod tests {
             mod_dirs: FxHashMap::default(),
             cfg_options: &CfgOptions::default(),
             proc_macros: Default::default(),
+            from_glob_import: Default::default(),
         };
         collector.collect();
         collector.def_map
diff --git a/crates/ra_hir_def/src/nameres/mod_resolution.rs b/crates/ra_hir_def/src/nameres/mod_resolution.rs
index 386c5cade..953961632 100644
--- a/crates/ra_hir_def/src/nameres/mod_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/mod_resolution.rs
@@ -1,23 +1,24 @@
 //! This module resolves `mod foo;` declaration to file.
 use hir_expand::name::Name;
-use ra_db::{FileId, RelativePathBuf};
+use ra_db::FileId;
 use ra_syntax::SmolStr;
 
 use crate::{db::DefDatabase, HirFileId};
 
 #[derive(Clone, Debug)]
 pub(super) struct ModDir {
-    /// `.` for `mod.rs`, `lib.rs`
-    /// `./foo` for `foo.rs`
-    /// `./foo/bar` for `mod bar { mod x; }` nested in `foo.rs`
-    path: RelativePathBuf,
+    /// `` for `mod.rs`, `lib.rs`
+    /// `foo/` for `foo.rs`
+    /// `foo/bar/` for `mod bar { mod x; }` nested in `foo.rs`
+    /// Invariant: path.is_empty() || path.ends_with('/')
+    dir_path: DirPath,
     /// inside `./foo.rs`, mods with `#[path]` should *not* be relative to `./foo/`
     root_non_dir_owner: bool,
 }
 
 impl ModDir {
     pub(super) fn root() -> ModDir {
-        ModDir { path: RelativePathBuf::default(), root_non_dir_owner: false }
+        ModDir { dir_path: DirPath::empty(), root_non_dir_owner: false }
     }
 
     pub(super) fn descend_into_definition(
@@ -25,17 +26,21 @@ impl ModDir {
         name: &Name,
         attr_path: Option<&SmolStr>,
     ) -> ModDir {
-        let mut path = self.path.clone();
-        match attr_to_path(attr_path) {
-            None => path.push(&name.to_string()),
+        let path = match attr_path.map(|it| it.as_str()) {
+            None => {
+                let mut path = self.dir_path.clone();
+                path.push(&name.to_string());
+                path
+            }
             Some(attr_path) => {
-                if self.root_non_dir_owner {
-                    assert!(path.pop());
+                let mut path = self.dir_path.join_attr(attr_path, self.root_non_dir_owner);
+                if !(path.is_empty() || path.ends_with('/')) {
+                    path.push('/')
                 }
-                path.push(attr_path);
+                DirPath::new(path)
             }
-        }
-        ModDir { path, root_non_dir_owner: false }
+        };
+        ModDir { dir_path: path, root_non_dir_owner: false }
     }
 
     pub(super) fn resolve_declaration(
@@ -44,37 +49,91 @@ impl ModDir {
         file_id: HirFileId,
         name: &Name,
         attr_path: Option<&SmolStr>,
-    ) -> Result<(FileId, ModDir), RelativePathBuf> {
+    ) -> Result<(FileId, bool, ModDir), String> {
         let file_id = file_id.original_file(db.upcast());
 
         let mut candidate_files = Vec::new();
-        match attr_to_path(attr_path) {
+        match attr_path {
             Some(attr_path) => {
-                let base =
-                    if self.root_non_dir_owner { self.path.parent().unwrap() } else { &self.path };
-                candidate_files.push(base.join(attr_path))
+                candidate_files.push(self.dir_path.join_attr(attr_path, self.root_non_dir_owner))
             }
             None => {
-                candidate_files.push(self.path.join(&format!("{}.rs", name)));
-                candidate_files.push(self.path.join(&format!("{}/mod.rs", name)));
+                candidate_files.push(format!("{}{}.rs", self.dir_path.0, name));
+                candidate_files.push(format!("{}{}/mod.rs", self.dir_path.0, name));
             }
         };
 
         for candidate in candidate_files.iter() {
-            if let Some(file_id) = db.resolve_relative_path(file_id, candidate) {
-                let mut root_non_dir_owner = false;
-                let mut mod_path = RelativePathBuf::new();
-                if !(candidate.ends_with("mod.rs") || attr_path.is_some()) {
-                    root_non_dir_owner = true;
-                    mod_path.push(&name.to_string());
-                }
-                return Ok((file_id, ModDir { path: mod_path, root_non_dir_owner }));
+            if let Some(file_id) = db.resolve_path(file_id, candidate.as_str()) {
+                let is_mod_rs = candidate.ends_with("mod.rs");
+
+                let (dir_path, root_non_dir_owner) = if is_mod_rs || attr_path.is_some() {
+                    (DirPath::empty(), false)
+                } else {
+                    (DirPath::new(format!("{}/", name)), true)
+                };
+                return Ok((file_id, is_mod_rs, ModDir { dir_path, root_non_dir_owner }));
             }
         }
         Err(candidate_files.remove(0))
     }
 }
 
-fn attr_to_path(attr: Option<&SmolStr>) -> Option<RelativePathBuf> {
-    attr.and_then(|it| RelativePathBuf::from_path(&it.replace("\\", "/")).ok())
+#[derive(Clone, Debug)]
+struct DirPath(String);
+
+impl DirPath {
+    fn assert_invariant(&self) {
+        assert!(self.0.is_empty() || self.0.ends_with('/'));
+    }
+    fn new(repr: String) -> DirPath {
+        let res = DirPath(repr);
+        res.assert_invariant();
+        res
+    }
+    fn empty() -> DirPath {
+        DirPath::new(String::new())
+    }
+    fn push(&mut self, name: &str) {
+        self.0.push_str(name);
+        self.0.push('/');
+        self.assert_invariant();
+    }
+    fn parent(&self) -> Option<&str> {
+        if self.0.is_empty() {
+            return None;
+        };
+        let idx =
+            self.0[..self.0.len() - '/'.len_utf8()].rfind('/').map_or(0, |it| it + '/'.len_utf8());
+        Some(&self.0[..idx])
+    }
+    /// So this is the case which doesn't really work I think if we try to be
+    /// 100% platform agnostic:
+    ///
+    /// ```
+    /// mod a {
+    ///     #[path="C://sad/face"]
+    ///     mod b { mod c; }
+    /// }
+    /// ```
+    ///
+    /// Here, we need to join logical dir path to a string path from an
+    /// attribute. Ideally, we should somehow losslessly communicate the whole
+    /// construction to `FileLoader`.
+    fn join_attr(&self, mut attr: &str, relative_to_parent: bool) -> String {
+        let base = if relative_to_parent { self.parent().unwrap() } else { &self.0 };
+
+        if attr.starts_with("./") {
+            attr = &attr["./".len()..];
+        }
+        let tmp;
+        let attr = if attr.contains('\\') {
+            tmp = attr.replace('\\', "/");
+            &tmp
+        } else {
+            attr
+        };
+        let res = format!("{}{}", base, attr);
+        res
+    }
 }
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
deleted file mode 100644
index f44baa579..000000000
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ /dev/null
@@ -1,482 +0,0 @@
-//! Lowers syntax tree of a rust file into a raw representation of containing
-//! items, *without* attaching them to a module structure.
-//!
-//! That is, raw items don't have semantics, just as syntax, but, unlike syntax,
-//! they don't change with trivial source code edits, making them a great tool
-//! for building salsa recomputation firewalls.
-
-use std::{ops::Index, sync::Arc};
-
-use hir_expand::{
-    ast_id_map::AstIdMap,
-    hygiene::Hygiene,
-    name::{AsName, Name},
-};
-use ra_arena::{Arena, Idx};
-use ra_prof::profile;
-use ra_syntax::{
-    ast::{self, AttrsOwner, NameOwner, VisibilityOwner},
-    AstNode,
-};
-use test_utils::mark;
-
-use crate::{
-    attr::Attrs,
-    db::DefDatabase,
-    path::{ImportAlias, ModPath},
-    visibility::RawVisibility,
-    FileAstId, HirFileId, InFile,
-};
-
-/// `RawItems` is a set of top-level items in a file (except for impls).
-///
-/// It is the input to name resolution algorithm. `RawItems` are not invalidated
-/// on most edits.
-#[derive(Debug, Default, PartialEq, Eq)]
-pub struct RawItems {
-    modules: Arena<ModuleData>,
-    imports: Arena<ImportData>,
-    defs: Arena<DefData>,
-    macros: Arena<MacroData>,
-    impls: Arena<ImplData>,
-    /// items for top-level module
-    items: Vec<RawItem>,
-}
-
-impl RawItems {
-    pub(crate) fn raw_items_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<RawItems> {
-        let _p = profile("raw_items_query");
-        let mut collector = RawItemsCollector {
-            raw_items: RawItems::default(),
-            source_ast_id_map: db.ast_id_map(file_id),
-            file_id,
-            hygiene: Hygiene::new(db.upcast(), file_id),
-        };
-        if let Some(node) = db.parse_or_expand(file_id) {
-            if let Some(source_file) = ast::SourceFile::cast(node.clone()) {
-                collector.process_module(None, source_file);
-            } else if let Some(item_list) = ast::MacroItems::cast(node) {
-                collector.process_module(None, item_list);
-            }
-        }
-        let raw_items = collector.raw_items;
-        Arc::new(raw_items)
-    }
-
-    pub(super) fn items(&self) -> &[RawItem] {
-        &self.items
-    }
-}
-
-impl Index<Idx<ModuleData>> for RawItems {
-    type Output = ModuleData;
-    fn index(&self, idx: Idx<ModuleData>) -> &ModuleData {
-        &self.modules[idx]
-    }
-}
-
-impl Index<Import> for RawItems {
-    type Output = ImportData;
-    fn index(&self, idx: Import) -> &ImportData {
-        &self.imports[idx]
-    }
-}
-
-impl Index<Idx<DefData>> for RawItems {
-    type Output = DefData;
-    fn index(&self, idx: Idx<DefData>) -> &DefData {
-        &self.defs[idx]
-    }
-}
-
-impl Index<Idx<MacroData>> for RawItems {
-    type Output = MacroData;
-    fn index(&self, idx: Idx<MacroData>) -> &MacroData {
-        &self.macros[idx]
-    }
-}
-
-impl Index<Idx<ImplData>> for RawItems {
-    type Output = ImplData;
-    fn index(&self, idx: Idx<ImplData>) -> &ImplData {
-        &self.impls[idx]
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Clone)]
-pub(super) struct RawItem {
-    pub(super) attrs: Attrs,
-    pub(super) kind: RawItemKind,
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum RawItemKind {
-    Module(Idx<ModuleData>),
-    Import(Import),
-    Def(Idx<DefData>),
-    Macro(Idx<MacroData>),
-    Impl(Idx<ImplData>),
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub(super) enum ModuleData {
-    Declaration {
-        name: Name,
-        visibility: RawVisibility,
-        ast_id: FileAstId<ast::Module>,
-    },
-    Definition {
-        name: Name,
-        visibility: RawVisibility,
-        ast_id: FileAstId<ast::Module>,
-        items: Vec<RawItem>,
-    },
-}
-
-pub(crate) type Import = Idx<ImportData>;
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct ImportData {
-    pub(super) path: ModPath,
-    pub(super) alias: Option<ImportAlias>,
-    pub(super) is_glob: bool,
-    pub(super) is_prelude: bool,
-    pub(super) is_extern_crate: bool,
-    pub(super) is_macro_use: bool,
-    pub(super) visibility: RawVisibility,
-}
-
-// type Def = Idx<DefData>;
-
-#[derive(Debug, PartialEq, Eq)]
-pub(super) struct DefData {
-    pub(super) name: Name,
-    pub(super) kind: DefKind,
-    pub(super) visibility: RawVisibility,
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum StructDefKind {
-    Record,
-    Tuple,
-    Unit,
-}
-
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum DefKind {
-    Function(FileAstId<ast::FnDef>),
-    Struct(FileAstId<ast::StructDef>, StructDefKind),
-    Union(FileAstId<ast::UnionDef>),
-    Enum(FileAstId<ast::EnumDef>),
-    Const(FileAstId<ast::ConstDef>),
-    Static(FileAstId<ast::StaticDef>),
-    Trait(FileAstId<ast::TraitDef>),
-    TypeAlias(FileAstId<ast::TypeAliasDef>),
-}
-
-impl DefKind {
-    pub fn ast_id(self) -> FileAstId<ast::ModuleItem> {
-        match self {
-            DefKind::Function(it) => it.upcast(),
-            DefKind::Struct(it, _) => it.upcast(),
-            DefKind::Union(it) => it.upcast(),
-            DefKind::Enum(it) => it.upcast(),
-            DefKind::Const(it) => it.upcast(),
-            DefKind::Static(it) => it.upcast(),
-            DefKind::Trait(it) => it.upcast(),
-            DefKind::TypeAlias(it) => it.upcast(),
-        }
-    }
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub(super) struct MacroData {
-    pub(super) ast_id: FileAstId<ast::MacroCall>,
-    pub(super) path: ModPath,
-    pub(super) name: Option<Name>,
-    pub(super) export: bool,
-    pub(super) local_inner: bool,
-    pub(super) builtin: bool,
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub(super) struct ImplData {
-    pub(super) ast_id: FileAstId<ast::ImplDef>,
-}
-
-struct RawItemsCollector {
-    raw_items: RawItems,
-    source_ast_id_map: Arc<AstIdMap>,
-    file_id: HirFileId,
-    hygiene: Hygiene,
-}
-
-impl RawItemsCollector {
-    fn process_module(
-        &mut self,
-        current_module: Option<Idx<ModuleData>>,
-        body: impl ast::ModuleItemOwner,
-    ) {
-        for item in body.items() {
-            self.add_item(current_module, item)
-        }
-    }
-
-    fn add_item(&mut self, current_module: Option<Idx<ModuleData>>, item: ast::ModuleItem) {
-        let attrs = self.parse_attrs(&item);
-        let visibility = RawVisibility::from_ast_with_hygiene(item.visibility(), &self.hygiene);
-        let (kind, name) = match item {
-            ast::ModuleItem::Module(module) => {
-                self.add_module(current_module, module);
-                return;
-            }
-            ast::ModuleItem::UseItem(use_item) => {
-                self.add_use_item(current_module, use_item);
-                return;
-            }
-            ast::ModuleItem::ExternCrateItem(extern_crate) => {
-                self.add_extern_crate_item(current_module, extern_crate);
-                return;
-            }
-            ast::ModuleItem::ImplDef(it) => {
-                self.add_impl(current_module, it);
-                return;
-            }
-            ast::ModuleItem::StructDef(it) => {
-                let kind = match it.kind() {
-                    ast::StructKind::Record(_) => StructDefKind::Record,
-                    ast::StructKind::Tuple(_) => StructDefKind::Tuple,
-                    ast::StructKind::Unit => StructDefKind::Unit,
-                };
-                let id = self.source_ast_id_map.ast_id(&it);
-                let name = it.name();
-                (DefKind::Struct(id, kind), name)
-            }
-            ast::ModuleItem::UnionDef(it) => {
-                let id = self.source_ast_id_map.ast_id(&it);
-                let name = it.name();
-                (DefKind::Union(id), name)
-            }
-            ast::ModuleItem::EnumDef(it) => {
-                (DefKind::Enum(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::FnDef(it) => {
-                (DefKind::Function(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::TraitDef(it) => {
-                (DefKind::Trait(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::TypeAliasDef(it) => {
-                (DefKind::TypeAlias(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::ConstDef(it) => {
-                (DefKind::Const(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::StaticDef(it) => {
-                (DefKind::Static(self.source_ast_id_map.ast_id(&it)), it.name())
-            }
-            ast::ModuleItem::MacroCall(it) => {
-                self.add_macro(current_module, it);
-                return;
-            }
-            ast::ModuleItem::ExternBlock(it) => {
-                self.add_extern_block(current_module, it);
-                return;
-            }
-        };
-        if let Some(name) = name {
-            let name = name.as_name();
-            let def = self.raw_items.defs.alloc(DefData { name, kind, visibility });
-            self.push_item(current_module, attrs, RawItemKind::Def(def));
-        }
-    }
-
-    fn add_extern_block(
-        &mut self,
-        current_module: Option<Idx<ModuleData>>,
-        block: ast::ExternBlock,
-    ) {
-        if let Some(items) = block.extern_item_list() {
-            for item in items.extern_items() {
-                let attrs = self.parse_attrs(&item);
-                let visibility =
-                    RawVisibility::from_ast_with_hygiene(item.visibility(), &self.hygiene);
-                let (kind, name) = match item {
-                    ast::ExternItem::FnDef(it) => {
-                        (DefKind::Function(self.source_ast_id_map.ast_id(&it)), it.name())
-                    }
-                    ast::ExternItem::StaticDef(it) => {
-                        (DefKind::Static(self.source_ast_id_map.ast_id(&it)), it.name())
-                    }
-                };
-
-                if let Some(name) = name {
-                    let name = name.as_name();
-                    let def = self.raw_items.defs.alloc(DefData { name, kind, visibility });
-                    self.push_item(current_module, attrs, RawItemKind::Def(def));
-                }
-            }
-        }
-    }
-
-    fn add_module(&mut self, current_module: Option<Idx<ModuleData>>, module: ast::Module) {
-        let name = match module.name() {
-            Some(it) => it.as_name(),
-            None => return,
-        };
-        let attrs = self.parse_attrs(&module);
-        let visibility = RawVisibility::from_ast_with_hygiene(module.visibility(), &self.hygiene);
-
-        let ast_id = self.source_ast_id_map.ast_id(&module);
-        if module.semicolon_token().is_some() {
-            let item =
-                self.raw_items.modules.alloc(ModuleData::Declaration { name, visibility, ast_id });
-            self.push_item(current_module, attrs, RawItemKind::Module(item));
-            return;
-        }
-
-        if let Some(item_list) = module.item_list() {
-            let item = self.raw_items.modules.alloc(ModuleData::Definition {
-                name,
-                visibility,
-                ast_id,
-                items: Vec::new(),
-            });
-            self.process_module(Some(item), item_list);
-            self.push_item(current_module, attrs, RawItemKind::Module(item));
-            return;
-        }
-        mark::hit!(name_res_works_for_broken_modules);
-    }
-
-    fn add_use_item(&mut self, current_module: Option<Idx<ModuleData>>, use_item: ast::UseItem) {
-        // FIXME: cfg_attr
-        let is_prelude = use_item.has_atom_attr("prelude_import");
-        let attrs = self.parse_attrs(&use_item);
-        let visibility = RawVisibility::from_ast_with_hygiene(use_item.visibility(), &self.hygiene);
-
-        let mut buf = Vec::new();
-        ModPath::expand_use_item(
-            InFile { value: use_item, file_id: self.file_id },
-            &self.hygiene,
-            |path, _use_tree, is_glob, alias| {
-                let import_data = ImportData {
-                    path,
-                    alias,
-                    is_glob,
-                    is_prelude,
-                    is_extern_crate: false,
-                    is_macro_use: false,
-                    visibility: visibility.clone(),
-                };
-                buf.push(import_data);
-            },
-        );
-        for import_data in buf {
-            self.push_import(current_module, attrs.clone(), import_data);
-        }
-    }
-
-    fn add_extern_crate_item(
-        &mut self,
-        current_module: Option<Idx<ModuleData>>,
-        extern_crate: ast::ExternCrateItem,
-    ) {
-        if let Some(name_ref) = extern_crate.name_ref() {
-            let path = ModPath::from_name_ref(&name_ref);
-            let visibility =
-                RawVisibility::from_ast_with_hygiene(extern_crate.visibility(), &self.hygiene);
-            let alias = extern_crate.alias().map(|a| {
-                a.name().map(|it| it.as_name()).map_or(ImportAlias::Underscore, ImportAlias::Alias)
-            });
-            let attrs = self.parse_attrs(&extern_crate);
-            // FIXME: cfg_attr
-            let is_macro_use = extern_crate.has_atom_attr("macro_use");
-            let import_data = ImportData {
-                path,
-                alias,
-                is_glob: false,
-                is_prelude: false,
-                is_extern_crate: true,
-                is_macro_use,
-                visibility,
-            };
-            self.push_import(current_module, attrs, import_data);
-        }
-    }
-
-    fn add_macro(&mut self, current_module: Option<Idx<ModuleData>>, m: ast::MacroCall) {
-        let attrs = self.parse_attrs(&m);
-        let path = match m.path().and_then(|path| ModPath::from_src(path, &self.hygiene)) {
-            Some(it) => it,
-            _ => return,
-        };
-
-        let name = m.name().map(|it| it.as_name());
-        let ast_id = self.source_ast_id_map.ast_id(&m);
-
-        // FIXME: cfg_attr
-        let export_attr = attrs.by_key("macro_export");
-
-        let export = export_attr.exists();
-        let local_inner = if export {
-            export_attr.tt_values().map(|it| &it.token_trees).flatten().any(|it| match it {
-                tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
-                    ident.text.contains("local_inner_macros")
-                }
-                _ => false,
-            })
-        } else {
-            false
-        };
-
-        let builtin = attrs.by_key("rustc_builtin_macro").exists();
-
-        let m = self.raw_items.macros.alloc(MacroData {
-            ast_id,
-            path,
-            name,
-            export,
-            local_inner,
-            builtin,
-        });
-        self.push_item(current_module, attrs, RawItemKind::Macro(m));
-    }
-
-    fn add_impl(&mut self, current_module: Option<Idx<ModuleData>>, imp: ast::ImplDef) {
-        let attrs = self.parse_attrs(&imp);
-        let ast_id = self.source_ast_id_map.ast_id(&imp);
-        let imp = self.raw_items.impls.alloc(ImplData { ast_id });
-        self.push_item(current_module, attrs, RawItemKind::Impl(imp))
-    }
-
-    fn push_import(
-        &mut self,
-        current_module: Option<Idx<ModuleData>>,
-        attrs: Attrs,
-        data: ImportData,
-    ) {
-        let import = self.raw_items.imports.alloc(data);
-        self.push_item(current_module, attrs, RawItemKind::Import(import))
-    }
-
-    fn push_item(
-        &mut self,
-        current_module: Option<Idx<ModuleData>>,
-        attrs: Attrs,
-        kind: RawItemKind,
-    ) {
-        match current_module {
-            Some(module) => match &mut self.raw_items.modules[module] {
-                ModuleData::Definition { items, .. } => items,
-                ModuleData::Declaration { .. } => unreachable!(),
-            },
-            None => &mut self.raw_items.items,
-        }
-        .push(RawItem { attrs, kind })
-    }
-
-    fn parse_attrs(&self, item: &impl ast::AttrsOwner) -> Attrs {
-        Attrs::new(item, &self.hygiene)
-    }
-}
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index 05cd0297d..503099fb7 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -424,31 +424,6 @@ fn extern_crate_rename_2015_edition() {
 }
 
 #[test]
-fn import_across_source_roots() {
-    let map = def_map(
-        "
-        //- /main.rs crate:main deps:test_crate
-        use test_crate::a::b::C;
-
-        //- root /test_crate/
-
-        //- /test_crate/lib.rs crate:test_crate
-        pub mod a {
-            pub mod b {
-                pub struct C;
-            }
-        }
-
-        ",
-    );
-
-    assert_snapshot!(map, @r###"
-        ⋮crate
-        ⋮C: t v
-    "###);
-}
-
-#[test]
 fn reexport_across_crates() {
     let map = def_map(
         "
diff --git a/crates/ra_hir_def/src/nameres/tests/globs.rs b/crates/ra_hir_def/src/nameres/tests/globs.rs
index 2b12c0daa..7f3d7509c 100644
--- a/crates/ra_hir_def/src/nameres/tests/globs.rs
+++ b/crates/ra_hir_def/src/nameres/tests/globs.rs
@@ -229,3 +229,140 @@ fn glob_enum_group() {
     "###
     );
 }
+
+#[test]
+fn glob_shadowed_def() {
+    mark::check!(import_shadowed);
+    let map = def_map(
+        r###"
+        //- /lib.rs
+        mod foo;
+        mod bar;
+
+        use foo::*;
+        use bar::baz;
+
+        use baz::Bar;
+
+        //- /foo.rs
+        pub mod baz {
+            pub struct Foo;
+        }
+
+        //- /bar.rs
+        pub mod baz {
+            pub struct Bar;
+        }
+        "###,
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮bar: t
+        ⋮baz: t
+        ⋮foo: t
+        ⋮
+        ⋮crate::bar
+        ⋮baz: t
+        ⋮
+        ⋮crate::bar::baz
+        ⋮Bar: t v
+        ⋮
+        ⋮crate::foo
+        ⋮baz: t
+        ⋮
+        ⋮crate::foo::baz
+        ⋮Foo: t v
+    "###
+    );
+}
+
+#[test]
+fn glob_shadowed_def_reversed() {
+    let map = def_map(
+        r###"
+        //- /lib.rs
+        mod foo;
+        mod bar;
+
+        use bar::baz;
+        use foo::*;
+
+        use baz::Bar;
+
+        //- /foo.rs
+        pub mod baz {
+            pub struct Foo;
+        }
+
+        //- /bar.rs
+        pub mod baz {
+            pub struct Bar;
+        }
+        "###,
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮bar: t
+        ⋮baz: t
+        ⋮foo: t
+        ⋮
+        ⋮crate::bar
+        ⋮baz: t
+        ⋮
+        ⋮crate::bar::baz
+        ⋮Bar: t v
+        ⋮
+        ⋮crate::foo
+        ⋮baz: t
+        ⋮
+        ⋮crate::foo::baz
+        ⋮Foo: t v
+    "###
+    );
+}
+
+#[test]
+fn glob_shadowed_def_dependencies() {
+    let map = def_map(
+        r###"
+        //- /lib.rs
+        mod a { pub mod foo { pub struct X; } }
+        mod b { pub use super::a::foo; }
+        mod c { pub mod foo { pub struct Y; } }
+        mod d {
+            use super::c::foo;
+            use super::b::*;
+            use foo::Y;
+        }
+        "###,
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮a: t
+        ⋮b: t
+        ⋮c: t
+        ⋮d: t
+        ⋮
+        ⋮crate::d
+        ⋮Y: t v
+        ⋮foo: t
+        ⋮
+        ⋮crate::c
+        ⋮foo: t
+        ⋮
+        ⋮crate::c::foo
+        ⋮Y: t v
+        ⋮
+        ⋮crate::b
+        ⋮foo: t
+        ⋮
+        ⋮crate::a
+        ⋮foo: t
+        ⋮
+        ⋮crate::a::foo
+        ⋮X: t v
+    "###
+    );
+}
diff --git a/crates/ra_hir_def/src/nameres/tests/incremental.rs b/crates/ra_hir_def/src/nameres/tests/incremental.rs
index 87165ac33..0c288a108 100644
--- a/crates/ra_hir_def/src/nameres/tests/incremental.rs
+++ b/crates/ra_hir_def/src/nameres/tests/incremental.rs
@@ -58,44 +58,6 @@ fn typing_inside_a_function_should_not_invalidate_def_map() {
 }
 
 #[test]
-fn adding_inner_items_should_not_invalidate_def_map() {
-    check_def_map_is_not_recomputed(
-        r"
-        //- /lib.rs
-        struct S { a: i32}
-        enum E { A }
-        trait T {
-            fn a() {}
-        }
-        mod foo;<|>
-        impl S {
-            fn a() {}
-        }
-        use crate::foo::bar::Baz;
-        //- /foo/mod.rs
-        pub mod bar;
-
-        //- /foo/bar.rs
-        pub struct Baz;
-        ",
-        r"
-        struct S { a: i32, b: () }
-        enum E { A, B }
-        trait T {
-            fn a() {}
-            fn b() {}
-        }
-        mod foo;<|>
-        impl S {
-            fn a() {}
-            fn b() {}
-        }
-        use crate::foo::bar::Baz;
-        ",
-    );
-}
-
-#[test]
 fn typing_inside_a_macro_should_not_invalidate_def_map() {
     let (mut db, pos) = TestDB::with_position(
         r"
diff --git a/crates/ra_hir_def/src/nameres/tests/macros.rs b/crates/ra_hir_def/src/nameres/tests/macros.rs
index 84480d9f6..c52341a07 100644
--- a/crates/ra_hir_def/src/nameres/tests/macros.rs
+++ b/crates/ra_hir_def/src/nameres/tests/macros.rs
@@ -660,3 +660,27 @@ fn expand_multiple_derive() {
     );
     assert_eq!(map.modules[map.root].scope.impls().len(), 2);
 }
+
+#[test]
+fn macro_expansion_overflow() {
+    mark::check!(macro_expansion_overflow);
+    compute_crate_def_map(
+        "
+macro_rules! a {
+    ($e:expr; $($t:tt)*) => {
+        b!($($t)*);
+    };
+    () => {};
+}
+
+macro_rules! b {
+    (static = $e:expr; $($t:tt)*) => {
+        a!($e; $($t)*);
+    };
+    () => {};
+}
+
+b! { static = #[] (); }
+",
+    );
+}
diff --git a/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs b/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
index b43b294ca..753684201 100644
--- a/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
@@ -20,8 +20,11 @@ fn name_res_works_for_broken_modules() {
         ",
     );
     assert_snapshot!(map, @r###"
-        ⋮crate
-        ⋮Baz: _
+crate
+Baz: _
+foo: t
+
+crate::foo
     "###);
 }
 
@@ -332,6 +335,22 @@ fn module_resolution_relative_path_2() {
 }
 
 #[test]
+fn module_resolution_relative_path_outside_root() {
+    let map = def_map(
+        r###"
+        //- /main.rs
+
+        #[path="../../../../../outside.rs"]
+        mod foo;
+        "###,
+    );
+
+    assert_snapshot!(map, @r###"
+        ⋮crate
+    "###);
+}
+
+#[test]
 fn module_resolution_explicit_path_mod_rs_2() {
     let map = def_map(
         r###"
@@ -719,10 +738,7 @@ fn unresolved_module_diagnostics() {
                         ),
                     ),
                 ),
-                value: FileAstId {
-                    raw: Idx::<SyntaxNodePtr>(1),
-                    _ty: PhantomData,
-                },
+                value: FileAstId::<ra_syntax::ast::generated::nodes::Module>(1),
             },
             candidate: "bar.rs",
         },
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index e84efe2ab..190d6d98d 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -76,6 +76,19 @@ impl ModPath {
         }
     }
 
+    /// Returns the number of segments in the path (counting special segments like `$crate` and
+    /// `super`).
+    pub fn len(&self) -> usize {
+        self.segments.len()
+            + match self.kind {
+                PathKind::Plain => 0,
+                PathKind::Super(i) => i as usize,
+                PathKind::Crate => 1,
+                PathKind::Abs => 0,
+                PathKind::DollarCrate(_) => 1,
+            }
+    }
+
     pub fn is_ident(&self) -> bool {
         self.kind == PathKind::Plain && self.segments.len() == 1
     }
@@ -141,7 +154,7 @@ pub enum GenericArg {
 
 impl Path {
     /// Converts an `ast::Path` to `Path`. Works with use trees.
-    /// DEPRECATED: It does not handle `$crate` from macro call.
+    #[deprecated = "Doesn't handle hygiene, don't add new calls, remove old ones"]
     pub fn from_ast(path: ast::Path) -> Option<Path> {
         lower::lower_path(path, &Hygiene::new_unhygienic())
     }
@@ -273,7 +286,7 @@ impl From<Name> for ModPath {
 impl Display for ModPath {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut first_segment = true;
-        let mut add_segment = |s| {
+        let mut add_segment = |s| -> fmt::Result {
             if !first_segment {
                 f.write_str("::")?;
             }
@@ -310,16 +323,16 @@ pub use hir_expand::name as __name;
 
 #[macro_export]
 macro_rules! __known_path {
-    (std::iter::IntoIterator) => {};
-    (std::result::Result) => {};
-    (std::ops::Range) => {};
-    (std::ops::RangeFrom) => {};
-    (std::ops::RangeFull) => {};
-    (std::ops::RangeTo) => {};
-    (std::ops::RangeToInclusive) => {};
-    (std::ops::RangeInclusive) => {};
-    (std::future::Future) => {};
-    (std::ops::Try) => {};
+    (core::iter::IntoIterator) => {};
+    (core::result::Result) => {};
+    (core::ops::Range) => {};
+    (core::ops::RangeFrom) => {};
+    (core::ops::RangeFull) => {};
+    (core::ops::RangeTo) => {};
+    (core::ops::RangeToInclusive) => {};
+    (core::ops::RangeInclusive) => {};
+    (core::future::Future) => {};
+    (core::ops::Try) => {};
     ($path:path) => {
         compile_error!("Please register your known path in the path module")
     };
diff --git a/crates/ra_hir_def/src/per_ns.rs b/crates/ra_hir_def/src/per_ns.rs
index 6e435c8c1..74665c588 100644
--- a/crates/ra_hir_def/src/per_ns.rs
+++ b/crates/ra_hir_def/src/per_ns.rs
@@ -5,7 +5,7 @@
 
 use hir_expand::MacroDefId;
 
-use crate::{visibility::Visibility, ModuleDefId};
+use crate::{item_scope::ItemInNs, visibility::Visibility, ModuleDefId};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct PerNs {
@@ -84,4 +84,12 @@ impl PerNs {
             macros: self.macros.or(other.macros),
         }
     }
+
+    pub fn iter_items(self) -> impl Iterator<Item = ItemInNs> {
+        self.types
+            .map(|it| ItemInNs::Types(it.0))
+            .into_iter()
+            .chain(self.values.map(|it| ItemInNs::Values(it.0)).into_iter())
+            .chain(self.macros.map(|it| ItemInNs::Macros(it.0)).into_iter())
+    }
 }
diff --git a/crates/ra_hir_def/src/resolver.rs b/crates/ra_hir_def/src/resolver.rs
index 15fdd9019..0bf51eb7b 100644
--- a/crates/ra_hir_def/src/resolver.rs
+++ b/crates/ra_hir_def/src/resolver.rs
@@ -511,11 +511,9 @@ impl Scope {
                     });
                 }
             }
-            Scope::LocalItemsScope(body) => {
-                body.item_scope.entries_without_primitives().for_each(|(name, def)| {
-                    f(name.clone(), ScopeDef::PerNs(def));
-                })
-            }
+            Scope::LocalItemsScope(body) => body.item_scope.entries().for_each(|(name, def)| {
+                f(name.clone(), ScopeDef::PerNs(def));
+            }),
             Scope::GenericParams { params, def } => {
                 for (local_id, param) in params.types.iter() {
                     if let Some(name) = &param.name {
diff --git a/crates/ra_hir_def/src/src.rs b/crates/ra_hir_def/src/src.rs
index 46e90da70..043b93fad 100644
--- a/crates/ra_hir_def/src/src.rs
+++ b/crates/ra_hir_def/src/src.rs
@@ -2,30 +2,37 @@
 
 use hir_expand::InFile;
 use ra_arena::map::ArenaMap;
-use ra_syntax::AstNode;
 
-use crate::{db::DefDatabase, AssocItemLoc, ItemLoc};
+use crate::{db::DefDatabase, item_tree::ItemTreeNode, AssocItemLoc, ItemLoc};
 
 pub trait HasSource {
     type Value;
     fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value>;
 }
 
-impl<N: AstNode> HasSource for AssocItemLoc<N> {
-    type Value = N;
+impl<N: ItemTreeNode> HasSource for AssocItemLoc<N> {
+    type Value = N::Source;
 
-    fn source(&self, db: &dyn DefDatabase) -> InFile<N> {
-        let node = self.ast_id.to_node(db.upcast());
-        InFile::new(self.ast_id.file_id, node)
+    fn source(&self, db: &dyn DefDatabase) -> InFile<N::Source> {
+        let tree = db.item_tree(self.id.file_id);
+        let ast_id_map = db.ast_id_map(self.id.file_id);
+        let root = db.parse_or_expand(self.id.file_id).unwrap();
+        let node = &tree[self.id.value];
+
+        InFile::new(self.id.file_id, ast_id_map.get(node.ast_id()).to_node(&root))
     }
 }
 
-impl<N: AstNode> HasSource for ItemLoc<N> {
-    type Value = N;
+impl<N: ItemTreeNode> HasSource for ItemLoc<N> {
+    type Value = N::Source;
+
+    fn source(&self, db: &dyn DefDatabase) -> InFile<N::Source> {
+        let tree = db.item_tree(self.id.file_id);
+        let ast_id_map = db.ast_id_map(self.id.file_id);
+        let root = db.parse_or_expand(self.id.file_id).unwrap();
+        let node = &tree[self.id.value];
 
-    fn source(&self, db: &dyn DefDatabase) -> InFile<N> {
-        let node = self.ast_id.to_node(db.upcast());
-        InFile::new(self.ast_id.file_id, node)
+        InFile::new(self.id.file_id, ast_id_map.get(node.ast_id()).to_node(&root))
     }
 }
 
diff --git a/crates/ra_hir_def/src/test_db.rs b/crates/ra_hir_def/src/test_db.rs
index eb83dee79..339f819b8 100644
--- a/crates/ra_hir_def/src/test_db.rs
+++ b/crates/ra_hir_def/src/test_db.rs
@@ -1,14 +1,13 @@
 //! Database used for testing `hir_def`.
 
 use std::{
-    panic,
+    fmt, panic,
     sync::{Arc, Mutex},
 };
 
 use hir_expand::db::AstDatabase;
-use ra_db::{
-    salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath, Upcast,
-};
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, Upcast};
+use rustc_hash::FxHashSet;
 
 use crate::db::DefDatabase;
 
@@ -19,10 +18,10 @@ use crate::db::DefDatabase;
     crate::db::InternDatabaseStorage,
     crate::db::DefDatabaseStorage
 )]
-#[derive(Debug, Default)]
+#[derive(Default)]
 pub struct TestDB {
-    runtime: salsa::Runtime<TestDB>,
-    events: Mutex<Option<Vec<salsa::Event<TestDB>>>>,
+    storage: salsa::Storage<TestDB>,
+    events: Mutex<Option<Vec<salsa::Event>>>,
 }
 
 impl Upcast<dyn AstDatabase> for TestDB {
@@ -38,44 +37,32 @@ impl Upcast<dyn DefDatabase> for TestDB {
 }
 
 impl salsa::Database for TestDB {
-    fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
-        &self.runtime
-    }
-    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
-        &mut self.runtime
-    }
-    fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
+    fn salsa_event(&self, event: salsa::Event) {
         let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
-            events.push(event());
+            events.push(event);
         }
     }
 }
 
+impl fmt::Debug for TestDB {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TestDB").finish()
+    }
+}
+
 impl panic::RefUnwindSafe for TestDB {}
 
 impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl TestDB {
@@ -91,7 +78,7 @@ impl TestDB {
         panic!("Can't find module for file")
     }
 
-    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event<TestDB>> {
+    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
         *self.events.lock().unwrap() = Some(Vec::new());
         f();
         self.events.lock().unwrap().take().unwrap()
@@ -105,7 +92,7 @@ impl TestDB {
                 // This pretty horrible, but `Debug` is the only way to inspect
                 // QueryDescriptor at the moment.
                 salsa::EventKind::WillExecute { database_key } => {
-                    Some(format!("{:?}", database_key))
+                    Some(format!("{:?}", database_key.debug(self)))
                 }
                 _ => None,
             })
diff --git a/crates/ra_hir_def/src/type_ref.rs b/crates/ra_hir_def/src/type_ref.rs
index 86a77b704..e90b2a0b9 100644
--- a/crates/ra_hir_def/src/type_ref.rs
+++ b/crates/ra_hir_def/src/type_ref.rs
@@ -63,7 +63,7 @@ pub enum TypeRef {
     Array(Box<TypeRef> /*, Expr*/),
     Slice(Box<TypeRef>),
     /// A fn pointer. Last element of the vector is the return type.
-    Fn(Vec<TypeRef>),
+    Fn(Vec<TypeRef>, bool /*varargs*/),
     // For
     ImplTrait(Vec<TypeBound>),
     DynTrait(Vec<TypeBound>),
@@ -118,7 +118,12 @@ impl TypeRef {
                     .and_then(|rt| rt.type_ref())
                     .map(|it| TypeRef::from_ast(ctx, it))
                     .unwrap_or_else(|| TypeRef::Tuple(Vec::new()));
+                let mut is_varargs = false;
                 let mut params = if let Some(pl) = inner.param_list() {
+                    if let Some(param) = pl.params().last() {
+                        is_varargs = param.dotdotdot_token().is_some();
+                    }
+
                     pl.params()
                         .map(|p| p.ascribed_type())
                         .map(|it| TypeRef::from_ast_opt(&ctx, it))
@@ -127,7 +132,7 @@ impl TypeRef {
                     Vec::new()
                 };
                 params.push(ret_ty);
-                TypeRef::Fn(params)
+                TypeRef::Fn(params, is_varargs)
             }
             // for types are close enough for our purposes to the inner type for now...
             ast::TypeRef::ForType(inner) => TypeRef::from_ast_opt(&ctx, inner.type_ref()),
@@ -158,7 +163,9 @@ impl TypeRef {
         fn go(type_ref: &TypeRef, f: &mut impl FnMut(&TypeRef)) {
             f(type_ref);
             match type_ref {
-                TypeRef::Fn(types) | TypeRef::Tuple(types) => types.iter().for_each(|t| go(t, f)),
+                TypeRef::Fn(types, _) | TypeRef::Tuple(types) => {
+                    types.iter().for_each(|t| go(t, f))
+                }
                 TypeRef::RawPtr(type_ref, _)
                 | TypeRef::Reference(type_ref, _)
                 | TypeRef::Array(type_ref)
diff --git a/crates/ra_hir_def/src/visibility.rs b/crates/ra_hir_def/src/visibility.rs
index 1482d3be0..8136cb50c 100644
--- a/crates/ra_hir_def/src/visibility.rs
+++ b/crates/ra_hir_def/src/visibility.rs
@@ -6,7 +6,7 @@ use ra_syntax::ast;
 use crate::{
     db::DefDatabase,
     path::{ModPath, PathKind},
-    AssocContainerId, ModuleId,
+    ModuleId,
 };
 
 /// Visibility of an item, not yet resolved.
@@ -25,25 +25,6 @@ impl RawVisibility {
         RawVisibility::Module(path)
     }
 
-    pub(crate) fn default_for_container(container_id: AssocContainerId) -> Self {
-        match container_id {
-            AssocContainerId::TraitId(_) => RawVisibility::Public,
-            _ => RawVisibility::private(),
-        }
-    }
-
-    pub(crate) fn from_ast_with_default(
-        db: &dyn DefDatabase,
-        default: RawVisibility,
-        node: InFile<Option<ast::Visibility>>,
-    ) -> RawVisibility {
-        Self::from_ast_with_hygiene_and_default(
-            node.value,
-            default,
-            &Hygiene::new(db.upcast(), node.file_id),
-        )
-    }
-
     pub(crate) fn from_ast(
         db: &dyn DefDatabase,
         node: InFile<Option<ast::Visibility>>,
diff --git a/crates/ra_hir_expand/Cargo.toml b/crates/ra_hir_expand/Cargo.toml
index 2cd522766..6da0e2a16 100644
--- a/crates/ra_hir_expand/Cargo.toml
+++ b/crates/ra_hir_expand/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_hir_expand"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -10,6 +11,7 @@ doctest = false
 [dependencies]
 log = "0.4.8"
 either = "1.5.3"
+rustc-hash = "1.0.0"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_expand/src/ast_id_map.rs b/crates/ra_hir_expand/src/ast_id_map.rs
index d19569245..f4d31526a 100644
--- a/crates/ra_hir_expand/src/ast_id_map.rs
+++ b/crates/ra_hir_expand/src/ast_id_map.rs
@@ -6,6 +6,8 @@
 //! changes.
 
 use std::{
+    any::type_name,
+    fmt,
     hash::{Hash, Hasher},
     marker::PhantomData,
 };
@@ -14,7 +16,6 @@ use ra_arena::{Arena, Idx};
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr};
 
 /// `AstId` points to an AST node in a specific file.
-#[derive(Debug)]
 pub struct FileAstId<N: AstNode> {
     raw: ErasedFileAstId,
     _ty: PhantomData<fn() -> N>,
@@ -39,11 +40,17 @@ impl<N: AstNode> Hash for FileAstId<N> {
     }
 }
 
+impl<N: AstNode> fmt::Debug for FileAstId<N> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "FileAstId::<{}>({})", type_name::<N>(), self.raw.into_raw())
+    }
+}
+
 impl<N: AstNode> FileAstId<N> {
     // Can't make this a From implementation because of coherence
     pub fn upcast<M: AstNode>(self) -> FileAstId<M>
     where
-        M: From<N>,
+        N: Into<M>,
     {
         FileAstId { raw: self.raw, _ty: PhantomData }
     }
@@ -89,7 +96,7 @@ impl AstIdMap {
         }
     }
 
-    pub(crate) fn get<N: AstNode>(&self, id: FileAstId<N>) -> AstPtr<N> {
+    pub fn get<N: AstNode>(&self, id: FileAstId<N>) -> AstPtr<N> {
         self.arena[id.raw].clone().cast::<N>().unwrap()
     }
 
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
index 1dc9cac66..f2d664863 100644
--- a/crates/ra_hir_expand/src/builtin_derive.rs
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -8,8 +8,7 @@ use ra_syntax::{
     match_ast,
 };
 
-use crate::db::AstDatabase;
-use crate::{name, quote, LazyMacroId, MacroCallId, MacroDefId, MacroDefKind};
+use crate::{db::AstDatabase, name, quote, LazyMacroId, MacroDefId, MacroDefKind};
 
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
@@ -156,23 +155,13 @@ fn expand_simple_derive(
 fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
     // FIXME: make hygiene works for builtin derive macro
     // such that $crate can be used here.
-
-    let m: MacroCallId = id.into();
-    let file_id = m.as_file().original_file(db);
     let cg = db.crate_graph();
-    let krates = db.relevant_crates(file_id);
-    let krate = match krates.get(0) {
-        Some(krate) => krate,
-        None => {
-            let tt = quote! { core };
-            return tt.token_trees[0].clone();
-        }
-    };
+    let krate = db.lookup_intern_macro(id).krate;
 
     // XXX
     //  All crates except core itself should have a dependency on core,
     //  We detect `core` by seeing whether it doesn't have such a dependency.
-    let tt = if cg[*krate].dependencies.iter().any(|dep| dep.name == "core") {
+    let tt = if cg[krate].dependencies.iter().any(|dep| &*dep.name == "core") {
         quote! { core }
     } else {
         quote! { crate }
@@ -264,10 +253,12 @@ fn partial_ord_expand(
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
     use name::{known, Name};
-    use ra_db::{fixture::WithFixture, SourceDatabase};
+    use ra_db::{fixture::WithFixture, CrateId, SourceDatabase};
+
+    use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
+
+    use super::*;
 
     fn expand_builtin_derive(s: &str, name: Name) -> String {
         let def = find_builtin_derive(&name).unwrap();
@@ -291,7 +282,11 @@ mod tests {
 
         let attr_id = AstId::new(file_id.into(), ast_id_map.ast_id(&items[0]));
 
-        let loc = MacroCallLoc { def, kind: MacroCallKind::Attr(attr_id, name.to_string()) };
+        let loc = MacroCallLoc {
+            def,
+            krate: CrateId(0),
+            kind: MacroCallKind::Attr(attr_id, name.to_string()),
+        };
 
         let id: MacroCallId = db.intern_macro(loc).into();
         let parsed = db.parse_or_expand(id.as_file()).unwrap();
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index 3bce8f673..9f50569dc 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -1,15 +1,14 @@
 //! Builtin macro
-use crate::db::AstDatabase;
 use crate::{
-    ast::{self, AstToken, HasStringValue},
-    name, AstId, CrateId, MacroDefId, MacroDefKind, TextSize,
+    db::AstDatabase, name, quote, AstId, CrateId, EagerMacroId, LazyMacroId, MacroCallId,
+    MacroDefId, MacroDefKind, TextSize,
 };
 
-use crate::{quote, EagerMacroId, LazyMacroId, MacroCallId};
 use either::Either;
 use mbe::parse_to_token_tree;
-use ra_db::{FileId, RelativePath};
+use ra_db::FileId;
 use ra_parser::FragmentKind;
+use ra_syntax::ast::{self, AstToken, HasStringValue};
 
 macro_rules! register_builtin {
     ( LAZY: $(($name:ident, $kind: ident) => $expand:ident),* , EAGER: $(($e_name:ident, $e_kind: ident) => $e_expand:ident),*  ) => {
@@ -100,6 +99,8 @@ register_builtin! {
     EAGER:
     (concat, Concat) => concat_expand,
     (include, Include) => include_expand,
+    (include_bytes, IncludeBytes) => include_bytes_expand,
+    (include_str, IncludeStr) => include_str_expand,
     (env, Env) => env_expand,
     (option_env, OptionEnv) => option_env_expand
 }
@@ -271,7 +272,7 @@ fn format_args_expand(
 fn unquote_str(lit: &tt::Literal) -> Option<String> {
     let lit = ast::make::tokens::literal(&lit.to_string());
     let token = ast::String::cast(lit)?;
-    token.value()
+    token.value().map(|it| it.into_owned())
 }
 
 fn concat_expand(
@@ -293,21 +294,20 @@ fn concat_expand(
     Ok((quote!(#text), FragmentKind::Expr))
 }
 
-fn relative_file(db: &dyn AstDatabase, call_id: MacroCallId, path: &str) -> Option<FileId> {
+fn relative_file(
+    db: &dyn AstDatabase,
+    call_id: MacroCallId,
+    path: &str,
+    allow_recursion: bool,
+) -> Option<FileId> {
     let call_site = call_id.as_file().original_file(db);
-
-    // Handle trivial case
-    if let Some(res) = db.resolve_relative_path(call_site, &RelativePath::new(&path)) {
-        // Prevent include itself
-        return if res == call_site { None } else { Some(res) };
+    let res = db.resolve_path(call_site, path)?;
+    // Prevent include itself
+    if res == call_site && !allow_recursion {
+        None
+    } else {
+        Some(res)
     }
-
-    // Extern paths ?
-    let krate = *db.relevant_crates(call_site).get(0)?;
-    let (extern_source_id, relative_file) =
-        db.crate_graph()[krate].extern_source.extern_path(path)?;
-
-    db.resolve_extern_path(extern_source_id, &relative_file)
 }
 
 fn parse_string(tt: &tt::Subtree) -> Result<String, mbe::ExpandError> {
@@ -326,8 +326,8 @@ fn include_expand(
     tt: &tt::Subtree,
 ) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
     let path = parse_string(tt)?;
-    let file_id =
-        relative_file(db, arg_id.into(), &path).ok_or_else(|| mbe::ExpandError::ConversionError)?;
+    let file_id = relative_file(db, arg_id.into(), &path, false)
+        .ok_or_else(|| mbe::ExpandError::ConversionError)?;
 
     // FIXME:
     // Handle include as expression
@@ -338,11 +338,50 @@ fn include_expand(
     Ok((res, FragmentKind::Items))
 }
 
-fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Option<String> {
-    let call_id: MacroCallId = arg_id.into();
-    let original_file = call_id.as_file().original_file(db);
+fn include_bytes_expand(
+    _db: &dyn AstDatabase,
+    _arg_id: EagerMacroId,
+    tt: &tt::Subtree,
+) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
+    let _path = parse_string(tt)?;
+
+    // FIXME: actually read the file here if the user asked for macro expansion
+    let res = tt::Subtree {
+        delimiter: None,
+        token_trees: vec![tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal {
+            text: r#"b"""#.into(),
+            id: tt::TokenId::unspecified(),
+        }))],
+    };
+    Ok((res, FragmentKind::Expr))
+}
+
+fn include_str_expand(
+    db: &dyn AstDatabase,
+    arg_id: EagerMacroId,
+    tt: &tt::Subtree,
+) -> Result<(tt::Subtree, FragmentKind), mbe::ExpandError> {
+    let path = parse_string(tt)?;
+
+    // FIXME: we're not able to read excluded files (which is most of them because
+    // it's unusual to `include_str!` a Rust file), but we can return an empty string.
+    // Ideally, we'd be able to offer a precise expansion if the user asks for macro
+    // expansion.
+    let file_id = match relative_file(db, arg_id.into(), &path, true) {
+        Some(file_id) => file_id,
+        None => {
+            return Ok((quote!(""), FragmentKind::Expr));
+        }
+    };
+
+    let text = db.file_text(file_id);
+    let text = &*text;
 
-    let krate = *db.relevant_crates(original_file).get(0)?;
+    Ok((quote!(#text), FragmentKind::Expr))
+}
+
+fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Option<String> {
+    let krate = db.lookup_intern_eager_expansion(arg_id).krate;
     db.crate_graph()[krate].env.get(key)
 }
 
@@ -401,6 +440,7 @@ mod tests {
 
         let expander = find_by_name(&macro_calls[0].name().unwrap().as_name()).unwrap();
 
+        let krate = CrateId(0);
         let file_id = match expander {
             Either::Left(expander) => {
                 // the first one should be a macro_rules
@@ -413,6 +453,7 @@ mod tests {
 
                 let loc = MacroCallLoc {
                     def,
+                    krate,
                     kind: MacroCallKind::FnLike(AstId::new(
                         file_id.into(),
                         ast_id_map.ast_id(&macro_calls[1]),
@@ -425,7 +466,7 @@ mod tests {
             Either::Right(expander) => {
                 // the first one should be a macro_rules
                 let def = MacroDefId {
-                    krate: Some(CrateId(0)),
+                    krate: Some(krate),
                     ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
                     kind: MacroDefKind::BuiltInEager(expander),
                     local_inner: false,
@@ -439,6 +480,7 @@ mod tests {
                         def,
                         fragment: FragmentKind::Expr,
                         subtree: Arc::new(parsed_args.clone()),
+                        krate,
                         file_id: file_id.into(),
                     }
                 });
@@ -448,6 +490,7 @@ mod tests {
                     def,
                     fragment,
                     subtree: Arc::new(subtree),
+                    krate,
                     file_id: file_id.into(),
                 };
 
@@ -587,4 +630,20 @@ mod tests {
             r#"std::fmt::Arguments::new_v1(&[], &[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
         );
     }
+
+    #[test]
+    fn test_include_bytes_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! include_bytes {
+                ($file:expr) => {{ /* compiler built-in */ }};
+                ($file:expr,) => {{ /* compiler built-in */ }};
+            }
+            include_bytes("foo");
+            "#,
+        );
+
+        assert_eq!(expanded, r#"b"""#);
+    }
 }
diff --git a/crates/ra_hir_expand/src/diagnostics.rs b/crates/ra_hir_expand/src/diagnostics.rs
index 99209c6e8..545cff9bd 100644
--- a/crates/ra_hir_expand/src/diagnostics.rs
+++ b/crates/ra_hir_expand/src/diagnostics.rs
@@ -28,7 +28,7 @@ pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
 
 pub trait AstDiagnostic {
     type AST;
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST;
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST;
 }
 
 impl dyn Diagnostic {
diff --git a/crates/ra_hir_expand/src/eager.rs b/crates/ra_hir_expand/src/eager.rs
index 932f47c30..302d2b3e0 100644
--- a/crates/ra_hir_expand/src/eager.rs
+++ b/crates/ra_hir_expand/src/eager.rs
@@ -25,12 +25,14 @@ use crate::{
     EagerCallLoc, EagerMacroId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
 
+use ra_db::CrateId;
 use ra_parser::FragmentKind;
 use ra_syntax::{algo::SyntaxRewriter, SyntaxNode};
 use std::sync::Arc;
 
 pub fn expand_eager_macro(
     db: &dyn AstDatabase,
+    krate: CrateId,
     macro_call: InFile<ast::MacroCall>,
     def: MacroDefId,
     resolver: &dyn Fn(ast::Path) -> Option<MacroDefId>,
@@ -47,6 +49,7 @@ pub fn expand_eager_macro(
             def,
             fragment: FragmentKind::Expr,
             subtree: Arc::new(parsed_args.clone()),
+            krate,
             file_id: macro_call.file_id,
         }
     });
@@ -56,14 +59,20 @@ pub fn expand_eager_macro(
     let result = eager_macro_recur(
         db,
         InFile::new(arg_file_id.as_file(), parsed_args.syntax_node()),
+        krate,
         resolver,
     )?;
     let subtree = to_subtree(&result)?;
 
     if let MacroDefKind::BuiltInEager(eager) = def.kind {
         let (subtree, fragment) = eager.expand(db, arg_id, &subtree).ok()?;
-        let eager =
-            EagerCallLoc { def, fragment, subtree: Arc::new(subtree), file_id: macro_call.file_id };
+        let eager = EagerCallLoc {
+            def,
+            fragment,
+            subtree: Arc::new(subtree),
+            krate,
+            file_id: macro_call.file_id,
+        };
 
         Some(db.intern_eager_expansion(eager))
     } else {
@@ -81,11 +90,12 @@ fn lazy_expand(
     db: &dyn AstDatabase,
     def: &MacroDefId,
     macro_call: InFile<ast::MacroCall>,
+    krate: CrateId,
 ) -> Option<InFile<SyntaxNode>> {
     let ast_id = db.ast_id_map(macro_call.file_id).ast_id(&macro_call.value);
 
     let id: MacroCallId =
-        def.as_lazy_macro(db, MacroCallKind::FnLike(macro_call.with_value(ast_id))).into();
+        def.as_lazy_macro(db, krate, MacroCallKind::FnLike(macro_call.with_value(ast_id))).into();
 
     db.parse_or_expand(id.as_file()).map(|node| InFile::new(id.as_file(), node))
 }
@@ -93,6 +103,7 @@ fn lazy_expand(
 fn eager_macro_recur(
     db: &dyn AstDatabase,
     curr: InFile<SyntaxNode>,
+    krate: CrateId,
     macro_resolver: &dyn Fn(ast::Path) -> Option<MacroDefId>,
 ) -> Option<SyntaxNode> {
     let original = curr.value.clone();
@@ -105,18 +116,23 @@ fn eager_macro_recur(
         let def: MacroDefId = macro_resolver(child.path()?)?;
         let insert = match def.kind {
             MacroDefKind::BuiltInEager(_) => {
-                let id: MacroCallId =
-                    expand_eager_macro(db, curr.with_value(child.clone()), def, macro_resolver)?
-                        .into();
+                let id: MacroCallId = expand_eager_macro(
+                    db,
+                    krate,
+                    curr.with_value(child.clone()),
+                    def,
+                    macro_resolver,
+                )?
+                .into();
                 db.parse_or_expand(id.as_file())?
             }
             MacroDefKind::Declarative
             | MacroDefKind::BuiltIn(_)
             | MacroDefKind::BuiltInDerive(_)
             | MacroDefKind::CustomDerive(_) => {
-                let expanded = lazy_expand(db, &def, curr.with_value(child.clone()))?;
+                let expanded = lazy_expand(db, &def, curr.with_value(child.clone()), krate)?;
                 // replace macro inside
-                eager_macro_recur(db, expanded, macro_resolver)?
+                eager_macro_recur(db, expanded, krate, macro_resolver)?
             }
         };
 
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index f440c073b..1cf6c1ba9 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -88,6 +88,25 @@ impl HirFileId {
         }
     }
 
+    pub fn expansion_level(self, db: &dyn db::AstDatabase) -> u32 {
+        let mut level = 0;
+        let mut curr = self;
+        while let HirFileIdRepr::MacroFile(macro_file) = curr.0 {
+            level += 1;
+            curr = match macro_file.macro_call_id {
+                MacroCallId::LazyMacro(id) => {
+                    let loc = db.lookup_intern_macro(id);
+                    loc.kind.file_id()
+                }
+                MacroCallId::EagerMacro(id) => {
+                    let loc = db.lookup_intern_eager_expansion(id);
+                    loc.file_id
+                }
+            };
+        }
+        level
+    }
+
     /// If this is a macro call, returns the syntax node of the call.
     pub fn call_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
         match self.0 {
@@ -209,8 +228,13 @@ pub struct MacroDefId {
 }
 
 impl MacroDefId {
-    pub fn as_lazy_macro(self, db: &dyn db::AstDatabase, kind: MacroCallKind) -> LazyMacroId {
-        db.intern_macro(MacroCallLoc { def: self, kind })
+    pub fn as_lazy_macro(
+        self,
+        db: &dyn db::AstDatabase,
+        krate: CrateId,
+        kind: MacroCallKind,
+    ) -> LazyMacroId {
+        db.intern_macro(MacroCallLoc { def: self, krate, kind })
     }
 }
 
@@ -227,6 +251,7 @@ pub enum MacroDefKind {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub(crate) def: MacroDefId,
+    pub(crate) krate: CrateId,
     pub(crate) kind: MacroCallKind,
 }
 
@@ -274,6 +299,7 @@ pub struct EagerCallLoc {
     pub(crate) def: MacroDefId,
     pub(crate) fragment: FragmentKind,
     pub(crate) subtree: Arc<tt::Subtree>,
+    pub(crate) krate: CrateId,
     pub(crate) file_id: HirFileId,
 }
 
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index ea495cb11..969a2e5b8 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -117,7 +117,7 @@ impl AsName for ast::FieldKind {
 
 impl AsName for ra_db::Dependency {
     fn as_name(&self) -> Name {
-        Name::new_text(self.name.clone())
+        Name::new_text(SmolStr::new(&*self.name))
     }
 }
 
@@ -153,6 +153,7 @@ pub mod known {
         str,
         // Special names
         macro_rules,
+        doc,
         // Components of known path (value or mod name)
         std,
         core,
@@ -190,6 +191,8 @@ pub mod known {
         stringify,
         concat,
         include,
+        include_bytes,
+        include_str,
         format_args,
         format_args_nl,
         env,
diff --git a/crates/ra_hir_expand/src/test_db.rs b/crates/ra_hir_expand/src/test_db.rs
index c1fb762de..332fa556f 100644
--- a/crates/ra_hir_expand/src/test_db.rs
+++ b/crates/ra_hir_expand/src/test_db.rs
@@ -1,36 +1,35 @@
 //! Database used for testing `hir_expand`.
 
 use std::{
-    panic,
+    fmt, panic,
     sync::{Arc, Mutex},
 };
 
-use ra_db::{salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath};
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate};
+use rustc_hash::FxHashSet;
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
     ra_db::SourceDatabaseStorage,
     crate::db::AstDatabaseStorage
 )]
-#[derive(Debug, Default)]
+#[derive(Default)]
 pub struct TestDB {
-    runtime: salsa::Runtime<TestDB>,
-    events: Mutex<Option<Vec<salsa::Event<TestDB>>>>,
+    storage: salsa::Storage<TestDB>,
+    events: Mutex<Option<Vec<salsa::Event>>>,
 }
 
-impl salsa::Database for TestDB {
-    fn salsa_runtime(&self) -> &salsa::Runtime<Self> {
-        &self.runtime
-    }
-
-    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
-        &mut self.runtime
+impl fmt::Debug for TestDB {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TestDB").finish()
     }
+}
 
-    fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
+impl salsa::Database for TestDB {
+    fn salsa_event(&self, event: salsa::Event) {
         let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
-            events.push(event());
+            events.push(event);
         }
     }
 }
@@ -41,21 +40,10 @@ impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        anchor: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(anchor, relative_path)
-    }
 }
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 4b8dcdc07..78f5e55bb 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_hir_ty"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -27,8 +28,14 @@ test_utils = { path = "../test_utils" }
 
 scoped-tls = "1"
 
-chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "329b7f3fdd2431ed6f6778cde53f22374c7d094c" }
-chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "329b7f3fdd2431ed6f6778cde53f22374c7d094c" }
+chalk-solve = { version = "0.17.0" }
+chalk-ir = { version = "0.17.0" }
+chalk-recursive = { version = "0.17.0" }
 
 [dev-dependencies]
 insta = "0.16.0"
+expect = { path = "../expect" }
+
+tracing = "0.1"
+tracing-subscriber = { version = "0.2", default-features = false, features = ["env-filter", "registry"] }
+tracing-tree = { version = "0.1.3" }
diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
deleted file mode 100644
index 3e6e1e333..000000000
--- a/crates/ra_hir_ty/src/_match.rs
+++ /dev/null
@@ -1,2085 +0,0 @@
-//! This module implements match statement exhaustiveness checking and usefulness checking
-//! for match arms.
-//!
-//! It is modeled on the rustc module `librustc_mir_build::hair::pattern::_match`, which
-//! contains very detailed documentation about the algorithms used here. I've duplicated
-//! most of that documentation below.
-//!
-//! This file includes the logic for exhaustiveness and usefulness checking for
-//! pattern-matching. Specifically, given a list of patterns for a type, we can
-//! tell whether:
-//! (a) the patterns cover every possible constructor for the type [exhaustiveness]
-//! (b) each pattern is necessary [usefulness]
-//!
-//! The algorithm implemented here is a modified version of the one described in:
-//! http://moscova.inria.fr/~maranget/papers/warn/index.html
-//! However, to save future implementors from reading the original paper, we
-//! summarise the algorithm here to hopefully save time and be a little clearer
-//! (without being so rigorous).
-//!
-//! The core of the algorithm revolves about a "usefulness" check. In particular, we
-//! are trying to compute a predicate `U(P, p)` where `P` is a list of patterns (we refer to this as
-//! a matrix). `U(P, p)` represents whether, given an existing list of patterns
-//! `P_1 ..= P_m`, adding a new pattern `p` will be "useful" (that is, cover previously-
-//! uncovered values of the type).
-//!
-//! If we have this predicate, then we can easily compute both exhaustiveness of an
-//! entire set of patterns and the individual usefulness of each one.
-//! (a) the set of patterns is exhaustive iff `U(P, _)` is false (i.e., adding a wildcard
-//! match doesn't increase the number of values we're matching)
-//! (b) a pattern `P_i` is not useful if `U(P[0..=(i-1), P_i)` is false (i.e., adding a
-//! pattern to those that have come before it doesn't increase the number of values
-//! we're matching).
-//!
-//! During the course of the algorithm, the rows of the matrix won't just be individual patterns,
-//! but rather partially-deconstructed patterns in the form of a list of patterns. The paper
-//! calls those pattern-vectors, and we will call them pattern-stacks. The same holds for the
-//! new pattern `p`.
-//!
-//! For example, say we have the following:
-//! ```
-//!     // x: (Option<bool>, Result<()>)
-//!     match x {
-//!         (Some(true), _) => {}
-//!         (None, Err(())) => {}
-//!         (None, Err(_)) => {}
-//!     }
-//! ```
-//! Here, the matrix `P` starts as:
-//! [
-//!     [(Some(true), _)],
-//!     [(None, Err(()))],
-//!     [(None, Err(_))],
-//! ]
-//! We can tell it's not exhaustive, because `U(P, _)` is true (we're not covering
-//! `[(Some(false), _)]`, for instance). In addition, row 3 is not useful, because
-//! all the values it covers are already covered by row 2.
-//!
-//! A list of patterns can be thought of as a stack, because we are mainly interested in the top of
-//! the stack at any given point, and we can pop or apply constructors to get new pattern-stacks.
-//! To match the paper, the top of the stack is at the beginning / on the left.
-//!
-//! There are two important operations on pattern-stacks necessary to understand the algorithm:
-//!     1. We can pop a given constructor off the top of a stack. This operation is called
-//!        `specialize`, and is denoted `S(c, p)` where `c` is a constructor (like `Some` or
-//!        `None`) and `p` a pattern-stack.
-//!        If the pattern on top of the stack can cover `c`, this removes the constructor and
-//!        pushes its arguments onto the stack. It also expands OR-patterns into distinct patterns.
-//!        Otherwise the pattern-stack is discarded.
-//!        This essentially filters those pattern-stacks whose top covers the constructor `c` and
-//!        discards the others.
-//!
-//!        For example, the first pattern above initially gives a stack `[(Some(true), _)]`. If we
-//!        pop the tuple constructor, we are left with `[Some(true), _]`, and if we then pop the
-//!        `Some` constructor we get `[true, _]`. If we had popped `None` instead, we would get
-//!        nothing back.
-//!
-//!        This returns zero or more new pattern-stacks, as follows. We look at the pattern `p_1`
-//!        on top of the stack, and we have four cases:
-//!             1.1. `p_1 = c(r_1, .., r_a)`, i.e. the top of the stack has constructor `c`. We
-//!                  push onto the stack the arguments of this constructor, and return the result:
-//!                     r_1, .., r_a, p_2, .., p_n
-//!             1.2. `p_1 = c'(r_1, .., r_a')` where `c ≠ c'`. We discard the current stack and
-//!                  return nothing.
-//!             1.3. `p_1 = _`. We push onto the stack as many wildcards as the constructor `c` has
-//!                  arguments (its arity), and return the resulting stack:
-//!                     _, .., _, p_2, .., p_n
-//!             1.4. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting
-//!                  stack:
-//!                     S(c, (r_1, p_2, .., p_n))
-//!                     S(c, (r_2, p_2, .., p_n))
-//!
-//!     2. We can pop a wildcard off the top of the stack. This is called `D(p)`, where `p` is
-//!        a pattern-stack.
-//!        This is used when we know there are missing constructor cases, but there might be
-//!        existing wildcard patterns, so to check the usefulness of the matrix, we have to check
-//!        all its *other* components.
-//!
-//!        It is computed as follows. We look at the pattern `p_1` on top of the stack,
-//!        and we have three cases:
-//!             1.1. `p_1 = c(r_1, .., r_a)`. We discard the current stack and return nothing.
-//!             1.2. `p_1 = _`. We return the rest of the stack:
-//!                     p_2, .., p_n
-//!             1.3. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting
-//!               stack.
-//!                     D((r_1, p_2, .., p_n))
-//!                     D((r_2, p_2, .., p_n))
-//!
-//!     Note that the OR-patterns are not always used directly in Rust, but are used to derive the
-//!     exhaustive integer matching rules, so they're written here for posterity.
-//!
-//! Both those operations extend straightforwardly to a list or pattern-stacks, i.e. a matrix, by
-//! working row-by-row. Popping a constructor ends up keeping only the matrix rows that start with
-//! the given constructor, and popping a wildcard keeps those rows that start with a wildcard.
-//!
-//!
-//! The algorithm for computing `U`
-//! -------------------------------
-//! The algorithm is inductive (on the number of columns: i.e., components of tuple patterns).
-//! That means we're going to check the components from left-to-right, so the algorithm
-//! operates principally on the first component of the matrix and new pattern-stack `p`.
-//! This algorithm is realised in the `is_useful` function.
-//!
-//! Base case. (`n = 0`, i.e., an empty tuple pattern)
-//!     - If `P` already contains an empty pattern (i.e., if the number of patterns `m > 0`),
-//!       then `U(P, p)` is false.
-//!     - Otherwise, `P` must be empty, so `U(P, p)` is true.
-//!
-//! Inductive step. (`n > 0`, i.e., whether there's at least one column
-//!                  [which may then be expanded into further columns later])
-//!     We're going to match on the top of the new pattern-stack, `p_1`.
-//!         - If `p_1 == c(r_1, .., r_a)`, i.e. we have a constructor pattern.
-//!           Then, the usefulness of `p_1` can be reduced to whether it is useful when
-//!           we ignore all the patterns in the first column of `P` that involve other constructors.
-//!           This is where `S(c, P)` comes in:
-//!           `U(P, p) := U(S(c, P), S(c, p))`
-//!           This special case is handled in `is_useful_specialized`.
-//!
-//!           For example, if `P` is:
-//!           [
-//!               [Some(true), _],
-//!               [None, 0],
-//!           ]
-//!           and `p` is [Some(false), 0], then we don't care about row 2 since we know `p` only
-//!           matches values that row 2 doesn't. For row 1 however, we need to dig into the
-//!           arguments of `Some` to know whether some new value is covered. So we compute
-//!           `U([[true, _]], [false, 0])`.
-//!
-//!         - If `p_1 == _`, then we look at the list of constructors that appear in the first
-//!               component of the rows of `P`:
-//!             + If there are some constructors that aren't present, then we might think that the
-//!               wildcard `_` is useful, since it covers those constructors that weren't covered
-//!               before.
-//!               That's almost correct, but only works if there were no wildcards in those first
-//!               components. So we need to check that `p` is useful with respect to the rows that
-//!               start with a wildcard, if there are any. This is where `D` comes in:
-//!               `U(P, p) := U(D(P), D(p))`
-//!
-//!               For example, if `P` is:
-//!               [
-//!                   [_, true, _],
-//!                   [None, false, 1],
-//!               ]
-//!               and `p` is [_, false, _], the `Some` constructor doesn't appear in `P`. So if we
-//!               only had row 2, we'd know that `p` is useful. However row 1 starts with a
-//!               wildcard, so we need to check whether `U([[true, _]], [false, 1])`.
-//!
-//!             + Otherwise, all possible constructors (for the relevant type) are present. In this
-//!               case we must check whether the wildcard pattern covers any unmatched value. For
-//!               that, we can think of the `_` pattern as a big OR-pattern that covers all
-//!               possible constructors. For `Option`, that would mean `_ = None | Some(_)` for
-//!               example. The wildcard pattern is useful in this case if it is useful when
-//!               specialized to one of the possible constructors. So we compute:
-//!               `U(P, p) := ∃(k ϵ constructors) U(S(k, P), S(k, p))`
-//!
-//!               For example, if `P` is:
-//!               [
-//!                   [Some(true), _],
-//!                   [None, false],
-//!               ]
-//!               and `p` is [_, false], both `None` and `Some` constructors appear in the first
-//!               components of `P`. We will therefore try popping both constructors in turn: we
-//!               compute U([[true, _]], [_, false]) for the `Some` constructor, and U([[false]],
-//!               [false]) for the `None` constructor. The first case returns true, so we know that
-//!               `p` is useful for `P`. Indeed, it matches `[Some(false), _]` that wasn't matched
-//!               before.
-//!
-//!         - If `p_1 == r_1 | r_2`, then the usefulness depends on each `r_i` separately:
-//!           `U(P, p) := U(P, (r_1, p_2, .., p_n))
-//!                    || U(P, (r_2, p_2, .., p_n))`
-use std::sync::Arc;
-
-use smallvec::{smallvec, SmallVec};
-
-use crate::{
-    db::HirDatabase,
-    expr::{Body, Expr, Literal, Pat, PatId},
-    ApplicationTy, InferenceResult, Ty, TypeCtor,
-};
-use hir_def::{adt::VariantData, AdtId, EnumVariantId, VariantId};
-use ra_arena::Idx;
-
-#[derive(Debug, Clone, Copy)]
-/// Either a pattern from the source code being analyzed, represented as
-/// as `PatId`, or a `Wild` pattern which is created as an intermediate
-/// step in the match checking algorithm and thus is not backed by a
-/// real `PatId`.
-///
-/// Note that it is totally valid for the `PatId` variant to contain
-/// a `PatId` which resolves to a `Wild` pattern, if that wild pattern
-/// exists in the source code being analyzed.
-enum PatIdOrWild {
-    PatId(PatId),
-    Wild,
-}
-
-impl PatIdOrWild {
-    fn as_pat(self, cx: &MatchCheckCtx) -> Pat {
-        match self {
-            PatIdOrWild::PatId(id) => cx.body.pats[id].clone(),
-            PatIdOrWild::Wild => Pat::Wild,
-        }
-    }
-
-    fn as_id(self) -> Option<PatId> {
-        match self {
-            PatIdOrWild::PatId(id) => Some(id),
-            PatIdOrWild::Wild => None,
-        }
-    }
-}
-
-impl From<PatId> for PatIdOrWild {
-    fn from(pat_id: PatId) -> Self {
-        Self::PatId(pat_id)
-    }
-}
-
-impl From<&PatId> for PatIdOrWild {
-    fn from(pat_id: &PatId) -> Self {
-        Self::PatId(*pat_id)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq)]
-pub enum MatchCheckErr {
-    NotImplemented,
-    MalformedMatchArm,
-    /// Used when type inference cannot resolve the type of
-    /// a pattern or expression.
-    Unknown,
-}
-
-/// The return type of `is_useful` is either an indication of usefulness
-/// of the match arm, or an error in the case the match statement
-/// is made up of types for which exhaustiveness checking is currently
-/// not completely implemented.
-///
-/// The `std::result::Result` type is used here rather than a custom enum
-/// to allow the use of `?`.
-pub type MatchCheckResult<T> = Result<T, MatchCheckErr>;
-
-#[derive(Debug)]
-/// A row in a Matrix.
-///
-/// This type is modeled from the struct of the same name in `rustc`.
-pub(crate) struct PatStack(PatStackInner);
-type PatStackInner = SmallVec<[PatIdOrWild; 2]>;
-
-impl PatStack {
-    pub(crate) fn from_pattern(pat_id: PatId) -> PatStack {
-        Self(smallvec!(pat_id.into()))
-    }
-
-    pub(crate) fn from_wild() -> PatStack {
-        Self(smallvec!(PatIdOrWild::Wild))
-    }
-
-    fn from_slice(slice: &[PatIdOrWild]) -> PatStack {
-        Self(SmallVec::from_slice(slice))
-    }
-
-    fn from_vec(v: PatStackInner) -> PatStack {
-        Self(v)
-    }
-
-    fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-
-    fn head(&self) -> PatIdOrWild {
-        self.0[0]
-    }
-
-    fn get_head(&self) -> Option<PatIdOrWild> {
-        self.0.first().copied()
-    }
-
-    fn to_tail(&self) -> PatStack {
-        Self::from_slice(&self.0[1..])
-    }
-
-    fn replace_head_with<I, T>(&self, pats: I) -> PatStack
-    where
-        I: Iterator<Item = T>,
-        T: Into<PatIdOrWild>,
-    {
-        let mut patterns: PatStackInner = smallvec![];
-        for pat in pats {
-            patterns.push(pat.into());
-        }
-        for pat in &self.0[1..] {
-            patterns.push(*pat);
-        }
-        PatStack::from_vec(patterns)
-    }
-
-    /// Computes `D(self)`.
-    ///
-    /// See the module docs and the associated documentation in rustc for details.
-    fn specialize_wildcard(&self, cx: &MatchCheckCtx) -> Option<PatStack> {
-        if matches!(self.head().as_pat(cx), Pat::Wild) {
-            Some(self.to_tail())
-        } else {
-            None
-        }
-    }
-
-    /// Computes `S(constructor, self)`.
-    ///
-    /// See the module docs and the associated documentation in rustc for details.
-    fn specialize_constructor(
-        &self,
-        cx: &MatchCheckCtx,
-        constructor: &Constructor,
-    ) -> MatchCheckResult<Option<PatStack>> {
-        let result = match (self.head().as_pat(cx), constructor) {
-            (Pat::Tuple { args: ref pat_ids, ellipsis }, Constructor::Tuple { arity: _ }) => {
-                if ellipsis.is_some() {
-                    // If there are ellipsis here, we should add the correct number of
-                    // Pat::Wild patterns to `pat_ids`. We should be able to use the
-                    // constructors arity for this, but at the time of writing we aren't
-                    // correctly calculating this arity when ellipsis are present.
-                    return Err(MatchCheckErr::NotImplemented);
-                }
-
-                Some(self.replace_head_with(pat_ids.iter()))
-            }
-            (Pat::Lit(lit_expr), Constructor::Bool(constructor_val)) => {
-                match cx.body.exprs[lit_expr] {
-                    Expr::Literal(Literal::Bool(pat_val)) if *constructor_val == pat_val => {
-                        Some(self.to_tail())
-                    }
-                    // it was a bool but the value doesn't match
-                    Expr::Literal(Literal::Bool(_)) => None,
-                    // perhaps this is actually unreachable given we have
-                    // already checked that these match arms have the appropriate type?
-                    _ => return Err(MatchCheckErr::NotImplemented),
-                }
-            }
-            (Pat::Wild, constructor) => Some(self.expand_wildcard(cx, constructor)?),
-            (Pat::Path(_), Constructor::Enum(constructor)) => {
-                // unit enum variants become `Pat::Path`
-                let pat_id = self.head().as_id().expect("we know this isn't a wild");
-                if !enum_variant_matches(cx, pat_id, *constructor) {
-                    None
-                } else {
-                    Some(self.to_tail())
-                }
-            }
-            (
-                Pat::TupleStruct { args: ref pat_ids, ellipsis, .. },
-                Constructor::Enum(enum_constructor),
-            ) => {
-                let pat_id = self.head().as_id().expect("we know this isn't a wild");
-                if !enum_variant_matches(cx, pat_id, *enum_constructor) {
-                    None
-                } else {
-                    let constructor_arity = constructor.arity(cx)?;
-                    if let Some(ellipsis_position) = ellipsis {
-                        // If there are ellipsis in the pattern, the ellipsis must take the place
-                        // of at least one sub-pattern, so `pat_ids` should be smaller than the
-                        // constructor arity.
-                        if pat_ids.len() < constructor_arity {
-                            let mut new_patterns: Vec<PatIdOrWild> = vec![];
-
-                            for pat_id in &pat_ids[0..ellipsis_position] {
-                                new_patterns.push((*pat_id).into());
-                            }
-
-                            for _ in 0..(constructor_arity - pat_ids.len()) {
-                                new_patterns.push(PatIdOrWild::Wild);
-                            }
-
-                            for pat_id in &pat_ids[ellipsis_position..pat_ids.len()] {
-                                new_patterns.push((*pat_id).into());
-                            }
-
-                            Some(self.replace_head_with(new_patterns.into_iter()))
-                        } else {
-                            return Err(MatchCheckErr::MalformedMatchArm);
-                        }
-                    } else {
-                        // If there is no ellipsis in the tuple pattern, the number
-                        // of patterns must equal the constructor arity.
-                        if pat_ids.len() == constructor_arity {
-                            Some(self.replace_head_with(pat_ids.into_iter()))
-                        } else {
-                            return Err(MatchCheckErr::MalformedMatchArm);
-                        }
-                    }
-                }
-            }
-            (Pat::Record { args: ref arg_patterns, .. }, Constructor::Enum(e)) => {
-                let pat_id = self.head().as_id().expect("we know this isn't a wild");
-                if !enum_variant_matches(cx, pat_id, *e) {
-                    None
-                } else {
-                    match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
-                        VariantData::Record(struct_field_arena) => {
-                            // Here we treat any missing fields in the record as the wild pattern, as
-                            // if the record has ellipsis. We want to do this here even if the
-                            // record does not contain ellipsis, because it allows us to continue
-                            // enforcing exhaustiveness for the rest of the match statement.
-                            //
-                            // Creating the diagnostic for the missing field in the pattern
-                            // should be done in a different diagnostic.
-                            let patterns = struct_field_arena.iter().map(|(_, struct_field)| {
-                                arg_patterns
-                                    .iter()
-                                    .find(|pat| pat.name == struct_field.name)
-                                    .map(|pat| PatIdOrWild::from(pat.pat))
-                                    .unwrap_or(PatIdOrWild::Wild)
-                            });
-
-                            Some(self.replace_head_with(patterns))
-                        }
-                        _ => return Err(MatchCheckErr::Unknown),
-                    }
-                }
-            }
-            (Pat::Or(_), _) => return Err(MatchCheckErr::NotImplemented),
-            (_, _) => return Err(MatchCheckErr::NotImplemented),
-        };
-
-        Ok(result)
-    }
-
-    /// A special case of `specialize_constructor` where the head of the pattern stack
-    /// is a Wild pattern.
-    ///
-    /// Replaces the Wild pattern at the head of the pattern stack with N Wild patterns
-    /// (N >= 0), where N is the arity of the given constructor.
-    fn expand_wildcard(
-        &self,
-        cx: &MatchCheckCtx,
-        constructor: &Constructor,
-    ) -> MatchCheckResult<PatStack> {
-        assert_eq!(
-            Pat::Wild,
-            self.head().as_pat(cx),
-            "expand_wildcard must only be called on PatStack with wild at head",
-        );
-
-        let mut patterns: PatStackInner = smallvec![];
-
-        for _ in 0..constructor.arity(cx)? {
-            patterns.push(PatIdOrWild::Wild);
-        }
-
-        for pat in &self.0[1..] {
-            patterns.push(*pat);
-        }
-
-        Ok(PatStack::from_vec(patterns))
-    }
-}
-
-#[derive(Debug)]
-/// A collection of PatStack.
-///
-/// This type is modeled from the struct of the same name in `rustc`.
-pub(crate) struct Matrix(Vec<PatStack>);
-
-impl Matrix {
-    pub(crate) fn empty() -> Self {
-        Self(vec![])
-    }
-
-    pub(crate) fn push(&mut self, cx: &MatchCheckCtx, row: PatStack) {
-        if let Some(Pat::Or(pat_ids)) = row.get_head().map(|pat_id| pat_id.as_pat(cx)) {
-            // Or patterns are expanded here
-            for pat_id in pat_ids {
-                self.0.push(PatStack::from_pattern(pat_id));
-            }
-        } else {
-            self.0.push(row);
-        }
-    }
-
-    fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-
-    fn heads(&self) -> Vec<PatIdOrWild> {
-        self.0.iter().map(|p| p.head()).collect()
-    }
-
-    /// Computes `D(self)` for each contained PatStack.
-    ///
-    /// See the module docs and the associated documentation in rustc for details.
-    fn specialize_wildcard(&self, cx: &MatchCheckCtx) -> Self {
-        Self::collect(cx, self.0.iter().filter_map(|r| r.specialize_wildcard(cx)))
-    }
-
-    /// Computes `S(constructor, self)` for each contained PatStack.
-    ///
-    /// See the module docs and the associated documentation in rustc for details.
-    fn specialize_constructor(
-        &self,
-        cx: &MatchCheckCtx,
-        constructor: &Constructor,
-    ) -> MatchCheckResult<Self> {
-        let mut new_matrix = Matrix::empty();
-        for pat in &self.0 {
-            if let Some(pat) = pat.specialize_constructor(cx, constructor)? {
-                new_matrix.push(cx, pat);
-            }
-        }
-
-        Ok(new_matrix)
-    }
-
-    fn collect<T: IntoIterator<Item = PatStack>>(cx: &MatchCheckCtx, iter: T) -> Self {
-        let mut matrix = Matrix::empty();
-
-        for pat in iter {
-            // using push ensures we expand or-patterns
-            matrix.push(cx, pat);
-        }
-
-        matrix
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-/// An indication of the usefulness of a given match arm, where
-/// usefulness is defined as matching some patterns which were
-/// not matched by an prior match arms.
-///
-/// We may eventually need an `Unknown` variant here.
-pub enum Usefulness {
-    Useful,
-    NotUseful,
-}
-
-pub struct MatchCheckCtx<'a> {
-    pub match_expr: Idx<Expr>,
-    pub body: Arc<Body>,
-    pub infer: Arc<InferenceResult>,
-    pub db: &'a dyn HirDatabase,
-}
-
-/// Given a set of patterns `matrix`, and pattern to consider `v`, determines
-/// whether `v` is useful. A pattern is useful if it covers cases which were
-/// not previously covered.
-///
-/// When calling this function externally (that is, not the recursive calls) it
-/// expected that you have already type checked the match arms. All patterns in
-/// matrix should be the same type as v, as well as they should all be the same
-/// type as the match expression.
-pub(crate) fn is_useful(
-    cx: &MatchCheckCtx,
-    matrix: &Matrix,
-    v: &PatStack,
-) -> MatchCheckResult<Usefulness> {
-    // Handle two special cases:
-    // - enum with no variants
-    // - `!` type
-    // In those cases, no match arm is useful.
-    match cx.infer[cx.match_expr].strip_references() {
-        Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(AdtId::EnumId(enum_id)), .. }) => {
-            if cx.db.enum_data(*enum_id).variants.is_empty() {
-                return Ok(Usefulness::NotUseful);
-            }
-        }
-        Ty::Apply(ApplicationTy { ctor: TypeCtor::Never, .. }) => {
-            return Ok(Usefulness::NotUseful);
-        }
-        _ => (),
-    }
-
-    if v.is_empty() {
-        let result = if matrix.is_empty() { Usefulness::Useful } else { Usefulness::NotUseful };
-
-        return Ok(result);
-    }
-
-    if let Pat::Or(pat_ids) = v.head().as_pat(cx) {
-        let mut found_unimplemented = false;
-        let any_useful = pat_ids.iter().any(|&pat_id| {
-            let v = PatStack::from_pattern(pat_id);
-
-            match is_useful(cx, matrix, &v) {
-                Ok(Usefulness::Useful) => true,
-                Ok(Usefulness::NotUseful) => false,
-                _ => {
-                    found_unimplemented = true;
-                    false
-                }
-            }
-        });
-
-        return if any_useful {
-            Ok(Usefulness::Useful)
-        } else if found_unimplemented {
-            Err(MatchCheckErr::NotImplemented)
-        } else {
-            Ok(Usefulness::NotUseful)
-        };
-    }
-
-    if let Some(constructor) = pat_constructor(cx, v.head())? {
-        let matrix = matrix.specialize_constructor(&cx, &constructor)?;
-        let v = v
-            .specialize_constructor(&cx, &constructor)?
-            .expect("we know this can't fail because we get the constructor from `v.head()` above");
-
-        is_useful(&cx, &matrix, &v)
-    } else {
-        // expanding wildcard
-        let mut used_constructors: Vec<Constructor> = vec![];
-        for pat in matrix.heads() {
-            if let Some(constructor) = pat_constructor(cx, pat)? {
-                used_constructors.push(constructor);
-            }
-        }
-
-        // We assume here that the first constructor is the "correct" type. Since we
-        // only care about the "type" of the constructor (i.e. if it is a bool we
-        // don't care about the value), this assumption should be valid as long as
-        // the match statement is well formed. We currently uphold this invariant by
-        // filtering match arms before calling `is_useful`, only passing in match arms
-        // whose type matches the type of the match expression.
-        match &used_constructors.first() {
-            Some(constructor) if all_constructors_covered(&cx, constructor, &used_constructors) => {
-                // If all constructors are covered, then we need to consider whether
-                // any values are covered by this wildcard.
-                //
-                // For example, with matrix '[[Some(true)], [None]]', all
-                // constructors are covered (`Some`/`None`), so we need
-                // to perform specialization to see that our wildcard will cover
-                // the `Some(false)` case.
-                //
-                // Here we create a constructor for each variant and then check
-                // usefulness after specializing for that constructor.
-                let mut found_unimplemented = false;
-                for constructor in constructor.all_constructors(cx) {
-                    let matrix = matrix.specialize_constructor(&cx, &constructor)?;
-                    let v = v.expand_wildcard(&cx, &constructor)?;
-
-                    match is_useful(&cx, &matrix, &v) {
-                        Ok(Usefulness::Useful) => return Ok(Usefulness::Useful),
-                        Ok(Usefulness::NotUseful) => continue,
-                        _ => found_unimplemented = true,
-                    };
-                }
-
-                if found_unimplemented {
-                    Err(MatchCheckErr::NotImplemented)
-                } else {
-                    Ok(Usefulness::NotUseful)
-                }
-            }
-            _ => {
-                // Either not all constructors are covered, or the only other arms
-                // are wildcards. Either way, this pattern is useful if it is useful
-                // when compared to those arms with wildcards.
-                let matrix = matrix.specialize_wildcard(&cx);
-                let v = v.to_tail();
-
-                is_useful(&cx, &matrix, &v)
-            }
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-/// Similar to TypeCtor, but includes additional information about the specific
-/// value being instantiated. For example, TypeCtor::Bool doesn't contain the
-/// boolean value.
-enum Constructor {
-    Bool(bool),
-    Tuple { arity: usize },
-    Enum(EnumVariantId),
-}
-
-impl Constructor {
-    fn arity(&self, cx: &MatchCheckCtx) -> MatchCheckResult<usize> {
-        let arity = match self {
-            Constructor::Bool(_) => 0,
-            Constructor::Tuple { arity } => *arity,
-            Constructor::Enum(e) => {
-                match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
-                    VariantData::Tuple(struct_field_data) => struct_field_data.len(),
-                    VariantData::Record(struct_field_data) => struct_field_data.len(),
-                    VariantData::Unit => 0,
-                }
-            }
-        };
-
-        Ok(arity)
-    }
-
-    fn all_constructors(&self, cx: &MatchCheckCtx) -> Vec<Constructor> {
-        match self {
-            Constructor::Bool(_) => vec![Constructor::Bool(true), Constructor::Bool(false)],
-            Constructor::Tuple { .. } => vec![*self],
-            Constructor::Enum(e) => cx
-                .db
-                .enum_data(e.parent)
-                .variants
-                .iter()
-                .map(|(local_id, _)| {
-                    Constructor::Enum(EnumVariantId { parent: e.parent, local_id })
-                })
-                .collect(),
-        }
-    }
-}
-
-/// Returns the constructor for the given pattern. Should only return None
-/// in the case of a Wild pattern.
-fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Option<Constructor>> {
-    let res = match pat.as_pat(cx) {
-        Pat::Wild => None,
-        // FIXME somehow create the Tuple constructor with the proper arity. If there are
-        // ellipsis, the arity is not equal to the number of patterns.
-        Pat::Tuple { args: pats, ellipsis } if ellipsis.is_none() => {
-            Some(Constructor::Tuple { arity: pats.len() })
-        }
-        Pat::Lit(lit_expr) => match cx.body.exprs[lit_expr] {
-            Expr::Literal(Literal::Bool(val)) => Some(Constructor::Bool(val)),
-            _ => return Err(MatchCheckErr::NotImplemented),
-        },
-        Pat::TupleStruct { .. } | Pat::Path(_) | Pat::Record { .. } => {
-            let pat_id = pat.as_id().expect("we already know this pattern is not a wild");
-            let variant_id =
-                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::Unknown)?;
-            match variant_id {
-                VariantId::EnumVariantId(enum_variant_id) => {
-                    Some(Constructor::Enum(enum_variant_id))
-                }
-                _ => return Err(MatchCheckErr::NotImplemented),
-            }
-        }
-        _ => return Err(MatchCheckErr::NotImplemented),
-    };
-
-    Ok(res)
-}
-
-fn all_constructors_covered(
-    cx: &MatchCheckCtx,
-    constructor: &Constructor,
-    used_constructors: &[Constructor],
-) -> bool {
-    match constructor {
-        Constructor::Tuple { arity } => {
-            used_constructors.iter().any(|constructor| match constructor {
-                Constructor::Tuple { arity: used_arity } => arity == used_arity,
-                _ => false,
-            })
-        }
-        Constructor::Bool(_) => {
-            if used_constructors.is_empty() {
-                return false;
-            }
-
-            let covers_true =
-                used_constructors.iter().any(|c| matches!(c, Constructor::Bool(true)));
-            let covers_false =
-                used_constructors.iter().any(|c| matches!(c, Constructor::Bool(false)));
-
-            covers_true && covers_false
-        }
-        Constructor::Enum(e) => cx.db.enum_data(e.parent).variants.iter().all(|(id, _)| {
-            for constructor in used_constructors {
-                if let Constructor::Enum(e) = constructor {
-                    if id == e.local_id {
-                        return true;
-                    }
-                }
-            }
-
-            false
-        }),
-    }
-}
-
-fn enum_variant_matches(cx: &MatchCheckCtx, pat_id: PatId, enum_variant_id: EnumVariantId) -> bool {
-    Some(enum_variant_id.into()) == cx.infer.variant_resolution_for_pat(pat_id)
-}
-
-#[cfg(test)]
-mod tests {
-    pub(super) use insta::assert_snapshot;
-    pub(super) use ra_db::fixture::WithFixture;
-
-    pub(super) use crate::{diagnostics::MissingMatchArms, test_db::TestDB};
-
-    pub(super) fn check_diagnostic_message(content: &str) -> String {
-        TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().0
-    }
-
-    pub(super) fn check_diagnostic(content: &str) {
-        let diagnostic_count =
-            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
-
-        assert_eq!(1, diagnostic_count, "no diagnostic reported");
-    }
-
-    pub(super) fn check_no_diagnostic(content: &str) {
-        let diagnostic_count =
-            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
-
-        assert_eq!(0, diagnostic_count, "expected no diagnostic, found one");
-    }
-
-    #[test]
-    fn empty_tuple_no_arms_diagnostic_message() {
-        let content = r"
-            fn test_fn() {
-                match () {
-                }
-            }
-        ";
-
-        assert_snapshot!(
-            check_diagnostic_message(content),
-            @"\"()\": Missing match arm\n"
-        );
-    }
-
-    #[test]
-    fn empty_tuple_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match () {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn empty_tuple_wild() {
-        let content = r"
-            fn test_fn() {
-                match () {
-                    _ => {}
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn empty_tuple_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match () {
-                    () => {}
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_empty_tuple_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match (()) {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_empty_tuple_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (()) {
-                    (()) => {}
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_two_empty_tuple_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match ((), ()) {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_two_empty_tuple_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match ((), ()) {
-                    ((), ()) => {}
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn bool_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match false {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn bool_missing_arm() {
-        let content = r"
-            fn test_fn() {
-                match false {
-                    true => {}
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn bool_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match false {
-                    true => {}
-                    false => {}
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_missing_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (true, true) => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_missing_arm() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (false, true) => {},
-                    (false, false) => {},
-                    (true, false) => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_wilds() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (false, _) => {},
-                    (true, false) => {},
-                    (_, true) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (true, true) => {},
-                    (true, false) => {},
-                    (false, true) => {},
-                    (false, false) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_binding_missing_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (true, _x) => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_binding_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, true) {
-                    (true, _x) => {},
-                    (false, true) => {},
-                    (false, false) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_ellipsis_at_end_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, true, false) {
-                    (false, ..) => {},
-                    (true, ..) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_ellipsis_at_beginning_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, true, false) {
-                    (.., false) => {},
-                    (.., true) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_ellipsis_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, true, false) {
-                    (..) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_tuple_and_bools_no_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, ((), false)) {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_tuple_and_bools_missing_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, ((), false)) {
-                    (true, ((), true)) => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_tuple_and_bools_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, ((), false)) {
-                    (true, ((), true)) => {},
-                    (true, ((), false)) => {},
-                    (false, ((), true)) => {},
-                    (false, ((), false)) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_tuple_and_bools_wildcard_missing_arms() {
-        let content = r"
-            fn test_fn() {
-                match (false, ((), false)) {
-                    (true, _) => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_tuple_and_bools_wildcard_no_diagnostic() {
-        let content = r"
-            fn test_fn() {
-                match (false, ((), false)) {
-                    (true, ((), true)) => {},
-                    (true, ((), false)) => {},
-                    (false, _) => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_no_arms() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match Either::A {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_missing_arms() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_ref_missing_arms() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match &Either::B {
-                    Either::A => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_ref_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match &Either::B {
-                    Either::A => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_containing_bool_no_arms() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_containing_bool_missing_arms() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true) => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_containing_bool_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true) => (),
-                    Either::A(false) => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_containing_bool_with_wild_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::B => (),
-                    _ => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_containing_bool_with_wild_2_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(_) => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_different_sizes_missing_arms() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B(bool, bool),
-            }
-            fn test_fn() {
-                match Either::A(false) {
-                    Either::A(_) => (),
-                    Either::B(false, _) => (),
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_different_sizes_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B(bool, bool),
-            }
-            fn test_fn() {
-                match Either::A(false) {
-                    Either::A(_) => (),
-                    Either::B(true, _) => (),
-                    Either::B(false, _) => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn or_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B(bool, bool),
-            }
-            fn test_fn() {
-                match Either::A(false) {
-                    Either::A(true) | Either::A(false) => (),
-                    Either::B(true, _) => (),
-                    Either::B(false, _) => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_enum_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool),
-                B(bool, bool),
-            }
-            enum Either2 {
-                C,
-                D,
-            }
-            fn test_fn() {
-                match (Either::A(false), Either2::C) {
-                    (Either::A(true), _) | (Either::A(false), _) => (),
-                    (Either::B(true, _), Either2::C) => (),
-                    (Either::B(false, _), Either2::C) => (),
-                    (Either::B(_, _), Either2::D) => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn mismatched_types() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            enum Either2 {
-                C,
-                D,
-            }
-            fn test_fn() {
-                match Either::A {
-                    Either2::C => (),
-                    Either2::D => (),
-                }
-            }
-        ";
-
-        // Match statements with arms that don't match the
-        // expression pattern do not fire this diagnostic.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn mismatched_types_with_different_arity() {
-        let content = r"
-            fn test_fn() {
-                match (true, false) {
-                    (true, false, true) => (),
-                    (true) => (),
-                }
-            }
-        ";
-
-        // Match statements with arms that don't match the
-        // expression pattern do not fire this diagnostic.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn malformed_match_arm_tuple_missing_pattern() {
-        let content = r"
-            fn test_fn() {
-                match (0) {
-                    () => (),
-                }
-            }
-        ";
-
-        // Match statements with arms that don't match the
-        // expression pattern do not fire this diagnostic.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn malformed_match_arm_tuple_enum_missing_pattern() {
-        let content = r"
-            enum Either {
-                A,
-                B(u32),
-            }
-            fn test_fn() {
-                match Either::A {
-                    Either::A => (),
-                    Either::B() => (),
-                }
-            }
-        ";
-
-        // We are testing to be sure we don't panic here when the match
-        // arm `Either::B` is missing its pattern.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_not_in_scope() {
-        let content = r"
-            fn test_fn() {
-                match Foo::Bar {
-                    Foo::Baz => (),
-                }
-            }
-        ";
-
-        // The enum is not in scope so we don't perform exhaustiveness
-        // checking, but we want to be sure we don't panic here (and
-        // we don't create a diagnostic).
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn expr_diverges() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match loop {} {
-                    Either::A => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn expr_loop_with_break() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match loop { break Foo::A } {
-                    Either::A => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn expr_partially_diverges() {
-        let content = r"
-            enum Either<T> {
-                A(T),
-                B,
-            }
-            fn foo() -> Either<!> {
-                Either::B
-            }
-            fn test_fn() -> u32 {
-                match foo() {
-                    Either::A(val) => val,
-                    Either::B => 0,
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_no_arms() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_missing_arms() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                    Either::A { foo: true } => (),
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                    Either::A { foo: true } => (),
-                    Either::A { foo: false } => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_missing_field_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::B;
-                match a {
-                    Either::A { } => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        // When `Either::A` is missing a struct member, we don't want
-        // to fire the missing match arm diagnostic. This should fire
-        // some other diagnostic.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_missing_field_missing_match_arm() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::B;
-                match a {
-                    Either::A { } => (),
-                }
-            }
-        ";
-
-        // Even though `Either::A` is missing fields, we still want to fire
-        // the missing arm diagnostic here, since we know `Either::B` is missing.
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_no_diagnostic_wild() {
-        let content = r"
-            enum Either {
-                A { foo: bool },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                    Either::A { foo: _ } => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_fields_out_of_order_missing_arm() {
-        let content = r"
-            enum Either {
-                A { foo: bool, bar: () },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                    Either::A { bar: (), foo: false } => (),
-                    Either::A { foo: true, bar: () } => (),
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_fields_out_of_order_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A { foo: bool, bar: () },
-                B,
-            }
-            fn test_fn() {
-                let a = Either::A { foo: true };
-                match a {
-                    Either::A { bar: (), foo: false } => (),
-                    Either::A { foo: true, bar: () } => (),
-                    Either::B => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_ellipsis_missing_arm() {
-        let content = r"
-             enum Either {
-                 A { foo: bool, bar: bool },
-                 B,
-             }
-             fn test_fn() {
-                 match Either::B {
-                     Either::A { foo: true, .. } => (),
-                     Either::B => (),
-                 }
-             }
-         ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_ellipsis_no_diagnostic() {
-        let content = r"
-             enum Either {
-                 A { foo: bool, bar: bool },
-                 B,
-             }
-             fn test_fn() {
-                 let a = Either::A { foo: true };
-                 match a {
-                     Either::A { foo: true, .. } => (),
-                     Either::A { foo: false, .. } => (),
-                     Either::B => (),
-                 }
-             }
-         ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_ellipsis_all_fields_missing_arm() {
-        let content = r"
-             enum Either {
-                 A { foo: bool, bar: bool },
-                 B,
-             }
-             fn test_fn() {
-                 let a = Either::B;
-                 match a {
-                     Either::A { .. } => (),
-                 }
-             }
-         ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_record_ellipsis_all_fields_no_diagnostic() {
-        let content = r"
-             enum Either {
-                 A { foo: bool, bar: bool },
-                 B,
-             }
-             fn test_fn() {
-                 let a = Either::B;
-                 match a {
-                     Either::A { .. } => (),
-                     Either::B => (),
-                 }
-             }
-         ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_tuple_partial_ellipsis_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool, bool, bool, bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true, .., true) => {},
-                    Either::A(true, .., false) => {},
-                    Either::A(false, .., true) => {},
-                    Either::A(false, .., false) => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_tuple_partial_ellipsis_2_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool, bool, bool, bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true, .., true) => {},
-                    Either::A(true, .., false) => {},
-                    Either::A(.., true) => {},
-                    Either::A(.., false) => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_tuple_partial_ellipsis_missing_arm() {
-        let content = r"
-            enum Either {
-                A(bool, bool, bool, bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true, .., true) => {},
-                    Either::A(true, .., false) => {},
-                    Either::A(false, .., false) => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_tuple_partial_ellipsis_2_missing_arm() {
-        let content = r"
-            enum Either {
-                A(bool, bool, bool, bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(true, .., true) => {},
-                    Either::A(true, .., false) => {},
-                    Either::A(.., true) => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_tuple_ellipsis_no_diagnostic() {
-        let content = r"
-            enum Either {
-                A(bool, bool, bool, bool),
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A(..) => {},
-                    Either::B => {},
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_never() {
-        let content = r"
-            enum Never {}
-
-            fn test_fn(never: Never) {
-                match never {}
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn type_never() {
-        let content = r"
-            fn test_fn(never: !) {
-                match never {}
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn enum_never_ref() {
-        let content = r"
-            enum Never {}
-
-            fn test_fn(never: &Never) {
-                match never {}
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn expr_diverges_missing_arm() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match loop {} {
-                    Either::A => (),
-                }
-            }
-        ";
-
-        check_no_diagnostic(content);
-    }
-}
-
-#[cfg(test)]
-mod false_negatives {
-    //! The implementation of match checking here is a work in progress. As we roll this out, we
-    //! prefer false negatives to false positives (ideally there would be no false positives). This
-    //! test module should document known false negatives. Eventually we will have a complete
-    //! implementation of match checking and this module will be empty.
-    //!
-    //! The reasons for documenting known false negatives:
-    //!
-    //!   1. It acts as a backlog of work that can be done to improve the behavior of the system.
-    //!   2. It ensures the code doesn't panic when handling these cases.
-
-    use super::tests::*;
-
-    #[test]
-    fn integers() {
-        let content = r"
-            fn test_fn() {
-                match 5 {
-                    10 => (),
-                    11..20 => (),
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We don't currently check integer exhaustiveness.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn internal_or() {
-        let content = r"
-            fn test_fn() {
-                enum Either {
-                    A(bool),
-                    B,
-                }
-                match Either::B {
-                    Either::A(true | false) => (),
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We do not currently handle patterns with internal `or`s.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn expr_loop_missing_arm() {
-        let content = r"
-            enum Either {
-                A,
-                B,
-            }
-            fn test_fn() {
-                match loop { break Foo::A } {
-                    Either::A => (),
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We currently infer the type of `loop { break Foo::A }` to `!`, which
-        // causes us to skip the diagnostic since `Either::A` doesn't type check
-        // with `!`.
-        check_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_ellipsis_at_end_missing_arm() {
-        let content = r"
-            fn test_fn() {
-                match (false, true, false) {
-                    (false, ..) => {},
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We don't currently handle tuple patterns with ellipsis.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() {
-        let content = r"
-            fn test_fn() {
-                match (false, true, false) {
-                    (.., false) => {},
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We don't currently handle tuple patterns with ellipsis.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
-    fn struct_missing_arm() {
-        let content = r"
-            struct Foo {
-                a: bool,
-            }
-            fn test_fn(f: Foo) {
-                match f {
-                    Foo { a: true } => {},
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We don't currently handle structs.
-        check_no_diagnostic(content);
-    }
-}
diff --git a/crates/ra_hir_ty/src/autoderef.rs b/crates/ra_hir_ty/src/autoderef.rs
index 1b0f84c5c..c727012c6 100644
--- a/crates/ra_hir_ty/src/autoderef.rs
+++ b/crates/ra_hir_ty/src/autoderef.rs
@@ -37,7 +37,7 @@ pub(crate) fn deref(
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
     if let Some(derefed) = ty.value.value.builtin_deref() {
-        Some(Canonical { value: derefed, num_vars: ty.value.num_vars })
+        Some(Canonical { value: derefed, kinds: ty.value.kinds.clone() })
     } else {
         deref_by_trait(db, krate, ty)
     }
@@ -68,8 +68,8 @@ fn deref_by_trait(
 
     // Check that the type implements Deref at all
     let trait_ref = TraitRef { trait_: deref_trait, substs: parameters.clone() };
-    let implements_goal = super::Canonical {
-        num_vars: ty.value.num_vars,
+    let implements_goal = Canonical {
+        kinds: ty.value.kinds.clone(),
         value: InEnvironment {
             value: Obligation::Trait(trait_ref),
             environment: ty.environment.clone(),
@@ -81,7 +81,7 @@ fn deref_by_trait(
 
     // Now do the assoc type projection
     let projection = super::traits::ProjectionPredicate {
-        ty: Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.num_vars)),
+        ty: Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.kinds.len())),
         projection_ty: super::ProjectionTy { associated_ty: target, parameters },
     };
 
@@ -89,7 +89,8 @@ fn deref_by_trait(
 
     let in_env = InEnvironment { value: obligation, environment: ty.environment };
 
-    let canonical = super::Canonical { num_vars: 1 + ty.value.num_vars, value: in_env };
+    let canonical =
+        Canonical::new(in_env, ty.value.kinds.iter().copied().chain(Some(super::TyKind::General)));
 
     let solution = db.trait_solve(krate, canonical)?;
 
@@ -110,7 +111,7 @@ fn deref_by_trait(
             // assumptions will be broken. We would need to properly introduce
             // new variables in that case
 
-            for i in 1..vars.0.num_vars {
+            for i in 1..vars.0.kinds.len() {
                 if vars.0.value[i - 1] != Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, i - 1))
                 {
                     warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.value, solution);
@@ -119,7 +120,7 @@ fn deref_by_trait(
             }
             Some(Canonical {
                 value: vars.0.value[vars.0.value.len() - 1].clone(),
-                num_vars: vars.0.num_vars,
+                kinds: vars.0.kinds.clone(),
             })
         }
         Solution::Ambig(_) => {
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 0a8bb24ac..c773adc67 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -3,23 +3,22 @@
 use std::sync::Arc;
 
 use hir_def::{
-    db::DefDatabase, DefWithBodyId, GenericDefId, ImplId, LocalFieldId, TraitId, TypeParamId,
-    VariantId,
+    db::DefDatabase, expr::ExprId, DefWithBodyId, FunctionId, GenericDefId, ImplId, LocalFieldId,
+    TypeParamId, VariantId,
 };
 use ra_arena::map::ArenaMap;
 use ra_db::{impl_intern_key, salsa, CrateId, Upcast};
 use ra_prof::profile;
 
 use crate::{
-    method_resolution::{CrateImplDefs, TyFingerprint},
-    traits::{chalk, AssocTyValue, Impl},
-    Binders, CallableDef, GenericPredicate, InferenceResult, PolyFnSig, Substs, TraitRef, Ty,
-    TyDefId, TypeCtor, ValueTyDefId,
+    method_resolution::{InherentImpls, TraitImpls},
+    traits::chalk,
+    Binders, CallableDefId, GenericPredicate, InferenceResult, OpaqueTyId, PolyFnSig,
+    ReturnTypeImplTraits, TraitRef, Ty, TyDefId, ValueTyDefId,
 };
 use hir_expand::name::Name;
 
 #[salsa::query_group(HirDatabaseStorage)]
-#[salsa::requires(salsa::Database)]
 pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     #[salsa::invoke(infer_wait)]
     #[salsa::transparent]
@@ -46,7 +45,13 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalFieldId, Binders<Ty>>>;
 
     #[salsa::invoke(crate::callable_item_sig)]
-    fn callable_item_signature(&self, def: CallableDef) -> PolyFnSig;
+    fn callable_item_signature(&self, def: CallableDefId) -> PolyFnSig;
+
+    #[salsa::invoke(crate::lower::return_type_impl_traits)]
+    fn return_type_impl_traits(
+        &self,
+        def: FunctionId,
+    ) -> Option<Arc<Binders<ReturnTypeImplTraits>>>;
 
     #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
     #[salsa::cycle(crate::lower::generic_predicates_for_param_recover)]
@@ -59,30 +64,26 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     fn generic_predicates(&self, def: GenericDefId) -> Arc<[Binders<GenericPredicate>]>;
 
     #[salsa::invoke(crate::lower::generic_defaults_query)]
-    fn generic_defaults(&self, def: GenericDefId) -> Substs;
+    fn generic_defaults(&self, def: GenericDefId) -> Arc<[Binders<Ty>]>;
 
-    #[salsa::invoke(crate::method_resolution::CrateImplDefs::impls_in_crate_query)]
-    fn impls_in_crate(&self, krate: CrateId) -> Arc<CrateImplDefs>;
+    #[salsa::invoke(InherentImpls::inherent_impls_in_crate_query)]
+    fn inherent_impls_in_crate(&self, krate: CrateId) -> Arc<InherentImpls>;
 
-    #[salsa::invoke(crate::traits::impls_for_trait_query)]
-    fn impls_for_trait(
-        &self,
-        krate: CrateId,
-        trait_: TraitId,
-        self_ty_fp: Option<TyFingerprint>,
-    ) -> Arc<[ImplId]>;
+    #[salsa::invoke(TraitImpls::trait_impls_in_crate_query)]
+    fn trait_impls_in_crate(&self, krate: CrateId) -> Arc<TraitImpls>;
+
+    #[salsa::invoke(TraitImpls::trait_impls_in_deps_query)]
+    fn trait_impls_in_deps(&self, krate: CrateId) -> Arc<TraitImpls>;
 
     // Interned IDs for Chalk integration
     #[salsa::interned]
-    fn intern_type_ctor(&self, type_ctor: TypeCtor) -> crate::TypeCtorId;
-    #[salsa::interned]
-    fn intern_callable_def(&self, callable_def: CallableDef) -> crate::CallableDefId;
+    fn intern_callable_def(&self, callable_def: CallableDefId) -> InternedCallableDefId;
     #[salsa::interned]
     fn intern_type_param_id(&self, param_id: TypeParamId) -> GlobalTypeParamId;
     #[salsa::interned]
-    fn intern_chalk_impl(&self, impl_: Impl) -> crate::traits::GlobalImplId;
+    fn intern_impl_trait_id(&self, id: OpaqueTyId) -> InternedOpaqueTyId;
     #[salsa::interned]
-    fn intern_assoc_ty_value(&self, assoc_ty_value: AssocTyValue) -> crate::traits::AssocTyValueId;
+    fn intern_closure(&self, id: (DefWithBodyId, ExprId)) -> ClosureId;
 
     #[salsa::invoke(chalk::associated_ty_data_query)]
     fn associated_ty_data(&self, id: chalk::AssocTypeId) -> Arc<chalk::AssociatedTyDatum>;
@@ -142,3 +143,17 @@ fn hir_database_is_object_safe() {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct GlobalTypeParamId(salsa::InternId);
 impl_intern_key!(GlobalTypeParamId);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct InternedOpaqueTyId(salsa::InternId);
+impl_intern_key!(InternedOpaqueTyId);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ClosureId(salsa::InternId);
+impl_intern_key!(ClosureId);
+
+/// This exists just for Chalk, because Chalk just has a single `FnDefId` where
+/// we have different IDs for struct and enum variant constructors.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
+pub struct InternedCallableDefId(salsa::InternId);
+impl_intern_key!(InternedCallableDefId);
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 2c7298714..d3ee9cf55 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -1,13 +1,30 @@
 //! FIXME: write short doc here
+mod expr;
+mod match_check;
+mod unsafe_check;
 
 use std::any::Any;
 
+use hir_def::DefWithBodyId;
+use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
 use hir_expand::{db::AstDatabase, name::Name, HirFileId, InFile};
+use ra_prof::profile;
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
 use stdx::format_to;
 
-pub use hir_def::{diagnostics::UnresolvedModule, expr::MatchArm};
-pub use hir_expand::diagnostics::{AstDiagnostic, Diagnostic, DiagnosticSink};
+use crate::db::HirDatabase;
+
+pub use crate::diagnostics::expr::{record_literal_missing_fields, record_pattern_missing_fields};
+
+pub fn validate_body(db: &dyn HirDatabase, owner: DefWithBodyId, sink: &mut DiagnosticSink<'_>) {
+    let _p = profile("validate_body");
+    let infer = db.infer(owner);
+    infer.add_diagnostics(db, owner, sink);
+    let mut validator = expr::ExprValidator::new(owner, infer.clone(), sink);
+    validator.validate_body(db);
+    let mut validator = unsafe_check::UnsafeValidator::new(owner, infer, sink);
+    validator.validate_body(db);
+}
 
 #[derive(Debug)]
 pub struct NoSuchField {
@@ -29,6 +46,16 @@ impl Diagnostic for NoSuchField {
     }
 }
 
+impl AstDiagnostic for NoSuchField {
+    type AST = ast::RecordField;
+
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.source().file_id).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::RecordField::cast(node).unwrap()
+    }
+}
+
 #[derive(Debug)]
 pub struct MissingFields {
     pub file: HirFileId,
@@ -55,7 +82,7 @@ impl Diagnostic for MissingFields {
 impl AstDiagnostic for MissingFields {
     type AST = ast::RecordFieldList;
 
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
         let root = db.parse_or_expand(self.source().file_id).unwrap();
         let node = self.source().value.to_node(&root);
         ast::RecordFieldList::cast(node).unwrap()
@@ -125,7 +152,7 @@ impl Diagnostic for MissingOkInTailExpr {
 impl AstDiagnostic for MissingOkInTailExpr {
     type AST = ast::Expr;
 
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
         let root = db.parse_or_expand(self.file).unwrap();
         let node = self.source().value.to_node(&root);
         ast::Expr::cast(node).unwrap()
@@ -153,9 +180,299 @@ impl Diagnostic for BreakOutsideOfLoop {
 impl AstDiagnostic for BreakOutsideOfLoop {
     type AST = ast::Expr;
 
-    fn ast(&self, db: &impl AstDatabase) -> Self::AST {
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
         let root = db.parse_or_expand(self.file).unwrap();
         let node = self.source().value.to_node(&root);
         ast::Expr::cast(node).unwrap()
     }
 }
+
+#[derive(Debug)]
+pub struct MissingUnsafe {
+    pub file: HirFileId,
+    pub expr: AstPtr<ast::Expr>,
+}
+
+impl Diagnostic for MissingUnsafe {
+    fn message(&self) -> String {
+        format!("This operation is unsafe and requires an unsafe function or block")
+    }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.expr.clone().into() }
+    }
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+impl AstDiagnostic for MissingUnsafe {
+    type AST = ast::Expr;
+
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.source().file_id).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::Expr::cast(node).unwrap()
+    }
+}
+
+#[derive(Debug)]
+pub struct MismatchedArgCount {
+    pub file: HirFileId,
+    pub call_expr: AstPtr<ast::Expr>,
+    pub expected: usize,
+    pub found: usize,
+}
+
+impl Diagnostic for MismatchedArgCount {
+    fn message(&self) -> String {
+        let s = if self.expected == 1 { "" } else { "s" };
+        format!("Expected {} argument{}, found {}", self.expected, s, self.found)
+    }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.call_expr.clone().into() }
+    }
+    fn as_any(&self) -> &(dyn Any + Send + 'static) {
+        self
+    }
+}
+
+impl AstDiagnostic for MismatchedArgCount {
+    type AST = ast::CallExpr;
+    fn ast(&self, db: &dyn AstDatabase) -> Self::AST {
+        let root = db.parse_or_expand(self.source().file_id).unwrap();
+        let node = self.source().value.to_node(&root);
+        ast::CallExpr::cast(node).unwrap()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId};
+    use hir_expand::diagnostics::{Diagnostic, DiagnosticSink};
+    use ra_db::{fixture::WithFixture, FileId, SourceDatabase, SourceDatabaseExt};
+    use ra_syntax::{TextRange, TextSize};
+    use rustc_hash::FxHashMap;
+
+    use crate::{diagnostics::validate_body, test_db::TestDB};
+
+    impl TestDB {
+        fn diagnostics<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
+            let crate_graph = self.crate_graph();
+            for krate in crate_graph.iter() {
+                let crate_def_map = self.crate_def_map(krate);
+
+                let mut fns = Vec::new();
+                for (module_id, _) in crate_def_map.modules.iter() {
+                    for decl in crate_def_map[module_id].scope.declarations() {
+                        if let ModuleDefId::FunctionId(f) = decl {
+                            fns.push(f)
+                        }
+                    }
+
+                    for impl_id in crate_def_map[module_id].scope.impls() {
+                        let impl_data = self.impl_data(impl_id);
+                        for item in impl_data.items.iter() {
+                            if let AssocItemId::FunctionId(f) = item {
+                                fns.push(*f)
+                            }
+                        }
+                    }
+                }
+
+                for f in fns {
+                    let mut sink = DiagnosticSink::new(&mut cb);
+                    validate_body(self, f.into(), &mut sink);
+                }
+            }
+        }
+    }
+
+    pub(crate) fn check_diagnostics(ra_fixture: &str) {
+        let db = TestDB::with_files(ra_fixture);
+        let annotations = db.extract_annotations();
+
+        let mut actual: FxHashMap<FileId, Vec<(TextRange, String)>> = FxHashMap::default();
+        db.diagnostics(|d| {
+            // FXIME: macros...
+            let file_id = d.source().file_id.original_file(&db);
+            let range = d.syntax_node(&db).text_range();
+            let message = d.message().to_owned();
+            actual.entry(file_id).or_default().push((range, message));
+        });
+
+        for (file_id, diags) in actual.iter_mut() {
+            diags.sort_by_key(|it| it.0.start());
+            let text = db.file_text(*file_id);
+            // For multiline spans, place them on line start
+            for (range, content) in diags {
+                if text[*range].contains('\n') {
+                    *range = TextRange::new(range.start(), range.start() + TextSize::from(1));
+                    *content = format!("... {}", content);
+                }
+            }
+        }
+
+        assert_eq!(annotations, actual);
+    }
+
+    #[test]
+    fn no_such_field_diagnostics() {
+        check_diagnostics(
+            r#"
+struct S { foo: i32, bar: () }
+impl S {
+    fn new() -> S {
+        S {
+        //^... Missing structure fields:
+        //|    - bar
+            foo: 92,
+            baz: 62,
+          //^^^^^^^ no such field
+        }
+    }
+}
+"#,
+        );
+    }
+    #[test]
+    fn no_such_field_with_feature_flag_diagnostics() {
+        check_diagnostics(
+            r#"
+//- /lib.rs crate:foo cfg:feature=foo
+struct MyStruct {
+    my_val: usize,
+    #[cfg(feature = "foo")]
+    bar: bool,
+}
+
+impl MyStruct {
+    #[cfg(feature = "foo")]
+    pub(crate) fn new(my_val: usize, bar: bool) -> Self {
+        Self { my_val, bar }
+    }
+    #[cfg(not(feature = "foo"))]
+    pub(crate) fn new(my_val: usize, _bar: bool) -> Self {
+        Self { my_val }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_such_field_enum_with_feature_flag_diagnostics() {
+        check_diagnostics(
+            r#"
+//- /lib.rs crate:foo cfg:feature=foo
+enum Foo {
+    #[cfg(not(feature = "foo"))]
+    Buz,
+    #[cfg(feature = "foo")]
+    Bar,
+    Baz
+}
+
+fn test_fn(f: Foo) {
+    match f {
+        Foo::Bar => {},
+        Foo::Baz => {},
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_such_field_with_feature_flag_diagnostics_on_struct_lit() {
+        check_diagnostics(
+            r#"
+//- /lib.rs crate:foo cfg:feature=foo
+struct S {
+    #[cfg(feature = "foo")]
+    foo: u32,
+    #[cfg(not(feature = "foo"))]
+    bar: u32,
+}
+
+impl S {
+    #[cfg(feature = "foo")]
+    fn new(foo: u32) -> Self {
+        Self { foo }
+    }
+    #[cfg(not(feature = "foo"))]
+    fn new(bar: u32) -> Self {
+        Self { bar }
+    }
+    fn new2(bar: u32) -> Self {
+        #[cfg(feature = "foo")]
+        { Self { foo: bar } }
+        #[cfg(not(feature = "foo"))]
+        { Self { bar } }
+    }
+    fn new2(val: u32) -> Self {
+        Self {
+            #[cfg(feature = "foo")]
+            foo: val,
+            #[cfg(not(feature = "foo"))]
+            bar: val,
+        }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn no_such_field_with_type_macro() {
+        check_diagnostics(
+            r#"
+macro_rules! Type { () => { u32 }; }
+struct Foo { bar: Type![] }
+
+impl Foo {
+    fn new() -> Self {
+        Foo { bar: 0 }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn missing_record_pat_field_diagnostic() {
+        check_diagnostics(
+            r#"
+struct S { foo: i32, bar: () }
+fn baz(s: S) {
+    let S { foo: _ } = s;
+        //^^^^^^^^^^ Missing structure fields:
+        //         | - bar
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn missing_record_pat_field_no_diagnostic_if_not_exhaustive() {
+        check_diagnostics(
+            r"
+struct S { foo: i32, bar: () }
+fn baz(s: S) -> i32 {
+    match s {
+        S { foo, .. } => foo,
+    }
+}
+",
+        )
+    }
+
+    #[test]
+    fn break_outside_of_loop() {
+        check_diagnostics(
+            r#"
+fn foo() { break; }
+         //^^^^^ break outside of loop
+"#,
+        );
+    }
+}
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/diagnostics/expr.rs
index f04968e14..557d01cdc 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/diagnostics/expr.rs
@@ -2,17 +2,19 @@
 
 use std::sync::Arc;
 
-use hir_def::{path::path, resolver::HasResolver, AdtId, FunctionId};
+use hir_def::{path::path, resolver::HasResolver, AdtId, DefWithBodyId};
 use hir_expand::diagnostics::DiagnosticSink;
 use ra_syntax::{ast, AstPtr};
 use rustc_hash::FxHashSet;
 
 use crate::{
     db::HirDatabase,
-    diagnostics::{MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields},
+    diagnostics::{
+        match_check::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
+        MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields,
+    },
     utils::variant_data,
     ApplicationTy, InferenceResult, Ty, TypeCtor,
-    _match::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
 };
 
 pub use hir_def::{
@@ -24,26 +26,27 @@ pub use hir_def::{
         ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal, LogicOp,
         MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement, UnaryOp,
     },
-    LocalFieldId, VariantId,
+    src::HasSource,
+    LocalFieldId, Lookup, VariantId,
 };
 
-pub struct ExprValidator<'a, 'b: 'a> {
-    func: FunctionId,
+pub(super) struct ExprValidator<'a, 'b: 'a> {
+    owner: DefWithBodyId,
     infer: Arc<InferenceResult>,
     sink: &'a mut DiagnosticSink<'b>,
 }
 
 impl<'a, 'b> ExprValidator<'a, 'b> {
-    pub fn new(
-        func: FunctionId,
+    pub(super) fn new(
+        owner: DefWithBodyId,
         infer: Arc<InferenceResult>,
         sink: &'a mut DiagnosticSink<'b>,
     ) -> ExprValidator<'a, 'b> {
-        ExprValidator { func, infer, sink }
+        ExprValidator { owner, infer, sink }
     }
 
-    pub fn validate_body(&mut self, db: &dyn HirDatabase) {
-        let body = db.body(self.func.into());
+    pub(super) fn validate_body(&mut self, db: &dyn HirDatabase) {
+        let body = db.body(self.owner.into());
 
         for (id, expr) in body.exprs.iter() {
             if let Some((variant_def, missed_fields, true)) =
@@ -56,8 +59,15 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                     missed_fields,
                 );
             }
-            if let Expr::Match { expr, arms } = expr {
-                self.validate_match(id, *expr, arms, db, self.infer.clone());
+
+            match expr {
+                Expr::Match { expr, arms } => {
+                    self.validate_match(id, *expr, arms, db, self.infer.clone());
+                }
+                Expr::Call { .. } | Expr::MethodCall { .. } => {
+                    self.validate_call(db, id, expr);
+                }
+                _ => {}
             }
         }
         for (id, pat) in body.pats.iter() {
@@ -86,7 +96,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         missed_fields: Vec<LocalFieldId>,
     ) {
         // XXX: only look at source_map if we do have missing fields
-        let (_, source_map) = db.body_with_source_map(self.func.into());
+        let (_, source_map) = db.body_with_source_map(self.owner.into());
 
         if let Ok(source_ptr) = source_map.expr_syntax(id) {
             let root = source_ptr.file_syntax(db.upcast());
@@ -115,7 +125,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         missed_fields: Vec<LocalFieldId>,
     ) {
         // XXX: only look at source_map if we do have missing fields
-        let (_, source_map) = db.body_with_source_map(self.func.into());
+        let (_, source_map) = db.body_with_source_map(self.owner.into());
 
         if let Ok(source_ptr) = source_map.pat_syntax(id) {
             if let Some(expr) = source_ptr.value.as_ref().left() {
@@ -138,6 +148,61 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         }
     }
 
+    fn validate_call(&mut self, db: &dyn HirDatabase, call_id: ExprId, expr: &Expr) -> Option<()> {
+        // Check that the number of arguments matches the number of parameters.
+
+        // FIXME: Due to shortcomings in the current type system implementation, only emit this
+        // diagnostic if there are no type mismatches in the containing function.
+        if self.infer.type_mismatches.iter().next().is_some() {
+            return Some(());
+        }
+
+        let is_method_call = matches!(expr, Expr::MethodCall { .. });
+        let (callee, args) = match expr {
+            Expr::Call { callee, args } => {
+                let callee = &self.infer.type_of_expr[*callee];
+                let (callable, _) = callee.as_callable()?;
+
+                (callable, args.clone())
+            }
+            Expr::MethodCall { receiver, args, .. } => {
+                let callee = self.infer.method_resolution(call_id)?;
+                let mut args = args.clone();
+                args.insert(0, *receiver);
+                (callee.into(), args)
+            }
+            _ => return None,
+        };
+
+        let sig = db.callable_item_signature(callee);
+        if sig.value.is_varargs {
+            return None;
+        }
+
+        let params = sig.value.params();
+
+        let mut param_count = params.len();
+        let mut arg_count = args.len();
+
+        if arg_count != param_count {
+            let (_, source_map) = db.body_with_source_map(self.owner.into());
+            if let Ok(source_ptr) = source_map.expr_syntax(call_id) {
+                if is_method_call {
+                    param_count -= 1;
+                    arg_count -= 1;
+                }
+                self.sink.push(MismatchedArgCount {
+                    file: source_ptr.file_id,
+                    call_expr: source_ptr.value,
+                    expected: param_count,
+                    found: arg_count,
+                });
+            }
+        }
+
+        None
+    }
+
     fn validate_match(
         &mut self,
         id: ExprId,
@@ -147,7 +212,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         infer: Arc<InferenceResult>,
     ) {
         let (body, source_map): (Arc<Body>, Arc<BodySourceMap>) =
-            db.body_with_source_map(self.func.into());
+            db.body_with_source_map(self.owner.into());
 
         let match_expr_ty = match infer.type_of_expr.get(match_expr) {
             Some(ty) => ty,
@@ -226,22 +291,24 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             None => return,
         };
 
-        let std_result_path = path![std::result::Result];
+        let core_result_path = path![core::result::Result];
 
-        let resolver = self.func.resolver(db.upcast());
-        let std_result_enum = match resolver.resolve_known_enum(db.upcast(), &std_result_path) {
+        let resolver = self.owner.resolver(db.upcast());
+        let core_result_enum = match resolver.resolve_known_enum(db.upcast(), &core_result_path) {
             Some(it) => it,
             _ => return,
         };
 
-        let std_result_ctor = TypeCtor::Adt(AdtId::EnumId(std_result_enum));
+        let core_result_ctor = TypeCtor::Adt(AdtId::EnumId(core_result_enum));
         let params = match &mismatch.expected {
-            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &std_result_ctor => parameters,
+            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_result_ctor => {
+                parameters
+            }
             _ => return,
         };
 
         if params.len() == 2 && params[0] == mismatch.actual {
-            let (_, source_map) = db.body_with_source_map(self.func.into());
+            let (_, source_map) = db.body_with_source_map(self.owner.into());
 
             if let Ok(source_ptr) = source_map.expr_syntax(id) {
                 self.sink
@@ -310,3 +377,169 @@ pub fn record_pattern_missing_fields(
     }
     Some((variant_def, missed_fields, exhaustive))
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostics::tests::check_diagnostics;
+
+    #[test]
+    fn simple_free_fn_zero() {
+        check_diagnostics(
+            r#"
+fn zero() {}
+fn f() { zero(1); }
+       //^^^^^^^ Expected 0 arguments, found 1
+"#,
+        );
+
+        check_diagnostics(
+            r#"
+fn zero() {}
+fn f() { zero(); }
+"#,
+        );
+    }
+
+    #[test]
+    fn simple_free_fn_one() {
+        check_diagnostics(
+            r#"
+fn one(arg: u8) {}
+fn f() { one(); }
+       //^^^^^ Expected 1 argument, found 0
+"#,
+        );
+
+        check_diagnostics(
+            r#"
+fn one(arg: u8) {}
+fn f() { one(1); }
+"#,
+        );
+    }
+
+    #[test]
+    fn method_as_fn() {
+        check_diagnostics(
+            r#"
+struct S;
+impl S { fn method(&self) {} }
+
+fn f() {
+    S::method();
+} //^^^^^^^^^^^ Expected 1 argument, found 0
+"#,
+        );
+
+        check_diagnostics(
+            r#"
+struct S;
+impl S { fn method(&self) {} }
+
+fn f() {
+    S::method(&S);
+    S.method();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn method_with_arg() {
+        check_diagnostics(
+            r#"
+struct S;
+impl S { fn method(&self, arg: u8) {} }
+
+            fn f() {
+                S.method();
+            } //^^^^^^^^^^ Expected 1 argument, found 0
+            "#,
+        );
+
+        check_diagnostics(
+            r#"
+struct S;
+impl S { fn method(&self, arg: u8) {} }
+
+fn f() {
+    S::method(&S, 0);
+    S.method(1);
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn tuple_struct() {
+        check_diagnostics(
+            r#"
+struct Tup(u8, u16);
+fn f() {
+    Tup(0);
+} //^^^^^^ Expected 2 arguments, found 1
+"#,
+        )
+    }
+
+    #[test]
+    fn enum_variant() {
+        check_diagnostics(
+            r#"
+enum En { Variant(u8, u16), }
+fn f() {
+    En::Variant(0);
+} //^^^^^^^^^^^^^^ Expected 2 arguments, found 1
+"#,
+        )
+    }
+
+    #[test]
+    fn enum_variant_type_macro() {
+        check_diagnostics(
+            r#"
+macro_rules! Type {
+    () => { u32 };
+}
+enum Foo {
+    Bar(Type![])
+}
+impl Foo {
+    fn new() {
+        Foo::Bar(0);
+        Foo::Bar(0, 1);
+      //^^^^^^^^^^^^^^ Expected 1 argument, found 2
+        Foo::Bar();
+      //^^^^^^^^^^ Expected 1 argument, found 0
+    }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn varargs() {
+        check_diagnostics(
+            r#"
+extern "C" {
+    fn fixed(fixed: u8);
+    fn varargs(fixed: u8, ...);
+    fn varargs2(...);
+}
+
+fn f() {
+    unsafe {
+        fixed(0);
+        fixed(0, 1);
+      //^^^^^^^^^^^ Expected 1 argument, found 2
+        varargs(0);
+        varargs(0, 1);
+        varargs2();
+        varargs2(0);
+        varargs2(0, 1);
+    }
+}
+        "#,
+        )
+    }
+}
diff --git a/crates/ra_hir_ty/src/diagnostics/match_check.rs b/crates/ra_hir_ty/src/diagnostics/match_check.rs
new file mode 100644
index 000000000..507edcb7d
--- /dev/null
+++ b/crates/ra_hir_ty/src/diagnostics/match_check.rs
@@ -0,0 +1,1421 @@
+//! This module implements match statement exhaustiveness checking and usefulness checking
+//! for match arms.
+//!
+//! It is modeled on the rustc module `librustc_mir_build::hair::pattern::_match`, which
+//! contains very detailed documentation about the algorithms used here. I've duplicated
+//! most of that documentation below.
+//!
+//! This file includes the logic for exhaustiveness and usefulness checking for
+//! pattern-matching. Specifically, given a list of patterns for a type, we can
+//! tell whether:
+//! - (a) the patterns cover every possible constructor for the type (exhaustiveness).
+//! - (b) each pattern is necessary (usefulness).
+//!
+//! The algorithm implemented here is a modified version of the one described in
+//! <http://moscova.inria.fr/~maranget/papers/warn/index.html>.
+//! However, to save future implementors from reading the original paper, we
+//! summarise the algorithm here to hopefully save time and be a little clearer
+//! (without being so rigorous).
+//!
+//! The core of the algorithm revolves about a "usefulness" check. In particular, we
+//! are trying to compute a predicate `U(P, p)` where `P` is a list of patterns (we refer to this as
+//! a matrix). `U(P, p)` represents whether, given an existing list of patterns
+//! `P_1 ..= P_m`, adding a new pattern `p` will be "useful" (that is, cover previously-
+//! uncovered values of the type).
+//!
+//! If we have this predicate, then we can easily compute both exhaustiveness of an
+//! entire set of patterns and the individual usefulness of each one.
+//! (a) the set of patterns is exhaustive iff `U(P, _)` is false (i.e., adding a wildcard
+//! match doesn't increase the number of values we're matching)
+//! (b) a pattern `P_i` is not useful if `U(P[0..=(i-1), P_i)` is false (i.e., adding a
+//! pattern to those that have come before it doesn't increase the number of values
+//! we're matching).
+//!
+//! During the course of the algorithm, the rows of the matrix won't just be individual patterns,
+//! but rather partially-deconstructed patterns in the form of a list of patterns. The paper
+//! calls those pattern-vectors, and we will call them pattern-stacks. The same holds for the
+//! new pattern `p`.
+//!
+//! For example, say we have the following:
+//!
+//! ```ignore
+//! // x: (Option<bool>, Result<()>)
+//! match x {
+//!     (Some(true), _) => (),
+//!     (None, Err(())) => (),
+//!     (None, Err(_)) => (),
+//! }
+//! ```
+//!
+//! Here, the matrix `P` starts as:
+//!
+//! ```text
+//! [
+//!     [(Some(true), _)],
+//!     [(None, Err(()))],
+//!     [(None, Err(_))],
+//! ]
+//! ```
+//!
+//! We can tell it's not exhaustive, because `U(P, _)` is true (we're not covering
+//! `[(Some(false), _)]`, for instance). In addition, row 3 is not useful, because
+//! all the values it covers are already covered by row 2.
+//!
+//! A list of patterns can be thought of as a stack, because we are mainly interested in the top of
+//! the stack at any given point, and we can pop or apply constructors to get new pattern-stacks.
+//! To match the paper, the top of the stack is at the beginning / on the left.
+//!
+//! There are two important operations on pattern-stacks necessary to understand the algorithm:
+//!
+//! 1. We can pop a given constructor off the top of a stack. This operation is called
+//!    `specialize`, and is denoted `S(c, p)` where `c` is a constructor (like `Some` or
+//!    `None`) and `p` a pattern-stack.
+//!    If the pattern on top of the stack can cover `c`, this removes the constructor and
+//!    pushes its arguments onto the stack. It also expands OR-patterns into distinct patterns.
+//!    Otherwise the pattern-stack is discarded.
+//!    This essentially filters those pattern-stacks whose top covers the constructor `c` and
+//!    discards the others.
+//!
+//!    For example, the first pattern above initially gives a stack `[(Some(true), _)]`. If we
+//!    pop the tuple constructor, we are left with `[Some(true), _]`, and if we then pop the
+//!    `Some` constructor we get `[true, _]`. If we had popped `None` instead, we would get
+//!    nothing back.
+//!
+//!    This returns zero or more new pattern-stacks, as follows. We look at the pattern `p_1`
+//!    on top of the stack, and we have four cases:
+//!
+//!    * 1.1. `p_1 = c(r_1, .., r_a)`, i.e. the top of the stack has constructor `c`. We push onto
+//!           the stack the arguments of this constructor, and return the result:
+//!
+//!          r_1, .., r_a, p_2, .., p_n
+//!
+//!    * 1.2. `p_1 = c'(r_1, .., r_a')` where `c ≠ c'`. We discard the current stack and return
+//!           nothing.
+//!    * 1.3. `p_1 = _`. We push onto the stack as many wildcards as the constructor `c` has
+//!           arguments (its arity), and return the resulting stack:
+//!
+//!          _, .., _, p_2, .., p_n
+//!
+//!    * 1.4. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting stack:
+//!
+//!          S(c, (r_1, p_2, .., p_n))
+//!          S(c, (r_2, p_2, .., p_n))
+//!
+//! 2. We can pop a wildcard off the top of the stack. This is called `D(p)`, where `p` is
+//!    a pattern-stack.
+//!    This is used when we know there are missing constructor cases, but there might be
+//!    existing wildcard patterns, so to check the usefulness of the matrix, we have to check
+//!    all its *other* components.
+//!
+//!    It is computed as follows. We look at the pattern `p_1` on top of the stack,
+//!    and we have three cases:
+//!    * 1.1. `p_1 = c(r_1, .., r_a)`. We discard the current stack and return nothing.
+//!    * 1.2. `p_1 = _`. We return the rest of the stack:
+//!
+//!          p_2, .., p_n
+//!
+//!    * 1.3. `p_1 = r_1 | r_2`. We expand the OR-pattern and then recurse on each resulting stack:
+//!
+//!          D((r_1, p_2, .., p_n))
+//!          D((r_2, p_2, .., p_n))
+//!
+//!    Note that the OR-patterns are not always used directly in Rust, but are used to derive the
+//!    exhaustive integer matching rules, so they're written here for posterity.
+//!
+//! Both those operations extend straightforwardly to a list or pattern-stacks, i.e. a matrix, by
+//! working row-by-row. Popping a constructor ends up keeping only the matrix rows that start with
+//! the given constructor, and popping a wildcard keeps those rows that start with a wildcard.
+//!
+//!
+//! The algorithm for computing `U`
+//! -------------------------------
+//! The algorithm is inductive (on the number of columns: i.e., components of tuple patterns).
+//! That means we're going to check the components from left-to-right, so the algorithm
+//! operates principally on the first component of the matrix and new pattern-stack `p`.
+//! This algorithm is realised in the `is_useful` function.
+//!
+//! Base case (`n = 0`, i.e., an empty tuple pattern):
+//! - If `P` already contains an empty pattern (i.e., if the number of patterns `m > 0`), then
+//!   `U(P, p)` is false.
+//! - Otherwise, `P` must be empty, so `U(P, p)` is true.
+//!
+//! Inductive step (`n > 0`, i.e., whether there's at least one column [which may then be expanded
+//! into further columns later]). We're going to match on the top of the new pattern-stack, `p_1`:
+//!
+//! - If `p_1 == c(r_1, .., r_a)`, i.e. we have a constructor pattern.
+//!   Then, the usefulness of `p_1` can be reduced to whether it is useful when
+//!   we ignore all the patterns in the first column of `P` that involve other constructors.
+//!   This is where `S(c, P)` comes in:
+//!
+//!   ```text
+//!   U(P, p) := U(S(c, P), S(c, p))
+//!   ```
+//!
+//!   This special case is handled in `is_useful_specialized`.
+//!
+//!   For example, if `P` is:
+//!
+//!   ```text
+//!   [
+//!       [Some(true), _],
+//!       [None, 0],
+//!   ]
+//!   ```
+//!
+//!   and `p` is `[Some(false), 0]`, then we don't care about row 2 since we know `p` only
+//!   matches values that row 2 doesn't. For row 1 however, we need to dig into the
+//!   arguments of `Some` to know whether some new value is covered. So we compute
+//!   `U([[true, _]], [false, 0])`.
+//!
+//! - If `p_1 == _`, then we look at the list of constructors that appear in the first component of
+//!   the rows of `P`:
+//!     - If there are some constructors that aren't present, then we might think that the
+//!       wildcard `_` is useful, since it covers those constructors that weren't covered
+//!       before.
+//!       That's almost correct, but only works if there were no wildcards in those first
+//!       components. So we need to check that `p` is useful with respect to the rows that
+//!       start with a wildcard, if there are any. This is where `D` comes in:
+//!       `U(P, p) := U(D(P), D(p))`
+//!
+//!       For example, if `P` is:
+//!       ```text
+//!       [
+//!           [_, true, _],
+//!           [None, false, 1],
+//!       ]
+//!       ```
+//!       and `p` is `[_, false, _]`, the `Some` constructor doesn't appear in `P`. So if we
+//!       only had row 2, we'd know that `p` is useful. However row 1 starts with a
+//!       wildcard, so we need to check whether `U([[true, _]], [false, 1])`.
+//!
+//!     - Otherwise, all possible constructors (for the relevant type) are present. In this
+//!       case we must check whether the wildcard pattern covers any unmatched value. For
+//!       that, we can think of the `_` pattern as a big OR-pattern that covers all
+//!       possible constructors. For `Option`, that would mean `_ = None | Some(_)` for
+//!       example. The wildcard pattern is useful in this case if it is useful when
+//!       specialized to one of the possible constructors. So we compute:
+//!       `U(P, p) := ∃(k ϵ constructors) U(S(k, P), S(k, p))`
+//!
+//!       For example, if `P` is:
+//!       ```text
+//!       [
+//!           [Some(true), _],
+//!           [None, false],
+//!       ]
+//!       ```
+//!       and `p` is `[_, false]`, both `None` and `Some` constructors appear in the first
+//!       components of `P`. We will therefore try popping both constructors in turn: we
+//!       compute `U([[true, _]], [_, false])` for the `Some` constructor, and `U([[false]],
+//!       [false])` for the `None` constructor. The first case returns true, so we know that
+//!       `p` is useful for `P`. Indeed, it matches `[Some(false), _]` that wasn't matched
+//!       before.
+//!
+//! - If `p_1 == r_1 | r_2`, then the usefulness depends on each `r_i` separately:
+//!
+//!   ```text
+//!   U(P, p) := U(P, (r_1, p_2, .., p_n))
+//!            || U(P, (r_2, p_2, .., p_n))
+//!   ```
+use std::sync::Arc;
+
+use hir_def::{
+    adt::VariantData,
+    body::Body,
+    expr::{Expr, Literal, Pat, PatId},
+    AdtId, EnumVariantId, VariantId,
+};
+use ra_arena::Idx;
+use smallvec::{smallvec, SmallVec};
+
+use crate::{db::HirDatabase, ApplicationTy, InferenceResult, Ty, TypeCtor};
+
+#[derive(Debug, Clone, Copy)]
+/// Either a pattern from the source code being analyzed, represented as
+/// as `PatId`, or a `Wild` pattern which is created as an intermediate
+/// step in the match checking algorithm and thus is not backed by a
+/// real `PatId`.
+///
+/// Note that it is totally valid for the `PatId` variant to contain
+/// a `PatId` which resolves to a `Wild` pattern, if that wild pattern
+/// exists in the source code being analyzed.
+enum PatIdOrWild {
+    PatId(PatId),
+    Wild,
+}
+
+impl PatIdOrWild {
+    fn as_pat(self, cx: &MatchCheckCtx) -> Pat {
+        match self {
+            PatIdOrWild::PatId(id) => cx.body.pats[id].clone(),
+            PatIdOrWild::Wild => Pat::Wild,
+        }
+    }
+
+    fn as_id(self) -> Option<PatId> {
+        match self {
+            PatIdOrWild::PatId(id) => Some(id),
+            PatIdOrWild::Wild => None,
+        }
+    }
+}
+
+impl From<PatId> for PatIdOrWild {
+    fn from(pat_id: PatId) -> Self {
+        Self::PatId(pat_id)
+    }
+}
+
+impl From<&PatId> for PatIdOrWild {
+    fn from(pat_id: &PatId) -> Self {
+        Self::PatId(*pat_id)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub(super) enum MatchCheckErr {
+    NotImplemented,
+    MalformedMatchArm,
+    /// Used when type inference cannot resolve the type of
+    /// a pattern or expression.
+    Unknown,
+}
+
+/// The return type of `is_useful` is either an indication of usefulness
+/// of the match arm, or an error in the case the match statement
+/// is made up of types for which exhaustiveness checking is currently
+/// not completely implemented.
+///
+/// The `std::result::Result` type is used here rather than a custom enum
+/// to allow the use of `?`.
+pub(super) type MatchCheckResult<T> = Result<T, MatchCheckErr>;
+
+#[derive(Debug)]
+/// A row in a Matrix.
+///
+/// This type is modeled from the struct of the same name in `rustc`.
+pub(super) struct PatStack(PatStackInner);
+type PatStackInner = SmallVec<[PatIdOrWild; 2]>;
+
+impl PatStack {
+    pub(super) fn from_pattern(pat_id: PatId) -> PatStack {
+        Self(smallvec!(pat_id.into()))
+    }
+
+    pub(super) fn from_wild() -> PatStack {
+        Self(smallvec!(PatIdOrWild::Wild))
+    }
+
+    fn from_slice(slice: &[PatIdOrWild]) -> PatStack {
+        Self(SmallVec::from_slice(slice))
+    }
+
+    fn from_vec(v: PatStackInner) -> PatStack {
+        Self(v)
+    }
+
+    fn get_head(&self) -> Option<PatIdOrWild> {
+        self.0.first().copied()
+    }
+
+    fn tail(&self) -> &[PatIdOrWild] {
+        self.0.get(1..).unwrap_or(&[])
+    }
+
+    fn to_tail(&self) -> PatStack {
+        Self::from_slice(self.tail())
+    }
+
+    fn replace_head_with<I, T>(&self, pats: I) -> PatStack
+    where
+        I: Iterator<Item = T>,
+        T: Into<PatIdOrWild>,
+    {
+        let mut patterns: PatStackInner = smallvec![];
+        for pat in pats {
+            patterns.push(pat.into());
+        }
+        for pat in &self.0[1..] {
+            patterns.push(*pat);
+        }
+        PatStack::from_vec(patterns)
+    }
+
+    /// Computes `D(self)`.
+    ///
+    /// See the module docs and the associated documentation in rustc for details.
+    fn specialize_wildcard(&self, cx: &MatchCheckCtx) -> Option<PatStack> {
+        if matches!(self.get_head()?.as_pat(cx), Pat::Wild) {
+            Some(self.to_tail())
+        } else {
+            None
+        }
+    }
+
+    /// Computes `S(constructor, self)`.
+    ///
+    /// See the module docs and the associated documentation in rustc for details.
+    fn specialize_constructor(
+        &self,
+        cx: &MatchCheckCtx,
+        constructor: &Constructor,
+    ) -> MatchCheckResult<Option<PatStack>> {
+        let head = match self.get_head() {
+            Some(head) => head,
+            None => return Ok(None),
+        };
+
+        let head_pat = head.as_pat(cx);
+        let result = match (head_pat, constructor) {
+            (Pat::Tuple { args: ref pat_ids, ellipsis }, Constructor::Tuple { arity: _ }) => {
+                if ellipsis.is_some() {
+                    // If there are ellipsis here, we should add the correct number of
+                    // Pat::Wild patterns to `pat_ids`. We should be able to use the
+                    // constructors arity for this, but at the time of writing we aren't
+                    // correctly calculating this arity when ellipsis are present.
+                    return Err(MatchCheckErr::NotImplemented);
+                }
+
+                Some(self.replace_head_with(pat_ids.iter()))
+            }
+            (Pat::Lit(lit_expr), Constructor::Bool(constructor_val)) => {
+                match cx.body.exprs[lit_expr] {
+                    Expr::Literal(Literal::Bool(pat_val)) if *constructor_val == pat_val => {
+                        Some(self.to_tail())
+                    }
+                    // it was a bool but the value doesn't match
+                    Expr::Literal(Literal::Bool(_)) => None,
+                    // perhaps this is actually unreachable given we have
+                    // already checked that these match arms have the appropriate type?
+                    _ => return Err(MatchCheckErr::NotImplemented),
+                }
+            }
+            (Pat::Wild, constructor) => Some(self.expand_wildcard(cx, constructor)?),
+            (Pat::Path(_), Constructor::Enum(constructor)) => {
+                // unit enum variants become `Pat::Path`
+                let pat_id = head.as_id().expect("we know this isn't a wild");
+                if !enum_variant_matches(cx, pat_id, *constructor) {
+                    None
+                } else {
+                    Some(self.to_tail())
+                }
+            }
+            (
+                Pat::TupleStruct { args: ref pat_ids, ellipsis, .. },
+                Constructor::Enum(enum_constructor),
+            ) => {
+                let pat_id = head.as_id().expect("we know this isn't a wild");
+                if !enum_variant_matches(cx, pat_id, *enum_constructor) {
+                    None
+                } else {
+                    let constructor_arity = constructor.arity(cx)?;
+                    if let Some(ellipsis_position) = ellipsis {
+                        // If there are ellipsis in the pattern, the ellipsis must take the place
+                        // of at least one sub-pattern, so `pat_ids` should be smaller than the
+                        // constructor arity.
+                        if pat_ids.len() < constructor_arity {
+                            let mut new_patterns: Vec<PatIdOrWild> = vec![];
+
+                            for pat_id in &pat_ids[0..ellipsis_position] {
+                                new_patterns.push((*pat_id).into());
+                            }
+
+                            for _ in 0..(constructor_arity - pat_ids.len()) {
+                                new_patterns.push(PatIdOrWild::Wild);
+                            }
+
+                            for pat_id in &pat_ids[ellipsis_position..pat_ids.len()] {
+                                new_patterns.push((*pat_id).into());
+                            }
+
+                            Some(self.replace_head_with(new_patterns.into_iter()))
+                        } else {
+                            return Err(MatchCheckErr::MalformedMatchArm);
+                        }
+                    } else {
+                        // If there is no ellipsis in the tuple pattern, the number
+                        // of patterns must equal the constructor arity.
+                        if pat_ids.len() == constructor_arity {
+                            Some(self.replace_head_with(pat_ids.into_iter()))
+                        } else {
+                            return Err(MatchCheckErr::MalformedMatchArm);
+                        }
+                    }
+                }
+            }
+            (Pat::Record { args: ref arg_patterns, .. }, Constructor::Enum(e)) => {
+                let pat_id = head.as_id().expect("we know this isn't a wild");
+                if !enum_variant_matches(cx, pat_id, *e) {
+                    None
+                } else {
+                    match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
+                        VariantData::Record(struct_field_arena) => {
+                            // Here we treat any missing fields in the record as the wild pattern, as
+                            // if the record has ellipsis. We want to do this here even if the
+                            // record does not contain ellipsis, because it allows us to continue
+                            // enforcing exhaustiveness for the rest of the match statement.
+                            //
+                            // Creating the diagnostic for the missing field in the pattern
+                            // should be done in a different diagnostic.
+                            let patterns = struct_field_arena.iter().map(|(_, struct_field)| {
+                                arg_patterns
+                                    .iter()
+                                    .find(|pat| pat.name == struct_field.name)
+                                    .map(|pat| PatIdOrWild::from(pat.pat))
+                                    .unwrap_or(PatIdOrWild::Wild)
+                            });
+
+                            Some(self.replace_head_with(patterns))
+                        }
+                        _ => return Err(MatchCheckErr::Unknown),
+                    }
+                }
+            }
+            (Pat::Or(_), _) => return Err(MatchCheckErr::NotImplemented),
+            (_, _) => return Err(MatchCheckErr::NotImplemented),
+        };
+
+        Ok(result)
+    }
+
+    /// A special case of `specialize_constructor` where the head of the pattern stack
+    /// is a Wild pattern.
+    ///
+    /// Replaces the Wild pattern at the head of the pattern stack with N Wild patterns
+    /// (N >= 0), where N is the arity of the given constructor.
+    fn expand_wildcard(
+        &self,
+        cx: &MatchCheckCtx,
+        constructor: &Constructor,
+    ) -> MatchCheckResult<PatStack> {
+        assert_eq!(
+            Pat::Wild,
+            self.get_head().expect("expand_wildcard called on empty PatStack").as_pat(cx),
+            "expand_wildcard must only be called on PatStack with wild at head",
+        );
+
+        let mut patterns: PatStackInner = smallvec![];
+
+        for _ in 0..constructor.arity(cx)? {
+            patterns.push(PatIdOrWild::Wild);
+        }
+
+        for pat in &self.0[1..] {
+            patterns.push(*pat);
+        }
+
+        Ok(PatStack::from_vec(patterns))
+    }
+}
+
+/// A collection of PatStack.
+///
+/// This type is modeled from the struct of the same name in `rustc`.
+pub(super) struct Matrix(Vec<PatStack>);
+
+impl Matrix {
+    pub(super) fn empty() -> Self {
+        Self(vec![])
+    }
+
+    pub(super) fn push(&mut self, cx: &MatchCheckCtx, row: PatStack) {
+        if let Some(Pat::Or(pat_ids)) = row.get_head().map(|pat_id| pat_id.as_pat(cx)) {
+            // Or patterns are expanded here
+            for pat_id in pat_ids {
+                self.0.push(PatStack::from_pattern(pat_id));
+            }
+        } else {
+            self.0.push(row);
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    fn heads(&self) -> Vec<PatIdOrWild> {
+        self.0.iter().flat_map(|p| p.get_head()).collect()
+    }
+
+    /// Computes `D(self)` for each contained PatStack.
+    ///
+    /// See the module docs and the associated documentation in rustc for details.
+    fn specialize_wildcard(&self, cx: &MatchCheckCtx) -> Self {
+        Self::collect(cx, self.0.iter().filter_map(|r| r.specialize_wildcard(cx)))
+    }
+
+    /// Computes `S(constructor, self)` for each contained PatStack.
+    ///
+    /// See the module docs and the associated documentation in rustc for details.
+    fn specialize_constructor(
+        &self,
+        cx: &MatchCheckCtx,
+        constructor: &Constructor,
+    ) -> MatchCheckResult<Self> {
+        let mut new_matrix = Matrix::empty();
+        for pat in &self.0 {
+            if let Some(pat) = pat.specialize_constructor(cx, constructor)? {
+                new_matrix.push(cx, pat);
+            }
+        }
+
+        Ok(new_matrix)
+    }
+
+    fn collect<T: IntoIterator<Item = PatStack>>(cx: &MatchCheckCtx, iter: T) -> Self {
+        let mut matrix = Matrix::empty();
+
+        for pat in iter {
+            // using push ensures we expand or-patterns
+            matrix.push(cx, pat);
+        }
+
+        matrix
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+/// An indication of the usefulness of a given match arm, where
+/// usefulness is defined as matching some patterns which were
+/// not matched by an prior match arms.
+///
+/// We may eventually need an `Unknown` variant here.
+pub(super) enum Usefulness {
+    Useful,
+    NotUseful,
+}
+
+pub(super) struct MatchCheckCtx<'a> {
+    pub(super) match_expr: Idx<Expr>,
+    pub(super) body: Arc<Body>,
+    pub(super) infer: Arc<InferenceResult>,
+    pub(super) db: &'a dyn HirDatabase,
+}
+
+/// Given a set of patterns `matrix`, and pattern to consider `v`, determines
+/// whether `v` is useful. A pattern is useful if it covers cases which were
+/// not previously covered.
+///
+/// When calling this function externally (that is, not the recursive calls) it
+/// expected that you have already type checked the match arms. All patterns in
+/// matrix should be the same type as v, as well as they should all be the same
+/// type as the match expression.
+pub(super) fn is_useful(
+    cx: &MatchCheckCtx,
+    matrix: &Matrix,
+    v: &PatStack,
+) -> MatchCheckResult<Usefulness> {
+    // Handle two special cases:
+    // - enum with no variants
+    // - `!` type
+    // In those cases, no match arm is useful.
+    match cx.infer[cx.match_expr].strip_references() {
+        Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(AdtId::EnumId(enum_id)), .. }) => {
+            if cx.db.enum_data(*enum_id).variants.is_empty() {
+                return Ok(Usefulness::NotUseful);
+            }
+        }
+        Ty::Apply(ApplicationTy { ctor: TypeCtor::Never, .. }) => {
+            return Ok(Usefulness::NotUseful);
+        }
+        _ => (),
+    }
+
+    let head = match v.get_head() {
+        Some(head) => head,
+        None => {
+            let result = if matrix.is_empty() { Usefulness::Useful } else { Usefulness::NotUseful };
+
+            return Ok(result);
+        }
+    };
+
+    if let Pat::Or(pat_ids) = head.as_pat(cx) {
+        let mut found_unimplemented = false;
+        let any_useful = pat_ids.iter().any(|&pat_id| {
+            let v = PatStack::from_pattern(pat_id);
+
+            match is_useful(cx, matrix, &v) {
+                Ok(Usefulness::Useful) => true,
+                Ok(Usefulness::NotUseful) => false,
+                _ => {
+                    found_unimplemented = true;
+                    false
+                }
+            }
+        });
+
+        return if any_useful {
+            Ok(Usefulness::Useful)
+        } else if found_unimplemented {
+            Err(MatchCheckErr::NotImplemented)
+        } else {
+            Ok(Usefulness::NotUseful)
+        };
+    }
+
+    if let Some(constructor) = pat_constructor(cx, head)? {
+        let matrix = matrix.specialize_constructor(&cx, &constructor)?;
+        let v = v
+            .specialize_constructor(&cx, &constructor)?
+            .expect("we know this can't fail because we get the constructor from `v.head()` above");
+
+        is_useful(&cx, &matrix, &v)
+    } else {
+        // expanding wildcard
+        let mut used_constructors: Vec<Constructor> = vec![];
+        for pat in matrix.heads() {
+            if let Some(constructor) = pat_constructor(cx, pat)? {
+                used_constructors.push(constructor);
+            }
+        }
+
+        // We assume here that the first constructor is the "correct" type. Since we
+        // only care about the "type" of the constructor (i.e. if it is a bool we
+        // don't care about the value), this assumption should be valid as long as
+        // the match statement is well formed. We currently uphold this invariant by
+        // filtering match arms before calling `is_useful`, only passing in match arms
+        // whose type matches the type of the match expression.
+        match &used_constructors.first() {
+            Some(constructor) if all_constructors_covered(&cx, constructor, &used_constructors) => {
+                // If all constructors are covered, then we need to consider whether
+                // any values are covered by this wildcard.
+                //
+                // For example, with matrix '[[Some(true)], [None]]', all
+                // constructors are covered (`Some`/`None`), so we need
+                // to perform specialization to see that our wildcard will cover
+                // the `Some(false)` case.
+                //
+                // Here we create a constructor for each variant and then check
+                // usefulness after specializing for that constructor.
+                let mut found_unimplemented = false;
+                for constructor in constructor.all_constructors(cx) {
+                    let matrix = matrix.specialize_constructor(&cx, &constructor)?;
+                    let v = v.expand_wildcard(&cx, &constructor)?;
+
+                    match is_useful(&cx, &matrix, &v) {
+                        Ok(Usefulness::Useful) => return Ok(Usefulness::Useful),
+                        Ok(Usefulness::NotUseful) => continue,
+                        _ => found_unimplemented = true,
+                    };
+                }
+
+                if found_unimplemented {
+                    Err(MatchCheckErr::NotImplemented)
+                } else {
+                    Ok(Usefulness::NotUseful)
+                }
+            }
+            _ => {
+                // Either not all constructors are covered, or the only other arms
+                // are wildcards. Either way, this pattern is useful if it is useful
+                // when compared to those arms with wildcards.
+                let matrix = matrix.specialize_wildcard(&cx);
+                let v = v.to_tail();
+
+                is_useful(&cx, &matrix, &v)
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+/// Similar to TypeCtor, but includes additional information about the specific
+/// value being instantiated. For example, TypeCtor::Bool doesn't contain the
+/// boolean value.
+enum Constructor {
+    Bool(bool),
+    Tuple { arity: usize },
+    Enum(EnumVariantId),
+}
+
+impl Constructor {
+    fn arity(&self, cx: &MatchCheckCtx) -> MatchCheckResult<usize> {
+        let arity = match self {
+            Constructor::Bool(_) => 0,
+            Constructor::Tuple { arity } => *arity,
+            Constructor::Enum(e) => {
+                match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
+                    VariantData::Tuple(struct_field_data) => struct_field_data.len(),
+                    VariantData::Record(struct_field_data) => struct_field_data.len(),
+                    VariantData::Unit => 0,
+                }
+            }
+        };
+
+        Ok(arity)
+    }
+
+    fn all_constructors(&self, cx: &MatchCheckCtx) -> Vec<Constructor> {
+        match self {
+            Constructor::Bool(_) => vec![Constructor::Bool(true), Constructor::Bool(false)],
+            Constructor::Tuple { .. } => vec![*self],
+            Constructor::Enum(e) => cx
+                .db
+                .enum_data(e.parent)
+                .variants
+                .iter()
+                .map(|(local_id, _)| {
+                    Constructor::Enum(EnumVariantId { parent: e.parent, local_id })
+                })
+                .collect(),
+        }
+    }
+}
+
+/// Returns the constructor for the given pattern. Should only return None
+/// in the case of a Wild pattern.
+fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Option<Constructor>> {
+    let res = match pat.as_pat(cx) {
+        Pat::Wild => None,
+        // FIXME somehow create the Tuple constructor with the proper arity. If there are
+        // ellipsis, the arity is not equal to the number of patterns.
+        Pat::Tuple { args: pats, ellipsis } if ellipsis.is_none() => {
+            Some(Constructor::Tuple { arity: pats.len() })
+        }
+        Pat::Lit(lit_expr) => match cx.body.exprs[lit_expr] {
+            Expr::Literal(Literal::Bool(val)) => Some(Constructor::Bool(val)),
+            _ => return Err(MatchCheckErr::NotImplemented),
+        },
+        Pat::TupleStruct { .. } | Pat::Path(_) | Pat::Record { .. } => {
+            let pat_id = pat.as_id().expect("we already know this pattern is not a wild");
+            let variant_id =
+                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::Unknown)?;
+            match variant_id {
+                VariantId::EnumVariantId(enum_variant_id) => {
+                    Some(Constructor::Enum(enum_variant_id))
+                }
+                _ => return Err(MatchCheckErr::NotImplemented),
+            }
+        }
+        _ => return Err(MatchCheckErr::NotImplemented),
+    };
+
+    Ok(res)
+}
+
+fn all_constructors_covered(
+    cx: &MatchCheckCtx,
+    constructor: &Constructor,
+    used_constructors: &[Constructor],
+) -> bool {
+    match constructor {
+        Constructor::Tuple { arity } => {
+            used_constructors.iter().any(|constructor| match constructor {
+                Constructor::Tuple { arity: used_arity } => arity == used_arity,
+                _ => false,
+            })
+        }
+        Constructor::Bool(_) => {
+            if used_constructors.is_empty() {
+                return false;
+            }
+
+            let covers_true =
+                used_constructors.iter().any(|c| matches!(c, Constructor::Bool(true)));
+            let covers_false =
+                used_constructors.iter().any(|c| matches!(c, Constructor::Bool(false)));
+
+            covers_true && covers_false
+        }
+        Constructor::Enum(e) => cx.db.enum_data(e.parent).variants.iter().all(|(id, _)| {
+            for constructor in used_constructors {
+                if let Constructor::Enum(e) = constructor {
+                    if id == e.local_id {
+                        return true;
+                    }
+                }
+            }
+
+            false
+        }),
+    }
+}
+
+fn enum_variant_matches(cx: &MatchCheckCtx, pat_id: PatId, enum_variant_id: EnumVariantId) -> bool {
+    Some(enum_variant_id.into()) == cx.infer.variant_resolution_for_pat(pat_id)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostics::tests::check_diagnostics;
+
+    #[test]
+    fn empty_tuple() {
+        check_diagnostics(
+            r#"
+fn main() {
+    match () { }
+        //^^ Missing match arm
+   match (()) { }
+       //^^^^ Missing match arm
+
+    match () { _ => (), }
+    match () { () => (), }
+    match (()) { (()) => (), }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn tuple_of_two_empty_tuple() {
+        check_diagnostics(
+            r#"
+fn main() {
+    match ((), ()) { }
+        //^^^^^^^^ Missing match arm
+
+    match ((), ()) { ((), ()) => (), }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn boolean() {
+        check_diagnostics(
+            r#"
+fn test_main() {
+    match false { }
+        //^^^^^ Missing match arm
+    match false { true => (), }
+        //^^^^^ Missing match arm
+    match (false, true) {}
+        //^^^^^^^^^^^^^ Missing match arm
+    match (false, true) { (true, true) => (), }
+        //^^^^^^^^^^^^^ Missing match arm
+    match (false, true) {
+        //^^^^^^^^^^^^^ Missing match arm
+        (false, true) => (),
+        (false, false) => (),
+        (true, false) => (),
+    }
+    match (false, true) { (true, _x) => (), }
+        //^^^^^^^^^^^^^ Missing match arm
+
+    match false { true => (), false => (), }
+    match (false, true) {
+        (false, _) => (),
+        (true, false) => (),
+        (_, true) => (),
+    }
+    match (false, true) {
+        (true, true) => (),
+        (true, false) => (),
+        (false, true) => (),
+        (false, false) => (),
+    }
+    match (false, true) {
+        (true, _x) => (),
+        (false, true) => (),
+        (false, false) => (),
+    }
+    match (false, true, false) {
+        (false, ..) => (),
+        (true, ..) => (),
+    }
+    match (false, true, false) {
+        (.., false) => (),
+        (.., true) => (),
+    }
+    match (false, true, false) { (..) => (), }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn tuple_of_tuple_and_bools() {
+        check_diagnostics(
+            r#"
+fn main() {
+    match (false, ((), false)) {}
+        //^^^^^^^^^^^^^^^^^^^^ Missing match arm
+    match (false, ((), false)) { (true, ((), true)) => (), }
+        //^^^^^^^^^^^^^^^^^^^^ Missing match arm
+    match (false, ((), false)) { (true, _) => (), }
+        //^^^^^^^^^^^^^^^^^^^^ Missing match arm
+
+    match (false, ((), false)) {
+        (true, ((), true)) => (),
+        (true, ((), false)) => (),
+        (false, ((), true)) => (),
+        (false, ((), false)) => (),
+    }
+    match (false, ((), false)) {
+        (true, ((), true)) => (),
+        (true, ((), false)) => (),
+        (false, _) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enums() {
+        check_diagnostics(
+            r#"
+enum Either { A, B, }
+
+fn main() {
+    match Either::A { }
+        //^^^^^^^^^ Missing match arm
+    match Either::B { Either::A => (), }
+        //^^^^^^^^^ Missing match arm
+
+    match &Either::B {
+        //^^^^^^^^^^ Missing match arm
+        Either::A => (),
+    }
+
+    match Either::B {
+        Either::A => (), Either::B => (),
+    }
+    match &Either::B {
+        Either::A => (), Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enum_containing_bool() {
+        check_diagnostics(
+            r#"
+enum Either { A(bool), B }
+
+fn main() {
+    match Either::B { }
+        //^^^^^^^^^ Missing match arm
+    match Either::B {
+        //^^^^^^^^^ Missing match arm
+        Either::A(true) => (), Either::B => ()
+    }
+
+    match Either::B {
+        Either::A(true) => (),
+        Either::A(false) => (),
+        Either::B => (),
+    }
+    match Either::B {
+        Either::B => (),
+        _ => (),
+    }
+    match Either::B {
+        Either::A(_) => (),
+        Either::B => (),
+    }
+
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn enum_different_sizes() {
+        check_diagnostics(
+            r#"
+enum Either { A(bool), B(bool, bool) }
+
+fn main() {
+    match Either::A(false) {
+        //^^^^^^^^^^^^^^^^ Missing match arm
+        Either::A(_) => (),
+        Either::B(false, _) => (),
+    }
+
+    match Either::A(false) {
+        Either::A(_) => (),
+        Either::B(true, _) => (),
+        Either::B(false, _) => (),
+    }
+    match Either::A(false) {
+        Either::A(true) | Either::A(false) => (),
+        Either::B(true, _) => (),
+        Either::B(false, _) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn tuple_of_enum_no_diagnostic() {
+        check_diagnostics(
+            r#"
+enum Either { A(bool), B(bool, bool) }
+enum Either2 { C, D }
+
+fn main() {
+    match (Either::A(false), Either2::C) {
+        (Either::A(true), _) | (Either::A(false), _) => (),
+        (Either::B(true, _), Either2::C) => (),
+        (Either::B(false, _), Either2::C) => (),
+        (Either::B(_, _), Either2::D) => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn mismatched_types() {
+        // Match statements with arms that don't match the
+        // expression pattern do not fire this diagnostic.
+        check_diagnostics(
+            r#"
+enum Either { A, B }
+enum Either2 { C, D }
+
+fn main() {
+    match Either::A {
+        Either2::C => (),
+        Either2::D => (),
+    }
+    match (true, false) {
+        (true, false, true) => (),
+        (true) => (),
+    }
+    match (0) { () => () }
+    match Unresolved::Bar { Unresolved::Baz => () }
+}
+        "#,
+        );
+    }
+
+    #[test]
+    fn malformed_match_arm_tuple_enum_missing_pattern() {
+        // We are testing to be sure we don't panic here when the match
+        // arm `Either::B` is missing its pattern.
+        check_diagnostics(
+            r#"
+enum Either { A, B(u32) }
+
+fn main() {
+    match Either::A {
+        Either::A => (),
+        Either::B() => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn expr_diverges() {
+        check_diagnostics(
+            r#"
+enum Either { A, B }
+
+fn main() {
+    match loop {} {
+        Either::A => (),
+        Either::B => (),
+    }
+    match loop {} {
+        Either::A => (),
+    }
+    match loop { break Foo::A } {
+        //^^^^^^^^^^^^^^^^^^^^^ Missing match arm
+        Either::A => (),
+    }
+    match loop { break Foo::A } {
+        Either::A => (),
+        Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn expr_partially_diverges() {
+        check_diagnostics(
+            r#"
+enum Either<T> { A(T), B }
+
+fn foo() -> Either<!> { Either::B }
+fn main() -> u32 {
+    match foo() {
+        Either::A(val) => val,
+        Either::B => 0,
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enum_record() {
+        check_diagnostics(
+            r#"
+enum Either { A { foo: bool }, B }
+
+fn main() {
+    let a = Either::A { foo: true };
+    match a { }
+        //^ Missing match arm
+    match a { Either::A { foo: true } => () }
+        //^ Missing match arm
+    match a {
+        Either::A { } => (),
+                //^^^ Missing structure fields:
+                //  | - foo
+        Either::B => (),
+    }
+    match a {
+        //^ Missing match arm
+        Either::A { } => (),
+    }           //^^^ Missing structure fields:
+                //  | - foo
+
+    match a {
+        Either::A { foo: true } => (),
+        Either::A { foo: false } => (),
+        Either::B => (),
+    }
+    match a {
+        Either::A { foo: _ } => (),
+        Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enum_record_fields_out_of_order() {
+        check_diagnostics(
+            r#"
+enum Either {
+    A { foo: bool, bar: () },
+    B,
+}
+
+fn main() {
+    let a = Either::A { foo: true, bar: () };
+    match a {
+        //^ Missing match arm
+        Either::A { bar: (), foo: false } => (),
+        Either::A { foo: true, bar: () } => (),
+    }
+
+    match a {
+        Either::A { bar: (), foo: false } => (),
+        Either::A { foo: true, bar: () } => (),
+        Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enum_record_ellipsis() {
+        check_diagnostics(
+            r#"
+enum Either {
+    A { foo: bool, bar: bool },
+    B,
+}
+
+fn main() {
+    let a = Either::B;
+    match a {
+        //^ Missing match arm
+        Either::A { foo: true, .. } => (),
+        Either::B => (),
+    }
+    match a {
+        //^ Missing match arm
+        Either::A { .. } => (),
+    }
+
+    match a {
+        Either::A { foo: true, .. } => (),
+        Either::A { foo: false, .. } => (),
+        Either::B => (),
+    }
+
+    match a {
+        Either::A { .. } => (),
+        Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn enum_tuple_partial_ellipsis() {
+        check_diagnostics(
+            r#"
+enum Either {
+    A(bool, bool, bool, bool),
+    B,
+}
+
+fn main() {
+    match Either::B {
+        //^^^^^^^^^ Missing match arm
+        Either::A(true, .., true) => (),
+        Either::A(true, .., false) => (),
+        Either::A(false, .., false) => (),
+        Either::B => (),
+    }
+    match Either::B {
+        //^^^^^^^^^ Missing match arm
+        Either::A(true, .., true) => (),
+        Either::A(true, .., false) => (),
+        Either::A(.., true) => (),
+        Either::B => (),
+    }
+
+    match Either::B {
+        Either::A(true, .., true) => (),
+        Either::A(true, .., false) => (),
+        Either::A(false, .., true) => (),
+        Either::A(false, .., false) => (),
+        Either::B => (),
+    }
+    match Either::B {
+        Either::A(true, .., true) => (),
+        Either::A(true, .., false) => (),
+        Either::A(.., true) => (),
+        Either::A(.., false) => (),
+        Either::B => (),
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn never() {
+        check_diagnostics(
+            r#"
+enum Never {}
+
+fn enum_(never: Never) {
+    match never {}
+}
+fn enum_ref(never: &Never) {
+    match never {}
+}
+fn bang(never: !) {
+    match never {}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn or_pattern_panic() {
+        check_diagnostics(
+            r#"
+pub enum Category { Infinity, Zero }
+
+fn panic(a: Category, b: Category) {
+    match (a, b) {
+        (Category::Zero | Category::Infinity, _) => (),
+        (_, Category::Zero | Category::Infinity) => (),
+    }
+
+    // FIXME: This is a false positive, but the code used to cause a panic in the match checker,
+    // so this acts as a regression test for that.
+    match (a, b) {
+        //^^^^^^ Missing match arm
+        (Category::Infinity, Category::Infinity) | (Category::Zero, Category::Zero) => (),
+        (Category::Infinity | Category::Zero, _) => (),
+    }
+}
+"#,
+        );
+    }
+
+    mod false_negatives {
+        //! The implementation of match checking here is a work in progress. As we roll this out, we
+        //! prefer false negatives to false positives (ideally there would be no false positives). This
+        //! test module should document known false negatives. Eventually we will have a complete
+        //! implementation of match checking and this module will be empty.
+        //!
+        //! The reasons for documenting known false negatives:
+        //!
+        //!   1. It acts as a backlog of work that can be done to improve the behavior of the system.
+        //!   2. It ensures the code doesn't panic when handling these cases.
+        use super::*;
+
+        #[test]
+        fn integers() {
+            // We don't currently check integer exhaustiveness.
+            check_diagnostics(
+                r#"
+fn main() {
+    match 5 {
+        10 => (),
+        11..20 => (),
+    }
+}
+"#,
+            );
+        }
+
+        #[test]
+        fn internal_or() {
+            // We do not currently handle patterns with internal `or`s.
+            check_diagnostics(
+                r#"
+fn main() {
+    enum Either { A(bool), B }
+    match Either::B {
+        Either::A(true | false) => (),
+    }
+}
+"#,
+            );
+        }
+
+        #[test]
+        fn tuple_of_bools_with_ellipsis_at_end_missing_arm() {
+            // We don't currently handle tuple patterns with ellipsis.
+            check_diagnostics(
+                r#"
+fn main() {
+    match (false, true, false) {
+        (false, ..) => (),
+    }
+}
+"#,
+            );
+        }
+
+        #[test]
+        fn tuple_of_bools_with_ellipsis_at_beginning_missing_arm() {
+            // We don't currently handle tuple patterns with ellipsis.
+            check_diagnostics(
+                r#"
+fn main() {
+    match (false, true, false) {
+        (.., false) => (),
+    }
+}
+"#,
+            );
+        }
+
+        #[test]
+        fn struct_missing_arm() {
+            // We don't currently handle structs.
+            check_diagnostics(
+                r#"
+struct Foo { a: bool }
+fn main(f: Foo) {
+    match f { Foo { a: true } => () }
+}
+"#,
+            );
+        }
+    }
+}
diff --git a/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs b/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
new file mode 100644
index 000000000..5cc76bdce
--- /dev/null
+++ b/crates/ra_hir_ty/src/diagnostics/unsafe_check.rs
@@ -0,0 +1,173 @@
+//! Provides validations for unsafe code. Currently checks if unsafe functions are missing
+//! unsafe blocks.
+
+use std::sync::Arc;
+
+use hir_def::{
+    body::Body,
+    expr::{Expr, ExprId, UnaryOp},
+    DefWithBodyId,
+};
+use hir_expand::diagnostics::DiagnosticSink;
+
+use crate::{
+    db::HirDatabase, diagnostics::MissingUnsafe, lower::CallableDefId, ApplicationTy,
+    InferenceResult, Ty, TypeCtor,
+};
+
+pub(super) struct UnsafeValidator<'a, 'b: 'a> {
+    owner: DefWithBodyId,
+    infer: Arc<InferenceResult>,
+    sink: &'a mut DiagnosticSink<'b>,
+}
+
+impl<'a, 'b> UnsafeValidator<'a, 'b> {
+    pub(super) fn new(
+        owner: DefWithBodyId,
+        infer: Arc<InferenceResult>,
+        sink: &'a mut DiagnosticSink<'b>,
+    ) -> UnsafeValidator<'a, 'b> {
+        UnsafeValidator { owner, infer, sink }
+    }
+
+    pub(super) fn validate_body(&mut self, db: &dyn HirDatabase) {
+        let def = self.owner.into();
+        let unsafe_expressions = unsafe_expressions(db, self.infer.as_ref(), def);
+        let is_unsafe = match self.owner {
+            DefWithBodyId::FunctionId(it) => db.function_data(it).is_unsafe,
+            DefWithBodyId::StaticId(_) | DefWithBodyId::ConstId(_) => false,
+        };
+        if is_unsafe
+            || unsafe_expressions
+                .iter()
+                .filter(|unsafe_expr| !unsafe_expr.inside_unsafe_block)
+                .count()
+                == 0
+        {
+            return;
+        }
+
+        let (_, body_source) = db.body_with_source_map(def);
+        for unsafe_expr in unsafe_expressions {
+            if !unsafe_expr.inside_unsafe_block {
+                if let Ok(in_file) = body_source.as_ref().expr_syntax(unsafe_expr.expr) {
+                    self.sink.push(MissingUnsafe { file: in_file.file_id, expr: in_file.value })
+                }
+            }
+        }
+    }
+}
+
+pub struct UnsafeExpr {
+    pub expr: ExprId,
+    pub inside_unsafe_block: bool,
+}
+
+pub fn unsafe_expressions(
+    db: &dyn HirDatabase,
+    infer: &InferenceResult,
+    def: DefWithBodyId,
+) -> Vec<UnsafeExpr> {
+    let mut unsafe_exprs = vec![];
+    let body = db.body(def);
+    walk_unsafe(&mut unsafe_exprs, db, infer, &body, body.body_expr, false);
+
+    unsafe_exprs
+}
+
+fn walk_unsafe(
+    unsafe_exprs: &mut Vec<UnsafeExpr>,
+    db: &dyn HirDatabase,
+    infer: &InferenceResult,
+    body: &Body,
+    current: ExprId,
+    inside_unsafe_block: bool,
+) {
+    let expr = &body.exprs[current];
+    match expr {
+        Expr::Call { callee, .. } => {
+            let ty = &infer[*callee];
+            if let &Ty::Apply(ApplicationTy {
+                ctor: TypeCtor::FnDef(CallableDefId::FunctionId(func)),
+                ..
+            }) = ty
+            {
+                if db.function_data(func).is_unsafe {
+                    unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
+                }
+            }
+        }
+        Expr::MethodCall { .. } => {
+            if infer
+                .method_resolution(current)
+                .map(|func| db.function_data(func).is_unsafe)
+                .unwrap_or(false)
+            {
+                unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
+            }
+        }
+        Expr::UnaryOp { expr, op: UnaryOp::Deref } => {
+            if let Ty::Apply(ApplicationTy { ctor: TypeCtor::RawPtr(..), .. }) = &infer[*expr] {
+                unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
+            }
+        }
+        Expr::Unsafe { body: child } => {
+            return walk_unsafe(unsafe_exprs, db, infer, body, *child, true);
+        }
+        _ => {}
+    }
+
+    expr.walk_child_exprs(|child| {
+        walk_unsafe(unsafe_exprs, db, infer, body, child, inside_unsafe_block);
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostics::tests::check_diagnostics;
+
+    #[test]
+    fn missing_unsafe_diagnostic_with_raw_ptr() {
+        check_diagnostics(
+            r#"
+fn main() {
+    let x = &5 as *const usize;
+    unsafe { let y = *x; }
+    let z = *x;
+}         //^^ This operation is unsafe and requires an unsafe function or block
+"#,
+        )
+    }
+
+    #[test]
+    fn missing_unsafe_diagnostic_with_unsafe_call() {
+        check_diagnostics(
+            r#"
+struct HasUnsafe;
+
+impl HasUnsafe {
+    unsafe fn unsafe_fn(&self) {
+        let x = &5 as *const usize;
+        let y = *x;
+    }
+}
+
+unsafe fn unsafe_fn() {
+    let x = &5 as *const usize;
+    let y = *x;
+}
+
+fn main() {
+    unsafe_fn();
+  //^^^^^^^^^^^ This operation is unsafe and requires an unsafe function or block
+    HasUnsafe.unsafe_fn();
+  //^^^^^^^^^^^^^^^^^^^^^ This operation is unsafe and requires an unsafe function or block
+    unsafe {
+        unsafe_fn();
+        HasUnsafe.unsafe_fn();
+    }
+}
+"#,
+        );
+    }
+}
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index b9c4d2e89..758d5f5ac 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -3,8 +3,8 @@
 use std::fmt;
 
 use crate::{
-    db::HirDatabase, utils::generics, ApplicationTy, CallableDef, FnSig, GenericPredicate,
-    Obligation, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
+    db::HirDatabase, utils::generics, ApplicationTy, CallableDefId, FnSig, GenericPredicate,
+    Obligation, OpaqueTyId, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
 };
 use hir_def::{
     find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId, AssocContainerId,
@@ -243,10 +243,17 @@ impl HirDisplay for ApplicationTy {
                     write!(f, ")")?;
                 }
             }
-            TypeCtor::FnPtr { .. } => {
-                let sig = FnSig::from_fn_ptr_substs(&self.parameters);
+            TypeCtor::FnPtr { is_varargs, .. } => {
+                let sig = FnSig::from_fn_ptr_substs(&self.parameters, is_varargs);
                 write!(f, "fn(")?;
                 f.write_joined(sig.params(), ", ")?;
+                if is_varargs {
+                    if sig.params().is_empty() {
+                        write!(f, "...")?;
+                    } else {
+                        write!(f, ", ...")?;
+                    }
+                }
                 write!(f, ")")?;
                 let ret = sig.ret();
                 if *ret != Ty::unit() {
@@ -256,9 +263,11 @@ impl HirDisplay for ApplicationTy {
             TypeCtor::FnDef(def) => {
                 let sig = f.db.callable_item_signature(def).subst(&self.parameters);
                 match def {
-                    CallableDef::FunctionId(ff) => write!(f, "fn {}", f.db.function_data(ff).name)?,
-                    CallableDef::StructId(s) => write!(f, "{}", f.db.struct_data(s).name)?,
-                    CallableDef::EnumVariantId(e) => {
+                    CallableDefId::FunctionId(ff) => {
+                        write!(f, "fn {}", f.db.function_data(ff).name)?
+                    }
+                    CallableDefId::StructId(s) => write!(f, "{}", f.db.struct_data(s).name)?,
+                    CallableDefId::EnumVariantId(e) => {
                         write!(f, "{}", f.db.enum_data(e.parent).variants[e.local_id].name)?
                     }
                 };
@@ -308,7 +317,6 @@ impl HirDisplay for ApplicationTy {
                 }
 
                 if self.parameters.len() > 0 {
-                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
                     let parameters_to_write =
                         if f.display_target.is_source_code() || f.omit_verbose_types() {
                             match self
@@ -319,20 +327,23 @@ impl HirDisplay for ApplicationTy {
                             {
                                 None => self.parameters.0.as_ref(),
                                 Some(default_parameters) => {
+                                    let mut default_from = 0;
                                     for (i, parameter) in self.parameters.iter().enumerate() {
                                         match (parameter, default_parameters.get(i)) {
                                             (&Ty::Unknown, _) | (_, None) => {
-                                                non_default_parameters.push(parameter.clone())
+                                                default_from = i + 1;
                                             }
-                                            (_, Some(default_parameter))
-                                                if parameter != default_parameter =>
-                                            {
-                                                non_default_parameters.push(parameter.clone())
+                                            (_, Some(default_parameter)) => {
+                                                let actual_default = default_parameter
+                                                    .clone()
+                                                    .subst(&self.parameters.prefix(i));
+                                                if parameter != &actual_default {
+                                                    default_from = i + 1;
+                                                }
                                             }
-                                            _ => (),
                                         }
                                     }
-                                    &non_default_parameters
+                                    &self.parameters.0[0..default_from]
                                 }
                             }
                         } else {
@@ -359,6 +370,21 @@ impl HirDisplay for ApplicationTy {
                     write!(f, ">")?;
                 }
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => {
+                let bounds = match opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                        let datas =
+                            f.db.return_type_impl_traits(func).expect("impl trait id without data");
+                        let data = (*datas)
+                            .as_ref()
+                            .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                        data.subst(&self.parameters)
+                    }
+                };
+                write!(f, "impl ")?;
+                write_bounds_like_dyn_trait(&bounds.value, f)?;
+                // FIXME: it would maybe be good to distinguish this from the alias type (when debug printing), and to show the substitution
+            }
             TypeCtor::Closure { .. } => {
                 let sig = self.parameters[0].callable_sig(f.db);
                 if let Some(sig) = sig {
@@ -427,14 +453,24 @@ impl HirDisplay for Ty {
                 }
             }
             Ty::Bound(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                match self {
-                    Ty::Dyn(_) => write!(f, "dyn ")?,
-                    Ty::Opaque(_) => write!(f, "impl ")?,
-                    _ => unreachable!(),
-                };
+            Ty::Dyn(predicates) => {
+                write!(f, "dyn ")?;
                 write_bounds_like_dyn_trait(predicates, f)?;
             }
+            Ty::Opaque(opaque_ty) => {
+                let bounds = match opaque_ty.opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                        let datas =
+                            f.db.return_type_impl_traits(func).expect("impl trait id without data");
+                        let data = (*datas)
+                            .as_ref()
+                            .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                        data.subst(&opaque_ty.parameters)
+                    }
+                };
+                write!(f, "impl ")?;
+                write_bounds_like_dyn_trait(&bounds.value, f)?;
+            }
             Ty::Unknown => write!(f, "{{unknown}}")?,
             Ty::Infer(..) => write!(f, "_")?,
         }
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index dc77e88e5..28f32a0a4 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -18,8 +18,6 @@ use std::mem;
 use std::ops::Index;
 use std::sync::Arc;
 
-use rustc_hash::FxHashMap;
-
 use hir_def::{
     body::Body,
     data::{ConstData, FunctionData, StaticData},
@@ -28,19 +26,20 @@ use hir_def::{
     path::{path, Path},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{Mutability, TypeRef},
-    AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, FunctionId, TraitId, TypeAliasId,
-    VariantId,
+    AdtId, AssocItemId, DefWithBodyId, EnumVariantId, FieldId, FunctionId, Lookup, TraitId,
+    TypeAliasId, VariantId,
 };
 use hir_expand::{diagnostics::DiagnosticSink, name::name};
 use ra_arena::map::ArenaMap;
 use ra_prof::profile;
 use ra_syntax::SmolStr;
+use rustc_hash::FxHashMap;
+use stdx::impl_from;
 
 use super::{
     primitive::{FloatTy, IntTy},
     traits::{Guidance, Obligation, ProjectionPredicate, Solution},
-    ApplicationTy, GenericPredicate, InEnvironment, ProjectionTy, Substs, TraitEnvironment,
-    TraitRef, Ty, TypeCtor, TypeWalk, Uncertain,
+    InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 use crate::{
     db::HirDatabase, infer::diagnostics::InferenceDiagnostic, lower::ImplTraitLoweringMode,
@@ -85,8 +84,7 @@ enum ExprOrPatId {
     ExprId(ExprId),
     PatId(PatId),
 }
-
-impl_froms!(ExprOrPatId: ExprId, PatId);
+impl_from!(ExprId, PatId for ExprOrPatId);
 
 /// Binding modes inferred for patterns.
 /// https://doc.rust-lang.org/reference/patterns.html#binding-modes
@@ -170,7 +168,7 @@ impl InferenceResult {
     pub fn add_diagnostics(
         &self,
         db: &dyn HirDatabase,
-        owner: FunctionId,
+        owner: DefWithBodyId,
         sink: &mut DiagnosticSink,
     ) {
         self.diagnostics.iter().for_each(|it| it.add_to(db, owner, sink))
@@ -312,12 +310,6 @@ impl<'a> InferenceContext<'a> {
     fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
         match ty {
             Ty::Unknown => self.table.new_type_var(),
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(Uncertain::Unknown), .. }) => {
-                self.table.new_integer_var()
-            }
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(Uncertain::Unknown), .. }) => {
-                self.table.new_float_var()
-            }
             _ => ty,
         }
     }
@@ -383,36 +375,21 @@ impl<'a> InferenceContext<'a> {
     ) -> Ty {
         match assoc_ty {
             Some(res_assoc_ty) => {
-                // FIXME:
-                // Check if inner_ty is is `impl Trait` and contained input TypeAlias id
-                // this is a workaround while Chalk assoc type projection doesn't always work yet,
-                // but once that is fixed I don't think we should keep this
-                // (we'll probably change how associated types are resolved anyway)
-                if let Ty::Opaque(ref predicates) = inner_ty {
-                    for p in predicates.iter() {
-                        if let GenericPredicate::Projection(projection) = p {
-                            if projection.projection_ty.associated_ty == res_assoc_ty {
-                                if let ty_app!(_, params) = &projection.ty {
-                                    if params.len() == 0 {
-                                        return projection.ty.clone();
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-
+                let trait_ = match res_assoc_ty.lookup(self.db.upcast()).container {
+                    hir_def::AssocContainerId::TraitId(trait_) => trait_,
+                    _ => panic!("resolve_associated_type called with non-associated type"),
+                };
                 let ty = self.table.new_type_var();
-                let builder = Substs::build_for_def(self.db, res_assoc_ty)
+                let substs = Substs::build_for_def(self.db, res_assoc_ty)
                     .push(inner_ty)
-                    .fill(params.iter().cloned());
+                    .fill(params.iter().cloned())
+                    .build();
+                let trait_ref = TraitRef { trait_, substs: substs.clone() };
                 let projection = ProjectionPredicate {
                     ty: ty.clone(),
-                    projection_ty: ProjectionTy {
-                        associated_ty: res_assoc_ty,
-                        parameters: builder.build(),
-                    },
+                    projection_ty: ProjectionTy { associated_ty: res_assoc_ty, parameters: substs },
                 };
+                self.obligations.push(Obligation::Trait(trait_ref));
                 self.obligations.push(Obligation::Projection(projection));
                 self.resolve_ty_as_possible(ty)
             }
@@ -458,13 +435,13 @@ impl<'a> InferenceContext<'a> {
             };
         return match resolution {
             TypeNs::AdtId(AdtId::StructId(strukt)) => {
-                let substs = Ty::substs_from_path(&ctx, path, strukt.into());
+                let substs = Ty::substs_from_path(&ctx, path, strukt.into(), true);
                 let ty = self.db.ty(strukt.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
                 forbid_unresolved_segments((ty, Some(strukt.into())), unresolved)
             }
             TypeNs::EnumVariantId(var) => {
-                let substs = Ty::substs_from_path(&ctx, path, var.into());
+                let substs = Ty::substs_from_path(&ctx, path, var.into(), true);
                 let ty = self.db.ty(var.parent.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
                 forbid_unresolved_segments((ty, Some(var.into())), unresolved)
@@ -581,13 +558,13 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
-        let path = path![std::iter::IntoIterator];
+        let path = path![core::iter::IntoIterator];
         let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
         self.db.trait_data(trait_).associated_type_by_name(&name![Item])
     }
 
     fn resolve_ops_try_ok(&self) -> Option<TypeAliasId> {
-        let path = path![std::ops::Try];
+        let path = path![core::ops::Try];
         let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
         self.db.trait_data(trait_).associated_type_by_name(&name![Ok])
     }
@@ -613,37 +590,37 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn resolve_range_full(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeFull];
+        let path = path![core::ops::RangeFull];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range(&self) -> Option<AdtId> {
-        let path = path![std::ops::Range];
+        let path = path![core::ops::Range];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_inclusive(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeInclusive];
+        let path = path![core::ops::RangeInclusive];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_from(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeFrom];
+        let path = path![core::ops::RangeFrom];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_to(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeTo];
+        let path = path![core::ops::RangeTo];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_to_inclusive(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeToInclusive];
+        let path = path![core::ops::RangeToInclusive];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
@@ -683,8 +660,8 @@ impl InferTy {
     fn fallback_value(self) -> Ty {
         match self {
             InferTy::TypeVar(..) => Ty::Unknown,
-            InferTy::IntVar(..) => Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::i32()))),
-            InferTy::FloatVar(..) => Ty::simple(TypeCtor::Float(Uncertain::Known(FloatTy::f64()))),
+            InferTy::IntVar(..) => Ty::simple(TypeCtor::Int(IntTy::i32())),
+            InferTy::FloatVar(..) => Ty::simple(TypeCtor::Float(FloatTy::f64())),
             InferTy::MaybeNeverTypeVar(..) => Ty::simple(TypeCtor::Never),
         }
     }
@@ -783,7 +760,7 @@ impl std::ops::BitOrAssign for Diverges {
 }
 
 mod diagnostics {
-    use hir_def::{expr::ExprId, FunctionId};
+    use hir_def::{expr::ExprId, DefWithBodyId};
     use hir_expand::diagnostics::DiagnosticSink;
 
     use crate::{
@@ -801,17 +778,17 @@ mod diagnostics {
         pub(super) fn add_to(
             &self,
             db: &dyn HirDatabase,
-            owner: FunctionId,
+            owner: DefWithBodyId,
             sink: &mut DiagnosticSink,
         ) {
             match self {
                 InferenceDiagnostic::NoSuchField { expr, field } => {
-                    let (_, source_map) = db.body_with_source_map(owner.into());
+                    let (_, source_map) = db.body_with_source_map(owner);
                     let field = source_map.field_syntax(*expr, *field);
                     sink.push(NoSuchField { file: field.file_id, field: field.value })
                 }
                 InferenceDiagnostic::BreakOutsideOfLoop { expr } => {
-                    let (_, source_map) = db.body_with_source_map(owner.into());
+                    let (_, source_map) = db.body_with_source_map(owner);
                     let ptr = source_map
                         .expr_syntax(*expr)
                         .expect("break outside of loop in synthetic syntax");
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 4a98e2deb..731b062c2 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -10,15 +10,15 @@ use hir_def::{
     resolver::resolver_for_expr,
     AdtId, AssocContainerId, FieldId, Lookup,
 };
-use hir_expand::name::Name;
+use hir_expand::name::{name, Name};
 use ra_syntax::ast::RangeOp;
 
 use crate::{
     autoderef, method_resolution, op,
-    traits::InEnvironment,
+    traits::{FnTrait, InEnvironment},
     utils::{generics, variant_data, Generics},
-    ApplicationTy, Binders, CallableDef, InferTy, IntTy, Mutability, Obligation, Rawness, Substs,
-    TraitRef, Ty, TypeCtor, Uncertain,
+    ApplicationTy, Binders, CallableDefId, InferTy, IntTy, Mutability, Obligation, Rawness, Substs,
+    TraitRef, Ty, TypeCtor,
 };
 
 use super::{
@@ -63,6 +63,56 @@ impl<'a> InferenceContext<'a> {
         self.resolve_ty_as_possible(ty)
     }
 
+    fn callable_sig_from_fn_trait(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> {
+        let krate = self.resolver.krate()?;
+        let fn_once_trait = FnTrait::FnOnce.get_id(self.db, krate)?;
+        let output_assoc_type =
+            self.db.trait_data(fn_once_trait).associated_type_by_name(&name![Output])?;
+        let generic_params = generics(self.db.upcast(), fn_once_trait.into());
+        if generic_params.len() != 2 {
+            return None;
+        }
+
+        let mut param_builder = Substs::builder(num_args);
+        let mut arg_tys = vec![];
+        for _ in 0..num_args {
+            let arg = self.table.new_type_var();
+            param_builder = param_builder.push(arg.clone());
+            arg_tys.push(arg);
+        }
+        let parameters = param_builder.build();
+        let arg_ty = Ty::Apply(ApplicationTy {
+            ctor: TypeCtor::Tuple { cardinality: num_args as u16 },
+            parameters,
+        });
+        let substs =
+            Substs::build_for_generics(&generic_params).push(ty.clone()).push(arg_ty).build();
+
+        let trait_env = Arc::clone(&self.trait_env);
+        let implements_fn_trait =
+            Obligation::Trait(TraitRef { trait_: fn_once_trait, substs: substs.clone() });
+        let goal = self.canonicalizer().canonicalize_obligation(InEnvironment {
+            value: implements_fn_trait.clone(),
+            environment: trait_env,
+        });
+        if self.db.trait_solve(krate, goal.value).is_some() {
+            self.obligations.push(implements_fn_trait);
+            let output_proj_ty =
+                crate::ProjectionTy { associated_ty: output_assoc_type, parameters: substs };
+            let return_ty = self.normalize_projection_ty(output_proj_ty);
+            Some((arg_tys, return_ty))
+        } else {
+            None
+        }
+    }
+
+    pub fn callable_sig(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> {
+        match ty.callable_sig(self.db) {
+            Some(sig) => Some((sig.params().to_vec(), sig.ret().clone())),
+            None => self.callable_sig_from_fn_trait(ty, num_args),
+        }
+    }
+
     fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
         let body = Arc::clone(&self.body); // avoid borrow checker problem
         let ty = match &body[tgt_expr] {
@@ -90,6 +140,7 @@ impl<'a> InferenceContext<'a> {
                 // FIXME: Breakable block inference
                 self.infer_block(statements, *tail, expected)
             }
+            Expr::Unsafe { body } => self.infer_expr(*body, expected),
             Expr::TryBlock { body } => {
                 let _inner = self.infer_expr(*body, expected);
                 // FIXME should be std::result::Result<{inner}, _>
@@ -169,7 +220,7 @@ impl<'a> InferenceContext<'a> {
                 };
                 sig_tys.push(ret_ty.clone());
                 let sig_ty = Ty::apply(
-                    TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
+                    TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1, is_varargs: false },
                     Substs(sig_tys.clone().into()),
                 );
                 let closure_ty =
@@ -198,14 +249,23 @@ impl<'a> InferenceContext<'a> {
             }
             Expr::Call { callee, args } => {
                 let callee_ty = self.infer_expr(*callee, &Expectation::none());
-                let (param_tys, ret_ty) = match callee_ty.callable_sig(self.db) {
-                    Some(sig) => (sig.params().to_vec(), sig.ret().clone()),
-                    None => {
-                        // Not callable
-                        // FIXME: report an error
-                        (Vec::new(), Ty::Unknown)
-                    }
-                };
+                let canonicalized = self.canonicalizer().canonicalize_ty(callee_ty.clone());
+                let mut derefs = autoderef(
+                    self.db,
+                    self.resolver.krate(),
+                    InEnvironment {
+                        value: canonicalized.value.clone(),
+                        environment: self.trait_env.clone(),
+                    },
+                );
+                let (param_tys, ret_ty): (Vec<Ty>, Ty) = derefs
+                    .find_map(|callee_deref_ty| {
+                        self.callable_sig(
+                            &canonicalized.decanonicalize_ty(callee_deref_ty.value),
+                            args.len(),
+                        )
+                    })
+                    .unwrap_or((Vec::new(), Ty::Unknown));
                 self.register_obligations_for_call(&callee_ty);
                 self.check_call_arguments(args, &param_tys);
                 self.normalize_associated_types_in(ret_ty)
@@ -345,8 +405,15 @@ impl<'a> InferenceContext<'a> {
                                     .subst(&a_ty.parameters)
                             })
                         }
-                        // FIXME:
-                        TypeCtor::Adt(AdtId::UnionId(_)) => None,
+                        TypeCtor::Adt(AdtId::UnionId(u)) => {
+                            self.db.union_data(u).variant_data.field(name).map(|local_id| {
+                                let field = FieldId { parent: u.into(), local_id };
+                                self.write_field_resolution(tgt_expr, field);
+                                self.db.field_types(u.into())[field.local_id]
+                                    .clone()
+                                    .subst(&a_ty.parameters)
+                            })
+                        }
                         _ => None,
                     },
                     _ => None,
@@ -426,15 +493,7 @@ impl<'a> InferenceContext<'a> {
                         match &inner_ty {
                             // Fast path for builtins
                             Ty::Apply(ApplicationTy {
-                                ctor:
-                                    TypeCtor::Int(Uncertain::Known(IntTy {
-                                        signedness: Signedness::Signed,
-                                        ..
-                                    })),
-                                ..
-                            })
-                            | Ty::Apply(ApplicationTy {
-                                ctor: TypeCtor::Int(Uncertain::Unknown),
+                                ctor: TypeCtor::Int(IntTy { signedness: Signedness::Signed, .. }),
                                 ..
                             })
                             | Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(_), .. })
@@ -577,9 +636,7 @@ impl<'a> InferenceContext<'a> {
                         );
                         self.infer_expr(
                             *repeat,
-                            &Expectation::has_type(Ty::simple(TypeCtor::Int(Uncertain::Known(
-                                IntTy::usize(),
-                            )))),
+                            &Expectation::has_type(Ty::simple(TypeCtor::Int(IntTy::usize()))),
                         );
                     }
                 }
@@ -592,13 +649,19 @@ impl<'a> InferenceContext<'a> {
                     Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
                 }
                 Literal::ByteString(..) => {
-                    let byte_type = Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::u8())));
+                    let byte_type = Ty::simple(TypeCtor::Int(IntTy::u8()));
                     let array_type = Ty::apply_one(TypeCtor::Array, byte_type);
                     Ty::apply_one(TypeCtor::Ref(Mutability::Shared), array_type)
                 }
                 Literal::Char(..) => Ty::simple(TypeCtor::Char),
-                Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int((*ty).into())),
-                Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float((*ty).into())),
+                Literal::Int(_v, ty) => match ty {
+                    Some(int_ty) => Ty::simple(TypeCtor::Int((*int_ty).into())),
+                    None => self.table.new_integer_var(),
+                },
+                Literal::Float(_v, ty) => match ty {
+                    Some(float_ty) => Ty::simple(TypeCtor::Float((*float_ty).into())),
+                    None => self.table.new_float_var(),
+                },
             },
         };
         // use a new type variable if we got Ty::Unknown here
@@ -727,11 +790,7 @@ impl<'a> InferenceContext<'a> {
         for &check_closures in &[false, true] {
             let param_iter = param_tys.iter().cloned().chain(repeat(Ty::Unknown));
             for (&arg, param_ty) in args.iter().zip(param_iter) {
-                let is_closure = match &self.body[arg] {
-                    Expr::Lambda { .. } => true,
-                    _ => false,
-                };
-
+                let is_closure = matches!(&self.body[arg], Expr::Lambda { .. });
                 if is_closure != check_closures {
                     continue;
                 }
@@ -795,7 +854,7 @@ impl<'a> InferenceContext<'a> {
                 }
                 // add obligation for trait implementation, if this is a trait method
                 match def {
-                    CallableDef::FunctionId(f) => {
+                    CallableDefId::FunctionId(f) => {
                         if let AssocContainerId::TraitId(trait_) =
                             f.lookup(self.db.upcast()).container
                         {
@@ -806,7 +865,7 @@ impl<'a> InferenceContext<'a> {
                             self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
                         }
                     }
-                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {}
+                    CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {}
                 }
             }
         }
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 4006f595d..4dd4f9802 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -4,7 +4,7 @@ use std::iter::repeat;
 use std::sync::Arc;
 
 use hir_def::{
-    expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
+    expr::{BindingAnnotation, Expr, Literal, Pat, PatId, RecordFieldPat},
     path::Path,
     type_ref::Mutability,
     FieldId,
@@ -90,18 +90,7 @@ impl<'a> InferenceContext<'a> {
     ) -> Ty {
         let body = Arc::clone(&self.body); // avoid borrow checker problem
 
-        let is_non_ref_pat = match &body[pat] {
-            Pat::Tuple { .. }
-            | Pat::Or(..)
-            | Pat::TupleStruct { .. }
-            | Pat::Record { .. }
-            | Pat::Range { .. }
-            | Pat::Slice { .. } => true,
-            // FIXME: Path/Lit might actually evaluate to ref, but inference is unimplemented.
-            Pat::Path(..) | Pat::Lit(..) => true,
-            Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Missing => false,
-        };
-        if is_non_ref_pat {
+        if is_non_ref_pat(&body, pat) {
             while let Some((inner, mutability)) = expected.as_reference() {
                 expected = inner;
                 default_bm = match default_bm {
@@ -195,7 +184,7 @@ impl<'a> InferenceContext<'a> {
                 self.write_pat_ty(pat, bound_ty);
                 return inner_ty;
             }
-            Pat::Slice { prefix, slice: _slice, suffix } => {
+            Pat::Slice { prefix, slice, suffix } => {
                 let (container_ty, elem_ty) = match &expected {
                     ty_app!(TypeCtor::Array, st) => (TypeCtor::Array, st.as_single().clone()),
                     ty_app!(TypeCtor::Slice, st) => (TypeCtor::Slice, st.as_single().clone()),
@@ -206,7 +195,12 @@ impl<'a> InferenceContext<'a> {
                     self.infer_pat(*pat_id, &elem_ty, default_bm);
                 }
 
-                Ty::apply_one(container_ty, elem_ty)
+                let pat_ty = Ty::apply_one(container_ty, elem_ty);
+                if let Some(slice_pat_id) = slice {
+                    self.infer_pat(*slice_pat_id, &pat_ty, default_bm);
+                }
+
+                pat_ty
             }
             Pat::Wild => expected.clone(),
             Pat::Range { start, end } => {
@@ -227,3 +221,21 @@ impl<'a> InferenceContext<'a> {
         ty
     }
 }
+
+fn is_non_ref_pat(body: &hir_def::body::Body, pat: PatId) -> bool {
+    match &body[pat] {
+        Pat::Tuple { .. }
+        | Pat::TupleStruct { .. }
+        | Pat::Record { .. }
+        | Pat::Range { .. }
+        | Pat::Slice { .. } => true,
+        Pat::Or(pats) => pats.iter().all(|p| is_non_ref_pat(body, *p)),
+        // FIXME: Path/Lit might actually evaluate to ref, but inference is unimplemented.
+        Pat::Path(..) => true,
+        Pat::Lit(expr) => match body[*expr] {
+            Expr::Literal(Literal::String(..)) => false,
+            _ => true,
+        },
+        Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Missing => false,
+    }
+}
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 1c2e56fb0..80d7ed10e 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -81,7 +81,7 @@ impl<'a> InferenceContext<'a> {
                 let generics = crate::utils::generics(self.db.upcast(), impl_id.into());
                 let substs = Substs::type_params_for_generics(&generics);
                 let ty = self.db.impl_self_ty(impl_id).subst(&substs);
-                if let Some((AdtId::StructId(struct_id), _)) = ty.as_adt() {
+                if let Some((AdtId::StructId(struct_id), substs)) = ty.as_adt() {
                     let ty = self.db.value_ty(struct_id.into()).subst(&substs);
                     return Some(ty);
                 } else {
@@ -95,7 +95,7 @@ impl<'a> InferenceContext<'a> {
         // self_subst is just for the parent
         let parent_substs = self_subst.unwrap_or_else(Substs::empty);
         let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver);
-        let substs = Ty::substs_from_path(&ctx, path, typable);
+        let substs = Ty::substs_from_path(&ctx, path, typable, true);
         let full_substs = Substs::builder(substs.len())
             .use_parent_substs(&parent_substs)
             .fill(substs.0[parent_substs.len()..].iter().cloned())
@@ -141,6 +141,7 @@ impl<'a> InferenceContext<'a> {
                     def,
                     resolved_segment,
                     remaining_segments_for_ty,
+                    true,
                 );
                 if let Ty::Unknown = ty {
                     return None;
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index 269495ca0..2e895d911 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -9,7 +9,7 @@ use test_utils::mark;
 use super::{InferenceContext, Obligation};
 use crate::{
     BoundVar, Canonical, DebruijnIndex, GenericPredicate, InEnvironment, InferTy, Substs, Ty,
-    TypeCtor, TypeWalk,
+    TyKind, TypeCtor, TypeWalk,
 };
 
 impl<'a> InferenceContext<'a> {
@@ -86,10 +86,20 @@ where
     }
 
     fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
-        Canonicalized {
-            value: Canonical { value: result, num_vars: self.free_vars.len() },
-            free_vars: self.free_vars,
-        }
+        let kinds = self
+            .free_vars
+            .iter()
+            .map(|v| match v {
+                // mapping MaybeNeverTypeVar to the same kind as general ones
+                // should be fine, because as opposed to int or float type vars,
+                // they don't restrict what kind of type can go into them, they
+                // just affect fallback.
+                InferTy::TypeVar(_) | InferTy::MaybeNeverTypeVar(_) => TyKind::General,
+                InferTy::IntVar(_) => TyKind::Integer,
+                InferTy::FloatVar(_) => TyKind::Float,
+            })
+            .collect();
+        Canonicalized { value: Canonical { value: result, kinds }, free_vars: self.free_vars }
     }
 
     pub(crate) fn canonicalize_ty(mut self, ty: Ty) -> Canonicalized<Ty> {
@@ -131,26 +141,41 @@ impl<T> Canonicalized<T> {
         ty
     }
 
-    pub fn apply_solution(&self, ctx: &mut InferenceContext<'_>, solution: Canonical<Vec<Ty>>) {
+    pub fn apply_solution(&self, ctx: &mut InferenceContext<'_>, solution: Canonical<Substs>) {
         // the solution may contain new variables, which we need to convert to new inference vars
-        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.table.new_type_var()).collect());
+        let new_vars = Substs(
+            solution
+                .kinds
+                .iter()
+                .map(|k| match k {
+                    TyKind::General => ctx.table.new_type_var(),
+                    TyKind::Integer => ctx.table.new_integer_var(),
+                    TyKind::Float => ctx.table.new_float_var(),
+                })
+                .collect(),
+        );
         for (i, ty) in solution.value.into_iter().enumerate() {
             let var = self.free_vars[i];
             // eagerly replace projections in the type; we may be getting types
             // e.g. from where clauses where this hasn't happened yet
-            let ty = ctx.normalize_associated_types_in(ty.subst_bound_vars(&new_vars));
+            let ty = ctx.normalize_associated_types_in(ty.clone().subst_bound_vars(&new_vars));
             ctx.table.unify(&Ty::Infer(var), &ty);
         }
     }
 }
 
-pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
+pub fn unify(tys: &Canonical<(Ty, Ty)>) -> Option<Substs> {
     let mut table = InferenceTable::new();
-    let num_vars = ty1.num_vars.max(ty2.num_vars);
-    let vars =
-        Substs::builder(num_vars).fill(std::iter::repeat_with(|| table.new_type_var())).build();
-    let ty1_with_vars = ty1.value.clone().subst_bound_vars(&vars);
-    let ty2_with_vars = ty2.value.clone().subst_bound_vars(&vars);
+    let vars = Substs(
+        tys.kinds
+            .iter()
+            // we always use type vars here because we want everything to
+            // fallback to Unknown in the end (kind of hacky, as below)
+            .map(|_| table.new_type_var())
+            .collect(),
+    );
+    let ty1_with_vars = tys.value.0.clone().subst_bound_vars(&vars);
+    let ty2_with_vars = tys.value.1.clone().subst_bound_vars(&vars);
     if !table.unify(&ty1_with_vars, &ty2_with_vars) {
         return None;
     }
@@ -162,7 +187,7 @@ pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
         }
     }
     Some(
-        Substs::builder(ty1.num_vars)
+        Substs::builder(tys.kinds.len())
             .fill(vars.iter().map(|v| table.resolve_ty_completely(v.clone())))
             .build(),
     )
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 9fa8d3bdc..0ef5ca78f 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -6,25 +6,6 @@ macro_rules! eprintln {
     ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
 }
 
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-            $($(
-                impl From<$sv> for $e {
-                    fn from(it: $sv) -> $e {
-                        $e::$v($v::$sv(it))
-                    }
-                }
-            )*)?
-        )*
-    }
-}
-
 mod autoderef;
 pub mod primitive;
 pub mod traits;
@@ -32,21 +13,18 @@ pub mod method_resolution;
 mod op;
 mod lower;
 pub(crate) mod infer;
-pub mod display;
 pub(crate) mod utils;
+
+pub mod display;
 pub mod db;
 pub mod diagnostics;
-pub mod expr;
 
 #[cfg(test)]
 mod tests;
 #[cfg(test)]
 mod test_db;
-mod _match;
 
-use std::ops::Deref;
-use std::sync::Arc;
-use std::{iter, mem};
+use std::{iter, mem, ops::Deref, sync::Arc};
 
 use hir_def::{
     expr::ExprId,
@@ -54,18 +32,19 @@ use hir_def::{
     AdtId, AssocContainerId, DefWithBodyId, GenericDefId, HasModule, Lookup, TraitId, TypeAliasId,
     TypeParamId,
 };
-use ra_db::{impl_intern_key, salsa, CrateId};
+use itertools::Itertools;
+use ra_db::{salsa, CrateId};
 
 use crate::{
     db::HirDatabase,
-    primitive::{FloatTy, IntTy, Uncertain},
+    display::HirDisplay,
+    primitive::{FloatTy, IntTy},
     utils::{generics, make_mut_slice, Generics},
 };
-use display::HirDisplay;
 
 pub use autoderef::autoderef;
 pub use infer::{InferTy, InferenceResult};
-pub use lower::CallableDef;
+pub use lower::CallableDefId;
 pub use lower::{
     associated_type_shorthand_candidates, callable_item_sig, ImplTraitLoweringMode, TyDefId,
     TyLoweringContext, ValueTyDefId,
@@ -87,10 +66,10 @@ pub enum TypeCtor {
     Char,
 
     /// A primitive integer type. For example, `i32`.
-    Int(Uncertain<IntTy>),
+    Int(IntTy),
 
     /// A primitive floating-point type. For example, `f64`.
-    Float(Uncertain<FloatTy>),
+    Float(FloatTy),
 
     /// Structures, enumerations and unions.
     Adt(AdtId),
@@ -123,7 +102,7 @@ pub enum TypeCtor {
     /// fn foo() -> i32 { 1 }
     /// let bar = foo; // bar: fn() -> i32 {foo}
     /// ```
-    FnDef(CallableDef),
+    FnDef(CallableDefId),
 
     /// A pointer to a function.  Written as `fn() -> i32`.
     ///
@@ -133,7 +112,8 @@ pub enum TypeCtor {
     /// fn foo() -> i32 { 1 }
     /// let bar: fn() -> i32 = foo;
     /// ```
-    FnPtr { num_args: u16 },
+    // FIXME make this a Ty variant like in Chalk
+    FnPtr { num_args: u16, is_varargs: bool },
 
     /// The never type `!`.
     Never,
@@ -147,6 +127,12 @@ pub enum TypeCtor {
     /// an **application type** like `(Iterator::Item)<T>`.
     AssociatedType(TypeAliasId),
 
+    /// This represents a placeholder for an opaque type in situations where we
+    /// don't know the hidden type (i.e. currently almost always). This is
+    /// analogous to the `AssociatedType` type constructor. As with that one,
+    /// these are only produced by Chalk.
+    OpaqueType(OpaqueTyId),
+
     /// The type of a specific closure.
     ///
     /// The closure signature is stored in a `FnPtr` type in the first type
@@ -154,19 +140,6 @@ pub enum TypeCtor {
     Closure { def: DefWithBodyId, expr: ExprId },
 }
 
-/// This exists just for Chalk, because Chalk just has a single `StructId` where
-/// we have different kinds of ADTs, primitive types and special type
-/// constructors like tuples and function pointers.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
-pub struct TypeCtorId(salsa::InternId);
-impl_intern_key!(TypeCtorId);
-
-/// This exists just for Chalk, because Chalk just has a single `FnDefId` where
-/// we have different IDs for struct and enum variant constructors.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
-pub struct CallableDefId(salsa::InternId);
-impl_intern_key!(CallableDefId);
-
 impl TypeCtor {
     pub fn num_ty_params(self, db: &dyn HirDatabase) -> usize {
         match self {
@@ -194,7 +167,15 @@ impl TypeCtor {
                 let generic_params = generics(db.upcast(), type_alias.into());
                 generic_params.len()
             }
-            TypeCtor::FnPtr { num_args } => num_args as usize + 1,
+            TypeCtor::OpaqueType(opaque_ty_id) => {
+                match opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, _) => {
+                        let generic_params = generics(db.upcast(), func.into());
+                        generic_params.len()
+                    }
+                }
+            }
+            TypeCtor::FnPtr { num_args, is_varargs: _ } => num_args as usize + 1,
             TypeCtor::Tuple { cardinality } => cardinality as usize,
         }
     }
@@ -220,6 +201,11 @@ impl TypeCtor {
             TypeCtor::AssociatedType(type_alias) => {
                 Some(type_alias.lookup(db.upcast()).module(db.upcast()).krate)
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => match opaque_ty_id {
+                OpaqueTyId::ReturnTypeImplTrait(func, _) => {
+                    Some(func.lookup(db.upcast()).module(db.upcast()).krate)
+                }
+            },
         }
     }
 
@@ -241,6 +227,7 @@ impl TypeCtor {
             TypeCtor::Adt(adt) => Some(adt.into()),
             TypeCtor::FnDef(callable) => Some(callable.into()),
             TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
+            TypeCtor::OpaqueType(_impl_trait_id) => None,
         }
     }
 }
@@ -254,6 +241,12 @@ pub struct ApplicationTy {
     pub parameters: Substs,
 }
 
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct OpaqueTy {
+    pub opaque_ty_id: OpaqueTyId,
+    pub parameters: Substs,
+}
+
 /// A "projection" type corresponds to an (unnormalized)
 /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
 /// trait and all its parameters are fully known.
@@ -308,6 +301,12 @@ pub enum Ty {
     /// trait and all its parameters are fully known.
     Projection(ProjectionTy),
 
+    /// An opaque type (`impl Trait`).
+    ///
+    /// This is currently only used for return type impl trait; each instance of
+    /// `impl Trait` in a return type gets its own ID.
+    Opaque(OpaqueTy),
+
     /// A placeholder for a type parameter; for example, `T` in `fn f<T>(x: T)
     /// {}` when we're type-checking the body of that function. In this
     /// situation, we know this stands for *some* type, but don't know the exact
@@ -332,12 +331,6 @@ pub enum Ty {
     /// didn't seem worth the overhead yet.
     Dyn(Arc<[GenericPredicate]>),
 
-    /// An opaque type (`impl Trait`).
-    ///
-    /// The predicates are quantified over the `Self` type; see `Ty::Dyn` for
-    /// more.
-    Opaque(Arc<[GenericPredicate]>),
-
     /// A placeholder for a type which could not be computed; this is propagated
     /// to avoid useless error messages. Doubles as a placeholder where type
     /// variables are inserted before type checking, since we want to try to
@@ -490,7 +483,7 @@ impl Deref for Substs {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 pub struct Binders<T> {
     pub num_binders: usize,
     pub value: T,
@@ -534,6 +527,20 @@ impl<T: TypeWalk> Binders<T> {
     }
 }
 
+impl<T: TypeWalk> TypeWalk for Binders<T> {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        self.value.walk(f);
+    }
+
+    fn walk_mut_binders(
+        &mut self,
+        f: &mut impl FnMut(&mut Ty, DebruijnIndex),
+        binders: DebruijnIndex,
+    ) {
+        self.value.walk_mut_binders(f, binders.shifted_in())
+    }
+}
+
 /// A trait with type parameters. This includes the `Self`, so this represents a concrete type implementing the trait.
 /// Name to be bikeshedded: TraitBound? TraitImplements?
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -578,17 +585,11 @@ pub enum GenericPredicate {
 
 impl GenericPredicate {
     pub fn is_error(&self) -> bool {
-        match self {
-            GenericPredicate::Error => true,
-            _ => false,
-        }
+        matches!(self, GenericPredicate::Error)
     }
 
     pub fn is_implemented(&self) -> bool {
-        match self {
-            GenericPredicate::Implemented(_) => true,
-            _ => false,
-        }
+        matches!(self, GenericPredicate::Implemented(_))
     }
 
     pub fn trait_ref(&self, db: &dyn HirDatabase) -> Option<TraitRef> {
@@ -626,13 +627,27 @@ impl TypeWalk for GenericPredicate {
 
 /// Basically a claim (currently not validated / checked) that the contained
 /// type / trait ref contains no inference variables; any inference variables it
-/// contained have been replaced by bound variables, and `num_vars` tells us how
-/// many there are. This is used to erase irrelevant differences between types
-/// before using them in queries.
+/// contained have been replaced by bound variables, and `kinds` tells us how
+/// many there are and whether they were normal or float/int variables. This is
+/// used to erase irrelevant differences between types before using them in
+/// queries.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Canonical<T> {
     pub value: T,
-    pub num_vars: usize,
+    pub kinds: Arc<[TyKind]>,
+}
+
+impl<T> Canonical<T> {
+    pub fn new(value: T, kinds: impl IntoIterator<Item = TyKind>) -> Self {
+        Self { value, kinds: kinds.into_iter().collect() }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum TyKind {
+    General,
+    Integer,
+    Float,
 }
 
 /// A function signature as seen by type inference: Several parameter types and
@@ -640,19 +655,20 @@ pub struct Canonical<T> {
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct FnSig {
     params_and_return: Arc<[Ty]>,
+    is_varargs: bool,
 }
 
 /// A polymorphic function signature.
 pub type PolyFnSig = Binders<FnSig>;
 
 impl FnSig {
-    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty) -> FnSig {
+    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> FnSig {
         params.push(ret);
-        FnSig { params_and_return: params.into() }
+        FnSig { params_and_return: params.into(), is_varargs }
     }
 
-    pub fn from_fn_ptr_substs(substs: &Substs) -> FnSig {
-        FnSig { params_and_return: Arc::clone(&substs.0) }
+    pub fn from_fn_ptr_substs(substs: &Substs, is_varargs: bool) -> FnSig {
+        FnSig { params_and_return: Arc::clone(&substs.0), is_varargs }
     }
 
     pub fn params(&self) -> &[Ty] {
@@ -697,7 +713,7 @@ impl Ty {
     }
     pub fn fn_ptr(sig: FnSig) -> Self {
         Ty::apply(
-            TypeCtor::FnPtr { num_args: sig.params().len() as u16 },
+            TypeCtor::FnPtr { num_args: sig.params().len() as u16, is_varargs: sig.is_varargs },
             Substs(sig.params_and_return),
         )
     }
@@ -751,7 +767,7 @@ impl Ty {
         }
     }
 
-    pub fn as_callable(&self) -> Option<(CallableDef, &Substs)> {
+    pub fn as_callable(&self) -> Option<(CallableDefId, &Substs)> {
         match self {
             Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(callable_def), parameters }) => {
                 Some((*callable_def, parameters))
@@ -775,6 +791,11 @@ impl Ty {
         }
     }
 
+    /// If this is a `dyn Trait`, returns that trait.
+    pub fn dyn_trait(&self) -> Option<TraitId> {
+        self.dyn_trait_ref().map(|it| it.trait_)
+    }
+
     fn builtin_deref(&self) -> Option<Ty> {
         match self {
             Ty::Apply(a_ty) => match a_ty.ctor {
@@ -789,7 +810,9 @@ impl Ty {
     fn callable_sig(&self, db: &dyn HirDatabase) -> Option<FnSig> {
         match self {
             Ty::Apply(a_ty) => match a_ty.ctor {
-                TypeCtor::FnPtr { .. } => Some(FnSig::from_fn_ptr_substs(&a_ty.parameters)),
+                TypeCtor::FnPtr { is_varargs, .. } => {
+                    Some(FnSig::from_fn_ptr_substs(&a_ty.parameters, is_varargs))
+                }
                 TypeCtor::FnDef(def) => {
                     let sig = db.callable_item_signature(def);
                     Some(sig.subst(&a_ty.parameters))
@@ -827,13 +850,56 @@ impl Ty {
         }
     }
 
-    /// If this is a `dyn Trait`, returns that trait.
-    pub fn dyn_trait(&self) -> Option<TraitId> {
+    pub fn impl_trait_bounds(&self, db: &dyn HirDatabase) -> Option<Vec<GenericPredicate>> {
         match self {
-            Ty::Dyn(predicates) => predicates.iter().find_map(|pred| match pred {
-                GenericPredicate::Implemented(tr) => Some(tr.trait_),
-                _ => None,
-            }),
+            Ty::Opaque(opaque_ty) => {
+                let predicates = match opaque_ty.opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                        db.return_type_impl_traits(func).map(|it| {
+                            let data = (*it)
+                                .as_ref()
+                                .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                            data.subst(&opaque_ty.parameters)
+                        })
+                    }
+                };
+
+                predicates.map(|it| it.value)
+            }
+            Ty::Placeholder(id) => {
+                let generic_params = db.generic_params(id.parent);
+                let param_data = &generic_params.types[id.local_id];
+                match param_data.provenance {
+                    hir_def::generics::TypeParamProvenance::ArgumentImplTrait => {
+                        let predicates = db
+                            .generic_predicates_for_param(*id)
+                            .into_iter()
+                            .map(|pred| pred.value.clone())
+                            .collect_vec();
+
+                        Some(predicates)
+                    }
+                    _ => None,
+                }
+            }
+            _ => None,
+        }
+    }
+
+    pub fn associated_type_parent_trait(&self, db: &dyn HirDatabase) -> Option<TraitId> {
+        match self {
+            Ty::Apply(ApplicationTy { ctor: TypeCtor::AssociatedType(type_alias_id), .. }) => {
+                match type_alias_id.lookup(db.upcast()).container {
+                    AssocContainerId::TraitId(trait_id) => Some(trait_id),
+                    _ => None,
+                }
+            }
+            Ty::Projection(projection_ty) => {
+                match projection_ty.associated_ty.lookup(db.upcast()).container {
+                    AssocContainerId::TraitId(trait_id) => Some(trait_id),
+                    _ => None,
+                }
+            }
             _ => None,
         }
     }
@@ -947,11 +1013,16 @@ impl TypeWalk for Ty {
                     t.walk(f);
                 }
             }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+            Ty::Dyn(predicates) => {
                 for p in predicates.iter() {
                     p.walk(f);
                 }
             }
+            Ty::Opaque(o_ty) => {
+                for t in o_ty.parameters.iter() {
+                    t.walk(f);
+                }
+            }
             Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self);
@@ -969,13 +1040,48 @@ impl TypeWalk for Ty {
             Ty::Projection(p_ty) => {
                 p_ty.parameters.walk_mut_binders(f, binders);
             }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+            Ty::Dyn(predicates) => {
                 for p in make_mut_slice(predicates) {
                     p.walk_mut_binders(f, binders.shifted_in());
                 }
             }
+            Ty::Opaque(o_ty) => {
+                o_ty.parameters.walk_mut_binders(f, binders);
+            }
             Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self, binders);
     }
 }
+
+impl<T: TypeWalk> TypeWalk for Vec<T> {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        for t in self {
+            t.walk(f);
+        }
+    }
+    fn walk_mut_binders(
+        &mut self,
+        f: &mut impl FnMut(&mut Ty, DebruijnIndex),
+        binders: DebruijnIndex,
+    ) {
+        for t in self {
+            t.walk_mut_binders(f, binders);
+        }
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
+pub enum OpaqueTyId {
+    ReturnTypeImplTrait(hir_def::FunctionId, u16),
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct ReturnTypeImplTraits {
+    pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub(crate) struct ReturnTypeImplTrait {
+    pub bounds: Binders<Vec<GenericPredicate>>,
+}
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 35ac86a46..f274579ea 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -5,10 +5,7 @@
 //!  - Building the type for an item: This happens through the `type_for_def` query.
 //!
 //! This usually involves resolving names, collecting generic arguments etc.
-use std::iter;
-use std::sync::Arc;
-
-use smallvec::SmallVec;
+use std::{iter, sync::Arc};
 
 use hir_def::{
     adt::StructKind,
@@ -21,8 +18,12 @@ use hir_def::{
     HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
     UnionId, VariantId,
 };
+use hir_expand::name::Name;
 use ra_arena::map::ArenaMap;
 use ra_db::CrateId;
+use smallvec::SmallVec;
+use stdx::impl_from;
+use test_utils::mark;
 
 use crate::{
     db::HirDatabase,
@@ -31,10 +32,10 @@ use crate::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
         make_mut_slice, variant_data,
     },
-    Binders, BoundVar, DebruijnIndex, FnSig, GenericPredicate, PolyFnSig, ProjectionPredicate,
-    ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
+    Binders, BoundVar, DebruijnIndex, FnSig, GenericPredicate, OpaqueTy, OpaqueTyId, PolyFnSig,
+    ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait, ReturnTypeImplTraits, Substs,
+    TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
-use hir_expand::name::Name;
 
 #[derive(Debug)]
 pub struct TyLoweringContext<'a> {
@@ -47,7 +48,16 @@ pub struct TyLoweringContext<'a> {
     /// possible currently, so this should be fine for now.
     pub type_param_mode: TypeParamLoweringMode,
     pub impl_trait_mode: ImplTraitLoweringMode,
-    pub impl_trait_counter: std::cell::Cell<u16>,
+    impl_trait_counter: std::cell::Cell<u16>,
+    /// When turning `impl Trait` into opaque types, we have to collect the
+    /// bounds at the same time to get the IDs correct (without becoming too
+    /// complicated). I don't like using interior mutability (as for the
+    /// counter), but I've tried and failed to make the lifetimes work for
+    /// passing around a `&mut TyLoweringContext`. The core problem is that
+    /// we're grouping the mutable data (the counter and this field) together
+    /// with the immutable context (the references to the DB and resolver).
+    /// Splitting this up would be a possible fix.
+    opaque_type_data: std::cell::RefCell<Vec<ReturnTypeImplTrait>>,
 }
 
 impl<'a> TyLoweringContext<'a> {
@@ -56,26 +66,42 @@ impl<'a> TyLoweringContext<'a> {
         let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
         let type_param_mode = TypeParamLoweringMode::Placeholder;
         let in_binders = DebruijnIndex::INNERMOST;
-        Self { db, resolver, in_binders, impl_trait_mode, impl_trait_counter, type_param_mode }
+        let opaque_type_data = std::cell::RefCell::new(Vec::new());
+        Self {
+            db,
+            resolver,
+            in_binders,
+            impl_trait_mode,
+            impl_trait_counter,
+            type_param_mode,
+            opaque_type_data,
+        }
     }
 
-    pub fn with_shifted_in<T>(
+    pub fn with_debruijn<T>(
         &self,
         debruijn: DebruijnIndex,
         f: impl FnOnce(&TyLoweringContext) -> T,
     ) -> T {
+        let opaque_ty_data_vec = self.opaque_type_data.replace(Vec::new());
         let new_ctx = Self {
-            in_binders: self.in_binders.shifted_in_from(debruijn),
+            in_binders: debruijn,
             impl_trait_counter: std::cell::Cell::new(self.impl_trait_counter.get()),
+            opaque_type_data: std::cell::RefCell::new(opaque_ty_data_vec),
             ..*self
         };
         let result = f(&new_ctx);
         self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
+        self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
         result
     }
 
-    pub fn shifted_in(self, debruijn: DebruijnIndex) -> Self {
-        Self { in_binders: self.in_binders.shifted_in_from(debruijn), ..self }
+    pub fn with_shifted_in<T>(
+        &self,
+        debruijn: DebruijnIndex,
+        f: impl FnOnce(&TyLoweringContext) -> T,
+    ) -> T {
+        self.with_debruijn(self.in_binders.shifted_in_from(debruijn), f)
     }
 
     pub fn with_impl_trait_mode(self, impl_trait_mode: ImplTraitLoweringMode) -> Self {
@@ -150,9 +176,12 @@ impl Ty {
                 Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
             }
             TypeRef::Placeholder => Ty::Unknown,
-            TypeRef::Fn(params) => {
+            TypeRef::Fn(params, is_varargs) => {
                 let sig = Substs(params.iter().map(|tr| Ty::from_hir(ctx, tr)).collect());
-                Ty::apply(TypeCtor::FnPtr { num_args: sig.len() as u16 - 1 }, sig)
+                Ty::apply(
+                    TypeCtor::FnPtr { num_args: sig.len() as u16 - 1, is_varargs: *is_varargs },
+                    sig,
+                )
             }
             TypeRef::DynTrait(bounds) => {
                 let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
@@ -167,20 +196,44 @@ impl Ty {
             TypeRef::ImplTrait(bounds) => {
                 match ctx.impl_trait_mode {
                     ImplTraitLoweringMode::Opaque => {
-                        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
-                        let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
-                            bounds
-                                .iter()
-                                .flat_map(|b| {
-                                    GenericPredicate::from_type_bound(ctx, b, self_ty.clone())
-                                })
-                                .collect()
-                        });
-                        Ty::Opaque(predicates)
+                        let idx = ctx.impl_trait_counter.get();
+                        ctx.impl_trait_counter.set(idx + 1);
+
+                        assert!(idx as usize == ctx.opaque_type_data.borrow().len());
+                        // this dance is to make sure the data is in the right
+                        // place even if we encounter more opaque types while
+                        // lowering the bounds
+                        ctx.opaque_type_data
+                            .borrow_mut()
+                            .push(ReturnTypeImplTrait { bounds: Binders::new(1, Vec::new()) });
+                        // We don't want to lower the bounds inside the binders
+                        // we're currently in, because they don't end up inside
+                        // those binders. E.g. when we have `impl Trait<impl
+                        // OtherTrait<T>>`, the `impl OtherTrait<T>` can't refer
+                        // to the self parameter from `impl Trait`, and the
+                        // bounds aren't actually stored nested within each
+                        // other, but separately. So if the `T` refers to a type
+                        // parameter of the outer function, it's just one binder
+                        // away instead of two.
+                        let actual_opaque_type_data = ctx
+                            .with_debruijn(DebruijnIndex::INNERMOST, |ctx| {
+                                ReturnTypeImplTrait::from_hir(ctx, &bounds)
+                            });
+                        ctx.opaque_type_data.borrow_mut()[idx as usize] = actual_opaque_type_data;
+
+                        let func = match ctx.resolver.generic_def() {
+                            Some(GenericDefId::FunctionId(f)) => f,
+                            _ => panic!("opaque impl trait lowering in non-function"),
+                        };
+                        let impl_trait_id = OpaqueTyId::ReturnTypeImplTrait(func, idx);
+                        let generics = generics(ctx.db.upcast(), func.into());
+                        let parameters = Substs::bound_vars(&generics, ctx.in_binders);
+                        Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
                     }
                     ImplTraitLoweringMode::Param => {
                         let idx = ctx.impl_trait_counter.get();
-                        ctx.impl_trait_counter.set(idx + 1);
+                        // FIXME we're probably doing something wrong here
+                        ctx.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
                         if let Some(def) = ctx.resolver.generic_def() {
                             let generics = generics(ctx.db.upcast(), def);
                             let param = generics
@@ -197,7 +250,8 @@ impl Ty {
                     }
                     ImplTraitLoweringMode::Variable => {
                         let idx = ctx.impl_trait_counter.get();
-                        ctx.impl_trait_counter.set(idx + 1);
+                        // FIXME we're probably doing something wrong here
+                        ctx.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
                         let (parent_params, self_params, list_params, _impl_trait_params) =
                             if let Some(def) = ctx.resolver.generic_def() {
                                 let generics = generics(ctx.db.upcast(), def);
@@ -271,6 +325,7 @@ impl Ty {
         resolution: TypeNs,
         resolved_segment: PathSegment<'_>,
         remaining_segments: PathSegments<'_>,
+        infer_args: bool,
     ) -> (Ty, Option<TypeNs>) {
         let ty = match resolution {
             TypeNs::TraitId(trait_) => {
@@ -284,17 +339,17 @@ impl Ty {
                     TraitRef::from_resolved_path(ctx, trait_, resolved_segment, self_ty);
                 let ty = if remaining_segments.len() == 1 {
                     let segment = remaining_segments.first().unwrap();
-                    let associated_ty = associated_type_by_name_including_super_traits(
-                        ctx.db.upcast(),
-                        trait_ref.trait_,
+                    let found = associated_type_by_name_including_super_traits(
+                        ctx.db,
+                        trait_ref.clone(),
                         &segment.name,
                     );
-                    match associated_ty {
-                        Some(associated_ty) => {
+                    match found {
+                        Some((super_trait_ref, associated_ty)) => {
                             // FIXME handle type parameters on the segment
                             Ty::Projection(ProjectionTy {
                                 associated_ty,
-                                parameters: trait_ref.substs,
+                                parameters: super_trait_ref.substs,
                             })
                         }
                         None => {
@@ -348,9 +403,15 @@ impl Ty {
                 ctx.db.ty(adt.into()).subst(&substs)
             }
 
-            TypeNs::AdtId(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
-            TypeNs::BuiltinType(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
-            TypeNs::TypeAliasId(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
+            TypeNs::AdtId(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
+            TypeNs::BuiltinType(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
+            TypeNs::TypeAliasId(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
             // FIXME: report error
             TypeNs::EnumVariantId(_) => return (Ty::Unknown, None),
         };
@@ -376,7 +437,13 @@ impl Ty {
             ),
             Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
         };
-        Ty::from_partly_resolved_hir_path(ctx, resolution, resolved_segment, remaining_segments)
+        Ty::from_partly_resolved_hir_path(
+            ctx,
+            resolution,
+            resolved_segment,
+            remaining_segments,
+            false,
+        )
     }
 
     fn select_associated_type(
@@ -402,6 +469,9 @@ impl Ty {
                             }
                             TypeParamLoweringMode::Variable => t.substs.clone(),
                         };
+                        // We need to shift in the bound vars, since
+                        // associated_type_shorthand_candidates does not do that
+                        let substs = substs.shift_bound_vars(ctx.in_binders);
                         // FIXME handle type parameters on the segment
                         return Some(Ty::Projection(ProjectionTy {
                             associated_ty,
@@ -422,13 +492,14 @@ impl Ty {
         ctx: &TyLoweringContext<'_>,
         segment: PathSegment<'_>,
         typable: TyDefId,
+        infer_args: bool,
     ) -> Ty {
         let generic_def = match typable {
             TyDefId::BuiltinType(_) => None,
             TyDefId::AdtId(it) => Some(it.into()),
             TyDefId::TypeAliasId(it) => Some(it.into()),
         };
-        let substs = substs_from_path_segment(ctx, segment, generic_def, false);
+        let substs = substs_from_path_segment(ctx, segment, generic_def, infer_args);
         ctx.db.ty(typable).subst(&substs)
     }
 
@@ -441,6 +512,7 @@ impl Ty {
         // `ValueTyDefId` is just a convenient way to pass generics and
         // special-case enum variants
         resolved: ValueTyDefId,
+        infer_args: bool,
     ) -> Substs {
         let last = path.segments().last().expect("path should have at least one segment");
         let (segment, generic_def) = match resolved {
@@ -463,22 +535,27 @@ impl Ty {
                 (segment, Some(var.parent.into()))
             }
         };
-        substs_from_path_segment(ctx, segment, generic_def, false)
+        substs_from_path_segment(ctx, segment, generic_def, infer_args)
     }
 }
 
-pub(super) fn substs_from_path_segment(
+fn substs_from_path_segment(
     ctx: &TyLoweringContext<'_>,
     segment: PathSegment<'_>,
     def_generic: Option<GenericDefId>,
-    _add_self_param: bool,
+    infer_args: bool,
 ) -> Substs {
     let mut substs = Vec::new();
     let def_generics = def_generic.map(|def| generics(ctx.db.upcast(), def));
 
     let (parent_params, self_params, type_params, impl_trait_params) =
         def_generics.map_or((0, 0, 0, 0), |g| g.provenance_split());
+    let total_len = parent_params + self_params + type_params + impl_trait_params;
+
     substs.extend(iter::repeat(Ty::Unknown).take(parent_params));
+
+    let mut had_explicit_args = false;
+
     if let Some(generic_args) = &segment.args_and_bindings {
         if !generic_args.has_self_type {
             substs.extend(iter::repeat(Ty::Unknown).take(self_params));
@@ -490,31 +567,37 @@ pub(super) fn substs_from_path_segment(
         for arg in generic_args.args.iter().skip(skip).take(expected_num) {
             match arg {
                 GenericArg::Type(type_ref) => {
+                    had_explicit_args = true;
                     let ty = Ty::from_hir(ctx, type_ref);
                     substs.push(ty);
                 }
             }
         }
     }
-    let total_len = parent_params + self_params + type_params + impl_trait_params;
+
+    // handle defaults. In expression or pattern path segments without
+    // explicitly specified type arguments, missing type arguments are inferred
+    // (i.e. defaults aren't used).
+    if !infer_args || had_explicit_args {
+        if let Some(def_generic) = def_generic {
+            let defaults = ctx.db.generic_defaults(def_generic);
+            assert_eq!(total_len, defaults.len());
+
+            for default_ty in defaults.iter().skip(substs.len()) {
+                // each default can depend on the previous parameters
+                let substs_so_far = Substs(substs.clone().into());
+                substs.push(default_ty.clone().subst(&substs_so_far));
+            }
+        }
+    }
+
     // add placeholders for args that were not provided
+    // FIXME: emit diagnostics in contexts where this is not allowed
     for _ in substs.len()..total_len {
         substs.push(Ty::Unknown);
     }
     assert_eq!(substs.len(), total_len);
 
-    // handle defaults
-    if let Some(def_generic) = def_generic {
-        let default_substs = ctx.db.generic_defaults(def_generic);
-        assert_eq!(substs.len(), default_substs.len());
-
-        for (i, default_ty) in default_substs.iter().enumerate() {
-            if substs[i] == Ty::Unknown {
-                substs[i] = default_ty.clone();
-            }
-        }
-    }
-
     Substs(substs.into())
 }
 
@@ -563,9 +646,7 @@ impl TraitRef {
         segment: PathSegment<'_>,
         resolved: TraitId,
     ) -> Substs {
-        let has_self_param =
-            segment.args_and_bindings.as_ref().map(|a| a.has_self_type).unwrap_or(false);
-        substs_from_path_segment(ctx, segment, Some(resolved.into()), !has_self_param)
+        substs_from_path_segment(ctx, segment, Some(resolved.into()), false)
     }
 
     pub(crate) fn from_type_bound(
@@ -632,17 +713,16 @@ fn assoc_type_bindings_from_type_bound<'a>(
         .flat_map(|segment| segment.args_and_bindings.into_iter())
         .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
         .flat_map(move |binding| {
-            let associated_ty = associated_type_by_name_including_super_traits(
-                ctx.db.upcast(),
-                trait_ref.trait_,
+            let found = associated_type_by_name_including_super_traits(
+                ctx.db,
+                trait_ref.clone(),
                 &binding.name,
             );
-            let associated_ty = match associated_ty {
+            let (super_trait_ref, associated_ty) = match found {
                 None => return SmallVec::<[GenericPredicate; 1]>::new(),
                 Some(t) => t,
             };
-            let projection_ty =
-                ProjectionTy { associated_ty, parameters: trait_ref.substs.clone() };
+            let projection_ty = ProjectionTy { associated_ty, parameters: super_trait_ref.substs };
             let mut preds = SmallVec::with_capacity(
                 binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(),
             );
@@ -663,12 +743,36 @@ fn assoc_type_bindings_from_type_bound<'a>(
         })
 }
 
+impl ReturnTypeImplTrait {
+    fn from_hir(ctx: &TyLoweringContext, bounds: &[TypeBound]) -> Self {
+        mark::hit!(lower_rpit);
+        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+        let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
+            bounds
+                .iter()
+                .flat_map(|b| GenericPredicate::from_type_bound(ctx, b, self_ty.clone()))
+                .collect()
+        });
+        ReturnTypeImplTrait { bounds: Binders::new(1, predicates) }
+    }
+}
+
+fn count_impl_traits(type_ref: &TypeRef) -> usize {
+    let mut count = 0;
+    type_ref.walk(&mut |type_ref| {
+        if matches!(type_ref, TypeRef::ImplTrait(_)) {
+            count += 1;
+        }
+    });
+    count
+}
+
 /// Build the signature of a callable item (function, struct or enum variant).
-pub fn callable_item_sig(db: &dyn HirDatabase, def: CallableDef) -> PolyFnSig {
+pub fn callable_item_sig(db: &dyn HirDatabase, def: CallableDefId) -> PolyFnSig {
     match def {
-        CallableDef::FunctionId(f) => fn_sig_for_fn(db, f),
-        CallableDef::StructId(s) => fn_sig_for_struct_constructor(db, s),
-        CallableDef::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
+        CallableDefId::FunctionId(f) => fn_sig_for_fn(db, f),
+        CallableDefId::StructId(s) => fn_sig_for_struct_constructor(db, s),
+        CallableDefId::EnumVariantId(e) => fn_sig_for_enum_variant_constructor(db, e),
     }
 }
 
@@ -844,17 +948,42 @@ pub(crate) fn generic_predicates_query(
 }
 
 /// Resolve the default type params from generics
-pub(crate) fn generic_defaults_query(db: &dyn HirDatabase, def: GenericDefId) -> Substs {
+pub(crate) fn generic_defaults_query(
+    db: &dyn HirDatabase,
+    def: GenericDefId,
+) -> Arc<[Binders<Ty>]> {
     let resolver = def.resolver(db.upcast());
-    let ctx = TyLoweringContext::new(db, &resolver);
+    let ctx =
+        TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
     let generic_params = generics(db.upcast(), def);
 
     let defaults = generic_params
         .iter()
-        .map(|(_idx, p)| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(&ctx, t)))
+        .enumerate()
+        .map(|(idx, (_, p))| {
+            let mut ty = p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(&ctx, t));
+
+            // Each default can only refer to previous parameters.
+            ty.walk_mut_binders(
+                &mut |ty, binders| match ty {
+                    Ty::Bound(BoundVar { debruijn, index }) if *debruijn == binders => {
+                        if *index >= idx {
+                            // type variable default referring to parameter coming
+                            // after it. This is forbidden (FIXME: report
+                            // diagnostic)
+                            *ty = Ty::Unknown;
+                        }
+                    }
+                    _ => {}
+                },
+                DebruijnIndex::INNERMOST,
+            );
+
+            Binders::new(idx, ty)
+        })
         .collect();
 
-    Substs(defaults)
+    defaults
 }
 
 fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
@@ -864,11 +993,13 @@ fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
         .with_impl_trait_mode(ImplTraitLoweringMode::Variable)
         .with_type_param_mode(TypeParamLoweringMode::Variable);
     let params = data.params.iter().map(|tr| Ty::from_hir(&ctx_params, tr)).collect::<Vec<_>>();
-    let ctx_ret = ctx_params.with_impl_trait_mode(ImplTraitLoweringMode::Opaque);
+    let ctx_ret = TyLoweringContext::new(db, &resolver)
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
+        .with_type_param_mode(TypeParamLoweringMode::Variable);
     let ret = Ty::from_hir(&ctx_ret, &data.ret_type);
     let generics = generics(db.upcast(), def.into());
     let num_binders = generics.len();
-    Binders::new(num_binders, FnSig::from_params_and_return(params, ret))
+    Binders::new(num_binders, FnSig::from_params_and_return(params, ret, data.is_varargs))
 }
 
 /// Build the declared type of a function. This should not need to look at the
@@ -919,7 +1050,7 @@ fn fn_sig_for_struct_constructor(db: &dyn HirDatabase, def: StructId) -> PolyFnS
     let params =
         fields.iter().map(|(_, field)| Ty::from_hir(&ctx, &field.type_ref)).collect::<Vec<_>>();
     let ret = type_for_adt(db, def.into());
-    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value))
+    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value, false))
 }
 
 /// Build the type of a tuple struct constructor.
@@ -943,7 +1074,7 @@ fn fn_sig_for_enum_variant_constructor(db: &dyn HirDatabase, def: EnumVariantId)
     let params =
         fields.iter().map(|(_, field)| Ty::from_hir(&ctx, &field.type_ref)).collect::<Vec<_>>();
     let ret = type_for_adt(db, def.parent.into());
-    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value))
+    Binders::new(ret.num_binders, FnSig::from_params_and_return(params, ret.value, false))
 }
 
 /// Build the type of a tuple enum variant constructor.
@@ -976,31 +1107,31 @@ fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum CallableDef {
+pub enum CallableDefId {
     FunctionId(FunctionId),
     StructId(StructId),
     EnumVariantId(EnumVariantId),
 }
-impl_froms!(CallableDef: FunctionId, StructId, EnumVariantId);
+impl_from!(FunctionId, StructId, EnumVariantId for CallableDefId);
 
-impl CallableDef {
+impl CallableDefId {
     pub fn krate(self, db: &dyn HirDatabase) -> CrateId {
         let db = db.upcast();
         match self {
-            CallableDef::FunctionId(f) => f.lookup(db).module(db),
-            CallableDef::StructId(s) => s.lookup(db).container.module(db),
-            CallableDef::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
+            CallableDefId::FunctionId(f) => f.lookup(db).module(db),
+            CallableDefId::StructId(s) => s.lookup(db).container.module(db),
+            CallableDefId::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
         }
         .krate
     }
 }
 
-impl From<CallableDef> for GenericDefId {
-    fn from(def: CallableDef) -> GenericDefId {
+impl From<CallableDefId> for GenericDefId {
+    fn from(def: CallableDefId) -> GenericDefId {
         match def {
-            CallableDef::FunctionId(f) => f.into(),
-            CallableDef::StructId(s) => s.into(),
-            CallableDef::EnumVariantId(e) => e.into(),
+            CallableDefId::FunctionId(f) => f.into(),
+            CallableDefId::StructId(s) => s.into(),
+            CallableDefId::EnumVariantId(e) => e.into(),
         }
     }
 }
@@ -1011,7 +1142,7 @@ pub enum TyDefId {
     AdtId(AdtId),
     TypeAliasId(TypeAliasId),
 }
-impl_froms!(TyDefId: BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId);
+impl_from!(BuiltinType, AdtId(StructId, EnumId, UnionId), TypeAliasId for TyDefId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum ValueTyDefId {
@@ -1021,7 +1152,7 @@ pub enum ValueTyDefId {
     ConstId(ConstId),
     StaticId(StaticId),
 }
-impl_froms!(ValueTyDefId: FunctionId, StructId, EnumVariantId, ConstId, StaticId);
+impl_from!(FunctionId, StructId, EnumVariantId, ConstId, StaticId for ValueTyDefId);
 
 /// Build the declared type of an item. This depends on the namespace; e.g. for
 /// `struct Foo(usize)`, we have two types: The type of the struct itself, and
@@ -1084,3 +1215,25 @@ pub(crate) fn impl_trait_query(db: &dyn HirDatabase, impl_id: ImplId) -> Option<
         TraitRef::from_hir(&ctx, target_trait, Some(self_ty.value))?,
     ))
 }
+
+pub(crate) fn return_type_impl_traits(
+    db: &dyn HirDatabase,
+    def: hir_def::FunctionId,
+) -> Option<Arc<Binders<ReturnTypeImplTraits>>> {
+    // FIXME unify with fn_sig_for_fn instead of doing lowering twice, maybe
+    let data = db.function_data(def);
+    let resolver = def.resolver(db.upcast());
+    let ctx_ret = TyLoweringContext::new(db, &resolver)
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
+        .with_type_param_mode(TypeParamLoweringMode::Variable);
+    let _ret = Ty::from_hir(&ctx_ret, &data.ret_type);
+    let generics = generics(db.upcast(), def.into());
+    let num_binders = generics.len();
+    let return_type_impl_traits =
+        ReturnTypeImplTraits { impl_traits: ctx_ret.opaque_type_data.into_inner() };
+    if return_type_impl_traits.impl_traits.is_empty() {
+        None
+    } else {
+        Some(Arc::new(Binders::new(num_binders, return_type_impl_traits)))
+    }
+}
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index e19628fdf..fb4b30a13 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -2,12 +2,14 @@
 //! For details about how this works in rustc, see the method lookup page in the
 //! [rustc guide](https://rust-lang.github.io/rustc-guide/method-lookup.html)
 //! and the corresponding code mostly in librustc_typeck/check/method/probe.rs.
-use std::sync::Arc;
+use std::{iter, sync::Arc};
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, type_ref::Mutability, AssocContainerId, AssocItemId, FunctionId,
-    HasModule, ImplId, Lookup, TraitId,
+    builtin_type::{IntBitness, Signedness},
+    lang_item::LangItemTarget,
+    type_ref::Mutability,
+    AssocContainerId, AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
@@ -18,9 +20,9 @@ use super::Substs;
 use crate::{
     autoderef,
     db::HirDatabase,
-    primitive::{FloatBitness, Uncertain},
+    primitive::{FloatBitness, FloatTy, IntTy},
     utils::all_super_traits,
-    ApplicationTy, Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty,
+    ApplicationTy, Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TyKind,
     TypeCtor, TypeWalk,
 };
 
@@ -42,83 +44,187 @@ impl TyFingerprint {
     }
 }
 
-#[derive(Debug, PartialEq, Eq)]
-pub struct CrateImplDefs {
-    impls: FxHashMap<TyFingerprint, Vec<ImplId>>,
-    impls_by_trait: FxHashMap<TraitId, FxHashMap<Option<TyFingerprint>, Vec<ImplId>>>,
+pub(crate) const ALL_INT_FPS: [TyFingerprint; 12] = [
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X8,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X16,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X32,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X64,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::X128,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Unsigned,
+        bitness: IntBitness::Xsize,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X8,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X16,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X32,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X64,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::X128,
+    })),
+    TyFingerprint::Apply(TypeCtor::Int(IntTy {
+        signedness: Signedness::Signed,
+        bitness: IntBitness::Xsize,
+    })),
+];
+
+pub(crate) const ALL_FLOAT_FPS: [TyFingerprint; 2] = [
+    TyFingerprint::Apply(TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 })),
+    TyFingerprint::Apply(TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 })),
+];
+
+/// Trait impls defined or available in some crate.
+#[derive(Debug, Eq, PartialEq)]
+pub struct TraitImpls {
+    // If the `Option<TyFingerprint>` is `None`, the impl may apply to any self type.
+    map: FxHashMap<TraitId, FxHashMap<Option<TyFingerprint>, Vec<ImplId>>>,
 }
 
-impl CrateImplDefs {
-    pub(crate) fn impls_in_crate_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<CrateImplDefs> {
-        let _p = profile("impls_in_crate_query");
-        let mut res =
-            CrateImplDefs { impls: FxHashMap::default(), impls_by_trait: FxHashMap::default() };
+impl TraitImpls {
+    pub(crate) fn trait_impls_in_crate_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<Self> {
+        let _p = profile("trait_impls_in_crate_query");
+        let mut impls = Self { map: FxHashMap::default() };
 
         let crate_def_map = db.crate_def_map(krate);
         for (_module_id, module_data) in crate_def_map.modules.iter() {
             for impl_id in module_data.scope.impls() {
-                match db.impl_trait(impl_id) {
-                    Some(tr) => {
-                        let self_ty = db.impl_self_ty(impl_id);
-                        let self_ty_fp = TyFingerprint::for_impl(&self_ty.value);
-                        res.impls_by_trait
-                            .entry(tr.value.trait_)
-                            .or_default()
-                            .entry(self_ty_fp)
-                            .or_default()
-                            .push(impl_id);
-                    }
-                    None => {
-                        let self_ty = db.impl_self_ty(impl_id);
-                        if let Some(self_ty_fp) = TyFingerprint::for_impl(&self_ty.value) {
-                            res.impls.entry(self_ty_fp).or_default().push(impl_id);
-                        }
-                    }
-                }
+                let target_trait = match db.impl_trait(impl_id) {
+                    Some(tr) => tr.value.trait_,
+                    None => continue,
+                };
+                let self_ty = db.impl_self_ty(impl_id);
+                let self_ty_fp = TyFingerprint::for_impl(&self_ty.value);
+                impls
+                    .map
+                    .entry(target_trait)
+                    .or_default()
+                    .entry(self_ty_fp)
+                    .or_default()
+                    .push(impl_id);
             }
         }
 
+        Arc::new(impls)
+    }
+
+    pub(crate) fn trait_impls_in_deps_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<Self> {
+        let _p = profile("trait_impls_in_deps_query");
+        let crate_graph = db.crate_graph();
+        let mut res = Self { map: FxHashMap::default() };
+
+        for krate in crate_graph.transitive_deps(krate) {
+            res.merge(&db.trait_impls_in_crate(krate));
+        }
+
         Arc::new(res)
     }
-    pub fn lookup_impl_defs(&self, ty: &Ty) -> impl Iterator<Item = ImplId> + '_ {
-        let fingerprint = TyFingerprint::for_impl(ty);
-        fingerprint.and_then(|f| self.impls.get(&f)).into_iter().flatten().copied()
+
+    fn merge(&mut self, other: &Self) {
+        for (trait_, other_map) in &other.map {
+            let map = self.map.entry(*trait_).or_default();
+            for (fp, impls) in other_map {
+                let vec = map.entry(*fp).or_default();
+                vec.extend(impls);
+            }
+        }
     }
 
-    pub fn lookup_impl_defs_for_trait(&self, tr: TraitId) -> impl Iterator<Item = ImplId> + '_ {
-        self.impls_by_trait
-            .get(&tr)
+    /// Queries all impls of the given trait.
+    pub fn for_trait(&self, trait_: TraitId) -> impl Iterator<Item = ImplId> + '_ {
+        self.map
+            .get(&trait_)
             .into_iter()
-            .flat_map(|m| m.values().flat_map(|v| v.iter().copied()))
+            .flat_map(|map| map.values().flat_map(|v| v.iter().copied()))
     }
 
-    pub fn lookup_impl_defs_for_trait_and_ty(
+    /// Queries all impls of `trait_` that may apply to `self_ty`.
+    pub fn for_trait_and_self_ty(
         &self,
-        tr: TraitId,
-        fp: TyFingerprint,
+        trait_: TraitId,
+        self_ty: TyFingerprint,
     ) -> impl Iterator<Item = ImplId> + '_ {
-        self.impls_by_trait
-            .get(&tr)
-            .and_then(|m| m.get(&Some(fp)))
+        self.map
+            .get(&trait_)
             .into_iter()
-            .flatten()
-            .copied()
-            .chain(
-                self.impls_by_trait
-                    .get(&tr)
-                    .and_then(|m| m.get(&None))
-                    .into_iter()
-                    .flatten()
-                    .copied(),
-            )
+            .flat_map(move |map| map.get(&None).into_iter().chain(map.get(&Some(self_ty))))
+            .flat_map(|v| v.iter().copied())
     }
 
-    pub fn all_impls<'a>(&'a self) -> impl Iterator<Item = ImplId> + 'a {
-        self.impls
-            .values()
-            .chain(self.impls_by_trait.values().flat_map(|m| m.values()))
-            .flatten()
-            .copied()
+    pub fn all_impls(&self) -> impl Iterator<Item = ImplId> + '_ {
+        self.map.values().flat_map(|map| map.values().flat_map(|v| v.iter().copied()))
+    }
+}
+
+/// Inherent impls defined in some crate.
+///
+/// Inherent impls can only be defined in the crate that also defines the self type of the impl
+/// (note that some primitives are considered to be defined by both libcore and liballoc).
+///
+/// This makes inherent impl lookup easier than trait impl lookup since we only have to consider a
+/// single crate.
+#[derive(Debug, Eq, PartialEq)]
+pub struct InherentImpls {
+    map: FxHashMap<TyFingerprint, Vec<ImplId>>,
+}
+
+impl InherentImpls {
+    pub(crate) fn inherent_impls_in_crate_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<Self> {
+        let mut map: FxHashMap<_, Vec<_>> = FxHashMap::default();
+
+        let crate_def_map = db.crate_def_map(krate);
+        for (_module_id, module_data) in crate_def_map.modules.iter() {
+            for impl_id in module_data.scope.impls() {
+                let data = db.impl_data(impl_id);
+                if data.target_trait.is_some() {
+                    continue;
+                }
+
+                let self_ty = db.impl_self_ty(impl_id);
+                if let Some(fp) = TyFingerprint::for_impl(&self_ty.value) {
+                    map.entry(fp).or_default().push(impl_id);
+                }
+            }
+        }
+
+        Arc::new(Self { map })
+    }
+
+    pub fn for_self_ty(&self, self_ty: &Ty) -> &[ImplId] {
+        match TyFingerprint::for_impl(self_ty) {
+            Some(fp) => self.map.get(&fp).map(|vec| vec.as_ref()).unwrap_or(&[]),
+            None => &[],
+        }
+    }
+
+    pub fn all_impls(&self) -> impl Iterator<Item = ImplId> + '_ {
+        self.map.values().flat_map(|v| v.iter().copied())
     }
 }
 
@@ -147,12 +253,12 @@ impl Ty {
                 }
                 TypeCtor::Bool => lang_item_crate!("bool"),
                 TypeCtor::Char => lang_item_crate!("char"),
-                TypeCtor::Float(Uncertain::Known(f)) => match f.bitness {
+                TypeCtor::Float(f) => match f.bitness {
                     // There are two lang items: one in libcore (fXX) and one in libstd (fXX_runtime)
                     FloatBitness::X32 => lang_item_crate!("f32", "f32_runtime"),
                     FloatBitness::X64 => lang_item_crate!("f64", "f64_runtime"),
                 },
-                TypeCtor::Int(Uncertain::Known(i)) => lang_item_crate!(i.ty_to_string()),
+                TypeCtor::Int(i) => lang_item_crate!(i.ty_to_string()),
                 TypeCtor::Str => lang_item_crate!("str_alloc", "str"),
                 TypeCtor::Slice => lang_item_crate!("slice_alloc", "slice"),
                 TypeCtor::RawPtr(Mutability::Shared) => lang_item_crate!("const_ptr"),
@@ -222,6 +328,34 @@ pub fn iterate_method_candidates<T>(
     mode: LookupMode,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
+    let mut slot = None;
+    iterate_method_candidates_impl(
+        ty,
+        db,
+        env,
+        krate,
+        traits_in_scope,
+        name,
+        mode,
+        &mut |ty, item| {
+            assert!(slot.is_none());
+            slot = callback(ty, item);
+            slot.is_some()
+        },
+    );
+    slot
+}
+
+fn iterate_method_candidates_impl(
+    ty: &Canonical<Ty>,
+    db: &dyn HirDatabase,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    traits_in_scope: &FxHashSet<TraitId>,
+    name: Option<&Name>,
+    mode: LookupMode,
+    callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
     match mode {
         LookupMode::MethodCall => {
             // For method calls, rust first does any number of autoderef, and then one
@@ -249,19 +383,19 @@ pub fn iterate_method_candidates<T>(
 
             let deref_chain = autoderef_method_receiver(db, krate, ty);
             for i in 0..deref_chain.len() {
-                if let Some(result) = iterate_method_candidates_with_autoref(
+                if iterate_method_candidates_with_autoref(
                     &deref_chain[i..],
                     db,
                     env.clone(),
                     krate,
                     traits_in_scope,
                     name,
-                    &mut callback,
+                    callback,
                 ) {
-                    return Some(result);
+                    return true;
                 }
             }
-            None
+            false
         }
         LookupMode::Path => {
             // No autoderef for path lookups
@@ -272,22 +406,22 @@ pub fn iterate_method_candidates<T>(
                 krate,
                 traits_in_scope,
                 name,
-                &mut callback,
+                callback,
             )
         }
     }
 }
 
-fn iterate_method_candidates_with_autoref<T>(
+fn iterate_method_candidates_with_autoref(
     deref_chain: &[Canonical<Ty>],
     db: &dyn HirDatabase,
     env: Arc<TraitEnvironment>,
     krate: CrateId,
     traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
-    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
-) -> Option<T> {
-    if let Some(result) = iterate_method_candidates_by_receiver(
+    mut callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
+    if iterate_method_candidates_by_receiver(
         &deref_chain[0],
         &deref_chain[1..],
         db,
@@ -297,13 +431,13 @@ fn iterate_method_candidates_with_autoref<T>(
         name,
         &mut callback,
     ) {
-        return Some(result);
+        return true;
     }
     let refed = Canonical {
-        num_vars: deref_chain[0].num_vars,
+        kinds: deref_chain[0].kinds.clone(),
         value: Ty::apply_one(TypeCtor::Ref(Mutability::Shared), deref_chain[0].value.clone()),
     };
-    if let Some(result) = iterate_method_candidates_by_receiver(
+    if iterate_method_candidates_by_receiver(
         &refed,
         deref_chain,
         db,
@@ -313,13 +447,13 @@ fn iterate_method_candidates_with_autoref<T>(
         name,
         &mut callback,
     ) {
-        return Some(result);
+        return true;
     }
     let ref_muted = Canonical {
-        num_vars: deref_chain[0].num_vars,
+        kinds: deref_chain[0].kinds.clone(),
         value: Ty::apply_one(TypeCtor::Ref(Mutability::Mut), deref_chain[0].value.clone()),
     };
-    if let Some(result) = iterate_method_candidates_by_receiver(
+    if iterate_method_candidates_by_receiver(
         &ref_muted,
         deref_chain,
         db,
@@ -329,12 +463,12 @@ fn iterate_method_candidates_with_autoref<T>(
         name,
         &mut callback,
     ) {
-        return Some(result);
+        return true;
     }
-    None
+    false
 }
 
-fn iterate_method_candidates_by_receiver<T>(
+fn iterate_method_candidates_by_receiver(
     receiver_ty: &Canonical<Ty>,
     rest_of_deref_chain: &[Canonical<Ty>],
     db: &dyn HirDatabase,
@@ -342,20 +476,18 @@ fn iterate_method_candidates_by_receiver<T>(
     krate: CrateId,
     traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
-    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
-) -> Option<T> {
+    mut callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
     // We're looking for methods with *receiver* type receiver_ty. These could
     // be found in any of the derefs of receiver_ty, so we have to go through
     // that.
     for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
-        if let Some(result) =
-            iterate_inherent_methods(self_ty, db, name, Some(receiver_ty), krate, &mut callback)
-        {
-            return Some(result);
+        if iterate_inherent_methods(self_ty, db, name, Some(receiver_ty), krate, &mut callback) {
+            return true;
         }
     }
     for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
-        if let Some(result) = iterate_trait_method_candidates(
+        if iterate_trait_method_candidates(
             self_ty,
             db,
             env.clone(),
@@ -365,40 +497,28 @@ fn iterate_method_candidates_by_receiver<T>(
             Some(receiver_ty),
             &mut callback,
         ) {
-            return Some(result);
+            return true;
         }
     }
-    None
+    false
 }
 
-fn iterate_method_candidates_for_self_ty<T>(
+fn iterate_method_candidates_for_self_ty(
     self_ty: &Canonical<Ty>,
     db: &dyn HirDatabase,
     env: Arc<TraitEnvironment>,
     krate: CrateId,
     traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
-    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
-) -> Option<T> {
-    if let Some(result) = iterate_inherent_methods(self_ty, db, name, None, krate, &mut callback) {
-        return Some(result);
-    }
-    if let Some(result) = iterate_trait_method_candidates(
-        self_ty,
-        db,
-        env,
-        krate,
-        traits_in_scope,
-        name,
-        None,
-        &mut callback,
-    ) {
-        return Some(result);
+    mut callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
+    if iterate_inherent_methods(self_ty, db, name, None, krate, &mut callback) {
+        return true;
     }
-    None
+    iterate_trait_method_candidates(self_ty, db, env, krate, traits_in_scope, name, None, callback)
 }
 
-fn iterate_trait_method_candidates<T>(
+fn iterate_trait_method_candidates(
     self_ty: &Canonical<Ty>,
     db: &dyn HirDatabase,
     env: Arc<TraitEnvironment>,
@@ -406,8 +526,8 @@ fn iterate_trait_method_candidates<T>(
     traits_in_scope: &FxHashSet<TraitId>,
     name: Option<&Name>,
     receiver_ty: Option<&Canonical<Ty>>,
-    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
-) -> Option<T> {
+    callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
     // if ty is `dyn Trait`, the trait doesn't need to be in scope
     let inherent_trait =
         self_ty.value.dyn_trait().into_iter().flat_map(|t| all_super_traits(db.upcast(), t));
@@ -440,26 +560,30 @@ fn iterate_trait_method_candidates<T>(
                 }
             }
             known_implemented = true;
-            if let Some(result) = callback(&self_ty.value, *item) {
-                return Some(result);
+            if callback(&self_ty.value, *item) {
+                return true;
             }
         }
     }
-    None
+    false
 }
 
-fn iterate_inherent_methods<T>(
+fn iterate_inherent_methods(
     self_ty: &Canonical<Ty>,
     db: &dyn HirDatabase,
     name: Option<&Name>,
     receiver_ty: Option<&Canonical<Ty>>,
     krate: CrateId,
-    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
-) -> Option<T> {
-    for krate in self_ty.value.def_crates(db, krate)? {
-        let impls = db.impls_in_crate(krate);
+    callback: &mut dyn FnMut(&Ty, AssocItemId) -> bool,
+) -> bool {
+    let def_crates = match self_ty.value.def_crates(db, krate) {
+        Some(k) => k,
+        None => return false,
+    };
+    for krate in def_crates {
+        let impls = db.inherent_impls_in_crate(krate);
 
-        for impl_def in impls.lookup_impl_defs(&self_ty.value) {
+        for &impl_def in impls.for_self_ty(&self_ty.value) {
             for &item in db.impl_data(impl_def).items.iter() {
                 if !is_valid_candidate(db, name, receiver_ty, item, self_ty) {
                     continue;
@@ -472,13 +596,13 @@ fn iterate_inherent_methods<T>(
                     test_utils::mark::hit!(impl_self_type_match_without_receiver);
                     continue;
                 }
-                if let Some(result) = callback(&self_ty.value, item) {
-                    return Some(result);
+                if callback(&self_ty.value, item) {
+                    return true;
                 }
             }
         }
     }
-    None
+    false
 }
 
 /// Returns the self type for the index trait call.
@@ -545,18 +669,19 @@ pub(crate) fn inherent_impl_substs(
     // we create a var for each type parameter of the impl; we need to keep in
     // mind here that `self_ty` might have vars of its own
     let vars = Substs::build_for_def(db, impl_id)
-        .fill_with_bound_vars(DebruijnIndex::INNERMOST, self_ty.num_vars)
+        .fill_with_bound_vars(DebruijnIndex::INNERMOST, self_ty.kinds.len())
         .build();
     let self_ty_with_vars = db.impl_self_ty(impl_id).subst(&vars);
-    let self_ty_with_vars =
-        Canonical { num_vars: vars.len() + self_ty.num_vars, value: self_ty_with_vars };
-    let substs = super::infer::unify(&self_ty_with_vars, self_ty);
+    let mut kinds = self_ty.kinds.to_vec();
+    kinds.extend(iter::repeat(TyKind::General).take(vars.len()));
+    let tys = Canonical { kinds: kinds.into(), value: (self_ty_with_vars, self_ty.value.clone()) };
+    let substs = super::infer::unify(&tys);
     // We only want the substs for the vars we added, not the ones from self_ty.
     // Also, if any of the vars we added are still in there, we replace them by
     // Unknown. I think this can only really happen if self_ty contained
     // Unknown, and in that case we want the result to contain Unknown in those
     // places again.
-    substs.map(|s| fallback_bound_vars(s.suffix(vars.len()), self_ty.num_vars))
+    substs.map(|s| fallback_bound_vars(s.suffix(vars.len()), self_ty.kinds.len()))
 }
 
 /// This replaces any 'free' Bound vars in `s` (i.e. those with indices past
@@ -616,15 +741,15 @@ fn generic_implements_goal(
     trait_: TraitId,
     self_ty: Canonical<Ty>,
 ) -> Canonical<InEnvironment<super::Obligation>> {
-    let num_vars = self_ty.num_vars;
+    let mut kinds = self_ty.kinds.to_vec();
     let substs = super::Substs::build_for_def(db, trait_)
         .push(self_ty.value)
-        .fill_with_bound_vars(DebruijnIndex::INNERMOST, num_vars)
+        .fill_with_bound_vars(DebruijnIndex::INNERMOST, kinds.len())
         .build();
-    let num_vars = substs.len() - 1 + self_ty.num_vars;
+    kinds.extend(iter::repeat(TyKind::General).take(substs.len() - 1));
     let trait_ref = TraitRef { trait_, substs };
     let obligation = super::Obligation::Trait(trait_ref);
-    Canonical { num_vars, value: InEnvironment::new(env, obligation) }
+    Canonical { kinds: kinds.into(), value: InEnvironment::new(env, obligation) }
 }
 
 fn autoderef_method_receiver(
@@ -637,9 +762,9 @@ fn autoderef_method_receiver(
     if let Some(Ty::Apply(ApplicationTy { ctor: TypeCtor::Array, parameters })) =
         deref_chain.last().map(|ty| &ty.value)
     {
-        let num_vars = deref_chain.last().unwrap().num_vars;
+        let kinds = deref_chain.last().unwrap().kinds.clone();
         let unsized_ty = Ty::apply(TypeCtor::Slice, parameters.clone());
-        deref_chain.push(Canonical { value: unsized_ty, num_vars })
+        deref_chain.push(Canonical { value: unsized_ty, kinds })
     }
     deref_chain
 }
diff --git a/crates/ra_hir_ty/src/primitive.rs b/crates/ra_hir_ty/src/primitive.rs
index 02a8179d9..37966b709 100644
--- a/crates/ra_hir_ty/src/primitive.rs
+++ b/crates/ra_hir_ty/src/primitive.rs
@@ -7,42 +7,6 @@ use std::fmt;
 
 pub use hir_def::builtin_type::{BuiltinFloat, BuiltinInt, FloatBitness, IntBitness, Signedness};
 
-#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
-pub enum Uncertain<T> {
-    Unknown,
-    Known(T),
-}
-
-impl From<IntTy> for Uncertain<IntTy> {
-    fn from(ty: IntTy) -> Self {
-        Uncertain::Known(ty)
-    }
-}
-
-impl fmt::Display for Uncertain<IntTy> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Uncertain::Unknown => write!(f, "{{integer}}"),
-            Uncertain::Known(ty) => write!(f, "{}", ty),
-        }
-    }
-}
-
-impl From<FloatTy> for Uncertain<FloatTy> {
-    fn from(ty: FloatTy) -> Self {
-        Uncertain::Known(ty)
-    }
-}
-
-impl fmt::Display for Uncertain<FloatTy> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Uncertain::Unknown => write!(f, "{{float}}"),
-            Uncertain::Known(ty) => write!(f, "{}", ty),
-        }
-    }
-}
-
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub struct IntTy {
     pub signedness: Signedness,
@@ -173,21 +137,3 @@ impl From<BuiltinFloat> for FloatTy {
         FloatTy { bitness: t.bitness }
     }
 }
-
-impl From<Option<BuiltinInt>> for Uncertain<IntTy> {
-    fn from(t: Option<BuiltinInt>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
-
-impl From<Option<BuiltinFloat>> for Uncertain<FloatTy> {
-    fn from(t: Option<BuiltinFloat>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 8498d3d96..a1714ff0f 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -1,18 +1,16 @@
 //! Database used for testing `hir`.
 
 use std::{
-    panic,
+    fmt, panic,
     sync::{Arc, Mutex},
 };
 
-use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId, ModuleId};
-use hir_expand::{db::AstDatabase, diagnostics::DiagnosticSink};
-use ra_db::{
-    salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath, SourceDatabase, Upcast,
-};
-use stdx::format_to;
-
-use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
+use hir_def::{db::DefDatabase, ModuleId};
+use hir_expand::db::AstDatabase;
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase, Upcast};
+use ra_syntax::TextRange;
+use rustc_hash::{FxHashMap, FxHashSet};
+use test_utils::extract_annotations;
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
@@ -22,10 +20,15 @@ use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
     hir_def::db::DefDatabaseStorage,
     crate::db::HirDatabaseStorage
 )]
-#[derive(Debug, Default)]
+#[derive(Default)]
 pub struct TestDB {
-    events: Mutex<Option<Vec<salsa::Event<TestDB>>>>,
-    runtime: salsa::Runtime<TestDB>,
+    storage: salsa::Storage<TestDB>,
+    events: Mutex<Option<Vec<salsa::Event>>>,
+}
+impl fmt::Debug for TestDB {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TestDB").finish()
+    }
 }
 
 impl Upcast<dyn AstDatabase> for TestDB {
@@ -41,18 +44,10 @@ impl Upcast<dyn DefDatabase> for TestDB {
 }
 
 impl salsa::Database for TestDB {
-    fn salsa_runtime(&self) -> &salsa::Runtime<TestDB> {
-        &self.runtime
-    }
-
-    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
-        &mut self.runtime
-    }
-
-    fn salsa_event(&self, event: impl Fn() -> salsa::Event<TestDB>) {
+    fn salsa_event(&self, event: salsa::Event) {
         let mut events = self.events.lock().unwrap();
         if let Some(events) = &mut *events {
-            events.push(event());
+            events.push(event);
         }
     }
 }
@@ -60,8 +55,8 @@ impl salsa::Database for TestDB {
 impl salsa::ParallelDatabase for TestDB {
     fn snapshot(&self) -> salsa::Snapshot<TestDB> {
         salsa::Snapshot::new(TestDB {
+            storage: self.storage.snapshot(),
             events: Default::default(),
-            runtime: self.runtime.snapshot(self),
         })
     }
 }
@@ -72,27 +67,16 @@ impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        extern_id: ra_db::ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl TestDB {
-    pub fn module_for_file(&self, file_id: FileId) -> ModuleId {
+    pub(crate) fn module_for_file(&self, file_id: FileId) -> ModuleId {
         for &krate in self.relevant_crates(file_id).iter() {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules.iter() {
@@ -104,67 +88,32 @@ impl TestDB {
         panic!("Can't find module for file")
     }
 
-    fn diag<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
+    pub(crate) fn extract_annotations(&self) -> FxHashMap<FileId, Vec<(TextRange, String)>> {
+        let mut files = Vec::new();
         let crate_graph = self.crate_graph();
         for krate in crate_graph.iter() {
             let crate_def_map = self.crate_def_map(krate);
-
-            let mut fns = Vec::new();
             for (module_id, _) in crate_def_map.modules.iter() {
-                for decl in crate_def_map[module_id].scope.declarations() {
-                    if let ModuleDefId::FunctionId(f) = decl {
-                        fns.push(f)
-                    }
-                }
-
-                for impl_id in crate_def_map[module_id].scope.impls() {
-                    let impl_data = self.impl_data(impl_id);
-                    for item in impl_data.items.iter() {
-                        if let AssocItemId::FunctionId(f) = item {
-                            fns.push(*f)
-                        }
-                    }
-                }
-            }
-
-            for f in fns {
-                let infer = self.infer(f.into());
-                let mut sink = DiagnosticSink::new(&mut cb);
-                infer.add_diagnostics(self, f, &mut sink);
-                let mut validator = ExprValidator::new(f, infer, &mut sink);
-                validator.validate_body(self);
+                let file_id = crate_def_map[module_id].origin.file_id();
+                files.extend(file_id)
             }
         }
-    }
-
-    pub fn diagnostics(&self) -> (String, u32) {
-        let mut buf = String::new();
-        let mut count = 0;
-        self.diag(|d| {
-            format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
-            count += 1;
-        });
-        (buf, count)
-    }
-
-    /// Like `diagnostics`, but filtered for a single diagnostic.
-    pub fn diagnostic<D: Diagnostic>(&self) -> (String, u32) {
-        let mut buf = String::new();
-        let mut count = 0;
-        self.diag(|d| {
-            // We want to filter diagnostics by the particular one we are testing for, to
-            // avoid surprising results in tests.
-            if d.downcast_ref::<D>().is_some() {
-                format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
-                count += 1;
-            };
-        });
-        (buf, count)
+        files
+            .into_iter()
+            .filter_map(|file_id| {
+                let text = self.file_text(file_id);
+                let annotations = extract_annotations(&text);
+                if annotations.is_empty() {
+                    return None;
+                }
+                Some((file_id, annotations))
+            })
+            .collect()
     }
 }
 
 impl TestDB {
-    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event<TestDB>> {
+    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
         *self.events.lock().unwrap() = Some(Vec::new());
         f();
         self.events.lock().unwrap().take().unwrap()
@@ -178,7 +127,7 @@ impl TestDB {
                 // This pretty horrible, but `Debug` is the only way to inspect
                 // QueryDescriptor at the moment.
                 salsa::EventKind::WillExecute { database_key } => {
-                    Some(format!("{:?}", database_key))
+                    Some(format!("{:?}", database_key.debug(self)))
                 }
                 _ => None,
             })
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 1fe05c70c..c972bf845 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -17,11 +17,10 @@ use hir_def::{
     item_scope::ItemScope,
     keys,
     nameres::CrateDefMap,
-    AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId, ModuleId,
+    AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
 use hir_expand::{db::AstDatabase, InFile};
-use insta::assert_snapshot;
-use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
+use ra_db::{fixture::WithFixture, FileRange, SourceDatabase, SourceDatabaseExt};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
@@ -37,21 +36,50 @@ use crate::{
 // against snapshots of the expected results using insta. Use cargo-insta to
 // update the snapshots.
 
-fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
-    type_at_pos_displayed(db, pos, |ty, _| ty.display(db).to_string())
+fn setup_tracing() -> tracing::subscriber::DefaultGuard {
+    use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
+    use tracing_tree::HierarchicalLayer;
+    let filter = EnvFilter::from_env("CHALK_DEBUG");
+    let layer = HierarchicalLayer::default()
+        .with_indent_lines(true)
+        .with_ansi(false)
+        .with_indent_amount(2)
+        .with_writer(std::io::stderr);
+    let subscriber = Registry::default().with(filter).with(layer);
+    tracing::subscriber::set_default(subscriber)
 }
 
-fn displayed_source_at_pos(db: &TestDB, pos: FilePosition) -> String {
-    type_at_pos_displayed(db, pos, |ty, module_id| ty.display_source_code(db, module_id).unwrap())
+fn check_types(ra_fixture: &str) {
+    check_types_impl(ra_fixture, false)
 }
 
-fn type_at_pos_displayed(
-    db: &TestDB,
-    pos: FilePosition,
-    display_fn: impl FnOnce(&Ty, ModuleId) -> String,
-) -> String {
+fn check_types_source_code(ra_fixture: &str) {
+    check_types_impl(ra_fixture, true)
+}
+
+fn check_types_impl(ra_fixture: &str, display_source: bool) {
+    let _tracing = setup_tracing();
+    let db = TestDB::with_files(ra_fixture);
+    let mut checked_one = false;
+    for (file_id, annotations) in db.extract_annotations() {
+        for (range, expected) in annotations {
+            let ty = type_at_range(&db, FileRange { file_id, range });
+            let actual = if display_source {
+                let module = db.module_for_file(file_id);
+                ty.display_source_code(&db, module).unwrap()
+            } else {
+                ty.display(&db).to_string()
+            };
+            assert_eq!(expected, actual);
+            checked_one = true;
+        }
+    }
+    assert!(checked_one, "no `//^` annotations found");
+}
+
+fn type_at_range(db: &TestDB, pos: FileRange) -> Ty {
     let file = db.parse(pos.file_id).ok().unwrap();
-    let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
+    let expr = algo::find_node_at_range::<ast::Expr>(file.syntax(), pos.range).unwrap();
     let fn_def = expr.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
     let module = db.module_for_file(pos.file_id);
     let func = *module.child_by_source(db)[keys::FUNCTION]
@@ -61,22 +89,17 @@ fn type_at_pos_displayed(
     let (_body, source_map) = db.body_with_source_map(func.into());
     if let Some(expr_id) = source_map.node_expr(InFile::new(pos.file_id.into(), &expr)) {
         let infer = db.infer(func.into());
-        let ty = &infer[expr_id];
-        return display_fn(ty, module);
+        return infer[expr_id].clone();
     }
     panic!("Can't find expression")
 }
 
-fn type_at(content: &str) -> String {
-    let (db, file_pos) = TestDB::with_position(content);
-    type_at_pos(&db, file_pos)
-}
-
 fn infer(ra_fixture: &str) -> String {
     infer_with_mismatches(ra_fixture, false)
 }
 
 fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
+    let _tracing = setup_tracing();
     let (db, file_id) = TestDB::with_single_file(content);
 
     let mut buf = String::new();
@@ -164,13 +187,19 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
     visit_module(&db, &crate_def_map, module.local_id, &mut |it| defs.push(it));
     defs.sort_by_key(|def| match def {
         DefWithBodyId::FunctionId(it) => {
-            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
+            let loc = it.lookup(&db);
+            let tree = db.item_tree(loc.id.file_id);
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
         DefWithBodyId::ConstId(it) => {
-            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
+            let loc = it.lookup(&db);
+            let tree = db.item_tree(loc.id.file_id);
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
         DefWithBodyId::StaticId(it) => {
-            it.lookup(&db).ast_id.to_node(&db).syntax().text_range().start()
+            let loc = it.lookup(&db);
+            let tree = db.item_tree(loc.id.file_id);
+            tree.source(&db, loc.id).syntax().text_range().start()
         }
     });
     for def in defs {
@@ -302,7 +331,7 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
     "
     .to_string();
 
-    db.query_mut(ra_db::FileTextQuery).set(pos.file_id, Arc::new(new_text));
+    db.set_file_text(pos.file_id, Arc::new(new_text));
 
     {
         let events = db.log_executed(|| {
@@ -315,237 +344,3 @@ fn typing_whitespace_inside_a_function_should_not_invalidate_types() {
         assert!(!format!("{:?}", events).contains("infer"), "{:#?}", events)
     }
 }
-
-#[test]
-fn no_such_field_diagnostics() {
-    let diagnostics = TestDB::with_files(
-        r"
-        //- /lib.rs
-        struct S { foo: i32, bar: () }
-        impl S {
-            fn new() -> S {
-                S {
-                    foo: 92,
-                    baz: 62,
-                }
-            }
-        }
-        ",
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###"
-    "baz: 62": no such field
-    "{\n            foo: 92,\n            baz: 62,\n        }": Missing structure fields:
-    - bar
-    "###
-    );
-}
-
-#[test]
-fn no_such_field_with_feature_flag_diagnostics() {
-    let diagnostics = TestDB::with_files(
-        r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        struct MyStruct {
-            my_val: usize,
-            #[cfg(feature = "foo")]
-            bar: bool,
-        }
-
-        impl MyStruct {
-            #[cfg(feature = "foo")]
-            pub(crate) fn new(my_val: usize, bar: bool) -> Self {
-                Self { my_val, bar }
-            }
-
-            #[cfg(not(feature = "foo"))]
-            pub(crate) fn new(my_val: usize, _bar: bool) -> Self {
-                Self { my_val }
-            }
-        }
-        "#,
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""###);
-}
-
-#[test]
-fn no_such_field_enum_with_feature_flag_diagnostics() {
-    let diagnostics = TestDB::with_files(
-        r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        enum Foo {
-            #[cfg(not(feature = "foo"))]
-            Buz,
-            #[cfg(feature = "foo")]
-            Bar,
-            Baz
-        }
-
-        fn test_fn(f: Foo) {
-            match f {
-                Foo::Bar => {},
-                Foo::Baz => {},
-            }
-        }
-        "#,
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""###);
-}
-
-#[test]
-fn no_such_field_with_feature_flag_diagnostics_on_struct_lit() {
-    let diagnostics = TestDB::with_files(
-        r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        struct S {
-            #[cfg(feature = "foo")]
-            foo: u32,
-            #[cfg(not(feature = "foo"))]
-            bar: u32,
-        }
-
-        impl S {
-            #[cfg(feature = "foo")]
-            fn new(foo: u32) -> Self {
-                Self { foo }
-            }
-            #[cfg(not(feature = "foo"))]
-            fn new(bar: u32) -> Self {
-                Self { bar }
-            }
-        }
-        "#,
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""###);
-}
-
-#[test]
-fn no_such_field_with_feature_flag_diagnostics_on_block_expr() {
-    let diagnostics = TestDB::with_files(
-        r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        struct S {
-            #[cfg(feature = "foo")]
-            foo: u32,
-            #[cfg(not(feature = "foo"))]
-            bar: u32,
-        }
-
-        impl S {
-            fn new(bar: u32) -> Self {
-                #[cfg(feature = "foo")]
-                {
-                Self { foo: bar }
-                }
-                #[cfg(not(feature = "foo"))]
-                {
-                Self { bar }
-                }
-            }
-        }
-        "#,
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""###);
-}
-
-#[test]
-fn no_such_field_with_feature_flag_diagnostics_on_struct_fields() {
-    let diagnostics = TestDB::with_files(
-        r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        struct S {
-            #[cfg(feature = "foo")]
-            foo: u32,
-            #[cfg(not(feature = "foo"))]
-            bar: u32,
-        }
-
-        impl S {
-            fn new(val: u32) -> Self {
-                Self {
-                    #[cfg(feature = "foo")]
-                    foo: val,
-                    #[cfg(not(feature = "foo"))]
-                    bar: val,
-                }
-            }
-        }
-        "#,
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""###);
-}
-
-#[test]
-fn missing_record_pat_field_diagnostic() {
-    let diagnostics = TestDB::with_files(
-        r"
-        //- /lib.rs
-        struct S { foo: i32, bar: () }
-        fn baz(s: S) {
-            let S { foo: _ } = s;
-        }
-        ",
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###"
-    "{ foo: _ }": Missing structure fields:
-    - bar
-    "###
-    );
-}
-
-#[test]
-fn missing_record_pat_field_no_diagnostic_if_not_exhaustive() {
-    let diagnostics = TestDB::with_files(
-        r"
-        //- /lib.rs
-        struct S { foo: i32, bar: () }
-        fn baz(s: S) -> i32 {
-            match s {
-                S { foo, .. } => foo,
-            }
-        }
-        ",
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @"");
-}
-
-#[test]
-fn break_outside_of_loop() {
-    let diagnostics = TestDB::with_files(
-        r"
-        //- /lib.rs
-        fn foo() {
-            break;
-        }
-        ",
-    )
-    .diagnostics()
-    .0;
-
-    assert_snapshot!(diagnostics, @r###""break": break outside of loop
-    "###
-    );
-}
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 6f777ed8c..d7fb6a962 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -1,7 +1,8 @@
-use super::infer_with_mismatches;
 use insta::assert_snapshot;
 use test_utils::mark;
 
+use super::infer_with_mismatches;
+
 // Infer with some common definitions and impls.
 fn infer(source: &str) -> String {
     let defs = r#"
@@ -29,10 +30,10 @@ fn test() {
 }
 "#),
         @r###"
-    11..41 '{     ...4 }; }': ()
-    21..22 'a': i32
-    30..38 '{ 1i64 }': i64
-    32..36 '1i64': i64
+    10..40 '{     ...4 }; }': ()
+    20..21 'a': i32
+    29..37 '{ 1i64 }': i64
+    31..35 '1i64': i64
     "###);
 }
 
@@ -63,50 +64,50 @@ fn test2() {
 }
 "#),
         @r###"
-    31..32 '_': &[T]
-    45..56 '{ loop {} }': T
-    47..54 'loop {}': !
-    52..54 '{}': ()
-    65..66 '_': S<&[T]>
-    82..93 '{ loop {} }': T
-    84..91 'loop {}': !
-    89..91 '{}': ()
-    122..133 '{ loop {} }': *mut [T; _]
-    124..131 'loop {}': !
-    129..131 '{}': ()
-    160..173 '{     gen() }': *mut [U]
-    166..169 'gen': fn gen<U>() -> *mut [U; _]
-    166..171 'gen()': *mut [U; _]
-    186..420 '{     ...rr); }': ()
-    196..199 'arr': &[u8; _]
-    212..216 '&[1]': &[u8; _]
-    213..216 '[1]': [u8; _]
-    214..215 '1': u8
-    227..228 'a': &[u8]
-    237..240 'arr': &[u8; _]
-    250..251 'b': u8
-    254..255 'f': fn f<u8>(&[u8]) -> u8
-    254..260 'f(arr)': u8
-    256..259 'arr': &[u8; _]
-    270..271 'c': &[u8]
-    280..287 '{ arr }': &[u8]
-    282..285 'arr': &[u8; _]
-    297..298 'd': u8
-    301..302 'g': fn g<u8>(S<&[u8]>) -> u8
-    301..316 'g(S { a: arr })': u8
-    303..315 'S { a: arr }': S<&[u8]>
-    310..313 'arr': &[u8; _]
-    326..327 'e': [&[u8]; _]
-    341..346 '[arr]': [&[u8]; _]
-    342..345 'arr': &[u8; _]
-    356..357 'f': [&[u8]; _]
-    371..379 '[arr; 2]': [&[u8]; _]
-    372..375 'arr': &[u8; _]
-    377..378 '2': usize
-    389..390 'g': (&[u8], &[u8])
-    407..417 '(arr, arr)': (&[u8], &[u8])
-    408..411 'arr': &[u8; _]
-    413..416 'arr': &[u8; _]
+    30..31 '_': &[T]
+    44..55 '{ loop {} }': T
+    46..53 'loop {}': !
+    51..53 '{}': ()
+    64..65 '_': S<&[T]>
+    81..92 '{ loop {} }': T
+    83..90 'loop {}': !
+    88..90 '{}': ()
+    121..132 '{ loop {} }': *mut [T; _]
+    123..130 'loop {}': !
+    128..130 '{}': ()
+    159..172 '{     gen() }': *mut [U]
+    165..168 'gen': fn gen<U>() -> *mut [U; _]
+    165..170 'gen()': *mut [U; _]
+    185..419 '{     ...rr); }': ()
+    195..198 'arr': &[u8; _]
+    211..215 '&[1]': &[u8; _]
+    212..215 '[1]': [u8; _]
+    213..214 '1': u8
+    226..227 'a': &[u8]
+    236..239 'arr': &[u8; _]
+    249..250 'b': u8
+    253..254 'f': fn f<u8>(&[u8]) -> u8
+    253..259 'f(arr)': u8
+    255..258 'arr': &[u8; _]
+    269..270 'c': &[u8]
+    279..286 '{ arr }': &[u8]
+    281..284 'arr': &[u8; _]
+    296..297 'd': u8
+    300..301 'g': fn g<u8>(S<&[u8]>) -> u8
+    300..315 'g(S { a: arr })': u8
+    302..314 'S { a: arr }': S<&[u8]>
+    309..312 'arr': &[u8; _]
+    325..326 'e': [&[u8]; _]
+    340..345 '[arr]': [&[u8]; _]
+    341..344 'arr': &[u8; _]
+    355..356 'f': [&[u8]; _]
+    370..378 '[arr; 2]': [&[u8]; _]
+    371..374 'arr': &[u8; _]
+    376..377 '2': usize
+    388..389 'g': (&[u8], &[u8])
+    406..416 '(arr, arr)': (&[u8], &[u8])
+    407..410 'arr': &[u8; _]
+    412..415 'arr': &[u8; _]
     "###
     );
 }
@@ -121,15 +122,15 @@ fn test() {
 }
 "#),
         @r###"
-    11..76 '{     ...[1]; }': ()
-    21..22 'x': &[isize]
-    35..39 '&[1]': &[isize; _]
-    36..39 '[1]': [isize; _]
-    37..38 '1': isize
-    49..50 'x': *const [isize]
-    69..73 '&[1]': &[isize; _]
-    70..73 '[1]': [isize; _]
-    71..72 '1': isize
+    10..75 '{     ...[1]; }': ()
+    20..21 'x': &[isize]
+    34..38 '&[1]': &[isize; _]
+    35..38 '[1]': [isize; _]
+    36..37 '1': isize
+    48..49 'x': *const [isize]
+    68..72 '&[1]': &[isize; _]
+    69..72 '[1]': [isize; _]
+    70..71 '1': isize
     "###);
 }
 
@@ -155,31 +156,31 @@ fn test(a: A<[u8; 2]>, b: B<[u8; 2]>, c: C<[u8; 2]>) {
 }
 "#),
         @r###"
-    258..259 'x': A<[T]>
-    279..284 '{ x }': A<[T]>
-    281..282 'x': A<[T]>
-    296..297 'x': B<[T]>
-    317..322 '{ x }': B<[T]>
-    319..320 'x': B<[T]>
-    334..335 'x': C<[T]>
-    355..360 '{ x }': C<[T]>
-    357..358 'x': C<[T]>
-    370..371 'a': A<[u8; _]>
-    385..386 'b': B<[u8; _]>
-    400..401 'c': C<[u8; _]>
-    415..481 '{     ...(c); }': ()
-    425..426 'd': A<[{unknown}]>
-    429..433 'foo1': fn foo1<{unknown}>(A<[{unknown}]>) -> A<[{unknown}]>
-    429..436 'foo1(a)': A<[{unknown}]>
-    434..435 'a': A<[u8; _]>
-    446..447 'e': B<[u8]>
-    450..454 'foo2': fn foo2<u8>(B<[u8]>) -> B<[u8]>
-    450..457 'foo2(b)': B<[u8]>
-    455..456 'b': B<[u8; _]>
-    467..468 'f': C<[u8]>
-    471..475 'foo3': fn foo3<u8>(C<[u8]>) -> C<[u8]>
-    471..478 'foo3(c)': C<[u8]>
-    476..477 'c': C<[u8; _]>
+    257..258 'x': A<[T]>
+    278..283 '{ x }': A<[T]>
+    280..281 'x': A<[T]>
+    295..296 'x': B<[T]>
+    316..321 '{ x }': B<[T]>
+    318..319 'x': B<[T]>
+    333..334 'x': C<[T]>
+    354..359 '{ x }': C<[T]>
+    356..357 'x': C<[T]>
+    369..370 'a': A<[u8; _]>
+    384..385 'b': B<[u8; _]>
+    399..400 'c': C<[u8; _]>
+    414..480 '{     ...(c); }': ()
+    424..425 'd': A<[{unknown}]>
+    428..432 'foo1': fn foo1<{unknown}>(A<[{unknown}]>) -> A<[{unknown}]>
+    428..435 'foo1(a)': A<[{unknown}]>
+    433..434 'a': A<[u8; _]>
+    445..446 'e': B<[u8]>
+    449..453 'foo2': fn foo2<u8>(B<[u8]>) -> B<[u8]>
+    449..456 'foo2(b)': B<[u8]>
+    454..455 'b': B<[u8; _]>
+    466..467 'f': C<[u8]>
+    470..474 'foo3': fn foo3<u8>(C<[u8]>) -> C<[u8]>
+    470..477 'foo3(c)': C<[u8]>
+    475..476 'c': C<[u8; _]>
     "###
     );
 }
@@ -198,24 +199,24 @@ fn test() {
 }
 "#),
         @r###"
-    11..12 'x': &[T]
-    28..39 '{ loop {} }': &[T]
-    30..37 'loop {}': !
-    35..37 '{}': ()
-    50..126 '{     ...  }; }': ()
-    60..61 'x': &[i32]
-    64..123 'if tru...     }': &[i32]
-    67..71 'true': bool
-    72..97 '{     ...     }': &[i32]
-    82..85 'foo': fn foo<i32>(&[i32]) -> &[i32]
-    82..91 'foo(&[1])': &[i32]
-    86..90 '&[1]': &[i32; _]
-    87..90 '[1]': [i32; _]
-    88..89 '1': i32
-    103..123 '{     ...     }': &[i32; _]
-    113..117 '&[1]': &[i32; _]
-    114..117 '[1]': [i32; _]
-    115..116 '1': i32
+    10..11 'x': &[T]
+    27..38 '{ loop {} }': &[T]
+    29..36 'loop {}': !
+    34..36 '{}': ()
+    49..125 '{     ...  }; }': ()
+    59..60 'x': &[i32]
+    63..122 'if tru...     }': &[i32]
+    66..70 'true': bool
+    71..96 '{     ...     }': &[i32]
+    81..84 'foo': fn foo<i32>(&[i32]) -> &[i32]
+    81..90 'foo(&[1])': &[i32]
+    85..89 '&[1]': &[i32; _]
+    86..89 '[1]': [i32; _]
+    87..88 '1': i32
+    102..122 '{     ...     }': &[i32; _]
+    112..116 '&[1]': &[i32; _]
+    113..116 '[1]': [i32; _]
+    114..115 '1': i32
     "###
     );
 }
@@ -234,24 +235,24 @@ fn test() {
 }
 "#),
         @r###"
-    11..12 'x': &[T]
-    28..39 '{ loop {} }': &[T]
-    30..37 'loop {}': !
-    35..37 '{}': ()
-    50..126 '{     ...  }; }': ()
-    60..61 'x': &[i32]
-    64..123 'if tru...     }': &[i32]
-    67..71 'true': bool
-    72..92 '{     ...     }': &[i32; _]
-    82..86 '&[1]': &[i32; _]
-    83..86 '[1]': [i32; _]
-    84..85 '1': i32
-    98..123 '{     ...     }': &[i32]
-    108..111 'foo': fn foo<i32>(&[i32]) -> &[i32]
-    108..117 'foo(&[1])': &[i32]
-    112..116 '&[1]': &[i32; _]
-    113..116 '[1]': [i32; _]
-    114..115 '1': i32
+    10..11 'x': &[T]
+    27..38 '{ loop {} }': &[T]
+    29..36 'loop {}': !
+    34..36 '{}': ()
+    49..125 '{     ...  }; }': ()
+    59..60 'x': &[i32]
+    63..122 'if tru...     }': &[i32]
+    66..70 'true': bool
+    71..91 '{     ...     }': &[i32; _]
+    81..85 '&[1]': &[i32; _]
+    82..85 '[1]': [i32; _]
+    83..84 '1': i32
+    97..122 '{     ...     }': &[i32]
+    107..110 'foo': fn foo<i32>(&[i32]) -> &[i32]
+    107..116 'foo(&[1])': &[i32]
+    111..115 '&[1]': &[i32; _]
+    112..115 '[1]': [i32; _]
+    113..114 '1': i32
     "###
     );
 }
@@ -270,31 +271,31 @@ fn test(i: i32) {
 }
 "#),
         @r###"
-    11..12 'x': &[T]
-    28..39 '{ loop {} }': &[T]
-    30..37 'loop {}': !
-    35..37 '{}': ()
-    48..49 'i': i32
-    56..150 '{     ...  }; }': ()
-    66..67 'x': &[i32]
-    70..147 'match ...     }': &[i32]
-    76..77 'i': i32
-    88..89 '2': i32
-    88..89 '2': i32
-    93..96 'foo': fn foo<i32>(&[i32]) -> &[i32]
-    93..102 'foo(&[2])': &[i32]
-    97..101 '&[2]': &[i32; _]
-    98..101 '[2]': [i32; _]
-    99..100 '2': i32
-    112..113 '1': i32
-    112..113 '1': i32
-    117..121 '&[1]': &[i32; _]
-    118..121 '[1]': [i32; _]
-    119..120 '1': i32
-    131..132 '_': i32
-    136..140 '&[3]': &[i32; _]
-    137..140 '[3]': [i32; _]
-    138..139 '3': i32
+    10..11 'x': &[T]
+    27..38 '{ loop {} }': &[T]
+    29..36 'loop {}': !
+    34..36 '{}': ()
+    47..48 'i': i32
+    55..149 '{     ...  }; }': ()
+    65..66 'x': &[i32]
+    69..146 'match ...     }': &[i32]
+    75..76 'i': i32
+    87..88 '2': i32
+    87..88 '2': i32
+    92..95 'foo': fn foo<i32>(&[i32]) -> &[i32]
+    92..101 'foo(&[2])': &[i32]
+    96..100 '&[2]': &[i32; _]
+    97..100 '[2]': [i32; _]
+    98..99 '2': i32
+    111..112 '1': i32
+    111..112 '1': i32
+    116..120 '&[1]': &[i32; _]
+    117..120 '[1]': [i32; _]
+    118..119 '1': i32
+    130..131 '_': i32
+    135..139 '&[3]': &[i32; _]
+    136..139 '[3]': [i32; _]
+    137..138 '3': i32
     "###
     );
 }
@@ -313,31 +314,31 @@ fn test(i: i32) {
 }
 "#),
         @r###"
-    11..12 'x': &[T]
-    28..39 '{ loop {} }': &[T]
-    30..37 'loop {}': !
-    35..37 '{}': ()
-    48..49 'i': i32
-    56..150 '{     ...  }; }': ()
-    66..67 'x': &[i32]
-    70..147 'match ...     }': &[i32]
-    76..77 'i': i32
-    88..89 '1': i32
-    88..89 '1': i32
-    93..97 '&[1]': &[i32; _]
-    94..97 '[1]': [i32; _]
-    95..96 '1': i32
-    107..108 '2': i32
-    107..108 '2': i32
-    112..115 'foo': fn foo<i32>(&[i32]) -> &[i32]
-    112..121 'foo(&[2])': &[i32]
-    116..120 '&[2]': &[i32; _]
-    117..120 '[2]': [i32; _]
-    118..119 '2': i32
-    131..132 '_': i32
-    136..140 '&[3]': &[i32; _]
-    137..140 '[3]': [i32; _]
-    138..139 '3': i32
+    10..11 'x': &[T]
+    27..38 '{ loop {} }': &[T]
+    29..36 'loop {}': !
+    34..36 '{}': ()
+    47..48 'i': i32
+    55..149 '{     ...  }; }': ()
+    65..66 'x': &[i32]
+    69..146 'match ...     }': &[i32]
+    75..76 'i': i32
+    87..88 '1': i32
+    87..88 '1': i32
+    92..96 '&[1]': &[i32; _]
+    93..96 '[1]': [i32; _]
+    94..95 '1': i32
+    106..107 '2': i32
+    106..107 '2': i32
+    111..114 'foo': fn foo<i32>(&[i32]) -> &[i32]
+    111..120 'foo(&[2])': &[i32]
+    115..119 '&[2]': &[i32; _]
+    116..119 '[2]': [i32; _]
+    117..118 '2': i32
+    130..131 '_': i32
+    135..139 '&[3]': &[i32; _]
+    136..139 '[3]': [i32; _]
+    137..138 '3': i32
     "###
     );
 }
@@ -358,24 +359,24 @@ fn test() {
 }
 "#),
         @r###"
-    11..145 '{     ...  }; }': ()
-    21..22 't': &mut i32
-    25..31 '&mut 1': &mut i32
-    30..31 '1': i32
-    41..42 'x': *const i32
-    45..142 'match ...     }': *const i32
-    51..52 '1': i32
-    63..64 '1': i32
-    63..64 '1': i32
-    68..69 't': &mut i32
-    68..81 't as *mut i32': *mut i32
-    91..92 '2': i32
-    91..92 '2': i32
-    96..97 't': &mut i32
-    96..105 't as &i32': &i32
-    115..116 '_': i32
-    120..121 't': &mut i32
-    120..135 't as *const i32': *const i32
+    10..144 '{     ...  }; }': ()
+    20..21 't': &mut i32
+    24..30 '&mut 1': &mut i32
+    29..30 '1': i32
+    40..41 'x': *const i32
+    44..141 'match ...     }': *const i32
+    50..51 '1': i32
+    62..63 '1': i32
+    62..63 '1': i32
+    67..68 't': &mut i32
+    67..80 't as *mut i32': *mut i32
+    90..91 '2': i32
+    90..91 '2': i32
+    95..96 't': &mut i32
+    95..104 't as &i32': &i32
+    114..115 '_': i32
+    119..120 't': &mut i32
+    119..134 't as *const i32': *const i32
     "###
     );
 }
@@ -389,9 +390,9 @@ fn foo() -> u32 {
 }
 "#, true),
         @r###"
-    17..40 '{     ...own; }': u32
-    23..37 'return unknown': !
-    30..37 'unknown': u32
+    16..39 '{     ...own; }': u32
+    22..36 'return unknown': !
+    29..36 'unknown': u32
     "###
     );
 }
@@ -409,24 +410,24 @@ fn test() {
 }
 "#, true),
         @r###"
-    30..31 'x': &Foo
-    39..41 '{}': ()
-    52..133 '{     ...oo); }': ()
-    58..71 'takes_ref_foo': fn takes_ref_foo(&Foo)
-    58..77 'takes_...(&Foo)': ()
-    72..76 '&Foo': &Foo
-    73..76 'Foo': Foo
-    83..96 'takes_ref_foo': fn takes_ref_foo(&Foo)
-    83..103 'takes_...&&Foo)': ()
-    97..102 '&&Foo': &&Foo
-    98..102 '&Foo': &Foo
-    99..102 'Foo': Foo
-    109..122 'takes_ref_foo': fn takes_ref_foo(&Foo)
-    109..130 'takes_...&&Foo)': ()
-    123..129 '&&&Foo': &&&Foo
-    124..129 '&&Foo': &&Foo
-    125..129 '&Foo': &Foo
-    126..129 'Foo': Foo
+    29..30 'x': &Foo
+    38..40 '{}': ()
+    51..132 '{     ...oo); }': ()
+    57..70 'takes_ref_foo': fn takes_ref_foo(&Foo)
+    57..76 'takes_...(&Foo)': ()
+    71..75 '&Foo': &Foo
+    72..75 'Foo': Foo
+    82..95 'takes_ref_foo': fn takes_ref_foo(&Foo)
+    82..102 'takes_...&&Foo)': ()
+    96..101 '&&Foo': &&Foo
+    97..101 '&Foo': &Foo
+    98..101 'Foo': Foo
+    108..121 'takes_ref_foo': fn takes_ref_foo(&Foo)
+    108..129 'takes_...&&Foo)': ()
+    122..128 '&&&Foo': &&&Foo
+    123..128 '&&Foo': &&Foo
+    124..128 '&Foo': &Foo
+    125..128 'Foo': Foo
     "###
     );
 }
@@ -444,26 +445,26 @@ fn test() {
 }
 "#, true),
         @r###"
-    29..30 'x': &T
-    41..47 '{ *x }': T
-    43..45 '*x': T
-    44..45 'x': &T
-    58..127 '{     ...oo); }': ()
-    64..73 'takes_ref': fn takes_ref<Foo>(&Foo) -> Foo
-    64..79 'takes_ref(&Foo)': Foo
-    74..78 '&Foo': &Foo
-    75..78 'Foo': Foo
-    85..94 'takes_ref': fn takes_ref<&Foo>(&&Foo) -> &Foo
-    85..101 'takes_...&&Foo)': &Foo
-    95..100 '&&Foo': &&Foo
-    96..100 '&Foo': &Foo
-    97..100 'Foo': Foo
-    107..116 'takes_ref': fn takes_ref<&&Foo>(&&&Foo) -> &&Foo
-    107..124 'takes_...&&Foo)': &&Foo
-    117..123 '&&&Foo': &&&Foo
-    118..123 '&&Foo': &&Foo
-    119..123 '&Foo': &Foo
-    120..123 'Foo': Foo
+    28..29 'x': &T
+    40..46 '{ *x }': T
+    42..44 '*x': T
+    43..44 'x': &T
+    57..126 '{     ...oo); }': ()
+    63..72 'takes_ref': fn takes_ref<Foo>(&Foo) -> Foo
+    63..78 'takes_ref(&Foo)': Foo
+    73..77 '&Foo': &Foo
+    74..77 'Foo': Foo
+    84..93 'takes_ref': fn takes_ref<&Foo>(&&Foo) -> &Foo
+    84..100 'takes_...&&Foo)': &Foo
+    94..99 '&&Foo': &&Foo
+    95..99 '&Foo': &Foo
+    96..99 'Foo': Foo
+    106..115 'takes_ref': fn takes_ref<&&Foo>(&&&Foo) -> &&Foo
+    106..123 'takes_...&&Foo)': &&Foo
+    116..122 '&&&Foo': &&&Foo
+    117..122 '&&Foo': &&Foo
+    118..122 '&Foo': &Foo
+    119..122 'Foo': Foo
     "###
     );
 }
@@ -483,18 +484,18 @@ fn test() {
 }
 "#, true),
         @r###"
-    127..128 'x': &str
-    136..138 '{}': ()
-    169..180 '{ loop {} }': String
-    171..178 'loop {}': !
-    176..178 '{}': ()
-    191..236 '{     ... }); }': ()
-    197..210 'takes_ref_str': fn takes_ref_str(&str)
-    197..233 'takes_...g() })': ()
-    211..232 '&{ ret...ng() }': &String
-    212..232 '{ retu...ng() }': String
-    214..228 'returns_string': fn returns_string() -> String
-    214..230 'return...ring()': String
+    126..127 'x': &str
+    135..137 '{}': ()
+    168..179 '{ loop {} }': String
+    170..177 'loop {}': !
+    175..177 '{}': ()
+    190..235 '{     ... }); }': ()
+    196..209 'takes_ref_str': fn takes_ref_str(&str)
+    196..232 'takes_...g() })': ()
+    210..231 '&{ ret...ng() }': &String
+    211..231 '{ retu...ng() }': String
+    213..227 'returns_string': fn returns_string() -> String
+    213..229 'return...ring()': String
     "###
     );
 }
@@ -513,19 +514,19 @@ fn foo() {
 }
 "#, true),
         @r###"
-    10..106 '{     ...  }; }': ()
-    20..21 'x': || -> &u32
-    24..103 '|| {  ...     }': || -> &u32
-    27..103 '{     ...     }': &u32
-    37..82 'if tru...     }': ()
-    40..44 'true': bool
-    45..82 '{     ...     }': ()
-    59..71 'return &1u32': !
-    66..71 '&1u32': &u32
-    67..71 '1u32': u32
-    91..97 '&&1u32': &&u32
-    92..97 '&1u32': &u32
-    93..97 '1u32': u32
+    9..105 '{     ...  }; }': ()
+    19..20 'x': || -> &u32
+    23..102 '|| {  ...     }': || -> &u32
+    26..102 '{     ...     }': &u32
+    36..81 'if tru...     }': ()
+    39..43 'true': bool
+    44..81 '{     ...     }': ()
+    58..70 'return &1u32': !
+    65..70 '&1u32': &u32
+    66..70 '1u32': u32
+    90..96 '&&1u32': &&u32
+    91..96 '&1u32': &u32
+    92..96 '1u32': u32
     "###
     );
 }
@@ -540,12 +541,12 @@ fn test() {
 }
 "#, true),
         @r###"
-    8..9 'x': u32
-    25..30 '{ 1 }': isize
-    27..28 '1': isize
-    41..79 '{     ...foo; }': ()
-    51..52 'f': fn(u32) -> isize
-    73..76 'foo': fn foo(u32) -> isize
+    7..8 'x': u32
+    24..29 '{ 1 }': isize
+    26..27 '1': isize
+    40..78 '{     ...foo; }': ()
+    50..51 'f': fn(u32) -> isize
+    72..75 'foo': fn foo(u32) -> isize
     "###
     );
 }
@@ -567,27 +568,27 @@ fn test() {
 }
 "#, true),
         @r###"
-    9..10 'x': u32
-    26..31 '{ 1 }': isize
-    28..29 '1': isize
-    40..41 'x': u32
-    57..62 '{ 2 }': isize
-    59..60 '2': isize
-    71..72 'x': u32
-    88..93 '{ 3 }': isize
-    90..91 '3': isize
-    104..193 '{     ...  }; }': ()
-    114..115 'x': fn(u32) -> isize
-    118..190 'match ...     }': fn(u32) -> isize
-    124..125 '1': i32
-    136..137 '1': i32
-    136..137 '1': i32
-    141..145 'foo1': fn foo1(u32) -> isize
-    155..156 '2': i32
-    155..156 '2': i32
-    160..164 'foo2': fn foo2(u32) -> isize
-    174..175 '_': i32
-    179..183 'foo3': fn foo3(u32) -> isize
+    8..9 'x': u32
+    25..30 '{ 1 }': isize
+    27..28 '1': isize
+    39..40 'x': u32
+    56..61 '{ 2 }': isize
+    58..59 '2': isize
+    70..71 'x': u32
+    87..92 '{ 3 }': isize
+    89..90 '3': isize
+    103..192 '{     ...  }; }': ()
+    113..114 'x': fn(u32) -> isize
+    117..189 'match ...     }': fn(u32) -> isize
+    123..124 '1': i32
+    135..136 '1': i32
+    135..136 '1': i32
+    140..144 'foo1': fn foo1(u32) -> isize
+    154..155 '2': i32
+    154..155 '2': i32
+    159..163 'foo2': fn foo2(u32) -> isize
+    173..174 '_': i32
+    178..182 'foo3': fn foo3(u32) -> isize
     "###
     );
 }
@@ -601,12 +602,12 @@ fn test() {
 }
 "#, true),
         @r###"
-    11..55 '{     ...1 }; }': ()
-    21..22 'f': fn(u32) -> isize
-    43..52 '|x| { 1 }': |u32| -> isize
-    44..45 'x': u32
-    47..52 '{ 1 }': isize
-    49..50 '1': isize
+    10..54 '{     ...1 }; }': ()
+    20..21 'f': fn(u32) -> isize
+    42..51 '|x| { 1 }': |u32| -> isize
+    43..44 'x': u32
+    46..51 '{ 1 }': isize
+    48..49 '1': isize
     "###
     );
 }
@@ -624,11 +625,11 @@ impl<TT> S<TT> {
 }
 "#, true),
         @r###"
-    51..55 'self': &S<TT>
-    64..87 '{     ...     }': &TT
-    74..81 '&self.t': &TT
-    75..79 'self': &S<TT>
-    75..81 'self.t': TT
+    50..54 'self': &S<TT>
+    63..86 '{     ...     }': &TT
+    73..80 '&self.t': &TT
+    74..78 'self': &S<TT>
+    74..80 'self.t': TT
     "###
     );
 }
@@ -649,21 +650,69 @@ fn test() {
 }
 "#, true),
         @r###"
-    162..199 '{     ... 3]; }': ()
-    172..173 'f': &[usize]
-    186..196 '&[1, 2, 3]': &[usize; _]
-    187..196 '[1, 2, 3]': [usize; _]
-    188..189 '1': usize
-    191..192 '2': usize
-    194..195 '3': usize
+    161..198 '{     ... 3]; }': ()
+    171..172 'f': &[usize]
+    185..195 '&[1, 2, 3]': &[usize; _]
+    186..195 '[1, 2, 3]': [usize; _]
+    187..188 '1': usize
+    190..191 '2': usize
+    193..194 '3': usize
+    "###
+    );
+}
+
+#[test]
+fn coerce_unsize_trait_object_simple() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+#[lang = "sized"]
+pub trait Sized {}
+#[lang = "unsize"]
+pub trait Unsize<T> {}
+#[lang = "coerce_unsized"]
+pub trait CoerceUnsized<T> {}
+
+impl<T: Unsize<U>, U> CoerceUnsized<&U> for &T {}
+
+trait Foo<T, U> {}
+trait Bar<U, T, X>: Foo<T, U> {}
+trait Baz<T, X>: Bar<usize, T, X> {}
+
+struct S<T, X>;
+impl<T, X> Foo<T, usize> for S<T, X> {}
+impl<T, X> Bar<usize, T, X> for S<T, X> {}
+impl<T, X> Baz<T, X> for S<T, X> {}
+
+fn test() {
+    let obj: &dyn Baz<i8, i16> = &S;
+    let obj: &dyn Bar<_, i8, i16> = &S;
+    let obj: &dyn Foo<i8, _> = &S;
+}
+"#, true),
+        @r###"
+    424..539 '{     ... &S; }': ()
+    434..437 'obj': &dyn Baz<i8, i16>
+    459..461 '&S': &S<i8, i16>
+    460..461 'S': S<i8, i16>
+    471..474 'obj': &dyn Bar<usize, i8, i16>
+    499..501 '&S': &S<i8, i16>
+    500..501 'S': S<i8, i16>
+    511..514 'obj': &dyn Foo<i8, usize>
+    534..536 '&S': &S<i8, {unknown}>
+    535..536 'S': S<i8, {unknown}>
     "###
     );
 }
 
 #[test]
-fn coerce_unsize_trait_object() {
+// The rust reference says this should be possible, but rustc doesn't implement
+// it. We used to support it, but Chalk doesn't.
+#[ignore]
+fn coerce_unsize_trait_object_to_trait_object() {
     assert_snapshot!(
         infer_with_mismatches(r#"
+#[lang = "sized"]
+pub trait Sized {}
 #[lang = "unsize"]
 pub trait Unsize<T> {}
 #[lang = "coerce_unsized"]
@@ -689,19 +738,19 @@ fn test() {
 }
 "#, true),
         @r###"
-    388..573 '{     ...bj2; }': ()
-    398..401 'obj': &dyn Baz<i8, i16>
-    423..425 '&S': &S<i8, i16>
-    424..425 'S': S<i8, i16>
-    435..438 'obj': &dyn Bar<usize, i8, i16>
-    460..463 'obj': &dyn Baz<i8, i16>
-    473..476 'obj': &dyn Foo<i8, usize>
-    495..498 'obj': &dyn Bar<usize, i8, i16>
-    508..512 'obj2': &dyn Baz<i8, i16>
-    534..536 '&S': &S<i8, i16>
-    535..536 'S': S<i8, i16>
-    546..547 '_': &dyn Foo<i8, usize>
-    566..570 'obj2': &dyn Baz<i8, i16>
+    424..609 '{     ...bj2; }': ()
+    434..437 'obj': &dyn Baz<i8, i16>
+    459..461 '&S': &S<i8, i16>
+    460..461 'S': S<i8, i16>
+    471..474 'obj': &dyn Bar<usize, i8, i16>
+    496..499 'obj': &dyn Baz<i8, i16>
+    509..512 'obj': &dyn Foo<i8, usize>
+    531..534 'obj': &dyn Bar<usize, i8, i16>
+    544..548 'obj2': &dyn Baz<i8, i16>
+    570..572 '&S': &S<i8, i16>
+    571..572 'S': S<i8, i16>
+    582..583 '_': &dyn Foo<i8, usize>
+    602..606 'obj2': &dyn Baz<i8, i16>
     "###
     );
 }
@@ -710,6 +759,8 @@ fn test() {
 fn coerce_unsize_super_trait_cycle() {
     assert_snapshot!(
         infer_with_mismatches(r#"
+#[lang = "sized"]
+pub trait Sized {}
 #[lang = "unsize"]
 pub trait Unsize<T> {}
 #[lang = "coerce_unsized"]
@@ -730,16 +781,17 @@ impl D for S {}
 
 fn test() {
     let obj: &dyn D = &S;
-    let obj: &dyn A = obj;
+    let obj: &dyn A = &S;
 }
 "#, true),
         @r###"
-    292..348 '{     ...obj; }': ()
-    302..305 'obj': &dyn D
-    316..318 '&S': &S
-    317..318 'S': S
-    328..331 'obj': &dyn A
-    342..345 'obj': &dyn D
+    328..383 '{     ... &S; }': ()
+    338..341 'obj': &dyn D
+    352..354 '&S': &S
+    353..354 'S': S
+    364..367 'obj': &dyn A
+    378..380 '&S': &S
+    379..380 'S': S
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/display_source_code.rs b/crates/ra_hir_ty/src/tests/display_source_code.rs
index 4088b1d22..b502135d8 100644
--- a/crates/ra_hir_ty/src/tests/display_source_code.rs
+++ b/crates/ra_hir_ty/src/tests/display_source_code.rs
@@ -1,50 +1,41 @@
-use super::displayed_source_at_pos;
-use crate::test_db::TestDB;
-use ra_db::fixture::WithFixture;
+use super::check_types_source_code;
 
 #[test]
 fn qualify_path_to_submodule() {
-    let (db, pos) = TestDB::with_position(
+    check_types_source_code(
         r#"
-//- /main.rs
-
 mod foo {
     pub struct Foo;
 }
 
 fn bar() {
     let foo: foo::Foo = foo::Foo;
-    foo<|>
-}
+    foo
+}  //^ foo::Foo
 
 "#,
     );
-    assert_eq!("foo::Foo", displayed_source_at_pos(&db, pos));
 }
 
 #[test]
 fn omit_default_type_parameters() {
-    let (db, pos) = TestDB::with_position(
-        r"
-        //- /main.rs
-        struct Foo<T = u8> { t: T }
-        fn main() {
-            let foo = Foo { t: 5 };
-            foo<|>;
-        }
-        ",
+    check_types_source_code(
+        r#"
+struct Foo<T = u8> { t: T }
+fn main() {
+    let foo = Foo { t: 5u8 };
+    foo;
+}  //^ Foo
+"#,
     );
-    assert_eq!("Foo", displayed_source_at_pos(&db, pos));
 
-    let (db, pos) = TestDB::with_position(
-        r"
-        //- /main.rs
-        struct Foo<K, T = u8> { k: K, t: T }
-        fn main() {
-            let foo = Foo { k: 400, t: 5 };
-            foo<|>;
-        }
-        ",
+    check_types_source_code(
+        r#"
+struct Foo<K, T = u8> { k: K, t: T }
+fn main() {
+    let foo = Foo { k: 400, t: 5u8 };
+    foo;
+}   //^ Foo<i32>
+"#,
     );
-    assert_eq!("Foo<i32>", displayed_source_at_pos(&db, pos));
 }
diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
index 4c6099aa2..45c4e309e 100644
--- a/crates/ra_hir_ty/src/tests/macros.rs
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -1,16 +1,13 @@
 use std::fs;
 
 use insta::assert_snapshot;
-use ra_db::fixture::WithFixture;
 use test_utils::project_dir;
 
-use crate::test_db::TestDB;
-
-use super::{infer, type_at, type_at_pos};
+use super::{check_types, infer};
 
 #[test]
 fn cfg_impl_def() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:foo cfg:test
 use foo::S as T;
@@ -28,8 +25,8 @@ impl S {
 
 fn test() {
     let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
-    t<|>;
-}
+    t;
+} //^ (i32, {unknown}, i32, {unknown})
 
 //- /foo.rs crate:foo
 struct S;
@@ -45,7 +42,6 @@ impl S {
 }
 "#,
     );
-    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -71,8 +67,8 @@ fn main() {
     !1..4 'Foo': Foo({unknown}) -> Foo
     !1..16 'Foo(vec![1,2,])': Foo
     !5..15 'vec![1,2,]': {unknown}
-    156..182 '{     ...,2); }': ()
-    166..167 'x': Foo
+    155..181 '{     ...,2); }': ()
+    165..166 'x': Foo
     "###
     );
 }
@@ -104,10 +100,10 @@ fn main() {
     !1..4 'Foo': Foo({unknown}) -> Foo
     !1..16 'Foo(vec![1,2,])': Foo
     !5..15 'vec![1,2,]': {unknown}
-    195..251 '{     ...,2); }': ()
-    205..206 'x': Foo
-    228..229 'y': {unknown}
-    232..248 'crate:...!(1,2)': {unknown}
+    194..250 '{     ...,2); }': ()
+    204..205 'x': Foo
+    227..228 'y': {unknown}
+    231..247 'crate:...!(1,2)': {unknown}
     "###
     );
 }
@@ -133,9 +129,9 @@ fn main() {
         @r###"
     !0..5 '42i32': i32
     !0..5 '42i32': i32
-    111..164 '{     ...!(); }': ()
-    121..122 'x': i32
-    148..149 'y': i32
+    110..163 '{     ...!(); }': ()
+    120..121 'x': i32
+    147..148 'y': i32
     "###
     );
 }
@@ -197,26 +193,26 @@ fn spam() {
     !0..6 '1isize': isize
     !0..6 '1isize': isize
     !0..6 '1isize': isize
-    54..457 '{     ...!(); }': ()
-    88..109 'spam!(...am!())': {unknown}
-    115..134 'for _ ...!() {}': ()
-    119..120 '_': {unknown}
-    132..134 '{}': ()
-    139..149 '|| spam!()': || -> isize
-    155..171 'while ...!() {}': ()
-    169..171 '{}': ()
-    176..189 'break spam!()': !
-    195..209 'return spam!()': !
-    215..269 'match ...     }': isize
-    239..240 '_': isize
-    274..290 'spam!(...am!())': {unknown}
-    296..318 'Spam {...m!() }': {unknown}
-    324..340 'spam!(...am!()]': {unknown}
-    365..381 'spam!(... usize': usize
-    387..395 '&spam!()': &isize
-    401..409 '-spam!()': isize
-    415..431 'spam!(...pam!()': {unknown}
-    437..454 'spam!(...pam!()': isize
+    53..456 '{     ...!(); }': ()
+    87..108 'spam!(...am!())': {unknown}
+    114..133 'for _ ...!() {}': ()
+    118..119 '_': {unknown}
+    131..133 '{}': ()
+    138..148 '|| spam!()': || -> isize
+    154..170 'while ...!() {}': ()
+    168..170 '{}': ()
+    175..188 'break spam!()': !
+    194..208 'return spam!()': !
+    214..268 'match ...     }': isize
+    238..239 '_': isize
+    273..289 'spam!(...am!())': {unknown}
+    295..317 'Spam {...m!() }': {unknown}
+    323..339 'spam!(...am!()]': {unknown}
+    364..380 'spam!(... usize': usize
+    386..394 '&spam!()': &isize
+    400..408 '-spam!()': isize
+    414..430 'spam!(...pam!()': {unknown}
+    436..453 'spam!(...pam!()': isize
     "###
     );
 }
@@ -245,34 +241,32 @@ fn foo() {
 "#),
         @r###"
     !0..5 '42i32': i32
-    171..206 '{     ...32); }': ()
-    181..184 'foo': i32
+    170..205 '{     ...32); }': ()
+    180..183 'foo': i32
     "###
     );
 }
 
 #[test]
 fn processes_impls_generated_by_macros() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 macro_rules! m {
     ($ident:ident) => (impl Trait for $ident {})
 }
 trait Trait { fn foo(self) -> u128 {} }
 struct S;
 m!(S);
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn infer_assoc_items_generated_by_macros() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 macro_rules! m {
     () => (fn foo(&self) -> u128 {0})
 }
@@ -281,17 +275,16 @@ impl S {
     m!();
 }
 
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn infer_assoc_items_generated_by_macros_chain() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 macro_rules! m_inner {
     () => {fn foo(&self) -> u128 {0}}
 }
@@ -304,21 +297,21 @@ impl S {
     m!();
 }
 
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn infer_macro_with_dollar_crate_is_correct_in_expr() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:foo
 fn test() {
     let x = (foo::foo!(1), foo::foo!(2));
-    x<|>;
-}
+    x;
+} //^ (i32, usize)
 
 //- /lib.rs crate:foo
 #[macro_export]
@@ -335,12 +328,11 @@ macro_rules! bar {
 pub fn baz() -> usize { 31usize }
 "#,
     );
-    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_macro_with_dollar_crate_is_correct_in_trait_associate_type() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:foo
 use foo::Trait;
@@ -348,7 +340,8 @@ use foo::Trait;
 fn test() {
     let msg = foo::Message(foo::MessageRef);
     let r = msg.deref();
-    r<|>;
+    r;
+  //^ &MessageRef
 }
 
 //- /lib.rs crate:foo
@@ -375,7 +368,6 @@ macro_rules! expand {
 expand!();
 "#,
     );
-    assert_eq!("&MessageRef", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -397,12 +389,12 @@ fn main() {
 }
 "#),
         @r###"
-        159..164 '{ 0 }': u64
-        161..162 '0': u64
-        175..197 '{     ...f(); }': ()
-        185..187 '_a': u64
-        191..192 'f': fn f() -> u64
-        191..194 'f()': u64
+    158..163 '{ 0 }': u64
+    160..161 '0': u64
+    174..196 '{     ...f(); }': ()
+    184..186 '_a': u64
+    190..191 'f': fn f() -> u64
+    190..193 'f()': u64
     "###
     );
 }
@@ -419,23 +411,23 @@ fn main() {
 }
 "#),
         @r###"
-        !0..6 '1usize': usize
-        11..90 '{     ...!(); }': ()
-        17..66 'macro_...     }': {unknown}
-        75..77 '_a': usize
+    !0..6 '1usize': usize
+    10..89 '{     ...!(); }': ()
+    16..65 'macro_...     }': {unknown}
+    74..76 '_a': usize
     "###
     );
 }
 
 #[test]
 fn infer_local_inner_macros() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:foo
 fn test() {
     let x = foo::foo!(1);
-    x<|>;
-}
+    x;
+} //^ i32
 
 //- /lib.rs crate:foo
 #[macro_export(local_inner_macros)]
@@ -450,7 +442,6 @@ macro_rules! bar {
 
 "#,
     );
-    assert_eq!("i32", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -466,8 +457,8 @@ fn main() {
 "#),
         @r###"
     !0..1 '0': i32
-    64..88 '{     ...!(); }': ()
-    74..75 'x': i32
+    63..87 '{     ...!(); }': ()
+    73..74 'x': i32
     "###
     );
 }
@@ -485,8 +476,8 @@ fn main() {
 "#),
         @r###"
     !0..2 '""': &str
-    64..88 '{     ...!(); }': ()
-    74..75 'x': &str
+    63..87 '{     ...!(); }': ()
+    73..74 'x': &str
     "###
     );
 }
@@ -504,8 +495,8 @@ fn main() {
 "#),
         @r###"
     !0..1 '0': i32
-    66..92 '{     ...!(); }': ()
-    76..77 'x': i32
+    65..91 '{     ...!(); }': ()
+    75..76 'x': i32
     "###
     );
 }
@@ -523,15 +514,15 @@ fn main() {
 "#),
         @r###"
     !0..13 '"helloworld!"': &str
-    66..122 '{     ...")); }': ()
-    76..77 'x': &str
+    65..121 '{     ...")); }': ()
+    75..76 'x': &str
     "###
     );
 }
 
 #[test]
 fn infer_builtin_macros_include() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs
 #[rustc_builtin_macro]
@@ -540,14 +531,13 @@ macro_rules! include {() => {}}
 include!("foo.rs");
 
 fn main() {
-    bar()<|>;
-}
+    bar();
+}     //^ u32
 
 //- /foo.rs
 fn bar() -> u32 {0}
 "#,
     );
-    assert_eq!("u32", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -565,18 +555,17 @@ macro_rules! include {() => {}}
 include!("foo.rs");
 
 fn main() {
-    RegisterBlock { }<|>;
+    RegisterBlock { };
+                  //^ RegisterBlock
 }
     "#;
     let fixture = format!("{}\n//- /foo.rs\n{}", fixture, big_file);
-
-    let (db, pos) = TestDB::with_position(&fixture);
-    assert_eq!("RegisterBlock", type_at_pos(&db, pos));
+    check_types(&fixture);
 }
 
 #[test]
 fn infer_builtin_macros_include_concat() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs
 #[rustc_builtin_macro]
@@ -588,19 +577,18 @@ macro_rules! concat {() => {}}
 include!(concat!("f", "oo.rs"));
 
 fn main() {
-    bar()<|>;
-}
+    bar();
+}     //^ u32
 
 //- /foo.rs
 fn bar() -> u32 {0}
 "#,
     );
-    assert_eq!("u32", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_builtin_macros_include_concat_with_bad_env_should_failed() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs
 #[rustc_builtin_macro]
@@ -615,32 +603,29 @@ macro_rules! env {() => {}}
 include!(concat!(env!("OUT_DIR"), "/foo.rs"));
 
 fn main() {
-    bar()<|>;
-}
+    bar();
+}     //^ {unknown}
 
 //- /foo.rs
 fn bar() -> u32 {0}
 "#,
     );
-    assert_eq!("{unknown}", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_builtin_macros_include_itself_should_failed() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs
 #[rustc_builtin_macro]
 macro_rules! include {() => {}}
 
 include!("main.rs");
 
 fn main() {
-    0<|>
-}
+    0
+} //^ i32
 "#,
     );
-    assert_eq!("i32", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -658,8 +643,8 @@ fn main() {
 "#),
         @r###"
     !0..13 '"helloworld!"': &str
-    104..161 '{     ...")); }': ()
-    114..115 'x': &str
+    103..160 '{     ...")); }': ()
+    113..114 'x': &str
     "###
     );
 }
@@ -677,23 +662,23 @@ fn main() {
 }
 "#),
         @r###"
-    !0..5 '"bar"': &str
-    88..116 '{     ...o"); }': ()
-    98..99 'x': &str
+    !0..22 '"__RA_...TED__"': &str
+    62..90 '{     ...o"); }': ()
+    72..73 'x': &str
     "###
     );
 }
 
 #[test]
 fn infer_derive_clone_simple() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:core
 #[derive(Clone)]
 struct S;
 fn test() {
-    S.clone()<|>;
-}
+    S.clone();
+}         //^ S
 
 //- /lib.rs crate:core
 #[prelude_import]
@@ -705,12 +690,11 @@ mod clone {
 }
 "#,
     );
-    assert_eq!("S", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_derive_clone_in_core() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /lib.rs crate:core
 #[prelude_import]
@@ -726,16 +710,15 @@ pub struct S;
 //- /main.rs crate:main deps:core
 use core::S;
 fn test() {
-    S.clone()<|>;
-}
+    S.clone();
+}         //^ S
 "#,
     );
-    assert_eq!("S", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_derive_clone_with_params() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:core
 #[derive(Clone)]
@@ -744,7 +727,8 @@ struct S;
 struct Wrapper<T>(T);
 struct NonClone;
 fn test() {
-    (Wrapper(S).clone(), Wrapper(NonClone).clone())<|>;
+    (Wrapper(S).clone(), Wrapper(NonClone).clone());
+  //^ (Wrapper<S>, {unknown})
 }
 
 //- /lib.rs crate:core
@@ -757,13 +741,12 @@ mod clone {
 }
 "#,
     );
-    assert_eq!("(Wrapper<S>, {unknown})", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_custom_derive_simple() {
     // FIXME: this test current now do nothing
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main
 use foo::Foo;
@@ -772,11 +755,10 @@ use foo::Foo;
 struct S{}
 
 fn test() {
-    S{}<|>;
-}
+    S{};
+}   //^ S
 "#,
     );
-    assert_eq!("S", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -794,12 +776,12 @@ fn main() {
 }
 "#),
         @r###"
-    52..111 '{     ...  }; }': ()
-    62..63 'x': u32
-    66..108 'match ...     }': u32
-    72..74 '()': ()
-    85..92 'unit!()': ()
-    96..101 '92u32': u32
+    51..110 '{     ...  }; }': ()
+    61..62 'x': u32
+    65..107 'match ...     }': u32
+    71..73 '()': ()
+    84..91 'unit!()': ()
+    95..100 '92u32': u32
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
index 558a70022..9c8f22314 100644
--- a/crates/ra_hir_ty/src/tests/method_resolution.rs
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -1,7 +1,6 @@
-use super::{infer, type_at, type_at_pos};
-use crate::test_db::TestDB;
 use insta::assert_snapshot;
-use ra_db::fixture::WithFixture;
+
+use super::{check_types, infer};
 
 #[test]
 fn infer_slice_method() {
@@ -22,15 +21,15 @@ fn test(x: &[u8]) {
 }
 "#),
         @r###"
-    45..49 'self': &[T]
-    56..79 '{     ...     }': T
-    66..73 'loop {}': !
-    71..73 '{}': ()
-    131..132 'x': &[u8]
-    141..163 '{     ...(x); }': ()
-    147..157 '<[_]>::foo': fn foo<u8>(&[u8]) -> u8
-    147..160 '<[_]>::foo(x)': u8
-    158..159 'x': &[u8]
+    44..48 'self': &[T]
+    55..78 '{     ...     }': T
+    65..72 'loop {}': !
+    70..72 '{}': ()
+    130..131 'x': &[u8]
+    140..162 '{     ...(x); }': ()
+    146..156 '<[_]>::foo': fn foo<u8>(&[u8]) -> u8
+    146..159 '<[_]>::foo(x)': u8
+    157..158 'x': &[u8]
     "###
     );
 }
@@ -52,15 +51,15 @@ fn test() {
 }
 "#),
         @r###"
-    49..75 '{     ...     }': A
-    59..69 'A { x: 0 }': A
-    66..67 '0': u32
-    88..122 '{     ...a.x; }': ()
-    98..99 'a': A
-    102..108 'A::new': fn new() -> A
-    102..110 'A::new()': A
-    116..117 'a': A
-    116..119 'a.x': u32
+    48..74 '{     ...     }': A
+    58..68 'A { x: 0 }': A
+    65..66 '0': u32
+    87..121 '{     ...a.x; }': ()
+    97..98 'a': A
+    101..107 'A::new': fn new() -> A
+    101..109 'A::new()': A
+    115..116 'a': A
+    115..118 'a.x': u32
     "###
     );
 }
@@ -87,19 +86,19 @@ fn test() {
 }
 "#),
         @r###"
-    47..67 '{     ...     }': A
-    57..61 'A::B': A
-    88..108 '{     ...     }': A
-    98..102 'A::C': A
-    121..178 '{     ...  c; }': ()
-    131..132 'a': A
-    135..139 'A::b': fn b() -> A
-    135..141 'A::b()': A
-    147..148 'a': A
-    158..159 'c': A
-    162..166 'A::c': fn c() -> A
-    162..168 'A::c()': A
-    174..175 'c': A
+    46..66 '{     ...     }': A
+    56..60 'A::B': A
+    87..107 '{     ...     }': A
+    97..101 'A::C': A
+    120..177 '{     ...  c; }': ()
+    130..131 'a': A
+    134..138 'A::b': fn b() -> A
+    134..140 'A::b()': A
+    146..147 'a': A
+    157..158 'c': A
+    161..165 'A::c': fn c() -> A
+    161..167 'A::c()': A
+    173..174 'c': A
     "###
     );
 }
@@ -131,22 +130,22 @@ fn test() {
 }
 "#),
         @r###"
-    56..64 '{ A {} }': A
-    58..62 'A {}': A
-    126..132 '{ 99 }': u32
-    128..130 '99': u32
-    202..210 '{ C {} }': C
-    204..208 'C {}': C
-    241..325 '{     ...g(); }': ()
-    251..252 'x': A
-    255..266 'a::A::thing': fn thing() -> A
-    255..268 'a::A::thing()': A
-    278..279 'y': u32
-    282..293 'b::B::thing': fn thing() -> u32
-    282..295 'b::B::thing()': u32
-    305..306 'z': C
-    309..320 'c::C::thing': fn thing() -> C
-    309..322 'c::C::thing()': C
+    55..63 '{ A {} }': A
+    57..61 'A {}': A
+    125..131 '{ 99 }': u32
+    127..129 '99': u32
+    201..209 '{ C {} }': C
+    203..207 'C {}': C
+    240..324 '{     ...g(); }': ()
+    250..251 'x': A
+    254..265 'a::A::thing': fn thing() -> A
+    254..267 'a::A::thing()': A
+    277..278 'y': u32
+    281..292 'b::B::thing': fn thing() -> u32
+    281..294 'b::B::thing()': u32
+    304..305 'z': C
+    308..319 'c::C::thing': fn thing() -> C
+    308..321 'c::C::thing()': C
     "###
     );
 }
@@ -170,74 +169,20 @@ fn test() {
 }
 "#),
         @r###"
-    64..67 'val': T
-    82..109 '{     ...     }': Gen<T>
-    92..103 'Gen { val }': Gen<T>
-    98..101 'val': T
-    123..155 '{     ...32); }': ()
-    133..134 'a': Gen<u32>
-    137..146 'Gen::make': fn make<u32>(u32) -> Gen<u32>
-    137..152 'Gen::make(0u32)': Gen<u32>
-    147..151 '0u32': u32
+    63..66 'val': T
+    81..108 '{     ...     }': Gen<T>
+    91..102 'Gen { val }': Gen<T>
+    97..100 'val': T
+    122..154 '{     ...32); }': ()
+    132..133 'a': Gen<u32>
+    136..145 'Gen::make': fn make<u32>(u32) -> Gen<u32>
+    136..151 'Gen::make(0u32)': Gen<u32>
+    146..150 '0u32': u32
     "###
     );
 }
 
 #[test]
-fn infer_associated_method_generics_with_default_param() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T=u32> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-}
-"#),
-        @r###"
-    80..104 '{     ...     }': Gen<T>
-    90..98 'loop { }': !
-    95..98 '{ }': ()
-    118..146 '{     ...e(); }': ()
-    128..129 'a': Gen<u32>
-    132..141 'Gen::make': fn make<u32>() -> Gen<u32>
-    132..143 'Gen::make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_tuple_param() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct Gen<T=()> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-    a.val<|>;
-}
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
 fn infer_associated_method_generics_without_args() {
     assert_snapshot!(
         infer(r#"
@@ -256,13 +201,13 @@ fn test() {
 }
 "#),
         @r###"
-    76..100 '{     ...     }': Gen<T>
-    86..94 'loop { }': !
-    91..94 '{ }': ()
-    114..149 '{     ...e(); }': ()
-    124..125 'a': Gen<u32>
-    128..144 'Gen::<...::make': fn make<u32>() -> Gen<u32>
-    128..146 'Gen::<...make()': Gen<u32>
+    75..99 '{     ...     }': Gen<T>
+    85..93 'loop { }': !
+    90..93 '{ }': ()
+    113..148 '{     ...e(); }': ()
+    123..124 'a': Gen<u32>
+    127..143 'Gen::<...::make': fn make<u32>() -> Gen<u32>
+    127..145 'Gen::<...make()': Gen<u32>
     "###
     );
 }
@@ -287,26 +232,26 @@ fn test() {
 }
 "#),
         @r###"
-    102..126 '{     ...     }': Gen<u32, T>
-    112..120 'loop { }': !
-    117..120 '{ }': ()
-    140..180 '{     ...e(); }': ()
-    150..151 'a': Gen<u32, u64>
-    154..175 'Gen::<...::make': fn make<u64>() -> Gen<u32, u64>
-    154..177 'Gen::<...make()': Gen<u32, u64>
+    101..125 '{     ...     }': Gen<u32, T>
+    111..119 'loop { }': !
+    116..119 '{ }': ()
+    139..179 '{     ...e(); }': ()
+    149..150 'a': Gen<u32, u64>
+    153..174 'Gen::<...::make': fn make<u64>() -> Gen<u32, u64>
+    153..176 'Gen::<...make()': Gen<u32, u64>
     "###
     );
 }
 
 #[test]
 fn cross_crate_associated_method_call() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:other_crate
 fn test() {
     let x = other_crate::foo::S::thing();
-    x<|>;
-}
+    x;
+} //^ i128
 
 //- /lib.rs crate:other_crate
 mod foo {
@@ -317,7 +262,6 @@ mod foo {
 }
 "#,
     );
-    assert_eq!("i128", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -341,13 +285,13 @@ fn test() {
 }
 "#),
         @r###"
-    31..35 'self': &Self
-    110..114 'self': &Self
-    170..228 '{     ...i128 }': ()
-    176..178 'S1': S1
-    176..187 'S1.method()': u32
-    203..205 'S2': S2
-    203..214 'S2.method()': i128
+    30..34 'self': &Self
+    109..113 'self': &Self
+    169..227 '{     ...i128 }': ()
+    175..177 'S1': S1
+    175..186 'S1.method()': u32
+    202..204 'S2': S2
+    202..213 'S2.method()': i128
     "###
     );
 }
@@ -388,14 +332,14 @@ mod bar_test {
 }
 "#),
         @r###"
-    63..67 'self': &Self
-    169..173 'self': &Self
-    300..337 '{     ...     }': ()
-    310..311 'S': S
-    310..320 'S.method()': u32
-    416..454 '{     ...     }': ()
-    426..427 'S': S
-    426..436 'S.method()': i128
+    62..66 'self': &Self
+    168..172 'self': &Self
+    299..336 '{     ...     }': ()
+    309..310 'S': S
+    309..319 'S.method()': u32
+    415..453 '{     ...     }': ()
+    425..426 'S': S
+    425..435 'S.method()': i128
     "###
     );
 }
@@ -415,10 +359,10 @@ fn test() {
 }
 "#),
         @r###"
-    33..37 'self': &Self
-    92..111 '{     ...d(); }': ()
-    98..99 'S': S
-    98..108 'S.method()': u32
+    32..36 'self': &Self
+    91..110 '{     ...d(); }': ()
+    97..98 'S': S
+    97..107 'S.method()': u32
     "###
     );
 }
@@ -444,17 +388,17 @@ fn test() {
 }
 "#),
         @r###"
-    43..47 'self': &Self
-    82..86 'self': &Self
-    210..361 '{     ..., i8 }': ()
-    216..218 'S1': S1
-    216..228 'S1.method1()': (u8, u16, u32)
-    250..252 'S1': S1
-    250..262 'S1.method2()': (u32, u16, u8)
-    284..286 'S2': S2
-    284..296 'S2.method1()': (i8, i16, {unknown})
-    324..326 'S2': S2
-    324..336 'S2.method2()': ({unknown}, i16, i8)
+    42..46 'self': &Self
+    81..85 'self': &Self
+    209..360 '{     ..., i8 }': ()
+    215..217 'S1': S1
+    215..227 'S1.method1()': (u8, u16, u32)
+    249..251 'S1': S1
+    249..261 'S1.method2()': (u32, u16, u8)
+    283..285 'S2': S2
+    283..295 'S2.method1()': (i8, i16, {unknown})
+    323..325 'S2': S2
+    323..335 'S2.method2()': ({unknown}, i16, i8)
     "###
     );
 }
@@ -474,12 +418,12 @@ fn test() {
 }
 "#),
         @r###"
-    33..37 'self': &Self
-    102..127 '{     ...d(); }': ()
-    108..109 'S': S<u32>(u32) -> S<u32>
-    108..115 'S(1u32)': S<u32>
-    108..124 'S(1u32...thod()': u32
-    110..114 '1u32': u32
+    32..36 'self': &Self
+    101..126 '{     ...d(); }': ()
+    107..108 'S': S<u32>(u32) -> S<u32>
+    107..114 'S(1u32)': S<u32>
+    107..123 'S(1u32...thod()': u32
+    109..113 '1u32': u32
     "###
     );
 }
@@ -500,16 +444,16 @@ fn test() {
 }
 "#),
         @r###"
-    87..193 '{     ...t(); }': ()
-    97..99 's1': S
-    105..121 'Defaul...efault': fn default<S>() -> S
-    105..123 'Defaul...ault()': S
-    133..135 's2': S
-    138..148 'S::default': fn default<S>() -> S
-    138..150 'S::default()': S
-    160..162 's3': S
-    165..188 '<S as ...efault': fn default<S>() -> S
-    165..190 '<S as ...ault()': S
+    86..192 '{     ...t(); }': ()
+    96..98 's1': S
+    104..120 'Defaul...efault': fn default<S>() -> S
+    104..122 'Defaul...ault()': S
+    132..134 's2': S
+    137..147 'S::default': fn default<S>() -> S
+    137..149 'S::default()': S
+    159..161 's3': S
+    164..187 '<S as ...efault': fn default<S>() -> S
+    164..189 '<S as ...ault()': S
     "###
     );
 }
@@ -532,16 +476,16 @@ fn test() {
 }
 "#),
         @r###"
-    127..211 '{     ...e(); }': ()
-    137..138 'a': u32
-    141..148 'S::make': fn make<S, u32>() -> u32
-    141..150 'S::make()': u32
-    160..161 'b': u64
-    164..178 'G::<u64>::make': fn make<G<u64>, u64>() -> u64
-    164..180 'G::<u6...make()': u64
-    190..191 'c': f64
-    199..206 'G::make': fn make<G<f64>, f64>() -> f64
-    199..208 'G::make()': f64
+    126..210 '{     ...e(); }': ()
+    136..137 'a': u32
+    140..147 'S::make': fn make<S, u32>() -> u32
+    140..149 'S::make()': u32
+    159..160 'b': u64
+    163..177 'G::<u64>::make': fn make<G<u64>, u64>() -> u64
+    163..179 'G::<u6...make()': u64
+    189..190 'c': f64
+    198..205 'G::make': fn make<G<f64>, f64>() -> f64
+    198..207 'G::make()': f64
     "###
     );
 }
@@ -566,22 +510,22 @@ fn test() {
 }
 "#),
         @r###"
-    135..313 '{     ...e(); }': ()
-    145..146 'a': (u32, i64)
-    149..163 'S::make::<i64>': fn make<S, u32, i64>() -> (u32, i64)
-    149..165 'S::mak...i64>()': (u32, i64)
-    175..176 'b': (u32, i64)
-    189..196 'S::make': fn make<S, u32, i64>() -> (u32, i64)
-    189..198 'S::make()': (u32, i64)
-    208..209 'c': (u32, i64)
-    212..233 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (u32, i64)
-    212..235 'G::<u3...i64>()': (u32, i64)
-    245..246 'd': (u32, i64)
-    259..273 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (u32, i64)
-    259..275 'G::mak...i64>()': (u32, i64)
-    285..286 'e': (u32, i64)
-    301..308 'G::make': fn make<G<u32>, u32, i64>() -> (u32, i64)
-    301..310 'G::make()': (u32, i64)
+    134..312 '{     ...e(); }': ()
+    144..145 'a': (u32, i64)
+    148..162 'S::make::<i64>': fn make<S, u32, i64>() -> (u32, i64)
+    148..164 'S::mak...i64>()': (u32, i64)
+    174..175 'b': (u32, i64)
+    188..195 'S::make': fn make<S, u32, i64>() -> (u32, i64)
+    188..197 'S::make()': (u32, i64)
+    207..208 'c': (u32, i64)
+    211..232 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (u32, i64)
+    211..234 'G::<u3...i64>()': (u32, i64)
+    244..245 'd': (u32, i64)
+    258..272 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (u32, i64)
+    258..274 'G::mak...i64>()': (u32, i64)
+    284..285 'e': (u32, i64)
+    300..307 'G::make': fn make<G<u32>, u32, i64>() -> (u32, i64)
+    300..309 'G::make()': (u32, i64)
     "###
     );
 }
@@ -600,10 +544,10 @@ fn test() {
 }
 "#),
         @r###"
-    101..127 '{     ...e(); }': ()
-    111..112 'a': (S<i32>, i64)
-    115..122 'S::make': fn make<S<i32>, i64>() -> (S<i32>, i64)
-    115..124 'S::make()': (S<i32>, i64)
+    100..126 '{     ...e(); }': ()
+    110..111 'a': (S<i32>, i64)
+    114..121 'S::make': fn make<S<i32>, i64>() -> (S<i32>, i64)
+    114..123 'S::make()': (S<i32>, i64)
     "###
     );
 }
@@ -624,13 +568,13 @@ fn test() {
 }
 "#),
         @r###"
-    131..203 '{     ...e(); }': ()
-    141..142 'a': (S<u64>, i64)
-    158..165 'S::make': fn make<S<u64>, i64>() -> (S<u64>, i64)
-    158..167 'S::make()': (S<u64>, i64)
-    177..178 'b': (S<u32>, i32)
-    191..198 'S::make': fn make<S<u32>, i32>() -> (S<u32>, i32)
-    191..200 'S::make()': (S<u32>, i32)
+    130..202 '{     ...e(); }': ()
+    140..141 'a': (S<u64>, i64)
+    157..164 'S::make': fn make<S<u64>, i64>() -> (S<u64>, i64)
+    157..166 'S::make()': (S<u64>, i64)
+    176..177 'b': (S<u32>, i32)
+    190..197 'S::make': fn make<S<u32>, i32>() -> (S<u32>, i32)
+    190..199 'S::make()': (S<u32>, i32)
     "###
     );
 }
@@ -650,13 +594,13 @@ fn test() {
 }
 "#),
         @r###"
-    107..211 '{     ...>(); }': ()
-    117..118 'a': (S<u64>, i64, u8)
-    121..150 '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (S<u64>, i64, u8)
-    121..152 '<S as ...<u8>()': (S<u64>, i64, u8)
-    162..163 'b': (S<u64>, i64, u8)
-    182..206 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (S<u64>, i64, u8)
-    182..208 'Trait:...<u8>()': (S<u64>, i64, u8)
+    106..210 '{     ...>(); }': ()
+    116..117 'a': (S<u64>, i64, u8)
+    120..149 '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (S<u64>, i64, u8)
+    120..151 '<S as ...<u8>()': (S<u64>, i64, u8)
+    161..162 'b': (S<u64>, i64, u8)
+    181..205 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (S<u64>, i64, u8)
+    181..207 'Trait:...<u8>()': (S<u64>, i64, u8)
     "###
     );
 }
@@ -673,11 +617,11 @@ fn test<T: Trait>(t: T) {
 }
 "#),
         @r###"
-    30..34 'self': &Self
-    64..65 't': T
-    70..89 '{     ...d(); }': ()
-    76..77 't': T
-    76..86 't.method()': u32
+    29..33 'self': &Self
+    63..64 't': T
+    69..88 '{     ...d(); }': ()
+    75..76 't': T
+    75..85 't.method()': u32
     "###
     );
 }
@@ -694,11 +638,11 @@ fn test<U, T: Trait<U>>(t: T) {
 }
 "#),
         @r###"
-    33..37 'self': &Self
-    71..72 't': T
-    77..96 '{     ...d(); }': ()
-    83..84 't': T
-    83..93 't.method()': U
+    32..36 'self': &Self
+    70..71 't': T
+    76..95 '{     ...d(); }': ()
+    82..83 't': T
+    82..92 't.method()': U
     "###
     );
 }
@@ -720,153 +664,145 @@ fn test() {
 }
 "#),
         @r###"
-    29..33 'self': Self
-    111..202 '{     ...(S); }': ()
-    121..122 'x': u32
-    130..131 'S': S
-    130..138 'S.into()': u32
-    148..149 'y': u64
-    157..158 'S': S
-    157..165 'S.into()': u64
-    175..176 'z': u64
-    179..196 'Into::...::into': fn into<S, u64>(S) -> u64
-    179..199 'Into::...nto(S)': u64
-    197..198 'S': S
+    28..32 'self': Self
+    110..201 '{     ...(S); }': ()
+    120..121 'x': u32
+    129..130 'S': S
+    129..137 'S.into()': u32
+    147..148 'y': u64
+    156..157 'S': S
+    156..164 'S.into()': u64
+    174..175 'z': u64
+    178..195 'Into::...::into': fn into<S, u64>(S) -> u64
+    178..198 'Into::...nto(S)': u64
+    196..197 'S': S
     "###
     );
 }
 
 #[test]
 fn method_resolution_unify_impl_self_type() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct S<T>;
 impl S<u32> { fn foo(&self) -> u8 {} }
 impl S<i32> { fn foo(&self) -> i8 {} }
-fn test() { (S::<u32>.foo(), S::<i32>.foo())<|>; }
+fn test() { (S::<u32>.foo(), S::<i32>.foo()); }
+          //^ (u8, i8)
 "#,
     );
-    assert_eq!(t, "(u8, i8)");
 }
 
 #[test]
 fn method_resolution_trait_before_autoref() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl S { fn foo(&self) -> i8 { 0 } }
 impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn method_resolution_by_value_before_autoref() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Clone { fn clone(&self) -> Self; }
 struct S;
 impl Clone for S {}
 impl Clone for &S {}
-fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
+fn test() { (S.clone(), (&S).clone(), (&&S).clone()); }
+          //^ (S, S, &S)
 "#,
     );
-    assert_eq!(t, "(S, S, &S)");
 }
 
 #[test]
 fn method_resolution_trait_before_autoderef() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl S { fn foo(self) -> i8 { 0 } }
 impl Trait for &S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
+fn test() { (&S).foo(); }
+                   //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn method_resolution_impl_before_trait() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl S { fn foo(self) -> i8 { 0 } }
 impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ i8
 "#,
     );
-    assert_eq!(t, "i8");
 }
 
 #[test]
 fn method_resolution_impl_ref_before_trait() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl S { fn foo(&self) -> i8 { 0 } }
 impl Trait for &S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ i8
 "#,
     );
-    assert_eq!(t, "i8");
 }
 
 #[test]
 fn method_resolution_trait_autoderef() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
+fn test() { (&S).foo(); }
+                   //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn method_resolution_unsize_array() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 #[lang = "slice"]
 impl<T> [T] {
     fn len(&self) -> usize { loop {} }
 }
 fn test() {
     let a = [1, 2, 3];
-    a.len()<|>;
-}
+    a.len();
+}       //^ usize
 "#,
     );
-    assert_eq!(t, "usize");
 }
 
 #[test]
 fn method_resolution_trait_from_prelude() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:other_crate
 struct S;
 impl Clone for S {}
 
 fn test() {
-    S.clone()<|>;
+    S.clone();
+          //^ S
 }
 
 //- /lib.rs crate:other_crate
@@ -879,115 +815,107 @@ mod foo {
 }
 "#,
     );
-    assert_eq!("S", type_at_pos(&db, pos));
 }
 
 #[test]
 fn method_resolution_where_clause_for_unknown_trait() {
     // The blanket impl currently applies because we ignore the unresolved where clause
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl<T> Trait for T where T: UnknownTrait {}
-fn test() { (&S).foo()<|>; }
+fn test() { (&S).foo(); }
+                   //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn method_resolution_where_clause_not_met() {
     // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
+    // This is also to make sure that we don't resolve to the foo method just
+    // because that's the only method named foo we can find, which would make
+    // the below tests not work
+    check_types(
         r#"
-//- /main.rs
 trait Clone {}
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl<T> Trait for T where T: Clone {}
-fn test() { (&S).foo()<|>; }
+fn test() { (&S).foo(); }
+                   //^ {unknown}
 "#,
     );
-    // This is also to make sure that we don't resolve to the foo method just
-    // because that's the only method named foo we can find, which would make
-    // the below tests not work
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn method_resolution_where_clause_inline_not_met() {
     // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Clone {}
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl<T: Clone> Trait for T {}
-fn test() { (&S).foo()<|>; }
+fn test() { (&S).foo(); }
+                   //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn method_resolution_where_clause_1() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Clone {}
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Clone for S {}
 impl<T> Trait for T where T: Clone {}
-fn test() { S.foo()<|>; }
+fn test() { S.foo(); }
+                //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn method_resolution_where_clause_2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Into<T> { fn into(self) -> T; }
 trait From<T> { fn from(other: T) -> Self; }
 struct S1;
 struct S2;
 impl From<S2> for S1 {}
 impl<T, U> Into<U> for T where U: From<T> {}
-fn test() { S2.into()<|>; }
+fn test() { S2.into(); }
+                  //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn method_resolution_where_clause_inline() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Into<T> { fn into(self) -> T; }
 trait From<T> { fn from(other: T) -> Self; }
 struct S1;
 struct S2;
 impl From<S2> for S1 {}
 impl<T, U: From<T>> Into<U> for T {}
-fn test() { S2.into()<|>; }
+fn test() { S2.into(); }
+                  //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn method_resolution_overloaded_method() {
     test_utils::mark::check!(impl_self_type_match_without_receiver);
-    let t = type_at(
+    check_types(
         r#"
-//- main.rs
 struct Wrapper<T>(T);
 struct Foo<T>(T);
 struct Bar<T>(T);
@@ -1007,30 +935,30 @@ impl<T> Wrapper<Bar<T>> {
 fn main() {
     let a = Wrapper::<Foo<f32>>::new(1.0);
     let b = Wrapper::<Bar<f32>>::new(1.0);
-    (a, b)<|>;
+    (a, b);
+  //^ (Wrapper<Foo<f32>>, Wrapper<Bar<f32>>)
 }
 "#,
     );
-    assert_eq!(t, "(Wrapper<Foo<f32>>, Wrapper<Bar<f32>>)")
 }
 
 #[test]
 fn method_resolution_encountering_fn_type() {
-    type_at(
+    check_types(
         r#"
 //- /main.rs
 fn foo() {}
 trait FnOnce { fn call(self); }
-fn test() { foo.call()<|>; }
+fn test() { foo.call(); }
+                   //^ {unknown}
 "#,
     );
 }
 
 #[test]
 fn method_resolution_non_parameter_type() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 mod a {
     pub trait Foo {
         fn foo(&self);
@@ -1042,18 +970,16 @@ fn foo<T>(t: Wrapper<T>)
 where
     Wrapper<T>: a::Foo,
 {
-    t.foo()<|>;
-}
+    t.foo();
+}       //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn method_resolution_3373() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct A<T>(T);
 
 impl A<i32> {
@@ -1061,19 +987,17 @@ impl A<i32> {
 }
 
 fn main() {
-    A::from(3)<|>;
-}
+    A::from(3);
+}          //^ A<i32>
 "#,
     );
-    assert_eq!(t, "A<i32>");
 }
 
 #[test]
 fn method_resolution_slow() {
     // this can get quite slow if we set the solver size limit too high
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait SendX {}
 
 struct S1; impl SendX for S1 {}
@@ -1091,10 +1015,10 @@ trait FnX {}
 
 impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
 
-fn test() { (S {}).method()<|>; }
+fn test() { (S {}).method(); }
+                        //^ ()
 "#,
     );
-    assert_eq!(t, "()");
 }
 
 #[test]
@@ -1117,13 +1041,13 @@ fn test(d: &dyn Trait) {
 }
 "#),
         @r###"
-    52..56 'self': &Self
-    65..70 '{ 0 }': u32
-    67..68 '0': u32
-    177..178 'd': &dyn Trait
-    192..208 '{     ...o(); }': ()
-    198..199 'd': &dyn Trait
-    198..205 'd.foo()': u32
+    51..55 'self': &Self
+    64..69 '{ 0 }': u32
+    66..67 '0': u32
+    176..177 'd': &dyn Trait
+    191..207 '{     ...o(); }': ()
+    197..198 'd': &dyn Trait
+    197..204 'd.foo()': u32
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/never_type.rs b/crates/ra_hir_ty/src/tests/never_type.rs
index 082c47208..64d421d40 100644
--- a/crates/ra_hir_ty/src/tests/never_type.rs
+++ b/crates/ra_hir_ty/src/tests/never_type.rs
@@ -1,99 +1,91 @@
 use insta::assert_snapshot;
 
-use super::{infer_with_mismatches, type_at};
+use super::{check_types, infer_with_mismatches};
 
 #[test]
 fn infer_never1() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test() {
     let t = return;
-    t<|>;
-}
+    t;
+} //^ !
 "#,
     );
-    assert_eq!(t, "!");
 }
 
 #[test]
 fn infer_never2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn gen<T>() -> T { loop {} }
 
 fn test() {
     let a = gen();
     if false { a } else { loop {} };
-    a<|>;
-}
+    a;
+} //^ !
 "#,
     );
-    assert_eq!(t, "!");
 }
 
 #[test]
 fn infer_never3() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn gen<T>() -> T { loop {} }
 
 fn test() {
     let a = gen();
     if false { loop {} } else { a };
-    a<|>;
+    a;
+  //^ !
 }
 "#,
     );
-    assert_eq!(t, "!");
 }
 
 #[test]
 fn never_type_in_generic_args() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 enum Option<T> { None, Some(T) }
 
 fn test() {
     let a = if true { Option::None } else { Option::Some(return) };
-    a<|>;
-}
+    a;
+} //^ Option<!>
 "#,
     );
-    assert_eq!(t, "Option<!>");
 }
 
 #[test]
 fn never_type_can_be_reinferred1() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn gen<T>() -> T { loop {} }
 
 fn test() {
     let a = gen();
     if false { loop {} } else { a };
-    a<|>;
+    a;
+  //^ ()
     if false { a };
 }
 "#,
     );
-    assert_eq!(t, "()");
 }
 
 #[test]
 fn never_type_can_be_reinferred2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 enum Option<T> { None, Some(T) }
 
 fn test() {
     let a = if true { Option::None } else { Option::Some(return) };
-    a<|>;
+    a;
+  //^ Option<i32>
     match 42 {
         42 => a,
         _ => Option::Some(42),
@@ -101,19 +93,18 @@ fn test() {
 }
 "#,
     );
-    assert_eq!(t, "Option<i32>");
 }
 
 #[test]
 fn never_type_can_be_reinferred3() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 enum Option<T> { None, Some(T) }
 
 fn test() {
     let a = if true { Option::None } else { Option::Some(return) };
-    a<|>;
+    a;
+  //^ Option<&str>
     match 42 {
         42 => a,
         _ => Option::Some("str"),
@@ -121,82 +112,72 @@ fn test() {
 }
 "#,
     );
-    assert_eq!(t, "Option<&str>");
 }
 
 #[test]
 fn match_no_arm() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 enum Void {}
 
 fn test(a: Void) {
     let t = match a {};
-    t<|>;
-}
+    t;
+} //^ !
 "#,
     );
-    assert_eq!(t, "!");
 }
 
 #[test]
 fn match_unknown_arm() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(a: Option) {
     let t = match 0 {
         _ => unknown,
     };
-    t<|>;
-}
+    t;
+} //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn if_never() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test() {
     let i = if true {
         loop {}
     } else {
         3.0
     };
-    i<|>;
-}
+    i;
+} //^ f64
 "#,
     );
-    assert_eq!(t, "f64");
 }
 
 #[test]
 fn if_else_never() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(input: bool) {
     let i = if input {
         2.0
     } else {
         return
     };
-    i<|>;
-}
+    i;
+} //^ f64
 "#,
     );
-    assert_eq!(t, "f64");
 }
 
 #[test]
 fn match_first_arm_never() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(a: i32) {
     let i = match a {
         1 => return,
@@ -204,18 +185,16 @@ fn test(a: i32) {
         3 => loop {},
         _ => 3.0,
     };
-    i<|>;
-}
+    i;
+} //^ f64
 "#,
     );
-    assert_eq!(t, "f64");
 }
 
 #[test]
 fn match_second_arm_never() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(a: i32) {
     let i = match a {
         1 => 3.0,
@@ -223,45 +202,40 @@ fn test(a: i32) {
         3 => 3.0,
         _ => return,
     };
-    i<|>;
-}
+    i;
+} //^ f64
 "#,
     );
-    assert_eq!(t, "f64");
 }
 
 #[test]
 fn match_all_arms_never() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(a: i32) {
     let i = match a {
         2 => return,
         _ => loop {},
     };
-    i<|>;
-}
+    i;
+} //^ !
 "#,
     );
-    assert_eq!(t, "!");
 }
 
 #[test]
 fn match_no_never_arms() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 fn test(a: i32) {
     let i = match a {
         2 => 2.0,
         _ => 3.0,
     };
-    i<|>;
-}
+    i;
+} //^ f64
 "#,
     );
-    assert_eq!(t, "f64");
 }
 
 #[test]
@@ -291,40 +265,40 @@ fn test6() {
         true,
     );
     assert_snapshot!(t, @r###"
-    25..53 '{     ...urn; }': ()
-    35..36 'x': u32
-    44..50 'return': !
-    65..98 '{     ...; }; }': ()
-    75..76 'x': u32
-    84..95 '{ return; }': u32
-    86..92 'return': !
-    110..139 '{     ... {}; }': ()
-    120..121 'x': u32
-    129..136 'loop {}': !
-    134..136 '{}': ()
-    151..184 '{     ...} }; }': ()
-    161..162 'x': u32
-    170..181 '{ loop {} }': u32
-    172..179 'loop {}': !
-    177..179 '{}': ()
-    196..260 '{     ...} }; }': ()
-    206..207 'x': u32
-    215..257 '{ if t...}; } }': u32
-    217..255 'if tru... {}; }': u32
-    220..224 'true': bool
-    225..237 '{ loop {}; }': u32
-    227..234 'loop {}': !
-    232..234 '{}': ()
-    243..255 '{ loop {}; }': u32
-    245..252 'loop {}': !
-    250..252 '{}': ()
-    272..324 '{     ...; }; }': ()
-    282..283 'x': u32
-    291..321 '{ let ...; }; }': u32
-    297..298 'y': u32
-    306..318 '{ loop {}; }': u32
-    308..315 'loop {}': !
-    313..315 '{}': ()
+    11..39 '{     ...urn; }': ()
+    21..22 'x': u32
+    30..36 'return': !
+    51..84 '{     ...; }; }': ()
+    61..62 'x': u32
+    70..81 '{ return; }': u32
+    72..78 'return': !
+    96..125 '{     ... {}; }': ()
+    106..107 'x': u32
+    115..122 'loop {}': !
+    120..122 '{}': ()
+    137..170 '{     ...} }; }': ()
+    147..148 'x': u32
+    156..167 '{ loop {} }': u32
+    158..165 'loop {}': !
+    163..165 '{}': ()
+    182..246 '{     ...} }; }': ()
+    192..193 'x': u32
+    201..243 '{ if t...}; } }': u32
+    203..241 'if tru... {}; }': u32
+    206..210 'true': bool
+    211..223 '{ loop {}; }': u32
+    213..220 'loop {}': !
+    218..220 '{}': ()
+    229..241 '{ loop {}; }': u32
+    231..238 'loop {}': !
+    236..238 '{}': ()
+    258..310 '{     ...; }; }': ()
+    268..269 'x': u32
+    277..307 '{ let ...; }; }': u32
+    283..284 'y': u32
+    292..304 '{ loop {}; }': u32
+    294..301 'loop {}': !
+    299..301 '{}': ()
     "###);
 }
 
@@ -341,14 +315,14 @@ fn test1() {
         true,
     );
     assert_snapshot!(t, @r###"
-    25..98 '{     ..." }; }': ()
-    68..69 'x': u32
-    77..95 '{ loop...foo" }': &str
-    79..86 'loop {}': !
-    84..86 '{}': ()
-    88..93 '"foo"': &str
-    77..95: expected u32, got &str
-    88..93: expected u32, got &str
+    11..84 '{     ..." }; }': ()
+    54..55 'x': u32
+    63..81 '{ loop...foo" }': &str
+    65..72 'loop {}': !
+    70..72 '{}': ()
+    74..79 '"foo"': &str
+    63..81: expected u32, got &str
+    74..79: expected u32, got &str
     "###);
 }
 
@@ -381,58 +355,58 @@ fn test3() {
         true,
     );
     assert_snapshot!(t, @r###"
-    25..99 '{     ...} }; }': ()
-    68..69 'x': u32
-    77..96 '{ loop...k; } }': ()
-    79..94 'loop { break; }': ()
-    84..94 '{ break; }': ()
-    86..91 'break': !
-    77..96: expected u32, got ()
-    79..94: expected u32, got ()
-    111..357 '{     ...; }; }': ()
-    154..155 'x': u32
-    163..189 '{ for ...; }; }': ()
-    165..186 'for a ...eak; }': ()
-    169..170 'a': {unknown}
-    174..175 'b': {unknown}
-    176..186 '{ break; }': ()
-    178..183 'break': !
-    240..241 'x': u32
-    249..267 '{ for ... {}; }': ()
-    251..264 'for a in b {}': ()
-    255..256 'a': {unknown}
-    260..261 'b': {unknown}
-    262..264 '{}': ()
-    318..319 'x': u32
-    327..354 '{ for ...; }; }': ()
-    329..351 'for a ...urn; }': ()
-    333..334 'a': {unknown}
-    338..339 'b': {unknown}
-    340..351 '{ return; }': ()
-    342..348 'return': !
-    163..189: expected u32, got ()
-    249..267: expected u32, got ()
-    327..354: expected u32, got ()
-    369..668 '{     ...; }; }': ()
-    412..413 'x': u32
-    421..447 '{ whil...; }; }': ()
-    423..444 'while ...eak; }': ()
-    429..433 'true': bool
-    434..444 '{ break; }': ()
-    436..441 'break': !
-    551..552 'x': u32
-    560..578 '{ whil... {}; }': ()
-    562..575 'while true {}': ()
-    568..572 'true': bool
-    573..575 '{}': ()
-    629..630 'x': u32
-    638..665 '{ whil...; }; }': ()
-    640..662 'while ...urn; }': ()
-    646..650 'true': bool
-    651..662 '{ return; }': ()
-    653..659 'return': !
-    421..447: expected u32, got ()
-    560..578: expected u32, got ()
-    638..665: expected u32, got ()
+    11..85 '{     ...} }; }': ()
+    54..55 'x': u32
+    63..82 '{ loop...k; } }': ()
+    65..80 'loop { break; }': ()
+    70..80 '{ break; }': ()
+    72..77 'break': !
+    63..82: expected u32, got ()
+    65..80: expected u32, got ()
+    97..343 '{     ...; }; }': ()
+    140..141 'x': u32
+    149..175 '{ for ...; }; }': ()
+    151..172 'for a ...eak; }': ()
+    155..156 'a': {unknown}
+    160..161 'b': {unknown}
+    162..172 '{ break; }': ()
+    164..169 'break': !
+    226..227 'x': u32
+    235..253 '{ for ... {}; }': ()
+    237..250 'for a in b {}': ()
+    241..242 'a': {unknown}
+    246..247 'b': {unknown}
+    248..250 '{}': ()
+    304..305 'x': u32
+    313..340 '{ for ...; }; }': ()
+    315..337 'for a ...urn; }': ()
+    319..320 'a': {unknown}
+    324..325 'b': {unknown}
+    326..337 '{ return; }': ()
+    328..334 'return': !
+    149..175: expected u32, got ()
+    235..253: expected u32, got ()
+    313..340: expected u32, got ()
+    355..654 '{     ...; }; }': ()
+    398..399 'x': u32
+    407..433 '{ whil...; }; }': ()
+    409..430 'while ...eak; }': ()
+    415..419 'true': bool
+    420..430 '{ break; }': ()
+    422..427 'break': !
+    537..538 'x': u32
+    546..564 '{ whil... {}; }': ()
+    548..561 'while true {}': ()
+    554..558 'true': bool
+    559..561 '{}': ()
+    615..616 'x': u32
+    624..651 '{ whil...; }; }': ()
+    626..648 'while ...urn; }': ()
+    632..636 'true': bool
+    637..648 '{ return; }': ()
+    639..645 'return': !
+    407..433: expected u32, got ()
+    546..564: expected u32, got ()
+    624..651: expected u32, got ()
     "###);
 }
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
index fe62587c0..f937426bd 100644
--- a/crates/ra_hir_ty/src/tests/patterns.rs
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -30,54 +30,54 @@ fn test(x: &i32) {
 }
 "#),
         @r###"
-    9..10 'x': &i32
-    18..369 '{     ...o_x; }': ()
-    28..29 'y': &i32
-    32..33 'x': &i32
-    43..45 '&z': &i32
-    44..45 'z': i32
-    48..49 'x': &i32
-    59..60 'a': i32
-    63..64 'z': i32
-    74..80 '(c, d)': (i32, &str)
-    75..76 'c': i32
-    78..79 'd': &str
-    83..95 '(1, "hello")': (i32, &str)
-    84..85 '1': i32
-    87..94 '"hello"': &str
-    102..152 'for (e...     }': ()
-    106..112 '(e, f)': ({unknown}, {unknown})
-    107..108 'e': {unknown}
-    110..111 'f': {unknown}
-    116..125 'some_iter': {unknown}
-    126..152 '{     ...     }': ()
-    140..141 'g': {unknown}
-    144..145 'e': {unknown}
-    158..205 'if let...     }': ()
-    165..170 '[val]': [{unknown}]
-    166..169 'val': {unknown}
-    173..176 'opt': [{unknown}]
-    177..205 '{     ...     }': ()
-    191..192 'h': {unknown}
-    195..198 'val': {unknown}
-    215..221 'lambda': |u64, u64, i32| -> i32
-    224..256 '|a: u6...b; c }': |u64, u64, i32| -> i32
-    225..226 'a': u64
-    233..234 'b': u64
-    236..237 'c': i32
-    244..256 '{ a + b; c }': i32
-    246..247 'a': u64
-    246..251 'a + b': u64
-    250..251 'b': u64
-    253..254 'c': i32
-    267..279 'ref ref_to_x': &&i32
-    282..283 'x': &i32
-    293..302 'mut mut_x': &i32
-    305..306 'x': &i32
-    316..336 'ref mu...f_to_x': &mut &i32
-    339..340 'x': &i32
-    350..351 'k': &mut &i32
-    354..366 'mut_ref_to_x': &mut &i32
+    8..9 'x': &i32
+    17..368 '{     ...o_x; }': ()
+    27..28 'y': &i32
+    31..32 'x': &i32
+    42..44 '&z': &i32
+    43..44 'z': i32
+    47..48 'x': &i32
+    58..59 'a': i32
+    62..63 'z': i32
+    73..79 '(c, d)': (i32, &str)
+    74..75 'c': i32
+    77..78 'd': &str
+    82..94 '(1, "hello")': (i32, &str)
+    83..84 '1': i32
+    86..93 '"hello"': &str
+    101..151 'for (e...     }': ()
+    105..111 '(e, f)': ({unknown}, {unknown})
+    106..107 'e': {unknown}
+    109..110 'f': {unknown}
+    115..124 'some_iter': {unknown}
+    125..151 '{     ...     }': ()
+    139..140 'g': {unknown}
+    143..144 'e': {unknown}
+    157..204 'if let...     }': ()
+    164..169 '[val]': [{unknown}]
+    165..168 'val': {unknown}
+    172..175 'opt': [{unknown}]
+    176..204 '{     ...     }': ()
+    190..191 'h': {unknown}
+    194..197 'val': {unknown}
+    214..220 'lambda': |u64, u64, i32| -> i32
+    223..255 '|a: u6...b; c }': |u64, u64, i32| -> i32
+    224..225 'a': u64
+    232..233 'b': u64
+    235..236 'c': i32
+    243..255 '{ a + b; c }': i32
+    245..246 'a': u64
+    245..250 'a + b': u64
+    249..250 'b': u64
+    252..253 'c': i32
+    266..278 'ref ref_to_x': &&i32
+    281..282 'x': &i32
+    292..301 'mut mut_x': &i32
+    304..305 'x': &i32
+    315..335 'ref mu...f_to_x': &mut &i32
+    338..339 'x': &i32
+    349..350 'k': &mut &i32
+    353..365 'mut_ref_to_x': &mut &i32
     "###
     );
 }
@@ -97,47 +97,47 @@ fn test(x: &i32) {
 }
 "#, true),
         @r###"
-    18..29 '{ loop {} }': T
-    20..27 'loop {}': !
-    25..27 '{}': ()
-    38..39 'x': &i32
-    47..209 '{     ...) {} }': ()
-    53..76 'if let...y() {}': ()
-    60..65 '"foo"': &str
-    60..65 '"foo"': &str
-    68..71 'any': fn any<&str>() -> &str
-    68..73 'any()': &str
-    74..76 '{}': ()
-    81..100 'if let...y() {}': ()
-    88..89 '1': i32
-    88..89 '1': i32
-    92..95 'any': fn any<i32>() -> i32
-    92..97 'any()': i32
-    98..100 '{}': ()
-    105..127 'if let...y() {}': ()
-    112..116 '1u32': u32
-    112..116 '1u32': u32
-    119..122 'any': fn any<u32>() -> u32
-    119..124 'any()': u32
-    125..127 '{}': ()
-    132..154 'if let...y() {}': ()
-    139..143 '1f32': f32
-    139..143 '1f32': f32
-    146..149 'any': fn any<f32>() -> f32
-    146..151 'any()': f32
-    152..154 '{}': ()
-    159..180 'if let...y() {}': ()
-    166..169 '1.0': f64
-    166..169 '1.0': f64
-    172..175 'any': fn any<f64>() -> f64
-    172..177 'any()': f64
-    178..180 '{}': ()
-    185..207 'if let...y() {}': ()
-    192..196 'true': bool
-    192..196 'true': bool
-    199..202 'any': fn any<bool>() -> bool
-    199..204 'any()': bool
-    205..207 '{}': ()
+    17..28 '{ loop {} }': T
+    19..26 'loop {}': !
+    24..26 '{}': ()
+    37..38 'x': &i32
+    46..208 '{     ...) {} }': ()
+    52..75 'if let...y() {}': ()
+    59..64 '"foo"': &str
+    59..64 '"foo"': &str
+    67..70 'any': fn any<&str>() -> &str
+    67..72 'any()': &str
+    73..75 '{}': ()
+    80..99 'if let...y() {}': ()
+    87..88 '1': i32
+    87..88 '1': i32
+    91..94 'any': fn any<i32>() -> i32
+    91..96 'any()': i32
+    97..99 '{}': ()
+    104..126 'if let...y() {}': ()
+    111..115 '1u32': u32
+    111..115 '1u32': u32
+    118..121 'any': fn any<u32>() -> u32
+    118..123 'any()': u32
+    124..126 '{}': ()
+    131..153 'if let...y() {}': ()
+    138..142 '1f32': f32
+    138..142 '1f32': f32
+    145..148 'any': fn any<f32>() -> f32
+    145..150 'any()': f32
+    151..153 '{}': ()
+    158..179 'if let...y() {}': ()
+    165..168 '1.0': f64
+    165..168 '1.0': f64
+    171..174 'any': fn any<f64>() -> f64
+    171..176 'any()': f64
+    177..179 '{}': ()
+    184..206 'if let...y() {}': ()
+    191..195 'true': bool
+    191..195 'true': bool
+    198..201 'any': fn any<bool>() -> bool
+    198..203 'any()': bool
+    204..206 '{}': ()
     "###
     );
 }
@@ -152,16 +152,16 @@ fn test(x: &i32) {
 }
 "#, true),
         @r###"
-    9..10 'x': &i32
-    18..76 '{     ...2 {} }': ()
-    24..46 'if let...u32 {}': ()
-    31..36 '1..76': u32
-    39..43 '2u32': u32
-    44..46 '{}': ()
-    51..74 'if let...u32 {}': ()
-    58..64 '1..=76': u32
-    67..71 '2u32': u32
-    72..74 '{}': ()
+    8..9 'x': &i32
+    17..75 '{     ...2 {} }': ()
+    23..45 'if let...u32 {}': ()
+    30..35 '1..76': u32
+    38..42 '2u32': u32
+    43..45 '{}': ()
+    50..73 'if let...u32 {}': ()
+    57..63 '1..=76': u32
+    66..70 '2u32': u32
+    71..73 '{}': ()
     "###
     );
 }
@@ -178,19 +178,19 @@ fn test() {
 }
 "#),
     @r###"
-    28..79 '{     ...(1); }': ()
-    38..42 'A(n)': A<i32>
-    40..41 'n': &i32
-    45..50 '&A(1)': &A<i32>
-    46..47 'A': A<i32>(i32) -> A<i32>
-    46..50 'A(1)': A<i32>
-    48..49 '1': i32
-    60..64 'A(n)': A<i32>
-    62..63 'n': &mut i32
-    67..76 '&mut A(1)': &mut A<i32>
-    72..73 'A': A<i32>(i32) -> A<i32>
-    72..76 'A(1)': A<i32>
-    74..75 '1': i32
+    27..78 '{     ...(1); }': ()
+    37..41 'A(n)': A<i32>
+    39..40 'n': &i32
+    44..49 '&A(1)': &A<i32>
+    45..46 'A': A<i32>(i32) -> A<i32>
+    45..49 'A(1)': A<i32>
+    47..48 '1': i32
+    59..63 'A(n)': A<i32>
+    61..62 'n': &mut i32
+    66..75 '&mut A(1)': &mut A<i32>
+    71..72 'A': A<i32>(i32) -> A<i32>
+    71..75 'A(1)': A<i32>
+    73..74 '1': i32
     "###
     );
 }
@@ -206,18 +206,18 @@ fn test() {
 }
 "#),
     @r###"
-    11..57 '{     ...= v; }': ()
-    21..22 'v': &(i32, &i32)
-    25..33 '&(1, &2)': &(i32, &i32)
-    26..33 '(1, &2)': (i32, &i32)
-    27..28 '1': i32
-    30..32 '&2': &i32
-    31..32 '2': i32
-    43..50 '(_, &w)': (i32, &i32)
-    44..45 '_': i32
-    47..49 '&w': &i32
-    48..49 'w': i32
-    53..54 'v': &(i32, &i32)
+    10..56 '{     ...= v; }': ()
+    20..21 'v': &(i32, &i32)
+    24..32 '&(1, &2)': &(i32, &i32)
+    25..32 '(1, &2)': (i32, &i32)
+    26..27 '1': i32
+    29..31 '&2': &i32
+    30..31 '2': i32
+    42..49 '(_, &w)': (i32, &i32)
+    43..44 '_': i32
+    46..48 '&w': &i32
+    47..48 'w': i32
+    52..53 'v': &(i32, &i32)
     "###
     );
 }
@@ -242,30 +242,87 @@ fn test() {
 }
 "#),
     @r###"
-    11..210 '{     ...   } }': ()
-    21..26 'slice': &[f64]
-    37..43 '&[0.0]': &[f64; _]
-    38..43 '[0.0]': [f64; _]
-    39..42 '0.0': f64
-    49..208 'match ...     }': ()
-    55..60 'slice': &[f64]
-    71..74 '&[]': &[f64]
-    72..74 '[]': [f64]
-    78..80 '{}': ()
-    90..94 '&[a]': &[f64]
-    91..94 '[a]': [f64]
-    92..93 'a': f64
-    98..124 '{     ...     }': ()
-    112..113 'a': f64
-    134..141 '&[b, c]': &[f64]
-    135..141 '[b, c]': [f64]
-    136..137 'b': f64
-    139..140 'c': f64
-    145..186 '{     ...     }': ()
-    159..160 'b': f64
-    174..175 'c': f64
-    195..196 '_': &[f64]
-    200..202 '{}': ()
+    10..209 '{     ...   } }': ()
+    20..25 'slice': &[f64]
+    36..42 '&[0.0]': &[f64; _]
+    37..42 '[0.0]': [f64; _]
+    38..41 '0.0': f64
+    48..207 'match ...     }': ()
+    54..59 'slice': &[f64]
+    70..73 '&[]': &[f64]
+    71..73 '[]': [f64]
+    77..79 '{}': ()
+    89..93 '&[a]': &[f64]
+    90..93 '[a]': [f64]
+    91..92 'a': f64
+    97..123 '{     ...     }': ()
+    111..112 'a': f64
+    133..140 '&[b, c]': &[f64]
+    134..140 '[b, c]': [f64]
+    135..136 'b': f64
+    138..139 'c': f64
+    144..185 '{     ...     }': ()
+    158..159 'b': f64
+    173..174 'c': f64
+    194..195 '_': &[f64]
+    199..201 '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_string_literal() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn test() {
+    let s: &str = "hello";
+    match s {
+        "hello" => {}
+        _ => {}
+    }
+}
+"#, true),
+    @r###"
+    10..98 '{     ...   } }': ()
+    20..21 's': &str
+    30..37 '"hello"': &str
+    43..96 'match ...     }': ()
+    49..50 's': &str
+    61..68 '"hello"': &str
+    61..68 '"hello"': &str
+    72..74 '{}': ()
+    83..84 '_': &str
+    88..90 '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_or() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn test() {
+    let s: &str = "hello";
+    match s {
+        "hello" | "world" => {}
+        _ => {}
+    }
+}
+"#, true),
+    @r###"
+    10..108 '{     ...   } }': ()
+    20..21 's': &str
+    30..37 '"hello"': &str
+    43..106 'match ...     }': ()
+    49..50 's': &str
+    61..68 '"hello"': &str
+    61..68 '"hello"': &str
+    61..78 '"hello...world"': &str
+    71..78 '"world"': &str
+    71..78 '"world"': &str
+    82..84 '{}': ()
+    93..94 '_': &str
+    98..100 '{}': ()
     "###
     );
 }
@@ -288,25 +345,25 @@ fn test() {
 }
 "#),
     @r###"
-    11..180 '{     ...   } }': ()
-    21..24 'arr': [f64; _]
-    37..47 '[0.0, 1.0]': [f64; _]
-    38..41 '0.0': f64
-    43..46 '1.0': f64
-    53..178 'match ...     }': ()
-    59..62 'arr': [f64; _]
-    73..81 '[1.0, a]': [f64; _]
-    74..77 '1.0': f64
-    74..77 '1.0': f64
-    79..80 'a': f64
-    85..111 '{     ...     }': ()
-    99..100 'a': f64
-    121..127 '[b, c]': [f64; _]
-    122..123 'b': f64
-    125..126 'c': f64
-    131..172 '{     ...     }': ()
-    145..146 'b': f64
-    160..161 'c': f64
+    10..179 '{     ...   } }': ()
+    20..23 'arr': [f64; _]
+    36..46 '[0.0, 1.0]': [f64; _]
+    37..40 '0.0': f64
+    42..45 '1.0': f64
+    52..177 'match ...     }': ()
+    58..61 'arr': [f64; _]
+    72..80 '[1.0, a]': [f64; _]
+    73..76 '1.0': f64
+    73..76 '1.0': f64
+    78..79 'a': f64
+    84..110 '{     ...     }': ()
+    98..99 'a': f64
+    120..126 '[b, c]': [f64; _]
+    121..122 'b': f64
+    124..125 'c': f64
+    130..171 '{     ...     }': ()
+    144..145 'b': f64
+    159..160 'c': f64
     "###
     );
 }
@@ -339,31 +396,31 @@ fn test() {
 }
 "#),
         @r###"
-    68..289 '{     ...  d; }': ()
-    78..79 'e': E
-    82..95 'E::A { x: 3 }': E
-    92..93 '3': usize
-    106..113 'S(y, z)': S
-    108..109 'y': u32
-    111..112 'z': E
-    116..119 'foo': S
-    129..148 'E::A {..._var }': E
-    139..146 'new_var': usize
-    151..152 'e': E
-    159..245 'match ...     }': usize
-    165..166 'e': E
-    177..187 'E::A { x }': E
-    184..185 'x': usize
-    191..192 'x': usize
-    202..206 'E::B': E
-    210..213 'foo': bool
-    217..218 '1': usize
-    228..232 'E::B': E
-    236..238 '10': usize
-    256..275 'ref d ...{ .. }': &E
-    264..275 'E::A { .. }': E
-    278..279 'e': E
-    285..286 'd': &E
+    67..288 '{     ...  d; }': ()
+    77..78 'e': E
+    81..94 'E::A { x: 3 }': E
+    91..92 '3': usize
+    105..112 'S(y, z)': S
+    107..108 'y': u32
+    110..111 'z': E
+    115..118 'foo': S
+    128..147 'E::A {..._var }': E
+    138..145 'new_var': usize
+    150..151 'e': E
+    158..244 'match ...     }': usize
+    164..165 'e': E
+    176..186 'E::A { x }': E
+    183..184 'x': usize
+    190..191 'x': usize
+    201..205 'E::B': E
+    209..212 'foo': bool
+    216..217 '1': usize
+    227..231 'E::B': E
+    235..237 '10': usize
+    255..274 'ref d ...{ .. }': &E
+    263..274 'E::A { .. }': E
+    277..278 'e': E
+    284..285 'd': &E
     "###
     );
 }
@@ -389,20 +446,20 @@ impl E {
 }
 "#),
         @r###"
-    76..218 '{     ...     }': ()
-    86..211 'match ...     }': ()
-    93..100 'loop {}': !
-    98..100 '{}': ()
-    116..129 'Self::A { x }': E
-    126..127 'x': usize
-    133..139 '{ x; }': ()
-    135..136 'x': usize
-    153..163 'Self::B(x)': E
-    161..162 'x': usize
-    167..173 '{ x; }': ()
-    169..170 'x': usize
-    187..194 'Self::C': E
-    198..200 '{}': ()
+    75..217 '{     ...     }': ()
+    85..210 'match ...     }': ()
+    92..99 'loop {}': !
+    97..99 '{}': ()
+    115..128 'Self::A { x }': E
+    125..126 'x': usize
+    132..138 '{ x; }': ()
+    134..135 'x': usize
+    152..162 'Self::B(x)': E
+    160..161 'x': usize
+    166..172 '{ x; }': ()
+    168..169 'x': usize
+    186..193 'Self::C': E
+    197..199 '{}': ()
     "###
     );
 }
@@ -430,23 +487,23 @@ fn test(a1: A<u32>, o: Option<u64>) {
 }
 "#),
         @r###"
-    79..81 'a1': A<u32>
-    91..92 'o': Option<u64>
-    107..244 '{     ...  }; }': ()
-    117..128 'A { x: x2 }': A<u32>
-    124..126 'x2': u32
-    131..133 'a1': A<u32>
-    143..161 'A::<i6...: x3 }': A<i64>
-    157..159 'x3': i64
-    164..174 'A { x: 1 }': A<i64>
-    171..172 '1': i64
-    180..241 'match ...     }': u64
-    186..187 'o': Option<u64>
-    198..213 'Option::Some(t)': Option<u64>
-    211..212 't': u64
-    217..218 't': u64
-    228..229 '_': Option<u64>
-    233..234 '1': u64
+    78..80 'a1': A<u32>
+    90..91 'o': Option<u64>
+    106..243 '{     ...  }; }': ()
+    116..127 'A { x: x2 }': A<u32>
+    123..125 'x2': u32
+    130..132 'a1': A<u32>
+    142..160 'A::<i6...: x3 }': A<i64>
+    156..158 'x3': i64
+    163..173 'A { x: 1 }': A<i64>
+    170..171 '1': i64
+    179..240 'match ...     }': u64
+    185..186 'o': Option<u64>
+    197..212 'Option::Some(t)': Option<u64>
+    210..211 't': u64
+    216..217 't': u64
+    227..228 '_': Option<u64>
+    232..233 '1': u64
     "###
     );
 }
@@ -470,27 +527,27 @@ fn test() {
 }
 "#, true),
         @r###"
-    74..75 '1': usize
-    88..310 '{     ...atch }': ()
-    98..99 'a': Option<u32>
-    115..119 'None': Option<u32>
-    129..130 'b': Option<i64>
-    146..183 'match ...     }': Option<i64>
-    152..153 'a': Option<u32>
-    164..168 'None': Option<u32>
-    172..176 'None': Option<i64>
-    193..194 '_': ()
-    201..224 'match ... Foo }': Foo
-    207..209 '()': ()
-    212..215 'Foo': Foo
-    219..222 'Foo': Foo
-    255..256 '_': ()
-    263..286 'match ... Bar }': usize
-    269..271 '()': ()
-    274..277 'Bar': usize
-    281..284 'Bar': usize
-    201..224: expected (), got Foo
-    263..286: expected (), got usize
+    73..74 '1': usize
+    87..309 '{     ...atch }': ()
+    97..98 'a': Option<u32>
+    114..118 'None': Option<u32>
+    128..129 'b': Option<i64>
+    145..182 'match ...     }': Option<i64>
+    151..152 'a': Option<u32>
+    163..167 'None': Option<u32>
+    171..175 'None': Option<i64>
+    192..193 '_': ()
+    200..223 'match ... Foo }': Foo
+    206..208 '()': ()
+    211..214 'Foo': Foo
+    218..221 'Foo': Foo
+    254..255 '_': ()
+    262..285 'match ... Bar }': usize
+    268..270 '()': ()
+    273..276 'Bar': usize
+    280..283 'Bar': usize
+    200..223: expected (), got Foo
+    262..285: expected (), got usize
     "###
     );
 }
@@ -507,18 +564,18 @@ fn main() {
         s if s.foo() => (),
     }
 }
-    "#), @"
-        28..32 'self': &S
-        42..51 '{ false }': bool
-        44..49 'false': bool
-        65..116 '{     ...   } }': ()
-        71..114 'match ...     }': ()
-        77..78 'S': S
-        89..90 's': S
-        94..95 's': S
-        94..101 's.foo()': bool
-        105..107 '()': ()
-    ")
+    "#), @r###"
+    27..31 'self': &S
+    41..50 '{ false }': bool
+    43..48 'false': bool
+    64..115 '{     ...   } }': ()
+    70..113 'match ...     }': ()
+    76..77 'S': S
+    88..89 's': S
+    93..94 's': S
+    93..100 's.foo()': bool
+    104..106 '()': ()
+    "###)
 }
 
 #[test]
@@ -538,35 +595,60 @@ fn test() {
 }
 "#),
         @r###"
-    94..95 't': T
-    100..101 'f': F
-    111..122 '{ loop {} }': U
-    113..120 'loop {}': !
-    118..120 '{}': ()
-    134..233 '{     ... x); }': ()
-    140..143 'foo': fn foo<&(i32, &str), i32, |&(i32, &str)| -> i32>(&(i32, &str), |&(i32, &str)| -> i32) -> i32
-    140..167 'foo(&(...y)| x)': i32
-    144..153 '&(1, "a")': &(i32, &str)
-    145..153 '(1, "a")': (i32, &str)
-    146..147 '1': i32
-    149..152 '"a"': &str
-    155..166 '|&(x, y)| x': |&(i32, &str)| -> i32
-    156..163 '&(x, y)': &(i32, &str)
-    157..163 '(x, y)': (i32, &str)
-    158..159 'x': i32
-    161..162 'y': &str
-    165..166 'x': i32
-    204..207 'foo': fn foo<&(i32, &str), &i32, |&(i32, &str)| -> &i32>(&(i32, &str), |&(i32, &str)| -> &i32) -> &i32
-    204..230 'foo(&(...y)| x)': &i32
-    208..217 '&(1, "a")': &(i32, &str)
-    209..217 '(1, "a")': (i32, &str)
-    210..211 '1': i32
-    213..216 '"a"': &str
-    219..229 '|(x, y)| x': |&(i32, &str)| -> &i32
-    220..226 '(x, y)': (i32, &str)
-    221..222 'x': &i32
-    224..225 'y': &&str
-    228..229 'x': &i32
+    93..94 't': T
+    99..100 'f': F
+    110..121 '{ loop {} }': U
+    112..119 'loop {}': !
+    117..119 '{}': ()
+    133..232 '{     ... x); }': ()
+    139..142 'foo': fn foo<&(i32, &str), i32, |&(i32, &str)| -> i32>(&(i32, &str), |&(i32, &str)| -> i32) -> i32
+    139..166 'foo(&(...y)| x)': i32
+    143..152 '&(1, "a")': &(i32, &str)
+    144..152 '(1, "a")': (i32, &str)
+    145..146 '1': i32
+    148..151 '"a"': &str
+    154..165 '|&(x, y)| x': |&(i32, &str)| -> i32
+    155..162 '&(x, y)': &(i32, &str)
+    156..162 '(x, y)': (i32, &str)
+    157..158 'x': i32
+    160..161 'y': &str
+    164..165 'x': i32
+    203..206 'foo': fn foo<&(i32, &str), &i32, |&(i32, &str)| -> &i32>(&(i32, &str), |&(i32, &str)| -> &i32) -> &i32
+    203..229 'foo(&(...y)| x)': &i32
+    207..216 '&(1, "a")': &(i32, &str)
+    208..216 '(1, "a")': (i32, &str)
+    209..210 '1': i32
+    212..215 '"a"': &str
+    218..228 '|(x, y)| x': |&(i32, &str)| -> &i32
+    219..225 '(x, y)': (i32, &str)
+    220..221 'x': &i32
+    223..224 'y': &&str
+    227..228 'x': &i32
+    "###
+    );
+}
+
+#[test]
+fn slice_tail_pattern() {
+    assert_snapshot!(
+        infer(r#"
+fn foo(params: &[i32]) {
+    match params {
+        [head, tail @ ..] => {
+        }
+    }
+}
+"#),
+        @r###"
+    7..13 'params': &[i32]
+    23..92 '{     ...   } }': ()
+    29..90 'match ...     }': ()
+    35..41 'params': &[i32]
+    52..69 '[head,... @ ..]': [i32]
+    53..57 'head': &i32
+    59..68 'tail @ ..': &[i32]
+    66..68 '..': [i32]
+    73..84 '{         }': ()
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 1f004bd63..4367621fc 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -1,10 +1,7 @@
 use insta::assert_snapshot;
-use ra_db::fixture::WithFixture;
 use test_utils::mark;
 
-use crate::test_db::TestDB;
-
-use super::infer;
+use super::{check_types, infer};
 
 #[test]
 fn bug_484() {
@@ -15,11 +12,11 @@ fn test() {
 }
 "#),
         @r###"
-    11..37 '{    l... {}; }': ()
-    20..21 'x': ()
-    24..34 'if true {}': ()
-    27..31 'true': bool
-    32..34 '{}': ()
+    10..36 '{    l... {}; }': ()
+    19..20 'x': ()
+    23..33 'if true {}': ()
+    26..30 'true': bool
+    31..33 '{}': ()
     "###
     );
 }
@@ -35,10 +32,10 @@ fn test(x: X) {
 }
 "#),
         @r###"
-    20..21 'x': X
-    26..47 '{     ...eld; }': ()
-    32..33 'x': X
-    32..44 'x.some_field': {unknown}
+    19..20 'x': X
+    25..46 '{     ...eld; }': ()
+    31..32 'x': X
+    31..43 'x.some_field': {unknown}
     "###
     );
 }
@@ -56,14 +53,14 @@ fn test() {
 }
 "#),
         @r###"
-    11..89 '{     ...   } }': ()
-    17..21 'X {}': {unknown}
-    27..87 'match ...     }': ()
-    33..34 'x': {unknown}
-    45..52 'A::B {}': {unknown}
-    56..58 '()': ()
-    68..74 'A::Y()': {unknown}
-    78..80 '()': ()
+    10..88 '{     ...   } }': ()
+    16..20 'X {}': {unknown}
+    26..86 'match ...     }': ()
+    32..33 'x': {unknown}
+    44..51 'A::B {}': {unknown}
+    55..57 '()': ()
+    67..73 'A::Y()': {unknown}
+    77..79 '()': ()
     "###
     );
 }
@@ -78,12 +75,12 @@ fn quux() {
 }
 "#),
         @r###"
-    11..41 '{     ...+ y; }': ()
-    21..22 'y': i32
-    25..27 '92': i32
-    33..34 '1': i32
-    33..38 '1 + y': i32
-    37..38 'y': i32
+    10..40 '{     ...+ y; }': ()
+    20..21 'y': i32
+    24..26 '92': i32
+    32..33 '1': i32
+    32..37 '1 + y': i32
+    36..37 'y': i32
     "###
     );
 }
@@ -100,13 +97,13 @@ fn test() {
 }
 "#),
         @r###"
-    11..48 '{     ...&y]; }': ()
-    21..22 'y': &{unknown}
-    25..32 'unknown': &{unknown}
-    38..45 '[y, &y]': [&&{unknown}; _]
-    39..40 'y': &{unknown}
-    42..44 '&y': &&{unknown}
-    43..44 'y': &{unknown}
+    10..47 '{     ...&y]; }': ()
+    20..21 'y': &{unknown}
+    24..31 'unknown': &{unknown}
+    37..44 '[y, &y]': [&&{unknown}; _]
+    38..39 'y': &{unknown}
+    41..43 '&y': &&{unknown}
+    42..43 'y': &{unknown}
     "###
     );
 }
@@ -122,20 +119,20 @@ fn test() {
 }
 "#),
         @r###"
-    11..80 '{     ...x)]; }': ()
-    21..22 'x': &&{unknown}
-    25..32 'unknown': &&{unknown}
-    42..43 'y': &&{unknown}
-    46..53 'unknown': &&{unknown}
-    59..77 '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); _]
-    60..66 '(x, y)': (&&&{unknown}, &&&{unknown})
-    61..62 'x': &&{unknown}
-    64..65 'y': &&{unknown}
-    68..76 '(&y, &x)': (&&&{unknown}, &&&{unknown})
-    69..71 '&y': &&&{unknown}
-    70..71 'y': &&{unknown}
-    73..75 '&x': &&&{unknown}
-    74..75 'x': &&{unknown}
+    10..79 '{     ...x)]; }': ()
+    20..21 'x': &&{unknown}
+    24..31 'unknown': &&{unknown}
+    41..42 'y': &&{unknown}
+    45..52 'unknown': &&{unknown}
+    58..76 '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); _]
+    59..65 '(x, y)': (&&&{unknown}, &&&{unknown})
+    60..61 'x': &&{unknown}
+    63..64 'y': &&{unknown}
+    67..75 '(&y, &x)': (&&&{unknown}, &&&{unknown})
+    68..70 '&y': &&&{unknown}
+    69..70 'y': &&{unknown}
+    72..74 '&x': &&&{unknown}
+    73..74 'x': &&{unknown}
     "###
     );
 }
@@ -157,12 +154,12 @@ fn write() {
 }
 "#),
         @r###"
-    54..139 '{     ...   } }': ()
-    60..137 'match ...     }': ()
-    66..83 'someth...nknown': Maybe<{unknown}>
-    94..124 'Maybe:...thing)': Maybe<{unknown}>
-    106..123 'ref mu...ething': &mut {unknown}
-    128..130 '()': ()
+    53..138 '{     ...   } }': ()
+    59..136 'match ...     }': ()
+    65..82 'someth...nknown': Maybe<{unknown}>
+    93..123 'Maybe:...thing)': Maybe<{unknown}>
+    105..122 'ref mu...ething': &mut {unknown}
+    127..129 '()': ()
     "###
     );
 }
@@ -178,13 +175,13 @@ fn test_line_buffer() {
 }
 "#),
         @r###"
-    23..53 '{     ...n']; }': ()
-    29..50 '&[0, b...b'\n']': &[u8; _]
-    30..50 '[0, b'...b'\n']': [u8; _]
-    31..32 '0': u8
-    34..39 'b'\n'': u8
-    41..42 '1': u8
-    44..49 'b'\n'': u8
+    22..52 '{     ...n']; }': ()
+    28..49 '&[0, b...b'\n']': &[u8; _]
+    29..49 '[0, b'...b'\n']': [u8; _]
+    30..31 '0': u8
+    33..38 'b'\n'': u8
+    40..41 '1': u8
+    43..48 'b'\n'': u8
     "###
     );
 }
@@ -201,14 +198,14 @@ pub fn compute() {
 }
 "#),
         @r###"
-    18..108 '{     ...   } }': ()
-    24..106 'match ...     }': ()
-    30..37 'nope!()': {unknown}
-    48..94 'SizeSk...tail }': {unknown}
-    82..86 'true': bool
-    82..86 'true': bool
-    88..92 'tail': {unknown}
-    98..100 '{}': ()
+    17..107 '{     ...   } }': ()
+    23..105 'match ...     }': ()
+    29..36 'nope!()': {unknown}
+    47..93 'SizeSk...tail }': {unknown}
+    81..85 'true': bool
+    81..85 'true': bool
+    87..91 'tail': {unknown}
+    97..99 '{}': ()
     "###
     );
 }
@@ -225,14 +222,14 @@ pub fn primitive_type() {
 }
 "#),
         @r###"
-    25..106 '{     ...   } }': ()
-    31..104 'match ...     }': ()
-    37..42 '*self': {unknown}
-    38..42 'self': {unknown}
-    53..91 'Borrow...), ..}': {unknown}
-    74..86 'Primitive(p)': {unknown}
-    84..85 'p': {unknown}
-    95..97 '{}': ()
+    24..105 '{     ...   } }': ()
+    30..103 'match ...     }': ()
+    36..41 '*self': {unknown}
+    37..41 'self': {unknown}
+    52..90 'Borrow...), ..}': {unknown}
+    73..85 'Primitive(p)': {unknown}
+    83..84 'p': {unknown}
+    94..96 '{}': ()
     "###
     );
 }
@@ -259,29 +256,29 @@ fn extra_compiler_flags() {
 }
 "#),
         @r###"
-    27..323 '{     ...   } }': ()
-    33..321 'for co...     }': ()
-    37..44 'content': &{unknown}
-    48..61 'doesnt_matter': {unknown}
-    62..321 '{     ...     }': ()
-    76..80 'name': &&{unknown}
-    83..167 'if doe...     }': &&{unknown}
-    86..99 'doesnt_matter': bool
-    100..129 '{     ...     }': &&{unknown}
-    114..119 'first': &&{unknown}
-    135..167 '{     ...     }': &&{unknown}
-    149..157 '&content': &&{unknown}
-    150..157 'content': &{unknown}
-    182..189 'content': &{unknown}
-    192..314 'if ICE...     }': &{unknown}
-    195..232 'ICE_RE..._VALUE': {unknown}
-    195..248 'ICE_RE...&name)': bool
-    242..247 '&name': &&&{unknown}
-    243..247 'name': &&{unknown}
-    249..277 '{     ...     }': &&{unknown}
-    263..267 'name': &&{unknown}
-    283..314 '{     ...     }': &{unknown}
-    297..304 'content': &{unknown}
+    26..322 '{     ...   } }': ()
+    32..320 'for co...     }': ()
+    36..43 'content': &{unknown}
+    47..60 'doesnt_matter': {unknown}
+    61..320 '{     ...     }': ()
+    75..79 'name': &&{unknown}
+    82..166 'if doe...     }': &&{unknown}
+    85..98 'doesnt_matter': bool
+    99..128 '{     ...     }': &&{unknown}
+    113..118 'first': &&{unknown}
+    134..166 '{     ...     }': &&{unknown}
+    148..156 '&content': &&{unknown}
+    149..156 'content': &{unknown}
+    181..188 'content': &{unknown}
+    191..313 'if ICE...     }': &{unknown}
+    194..231 'ICE_RE..._VALUE': {unknown}
+    194..247 'ICE_RE...&name)': bool
+    241..246 '&name': &&&{unknown}
+    242..246 'name': &&{unknown}
+    248..276 '{     ...     }': &&{unknown}
+    262..266 'name': &&{unknown}
+    282..313 '{     ...     }': &{unknown}
+    296..303 'content': &{unknown}
     "###
     );
 }
@@ -302,11 +299,11 @@ fn test<R>(query_response: Canonical<QueryResponse<R>>) {
 }
 "#),
         @r###"
-    92..106 'query_response': Canonical<QueryResponse<R>>
-    137..167 '{     ...lue; }': ()
-    143..164 '&query....value': &QueryResponse<R>
-    144..158 'query_response': Canonical<QueryResponse<R>>
-    144..164 'query_....value': QueryResponse<R>
+    91..105 'query_response': Canonical<QueryResponse<R>>
+    136..166 '{     ...lue; }': ()
+    142..163 '&query....value': &QueryResponse<R>
+    143..157 'query_response': Canonical<QueryResponse<R>>
+    143..163 'query_....value': QueryResponse<R>
     "###
     );
 }
@@ -322,9 +319,9 @@ fn test() {
 "#),
         @r###"
     !0..4 '0u32': u32
-    45..70 '{     ...()); }': ()
-    55..56 'a': u32
-        "###
+    44..69 '{     ...()); }': ()
+    54..55 'a': u32
+    "###
     );
 }
 
@@ -344,10 +341,10 @@ pub fn main_loop() {
 }
 "#),
     @r###"
-    144..146 '{}': ()
-    169..198 '{     ...t(); }': ()
-    175..193 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<{unknown}, FxHasher>
-    175..195 'FxHash...ault()': HashSet<{unknown}, FxHasher>
+    143..145 '{}': ()
+    168..197 '{     ...t(); }': ()
+    174..192 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<{unknown}, FxHasher>
+    174..194 'FxHash...ault()': HashSet<{unknown}, FxHasher>
     "###
     );
 }
@@ -395,22 +392,22 @@ fn test() {
 }
 "#),
         @r###"
-    26..53 '{     ...oo() }': ()
-    32..49 '<Trait...>::foo': {unknown}
-    32..51 '<Trait...:foo()': ()
+    25..52 '{     ...oo() }': ()
+    31..48 '<Trait...>::foo': {unknown}
+    31..50 '<Trait...:foo()': ()
     "###
     );
 }
 
 #[test]
 fn issue_2683_chars_impl() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
 fn test() {
     let chars: std::str::Chars<'_>;
-    (chars.next(), chars.nth(1))<|>;
-}
+    (chars.next(), chars.nth(1));
+} //^ (Option<char>, Option<char>)
 
 //- /std.rs crate:std
 #[prelude_import]
@@ -449,15 +446,12 @@ pub mod str {
 }
 "#,
     );
-
-    assert_eq!("(Option<char>, Option<char>)", super::type_at_pos(&db, pos));
 }
 
 #[test]
 fn issue_3642_bad_macro_stackover() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs
 #[macro_export]
 macro_rules! match_ast {
     (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
@@ -472,7 +466,8 @@ macro_rules! match_ast {
 }
 
 fn main() {
-    let anchor<|> = match_ast! {
+    let anchor = match_ast! {
+       //^ ()
         match parent {
             as => {},
             _ => return None
@@ -480,8 +475,6 @@ fn main() {
     };
 }"#,
     );
-
-    assert_eq!("()", super::type_at_pos(&db, pos));
 }
 
 #[test]
@@ -495,13 +488,15 @@ fn foo(params: &[usize]) {
 }
 "#),
         @r###"
-    8..14 'params': &[usize]
-    26..81 '{     ...   } }': ()
-    32..79 'match ...     }': ()
-    38..44 'params': &[usize]
-    55..67 '[ps @ .., _]': [usize]
-    65..66 '_': usize
-    71..73 '{}': ()
+    7..13 'params': &[usize]
+    25..80 '{     ...   } }': ()
+    31..78 'match ...     }': ()
+    37..43 'params': &[usize]
+    54..66 '[ps @ .., _]': [usize]
+    55..62 'ps @ ..': &[usize]
+    60..62 '..': [usize]
+    64..65 '_': usize
+    70..72 '{}': ()
     "###
     );
 }
@@ -522,13 +517,13 @@ fn foo(b: Bar) {
 }
 "#),
         @r###"
-    36..37 'b': Bar
-    44..96 '{     ...   } }': ()
-    50..94 'match ...     }': ()
-    56..57 'b': Bar
-    68..81 'Bar { a: .. }': Bar
-    77..79 '..': bool
-    85..87 '{}': ()
+    35..36 'b': Bar
+    43..95 '{     ...   } }': ()
+    49..93 'match ...     }': ()
+    55..56 'b': Bar
+    67..80 'Bar { a: .. }': Bar
+    76..78 '..': bool
+    84..86 '{}': ()
     "###
     );
 }
@@ -549,16 +544,16 @@ fn main() {
     a.foo();
 }
 "#), @r###"
-    32..38 'FOO {}': FOO
-    64..68 'self': &FOO
-    70..72 '{}': ()
-    86..120 '{     ...o(); }': ()
-    96..97 'a': &FOO
-    100..104 '&FOO': &FOO
-    101..104 'FOO': FOO
-    110..111 'a': &FOO
-    110..117 'a.foo()': ()
-"###
+    31..37 'FOO {}': FOO
+    63..67 'self': &FOO
+    69..71 '{}': ()
+    85..119 '{     ...o(); }': ()
+    95..96 'a': &FOO
+    99..103 '&FOO': &FOO
+    100..103 'FOO': FOO
+    109..110 'a': &FOO
+    109..116 'a.foo()': ()
+    "###
     );
 }
 
@@ -580,17 +575,17 @@ fn main() {
     let _a = foo!();
 }
 "#), @r###"
-    45..60 '{     loop {} }': T
-    51..58 'loop {}': !
-    56..58 '{}': ()
+    44..59 '{     loop {} }': T
+    50..57 'loop {}': !
+    55..57 '{}': ()
     !0..31 '{letr:...g();r}': Foo
     !4..5 'r': Foo
     !18..26 'anything': fn anything<Foo>() -> Foo
     !18..28 'anything()': Foo
     !29..30 'r': Foo
-    164..188 '{     ...!(); }': ()
-    174..176 '_a': Foo
-"###);
+    163..187 '{     ...!(); }': ()
+    173..175 '_a': Foo
+    "###);
 }
 
 #[test]
@@ -623,13 +618,221 @@ where
 }
 "#),
         @r###"
-    66..70 'self': Self
-    268..272 'self': Self
-    467..471 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
-    489..523 '{     ...     }': ()
-    499..503 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
-    499..509 'self.order': O
-    499..516 'self.o...into()': dyn QueryFragment<DB>
+    65..69 'self': Self
+    267..271 'self': Self
+    466..470 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    488..522 '{     ...     }': ()
+    498..502 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    498..508 'self.order': O
+    498..515 'self.o...into()': dyn QueryFragment<DB>
+    "###
+    );
+}
+
+#[test]
+fn issue_4953() {
+    assert_snapshot!(
+        infer(r#"
+pub struct Foo(pub i64);
+impl Foo {
+    fn test() -> Self { Self(0i64) }
+}
+"#),
+        @r###"
+    58..72 '{ Self(0i64) }': Foo
+    60..64 'Self': Foo(i64) -> Foo
+    60..70 'Self(0i64)': Foo
+    65..69 '0i64': i64
+    "###
+    );
+    assert_snapshot!(
+        infer(r#"
+pub struct Foo<T>(pub T);
+impl Foo<i64> {
+    fn test() -> Self { Self(0i64) }
+}
+"#),
+        @r###"
+    64..78 '{ Self(0i64) }': Foo<i64>
+    66..70 'Self': Foo<i64>(i64) -> Foo<i64>
+    66..76 'Self(0i64)': Foo<i64>
+    71..75 '0i64': i64
+    "###
+    );
+}
+
+#[test]
+fn issue_4931() {
+    assert_snapshot!(
+        infer(r#"
+trait Div<T> {
+    type Output;
+}
+
+trait CheckedDiv: Div<()> {}
+
+trait PrimInt: CheckedDiv<Output = ()> {
+    fn pow(self);
+}
+
+fn check<T: PrimInt>(i: T) {
+    i.pow();
+}
+"#),
+        @r###"
+    117..121 'self': Self
+    148..149 'i': T
+    154..170 '{     ...w(); }': ()
+    160..161 'i': T
+    160..167 'i.pow()': ()
+    "###
+    );
+}
+
+#[test]
+fn issue_4885() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "coerce_unsized"]
+pub trait CoerceUnsized<T> {}
+
+trait Future {
+    type Output;
+}
+trait Foo<R> {
+    type Bar;
+}
+fn foo<R, K>(key: &K) -> impl Future<Output = K::Bar>
+where
+    K: Foo<R>,
+{
+    bar(key)
+}
+fn bar<R, K>(key: &K) -> impl Future<Output = K::Bar>
+where
+    K: Foo<R>,
+{
+}
+"#),
+        @r###"
+    136..139 'key': &K
+    198..214 '{     ...key) }': impl Future<Output = <K as Foo<R>>::Bar>
+    204..207 'bar': fn bar<R, K>(&K) -> impl Future<Output = <K as Foo<R>>::Bar>
+    204..212 'bar(key)': impl Future<Output = <K as Foo<R>>::Bar>
+    208..211 'key': &K
+    228..231 'key': &K
+    290..293 '{ }': ()
+    "###
+    );
+}
+
+#[test]
+fn issue_4800() {
+    assert_snapshot!(
+        infer(r#"
+trait Debug {}
+
+struct Foo<T>;
+
+type E1<T> = (T, T, T);
+type E2<T> = E1<E1<E1<(T, T, T)>>>;
+
+impl Debug for Foo<E2<()>> {}
+
+struct Request;
+
+pub trait Future {
+    type Output;
+}
+
+pub struct PeerSet<D>;
+
+impl<D> Service<Request> for PeerSet<D>
+where
+    D: Discover,
+    D::Key: Debug,
+{
+    type Error = ();
+    type Future = dyn Future<Output = Self::Error>;
+
+    fn call(&mut self) -> Self::Future {
+        loop {}
+    }
+}
+
+pub trait Discover {
+    type Key;
+}
+
+pub trait Service<Request> {
+    type Error;
+    type Future: Future<Output = Self::Error>;
+    fn call(&mut self) -> Self::Future;
+}
+"#),
+        @r###"
+    379..383 'self': &mut PeerSet<D>
+    401..424 '{     ...     }': dyn Future<Output = ()>
+    411..418 'loop {}': !
+    416..418 '{}': ()
+    575..579 'self': &mut Self
+    "###
+    );
+}
+
+#[test]
+fn issue_4966() {
+    assert_snapshot!(
+        infer(r#"
+pub trait IntoIterator {
+    type Item;
+}
+
+struct Repeat<A> { element: A }
+
+struct Map<F> { f: F }
+
+struct Vec<T> {}
+
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+}
+
+impl<T> Deref for Vec<T> {
+    type Target = [T];
+}
+
+fn from_iter<A, T: IntoIterator<Item = A>>(iter: T) -> Vec<A> {}
+
+fn main() {
+    let inner = Map { f: |_: &f64| 0.0 };
+
+    let repeat = Repeat { element: inner };
+
+    let vec = from_iter(repeat);
+
+    vec.foo_bar();
+}
+"#),
+        @r###"
+    270..274 'iter': T
+    289..291 '{}': ()
+    303..447 '{     ...r(); }': ()
+    313..318 'inner': Map<|&f64| -> f64>
+    321..345 'Map { ... 0.0 }': Map<|&f64| -> f64>
+    330..343 '|_: &f64| 0.0': |&f64| -> f64
+    331..332 '_': &f64
+    340..343 '0.0': f64
+    356..362 'repeat': Repeat<Map<|&f64| -> f64>>
+    365..390 'Repeat...nner }': Repeat<Map<|&f64| -> f64>>
+    383..388 'inner': Map<|&f64| -> f64>
+    401..404 'vec': Vec<IntoIterator::Item<Repeat<Map<|&f64| -> f64>>>>
+    407..416 'from_iter': fn from_iter<IntoIterator::Item<Repeat<Map<|&f64| -> f64>>>, Repeat<Map<|&f64| -> f64>>>(Repeat<Map<|&f64| -> f64>>) -> Vec<IntoIterator::Item<Repeat<Map<|&f64| -> f64>>>>
+    407..424 'from_i...epeat)': Vec<IntoIterator::Item<Repeat<Map<|&f64| -> f64>>>>
+    417..423 'repeat': Repeat<Map<|&f64| -> f64>>
+    431..434 'vec': Vec<IntoIterator::Item<Repeat<Map<|&f64| -> f64>>>>
+    431..444 'vec.foo_bar()': {unknown}
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 88309157b..6d3e264af 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -1,19 +1,17 @@
-use super::{infer, type_at, type_at_pos};
-use crate::test_db::TestDB;
 use insta::assert_snapshot;
-use ra_db::fixture::WithFixture;
+
+use super::{check_types, infer};
 
 #[test]
 fn infer_box() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
-
 fn test() {
     let x = box 1;
     let t = (x, box x, box &1, box [1]);
-    t<|>;
-}
+    t;
+} //^ (Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; _]>)
 
 //- /std.rs crate:std
 #[prelude_import] use prelude::*;
@@ -25,29 +23,24 @@ mod boxed {
         inner: *mut T,
     }
 }
-
 "#,
     );
-    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; _]>)", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_adt_self() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs
 enum Nat { Succ(Self), Demo(Nat), Zero }
 
 fn test() {
     let foo: Nat = Nat::Zero;
     if let Nat::Succ(x) = foo {
-        x<|>
-    }
+        x
+    } //^ Nat
 }
-
 "#,
     );
-    assert_eq!("Nat", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -64,9 +57,9 @@ impl S<u32> {
 }
 "#,
     ), @r###"
-    63..93 '{     ...     }': ()
-    73..86 'Self { x: 1 }': S<u32>
-    83..84 '1': u32
+    49..79 '{     ...     }': ()
+    59..72 'Self { x: 1 }': S<u32>
+    69..70 '1': u32
     "###);
 }
 
@@ -85,17 +78,17 @@ fn foo() {
 
 "#,
     ), @r###"
-    64..84 '{     ...1 }; }': ()
-    70..81 'SS { x: 1 }': S<u32>
-    78..79 '1': u32
+    50..70 '{     ...1 }; }': ()
+    56..67 'SS { x: 1 }': S<u32>
+    64..65 '1': u32
     "###);
 }
 
 #[test]
 fn infer_ranges() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 fn test() {
     let a = ..;
     let b = 1..;
@@ -105,10 +98,10 @@ fn test() {
     let f = 'a'..='z';
 
     let t = (a, b, c, d, e, f);
-    t<|>;
-}
+    t;
+} //^ (RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use prelude::*;
 mod prelude {}
 
@@ -135,29 +128,22 @@ pub mod ops {
 }
 "#,
     );
-    assert_eq!(
-        "(RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)",
-        type_at_pos(&db, pos),
-    );
 }
 
 #[test]
 fn infer_while_let() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs
 enum Option<T> { Some(T), None }
 
 fn test() {
     let foo: Option<f32> = None;
     while let Option::Some(x) = foo {
-        <|>x
-    }
+        x
+    } //^ f32
 }
-
 "#,
     );
-    assert_eq!("f32", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -175,19 +161,19 @@ fn test(a: u32, b: isize, c: !, d: &str) {
     1.0f32;
 }"#),
         @r###"
-    9..10 'a': u32
-    17..18 'b': isize
-    27..28 'c': !
-    33..34 'd': &str
-    42..121 '{     ...f32; }': ()
-    48..49 'a': u32
-    55..56 'b': isize
-    62..63 'c': !
-    69..70 'd': &str
-    76..82 '1usize': usize
-    88..94 '1isize': isize
-    100..106 '"test"': &str
-    112..118 '1.0f32': f32
+    8..9 'a': u32
+    16..17 'b': isize
+    26..27 'c': !
+    32..33 'd': &str
+    41..120 '{     ...f32; }': ()
+    47..48 'a': u32
+    54..55 'b': isize
+    61..62 'c': !
+    68..69 'd': &str
+    75..81 '1usize': usize
+    87..93 '1isize': isize
+    99..105 '"test"': &str
+    111..117 '1.0f32': f32
     "###
     );
 }
@@ -206,17 +192,17 @@ fn test() {
 }
 "#),
         @r###"
-    11..118 '{     ...= e; }': ()
-    21..22 'a': isize
-    25..31 '1isize': isize
-    41..42 'b': usize
-    52..53 '1': usize
-    63..64 'c': usize
-    67..68 'b': usize
-    78..79 'd': u32
-    94..95 'e': i32
-    105..106 'f': i32
-    114..115 'e': i32
+    10..117 '{     ...= e; }': ()
+    20..21 'a': isize
+    24..30 '1isize': isize
+    40..41 'b': usize
+    51..52 '1': usize
+    62..63 'c': usize
+    66..67 'b': usize
+    77..78 'd': u32
+    93..94 'e': i32
+    104..105 'f': i32
+    113..114 'e': i32
     "###
     );
 }
@@ -237,15 +223,15 @@ fn test() {
 }
 "#),
         @r###"
-    15..20 '{ 1 }': u32
-    17..18 '1': u32
-    48..53 '{ 1 }': u32
-    50..51 '1': u32
-    67..91 '{     ...c(); }': ()
-    73..74 'a': fn a() -> u32
-    73..76 'a()': u32
-    82..86 'b::c': fn c() -> u32
-    82..88 'b::c()': u32
+    14..19 '{ 1 }': u32
+    16..17 '1': u32
+    47..52 '{ 1 }': u32
+    49..50 '1': u32
+    66..90 '{     ...c(); }': ()
+    72..73 'a': fn a() -> u32
+    72..75 'a()': u32
+    81..85 'b::c': fn c() -> u32
+    81..87 'b::c()': u32
     "###
     );
 }
@@ -266,13 +252,13 @@ fn test() {
 }
 "#),
         @r###"
-    41..46 '{ 1 }': i32
-    43..44 '1': i32
-    60..93 '{     ...o(); }': ()
-    66..72 'S::foo': fn foo() -> i32
-    66..74 'S::foo()': i32
-    80..88 '<S>::foo': fn foo() -> i32
-    80..90 '<S>::foo()': i32
+    40..45 '{ 1 }': i32
+    42..43 '1': i32
+    59..92 '{     ...o(); }': ()
+    65..71 'S::foo': fn foo() -> i32
+    65..73 'S::foo()': i32
+    79..87 '<S>::foo': fn foo() -> i32
+    79..89 '<S>::foo()': i32
     "###
     );
 }
@@ -297,22 +283,22 @@ fn test() {
 }
 "#),
         @r###"
-    72..154 '{     ...a.c; }': ()
-    82..83 'c': C
-    86..87 'C': C(usize) -> C
-    86..90 'C(1)': C
-    88..89 '1': usize
-    96..97 'B': B
-    107..108 'a': A
-    114..133 'A { b:...C(1) }': A
-    121..122 'B': B
-    127..128 'C': C(usize) -> C
-    127..131 'C(1)': C
-    129..130 '1': usize
-    139..140 'a': A
-    139..142 'a.b': B
-    148..149 'a': A
-    148..151 'a.c': C
+    71..153 '{     ...a.c; }': ()
+    81..82 'c': C
+    85..86 'C': C(usize) -> C
+    85..89 'C(1)': C
+    87..88 '1': usize
+    95..96 'B': B
+    106..107 'a': A
+    113..132 'A { b:...C(1) }': A
+    120..121 'B': B
+    126..127 'C': C(usize) -> C
+    126..130 'C(1)': C
+    128..129 '1': usize
+    138..139 'a': A
+    138..141 'a.b': B
+    147..148 'a': A
+    147..150 'a.c': C
     "###
     );
 }
@@ -330,10 +316,33 @@ fn test() {
   E::V2;
 }"#),
         @r###"
-    48..82 '{   E:...:V2; }': ()
-    52..70 'E::V1 ...d: 1 }': E
-    67..68 '1': u32
-    74..79 'E::V2': E
+    47..81 '{   E:...:V2; }': ()
+    51..69 'E::V1 ...d: 1 }': E
+    66..67 '1': u32
+    73..78 'E::V2': E
+    "###
+    );
+}
+
+#[test]
+fn infer_union() {
+    assert_snapshot!(
+        infer(r#"
+union MyUnion {
+    foo: u32,
+    bar: f32,
+}
+
+unsafe fn baz(u: MyUnion) {
+    let inner = u.foo;
+}
+"#),
+        @r###"
+    61..62 'u': MyUnion
+    73..99 '{     ...foo; }': ()
+    83..88 'inner': u32
+    91..92 'u': MyUnion
+    91..96 'u.foo': u32
     "###
     );
 }
@@ -357,29 +366,29 @@ fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
 }
 "#),
         @r###"
-    9..10 'a': &u32
-    18..19 'b': &mut u32
-    31..32 'c': *const u32
-    46..47 'd': *mut u32
-    59..150 '{     ... *d; }': ()
-    65..66 'a': &u32
-    72..74 '*a': u32
-    73..74 'a': &u32
-    80..82 '&a': &&u32
-    81..82 'a': &u32
-    88..94 '&mut a': &mut &u32
-    93..94 'a': &u32
-    100..101 'b': &mut u32
-    107..109 '*b': u32
-    108..109 'b': &mut u32
-    115..117 '&b': &&mut u32
-    116..117 'b': &mut u32
-    123..124 'c': *const u32
-    130..132 '*c': u32
-    131..132 'c': *const u32
-    138..139 'd': *mut u32
-    145..147 '*d': u32
-    146..147 'd': *mut u32
+    8..9 'a': &u32
+    17..18 'b': &mut u32
+    30..31 'c': *const u32
+    45..46 'd': *mut u32
+    58..149 '{     ... *d; }': ()
+    64..65 'a': &u32
+    71..73 '*a': u32
+    72..73 'a': &u32
+    79..81 '&a': &&u32
+    80..81 'a': &u32
+    87..93 '&mut a': &mut &u32
+    92..93 'a': &u32
+    99..100 'b': &mut u32
+    106..108 '*b': u32
+    107..108 'b': &mut u32
+    114..116 '&b': &&mut u32
+    115..116 'b': &mut u32
+    122..123 'c': *const u32
+    129..131 '*c': u32
+    130..131 'c': *const u32
+    137..138 'd': *mut u32
+    144..146 '*d': u32
+    145..146 'd': *mut u32
     "###
     );
 }
@@ -394,12 +403,12 @@ fn test(a: i32) {
 }
 "#),
         @r###"
-    9..10 'a': i32
-    17..54 '{     ...t a; }': ()
-    23..33 '&raw mut a': *mut i32
-    32..33 'a': i32
-    39..51 '&raw const a': *const i32
-    50..51 'a': i32
+    8..9 'a': i32
+    16..53 '{     ...t a; }': ()
+    22..32 '&raw mut a': *mut i32
+    31..32 'a': i32
+    38..50 '&raw const a': *const i32
+    49..50 'a': i32
     "###
     );
 }
@@ -429,20 +438,20 @@ fn test() {
 }
 "##),
         @r###"
-    11..221 '{     ...o"#; }': ()
-    17..21 '5i32': i32
-    27..31 '5f32': f32
-    37..41 '5f64': f64
-    47..54 '"hello"': &str
-    60..68 'b"bytes"': &[u8; _]
-    74..77 ''c'': char
-    83..87 'b'b'': u8
-    93..97 '3.14': f64
-    103..107 '5000': i32
-    113..118 'false': bool
-    124..128 'true': bool
-    134..202 'r#"   ...    "#': &str
-    208..218 'br#"yolo"#': &[u8; _]
+    10..220 '{     ...o"#; }': ()
+    16..20 '5i32': i32
+    26..30 '5f32': f32
+    36..40 '5f64': f64
+    46..53 '"hello"': &str
+    59..67 'b"bytes"': &[u8; _]
+    73..76 ''c'': char
+    82..86 'b'b'': u8
+    92..96 '3.14': f64
+    102..106 '5000': i32
+    112..117 'false': bool
+    123..127 'true': bool
+    133..201 'r#"   ...    "#': &str
+    207..217 'br#"yolo"#': &[u8; _]
     "###
     );
 }
@@ -472,47 +481,47 @@ fn test(x: SomeType) {
 }
 "#),
         @r###"
-    27..28 'x': SomeType
-    40..272 '{     ...lo"; }': ()
-    50..51 'b': bool
-    54..59 'false': bool
-    69..70 'c': bool
-    73..75 '!b': bool
-    74..75 'b': bool
-    85..86 'a': i128
-    89..92 '100': i128
-    102..103 'd': i128
-    112..114 '-a': i128
-    113..114 'a': i128
-    124..125 'e': i32
-    128..132 '-100': i32
-    129..132 '100': i32
-    142..143 'f': bool
-    146..153 '!!!true': bool
-    147..153 '!!true': bool
-    148..153 '!true': bool
-    149..153 'true': bool
-    163..164 'g': i32
-    167..170 '!42': i32
-    168..170 '42': i32
-    180..181 'h': u32
-    184..190 '!10u32': u32
-    185..190 '10u32': u32
-    200..201 'j': i128
-    204..206 '!a': i128
-    205..206 'a': i128
-    212..217 '-3.14': f64
-    213..217 '3.14': f64
-    223..225 '!3': i32
-    224..225 '3': i32
-    231..233 '-x': {unknown}
-    232..233 'x': SomeType
-    239..241 '!x': {unknown}
-    240..241 'x': SomeType
-    247..255 '-"hello"': {unknown}
-    248..255 '"hello"': &str
-    261..269 '!"hello"': {unknown}
-    262..269 '"hello"': &str
+    26..27 'x': SomeType
+    39..271 '{     ...lo"; }': ()
+    49..50 'b': bool
+    53..58 'false': bool
+    68..69 'c': bool
+    72..74 '!b': bool
+    73..74 'b': bool
+    84..85 'a': i128
+    88..91 '100': i128
+    101..102 'd': i128
+    111..113 '-a': i128
+    112..113 'a': i128
+    123..124 'e': i32
+    127..131 '-100': i32
+    128..131 '100': i32
+    141..142 'f': bool
+    145..152 '!!!true': bool
+    146..152 '!!true': bool
+    147..152 '!true': bool
+    148..152 'true': bool
+    162..163 'g': i32
+    166..169 '!42': i32
+    167..169 '42': i32
+    179..180 'h': u32
+    183..189 '!10u32': u32
+    184..189 '10u32': u32
+    199..200 'j': i128
+    203..205 '!a': i128
+    204..205 'a': i128
+    211..216 '-3.14': f64
+    212..216 '3.14': f64
+    222..224 '!3': i32
+    223..224 '3': i32
+    230..232 '-x': {unknown}
+    231..232 'x': SomeType
+    238..240 '!x': {unknown}
+    239..240 'x': SomeType
+    246..254 '-"hello"': {unknown}
+    247..254 '"hello"': &str
+    260..268 '!"hello"': {unknown}
+    261..268 '"hello"': &str
     "###
     );
 }
@@ -535,26 +544,26 @@ fn test() -> &mut &f64 {
 }
 "#),
         @r###"
-    14..15 'x': u32
-    22..24 '{}': ()
-    78..231 '{     ...t &c }': &mut &f64
-    88..89 'a': u32
-    92..108 'unknow...nction': {unknown}
-    92..110 'unknow...tion()': u32
-    116..125 'takes_u32': fn takes_u32(u32)
-    116..128 'takes_u32(a)': ()
-    126..127 'a': u32
-    138..139 'b': i32
-    142..158 'unknow...nction': {unknown}
-    142..160 'unknow...tion()': i32
-    166..184 'S { i3...d: b }': S
-    181..182 'b': i32
-    194..195 'c': f64
-    198..214 'unknow...nction': {unknown}
-    198..216 'unknow...tion()': f64
-    222..229 '&mut &c': &mut &f64
-    227..229 '&c': &f64
-    228..229 'c': f64
+    13..14 'x': u32
+    21..23 '{}': ()
+    77..230 '{     ...t &c }': &mut &f64
+    87..88 'a': u32
+    91..107 'unknow...nction': {unknown}
+    91..109 'unknow...tion()': u32
+    115..124 'takes_u32': fn takes_u32(u32)
+    115..127 'takes_u32(a)': ()
+    125..126 'a': u32
+    137..138 'b': i32
+    141..157 'unknow...nction': {unknown}
+    141..159 'unknow...tion()': i32
+    165..183 'S { i3...d: b }': S
+    180..181 'b': i32
+    193..194 'c': f64
+    197..213 'unknow...nction': {unknown}
+    197..215 'unknow...tion()': f64
+    221..228 '&mut &c': &mut &f64
+    226..228 '&c': &f64
+    227..228 'c': f64
     "###
     );
 }
@@ -581,16 +590,16 @@ impl S {
 }
 "#),
         @r###"
-    34..38 'self': &S
-    40..61 '{     ...     }': ()
-    50..54 'self': &S
-    75..79 'self': &S
-    88..109 '{     ...     }': ()
-    98..102 'self': &S
-    133..153 '{     ...     }': S
-    143..147 'S {}': S
-    177..200 '{     ...     }': S
-    187..194 'Self {}': S
+    33..37 'self': &S
+    39..60 '{     ...     }': ()
+    49..53 'self': &S
+    74..78 'self': &S
+    87..108 '{     ...     }': ()
+    97..101 'self': &S
+    132..152 '{     ...     }': S
+    142..146 'S {}': S
+    176..199 '{     ...     }': S
+    186..193 'Self {}': S
     "###
     );
 }
@@ -624,17 +633,17 @@ impl E {
 }
 "#),
         @r###"
-    87..108 '{     ...     }': ()
-    97..101 'Self': S1
-    135..159 '{     ...     }': ()
-    145..149 'Self': S2(isize) -> S2
-    145..152 'Self(1)': S2
-    150..151 '1': isize
-    185..231 '{     ...     }': ()
-    195..203 'Self::V1': E
-    213..221 'Self::V2': V2(u32) -> E
-    213..224 'Self::V2(1)': E
-    222..223 '1': u32
+    86..107 '{     ...     }': ()
+    96..100 'Self': S1
+    134..158 '{     ...     }': ()
+    144..148 'Self': S2(isize) -> S2
+    144..151 'Self(1)': S2
+    149..150 '1': isize
+    184..230 '{     ...     }': ()
+    194..202 'Self::V1': E
+    212..220 'Self::V2': V2(u32) -> E
+    212..223 'Self::V2(1)': E
+    221..222 '1': u32
     "###
     );
 }
@@ -664,56 +673,56 @@ fn test() -> bool {
 }
 "#),
         @r###"
-    6..7 'x': bool
-    22..34 '{     0i32 }': i32
-    28..32 '0i32': i32
-    54..370 '{     ... < 3 }': bool
-    64..65 'x': bool
-    68..69 'a': bool
-    68..74 'a && b': bool
-    73..74 'b': bool
-    84..85 'y': bool
-    88..92 'true': bool
-    88..101 'true || false': bool
-    96..101 'false': bool
-    111..112 'z': bool
-    115..116 'x': bool
-    115..121 'x == y': bool
-    120..121 'y': bool
-    131..132 't': bool
-    135..136 'x': bool
-    135..141 'x != y': bool
-    140..141 'y': bool
-    151..162 'minus_forty': isize
-    172..180 '-40isize': isize
-    173..180 '40isize': isize
-    190..191 'h': bool
-    194..205 'minus_forty': isize
-    194..216 'minus_...ONST_2': bool
-    209..216 'CONST_2': isize
-    226..227 'c': i32
-    230..231 'f': fn f(bool) -> i32
-    230..239 'f(z || y)': i32
-    230..243 'f(z || y) + 5': i32
-    232..233 'z': bool
-    232..238 'z || y': bool
-    237..238 'y': bool
-    242..243 '5': i32
-    253..254 'd': {unknown}
-    257..258 'b': {unknown}
-    268..269 'g': ()
-    272..283 'minus_forty': isize
-    272..288 'minus_...y ^= i': ()
-    287..288 'i': isize
-    298..301 'ten': usize
-    311..313 '10': usize
-    323..336 'ten_is_eleven': bool
-    339..342 'ten': usize
-    339..354 'ten == some_num': bool
-    346..354 'some_num': usize
-    361..364 'ten': usize
-    361..368 'ten < 3': bool
-    367..368 '3': usize
+    5..6 'x': bool
+    21..33 '{     0i32 }': i32
+    27..31 '0i32': i32
+    53..369 '{     ... < 3 }': bool
+    63..64 'x': bool
+    67..68 'a': bool
+    67..73 'a && b': bool
+    72..73 'b': bool
+    83..84 'y': bool
+    87..91 'true': bool
+    87..100 'true || false': bool
+    95..100 'false': bool
+    110..111 'z': bool
+    114..115 'x': bool
+    114..120 'x == y': bool
+    119..120 'y': bool
+    130..131 't': bool
+    134..135 'x': bool
+    134..140 'x != y': bool
+    139..140 'y': bool
+    150..161 'minus_forty': isize
+    171..179 '-40isize': isize
+    172..179 '40isize': isize
+    189..190 'h': bool
+    193..204 'minus_forty': isize
+    193..215 'minus_...ONST_2': bool
+    208..215 'CONST_2': isize
+    225..226 'c': i32
+    229..230 'f': fn f(bool) -> i32
+    229..238 'f(z || y)': i32
+    229..242 'f(z || y) + 5': i32
+    231..232 'z': bool
+    231..237 'z || y': bool
+    236..237 'y': bool
+    241..242 '5': i32
+    252..253 'd': {unknown}
+    256..257 'b': {unknown}
+    267..268 'g': ()
+    271..282 'minus_forty': isize
+    271..287 'minus_...y ^= i': ()
+    286..287 'i': isize
+    297..300 'ten': usize
+    310..312 '10': usize
+    322..335 'ten_is_eleven': bool
+    338..341 'ten': usize
+    338..353 'ten == some_num': bool
+    345..353 'some_num': usize
+    360..363 'ten': usize
+    360..367 'ten < 3': bool
+    366..367 '3': usize
     "###
     );
 }
@@ -728,13 +737,13 @@ fn test() {
 }
 "#),
         @r###"
-    11..48 '{     ...5u8; }': ()
-    17..21 '1u32': u32
-    17..28 '1u32 << 5u8': u32
-    25..28 '5u8': u8
-    34..38 '1u32': u32
-    34..45 '1u32 >> 5u8': u32
-    42..45 '5u8': u8
+    10..47 '{     ...5u8; }': ()
+    16..20 '1u32': u32
+    16..27 '1u32 << 5u8': u32
+    24..27 '5u8': u8
+    33..37 '1u32': u32
+    33..44 '1u32 >> 5u8': u32
+    41..44 '5u8': u8
     "###
     );
 }
@@ -767,49 +776,49 @@ fn test2(a1: *const A, a2: *mut A) {
 }
 "#),
         @r###"
-    44..45 'a': A
-    50..213 '{     ...5.b; }': ()
-    60..62 'a1': A
-    65..66 'a': A
-    72..74 'a1': A
-    72..76 'a1.b': B
-    86..88 'a2': &A
-    91..93 '&a': &A
-    92..93 'a': A
-    99..101 'a2': &A
-    99..103 'a2.b': B
-    113..115 'a3': &mut A
-    118..124 '&mut a': &mut A
-    123..124 'a': A
-    130..132 'a3': &mut A
-    130..134 'a3.b': B
-    144..146 'a4': &&&&&&&A
-    149..157 '&&&&&&&a': &&&&&&&A
-    150..157 '&&&&&&a': &&&&&&A
-    151..157 '&&&&&a': &&&&&A
-    152..157 '&&&&a': &&&&A
-    153..157 '&&&a': &&&A
-    154..157 '&&a': &&A
-    155..157 '&a': &A
-    156..157 'a': A
-    163..165 'a4': &&&&&&&A
-    163..167 'a4.b': B
-    177..179 'a5': &mut &&mut &&mut A
-    182..200 '&mut &...&mut a': &mut &&mut &&mut A
-    187..200 '&&mut &&mut a': &&mut &&mut A
-    188..200 '&mut &&mut a': &mut &&mut A
-    193..200 '&&mut a': &&mut A
-    194..200 '&mut a': &mut A
-    199..200 'a': A
-    206..208 'a5': &mut &&mut &&mut A
-    206..210 'a5.b': B
-    224..226 'a1': *const A
-    238..240 'a2': *mut A
-    250..273 '{     ...2.b; }': ()
-    256..258 'a1': *const A
-    256..260 'a1.b': B
-    266..268 'a2': *mut A
-    266..270 'a2.b': B
+    43..44 'a': A
+    49..212 '{     ...5.b; }': ()
+    59..61 'a1': A
+    64..65 'a': A
+    71..73 'a1': A
+    71..75 'a1.b': B
+    85..87 'a2': &A
+    90..92 '&a': &A
+    91..92 'a': A
+    98..100 'a2': &A
+    98..102 'a2.b': B
+    112..114 'a3': &mut A
+    117..123 '&mut a': &mut A
+    122..123 'a': A
+    129..131 'a3': &mut A
+    129..133 'a3.b': B
+    143..145 'a4': &&&&&&&A
+    148..156 '&&&&&&&a': &&&&&&&A
+    149..156 '&&&&&&a': &&&&&&A
+    150..156 '&&&&&a': &&&&&A
+    151..156 '&&&&a': &&&&A
+    152..156 '&&&a': &&&A
+    153..156 '&&a': &&A
+    154..156 '&a': &A
+    155..156 'a': A
+    162..164 'a4': &&&&&&&A
+    162..166 'a4.b': B
+    176..178 'a5': &mut &&mut &&mut A
+    181..199 '&mut &...&mut a': &mut &&mut &&mut A
+    186..199 '&&mut &&mut a': &&mut &&mut A
+    187..199 '&mut &&mut a': &mut &&mut A
+    192..199 '&&mut a': &&mut A
+    193..199 '&mut a': &mut A
+    198..199 'a': A
+    205..207 'a5': &mut &&mut &&mut A
+    205..209 'a5.b': B
+    223..225 'a1': *const A
+    237..239 'a2': *mut A
+    249..272 '{     ...2.b; }': ()
+    255..257 'a1': *const A
+    255..259 'a1.b': B
+    265..267 'a2': *mut A
+    265..269 'a2.b': B
     "###
     );
 }
@@ -846,30 +855,30 @@ fn test() {
 }
 "#),
         @r###"
-    68..72 'self': &Self
-    139..143 'self': &A<T>
-    151..174 '{     ...     }': &T
-    161..168 '&self.0': &T
-    162..166 'self': &A<T>
-    162..168 'self.0': T
-    255..259 'self': &B<T>
-    278..301 '{     ...     }': &T
-    288..295 '&self.0': &T
-    289..293 'self': &B<T>
-    289..295 'self.0': T
-    315..353 '{     ...))); }': ()
-    325..326 't': &i32
-    329..335 'A::foo': fn foo<i32>(&A<i32>) -> &i32
-    329..350 'A::foo...42))))': &i32
-    336..349 '&&B(B(A(42)))': &&B<B<A<i32>>>
-    337..349 '&B(B(A(42)))': &B<B<A<i32>>>
-    338..339 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
-    338..349 'B(B(A(42)))': B<B<A<i32>>>
-    340..341 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
-    340..348 'B(A(42))': B<A<i32>>
-    342..343 'A': A<i32>(i32) -> A<i32>
-    342..347 'A(42)': A<i32>
-    344..346 '42': i32
+    67..71 'self': &Self
+    138..142 'self': &A<T>
+    150..173 '{     ...     }': &T
+    160..167 '&self.0': &T
+    161..165 'self': &A<T>
+    161..167 'self.0': T
+    254..258 'self': &B<T>
+    277..300 '{     ...     }': &T
+    287..294 '&self.0': &T
+    288..292 'self': &B<T>
+    288..294 'self.0': T
+    314..352 '{     ...))); }': ()
+    324..325 't': &i32
+    328..334 'A::foo': fn foo<i32>(&A<i32>) -> &i32
+    328..349 'A::foo...42))))': &i32
+    335..348 '&&B(B(A(42)))': &&B<B<A<i32>>>
+    336..348 '&B(B(A(42)))': &B<B<A<i32>>>
+    337..338 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
+    337..348 'B(B(A(42)))': B<B<A<i32>>>
+    339..340 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
+    339..347 'B(A(42))': B<A<i32>>
+    341..342 'A': A<i32>(i32) -> A<i32>
+    341..346 'A(42)': A<i32>
+    343..345 '42': i32
     "###
     );
 }
@@ -906,34 +915,34 @@ fn test(a: A<i32>) {
 }
 "#),
         @r###"
-    68..72 'self': &Self
-    144..148 'self': &A<T>
-    150..151 'x': &A<T>
-    166..187 '{     ...     }': &T
-    176..181 '&*x.0': &T
-    177..181 '*x.0': T
-    178..179 'x': &A<T>
-    178..181 'x.0': *mut T
-    268..272 'self': &B<T>
-    291..314 '{     ...     }': &T
-    301..308 '&self.0': &T
-    302..306 'self': &B<T>
-    302..308 'self.0': T
-    326..327 'a': A<i32>
-    337..383 '{     ...))); }': ()
-    347..348 't': &i32
-    351..352 'A': A<i32>(*mut i32) -> A<i32>
-    351..365 'A(0 as *mut _)': A<i32>
-    351..380 'A(0 as...B(a)))': &i32
-    353..354 '0': i32
-    353..364 '0 as *mut _': *mut i32
-    370..379 '&&B(B(a))': &&B<B<A<i32>>>
-    371..379 '&B(B(a))': &B<B<A<i32>>>
-    372..373 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
-    372..379 'B(B(a))': B<B<A<i32>>>
-    374..375 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
-    374..378 'B(a)': B<A<i32>>
-    376..377 'a': A<i32>
+    67..71 'self': &Self
+    143..147 'self': &A<T>
+    149..150 'x': &A<T>
+    165..186 '{     ...     }': &T
+    175..180 '&*x.0': &T
+    176..180 '*x.0': T
+    177..178 'x': &A<T>
+    177..180 'x.0': *mut T
+    267..271 'self': &B<T>
+    290..313 '{     ...     }': &T
+    300..307 '&self.0': &T
+    301..305 'self': &B<T>
+    301..307 'self.0': T
+    325..326 'a': A<i32>
+    336..382 '{     ...))); }': ()
+    346..347 't': &i32
+    350..351 'A': A<i32>(*mut i32) -> A<i32>
+    350..364 'A(0 as *mut _)': A<i32>
+    350..379 'A(0 as...B(a)))': &i32
+    352..353 '0': i32
+    352..363 '0 as *mut _': *mut i32
+    369..378 '&&B(B(a))': &&B<B<A<i32>>>
+    370..378 '&B(B(a))': &B<B<A<i32>>>
+    371..372 'B': B<B<A<i32>>>(B<A<i32>>) -> B<B<A<i32>>>
+    371..378 'B(B(a))': B<B<A<i32>>>
+    373..374 'B': B<A<i32>>(A<i32>) -> B<A<i32>>
+    373..377 'B(a)': B<A<i32>>
+    375..376 'a': A<i32>
     "###
     );
 }
@@ -952,16 +961,16 @@ fn main(foo: Foo) {
 }
 "#),
         @r###"
-    35..38 'foo': Foo
-    45..109 '{     ...   } }': ()
-    51..107 'if tru...     }': ()
-    54..58 'true': bool
-    59..67 '{      }': ()
-    73..107 'if fal...     }': i32
-    76..81 'false': bool
-    82..107 '{     ...     }': i32
-    92..95 'foo': Foo
-    92..101 'foo.field': i32
+    34..37 'foo': Foo
+    44..108 '{     ...   } }': ()
+    50..106 'if tru...     }': ()
+    53..57 'true': bool
+    58..66 '{      }': ()
+    72..106 'if fal...     }': i32
+    75..80 'false': bool
+    81..106 '{     ...     }': i32
+    91..94 'foo': Foo
+    91..100 'foo.field': i32
     "###
     )
 }
@@ -993,38 +1002,38 @@ fn foo() {
     };
 }"#),
         @r###"
-    10..323 '{     ...  }; }': ()
-    20..23 '_x1': i32
-    26..80 'if tru...     }': i32
-    29..33 'true': bool
-    34..51 '{     ...     }': i32
-    44..45 '1': i32
-    57..80 '{     ...     }': i32
-    67..73 'return': !
-    90..93 '_x2': i32
-    96..149 'if tru...     }': i32
-    99..103 'true': bool
-    104..121 '{     ...     }': i32
-    114..115 '2': i32
-    127..149 '{     ...     }': !
-    137..143 'return': !
-    159..162 '_x3': i32
-    165..247 'match ...     }': i32
-    171..175 'true': bool
-    186..190 'true': bool
-    186..190 'true': bool
-    194..195 '3': i32
-    205..206 '_': bool
-    210..241 '{     ...     }': i32
-    224..230 'return': !
-    257..260 '_x4': i32
-    263..320 'match ...     }': i32
-    269..273 'true': bool
-    284..288 'true': bool
-    284..288 'true': bool
-    292..293 '4': i32
-    303..304 '_': bool
-    308..314 'return': !
+    9..322 '{     ...  }; }': ()
+    19..22 '_x1': i32
+    25..79 'if tru...     }': i32
+    28..32 'true': bool
+    33..50 '{     ...     }': i32
+    43..44 '1': i32
+    56..79 '{     ...     }': i32
+    66..72 'return': !
+    89..92 '_x2': i32
+    95..148 'if tru...     }': i32
+    98..102 'true': bool
+    103..120 '{     ...     }': i32
+    113..114 '2': i32
+    126..148 '{     ...     }': !
+    136..142 'return': !
+    158..161 '_x3': i32
+    164..246 'match ...     }': i32
+    170..174 'true': bool
+    185..189 'true': bool
+    185..189 'true': bool
+    193..194 '3': i32
+    204..205 '_': bool
+    209..240 '{     ...     }': i32
+    223..229 'return': !
+    256..259 '_x4': i32
+    262..319 'match ...     }': i32
+    268..272 'true': bool
+    283..287 'true': bool
+    283..287 'true': bool
+    291..292 '4': i32
+    302..303 '_': bool
+    307..313 'return': !
     "###
     )
 }
@@ -1052,24 +1061,24 @@ fn test(a: A) {
 }
 "#),
         @r###"
-    32..36 'self': A
-    38..39 'x': u32
-    53..55 '{}': ()
-    103..107 'self': &A
-    109..110 'x': u64
-    124..126 '{}': ()
-    144..145 'a': A
-    150..198 '{     ...(1); }': ()
-    156..157 'a': A
-    156..164 'a.foo(1)': i32
-    162..163 '1': u32
-    170..181 '(&a).bar(1)': i64
-    171..173 '&a': &A
-    172..173 'a': A
-    179..180 '1': u64
-    187..188 'a': A
-    187..195 'a.bar(1)': i64
-    193..194 '1': u64
+    31..35 'self': A
+    37..38 'x': u32
+    52..54 '{}': ()
+    102..106 'self': &A
+    108..109 'x': u64
+    123..125 '{}': ()
+    143..144 'a': A
+    149..197 '{     ...(1); }': ()
+    155..156 'a': A
+    155..163 'a.foo(1)': i32
+    161..162 '1': u32
+    169..180 '(&a).bar(1)': i64
+    170..172 '&a': &A
+    171..172 'a': A
+    178..179 '1': u64
+    186..187 'a': A
+    186..194 'a.bar(1)': i64
+    192..193 '1': u64
     "###
     );
 }
@@ -1088,11 +1097,11 @@ fn test() {
 }
 "#),
         @r###"
-    40..44 'self': &str
-    53..55 '{}': ()
-    69..89 '{     ...o(); }': ()
-    75..80 '"foo"': &str
-    75..86 '"foo".foo()': i32
+    39..43 'self': &str
+    52..54 '{}': ()
+    68..88 '{     ...o(); }': ()
+    74..79 '"foo"': &str
+    74..85 '"foo".foo()': i32
     "###
     );
 }
@@ -1111,33 +1120,33 @@ fn test(x: &str, y: isize) {
 }
 "#),
         @r###"
-    9..10 'x': &str
-    18..19 'y': isize
-    28..170 '{     ...d"); }': ()
-    38..39 'a': (u32, &str)
-    55..63 '(1, "a")': (u32, &str)
-    56..57 '1': u32
-    59..62 '"a"': &str
-    73..74 'b': ((u32, &str), &str)
-    77..83 '(a, x)': ((u32, &str), &str)
-    78..79 'a': (u32, &str)
-    81..82 'x': &str
-    93..94 'c': (isize, &str)
-    97..103 '(y, x)': (isize, &str)
-    98..99 'y': isize
-    101..102 'x': &str
-    113..114 'd': ((isize, &str), &str)
-    117..123 '(c, x)': ((isize, &str), &str)
-    118..119 'c': (isize, &str)
-    121..122 'x': &str
-    133..134 'e': (i32, &str)
-    137..145 '(1, "e")': (i32, &str)
-    138..139 '1': i32
-    141..144 '"e"': &str
-    155..156 'f': ((i32, &str), &str)
-    159..167 '(e, "d")': ((i32, &str), &str)
-    160..161 'e': (i32, &str)
-    163..166 '"d"': &str
+    8..9 'x': &str
+    17..18 'y': isize
+    27..169 '{     ...d"); }': ()
+    37..38 'a': (u32, &str)
+    54..62 '(1, "a")': (u32, &str)
+    55..56 '1': u32
+    58..61 '"a"': &str
+    72..73 'b': ((u32, &str), &str)
+    76..82 '(a, x)': ((u32, &str), &str)
+    77..78 'a': (u32, &str)
+    80..81 'x': &str
+    92..93 'c': (isize, &str)
+    96..102 '(y, x)': (isize, &str)
+    97..98 'y': isize
+    100..101 'x': &str
+    112..113 'd': ((isize, &str), &str)
+    116..122 '(c, x)': ((isize, &str), &str)
+    117..118 'c': (isize, &str)
+    120..121 'x': &str
+    132..133 'e': (i32, &str)
+    136..144 '(1, "e")': (i32, &str)
+    137..138 '1': i32
+    140..143 '"e"': &str
+    154..155 'f': ((i32, &str), &str)
+    158..166 '(e, "d")': ((i32, &str), &str)
+    159..160 'e': (i32, &str)
+    162..165 '"d"': &str
     "###
     );
 }
@@ -1165,58 +1174,58 @@ fn test(x: &str, y: isize) {
 }
 "#),
         @r###"
-    9..10 'x': &str
-    18..19 'y': isize
-    28..293 '{     ... []; }': ()
-    38..39 'a': [&str; _]
-    42..45 '[x]': [&str; _]
-    43..44 'x': &str
-    55..56 'b': [[&str; _]; _]
-    59..65 '[a, a]': [[&str; _]; _]
-    60..61 'a': [&str; _]
-    63..64 'a': [&str; _]
-    75..76 'c': [[[&str; _]; _]; _]
-    79..85 '[b, b]': [[[&str; _]; _]; _]
-    80..81 'b': [[&str; _]; _]
-    83..84 'b': [[&str; _]; _]
-    96..97 'd': [isize; _]
-    100..112 '[y, 1, 2, 3]': [isize; _]
-    101..102 'y': isize
-    104..105 '1': isize
-    107..108 '2': isize
-    110..111 '3': isize
-    122..123 'd': [isize; _]
-    126..138 '[1, y, 2, 3]': [isize; _]
-    127..128 '1': isize
-    130..131 'y': isize
-    133..134 '2': isize
-    136..137 '3': isize
-    148..149 'e': [isize; _]
-    152..155 '[y]': [isize; _]
-    153..154 'y': isize
-    165..166 'f': [[isize; _]; _]
-    169..175 '[d, d]': [[isize; _]; _]
-    170..171 'd': [isize; _]
-    173..174 'd': [isize; _]
-    185..186 'g': [[isize; _]; _]
-    189..195 '[e, e]': [[isize; _]; _]
-    190..191 'e': [isize; _]
-    193..194 'e': [isize; _]
-    206..207 'h': [i32; _]
-    210..216 '[1, 2]': [i32; _]
-    211..212 '1': i32
-    214..215 '2': i32
-    226..227 'i': [&str; _]
-    230..240 '["a", "b"]': [&str; _]
-    231..234 '"a"': &str
-    236..239 '"b"': &str
-    251..252 'b': [[&str; _]; _]
-    255..265 '[a, ["b"]]': [[&str; _]; _]
-    256..257 'a': [&str; _]
-    259..264 '["b"]': [&str; _]
-    260..263 '"b"': &str
-    275..276 'x': [u8; _]
-    288..290 '[]': [u8; _]
+    8..9 'x': &str
+    17..18 'y': isize
+    27..292 '{     ... []; }': ()
+    37..38 'a': [&str; _]
+    41..44 '[x]': [&str; _]
+    42..43 'x': &str
+    54..55 'b': [[&str; _]; _]
+    58..64 '[a, a]': [[&str; _]; _]
+    59..60 'a': [&str; _]
+    62..63 'a': [&str; _]
+    74..75 'c': [[[&str; _]; _]; _]
+    78..84 '[b, b]': [[[&str; _]; _]; _]
+    79..80 'b': [[&str; _]; _]
+    82..83 'b': [[&str; _]; _]
+    95..96 'd': [isize; _]
+    99..111 '[y, 1, 2, 3]': [isize; _]
+    100..101 'y': isize
+    103..104 '1': isize
+    106..107 '2': isize
+    109..110 '3': isize
+    121..122 'd': [isize; _]
+    125..137 '[1, y, 2, 3]': [isize; _]
+    126..127 '1': isize
+    129..130 'y': isize
+    132..133 '2': isize
+    135..136 '3': isize
+    147..148 'e': [isize; _]
+    151..154 '[y]': [isize; _]
+    152..153 'y': isize
+    164..165 'f': [[isize; _]; _]
+    168..174 '[d, d]': [[isize; _]; _]
+    169..170 'd': [isize; _]
+    172..173 'd': [isize; _]
+    184..185 'g': [[isize; _]; _]
+    188..194 '[e, e]': [[isize; _]; _]
+    189..190 'e': [isize; _]
+    192..193 'e': [isize; _]
+    205..206 'h': [i32; _]
+    209..215 '[1, 2]': [i32; _]
+    210..211 '1': i32
+    213..214 '2': i32
+    225..226 'i': [&str; _]
+    229..239 '["a", "b"]': [&str; _]
+    230..233 '"a"': &str
+    235..238 '"b"': &str
+    250..251 'b': [[&str; _]; _]
+    254..264 '[a, ["b"]]': [[&str; _]; _]
+    255..256 'a': [&str; _]
+    258..263 '["b"]': [&str; _]
+    259..262 '"b"': &str
+    274..275 'x': [u8; _]
+    287..289 '[]': [u8; _]
     "###
     );
 }
@@ -1238,21 +1247,21 @@ fn test(a1: A<u32>, i: i32) {
 }
 "#),
         @r###"
-    36..38 'a1': A<u32>
-    48..49 'i': i32
-    56..147 '{     ...3.x; }': ()
-    62..64 'a1': A<u32>
-    62..66 'a1.x': u32
-    76..78 'a2': A<i32>
-    81..91 'A { x: i }': A<i32>
-    88..89 'i': i32
-    97..99 'a2': A<i32>
-    97..101 'a2.x': i32
-    111..113 'a3': A<i128>
-    116..134 'A::<i1...x: 1 }': A<i128>
-    131..132 '1': i128
-    140..142 'a3': A<i128>
-    140..144 'a3.x': i128
+    35..37 'a1': A<u32>
+    47..48 'i': i32
+    55..146 '{     ...3.x; }': ()
+    61..63 'a1': A<u32>
+    61..65 'a1.x': u32
+    75..77 'a2': A<i32>
+    80..90 'A { x: i }': A<i32>
+    87..88 'i': i32
+    96..98 'a2': A<i32>
+    96..100 'a2.x': i32
+    110..112 'a3': A<i128>
+    115..133 'A::<i1...x: 1 }': A<i128>
+    130..131 '1': i128
+    139..141 'a3': A<i128>
+    139..143 'a3.x': i128
     "###
     );
 }
@@ -1275,22 +1284,22 @@ fn test() {
 }
 "#),
         @r###"
-    76..184 '{     ...one; }': ()
-    82..83 'A': A<i32>(i32) -> A<i32>
-    82..87 'A(42)': A<i32>
-    84..86 '42': i32
-    93..94 'A': A<u128>(u128) -> A<u128>
-    93..102 'A(42u128)': A<u128>
-    95..101 '42u128': u128
-    108..112 'Some': Some<&str>(&str) -> Option<&str>
-    108..117 'Some("x")': Option<&str>
-    113..116 '"x"': &str
-    123..135 'Option::Some': Some<&str>(&str) -> Option<&str>
-    123..140 'Option...e("x")': Option<&str>
-    136..139 '"x"': &str
-    146..150 'None': Option<{unknown}>
-    160..161 'x': Option<i64>
-    177..181 'None': Option<i64>
+    75..183 '{     ...one; }': ()
+    81..82 'A': A<i32>(i32) -> A<i32>
+    81..86 'A(42)': A<i32>
+    83..85 '42': i32
+    92..93 'A': A<u128>(u128) -> A<u128>
+    92..101 'A(42u128)': A<u128>
+    94..100 '42u128': u128
+    107..111 'Some': Some<&str>(&str) -> Option<&str>
+    107..116 'Some("x")': Option<&str>
+    112..115 '"x"': &str
+    122..134 'Option::Some': Some<&str>(&str) -> Option<&str>
+    122..139 'Option...e("x")': Option<&str>
+    135..138 '"x"': &str
+    145..149 'None': Option<{unknown}>
+    159..160 'x': Option<i64>
+    176..180 'None': Option<i64>
     "###
     );
 }
@@ -1308,20 +1317,20 @@ fn test() {
 }
 "#),
         @r###"
-    10..11 't': T
-    21..26 '{ t }': T
-    23..24 't': T
-    38..98 '{     ...(1); }': ()
-    44..46 'id': fn id<u32>(u32) -> u32
-    44..52 'id(1u32)': u32
-    47..51 '1u32': u32
-    58..68 'id::<i128>': fn id<i128>(i128) -> i128
-    58..71 'id::<i128>(1)': i128
-    69..70 '1': i128
-    81..82 'x': u64
-    90..92 'id': fn id<u64>(u64) -> u64
-    90..95 'id(1)': u64
-    93..94 '1': u64
+    9..10 't': T
+    20..25 '{ t }': T
+    22..23 't': T
+    37..97 '{     ...(1); }': ()
+    43..45 'id': fn id<u32>(u32) -> u32
+    43..51 'id(1u32)': u32
+    46..50 '1u32': u32
+    57..67 'id::<i128>': fn id<i128>(i128) -> i128
+    57..70 'id::<i128>(1)': i128
+    68..69 '1': i128
+    80..81 'x': u64
+    89..91 'id': fn id<u64>(u64) -> u64
+    89..94 'id(1)': u64
+    92..93 '1': u64
     "###
     );
 }
@@ -1355,38 +1364,38 @@ fn test() -> i128 {
 }
 "#),
         @r###"
-    74..78 'self': A<X, Y>
-    85..107 '{     ...     }': X
-    95..99 'self': A<X, Y>
-    95..101 'self.x': X
-    117..121 'self': A<X, Y>
-    128..150 '{     ...     }': Y
-    138..142 'self': A<X, Y>
-    138..144 'self.y': Y
-    163..167 'self': A<X, Y>
-    169..170 't': T
-    188..223 '{     ...     }': (X, Y, T)
-    198..217 '(self.....y, t)': (X, Y, T)
-    199..203 'self': A<X, Y>
-    199..205 'self.x': X
-    207..211 'self': A<X, Y>
-    207..213 'self.y': Y
-    215..216 't': T
-    245..342 '{     ...(1); }': ()
-    255..256 'a': A<u64, i64>
-    259..281 'A { x:...1i64 }': A<u64, i64>
-    266..270 '1u64': u64
-    275..279 '1i64': i64
-    287..288 'a': A<u64, i64>
-    287..292 'a.x()': u64
-    298..299 'a': A<u64, i64>
-    298..303 'a.y()': i64
-    309..310 'a': A<u64, i64>
-    309..319 'a.z(1i128)': (u64, i64, i128)
-    313..318 '1i128': i128
-    325..326 'a': A<u64, i64>
-    325..339 'a.z::<u128>(1)': (u64, i64, u128)
-    337..338 '1': u128
+    73..77 'self': A<X, Y>
+    84..106 '{     ...     }': X
+    94..98 'self': A<X, Y>
+    94..100 'self.x': X
+    116..120 'self': A<X, Y>
+    127..149 '{     ...     }': Y
+    137..141 'self': A<X, Y>
+    137..143 'self.y': Y
+    162..166 'self': A<X, Y>
+    168..169 't': T
+    187..222 '{     ...     }': (X, Y, T)
+    197..216 '(self.....y, t)': (X, Y, T)
+    198..202 'self': A<X, Y>
+    198..204 'self.x': X
+    206..210 'self': A<X, Y>
+    206..212 'self.y': Y
+    214..215 't': T
+    244..341 '{     ...(1); }': ()
+    254..255 'a': A<u64, i64>
+    258..280 'A { x:...1i64 }': A<u64, i64>
+    265..269 '1u64': u64
+    274..278 '1i64': i64
+    286..287 'a': A<u64, i64>
+    286..291 'a.x()': u64
+    297..298 'a': A<u64, i64>
+    297..302 'a.y()': i64
+    308..309 'a': A<u64, i64>
+    308..318 'a.z(1i128)': (u64, i64, i128)
+    312..317 '1i128': i128
+    324..325 'a': A<u64, i64>
+    324..338 'a.z::<u128>(1)': (u64, i64, u128)
+    336..337 '1': u128
     "###
     );
 }
@@ -1408,15 +1417,15 @@ fn test(o: Option<u32>) {
 }
 "#),
         @r###"
-    78..82 'self': &Option<T>
-    98..100 '{}': ()
-    111..112 'o': Option<u32>
-    127..165 '{     ...f(); }': ()
-    133..146 '(&o).as_ref()': Option<&u32>
-    134..136 '&o': &Option<u32>
-    135..136 'o': Option<u32>
-    152..153 'o': Option<u32>
-    152..162 'o.as_ref()': Option<&u32>
+    77..81 'self': &Option<T>
+    97..99 '{}': ()
+    110..111 'o': Option<u32>
+    126..164 '{     ...f(); }': ()
+    132..145 '(&o).as_ref()': Option<&u32>
+    133..135 '&o': &Option<u32>
+    134..135 'o': Option<u32>
+    151..152 'o': Option<u32>
+    151..161 'o.as_ref()': Option<&u32>
     "###
     );
 }
@@ -1445,35 +1454,35 @@ fn test() -> i128 {
 }
 "#),
         @r###"
-    53..57 'self': A<T2>
-    65..87 '{     ...     }': T2
-    75..79 'self': A<T2>
-    75..81 'self.x': T2
-    99..100 't': T
-    110..115 '{ t }': T
-    112..113 't': T
-    135..261 '{     ....x() }': i128
-    146..147 'x': i128
-    150..151 '1': i128
-    162..163 'y': i128
-    166..168 'id': fn id<i128>(i128) -> i128
-    166..171 'id(x)': i128
-    169..170 'x': i128
-    182..183 'a': A<i128>
-    186..200 'A { x: id(y) }': A<i128>
-    193..195 'id': fn id<i128>(i128) -> i128
-    193..198 'id(y)': i128
-    196..197 'y': i128
-    211..212 'z': i128
-    215..217 'id': fn id<i128>(i128) -> i128
-    215..222 'id(a.x)': i128
-    218..219 'a': A<i128>
-    218..221 'a.x': i128
-    233..234 'b': A<i128>
-    237..247 'A { x: z }': A<i128>
-    244..245 'z': i128
-    254..255 'b': A<i128>
-    254..259 'b.x()': i128
+    52..56 'self': A<T2>
+    64..86 '{     ...     }': T2
+    74..78 'self': A<T2>
+    74..80 'self.x': T2
+    98..99 't': T
+    109..114 '{ t }': T
+    111..112 't': T
+    134..260 '{     ....x() }': i128
+    145..146 'x': i128
+    149..150 '1': i128
+    161..162 'y': i128
+    165..167 'id': fn id<i128>(i128) -> i128
+    165..170 'id(x)': i128
+    168..169 'x': i128
+    181..182 'a': A<i128>
+    185..199 'A { x: id(y) }': A<i128>
+    192..194 'id': fn id<i128>(i128) -> i128
+    192..197 'id(y)': i128
+    195..196 'y': i128
+    210..211 'z': i128
+    214..216 'id': fn id<i128>(i128) -> i128
+    214..221 'id(a.x)': i128
+    217..218 'a': A<i128>
+    217..220 'a.x': i128
+    232..233 'b': A<i128>
+    236..246 'A { x: z }': A<i128>
+    243..244 'z': i128
+    253..254 'b': A<i128>
+    253..258 'b.x()': i128
     "###
     );
 }
@@ -1511,16 +1520,16 @@ fn test() {
 }
 "#),
         @r###"
-    52..53 '1': u32
-    105..106 '2': u32
-    213..214 '5': u32
-    229..307 '{     ...:ID; }': ()
-    239..240 'x': u32
-    243..254 'Struct::FOO': u32
-    264..265 'y': u32
-    268..277 'Enum::BAR': u32
-    287..288 'z': u32
-    291..304 'TraitTest::ID': u32
+    51..52 '1': u32
+    104..105 '2': u32
+    212..213 '5': u32
+    228..306 '{     ...:ID; }': ()
+    238..239 'x': u32
+    242..253 'Struct::FOO': u32
+    263..264 'y': u32
+    267..276 'Enum::BAR': u32
+    286..287 'z': u32
+    290..303 'TraitTest::ID': u32
     "###
     );
 }
@@ -1543,22 +1552,22 @@ fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
 }
 "#),
         @r###"
-    116..117 'x': A<u32, i128>
-    124..125 'y': A<&str, u128>
-    138..139 'z': A<u8, i8>
-    154..211 '{     ...z.y; }': ()
-    160..161 'x': A<u32, i128>
-    160..163 'x.x': u32
-    169..170 'x': A<u32, i128>
-    169..172 'x.y': i128
-    178..179 'y': A<&str, u128>
-    178..181 'y.x': &str
-    187..188 'y': A<&str, u128>
-    187..190 'y.y': u128
-    196..197 'z': A<u8, i8>
-    196..199 'z.x': u8
-    205..206 'z': A<u8, i8>
-    205..208 'z.y': i8
+    115..116 'x': A<u32, i128>
+    123..124 'y': A<&str, u128>
+    137..138 'z': A<u8, i8>
+    153..210 '{     ...z.y; }': ()
+    159..160 'x': A<u32, i128>
+    159..162 'x.x': u32
+    168..169 'x': A<u32, i128>
+    168..171 'x.y': i128
+    177..178 'y': A<&str, u128>
+    177..180 'y.x': &str
+    186..187 'y': A<&str, u128>
+    186..189 'y.y': u128
+    195..196 'z': A<u8, i8>
+    195..198 'z.x': u8
+    204..205 'z': A<u8, i8>
+    204..207 'z.y': i8
     "###
     )
 }
@@ -1573,8 +1582,8 @@ type Bar = A<Bar>;
 fn test(x: Foo) {}
 "#),
         @r###"
-    59..60 'x': {unknown}
-    67..69 '{}': ()
+    58..59 'x': {unknown}
+    66..68 '{}': ()
     "###
     )
 }
@@ -1599,26 +1608,26 @@ fn test() {
 }
 "#),
         @r###"
-    10..11 'x': T
-    21..30 '{     x }': T
-    27..28 'x': T
-    44..45 'x': &T
-    56..66 '{     *x }': T
-    62..64 '*x': T
-    63..64 'x': &T
-    78..158 '{     ...(1); }': ()
-    88..89 'y': u32
-    92..97 '10u32': u32
-    103..105 'id': fn id<u32>(u32) -> u32
-    103..108 'id(y)': u32
-    106..107 'y': u32
-    118..119 'x': bool
-    128..133 'clone': fn clone<bool>(&bool) -> bool
-    128..136 'clone(z)': bool
-    134..135 'z': &bool
-    142..152 'id::<i128>': fn id<i128>(i128) -> i128
-    142..155 'id::<i128>(1)': i128
-    153..154 '1': i128
+    9..10 'x': T
+    20..29 '{     x }': T
+    26..27 'x': T
+    43..44 'x': &T
+    55..65 '{     *x }': T
+    61..63 '*x': T
+    62..63 'x': &T
+    77..157 '{     ...(1); }': ()
+    87..88 'y': u32
+    91..96 '10u32': u32
+    102..104 'id': fn id<u32>(u32) -> u32
+    102..107 'id(y)': u32
+    105..106 'y': u32
+    117..118 'x': bool
+    127..132 'clone': fn clone<bool>(&bool) -> bool
+    127..135 'clone(z)': bool
+    133..134 'z': &bool
+    141..151 'id::<i128>': fn id<i128>(i128) -> i128
+    141..154 'id::<i128>(1)': i128
+    152..153 '1': i128
     "###
     );
 }
@@ -1638,16 +1647,16 @@ fn test() {
 }
 "#),
         @r###"
-    49..50 '0': u32
-    80..83 '101': u32
-    95..213 '{     ...NST; }': ()
-    138..139 'x': u32
-    142..153 'LOCAL_CONST': u32
-    163..164 'z': u32
-    167..179 'GLOBAL_CONST': u32
-    189..191 'id': u32
-    194..210 'Foo::A..._CONST': u32
-    126..128 '99': u32
+    48..49 '0': u32
+    79..82 '101': u32
+    94..212 '{     ...NST; }': ()
+    137..138 'x': u32
+    141..152 'LOCAL_CONST': u32
+    162..163 'z': u32
+    166..178 'GLOBAL_CONST': u32
+    188..190 'id': u32
+    193..209 'Foo::A..._CONST': u32
+    125..127 '99': u32
     "###
     );
 }
@@ -1668,28 +1677,27 @@ fn test() {
 }
 "#),
         @r###"
-    29..32 '101': u32
-    70..73 '101': u32
-    85..280 '{     ...MUT; }': ()
-    173..174 'x': u32
-    177..189 'LOCAL_STATIC': u32
-    199..200 'y': u32
-    203..219 'LOCAL_...IC_MUT': u32
-    229..230 'z': u32
-    233..246 'GLOBAL_STATIC': u32
-    256..257 'w': u32
-    260..277 'GLOBAL...IC_MUT': u32
-    118..120 '99': u32
-    161..163 '99': u32
+    28..31 '101': u32
+    69..72 '101': u32
+    84..279 '{     ...MUT; }': ()
+    172..173 'x': u32
+    176..188 'LOCAL_STATIC': u32
+    198..199 'y': u32
+    202..218 'LOCAL_...IC_MUT': u32
+    228..229 'z': u32
+    232..245 'GLOBAL_STATIC': u32
+    255..256 'w': u32
+    259..276 'GLOBAL...IC_MUT': u32
+    117..119 '99': u32
+    160..162 '99': u32
     "###
     );
 }
 
 #[test]
 fn shadowing_primitive() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct i32;
 struct Foo;
 
@@ -1697,15 +1705,15 @@ impl i32 { fn foo(&self) -> Foo { Foo } }
 
 fn main() {
     let x: i32 = i32;
-    x.foo()<|>;
+    x.foo();
+        //^ Foo
 }"#,
     );
-    assert_eq!(t, "Foo");
 }
 
 #[test]
 fn not_shadowing_primitive_by_module() {
-    let t = type_at(
+    check_types(
         r#"
 //- /str.rs
 fn foo() {}
@@ -1715,15 +1723,15 @@ mod str;
 fn foo() -> &'static str { "" }
 
 fn main() {
-    foo()<|>;
+    foo();
+      //^ &str
 }"#,
     );
-    assert_eq!(t, "&str");
 }
 
 #[test]
 fn not_shadowing_module_by_primitive() {
-    let t = type_at(
+    check_types(
         r#"
 //- /str.rs
 fn foo() -> u32 {0}
@@ -1733,10 +1741,38 @@ mod str;
 fn foo() -> &'static str { "" }
 
 fn main() {
-    str::foo()<|>;
+    str::foo();
+           //^ u32
+}"#,
+    );
+}
+
+// This test is actually testing the shadowing behavior within ra_hir_def. It
+// lives here because the testing infrastructure in ra_hir_def isn't currently
+// capable of asserting the necessary conditions.
+#[test]
+fn should_be_shadowing_imports() {
+    check_types(
+        r#"
+mod a {
+    pub fn foo() -> i8 {0}
+    pub struct foo { a: i8 }
+}
+mod b { pub fn foo () -> u8 {0} }
+mod c { pub struct foo { a: u8 } }
+mod d {
+    pub use super::a::*;
+    pub use super::c::foo;
+    pub use super::b::foo;
+}
+
+fn main() {
+    d::foo();
+         //^ u8
+    d::foo{a:0};
+           //^ u8
 }"#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
@@ -1748,12 +1784,12 @@ fn foo() -> u32 {
 }
 "#),
         @r###"
-    17..59 '{     ...; }; }': ()
-    27..28 'x': || -> usize
-    31..56 '|| -> ...n 1; }': || -> usize
-    43..56 '{ return 1; }': usize
-    45..53 'return 1': !
-    52..53 '1': usize
+    16..58 '{     ...; }; }': ()
+    26..27 'x': || -> usize
+    30..55 '|| -> ...n 1; }': || -> usize
+    42..55 '{ return 1; }': usize
+    44..52 'return 1': !
+    51..52 '1': usize
     "###
     );
 }
@@ -1767,11 +1803,11 @@ fn foo() -> u32 {
 }
 "#),
         @r###"
-    17..48 '{     ...; }; }': ()
-    27..28 'x': || -> ()
-    31..45 '|| { return; }': || -> ()
-    34..45 '{ return; }': ()
-    36..42 'return': !
+    16..47 '{     ...; }; }': ()
+    26..27 'x': || -> ()
+    30..44 '|| { return; }': || -> ()
+    33..44 '{ return; }': ()
+    35..41 'return': !
     "###
     );
 }
@@ -1785,11 +1821,11 @@ fn foo() -> u32 {
 }
 "#),
         @r###"
-    17..47 '{     ..." }; }': ()
-    27..28 'x': || -> &str
-    31..44 '|| { "test" }': || -> &str
-    34..44 '{ "test" }': &str
-    36..42 '"test"': &str
+    16..46 '{     ..." }; }': ()
+    26..27 'x': || -> &str
+    30..43 '|| { "test" }': || -> &str
+    33..43 '{ "test" }': &str
+    35..41 '"test"': &str
     "###
     );
 }
@@ -1808,14 +1844,14 @@ fn main() {
 }
 "#),
         @r###"
-    48..121 '{     ...hod; }': ()
-    58..64 'vtable': Vtable
-    67..91 'Vtable...| {} }': Vtable
-    84..89 '|| {}': || -> ()
-    87..89 '{}': ()
-    101..102 'm': fn()
-    105..111 'vtable': Vtable
-    105..118 'vtable.method': fn()
+    47..120 '{     ...hod; }': ()
+    57..63 'vtable': Vtable
+    66..90 'Vtable...| {} }': Vtable
+    83..88 '|| {}': || -> ()
+    86..88 '{}': ()
+    100..101 'm': fn()
+    104..110 'vtable': Vtable
+    104..117 'vtable.method': fn()
     "###
     );
 }
@@ -1832,22 +1868,23 @@ fn main() {
 }
 "#),
         @r###"
-    11..131 '{     ...2 }; }': ()
-    21..22 'x': i32
-    32..38 '{ 92 }': i32
-    34..36 '92': i32
-    48..49 'y': {unknown}
-    58..80 '{ asyn...wait }': {unknown}
-    60..78 'async ....await': {unknown}
-    66..72 '{ () }': ()
-    68..70 '()': ()
-    90..91 'z': {unknown}
-    94..104 'try { () }': {unknown}
-    98..104 '{ () }': ()
-    100..102 '()': ()
-    114..115 't': i32
-    122..128 '{ 92 }': i32
-    124..126 '92': i32
+    10..130 '{     ...2 }; }': ()
+    20..21 'x': i32
+    24..37 'unsafe { 92 }': i32
+    31..37 '{ 92 }': i32
+    33..35 '92': i32
+    47..48 'y': {unknown}
+    57..79 '{ asyn...wait }': {unknown}
+    59..77 'async ....await': {unknown}
+    65..71 '{ () }': ()
+    67..69 '()': ()
+    89..90 'z': {unknown}
+    93..103 'try { () }': {unknown}
+    97..103 '{ () }': ()
+    99..101 '()': ()
+    113..114 't': i32
+    121..127 '{ 92 }': i32
+    123..125 '92': i32
     "###
     )
 }
@@ -1867,16 +1904,16 @@ fn test() {
 }
 "#),
         @r###"
-    60..130 '{     ...   } }': ()
-    70..77 'mut end': Option<bool>
-    80..84 'None': Option<bool>
-    90..128 'loop {...     }': !
-    95..128 '{     ...     }': ()
-    105..108 'end': Option<bool>
-    105..121 'end = ...(true)': ()
-    111..115 'Some': Some<bool>(bool) -> Option<bool>
-    111..121 'Some(true)': Option<bool>
-    116..120 'true': bool
+    59..129 '{     ...   } }': ()
+    69..76 'mut end': Option<bool>
+    79..83 'None': Option<bool>
+    89..127 'loop {...     }': !
+    94..127 '{     ...     }': ()
+    104..107 'end': Option<bool>
+    104..120 'end = ...(true)': ()
+    110..114 'Some': Some<bool>(bool) -> Option<bool>
+    110..120 'Some(true)': Option<bool>
+    115..119 'true': bool
     "###
     );
 }
@@ -1899,19 +1936,19 @@ fn test() {
 }
 "#),
         @r###"
-    60..169 '{     ...  }; }': ()
-    70..71 'x': Option<bool>
-    74..166 'loop {...     }': Option<bool>
-    79..166 '{     ...     }': ()
-    89..133 'if fal...     }': ()
-    92..97 'false': bool
-    98..133 '{     ...     }': ()
-    112..122 'break None': !
-    118..122 'None': Option<bool>
-    143..159 'break ...(true)': !
-    149..153 'Some': Some<bool>(bool) -> Option<bool>
-    149..159 'Some(true)': Option<bool>
-    154..158 'true': bool
+    59..168 '{     ...  }; }': ()
+    69..70 'x': Option<bool>
+    73..165 'loop {...     }': Option<bool>
+    78..165 '{     ...     }': ()
+    88..132 'if fal...     }': ()
+    91..96 'false': bool
+    97..132 '{     ...     }': ()
+    111..121 'break None': !
+    117..121 'None': Option<bool>
+    142..158 'break ...(true)': !
+    148..152 'Some': Some<bool>(bool) -> Option<bool>
+    148..158 'Some(true)': Option<bool>
+    153..157 'true': bool
     "###
     );
 }
@@ -1932,14 +1969,14 @@ fn test() {
 }
 "#),
         @r###"
-    60..137 '{     ...  }; }': ()
-    70..71 'x': ()
-    74..134 'loop {...     }': ()
-    79..134 '{     ...     }': ()
-    89..128 'if fal...     }': ()
-    92..97 'false': bool
-    98..128 '{     ...     }': ()
-    112..117 'break': !
+    59..136 '{     ...  }; }': ()
+    69..70 'x': ()
+    73..133 'loop {...     }': ()
+    78..133 '{     ...     }': ()
+    88..127 'if fal...     }': ()
+    91..96 'false': bool
+    97..127 '{     ...     }': ()
+    111..116 'break': !
     "###
     );
 }
@@ -1964,36 +2001,189 @@ fn foo() {
 }
 "#),
         @r###"
-    10..336 '{     ...  }; }': ()
-    20..22 '_x': || -> bool
-    25..333 '|| 'ou...     }': || -> bool
-    28..333 ''outer...     }': bool
-    41..333 '{     ...     }': ()
-    55..60 'inner': i8
-    63..301 ''inner...     }': i8
-    76..301 '{     ...     }': ()
-    94..95 'i': bool
-    98..114 'Defaul...efault': {unknown}
-    98..116 'Defaul...ault()': bool
-    130..270 'if (br...     }': ()
-    134..148 'break 'outer i': !
-    147..148 'i': bool
-    150..209 '{     ...     }': ()
-    168..194 'loop {...5i8; }': !
-    173..194 '{ brea...5i8; }': ()
-    175..191 'break ...er 5i8': !
-    188..191 '5i8': i8
-    215..270 'if tru...     }': ()
-    218..222 'true': bool
-    223..270 '{     ...     }': ()
-    241..255 'break 'inner 6': !
-    254..255 '6': i8
-    283..290 'break 7': !
-    289..290 '7': i8
-    311..326 'break inner < 8': !
-    317..322 'inner': i8
-    317..326 'inner < 8': bool
-    325..326 '8': i8
+    9..335 '{     ...  }; }': ()
+    19..21 '_x': || -> bool
+    24..332 '|| 'ou...     }': || -> bool
+    27..332 ''outer...     }': bool
+    40..332 '{     ...     }': ()
+    54..59 'inner': i8
+    62..300 ''inner...     }': i8
+    75..300 '{     ...     }': ()
+    93..94 'i': bool
+    97..113 'Defaul...efault': {unknown}
+    97..115 'Defaul...ault()': bool
+    129..269 'if (br...     }': ()
+    133..147 'break 'outer i': !
+    146..147 'i': bool
+    149..208 '{     ...     }': ()
+    167..193 'loop {...5i8; }': !
+    172..193 '{ brea...5i8; }': ()
+    174..190 'break ...er 5i8': !
+    187..190 '5i8': i8
+    214..269 'if tru...     }': ()
+    217..221 'true': bool
+    222..269 '{     ...     }': ()
+    240..254 'break 'inner 6': !
+    253..254 '6': i8
+    282..289 'break 7': !
+    288..289 '7': i8
+    310..325 'break inner < 8': !
+    316..321 'inner': i8
+    316..325 'inner < 8': bool
+    324..325 '8': i8
+    "###
+    );
+}
+
+#[test]
+fn generic_default() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test(t1: Thing, t2: OtherThing, t3: Thing<i32>, t4: OtherThing<i32>) {
+    t1.t;
+    t3.t;
+    match t2 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+    match t4 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+}
+"#),
+        @r###"
+    97..99 't1': Thing<()>
+    108..110 't2': OtherThing<()>
+    124..126 't3': Thing<i32>
+    140..142 't4': OtherThing<i32>
+    161..384 '{     ...   } }': ()
+    167..169 't1': Thing<()>
+    167..171 't1.t': ()
+    177..179 't3': Thing<i32>
+    177..181 't3.t': i32
+    187..282 'match ...     }': ()
+    193..195 't2': OtherThing<()>
+    206..227 'OtherT... { t }': OtherThing<()>
+    224..225 't': ()
+    231..237 '{ t; }': ()
+    233..234 't': ()
+    247..265 'OtherT...Two(t)': OtherThing<()>
+    263..264 't': ()
+    269..275 '{ t; }': ()
+    271..272 't': ()
+    287..382 'match ...     }': ()
+    293..295 't4': OtherThing<i32>
+    306..327 'OtherT... { t }': OtherThing<i32>
+    324..325 't': i32
+    331..337 '{ t; }': ()
+    333..334 't': i32
+    347..365 'OtherT...Two(t)': OtherThing<i32>
+    363..364 't': i32
+    369..375 '{ t; }': ()
+    371..372 't': i32
+    "###
+    );
+}
+
+#[test]
+fn generic_default_in_struct_literal() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test() {
+    let x = Thing { t: loop {} };
+    let y = Thing { t: () };
+    let z = Thing { t: 1i32 };
+    if let Thing { t } = z {
+        t;
+    }
+
+    let a = OtherThing::One { t: 1i32 };
+    let b = OtherThing::Two(1i32);
+}
+"#),
+        @r###"
+    99..319 '{     ...32); }': ()
+    109..110 'x': Thing<!>
+    113..133 'Thing ...p {} }': Thing<!>
+    124..131 'loop {}': !
+    129..131 '{}': ()
+    143..144 'y': Thing<()>
+    147..162 'Thing { t: () }': Thing<()>
+    158..160 '()': ()
+    172..173 'z': Thing<i32>
+    176..193 'Thing ...1i32 }': Thing<i32>
+    187..191 '1i32': i32
+    199..240 'if let...     }': ()
+    206..217 'Thing { t }': Thing<i32>
+    214..215 't': i32
+    220..221 'z': Thing<i32>
+    222..240 '{     ...     }': ()
+    232..233 't': i32
+    250..251 'a': OtherThing<i32>
+    254..281 'OtherT...1i32 }': OtherThing<i32>
+    275..279 '1i32': i32
+    291..292 'b': OtherThing<i32>
+    295..310 'OtherThing::Two': Two<i32>(i32) -> OtherThing<i32>
+    295..316 'OtherT...(1i32)': OtherThing<i32>
+    311..315 '1i32': i32
+    "###
+    );
+}
+
+#[test]
+fn generic_default_depending_on_other_type_arg() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = u128, F = fn() -> T> { t: T }
+
+fn test(t1: Thing<u32>, t2: Thing) {
+    t1;
+    t2;
+    Thing::<_> { t: 1u32 };
+}
+"#),
+        // FIXME: the {unknown} is a bug
+        @r###"
+    56..58 't1': Thing<u32, fn() -> u32>
+    72..74 't2': Thing<u128, fn() -> u128>
+    83..130 '{     ...2 }; }': ()
+    89..91 't1': Thing<u32, fn() -> u32>
+    97..99 't2': Thing<u128, fn() -> u128>
+    105..127 'Thing:...1u32 }': Thing<u32, fn() -> {unknown}>
+    121..125 '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn generic_default_depending_on_other_type_arg_forward() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<F = fn() -> T, T = u128> { t: T }
+
+fn test(t1: Thing) {
+    t1;
+}
+"#),
+        // the {unknown} here is intentional, as defaults are not allowed to
+        // refer to type parameters coming later
+        @r###"
+    56..58 't1': Thing<fn() -> {unknown}, u128>
+    67..78 '{     t1; }': ()
+    73..75 't1': Thing<fn() -> {unknown}, u128>
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index e8778d419..27737fa94 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -1,17 +1,13 @@
 use insta::assert_snapshot;
-use ra_db::fixture::WithFixture;
 use test_utils::mark;
 
-use crate::test_db::TestDB;
-
-use super::{infer, infer_with_mismatches, type_at, type_at_pos};
+use super::{check_types, infer, infer_with_mismatches};
 
 #[test]
 fn infer_await() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
-
+//- /main.rs crate:main deps:core
 struct IntFuture;
 
 impl Future for IntFuture {
@@ -21,10 +17,10 @@ impl Future for IntFuture {
 fn test() {
     let r = IntFuture;
     let v = r.await;
-    v<|>;
-}
+    v;
+} //^ u64
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     #[lang = "future_trait"]
@@ -32,18 +28,15 @@ mod future {
         type Output;
     }
 }
-
 "#,
     );
-    assert_eq!("u64", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_async() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
-
+//- /main.rs crate:main deps:core
 async fn foo() -> u64 {
     128
 }
@@ -51,10 +44,10 @@ async fn foo() -> u64 {
 fn test() {
     let r = foo();
     let v = r.await;
-    v<|>;
-}
+    v;
+} //^ u64
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     #[lang = "future_trait"]
@@ -62,28 +55,25 @@ mod future {
         type Output;
     }
 }
-
 "#,
     );
-    assert_eq!("u64", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_desugar_async() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
-
+//- /main.rs crate:main deps:core
 async fn foo() -> u64 {
     128
 }
 
 fn test() {
     let r = foo();
-    r<|>;
-}
+    r;
+} //^ impl Future<Output = u64>
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     trait Future {
@@ -93,23 +83,20 @@ mod future {
 
 "#,
     );
-    assert_eq!("impl Future<Output = u64>", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_try() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
-
+//- /main.rs crate:main deps:core
 fn test() {
     let r: Result<i32, u64> = Result::Ok(1);
     let v = r?;
-    v<|>;
-}
-
-//- /std.rs crate:std
+    v;
+} //^ i32
 
+//- /core.rs crate:core
 #[prelude_import] use ops::*;
 mod ops {
     trait Try {
@@ -130,30 +117,26 @@ mod result {
         type Error = E;
     }
 }
-
 "#,
     );
-    assert_eq!("i32", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_for_loop() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
-
-use std::collections::Vec;
+//- /main.rs crate:main deps:core,alloc
+use alloc::collections::Vec;
 
 fn test() {
     let v = Vec::new();
     v.push("foo");
     for x in v {
-        x<|>;
-    }
+        x;
+    } //^ &str
 }
 
-//- /std.rs crate:std
-
+//- /core.rs crate:core
 #[prelude_import] use iter::*;
 mod iter {
     trait IntoIterator {
@@ -161,6 +144,7 @@ mod iter {
     }
 }
 
+//- /alloc.rs crate:alloc deps:core
 mod collections {
     struct Vec<T> {}
     impl<T> Vec<T> {
@@ -168,21 +152,19 @@ mod collections {
         fn push(&mut self, t: T) { }
     }
 
-    impl<T> crate::iter::IntoIterator for Vec<T> {
+    impl<T> IntoIterator for Vec<T> {
         type Item=T;
     }
 }
 "#,
     );
-    assert_eq!("&str", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_ops_neg() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
-
 struct Bar;
 struct Foo;
 
@@ -193,11 +175,10 @@ impl std::ops::Neg for Bar {
 fn test() {
     let a = Bar;
     let b = -a;
-    b<|>;
-}
+    b;
+} //^ Foo
 
 //- /std.rs crate:std
-
 #[prelude_import] use ops::*;
 mod ops {
     #[lang = "neg"]
@@ -207,15 +188,13 @@ mod ops {
 }
 "#,
     );
-    assert_eq!("Foo", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_ops_not() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
-
 struct Bar;
 struct Foo;
 
@@ -226,11 +205,10 @@ impl std::ops::Not for Bar {
 fn test() {
     let a = Bar;
     let b = !a;
-    b<|>;
-}
+    b;
+} //^ Foo
 
 //- /std.rs crate:std
-
 #[prelude_import] use ops::*;
 mod ops {
     #[lang = "not"]
@@ -240,7 +218,6 @@ mod ops {
 }
 "#,
     );
-    assert_eq!("Foo", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -257,16 +234,16 @@ fn test() {
 }
 "#),
         @r###"
-    86..87 't': T
-    92..94 '{}': ()
-    105..144 '{     ...(s); }': ()
-    115..116 's': S<u32>
-    119..120 'S': S<u32>(u32) -> S<u32>
-    119..129 'S(unknown)': S<u32>
-    121..128 'unknown': u32
-    135..138 'foo': fn foo<S<u32>>(S<u32>)
-    135..141 'foo(s)': ()
-    139..140 's': S<u32>
+    85..86 't': T
+    91..93 '{}': ()
+    104..143 '{     ...(s); }': ()
+    114..115 's': S<u32>
+    118..119 'S': S<u32>(u32) -> S<u32>
+    118..128 'S(unknown)': S<u32>
+    120..127 'unknown': u32
+    134..137 'foo': fn foo<S<u32>>(S<u32>)
+    134..140 'foo(s)': ()
+    138..139 's': S<u32>
     "###
     );
 }
@@ -285,17 +262,17 @@ fn test() {
 }
 "#),
         @r###"
-    87..88 't': T
-    98..100 '{}': ()
-    111..163 '{     ...(s); }': ()
-    121..122 's': S<u32>
-    125..126 'S': S<u32>(u32) -> S<u32>
-    125..135 'S(unknown)': S<u32>
-    127..134 'unknown': u32
-    145..146 'x': u32
-    154..157 'foo': fn foo<u32, S<u32>>(S<u32>) -> u32
-    154..160 'foo(s)': u32
-    158..159 's': S<u32>
+    86..87 't': T
+    97..99 '{}': ()
+    110..162 '{     ...(s); }': ()
+    120..121 's': S<u32>
+    124..125 'S': S<u32>(u32) -> S<u32>
+    124..134 'S(unknown)': S<u32>
+    126..133 'unknown': u32
+    144..145 'x': u32
+    153..156 'foo': fn foo<u32, S<u32>>(S<u32>) -> u32
+    153..159 'foo(s)': u32
+    157..158 's': S<u32>
     "###
     );
 }
@@ -313,12 +290,12 @@ trait Trait {
 }
 "#),
         @r###"
-    27..31 'self': &Self
-    53..57 'self': &Self
-    62..97 '{     ...     }': ()
-    76..77 'x': i64
-    80..84 'self': &Self
-    80..90 'self.foo()': i64
+    26..30 'self': &Self
+    52..56 'self': &Self
+    61..96 '{     ...     }': ()
+    75..76 'x': i64
+    79..83 'self': &Self
+    79..89 'self.foo()': i64
     "###
     );
 }
@@ -337,12 +314,12 @@ trait Trait: SuperTrait {
 }
 "#),
         @r###"
-    32..36 'self': &Self
-    86..90 'self': &Self
-    95..130 '{     ...     }': ()
-    109..110 'x': i64
-    113..117 'self': &Self
-    113..123 'self.foo()': i64
+    31..35 'self': &Self
+    85..89 'self': &Self
+    94..129 '{     ...     }': ()
+    108..109 'x': i64
+    112..116 'self': &Self
+    112..122 'self.foo()': i64
     "###
     );
 }
@@ -364,15 +341,15 @@ fn test<T: Iterable>() {
 }
 "#),
         @r###"
-    108..261 '{     ...ter; }': ()
-    118..119 'x': u32
-    145..146 '1': u32
-    156..157 'y': Iterable::Item<T>
-    183..192 'no_matter': Iterable::Item<T>
-    202..203 'z': Iterable::Item<T>
-    215..224 'no_matter': Iterable::Item<T>
-    234..235 'a': Iterable::Item<T>
-    249..258 'no_matter': Iterable::Item<T>
+    107..260 '{     ...ter; }': ()
+    117..118 'x': u32
+    144..145 '1': u32
+    155..156 'y': Iterable::Item<T>
+    182..191 'no_matter': Iterable::Item<T>
+    201..202 'z': Iterable::Item<T>
+    214..223 'no_matter': Iterable::Item<T>
+    233..234 'a': Iterable::Item<T>
+    248..257 'no_matter': Iterable::Item<T>
     "###
     );
 }
@@ -396,25 +373,25 @@ fn test() {
 }
 "#),
         @r###"
-    106..107 't': T
-    123..125 '{}': ()
-    147..148 't': T
-    178..180 '{}': ()
-    202..203 't': T
-    221..223 '{}': ()
-    234..300 '{     ...(S); }': ()
-    244..245 'x': u32
-    248..252 'foo1': fn foo1<S>(S) -> <S as Iterable>::Item
-    248..255 'foo1(S)': u32
-    253..254 'S': S
-    265..266 'y': u32
-    269..273 'foo2': fn foo2<S>(S) -> <S as Iterable>::Item
-    269..276 'foo2(S)': u32
-    274..275 'S': S
-    286..287 'z': u32
-    290..294 'foo3': fn foo3<S>(S) -> <S as Iterable>::Item
-    290..297 'foo3(S)': u32
-    295..296 'S': S
+    105..106 't': T
+    122..124 '{}': ()
+    146..147 't': T
+    177..179 '{}': ()
+    201..202 't': T
+    220..222 '{}': ()
+    233..299 '{     ...(S); }': ()
+    243..244 'x': u32
+    247..251 'foo1': fn foo1<S>(S) -> <S as Iterable>::Item
+    247..254 'foo1(S)': u32
+    252..253 'S': S
+    264..265 'y': u32
+    268..272 'foo2': fn foo2<S>(S) -> <S as Iterable>::Item
+    268..275 'foo2(S)': u32
+    273..274 'S': S
+    285..286 'z': u32
+    289..293 'foo3': fn foo3<S>(S) -> <S as Iterable>::Item
+    289..296 'foo3(S)': u32
+    294..295 'S': S
     "###
     );
 }
@@ -431,9 +408,9 @@ fn test<T: Iterable<Item=u32>>() {
 }
 "#),
         @r###"
-    67..100 '{     ...own; }': ()
-    77..78 'y': u32
-    90..97 'unknown': u32
+    66..99 '{     ...own; }': ()
+    76..77 'y': u32
+    89..96 'unknown': u32
     "###
     );
 }
@@ -446,13 +423,13 @@ const A: u32 = 1 + 1;
 static B: u64 = { let x = 1; x };
 "#),
         @r###"
-    16..17 '1': u32
-    16..21 '1 + 1': u32
-    20..21 '1': u32
-    39..55 '{ let ...1; x }': u64
-    45..46 'x': u64
-    49..50 '1': u64
-    52..53 'x': u64
+    15..16 '1': u32
+    15..20 '1 + 1': u32
+    19..20 '1': u32
+    38..54 '{ let ...1; x }': u64
+    44..45 'x': u64
+    48..49 '1': u64
+    51..52 'x': u64
     "###
     );
 }
@@ -469,17 +446,17 @@ fn test() -> u64 {
 }
 "#),
         @r###"
-    38..87 '{     ... a.1 }': u64
-    48..49 'a': S
-    52..53 'S': S(i32, u64) -> S
-    52..59 'S(4, 6)': S
-    54..55 '4': i32
-    57..58 '6': u64
-    69..70 'b': i32
-    73..74 'a': S
-    73..76 'a.0': i32
-    82..83 'a': S
-    82..85 'a.1': u64
+    37..86 '{     ... a.1 }': u64
+    47..48 'a': S
+    51..52 'S': S(i32, u64) -> S
+    51..58 'S(4, 6)': S
+    53..54 '4': i32
+    56..57 '6': u64
+    68..69 'b': i32
+    72..73 'a': S
+    72..75 'a.0': i32
+    81..82 'a': S
+    81..84 'a.1': u64
     "###
     );
 }
@@ -496,24 +473,24 @@ fn test() -> u64 {
 }
 "#),
         @r###"
-    44..102 '{     ...0(2) }': u64
-    54..55 'a': S
-    58..59 'S': S(fn(u32) -> u64) -> S
-    58..68 'S(|i| 2*i)': S
-    60..67 '|i| 2*i': |u32| -> u64
-    61..62 'i': u32
-    64..65 '2': u32
-    64..67 '2*i': u32
-    66..67 'i': u32
-    78..79 'b': u64
-    82..83 'a': S
-    82..85 'a.0': fn(u32) -> u64
-    82..88 'a.0(4)': u64
-    86..87 '4': u32
-    94..95 'a': S
-    94..97 'a.0': fn(u32) -> u64
-    94..100 'a.0(2)': u64
-    98..99 '2': u32
+    43..101 '{     ...0(2) }': u64
+    53..54 'a': S
+    57..58 'S': S(fn(u32) -> u64) -> S
+    57..67 'S(|i| 2*i)': S
+    59..66 '|i| 2*i': |u32| -> u64
+    60..61 'i': u32
+    63..64 '2': u32
+    63..66 '2*i': u32
+    65..66 'i': u32
+    77..78 'b': u64
+    81..82 'a': S
+    81..84 'a.0': fn(u32) -> u64
+    81..87 'a.0(4)': u64
+    85..86 '4': u32
+    93..94 'a': S
+    93..96 'a.0': fn(u32) -> u64
+    93..99 'a.0(2)': u64
+    97..98 '2': u32
     "###
     );
 }
@@ -535,10 +512,9 @@ fn indexing_arrays() {
 
 #[test]
 fn infer_ops_index() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
-
 struct Bar;
 struct Foo;
 
@@ -549,11 +525,46 @@ impl std::ops::Index<u32> for Bar {
 fn test() {
     let a = Bar;
     let b = a[1u32];
-    b<|>;
-}
+    b;
+} //^ Foo
 
 //- /std.rs crate:std
+#[prelude_import] use ops::*;
+mod ops {
+    #[lang = "index"]
+    pub trait Index<Idx> {
+        type Output;
+    }
+}
+"#,
+    );
+}
+
+#[test]
+fn infer_ops_index_int() {
+    check_types(
+        r#"
+//- /main.rs crate:main deps:std
+struct Bar;
+struct Foo;
+
+impl std::ops::Index<u32> for Bar {
+    type Output = Foo;
+}
+
+struct Range;
+impl std::ops::Index<Range> for Bar {
+    type Output = Bar;
+}
+
+fn test() {
+    let a = Bar;
+    let b = a[1];
+    b;
+  //^ Foo
+}
 
+//- /std.rs crate:std
 #[prelude_import] use ops::*;
 mod ops {
     #[lang = "index"]
@@ -563,19 +574,18 @@ mod ops {
 }
 "#,
     );
-    assert_eq!("Foo", type_at_pos(&db, pos));
 }
 
 #[test]
 fn infer_ops_index_autoderef() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
 fn test() {
     let a = &[1u32, 2, 3];
     let b = a[1u32];
-    b<|>;
-}
+    b;
+} //^ u32
 
 //- /std.rs crate:std
 impl<T> ops::Index<u32> for [T] {
@@ -591,14 +601,12 @@ mod ops {
 }
 "#,
     );
-    assert_eq!("u32", type_at_pos(&db, pos));
 }
 
 #[test]
 fn deref_trait() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 #[lang = "deref"]
 trait Deref {
     type Target;
@@ -616,16 +624,15 @@ impl S {
 }
 
 fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
+    (*s, s.foo());
+} //^ (S, u128)
 "#,
     );
-    assert_eq!(t, "(S, u128)");
 }
 
 #[test]
 fn deref_trait_with_inference_var() {
-    let t = type_at(
+    check_types(
         r#"
 //- /main.rs
 #[lang = "deref"]
@@ -645,19 +652,18 @@ fn foo(a: Arc<S>) {}
 
 fn test() {
     let a = new_arc();
-    let b = (*a)<|>;
+    let b = (*a);
+          //^ S
     foo(a);
 }
 "#,
     );
-    assert_eq!(t, "S");
 }
 
 #[test]
 fn deref_trait_infinite_recursion() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 #[lang = "deref"]
 trait Deref {
     type Target;
@@ -671,18 +677,16 @@ impl Deref for S {
 }
 
 fn test(s: S) {
-    s.foo()<|>;
-}
+    s.foo();
+}       //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn deref_trait_with_question_mark_size() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 #[lang = "deref"]
 trait Deref {
     type Target;
@@ -700,18 +704,16 @@ impl S {
 }
 
 fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
+    (*s, s.foo());
+} //^ (S, u128)
 "#,
     );
-    assert_eq!(t, "(S, u128)");
 }
 
 #[test]
 fn obligation_from_function_clause() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct S;
 
 trait Trait<T> {}
@@ -720,16 +722,15 @@ impl Trait<u32> for S {}
 fn foo<T: Trait<U>, U>(t: T) -> U {}
 
 fn test(s: S) {
-    foo(s)<|>;
-}
+    (foo(s));
+} //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
 fn obligation_from_method_clause() {
-    let t = type_at(
+    check_types(
         r#"
 //- /main.rs
 struct S;
@@ -743,18 +744,16 @@ impl O {
 }
 
 fn test() {
-    O.foo(S)<|>;
-}
+    O.foo(S);
+}      //^ isize
 "#,
     );
-    assert_eq!(t, "isize");
 }
 
 #[test]
 fn obligation_from_self_method_clause() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct S;
 
 trait Trait<T> {}
@@ -765,18 +764,16 @@ impl S {
 }
 
 fn test() {
-    S.foo()<|>;
-}
+    S.foo();
+}       //^ i64
 "#,
     );
-    assert_eq!(t, "i64");
 }
 
 #[test]
 fn obligation_from_impl_clause() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct S;
 
 trait Trait<T> {}
@@ -788,32 +785,30 @@ impl<U, T: Trait<U>> O<T> {
 }
 
 fn test(o: O<S>) {
-    o.foo()<|>;
-}
+    o.foo();
+}       //^ &str
 "#,
     );
-    assert_eq!(t, "&str");
 }
 
 #[test]
 fn generic_param_env_1() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Clone {}
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Clone for S {}
 impl<T> Trait for T where T: Clone {}
-fn test<T: Clone>(t: T) { t.foo()<|>; }
+fn test<T: Clone>(t: T) { t.foo(); }
+                             //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn generic_param_env_1_not_met() {
-    let t = type_at(
+    check_types(
         r#"
 //- /main.rs
 trait Clone {}
@@ -821,45 +816,42 @@ trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Clone for S {}
 impl<T> Trait for T where T: Clone {}
-fn test<T>(t: T) { t.foo()<|>; }
+fn test<T>(t: T) { t.foo(); }
+                       //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn generic_param_env_2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Trait for S {}
-fn test<T: Trait>(t: T) { t.foo()<|>; }
+fn test<T: Trait>(t: T) { t.foo(); }
+                              //^ u128
 "#,
     );
-    assert_eq!(t, "u128");
 }
 
 #[test]
 fn generic_param_env_2_not_met() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait { fn foo(self) -> u128; }
 struct S;
 impl Trait for S {}
-fn test<T>(t: T) { t.foo()<|>; }
+fn test<T>(t: T) { t.foo(); }
+                       //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn generic_param_env_deref() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 #[lang = "deref"]
 trait Deref {
     type Target;
@@ -868,17 +860,17 @@ trait Trait {}
 impl<T> Deref for T where T: Trait {
     type Target = i128;
 }
-fn test<T: Trait>(t: T) { (*t)<|>; }
+fn test<T: Trait>(t: T) { (*t); }
+                        //^ i128
 "#,
     );
-    assert_eq!(t, "i128");
 }
 
 #[test]
 fn associated_type_placeholder() {
-    let t = type_at(
+    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
+    check_types(
         r#"
-//- /main.rs
 pub trait ApplyL {
     type Out;
 }
@@ -891,19 +883,16 @@ impl<T> ApplyL for RefMutL<T> {
 
 fn test<T: ApplyL>() {
     let y: <RefMutL<T> as ApplyL>::Out = no_matter;
-    y<|>;
-}
+    y;
+} //^ ApplyL::Out<T>
 "#,
     );
-    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
-    assert_eq!(t, "ApplyL::Out<T>");
 }
 
 #[test]
 fn associated_type_placeholder_2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 pub trait ApplyL {
     type Out;
 }
@@ -911,11 +900,10 @@ fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
 
 fn test<T: ApplyL>(t: T) {
     let y = foo(t);
-    y<|>;
-}
+    y;
+} //^ ApplyL::Out<T>
 "#,
     );
-    assert_eq!(t, "ApplyL::Out<T>");
 }
 
 #[test]
@@ -944,34 +932,34 @@ fn test(x: impl Trait<u64>, y: &impl Trait<u32>) {
 }
 "#, true),
         @r###"
-    30..34 'self': &Self
-    55..59 'self': &Self
-    78..79 'x': impl Trait<u16>
-    98..100 '{}': ()
-    155..156 'x': impl Trait<u64>
-    175..176 'y': &impl Trait<u32>
-    196..324 '{     ...2(); }': ()
-    202..203 'x': impl Trait<u64>
-    209..210 'y': &impl Trait<u32>
-    220..221 'z': S<u16>
-    224..225 'S': S<u16>(u16) -> S<u16>
-    224..228 'S(1)': S<u16>
-    226..227 '1': u16
-    234..237 'bar': fn bar(S<u16>)
-    234..240 'bar(z)': ()
-    238..239 'z': S<u16>
-    246..247 'x': impl Trait<u64>
-    246..253 'x.foo()': u64
-    259..260 'y': &impl Trait<u32>
-    259..266 'y.foo()': u32
-    272..273 'z': S<u16>
-    272..279 'z.foo()': u16
-    285..286 'x': impl Trait<u64>
-    285..293 'x.foo2()': i64
-    299..300 'y': &impl Trait<u32>
-    299..307 'y.foo2()': i64
-    313..314 'z': S<u16>
-    313..321 'z.foo2()': i64
+    29..33 'self': &Self
+    54..58 'self': &Self
+    77..78 'x': impl Trait<u16>
+    97..99 '{}': ()
+    154..155 'x': impl Trait<u64>
+    174..175 'y': &impl Trait<u32>
+    195..323 '{     ...2(); }': ()
+    201..202 'x': impl Trait<u64>
+    208..209 'y': &impl Trait<u32>
+    219..220 'z': S<u16>
+    223..224 'S': S<u16>(u16) -> S<u16>
+    223..227 'S(1)': S<u16>
+    225..226 '1': u16
+    233..236 'bar': fn bar(S<u16>)
+    233..239 'bar(z)': ()
+    237..238 'z': S<u16>
+    245..246 'x': impl Trait<u64>
+    245..252 'x.foo()': u64
+    258..259 'y': &impl Trait<u32>
+    258..265 'y.foo()': u32
+    271..272 'z': S<u16>
+    271..278 'z.foo()': u16
+    284..285 'x': impl Trait<u64>
+    284..292 'x.foo2()': i64
+    298..299 'y': &impl Trait<u32>
+    298..306 'y.foo2()': i64
+    312..313 'z': S<u16>
+    312..320 'z.foo2()': i64
     "###
     );
 }
@@ -1005,39 +993,39 @@ fn test() {
 }
 "#, true),
         @r###"
-    156..157 'x': impl Trait
-    176..187 '{ loop {} }': T
-    178..185 'loop {}': !
-    183..185 '{}': ()
-    200..201 'x': impl Trait
-    220..231 '{ loop {} }': T
-    222..229 'loop {}': !
-    227..229 '{}': ()
-    301..510 '{     ... i32 }': ()
-    307..315 'Foo::bar': fn bar<{unknown}, {unknown}>(S) -> {unknown}
-    307..318 'Foo::bar(S)': {unknown}
-    316..317 'S': S
-    324..339 '<F as Foo>::bar': fn bar<F, {unknown}>(S) -> {unknown}
-    324..342 '<F as ...bar(S)': {unknown}
-    340..341 'S': S
-    348..354 'F::bar': fn bar<F, {unknown}>(S) -> {unknown}
-    348..357 'F::bar(S)': {unknown}
-    355..356 'S': S
-    363..378 'Foo::bar::<u32>': fn bar<{unknown}, u32>(S) -> u32
-    363..381 'Foo::b...32>(S)': u32
-    379..380 'S': S
-    387..409 '<F as ...:<u32>': fn bar<F, u32>(S) -> u32
-    387..412 '<F as ...32>(S)': u32
-    410..411 'S': S
-    419..422 'foo': fn foo<{unknown}>(S) -> {unknown}
-    419..425 'foo(S)': {unknown}
-    423..424 'S': S
-    431..441 'foo::<u32>': fn foo<u32>(S) -> u32
-    431..444 'foo::<u32>(S)': u32
-    442..443 'S': S
-    450..465 'foo::<u32, i32>': fn foo<u32>(S) -> u32
-    450..468 'foo::<...32>(S)': u32
-    466..467 'S': S
+    155..156 'x': impl Trait
+    175..186 '{ loop {} }': T
+    177..184 'loop {}': !
+    182..184 '{}': ()
+    199..200 'x': impl Trait
+    219..230 '{ loop {} }': T
+    221..228 'loop {}': !
+    226..228 '{}': ()
+    300..509 '{     ... i32 }': ()
+    306..314 'Foo::bar': fn bar<{unknown}, {unknown}>(S) -> {unknown}
+    306..317 'Foo::bar(S)': {unknown}
+    315..316 'S': S
+    323..338 '<F as Foo>::bar': fn bar<F, {unknown}>(S) -> {unknown}
+    323..341 '<F as ...bar(S)': {unknown}
+    339..340 'S': S
+    347..353 'F::bar': fn bar<F, {unknown}>(S) -> {unknown}
+    347..356 'F::bar(S)': {unknown}
+    354..355 'S': S
+    362..377 'Foo::bar::<u32>': fn bar<{unknown}, u32>(S) -> u32
+    362..380 'Foo::b...32>(S)': u32
+    378..379 'S': S
+    386..408 '<F as ...:<u32>': fn bar<F, u32>(S) -> u32
+    386..411 '<F as ...32>(S)': u32
+    409..410 'S': S
+    418..421 'foo': fn foo<{unknown}>(S) -> {unknown}
+    418..424 'foo(S)': {unknown}
+    422..423 'S': S
+    430..440 'foo::<u32>': fn foo<u32>(S) -> u32
+    430..443 'foo::<u32>(S)': u32
+    441..442 'S': S
+    449..464 'foo::<u32, i32>': fn foo<u32>(S) -> u32
+    449..467 'foo::<...32>(S)': u32
+    465..466 'S': S
     "###
     );
 }
@@ -1062,24 +1050,24 @@ fn test() {
 }
 "#, true),
         @r###"
-    88..92 'self': F<T>
-    94..95 'x': impl Trait
-    119..130 '{ loop {} }': (T, U)
-    121..128 'loop {}': !
-    126..128 '{}': ()
-    144..284 '{     ...ored }': ()
-    150..151 'F': F<{unknown}>
-    150..158 'F.foo(S)': ({unknown}, {unknown})
-    156..157 'S': S
-    164..172 'F::<u32>': F<u32>
-    164..179 'F::<u32>.foo(S)': (u32, {unknown})
-    177..178 'S': S
-    185..193 'F::<u32>': F<u32>
-    185..207 'F::<u3...32>(S)': (u32, i32)
-    205..206 'S': S
-    213..221 'F::<u32>': F<u32>
-    213..240 'F::<u3...32>(S)': (u32, i32)
-    238..239 'S': S
+    87..91 'self': F<T>
+    93..94 'x': impl Trait
+    118..129 '{ loop {} }': (T, U)
+    120..127 'loop {}': !
+    125..127 '{}': ()
+    143..283 '{     ...ored }': ()
+    149..150 'F': F<{unknown}>
+    149..157 'F.foo(S)': ({unknown}, {unknown})
+    155..156 'S': S
+    163..171 'F::<u32>': F<u32>
+    163..178 'F::<u32>.foo(S)': (u32, {unknown})
+    176..177 'S': S
+    184..192 'F::<u32>': F<u32>
+    184..206 'F::<u3...32>(S)': (u32, i32)
+    204..205 'S': S
+    212..220 'F::<u32>': F<u32>
+    212..239 'F::<u3...32>(S)': (u32, i32)
+    237..238 'S': S
     "###
     );
 }
@@ -1098,19 +1086,18 @@ fn test() {
 }
 "#, true),
         @r###"
-    23..24 'x': impl Trait
-    38..49 '{ loop {} }': ()
-    40..47 'loop {}': !
-    45..47 '{}': ()
-    91..124 '{     ...foo; }': ()
-    101..102 'f': fn(S)
-    118..121 'foo': fn foo(S)
+    22..23 'x': impl Trait
+    37..48 '{ loop {} }': ()
+    39..46 'loop {}': !
+    44..46 '{}': ()
+    90..123 '{     ...foo; }': ()
+    100..101 'f': fn(S)
+    117..120 'foo': fn foo(S)
     "###
     );
 }
 
 #[test]
-#[ignore]
 fn impl_trait() {
     assert_snapshot!(
         infer(r#"
@@ -1133,29 +1120,118 @@ fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
 }
 "#),
         @r###"
-    30..34 'self': &Self
-    55..59 'self': &Self
-    99..101 '{}': ()
-    111..112 'x': impl Trait<u64>
-    131..132 'y': &impl Trait<u64>
-    152..269 '{     ...2(); }': ()
-    158..159 'x': impl Trait<u64>
-    165..166 'y': &impl Trait<u64>
-    176..177 'z': impl Trait<u64>
-    180..183 'bar': fn bar() -> impl Trait<u64>
-    180..185 'bar()': impl Trait<u64>
-    191..192 'x': impl Trait<u64>
-    191..198 'x.foo()': u64
-    204..205 'y': &impl Trait<u64>
-    204..211 'y.foo()': u64
-    217..218 'z': impl Trait<u64>
-    217..224 'z.foo()': u64
-    230..231 'x': impl Trait<u64>
-    230..238 'x.foo2()': i64
-    244..245 'y': &impl Trait<u64>
-    244..252 'y.foo2()': i64
-    258..259 'z': impl Trait<u64>
-    258..266 'z.foo2()': i64
+    29..33 'self': &Self
+    54..58 'self': &Self
+    98..100 '{}': ()
+    110..111 'x': impl Trait<u64>
+    130..131 'y': &impl Trait<u64>
+    151..268 '{     ...2(); }': ()
+    157..158 'x': impl Trait<u64>
+    164..165 'y': &impl Trait<u64>
+    175..176 'z': impl Trait<u64>
+    179..182 'bar': fn bar() -> impl Trait<u64>
+    179..184 'bar()': impl Trait<u64>
+    190..191 'x': impl Trait<u64>
+    190..197 'x.foo()': u64
+    203..204 'y': &impl Trait<u64>
+    203..210 'y.foo()': u64
+    216..217 'z': impl Trait<u64>
+    216..223 'z.foo()': u64
+    229..230 'x': impl Trait<u64>
+    229..237 'x.foo2()': i64
+    243..244 'y': &impl Trait<u64>
+    243..251 'y.foo2()': i64
+    257..258 'z': impl Trait<u64>
+    257..265 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn simple_return_pos_impl_trait() {
+    mark::check!(lower_rpit);
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+}
+fn bar() -> impl Trait<u64> { loop {} }
+
+fn test() {
+    let a = bar();
+    a.foo();
+}
+"#),
+        @r###"
+    29..33 'self': &Self
+    71..82 '{ loop {} }': !
+    73..80 'loop {}': !
+    78..80 '{}': ()
+    94..129 '{     ...o(); }': ()
+    104..105 'a': impl Trait<u64>
+    108..111 'bar': fn bar() -> impl Trait<u64>
+    108..113 'bar()': impl Trait<u64>
+    119..120 'a': impl Trait<u64>
+    119..126 'a.foo()': u64
+    "###
+    );
+}
+
+#[test]
+fn more_return_pos_impl_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterator {
+    type Item;
+    fn next(&mut self) -> Self::Item;
+}
+trait Trait<T> {
+    fn foo(&self) -> T;
+}
+fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>) { loop {} }
+fn baz<T>(t: T) -> (impl Iterator<Item = impl Trait<T>>, impl Trait<T>) { loop {} }
+
+fn test() {
+    let (a, b) = bar();
+    a.next().foo();
+    b.foo();
+    let (c, d) = baz(1u128);
+    c.next().foo();
+    d.foo();
+}
+"#),
+        @r###"
+    49..53 'self': &mut Self
+    101..105 'self': &Self
+    184..195 '{ loop {} }': ({unknown}, {unknown})
+    186..193 'loop {}': !
+    191..193 '{}': ()
+    206..207 't': T
+    268..279 '{ loop {} }': ({unknown}, {unknown})
+    270..277 'loop {}': !
+    275..277 '{}': ()
+    291..413 '{     ...o(); }': ()
+    301..307 '(a, b)': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    302..303 'a': impl Iterator<Item = impl Trait<u32>>
+    305..306 'b': impl Trait<u64>
+    310..313 'bar': fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    310..315 'bar()': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    321..322 'a': impl Iterator<Item = impl Trait<u32>>
+    321..329 'a.next()': impl Trait<u32>
+    321..335 'a.next().foo()': u32
+    341..342 'b': impl Trait<u64>
+    341..348 'b.foo()': u64
+    358..364 '(c, d)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    359..360 'c': impl Iterator<Item = impl Trait<u128>>
+    362..363 'd': impl Trait<u128>
+    367..370 'baz': fn baz<u128>(u128) -> (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    367..377 'baz(1u128)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    371..376 '1u128': u128
+    383..384 'c': impl Iterator<Item = impl Trait<u128>>
+    383..391 'c.next()': impl Trait<u128>
+    383..397 'c.next().foo()': u128
+    403..404 'd': impl Trait<u128>
+    403..410 'd.foo()': u128
     "###
     );
 }
@@ -1183,29 +1259,29 @@ fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
 }
 "#),
         @r###"
-    30..34 'self': &Self
-    55..59 'self': &Self
-    98..100 '{}': ()
-    110..111 'x': dyn Trait<u64>
-    129..130 'y': &dyn Trait<u64>
-    149..266 '{     ...2(); }': ()
-    155..156 'x': dyn Trait<u64>
-    162..163 'y': &dyn Trait<u64>
-    173..174 'z': dyn Trait<u64>
-    177..180 'bar': fn bar() -> dyn Trait<u64>
-    177..182 'bar()': dyn Trait<u64>
-    188..189 'x': dyn Trait<u64>
-    188..195 'x.foo()': u64
-    201..202 'y': &dyn Trait<u64>
-    201..208 'y.foo()': u64
-    214..215 'z': dyn Trait<u64>
-    214..221 'z.foo()': u64
-    227..228 'x': dyn Trait<u64>
-    227..235 'x.foo2()': i64
-    241..242 'y': &dyn Trait<u64>
-    241..249 'y.foo2()': i64
-    255..256 'z': dyn Trait<u64>
-    255..263 'z.foo2()': i64
+    29..33 'self': &Self
+    54..58 'self': &Self
+    97..99 '{}': ()
+    109..110 'x': dyn Trait<u64>
+    128..129 'y': &dyn Trait<u64>
+    148..265 '{     ...2(); }': ()
+    154..155 'x': dyn Trait<u64>
+    161..162 'y': &dyn Trait<u64>
+    172..173 'z': dyn Trait<u64>
+    176..179 'bar': fn bar() -> dyn Trait<u64>
+    176..181 'bar()': dyn Trait<u64>
+    187..188 'x': dyn Trait<u64>
+    187..194 'x.foo()': u64
+    200..201 'y': &dyn Trait<u64>
+    200..207 'y.foo()': u64
+    213..214 'z': dyn Trait<u64>
+    213..220 'z.foo()': u64
+    226..227 'x': dyn Trait<u64>
+    226..234 'x.foo2()': i64
+    240..241 'y': &dyn Trait<u64>
+    240..248 'y.foo2()': i64
+    254..255 'z': dyn Trait<u64>
+    254..262 'z.foo2()': i64
     "###
     );
 }
@@ -1231,17 +1307,17 @@ fn test(s: S<u32, i32>) {
 }
 "#),
         @r###"
-    33..37 'self': &Self
-    103..107 'self': &S<T, U>
-    129..140 '{ loop {} }': &dyn Trait<T, U>
-    131..138 'loop {}': !
-    136..138 '{}': ()
-    176..180 'self': &Self
-    252..253 's': S<u32, i32>
-    268..290 '{     ...z(); }': ()
-    274..275 's': S<u32, i32>
-    274..281 's.bar()': &dyn Trait<u32, i32>
-    274..287 's.bar().baz()': (u32, i32)
+    32..36 'self': &Self
+    102..106 'self': &S<T, U>
+    128..139 '{ loop {} }': &dyn Trait<T, U>
+    130..137 'loop {}': !
+    135..137 '{}': ()
+    175..179 'self': &Self
+    251..252 's': S<u32, i32>
+    267..289 '{     ...z(); }': ()
+    273..274 's': S<u32, i32>
+    273..280 's.bar()': &dyn Trait<u32, i32>
+    273..286 's.bar().baz()': (u32, i32)
     "###
     );
 }
@@ -1265,22 +1341,22 @@ fn test(x: Trait, y: &Trait) -> u64 {
 }
 "#),
         @r###"
-    27..31 'self': &Self
-    61..63 '{}': ()
-    73..74 'x': dyn Trait
-    83..84 'y': &dyn Trait
-    101..176 '{     ...o(); }': ()
-    107..108 'x': dyn Trait
-    114..115 'y': &dyn Trait
-    125..126 'z': dyn Trait
-    129..132 'bar': fn bar() -> dyn Trait
-    129..134 'bar()': dyn Trait
-    140..141 'x': dyn Trait
-    140..147 'x.foo()': u64
-    153..154 'y': &dyn Trait
-    153..160 'y.foo()': u64
-    166..167 'z': dyn Trait
-    166..173 'z.foo()': u64
+    26..30 'self': &Self
+    60..62 '{}': ()
+    72..73 'x': dyn Trait
+    82..83 'y': &dyn Trait
+    100..175 '{     ...o(); }': ()
+    106..107 'x': dyn Trait
+    113..114 'y': &dyn Trait
+    124..125 'z': dyn Trait
+    128..131 'bar': fn bar() -> dyn Trait
+    128..133 'bar()': dyn Trait
+    139..140 'x': dyn Trait
+    139..146 'x.foo()': u64
+    152..153 'y': &dyn Trait
+    152..159 'y.foo()': u64
+    165..166 'z': dyn Trait
+    165..172 'z.foo()': u64
     "###
     );
 }
@@ -1294,13 +1370,13 @@ fn test(a: impl Trait + 'lifetime, b: impl 'lifetime, c: impl (Trait), d: impl (
 }
 "#),
         @r###"
-    24..25 'a': impl Trait + {error}
-    51..52 'b': impl {error}
-    70..71 'c': impl Trait
-    87..88 'd': impl {error}
-    108..109 'e': impl {error}
-    124..125 'f': impl Trait + {error}
-    148..151 '{ }': ()
+    23..24 'a': impl Trait + {error}
+    50..51 'b': impl {error}
+    69..70 'c': impl Trait
+    86..87 'd': impl {error}
+    107..108 'e': impl {error}
+    123..124 'f': impl Trait + {error}
+    147..150 '{ }': ()
     "###
     );
 }
@@ -1308,19 +1384,17 @@ fn test(a: impl Trait + 'lifetime, b: impl 'lifetime, c: impl (Trait), d: impl (
 #[test]
 #[ignore]
 fn error_bound_chalk() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait {
     fn foo(&self) -> u32 {}
 }
 
 fn test(x: (impl Trait + UnknownTrait)) {
-    x.foo()<|>;
-}
+    x.foo();
+}       //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
@@ -1349,48 +1423,48 @@ fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
 }
 "#),
         @r###"
-    50..51 't': T
-    78..80 '{}': ()
-    112..113 't': T
-    123..125 '{}': ()
-    155..156 't': T
-    166..169 '{t}': T
-    167..168 't': T
-    257..258 'x': T
-    263..264 'y': impl Trait<Type = i64>
-    290..398 '{     ...r>); }': ()
-    296..299 'get': fn get<T>(T) -> <T as Trait>::Type
-    296..302 'get(x)': u32
-    300..301 'x': T
-    308..312 'get2': fn get2<u32, T>(T) -> u32
-    308..315 'get2(x)': u32
-    313..314 'x': T
-    321..324 'get': fn get<impl Trait<Type = i64>>(impl Trait<Type = i64>) -> <impl Trait<Type = i64> as Trait>::Type
-    321..327 'get(y)': i64
-    325..326 'y': impl Trait<Type = i64>
-    333..337 'get2': fn get2<i64, impl Trait<Type = i64>>(impl Trait<Type = i64>) -> i64
-    333..340 'get2(y)': i64
-    338..339 'y': impl Trait<Type = i64>
-    346..349 'get': fn get<S<u64>>(S<u64>) -> <S<u64> as Trait>::Type
-    346..357 'get(set(S))': u64
-    350..353 'set': fn set<S<u64>>(S<u64>) -> S<u64>
-    350..356 'set(S)': S<u64>
-    354..355 'S': S<u64>
-    363..367 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
-    363..375 'get2(set(S))': u64
-    368..371 'set': fn set<S<u64>>(S<u64>) -> S<u64>
-    368..374 'set(S)': S<u64>
-    372..373 'S': S<u64>
-    381..385 'get2': fn get2<str, S<str>>(S<str>) -> str
-    381..395 'get2(S::<str>)': str
-    386..394 'S::<str>': S<str>
+    49..50 't': T
+    77..79 '{}': ()
+    111..112 't': T
+    122..124 '{}': ()
+    154..155 't': T
+    165..168 '{t}': T
+    166..167 't': T
+    256..257 'x': T
+    262..263 'y': impl Trait<Type = i64>
+    289..397 '{     ...r>); }': ()
+    295..298 'get': fn get<T>(T) -> <T as Trait>::Type
+    295..301 'get(x)': u32
+    299..300 'x': T
+    307..311 'get2': fn get2<u32, T>(T) -> u32
+    307..314 'get2(x)': u32
+    312..313 'x': T
+    320..323 'get': fn get<impl Trait<Type = i64>>(impl Trait<Type = i64>) -> <impl Trait<Type = i64> as Trait>::Type
+    320..326 'get(y)': i64
+    324..325 'y': impl Trait<Type = i64>
+    332..336 'get2': fn get2<i64, impl Trait<Type = i64>>(impl Trait<Type = i64>) -> i64
+    332..339 'get2(y)': i64
+    337..338 'y': impl Trait<Type = i64>
+    345..348 'get': fn get<S<u64>>(S<u64>) -> <S<u64> as Trait>::Type
+    345..356 'get(set(S))': u64
+    349..352 'set': fn set<S<u64>>(S<u64>) -> S<u64>
+    349..355 'set(S)': S<u64>
+    353..354 'S': S<u64>
+    362..366 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
+    362..374 'get2(set(S))': u64
+    367..370 'set': fn set<S<u64>>(S<u64>) -> S<u64>
+    367..373 'set(S)': S<u64>
+    371..372 'S': S<u64>
+    380..384 'get2': fn get2<str, S<str>>(S<str>) -> str
+    380..394 'get2(S::<str>)': str
+    385..393 'S::<str>': S<str>
     "###
     );
 }
 
 #[test]
 fn impl_trait_assoc_binding_projection_bug() {
-    let (db, pos) = TestDB::with_position(
+    check_types(
         r#"
 //- /main.rs crate:main deps:std
 pub trait Language {
@@ -1409,8 +1483,8 @@ trait Clone {
 
 fn api_walkthrough() {
     for node in foo() {
-        node.clone()<|>;
-    }
+        node.clone();
+    }            //^ {unknown}
 }
 
 //- /std.rs crate:std
@@ -1428,7 +1502,6 @@ mod iter {
 }
 "#,
     );
-    assert_eq!("{unknown}", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -1448,20 +1521,19 @@ fn test<T: Trait1<Type = u32>>(x: T) {
 }
 "#),
         @r###"
-    62..66 'self': Self
-    164..165 'x': T
-    170..186 '{     ...o(); }': ()
-    176..177 'x': T
-    176..183 'x.foo()': u32
+    61..65 'self': Self
+    163..164 'x': T
+    169..185 '{     ...o(); }': ()
+    175..176 'x': T
+    175..182 'x.foo()': u32
     "###
     );
 }
 
 #[test]
 fn where_clause_trait_in_scope_for_method_resolution() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 mod foo {
     trait Trait {
         fn foo(&self) -> u32 {}
@@ -1469,11 +1541,10 @@ mod foo {
 }
 
 fn test<T: foo::Trait>(x: T) {
-    x.foo()<|>;
-}
+    x.foo();
+}      //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
@@ -1494,15 +1565,15 @@ fn test<T: Trait1, U: Trait2>(x: T, y: U) {
 }
 "#),
         @r###"
-    50..54 'self': &Self
-    63..65 '{}': ()
-    182..183 'x': T
-    188..189 'y': U
-    194..223 '{     ...o(); }': ()
-    200..201 'x': T
-    200..207 'x.foo()': u32
-    213..214 'y': U
-    213..220 'y.foo()': u32
+    49..53 'self': &Self
+    62..64 '{}': ()
+    181..182 'x': T
+    187..188 'y': U
+    193..222 '{     ...o(); }': ()
+    199..200 'x': T
+    199..206 'x.foo()': u32
+    212..213 'y': U
+    212..219 'y.foo()': u32
     "###
     );
 }
@@ -1523,12 +1594,12 @@ fn test(x: &impl Trait1) {
 }
 "#),
         @r###"
-    50..54 'self': &Self
-    63..65 '{}': ()
-    116..117 'x': &impl Trait1
-    133..149 '{     ...o(); }': ()
-    139..140 'x': &impl Trait1
-    139..146 'x.foo()': u32
+    49..53 'self': &Self
+    62..64 '{}': ()
+    115..116 'x': &impl Trait1
+    132..148 '{     ...o(); }': ()
+    138..139 'x': &impl Trait1
+    138..145 'x.foo()': u32
     "###
     );
 }
@@ -1546,10 +1617,10 @@ fn test<T: A>(x: T) {
 }
 "#),
         @r###"
-    44..45 'x': T
-    50..66 '{     ...o(); }': ()
-    56..57 'x': T
-    56..63 'x.foo()': {unknown}
+    43..44 'x': T
+    49..65 '{     ...o(); }': ()
+    55..56 'x': T
+    55..62 'x.foo()': {unknown}
     "###
     );
 }
@@ -1573,17 +1644,17 @@ fn test() {
 }
 "#),
         @r###"
-    103..104 't': T
-    114..116 '{}': ()
-    146..147 't': T
-    157..160 '{t}': T
-    158..159 't': T
-    259..280 '{     ...S)); }': ()
-    265..269 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
-    265..277 'get2(set(S))': u64
-    270..273 'set': fn set<S<u64>>(S<u64>) -> S<u64>
-    270..276 'set(S)': S<u64>
-    274..275 'S': S<u64>
+    102..103 't': T
+    113..115 '{}': ()
+    145..146 't': T
+    156..159 '{t}': T
+    157..158 't': T
+    258..279 '{     ...S)); }': ()
+    264..268 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
+    264..276 'get2(set(S))': u64
+    269..272 'set': fn set<S<u64>>(S<u64>) -> S<u64>
+    269..275 'set(S)': S<u64>
+    273..274 'S': S<u64>
     "###
     );
 }
@@ -1603,15 +1674,15 @@ fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
 }
 "#),
         @r###"
-    57..61 'self': Self
-    63..67 'args': Args
-    150..151 'f': F
-    156..184 '{     ...2)); }': ()
-    162..163 'f': F
-    162..181 'f.call...1, 2))': u128
-    174..180 '(1, 2)': (u32, u64)
-    175..176 '1': u32
-    178..179 '2': u64
+    56..60 'self': Self
+    62..66 'args': Args
+    149..150 'f': F
+    155..183 '{     ...2)); }': ()
+    161..162 'f': F
+    161..180 'f.call...1, 2))': u128
+    173..179 '(1, 2)': (u32, u64)
+    174..175 '1': u32
+    177..178 '2': u64
     "###
     );
 }
@@ -1652,24 +1723,24 @@ fn test() {
 }
 "#),
         @r###"
-75..79 'self': Self
-81..85 'args': Args
-140..144 'self': &Self
-244..248 'self': &Bar<F>
-261..263 '{}': ()
-347..351 'self': Opt<T>
-353..354 'f': F
-369..371 '{}': ()
-385..501 '{     ...(f); }': ()
-395..398 'bar': Bar<fn(u8) -> u32>
-424..427 'bar': Bar<fn(u8) -> u32>
-424..433 'bar.foo()': {unknown}
-444..447 'opt': Opt<u8>
-466..467 'f': fn(u8) -> u32
-488..491 'opt': Opt<u8>
-488..498 'opt.map(f)': Opt<FnOnce::Output<fn(u8) -> u32, (u8,)>>
-496..497 'f': fn(u8) -> u32
-"###
+    74..78 'self': Self
+    80..84 'args': Args
+    139..143 'self': &Self
+    243..247 'self': &Bar<F>
+    260..262 '{}': ()
+    346..350 'self': Opt<T>
+    352..353 'f': F
+    368..370 '{}': ()
+    384..500 '{     ...(f); }': ()
+    394..397 'bar': Bar<fn(u8) -> u32>
+    423..426 'bar': Bar<fn(u8) -> u32>
+    423..432 'bar.foo()': (u8, u32)
+    443..446 'opt': Opt<u8>
+    465..466 'f': fn(u8) -> u32
+    487..490 'opt': Opt<u8>
+    487..497 'opt.map(f)': Opt<u32>
+    495..496 'f': fn(u8) -> u32
+    "###
     );
 }
 
@@ -1718,33 +1789,33 @@ fn test() {
 }
 "#),
         @r###"
-65..69 'self': &Self
-166..170 'self': Self
-172..176 'args': Args
-240..244 'self': &Foo
-255..257 '{}': ()
-335..336 'f': F
-355..357 '{}': ()
-444..690 '{     ...o(); }': ()
-454..459 'lazy1': Lazy<Foo, fn() -> T>
-476..485 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-476..493 'Lazy::...| Foo)': Lazy<Foo, fn() -> T>
-486..492 '|| Foo': || -> T
-489..492 'Foo': Foo
-503..505 'r1': {unknown}
-508..513 'lazy1': Lazy<Foo, fn() -> T>
-508..519 'lazy1.foo()': {unknown}
-561..576 'make_foo_fn_ptr': fn() -> Foo
-592..603 'make_foo_fn': fn make_foo_fn() -> Foo
-613..618 'lazy2': Lazy<Foo, fn() -> T>
-635..644 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> T>
-645..660 'make_foo_fn_ptr': fn() -> Foo
-671..673 'r2': {unknown}
-676..681 'lazy2': Lazy<Foo, fn() -> T>
-676..687 'lazy2.foo()': {unknown}
-550..552 '{}': ()
-"###
+    64..68 'self': &Self
+    165..169 'self': Self
+    171..175 'args': Args
+    239..243 'self': &Foo
+    254..256 '{}': ()
+    334..335 'f': F
+    354..356 '{}': ()
+    443..689 '{     ...o(); }': ()
+    453..458 'lazy1': Lazy<Foo, || -> Foo>
+    475..484 'Lazy::new': fn new<Foo, || -> Foo>(|| -> Foo) -> Lazy<Foo, || -> Foo>
+    475..492 'Lazy::...| Foo)': Lazy<Foo, || -> Foo>
+    485..491 '|| Foo': || -> Foo
+    488..491 'Foo': Foo
+    502..504 'r1': usize
+    507..512 'lazy1': Lazy<Foo, || -> Foo>
+    507..518 'lazy1.foo()': usize
+    560..575 'make_foo_fn_ptr': fn() -> Foo
+    591..602 'make_foo_fn': fn make_foo_fn() -> Foo
+    612..617 'lazy2': Lazy<Foo, fn() -> Foo>
+    634..643 'Lazy::new': fn new<Foo, fn() -> Foo>(fn() -> Foo) -> Lazy<Foo, fn() -> Foo>
+    634..660 'Lazy::...n_ptr)': Lazy<Foo, fn() -> Foo>
+    644..659 'make_foo_fn_ptr': fn() -> Foo
+    670..672 'r2': usize
+    675..680 'lazy2': Lazy<Foo, fn() -> Foo>
+    675..686 'lazy2.foo()': usize
+    549..551 '{}': ()
+    "###
     );
 }
 
@@ -1770,32 +1841,32 @@ fn test() {
 }
 "#),
         @r###"
-    148..152 'self': Option<T>
-    154..155 'f': F
-    173..175 '{}': ()
-    189..308 '{     ... 1); }': ()
-    199..200 'x': Option<u32>
-    203..215 'Option::Some': Some<u32>(u32) -> Option<u32>
-    203..221 'Option...(1u32)': Option<u32>
-    216..220 '1u32': u32
-    227..228 'x': Option<u32>
-    227..243 'x.map(...v + 1)': Option<u32>
-    233..242 '|v| v + 1': |u32| -> u32
-    234..235 'v': u32
-    237..238 'v': u32
-    237..242 'v + 1': u32
-    241..242 '1': u32
-    249..250 'x': Option<u32>
-    249..265 'x.map(... 1u64)': Option<u64>
-    255..264 '|_v| 1u64': |u32| -> u64
-    256..258 '_v': u32
-    260..264 '1u64': u64
-    275..276 'y': Option<i64>
-    292..293 'x': Option<u32>
-    292..305 'x.map(|_v| 1)': Option<i64>
-    298..304 '|_v| 1': |u32| -> i64
-    299..301 '_v': u32
-    303..304 '1': i64
+    147..151 'self': Option<T>
+    153..154 'f': F
+    172..174 '{}': ()
+    188..307 '{     ... 1); }': ()
+    198..199 'x': Option<u32>
+    202..214 'Option::Some': Some<u32>(u32) -> Option<u32>
+    202..220 'Option...(1u32)': Option<u32>
+    215..219 '1u32': u32
+    226..227 'x': Option<u32>
+    226..242 'x.map(...v + 1)': Option<u32>
+    232..241 '|v| v + 1': |u32| -> u32
+    233..234 'v': u32
+    236..237 'v': u32
+    236..241 'v + 1': u32
+    240..241 '1': u32
+    248..249 'x': Option<u32>
+    248..264 'x.map(... 1u64)': Option<u64>
+    254..263 '|_v| 1u64': |u32| -> u64
+    255..257 '_v': u32
+    259..263 '1u64': u64
+    274..275 'y': Option<i64>
+    291..292 'x': Option<u32>
+    291..304 'x.map(|_v| 1)': Option<i64>
+    297..303 '|_v| 1': |u32| -> i64
+    298..300 '_v': u32
+    302..303 '1': i64
     "###
     );
 }
@@ -1816,26 +1887,26 @@ fn test<F: FnOnce(u32) -> u64>(f: F) {
 }
 "#),
         @r###"
-    73..74 'f': F
-    79..155 '{     ...+ v; }': ()
-    85..86 'f': F
-    85..89 'f(1)': {unknown}
-    87..88 '1': i32
-    99..100 'g': |u64| -> i32
-    103..112 '|v| v + 1': |u64| -> i32
-    104..105 'v': u64
-    107..108 'v': u64
-    107..112 'v + 1': i32
-    111..112 '1': i32
-    118..119 'g': |u64| -> i32
-    118..125 'g(1u64)': i32
-    120..124 '1u64': u64
-    135..136 'h': |u128| -> u128
-    139..152 '|v| 1u128 + v': |u128| -> u128
-    140..141 'v': u128
-    143..148 '1u128': u128
-    143..152 '1u128 + v': u128
-    151..152 'v': u128
+    72..73 'f': F
+    78..154 '{     ...+ v; }': ()
+    84..85 'f': F
+    84..88 'f(1)': {unknown}
+    86..87 '1': i32
+    98..99 'g': |u64| -> i32
+    102..111 '|v| v + 1': |u64| -> i32
+    103..104 'v': u64
+    106..107 'v': u64
+    106..111 'v + 1': i32
+    110..111 '1': i32
+    117..118 'g': |u64| -> i32
+    117..124 'g(1u64)': i32
+    119..123 '1u64': u64
+    134..135 'h': |u128| -> u128
+    138..151 '|v| 1u128 + v': |u128| -> u128
+    139..140 'v': u128
+    142..147 '1u128': u128
+    142..151 '1u128 + v': u128
+    150..151 'v': u128
     "###
     );
 }
@@ -1868,61 +1939,83 @@ fn test() {
 }
 "#),
         @r###"
-    95..96 'x': T
-    101..102 'f': F
-    112..114 '{}': ()
-    148..149 'f': F
-    154..155 'x': T
-    165..167 '{}': ()
-    202..206 'self': S
-    254..258 'self': S
-    260..261 'x': T
-    266..267 'f': F
-    277..279 '{}': ()
-    317..321 'self': S
-    323..324 'f': F
-    329..330 'x': T
-    340..342 '{}': ()
-    356..515 '{     ... S); }': ()
-    366..368 'x1': u64
-    371..375 'foo1': fn foo1<S, u64, |S| -> u64>(S, |S| -> u64) -> u64
-    371..394 'foo1(S...hod())': u64
-    376..377 'S': S
-    379..393 '|s| s.method()': |S| -> u64
-    380..381 's': S
-    383..384 's': S
-    383..393 's.method()': u64
-    404..406 'x2': u64
-    409..413 'foo2': fn foo2<S, u64, |S| -> u64>(|S| -> u64, S) -> u64
-    409..432 'foo2(|...(), S)': u64
-    414..428 '|s| s.method()': |S| -> u64
-    415..416 's': S
-    418..419 's': S
-    418..428 's.method()': u64
-    430..431 'S': S
-    442..444 'x3': u64
-    447..448 'S': S
-    447..472 'S.foo1...hod())': u64
-    454..455 'S': S
-    457..471 '|s| s.method()': |S| -> u64
-    458..459 's': S
-    461..462 's': S
-    461..471 's.method()': u64
-    482..484 'x4': u64
-    487..488 'S': S
-    487..512 'S.foo2...(), S)': u64
-    494..508 '|s| s.method()': |S| -> u64
-    495..496 's': S
-    498..499 's': S
-    498..508 's.method()': u64
-    510..511 'S': S
+    94..95 'x': T
+    100..101 'f': F
+    111..113 '{}': ()
+    147..148 'f': F
+    153..154 'x': T
+    164..166 '{}': ()
+    201..205 'self': S
+    253..257 'self': S
+    259..260 'x': T
+    265..266 'f': F
+    276..278 '{}': ()
+    316..320 'self': S
+    322..323 'f': F
+    328..329 'x': T
+    339..341 '{}': ()
+    355..514 '{     ... S); }': ()
+    365..367 'x1': u64
+    370..374 'foo1': fn foo1<S, u64, |S| -> u64>(S, |S| -> u64) -> u64
+    370..393 'foo1(S...hod())': u64
+    375..376 'S': S
+    378..392 '|s| s.method()': |S| -> u64
+    379..380 's': S
+    382..383 's': S
+    382..392 's.method()': u64
+    403..405 'x2': u64
+    408..412 'foo2': fn foo2<S, u64, |S| -> u64>(|S| -> u64, S) -> u64
+    408..431 'foo2(|...(), S)': u64
+    413..427 '|s| s.method()': |S| -> u64
+    414..415 's': S
+    417..418 's': S
+    417..427 's.method()': u64
+    429..430 'S': S
+    441..443 'x3': u64
+    446..447 'S': S
+    446..471 'S.foo1...hod())': u64
+    453..454 'S': S
+    456..470 '|s| s.method()': |S| -> u64
+    457..458 's': S
+    460..461 's': S
+    460..470 's.method()': u64
+    481..483 'x4': u64
+    486..487 'S': S
+    486..511 'S.foo2...(), S)': u64
+    493..507 '|s| s.method()': |S| -> u64
+    494..495 's': S
+    497..498 's': S
+    497..507 's.method()': u64
+    509..510 'S': S
     "###
     );
 }
 
 #[test]
+fn fn_item_fn_trait() {
+    check_types(
+        r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+struct S;
+
+fn foo() -> S {}
+
+fn takes_closure<U, F: FnOnce() -> U>(f: F) -> U { f() }
+
+fn test() {
+    takes_closure(foo);
+} //^^^^^^^^^^^^^^^^^^ S
+"#,
+    );
+}
+
+#[test]
 fn unselected_projection_in_trait_env_1() {
-    let t = type_at(
+    check_types(
         r#"
 //- /main.rs
 trait Trait {
@@ -1935,18 +2028,16 @@ trait Trait2 {
 
 fn test<T: Trait>() where T::Item: Trait2 {
     let x: T::Item = no_matter;
-    x.foo()<|>;
-}
+    x.foo();
+}       //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
 fn unselected_projection_in_trait_env_2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait<T> {
     type Item;
 }
@@ -1957,11 +2048,10 @@ trait Trait2 {
 
 fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
     let x: T::Item = no_matter;
-    x.foo()<|>;
-}
+    x.foo();
+}       //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
@@ -1990,26 +2080,25 @@ impl Trait for S2 {
 }
 "#,
     ), @r###"
-    54..58 'self': &Self
-    60..61 'x': Trait::Item<Self>
-    140..144 'self': &S
-    146..147 'x': u32
-    161..175 '{ let y = x; }': ()
-    167..168 'y': u32
-    171..172 'x': u32
-    242..246 'self': &S2
-    248..249 'x': i32
-    265..279 '{ let y = x; }': ()
-    271..272 'y': i32
-    275..276 'x': i32
+    40..44 'self': &Self
+    46..47 'x': Trait::Item<Self>
+    126..130 'self': &S
+    132..133 'x': u32
+    147..161 '{ let y = x; }': ()
+    153..154 'y': u32
+    157..158 'x': u32
+    228..232 'self': &S2
+    234..235 'x': i32
+    251..265 '{ let y = x; }': ()
+    257..258 'y': i32
+    261..262 'x': i32
     "###);
 }
 
 #[test]
 fn unselected_projection_on_trait_self() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait {
     type Item;
 
@@ -2022,18 +2111,16 @@ impl Trait for S {
 }
 
 fn test() {
-    S.f()<|>;
-}
+    S.f();
+}     //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
 fn unselected_projection_chalk_fold() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Interner {}
 trait Fold<I: Interner, TI = I> {
     type Result;
@@ -2052,18 +2139,16 @@ where
 }
 
 fn foo<I: Interner>(interner: &I, t: Ty<I>) {
-    fold(interner, t)<|>;
-}
+    fold(interner, t);
+}     //^ Ty<I>
 "#,
     );
-    assert_eq!(t, "Ty<I>");
 }
 
 #[test]
 fn trait_impl_self_ty() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait<T> {
    fn foo(&self);
 }
@@ -2073,18 +2158,16 @@ struct S;
 impl Trait<Self> for S {}
 
 fn test() {
-    S.foo()<|>;
-}
+    S.foo();
+}       //^ ()
 "#,
     );
-    assert_eq!(t, "()");
 }
 
 #[test]
 fn trait_impl_self_ty_cycle() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Trait {
    fn foo(&self);
 }
@@ -2094,18 +2177,17 @@ struct S<T>;
 impl Trait for S<Self> {}
 
 fn test() {
-    S.foo()<|>;
-}
+    S.foo();
+}       //^ {unknown}
 "#,
     );
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn unselected_projection_in_trait_env_cycle_1() {
-    let t = type_at(
+    // this is a legitimate cycle
+    check_types(
         r#"
-//- /main.rs
 trait Trait {
     type Item;
 }
@@ -2113,17 +2195,16 @@ trait Trait {
 trait Trait2<T> {}
 
 fn test<T: Trait>() where T: Trait2<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
+    let x: T::Item = no_matter;
+}                       //^ {unknown}
 "#,
     );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn unselected_projection_in_trait_env_cycle_2() {
-    let t = type_at(
+    // this is a legitimate cycle
+    check_types(
         r#"
 //- /main.rs
 trait Trait<T> {
@@ -2131,19 +2212,16 @@ trait Trait<T> {
 }
 
 fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
+    let x: T::Item = no_matter;
+}                   //^ {unknown}
 "#,
     );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
 }
 
 #[test]
 fn inline_assoc_type_bounds_1() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Iterator {
     type Item;
 }
@@ -2159,29 +2237,26 @@ impl<T: Iterator> Iterator for S<T> {
 
 fn test<I: Iterator<Item: OtherTrait<u32>>>() {
     let x: <S<I> as Iterator>::Item;
-    x.foo()<|>;
-}
+    x.foo();
+}       //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
 fn inline_assoc_type_bounds_2() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 trait Iterator {
     type Item;
 }
 
 fn test<I: Iterator<Item: Iterator<Item = u32>>>() {
     let x: <<I as Iterator>::Item as Iterator>::Item;
-    x<|>;
-}
+    x;
+} //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
@@ -2241,15 +2316,15 @@ impl TokenStream for Rustc {
 }
 "#),
         @r###"
-    1062..1073 '{ loop {} }': T
-    1064..1071 'loop {}': !
-    1069..1071 '{}': ()
-    1137..1200 '{     ...     }': T
-    1151..1156 'group': G
-    1172..1176 'make': fn make<G>() -> G
-    1172..1178 'make()': G
-    1188..1192 'make': fn make<T>() -> T
-    1188..1194 'make()': T
+    1061..1072 '{ loop {} }': T
+    1063..1070 'loop {}': !
+    1068..1070 '{}': ()
+    1136..1199 '{     ...     }': T
+    1150..1155 'group': G
+    1171..1175 'make': fn make<G>() -> G
+    1171..1177 'make()': G
+    1187..1191 'make': fn make<T>() -> T
+    1187..1193 'make()': T
     "###
     );
 }
@@ -2276,37 +2351,37 @@ fn test() -> impl Trait<i32> {
 }
 "#, true),
         @r###"
-    27..28 'x': impl Trait<u32>
-    47..58 '{ loop {} }': ()
-    49..56 'loop {}': !
-    54..56 '{}': ()
-    69..70 'x': impl Trait<T>
-    92..103 '{ loop {} }': T
-    94..101 'loop {}': !
-    99..101 '{}': ()
-    172..183 '{ loop {} }': T
-    174..181 'loop {}': !
-    179..181 '{}': ()
-    214..310 '{     ...t()) }': S<{unknown}>
-    224..226 's1': S<u32>
-    229..230 'S': S<u32>(u32) -> S<u32>
-    229..241 'S(default())': S<u32>
-    231..238 'default': fn default<u32>() -> u32
-    231..240 'default()': u32
-    247..250 'foo': fn foo(S<u32>)
-    247..254 'foo(s1)': ()
-    251..253 's1': S<u32>
-    264..265 'x': i32
-    273..276 'bar': fn bar<i32>(S<i32>) -> i32
-    273..290 'bar(S(...lt()))': i32
-    277..278 'S': S<i32>(i32) -> S<i32>
-    277..289 'S(default())': S<i32>
-    279..286 'default': fn default<i32>() -> i32
-    279..288 'default()': i32
-    296..297 'S': S<{unknown}>({unknown}) -> S<{unknown}>
-    296..308 'S(default())': S<{unknown}>
-    298..305 'default': fn default<{unknown}>() -> {unknown}
-    298..307 'default()': {unknown}
+    26..27 'x': impl Trait<u32>
+    46..57 '{ loop {} }': ()
+    48..55 'loop {}': !
+    53..55 '{}': ()
+    68..69 'x': impl Trait<T>
+    91..102 '{ loop {} }': T
+    93..100 'loop {}': !
+    98..100 '{}': ()
+    171..182 '{ loop {} }': T
+    173..180 'loop {}': !
+    178..180 '{}': ()
+    213..309 '{     ...t()) }': S<{unknown}>
+    223..225 's1': S<u32>
+    228..229 'S': S<u32>(u32) -> S<u32>
+    228..240 'S(default())': S<u32>
+    230..237 'default': fn default<u32>() -> u32
+    230..239 'default()': u32
+    246..249 'foo': fn foo(S<u32>)
+    246..253 'foo(s1)': ()
+    250..252 's1': S<u32>
+    263..264 'x': i32
+    272..275 'bar': fn bar<i32>(S<i32>) -> i32
+    272..289 'bar(S(...lt()))': i32
+    276..277 'S': S<i32>(i32) -> S<i32>
+    276..288 'S(default())': S<i32>
+    278..285 'default': fn default<i32>() -> i32
+    278..287 'default()': i32
+    295..296 'S': S<{unknown}>({unknown}) -> S<{unknown}>
+    295..307 'S(default())': S<{unknown}>
+    297..304 'default': fn default<{unknown}>() -> {unknown}
+    297..306 'default()': {unknown}
     "###
     );
 }
@@ -2340,24 +2415,23 @@ fn main() {
 }
 "#),
         @r###"
-    147..149 '_v': F
-    192..195 '{ }': ()
-    207..238 '{     ... }); }': ()
-    213..223 'f::<(), _>': fn f<(), |&()| -> ()>(|&()| -> ())
-    213..235 'f::<()... z; })': ()
-    224..234 '|z| { z; }': |&()| -> ()
-    225..226 'z': &()
-    228..234 '{ z; }': ()
-    230..231 'z': &()
+    133..135 '_v': F
+    178..181 '{ }': ()
+    193..224 '{     ... }); }': ()
+    199..209 'f::<(), _>': fn f<(), |&()| -> ()>(|&()| -> ())
+    199..221 'f::<()... z; })': ()
+    210..220 '|z| { z; }': |&()| -> ()
+    211..212 'z': &()
+    214..220 '{ z; }': ()
+    216..217 'z': &()
     "###
     );
 }
 
 #[test]
 fn associated_type_bound() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 pub trait Trait {
     type Item: OtherTrait<u32>;
 }
@@ -2373,18 +2447,16 @@ impl<T: Trait> Trait for S<T> {
 
 fn test<T: Trait>() {
     let y: <S<T> as Trait>::Item = no_matter;
-    y.foo()<|>;
-}
+    y.foo();
+}       //^ u32
 "#,
     );
-    assert_eq!(t, "u32");
 }
 
 #[test]
 fn dyn_trait_through_chalk() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct Box<T> {}
 #[lang = "deref"]
 trait Deref {
@@ -2398,18 +2470,16 @@ trait Trait {
 }
 
 fn test(x: Box<dyn Trait>) {
-    x.foo()<|>;
-}
+    x.foo();
+}       //^ ()
 "#,
     );
-    assert_eq!(t, "()");
 }
 
 #[test]
 fn string_to_owned() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct String {}
 pub trait ToOwned {
     type Owned;
@@ -2419,11 +2489,10 @@ impl ToOwned for str {
     type Owned = String;
 }
 fn test() {
-    "foo".to_owned()<|>;
-}
+    "foo".to_owned();
+}               //^ String
 "#,
     );
-    assert_eq!(t, "String");
 }
 
 #[test]
@@ -2501,55 +2570,54 @@ fn main() {
 }
 "#),
         @r###"
-    240..244 'self': Self
-    246..247 'f': F
-    331..342 '{ loop {} }': FilterMap<Self, F>
-    333..340 'loop {}': !
-    338..340 '{}': ()
-    363..367 'self': Self
-    369..370 'f': F
-    419..430 '{ loop {} }': ()
-    421..428 'loop {}': !
-    426..428 '{}': ()
-    539..543 'self': Self
-    868..872 'self': I
-    879..899 '{     ...     }': I
-    889..893 'self': I
-    958..969 '{ loop {} }': Vec<T>
-    960..967 'loop {}': !
-    965..967 '{}': ()
-    1156..1287 '{     ... }); }': ()
-    1162..1177 'Vec::<i32>::new': fn new<i32>() -> Vec<i32>
-    1162..1179 'Vec::<...:new()': Vec<i32>
-    1162..1191 'Vec::<...iter()': IntoIter<i32>
-    1162..1256 'Vec::<...one })': FilterMap<IntoIter<i32>, |i32| -> Option<u32>>
-    1162..1284 'Vec::<... y; })': ()
-    1210..1255 '|x| if...None }': |i32| -> Option<u32>
-    1211..1212 'x': i32
-    1214..1255 'if x >...None }': Option<u32>
-    1217..1218 'x': i32
-    1217..1222 'x > 0': bool
-    1221..1222 '0': i32
-    1223..1241 '{ Some...u32) }': Option<u32>
-    1225..1229 'Some': Some<u32>(u32) -> Option<u32>
-    1225..1239 'Some(x as u32)': Option<u32>
-    1230..1231 'x': i32
-    1230..1238 'x as u32': u32
-    1247..1255 '{ None }': Option<u32>
-    1249..1253 'None': Option<u32>
-    1273..1283 '|y| { y; }': |u32| -> ()
-    1274..1275 'y': u32
-    1277..1283 '{ y; }': ()
-    1279..1280 'y': u32
+    226..230 'self': Self
+    232..233 'f': F
+    317..328 '{ loop {} }': FilterMap<Self, F>
+    319..326 'loop {}': !
+    324..326 '{}': ()
+    349..353 'self': Self
+    355..356 'f': F
+    405..416 '{ loop {} }': ()
+    407..414 'loop {}': !
+    412..414 '{}': ()
+    525..529 'self': Self
+    854..858 'self': I
+    865..885 '{     ...     }': I
+    875..879 'self': I
+    944..955 '{ loop {} }': Vec<T>
+    946..953 'loop {}': !
+    951..953 '{}': ()
+    1142..1273 '{     ... }); }': ()
+    1148..1163 'Vec::<i32>::new': fn new<i32>() -> Vec<i32>
+    1148..1165 'Vec::<...:new()': Vec<i32>
+    1148..1177 'Vec::<...iter()': IntoIter<i32>
+    1148..1242 'Vec::<...one })': FilterMap<IntoIter<i32>, |i32| -> Option<u32>>
+    1148..1270 'Vec::<... y; })': ()
+    1196..1241 '|x| if...None }': |i32| -> Option<u32>
+    1197..1198 'x': i32
+    1200..1241 'if x >...None }': Option<u32>
+    1203..1204 'x': i32
+    1203..1208 'x > 0': bool
+    1207..1208 '0': i32
+    1209..1227 '{ Some...u32) }': Option<u32>
+    1211..1215 'Some': Some<u32>(u32) -> Option<u32>
+    1211..1225 'Some(x as u32)': Option<u32>
+    1216..1217 'x': i32
+    1216..1224 'x as u32': u32
+    1233..1241 '{ None }': Option<u32>
+    1235..1239 'None': Option<u32>
+    1259..1269 '|y| { y; }': |u32| -> ()
+    1260..1261 'y': u32
+    1263..1269 '{ y; }': ()
+    1265..1266 'y': u32
     "###
     );
 }
 
 #[test]
 fn nested_assoc() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs
 struct Bar;
 struct Foo;
 
@@ -2572,11 +2640,10 @@ impl<T:A> B for T {
 }
 
 fn main() {
-    Bar::foo()<|>;
-}
+    Bar::foo();
+}          //^ Foo
 "#,
     );
-    assert_eq!(t, "Foo");
 }
 
 #[test]
@@ -2592,13 +2659,13 @@ fn test(x: &dyn Foo) {
 }
 "#, true),
         @r###"
-    22..23 'x': &dyn Foo
-    35..37 '{}': ()
-    47..48 'x': &dyn Foo
-    60..75 '{     foo(x); }': ()
-    66..69 'foo': fn foo(&dyn Foo)
-    66..72 'foo(x)': ()
-    70..71 'x': &dyn Foo
+    21..22 'x': &dyn Foo
+    34..36 '{}': ()
+    46..47 'x': &dyn Foo
+    59..74 '{     foo(x); }': ()
+    65..68 'foo': fn foo(&dyn Foo)
+    65..71 'foo(x)': ()
+    69..70 'x': &dyn Foo
     "###
     );
 }
@@ -2625,20 +2692,20 @@ fn test() {
 }
 "#, true),
         @r###"
-    111..115 'self': &Self
-    167..268 '{     ...t(); }': ()
-    173..179 'IsCopy': IsCopy
-    173..186 'IsCopy.test()': bool
-    192..199 'NotCopy': NotCopy
-    192..206 'NotCopy.test()': {unknown}
-    212..228 '(IsCop...sCopy)': (IsCopy, IsCopy)
-    212..235 '(IsCop...test()': bool
-    213..219 'IsCopy': IsCopy
-    221..227 'IsCopy': IsCopy
-    241..258 '(IsCop...tCopy)': (IsCopy, NotCopy)
-    241..265 '(IsCop...test()': {unknown}
-    242..248 'IsCopy': IsCopy
-    250..257 'NotCopy': NotCopy
+    110..114 'self': &Self
+    166..267 '{     ...t(); }': ()
+    172..178 'IsCopy': IsCopy
+    172..185 'IsCopy.test()': bool
+    191..198 'NotCopy': NotCopy
+    191..205 'NotCopy.test()': {unknown}
+    211..227 '(IsCop...sCopy)': (IsCopy, IsCopy)
+    211..234 '(IsCop...test()': bool
+    212..218 'IsCopy': IsCopy
+    220..226 'IsCopy': IsCopy
+    240..257 '(IsCop...tCopy)': (IsCopy, NotCopy)
+    240..264 '(IsCop...test()': {unknown}
+    241..247 'IsCopy': IsCopy
+    249..256 'NotCopy': NotCopy
     "###
     );
 }
@@ -2666,20 +2733,20 @@ fn test() {
 }
 "#, true),
         @r###"
-    42..44 '{}': ()
-    61..62 'T': {unknown}
-    69..71 '{}': ()
-    69..71: expected T, got ()
-    146..150 'self': &Self
-    202..282 '{     ...t(); }': ()
-    208..211 'foo': fn foo()
-    208..218 'foo.test()': bool
-    224..227 'bar': fn bar<{unknown}>({unknown}) -> {unknown}
-    224..234 'bar.test()': bool
-    240..246 'Struct': Struct(usize) -> Struct
-    240..253 'Struct.test()': bool
-    259..272 'Enum::Variant': Variant(usize) -> Enum
-    259..279 'Enum::...test()': bool
+    41..43 '{}': ()
+    60..61 'T': {unknown}
+    68..70 '{}': ()
+    68..70: expected T, got ()
+    145..149 'self': &Self
+    201..281 '{     ...t(); }': ()
+    207..210 'foo': fn foo()
+    207..217 'foo.test()': bool
+    223..226 'bar': fn bar<{unknown}>({unknown}) -> {unknown}
+    223..233 'bar.test()': bool
+    239..245 'Struct': Struct(usize) -> Struct
+    239..252 'Struct.test()': bool
+    258..271 'Enum::Variant': Variant(usize) -> Enum
+    258..278 'Enum::...test()': bool
     "###
     );
 }
@@ -2701,17 +2768,17 @@ fn test(f1: fn(), f2: fn(usize) -> u8, f3: fn(u8, u8) -> &u8) {
 }
 "#, true),
         @r###"
-    55..59 'self': &Self
-    109..111 'f1': fn()
-    119..121 'f2': fn(usize) -> u8
-    140..142 'f3': fn(u8, u8) -> &u8
-    163..211 '{     ...t(); }': ()
-    169..171 'f1': fn()
-    169..178 'f1.test()': bool
-    184..186 'f2': fn(usize) -> u8
-    184..193 'f2.test()': bool
-    199..201 'f3': fn(u8, u8) -> &u8
-    199..208 'f3.test()': bool
+    54..58 'self': &Self
+    108..110 'f1': fn()
+    118..120 'f2': fn(usize) -> u8
+    139..141 'f3': fn(u8, u8) -> &u8
+    162..210 '{     ...t(); }': ()
+    168..170 'f1': fn()
+    168..177 'f1.test()': bool
+    183..185 'f2': fn(usize) -> u8
+    183..192 'f2.test()': bool
+    198..200 'f3': fn(u8, u8) -> &u8
+    198..207 'f3.test()': bool
     "###
     );
 }
@@ -2734,36 +2801,36 @@ fn test() {
 }
 "#, true),
         @r###"
-    57..61 'self': &Self
-    114..229 '{     ...ized }': ()
-    120..123 '1u8': u8
-    120..130 '1u8.test()': bool
-    136..151 '(*"foo").test()': {unknown}
-    137..143 '*"foo"': str
-    138..143 '"foo"': &str
-    170..180 '(1u8, 1u8)': (u8, u8)
-    170..187 '(1u8, ...test()': bool
-    171..174 '1u8': u8
-    176..179 '1u8': u8
-    193..206 '(1u8, *"foo")': (u8, str)
-    193..213 '(1u8, ...test()': {unknown}
-    194..197 '1u8': u8
-    199..205 '*"foo"': str
-    200..205 '"foo"': &str
+    56..60 'self': &Self
+    113..228 '{     ...ized }': ()
+    119..122 '1u8': u8
+    119..129 '1u8.test()': bool
+    135..150 '(*"foo").test()': {unknown}
+    136..142 '*"foo"': str
+    137..142 '"foo"': &str
+    169..179 '(1u8, 1u8)': (u8, u8)
+    169..186 '(1u8, ...test()': bool
+    170..173 '1u8': u8
+    175..178 '1u8': u8
+    192..205 '(1u8, *"foo")': (u8, str)
+    192..212 '(1u8, ...test()': {unknown}
+    193..196 '1u8': u8
+    198..204 '*"foo"': str
+    199..204 '"foo"': &str
     "###
     );
 }
 
 #[test]
 fn integer_range_iterate() {
-    let t = type_at(
+    check_types(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 fn test() {
-    for x in 0..100 { x<|>; }
-}
+    for x in 0..100 { x; }
+}                   //^ i32
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 pub mod ops {
     pub struct Range<Idx> {
         pub start: Idx,
@@ -2796,5 +2863,235 @@ impl<A: Step> iter::Iterator for ops::Range<A> {
 }
 "#,
     );
-    assert_eq!(t, "i32");
+}
+
+#[test]
+fn infer_closure_arg() {
+    assert_snapshot!(
+        infer(
+            r#"
+            //- /lib.rs
+
+            enum Option<T> {
+                None,
+                Some(T)
+            }
+
+            fn foo() {
+                let s = Option::None;
+                let f = |x: Option<i32>| {};
+                (&f)(s)
+            }
+        "#
+        ),
+        @r###"
+    52..126 '{     ...)(s) }': ()
+    62..63 's': Option<i32>
+    66..78 'Option::None': Option<i32>
+    88..89 'f': |Option<i32>| -> ()
+    92..111 '|x: Op...2>| {}': |Option<i32>| -> ()
+    93..94 'x': Option<i32>
+    109..111 '{}': ()
+    117..124 '(&f)(s)': ()
+    118..120 '&f': &|Option<i32>| -> ()
+    119..120 'f': |Option<i32>| -> ()
+    122..123 's': Option<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_fn_trait_arg() {
+    assert_snapshot!(
+        infer(
+            r#"
+            //- /lib.rs deps:std
+
+            #[lang = "fn_once"]
+            pub trait FnOnce<Args> {
+                type Output;
+
+                extern "rust-call" fn call_once(&self, args: Args) -> Self::Output;
+            }
+
+            #[lang = "fn"]
+            pub trait Fn<Args>:FnOnce<Args> {
+                extern "rust-call" fn call(&self, args: Args) -> Self::Output;
+            }
+
+            enum Option<T> {
+                None,
+                Some(T)
+            }
+
+            fn foo<F, T>(f: F) -> T
+            where
+                F: Fn(Option<i32>) -> T,
+            {
+                let s = None;
+                f(s)
+            }
+        "#
+        ),
+        @r###"
+    101..105 'self': &Self
+    107..111 'args': Args
+    220..224 'self': &Self
+    226..230 'args': Args
+    313..314 'f': F
+    359..389 '{     ...f(s) }': T
+    369..370 's': Option<i32>
+    373..377 'None': Option<i32>
+    383..384 'f': F
+    383..387 'f(s)': T
+    385..386 's': Option<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_box_fn_arg() {
+    assert_snapshot!(
+        infer(
+            r#"
+            //- /lib.rs deps:std
+
+            #[lang = "fn_once"]
+            pub trait FnOnce<Args> {
+                type Output;
+
+                extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
+            }
+
+            #[lang = "deref"]
+            pub trait Deref {
+                type Target: ?Sized;
+
+                fn deref(&self) -> &Self::Target;
+            }
+
+            #[lang = "owned_box"]
+            pub struct Box<T: ?Sized> {
+                inner: *mut T,
+            }
+
+            impl<T: ?Sized> Deref for Box<T> {
+                type Target = T;
+
+                fn deref(&self) -> &T {
+                    &self.inner
+                }
+            }
+
+            enum Option<T> {
+                None,
+                Some(T)
+            }
+
+            fn foo() {
+                let s = Option::None;
+                let f: Box<dyn FnOnce(&Option<i32>)> = box (|ps| {});
+                f(&s)
+            }
+        "#
+        ),
+        @r###"
+    100..104 'self': Self
+    106..110 'args': Args
+    214..218 'self': &Self
+    384..388 'self': &Box<T>
+    396..423 '{     ...     }': &T
+    406..417 '&self.inner': &*mut T
+    407..411 'self': &Box<T>
+    407..417 'self.inner': *mut T
+    478..575 '{     ...(&s) }': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
+    488..489 's': Option<i32>
+    492..504 'Option::None': Option<i32>
+    514..515 'f': Box<dyn FnOnce<(&Option<i32>,)>>
+    549..562 'box (|ps| {})': Box<|{unknown}| -> ()>
+    554..561 '|ps| {}': |{unknown}| -> ()
+    555..557 'ps': {unknown}
+    559..561 '{}': ()
+    568..569 'f': Box<dyn FnOnce<(&Option<i32>,)>>
+    568..573 'f(&s)': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
+    570..572 '&s': &Option<i32>
+    571..572 's': Option<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_dyn_fn_output() {
+    check_types(
+        r#"
+#[lang = "fn_once"]
+pub trait FnOnce<Args> {
+    type Output;
+    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
+}
+
+#[lang = "fn"]
+pub trait Fn<Args>: FnOnce<Args> {
+    extern "rust-call" fn call(&self, args: Args) -> Self::Output;
+}
+
+fn foo() {
+    let f: &dyn Fn() -> i32;
+    f();
+  //^^^ i32
+}"#,
+    );
+}
+
+#[test]
+fn infer_dyn_fn_once_output() {
+    check_types(
+        r#"
+#[lang = "fn_once"]
+pub trait FnOnce<Args> {
+    type Output;
+    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
+}
+
+fn foo() {
+    let f: dyn FnOnce() -> i32;
+    f();
+  //^^^ i32
+}"#,
+    );
+}
+
+#[test]
+fn variable_kinds_1() {
+    check_types(
+        r#"
+trait Trait<T> { fn get(self, t: T) -> T; }
+struct S;
+impl Trait<u128> for S {}
+impl Trait<f32> for S {}
+fn test() {
+    S.get(1);
+  //^^^^^^^^ u128
+    S.get(1.);
+  //^^^^^^^^ f32
+}
+        "#,
+    );
+}
+
+#[test]
+fn variable_kinds_2() {
+    check_types(
+        r#"
+trait Trait { fn get(self) -> Self; }
+impl Trait for u128 {}
+impl Trait for f32 {}
+fn test() {
+    1.get();
+  //^^^^^^^ u128
+    (1.).get();
+  //^^^^^^^^^^ f32
+}
+        "#,
+    );
 }
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 6bc6d474c..3f6d2cf35 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -1,20 +1,19 @@
 //! Trait solving using Chalk.
-use std::{panic, sync::Arc};
+use std::sync::Arc;
 
 use chalk_ir::cast::Cast;
-use hir_def::{expr::ExprId, DefWithBodyId, ImplId, TraitId, TypeAliasId};
-use ra_db::{impl_intern_key, salsa, CrateId};
+use chalk_solve::Solver;
+use hir_def::{lang_item::LangItemTarget, TraitId};
+use ra_db::CrateId;
 use ra_prof::profile;
-use rustc_hash::FxHashSet;
 
-use crate::{db::HirDatabase, method_resolution::TyFingerprint, DebruijnIndex};
+use crate::{db::HirDatabase, DebruijnIndex, Substs};
 
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
 
 use self::chalk::{from_chalk, Interner, ToChalk};
 
 pub(crate) mod chalk;
-mod builtin;
 
 // This controls the maximum size of types Chalk considers. If we set this too
 // high, we can run into slow edge cases; if we set it too low, Chalk won't
@@ -31,37 +30,10 @@ struct ChalkContext<'a> {
     krate: CrateId,
 }
 
-fn create_chalk_solver() -> chalk_solve::Solver<Interner> {
-    let solver_choice = chalk_solve::SolverChoice::recursive();
-    solver_choice.into_solver()
-}
-
-/// Collects impls for the given trait in the whole dependency tree of `krate`.
-pub(crate) fn impls_for_trait_query(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    trait_: TraitId,
-    self_ty_fp: Option<TyFingerprint>,
-) -> Arc<[ImplId]> {
-    // FIXME: We could be a lot smarter here - because of the orphan rules and
-    // the fact that the trait and the self type need to be in the dependency
-    // tree of a crate somewhere for an impl to exist, we could skip looking in
-    // a lot of crates completely
-    let mut impls = FxHashSet::default();
-    // We call the query recursively here. On the one hand, this means we can
-    // reuse results from queries for different crates; on the other hand, this
-    // will only ever get called for a few crates near the root of the tree (the
-    // ones the user is editing), so this may actually be a waste of memory. I'm
-    // doing it like this mainly for simplicity for now.
-    for dep in &db.crate_graph()[krate].dependencies {
-        impls.extend(db.impls_for_trait(dep.crate_id, trait_, self_ty_fp).iter());
-    }
-    let crate_impl_defs = db.impls_in_crate(krate);
-    match self_ty_fp {
-        Some(fp) => impls.extend(crate_impl_defs.lookup_impl_defs_for_trait_and_ty(trait_, fp)),
-        None => impls.extend(crate_impl_defs.lookup_impl_defs_for_trait(trait_)),
-    }
-    impls.into_iter().collect()
+fn create_chalk_solver() -> chalk_recursive::RecursiveSolver<Interner> {
+    let overflow_depth = 100;
+    let caching_enabled = true;
+    chalk_recursive::RecursiveSolver::new(overflow_depth, caching_enabled)
 }
 
 /// A set of clauses that we assume to be true. E.g. if we are inside this function:
@@ -217,15 +189,7 @@ fn solution_from_chalk(
     solution: chalk_solve::Solution<Interner>,
 ) -> Solution {
     let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<Interner>>| {
-        let value = subst
-            .value
-            .iter(&Interner)
-            .map(|p| match p.ty(&Interner) {
-                Some(ty) => from_chalk(db, ty.clone()),
-                None => unimplemented!(),
-            })
-            .collect();
-        let result = Canonical { value, num_vars: subst.binders.len(&Interner) };
+        let result = from_chalk(db, subst);
         SolutionVariables(result)
     };
     match solution {
@@ -249,7 +213,7 @@ fn solution_from_chalk(
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct SolutionVariables(pub Canonical<Vec<Ty>>);
+pub struct SolutionVariables(pub Canonical<Substs>);
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 /// A (possible) solution for a proposed goal.
@@ -298,53 +262,12 @@ impl FnTrait {
             FnTrait::Fn => "fn",
         }
     }
-}
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ClosureFnTraitImplData {
-    def: DefWithBodyId,
-    expr: ExprId,
-    fn_trait: FnTrait,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct UnsizeToSuperTraitObjectData {
-    trait_: TraitId,
-    super_trait: TraitId,
-}
-
-/// An impl. Usually this comes from an impl block, but some built-in types get
-/// synthetic impls.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum Impl {
-    /// A normal impl from an impl block.
-    ImplDef(ImplId),
-    /// Closure types implement the Fn traits synthetically.
-    ClosureFnTraitImpl(ClosureFnTraitImplData),
-    /// [T; n]: Unsize<[T]>
-    UnsizeArray,
-    /// T: Unsize<dyn Trait> where T: Trait
-    UnsizeToTraitObject(TraitId),
-    /// dyn Trait: Unsize<dyn SuperTrait> if Trait: SuperTrait
-    UnsizeToSuperTraitObject(UnsizeToSuperTraitObjectData),
-}
-/// This exists just for Chalk, because our ImplIds are only unique per module.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct GlobalImplId(salsa::InternId);
-impl_intern_key!(GlobalImplId);
-
-/// An associated type value. Usually this comes from a `type` declaration
-/// inside an impl block, but for built-in impls we have to synthesize it.
-/// (We only need this because Chalk wants a unique ID for each of these.)
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum AssocTyValue {
-    /// A normal assoc type value from an impl block.
-    TypeAlias(TypeAliasId),
-    /// The output type of the Fn trait implementation.
-    ClosureFnTraitImplOutput(ClosureFnTraitImplData),
+    pub fn get_id(&self, db: &dyn HirDatabase, krate: CrateId) -> Option<TraitId> {
+        let target = db.lang_item(krate, self.lang_item_name().into())?;
+        match target {
+            LangItemTarget::TraitId(t) => Some(t),
+            _ => None,
+        }
+    }
 }
-/// This exists just for Chalk, because it needs a unique ID for each associated
-/// type value in an impl (even synthetic ones).
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct AssocTyValueId(salsa::InternId);
-impl_intern_key!(AssocTyValueId);
diff --git a/crates/ra_hir_ty/src/traits/builtin.rs b/crates/ra_hir_ty/src/traits/builtin.rs
deleted file mode 100644
index 88a422d2c..000000000
--- a/crates/ra_hir_ty/src/traits/builtin.rs
+++ /dev/null
@@ -1,377 +0,0 @@
-//! This module provides the built-in trait implementations, e.g. to make
-//! closures implement `Fn`.
-use hir_def::{expr::Expr, lang_item::LangItemTarget, TraitId, TypeAliasId};
-use hir_expand::name::name;
-use ra_db::CrateId;
-
-use super::{AssocTyValue, Impl, UnsizeToSuperTraitObjectData};
-use crate::{
-    db::HirDatabase,
-    utils::{all_super_traits, generics},
-    ApplicationTy, Binders, BoundVar, DebruijnIndex, GenericPredicate, Substs, TraitRef, Ty,
-    TypeCtor, TypeWalk,
-};
-
-pub(super) struct BuiltinImplData {
-    pub num_vars: usize,
-    pub trait_ref: TraitRef,
-    pub where_clauses: Vec<super::GenericPredicate>,
-    pub assoc_ty_values: Vec<AssocTyValue>,
-}
-
-pub(super) struct BuiltinImplAssocTyValueData {
-    pub impl_: Impl,
-    pub assoc_ty_id: TypeAliasId,
-    pub num_vars: usize,
-    pub value: Ty,
-}
-
-pub(super) fn get_builtin_impls(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    ty: &Ty,
-    // The first argument for the trait, if present
-    arg: &Option<Ty>,
-    trait_: TraitId,
-    mut callback: impl FnMut(Impl),
-) {
-    // Note: since impl_datum needs to be infallible, we need to make sure here
-    // that we have all prerequisites to build the respective impls.
-    if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Closure { def, expr }, .. }) = ty {
-        for &fn_trait in [super::FnTrait::FnOnce, super::FnTrait::FnMut, super::FnTrait::Fn].iter()
-        {
-            if let Some(actual_trait) = get_fn_trait(db, krate, fn_trait) {
-                if trait_ == actual_trait {
-                    let impl_ = super::ClosureFnTraitImplData { def: *def, expr: *expr, fn_trait };
-                    if check_closure_fn_trait_impl_prerequisites(db, krate, impl_) {
-                        callback(Impl::ClosureFnTraitImpl(impl_));
-                    }
-                }
-            }
-        }
-    }
-
-    let unsize_trait = get_unsize_trait(db, krate);
-    if let Some(actual_trait) = unsize_trait {
-        if trait_ == actual_trait {
-            get_builtin_unsize_impls(db, krate, ty, arg, callback);
-        }
-    }
-}
-
-fn get_builtin_unsize_impls(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    ty: &Ty,
-    // The first argument for the trait, if present
-    arg: &Option<Ty>,
-    mut callback: impl FnMut(Impl),
-) {
-    if !check_unsize_impl_prerequisites(db, krate) {
-        return;
-    }
-
-    if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Array, .. }) = ty {
-        callback(Impl::UnsizeArray);
-        return; // array is unsized, the rest of the impls shouldn't apply
-    }
-
-    if let Some(target_trait) = arg.as_ref().and_then(|t| t.dyn_trait_ref()) {
-        // FIXME what about more complicated dyn tys with marker traits?
-        if let Some(trait_ref) = ty.dyn_trait_ref() {
-            if trait_ref.trait_ != target_trait.trait_ {
-                let super_traits = all_super_traits(db.upcast(), trait_ref.trait_);
-                if super_traits.contains(&target_trait.trait_) {
-                    callback(Impl::UnsizeToSuperTraitObject(UnsizeToSuperTraitObjectData {
-                        trait_: trait_ref.trait_,
-                        super_trait: target_trait.trait_,
-                    }));
-                }
-            }
-        } else {
-            // FIXME only for sized types
-            callback(Impl::UnsizeToTraitObject(target_trait.trait_));
-        }
-    }
-}
-
-pub(super) fn impl_datum(db: &dyn HirDatabase, krate: CrateId, impl_: Impl) -> BuiltinImplData {
-    match impl_ {
-        Impl::ImplDef(_) => unreachable!(),
-        Impl::ClosureFnTraitImpl(data) => closure_fn_trait_impl_datum(db, krate, data),
-        Impl::UnsizeArray => array_unsize_impl_datum(db, krate),
-        Impl::UnsizeToTraitObject(trait_) => trait_object_unsize_impl_datum(db, krate, trait_),
-        Impl::UnsizeToSuperTraitObject(data) => {
-            super_trait_object_unsize_impl_datum(db, krate, data)
-        }
-    }
-}
-
-pub(super) fn associated_ty_value(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    data: AssocTyValue,
-) -> BuiltinImplAssocTyValueData {
-    match data {
-        AssocTyValue::TypeAlias(_) => unreachable!(),
-        AssocTyValue::ClosureFnTraitImplOutput(data) => {
-            closure_fn_trait_output_assoc_ty_value(db, krate, data)
-        }
-    }
-}
-
-// Closure Fn trait impls
-
-fn check_closure_fn_trait_impl_prerequisites(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> bool {
-    // the respective Fn/FnOnce/FnMut trait needs to exist
-    if get_fn_trait(db, krate, data.fn_trait).is_none() {
-        return false;
-    }
-
-    // FIXME: there are more assumptions that we should probably check here:
-    // the traits having no type params, FnOnce being a supertrait
-
-    // the FnOnce trait needs to exist and have an assoc type named Output
-    let fn_once_trait = match get_fn_trait(db, krate, super::FnTrait::FnOnce) {
-        Some(t) => t,
-        None => return false,
-    };
-    db.trait_data(fn_once_trait).associated_type_by_name(&name![Output]).is_some()
-}
-
-fn closure_fn_trait_impl_datum(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> BuiltinImplData {
-    // for some closure |X, Y| -> Z:
-    // impl<T, U, V> Fn<(T, U)> for closure<fn(T, U) -> V> { Output = V }
-
-    let trait_ = get_fn_trait(db, krate, data.fn_trait) // get corresponding fn trait
-        // the existence of the Fn trait has been checked before
-        .expect("fn trait for closure impl missing");
-
-    let num_args: u16 = match &db.body(data.def)[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let arg_ty = Ty::apply(
-        TypeCtor::Tuple { cardinality: num_args },
-        Substs::builder(num_args as usize)
-            .fill_with_bound_vars(DebruijnIndex::INNERMOST, 0)
-            .build(),
-    );
-    let sig_ty = Ty::apply(
-        TypeCtor::FnPtr { num_args },
-        Substs::builder(num_args as usize + 1)
-            .fill_with_bound_vars(DebruijnIndex::INNERMOST, 0)
-            .build(),
-    );
-
-    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
-
-    let trait_ref = TraitRef {
-        trait_,
-        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
-    };
-
-    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data);
-
-    BuiltinImplData {
-        num_vars: num_args as usize + 1,
-        trait_ref,
-        where_clauses: Vec::new(),
-        assoc_ty_values: vec![output_ty_id],
-    }
-}
-
-fn closure_fn_trait_output_assoc_ty_value(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> BuiltinImplAssocTyValueData {
-    let impl_ = Impl::ClosureFnTraitImpl(data);
-
-    let num_args: u16 = match &db.body(data.def)[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let output_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, num_args.into()));
-
-    let fn_once_trait =
-        get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
-
-    let output_ty_id = db
-        .trait_data(fn_once_trait)
-        .associated_type_by_name(&name![Output])
-        .expect("assoc ty value should not exist");
-
-    BuiltinImplAssocTyValueData {
-        impl_,
-        assoc_ty_id: output_ty_id,
-        num_vars: num_args as usize + 1,
-        value: output_ty,
-    }
-}
-
-// Array unsizing
-
-fn check_unsize_impl_prerequisites(db: &dyn HirDatabase, krate: CrateId) -> bool {
-    // the Unsize trait needs to exist and have two type parameters (Self and T)
-    let unsize_trait = match get_unsize_trait(db, krate) {
-        Some(t) => t,
-        None => return false,
-    };
-    let generic_params = generics(db.upcast(), unsize_trait.into());
-    generic_params.len() == 2
-}
-
-fn array_unsize_impl_datum(db: &dyn HirDatabase, krate: CrateId) -> BuiltinImplData {
-    // impl<T> Unsize<[T]> for [T; _]
-    // (this can be a single impl because we don't distinguish array sizes currently)
-
-    let trait_ = get_unsize_trait(db, krate) // get unsize trait
-        // the existence of the Unsize trait has been checked before
-        .expect("Unsize trait missing");
-
-    let var = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
-    let substs = Substs::builder(2)
-        .push(Ty::apply_one(TypeCtor::Array, var.clone()))
-        .push(Ty::apply_one(TypeCtor::Slice, var))
-        .build();
-
-    let trait_ref = TraitRef { trait_, substs };
-
-    BuiltinImplData {
-        num_vars: 1,
-        trait_ref,
-        where_clauses: Vec::new(),
-        assoc_ty_values: Vec::new(),
-    }
-}
-
-// Trait object unsizing
-
-fn trait_object_unsize_impl_datum(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    trait_: TraitId,
-) -> BuiltinImplData {
-    // impl<T, T1, ...> Unsize<dyn Trait<T1, ...>> for T where T: Trait<T1, ...>
-
-    let unsize_trait = get_unsize_trait(db, krate) // get unsize trait
-        // the existence of the Unsize trait has been checked before
-        .expect("Unsize trait missing");
-
-    let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
-
-    let target_substs = Substs::build_for_def(db, trait_)
-        .push(Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
-        .fill_with_bound_vars(DebruijnIndex::ONE, 1)
-        .build();
-    let num_vars = target_substs.len();
-    let target_trait_ref = TraitRef { trait_, substs: target_substs };
-    let target_bounds = vec![GenericPredicate::Implemented(target_trait_ref)];
-
-    let self_substs =
-        Substs::build_for_def(db, trait_).fill_with_bound_vars(DebruijnIndex::INNERMOST, 0).build();
-    let self_trait_ref = TraitRef { trait_, substs: self_substs };
-    let where_clauses = vec![GenericPredicate::Implemented(self_trait_ref)];
-
-    let impl_substs = Substs::builder(2).push(self_ty).push(Ty::Dyn(target_bounds.into())).build();
-
-    let trait_ref = TraitRef { trait_: unsize_trait, substs: impl_substs };
-
-    BuiltinImplData { num_vars, trait_ref, where_clauses, assoc_ty_values: Vec::new() }
-}
-
-fn super_trait_object_unsize_impl_datum(
-    db: &dyn HirDatabase,
-    krate: CrateId,
-    data: UnsizeToSuperTraitObjectData,
-) -> BuiltinImplData {
-    // impl<T1, ...> Unsize<dyn SuperTrait> for dyn Trait<T1, ...>
-
-    let unsize_trait = get_unsize_trait(db, krate) // get unsize trait
-        // the existence of the Unsize trait has been checked before
-        .expect("Unsize trait missing");
-
-    let self_substs = Substs::build_for_def(db, data.trait_)
-        .fill_with_bound_vars(DebruijnIndex::INNERMOST, 0)
-        .build();
-    let self_trait_ref = TraitRef { trait_: data.trait_, substs: self_substs.clone() };
-
-    let num_vars = self_substs.len() - 1;
-
-    // we need to go from our trait to the super trait, substituting type parameters
-    let path = crate::utils::find_super_trait_path(db.upcast(), data.trait_, data.super_trait);
-
-    let mut current_trait_ref = self_trait_ref.clone();
-    for t in path.into_iter().skip(1) {
-        let bounds = db.generic_predicates(current_trait_ref.trait_.into());
-        let super_trait_ref = bounds
-            .iter()
-            .find_map(|b| match &b.value {
-                GenericPredicate::Implemented(tr)
-                    if tr.trait_ == t
-                        && tr.substs[0]
-                            == Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0)) =>
-                {
-                    Some(Binders { value: tr, num_binders: b.num_binders })
-                }
-                _ => None,
-            })
-            .expect("trait bound for known super trait not found");
-        current_trait_ref = super_trait_ref.cloned().subst(&current_trait_ref.substs);
-    }
-
-    // We need to renumber the variables a bit now: from ^0.0, ^0.1, ^0.2, ...
-    // to ^0.0, ^1.0, ^1.1. The reason for this is that the first variable comes
-    // from the dyn Trait binder, while the other variables come from the impl.
-    let new_substs = Substs::builder(num_vars + 1)
-        .push(Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
-        .fill_with_bound_vars(DebruijnIndex::ONE, 0)
-        .build();
-
-    let self_bounds =
-        vec![GenericPredicate::Implemented(self_trait_ref.subst_bound_vars(&new_substs))];
-    let super_bounds =
-        vec![GenericPredicate::Implemented(current_trait_ref.subst_bound_vars(&new_substs))];
-
-    let substs = Substs::builder(2)
-        .push(Ty::Dyn(self_bounds.into()))
-        .push(Ty::Dyn(super_bounds.into()))
-        .build();
-
-    let trait_ref = TraitRef { trait_: unsize_trait, substs };
-
-    BuiltinImplData { num_vars, trait_ref, where_clauses: Vec::new(), assoc_ty_values: Vec::new() }
-}
-
-fn get_fn_trait(db: &dyn HirDatabase, krate: CrateId, fn_trait: super::FnTrait) -> Option<TraitId> {
-    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
-    match target {
-        LangItemTarget::TraitId(t) => Some(t),
-        _ => None,
-    }
-}
-
-fn get_unsize_trait(db: &dyn HirDatabase, krate: CrateId) -> Option<TraitId> {
-    let target = db.lang_item(krate, "unsize".into())?;
-    match target {
-        LangItemTarget::TraitId(t) => Some(t),
-        _ => None,
-    }
-}
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 61de3cc30..78d0bc43b 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -3,8 +3,8 @@ use std::sync::Arc;
 
 use log::debug;
 
-use chalk_ir::{fold::shift::Shift, GenericArg, TypeName};
-use chalk_solve::rust_ir::{self, WellKnownTrait};
+use chalk_ir::{fold::shift::Shift, CanonicalVarKinds, GenericArg, TypeName};
+use chalk_solve::rust_ir::{self, OpaqueTyDatumBound, WellKnownTrait};
 
 use hir_def::{
     lang_item::{lang_attr, LangItemTarget},
@@ -12,12 +12,17 @@ use hir_def::{
 };
 use ra_db::{salsa::InternKey, CrateId};
 
-use super::{builtin, AssocTyValue, ChalkContext, Impl};
+use super::ChalkContext;
 use crate::{
-    db::HirDatabase, display::HirDisplay, method_resolution::TyFingerprint, utils::generics,
-    CallableDef, DebruijnIndex, GenericPredicate, Substs, Ty, TypeCtor,
+    db::HirDatabase,
+    display::HirDisplay,
+    method_resolution::{TyFingerprint, ALL_FLOAT_FPS, ALL_INT_FPS},
+    utils::generics,
+    CallableDefId, DebruijnIndex, FnSig, GenericPredicate, Substs, Ty, TypeCtor,
+};
+use mapping::{
+    convert_where_clauses, generic_predicate_to_inline_bound, make_binders, TypeAliasAsValue,
 };
-use mapping::{convert_where_clauses, generic_predicate_to_inline_bound, make_binders};
 
 pub use self::interner::*;
 
@@ -48,6 +53,9 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     fn adt_datum(&self, struct_id: AdtId) -> Arc<StructDatum> {
         self.db.struct_datum(self.krate, struct_id)
     }
+    fn adt_repr(&self, _struct_id: AdtId) -> rust_ir::AdtRepr {
+        unreachable!()
+    }
     fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum> {
         self.db.impl_datum(self.krate, impl_id)
     }
@@ -63,32 +71,57 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         &self,
         trait_id: TraitId,
         parameters: &[GenericArg<Interner>],
+        binders: &CanonicalVarKinds<Interner>,
     ) -> Vec<ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
         let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
 
         let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref(&Interner).clone());
 
+        fn binder_kind(ty: &Ty, binders: &CanonicalVarKinds<Interner>) -> Option<chalk_ir::TyKind> {
+            if let Ty::Bound(bv) = ty {
+                let binders = binders.as_slice(&Interner);
+                if bv.debruijn == DebruijnIndex::INNERMOST {
+                    if let chalk_ir::VariableKind::Ty(tk) = binders[bv.index].kind {
+                        return Some(tk);
+                    }
+                }
+            }
+            None
+        }
+
         let self_ty_fp = TyFingerprint::for_impl(&ty);
+        let fps: &[TyFingerprint] = match binder_kind(&ty, binders) {
+            Some(chalk_ir::TyKind::Integer) => &ALL_INT_FPS,
+            Some(chalk_ir::TyKind::Float) => &ALL_FLOAT_FPS,
+            _ => self_ty_fp.as_ref().map(std::slice::from_ref).unwrap_or(&[]),
+        };
 
         // Note: Since we're using impls_for_trait, only impls where the trait
         // can be resolved should ever reach Chalk. `impl_datum` relies on that
         // and will panic if the trait can't be resolved.
-        let mut result: Vec<_> = self
-            .db
-            .impls_for_trait(self.krate, trait_, self_ty_fp)
-            .iter()
-            .copied()
-            .map(Impl::ImplDef)
-            .map(|impl_| impl_.to_chalk(self.db))
-            .collect();
-
-        let arg: Option<Ty> =
-            parameters.get(1).map(|p| from_chalk(self.db, p.assert_ty_ref(&Interner).clone()));
-
-        builtin::get_builtin_impls(self.db, self.krate, &ty, &arg, trait_, |i| {
-            result.push(i.to_chalk(self.db))
-        });
+        let in_deps = self.db.trait_impls_in_deps(self.krate);
+        let in_self = self.db.trait_impls_in_crate(self.krate);
+        let impl_maps = [in_deps, in_self];
+
+        let id_to_chalk = |id: hir_def::ImplId| id.to_chalk(self.db);
+
+        let result: Vec<_> = if fps.is_empty() {
+            debug!("Unrestricted search for {:?} impls...", trait_);
+            impl_maps
+                .iter()
+                .flat_map(|crate_impl_defs| crate_impl_defs.for_trait(trait_).map(id_to_chalk))
+                .collect()
+        } else {
+            impl_maps
+                .iter()
+                .flat_map(|crate_impl_defs| {
+                    fps.iter().flat_map(move |fp| {
+                        crate_impl_defs.for_trait_and_self_ty(trait_, *fp).map(id_to_chalk)
+                    })
+                })
+                .collect()
+        };
 
         debug!("impls_for_trait returned {} impls", result.len());
         result
@@ -100,6 +133,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     fn associated_ty_value(&self, id: AssociatedTyValueId) -> Arc<AssociatedTyValue> {
         self.db.associated_ty_value(self.krate, id)
     }
+
     fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<Interner>> {
         vec![]
     }
@@ -115,8 +149,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         well_known_trait: rust_ir::WellKnownTrait,
     ) -> Option<chalk_ir::TraitId<Interner>> {
         let lang_attr = lang_attr_from_well_known_trait(well_known_trait);
-        let lang_items = self.db.crate_lang_items(self.krate);
-        let trait_ = match lang_items.target(lang_attr) {
+        let trait_ = match self.db.lang_item(self.krate, lang_attr.into()) {
             Some(LangItemTarget::TraitId(trait_)) => trait_,
             _ => return None,
         };
@@ -130,11 +163,34 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         self.db.program_clauses_for_chalk_env(self.krate, environment.clone())
     }
 
-    fn opaque_ty_data(
-        &self,
-        _id: chalk_ir::OpaqueTyId<Interner>,
-    ) -> Arc<rust_ir::OpaqueTyDatum<Interner>> {
-        unimplemented!()
+    fn opaque_ty_data(&self, id: chalk_ir::OpaqueTyId<Interner>) -> Arc<OpaqueTyDatum> {
+        let interned_id = crate::db::InternedOpaqueTyId::from(id);
+        let full_id = self.db.lookup_intern_impl_trait_id(interned_id);
+        let (func, idx) = match full_id {
+            crate::OpaqueTyId::ReturnTypeImplTrait(func, idx) => (func, idx),
+        };
+        let datas =
+            self.db.return_type_impl_traits(func).expect("impl trait id without impl traits");
+        let data = &datas.value.impl_traits[idx as usize];
+        let bound = OpaqueTyDatumBound {
+            bounds: make_binders(
+                data.bounds
+                    .value
+                    .iter()
+                    .cloned()
+                    .filter(|b| !b.is_error())
+                    .map(|b| b.to_chalk(self.db))
+                    .collect(),
+                1,
+            ),
+        };
+        let num_vars = datas.num_binders;
+        Arc::new(OpaqueTyDatum { opaque_ty_id: id, bound: make_binders(bound, num_vars) })
+    }
+
+    fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
+        // FIXME: actually provide the hidden type; it is relevant for auto traits
+        Ty::Unknown.to_chalk(self.db)
     }
 
     fn force_impl_for(
@@ -151,8 +207,61 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         true
     }
 
-    fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
-        Ty::Unknown.to_chalk(self.db)
+    fn closure_kind(
+        &self,
+        _closure_id: chalk_ir::ClosureId<Interner>,
+        _substs: &chalk_ir::Substitution<Interner>,
+    ) -> rust_ir::ClosureKind {
+        // Fn is the closure kind that implements all three traits
+        rust_ir::ClosureKind::Fn
+    }
+    fn closure_inputs_and_output(
+        &self,
+        _closure_id: chalk_ir::ClosureId<Interner>,
+        substs: &chalk_ir::Substitution<Interner>,
+    ) -> chalk_ir::Binders<rust_ir::FnDefInputsAndOutputDatum<Interner>> {
+        let sig_ty: Ty =
+            from_chalk(self.db, substs.at(&Interner, 0).assert_ty_ref(&Interner).clone());
+        let sig = FnSig::from_fn_ptr_substs(
+            &sig_ty.substs().expect("first closure param should be fn ptr"),
+            false,
+        );
+        let io = rust_ir::FnDefInputsAndOutputDatum {
+            argument_types: sig.params().iter().map(|ty| ty.clone().to_chalk(self.db)).collect(),
+            return_type: sig.ret().clone().to_chalk(self.db),
+        };
+        make_binders(io.shifted_in(&Interner), 0)
+    }
+    fn closure_upvars(
+        &self,
+        _closure_id: chalk_ir::ClosureId<Interner>,
+        _substs: &chalk_ir::Substitution<Interner>,
+    ) -> chalk_ir::Binders<chalk_ir::Ty<Interner>> {
+        let ty = Ty::unit().to_chalk(self.db);
+        make_binders(ty, 0)
+    }
+    fn closure_fn_substitution(
+        &self,
+        _closure_id: chalk_ir::ClosureId<Interner>,
+        _substs: &chalk_ir::Substitution<Interner>,
+    ) -> chalk_ir::Substitution<Interner> {
+        Substs::empty().to_chalk(self.db)
+    }
+
+    fn trait_name(&self, _trait_id: chalk_ir::TraitId<Interner>) -> String {
+        unimplemented!()
+    }
+    fn adt_name(&self, _struct_id: chalk_ir::AdtId<Interner>) -> String {
+        unimplemented!()
+    }
+    fn assoc_type_name(&self, _assoc_ty_id: chalk_ir::AssocTypeId<Interner>) -> String {
+        unimplemented!()
+    }
+    fn opaque_type_name(&self, _opaque_ty_id: chalk_ir::OpaqueTyId<Interner>) -> String {
+        unimplemented!()
+    }
+    fn fn_def_name(&self, _fn_def_id: chalk_ir::FnDefId<Interner>) -> String {
+        unimplemented!()
     }
 }
 
@@ -218,7 +327,7 @@ pub(crate) fn trait_datum_query(
         upstream: trait_.lookup(db.upcast()).container.module(db.upcast()).krate != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
-        // FIXME set these flags correctly
+        // FIXME: set these flags correctly
         marker: false,
         fundamental: false,
     };
@@ -240,20 +349,28 @@ pub(crate) fn trait_datum_query(
 
 fn well_known_trait_from_lang_attr(name: &str) -> Option<WellKnownTrait> {
     Some(match name {
-        "sized" => WellKnownTrait::SizedTrait,
-        "copy" => WellKnownTrait::CopyTrait,
-        "clone" => WellKnownTrait::CloneTrait,
-        "drop" => WellKnownTrait::DropTrait,
+        "sized" => WellKnownTrait::Sized,
+        "copy" => WellKnownTrait::Copy,
+        "clone" => WellKnownTrait::Clone,
+        "drop" => WellKnownTrait::Drop,
+        "fn_once" => WellKnownTrait::FnOnce,
+        "fn_mut" => WellKnownTrait::FnMut,
+        "fn" => WellKnownTrait::Fn,
+        "unsize" => WellKnownTrait::Unsize,
         _ => return None,
     })
 }
 
 fn lang_attr_from_well_known_trait(attr: WellKnownTrait) -> &'static str {
     match attr {
-        WellKnownTrait::SizedTrait => "sized",
-        WellKnownTrait::CopyTrait => "copy",
-        WellKnownTrait::CloneTrait => "clone",
-        WellKnownTrait::DropTrait => "drop",
+        WellKnownTrait::Sized => "sized",
+        WellKnownTrait::Copy => "copy",
+        WellKnownTrait::Clone => "clone",
+        WellKnownTrait::Drop => "drop",
+        WellKnownTrait::FnOnce => "fn_once",
+        WellKnownTrait::FnMut => "fn_mut",
+        WellKnownTrait::Fn => "fn",
+        WellKnownTrait::Unsize => "unsize",
     }
 }
 
@@ -277,15 +394,22 @@ pub(crate) fn struct_datum_query(
         .unwrap_or_else(Vec::new);
     let flags = rust_ir::AdtFlags {
         upstream,
-        // FIXME set fundamental flag correctly
+        // FIXME set fundamental and phantom_data flags correctly
         fundamental: false,
+        phantom_data: false,
     };
-    let struct_datum_bound = rust_ir::AdtDatumBound {
-        fields: Vec::new(), // FIXME add fields (only relevant for auto traits)
-        where_clauses,
+    // FIXME provide enum variants properly (for auto traits)
+    let variant = rust_ir::AdtVariantDatum {
+        fields: Vec::new(), // FIXME add fields (only relevant for auto traits),
+    };
+    let struct_datum_bound = rust_ir::AdtDatumBound { variants: vec![variant], where_clauses };
+    let struct_datum = StructDatum {
+        // FIXME set ADT kind
+        kind: rust_ir::AdtKind::Struct,
+        id: struct_id,
+        binders: make_binders(struct_datum_bound, num_params),
+        flags,
     };
-    let struct_datum =
-        StructDatum { id: struct_id, binders: make_binders(struct_datum_bound, num_params), flags };
     Arc::new(struct_datum)
 }
 
@@ -296,11 +420,8 @@ pub(crate) fn impl_datum_query(
 ) -> Arc<ImplDatum> {
     let _p = ra_prof::profile("impl_datum");
     debug!("impl_datum {:?}", impl_id);
-    let impl_: Impl = from_chalk(db, impl_id);
-    match impl_ {
-        Impl::ImplDef(impl_def) => impl_def_datum(db, krate, impl_id, impl_def),
-        _ => Arc::new(builtin::impl_datum(db, krate, impl_).to_chalk(db)),
-    }
+    let impl_: hir_def::ImplId = from_chalk(db, impl_id);
+    impl_def_datum(db, krate, impl_id, impl_)
 }
 
 fn impl_def_datum(
@@ -351,7 +472,7 @@ fn impl_def_datum(
             let name = &db.type_alias_data(type_alias).name;
             trait_data.associated_type_by_name(name).is_some()
         })
-        .map(|type_alias| AssocTyValue::TypeAlias(type_alias).to_chalk(db))
+        .map(|type_alias| TypeAliasAsValue(type_alias).to_chalk(db))
         .collect();
     debug!("impl_datum: {:?}", impl_datum_bound);
     let impl_datum = ImplDatum {
@@ -368,13 +489,8 @@ pub(crate) fn associated_ty_value_query(
     krate: CrateId,
     id: AssociatedTyValueId,
 ) -> Arc<AssociatedTyValue> {
-    let data: AssocTyValue = from_chalk(db, id);
-    match data {
-        AssocTyValue::TypeAlias(type_alias) => {
-            type_alias_associated_ty_value(db, krate, type_alias)
-        }
-        _ => Arc::new(builtin::associated_ty_value(db, krate, data).to_chalk(db)),
-    }
+    let type_alias: TypeAliasAsValue = from_chalk(db, id);
+    type_alias_associated_ty_value(db, krate, type_alias.0)
 }
 
 fn type_alias_associated_ty_value(
@@ -397,7 +513,7 @@ fn type_alias_associated_ty_value(
     let ty = db.ty(type_alias.into());
     let value_bound = rust_ir::AssociatedTyValueBound { ty: ty.value.to_chalk(db) };
     let value = rust_ir::AssociatedTyValue {
-        impl_id: Impl::ImplDef(impl_id).to_chalk(db),
+        impl_id: impl_id.to_chalk(db),
         associated_ty_id: assoc_ty.to_chalk(db),
         value: make_binders(value_bound, ty.num_binders),
     };
@@ -409,65 +525,65 @@ pub(crate) fn fn_def_datum_query(
     _krate: CrateId,
     fn_def_id: FnDefId,
 ) -> Arc<FnDefDatum> {
-    let callable_def: CallableDef = from_chalk(db, fn_def_id);
+    let callable_def: CallableDefId = from_chalk(db, fn_def_id);
     let generic_params = generics(db.upcast(), callable_def.into());
     let sig = db.callable_item_signature(callable_def);
     let bound_vars = Substs::bound_vars(&generic_params, DebruijnIndex::INNERMOST);
     let where_clauses = convert_where_clauses(db, callable_def.into(), &bound_vars);
     let bound = rust_ir::FnDefDatumBound {
         // Note: Chalk doesn't actually use this information yet as far as I am aware, but we provide it anyway
-        argument_types: sig.value.params().iter().map(|ty| ty.clone().to_chalk(db)).collect(),
-        return_type: sig.value.ret().clone().to_chalk(db),
+        inputs_and_output: make_binders(
+            rust_ir::FnDefInputsAndOutputDatum {
+                argument_types: sig
+                    .value
+                    .params()
+                    .iter()
+                    .map(|ty| ty.clone().to_chalk(db))
+                    .collect(),
+                return_type: sig.value.ret().clone().to_chalk(db),
+            }
+            .shifted_in(&Interner),
+            0,
+        ),
         where_clauses,
     };
-    let datum = FnDefDatum { id: fn_def_id, binders: make_binders(bound, sig.num_binders) };
+    let datum =
+        FnDefDatum { id: fn_def_id, binders: make_binders(bound, sig.num_binders), abi: () };
     Arc::new(datum)
 }
 
-impl From<AdtId> for crate::TypeCtorId {
-    fn from(struct_id: AdtId) -> Self {
-        struct_id.0
-    }
-}
-
-impl From<crate::TypeCtorId> for AdtId {
-    fn from(type_ctor_id: crate::TypeCtorId) -> Self {
-        chalk_ir::AdtId(type_ctor_id)
-    }
-}
-
-impl From<FnDefId> for crate::CallableDefId {
+impl From<FnDefId> for crate::db::InternedCallableDefId {
     fn from(fn_def_id: FnDefId) -> Self {
         InternKey::from_intern_id(fn_def_id.0)
     }
 }
 
-impl From<crate::CallableDefId> for FnDefId {
-    fn from(callable_def_id: crate::CallableDefId) -> Self {
+impl From<crate::db::InternedCallableDefId> for FnDefId {
+    fn from(callable_def_id: crate::db::InternedCallableDefId) -> Self {
         chalk_ir::FnDefId(callable_def_id.as_intern_id())
     }
 }
 
-impl From<ImplId> for crate::traits::GlobalImplId {
-    fn from(impl_id: ImplId) -> Self {
-        InternKey::from_intern_id(impl_id.0)
+impl From<OpaqueTyId> for crate::db::InternedOpaqueTyId {
+    fn from(id: OpaqueTyId) -> Self {
+        InternKey::from_intern_id(id.0)
     }
 }
 
-impl From<crate::traits::GlobalImplId> for ImplId {
-    fn from(impl_id: crate::traits::GlobalImplId) -> Self {
-        chalk_ir::ImplId(impl_id.as_intern_id())
+impl From<crate::db::InternedOpaqueTyId> for OpaqueTyId {
+    fn from(id: crate::db::InternedOpaqueTyId) -> Self {
+        chalk_ir::OpaqueTyId(id.as_intern_id())
     }
 }
 
-impl From<rust_ir::AssociatedTyValueId<Interner>> for crate::traits::AssocTyValueId {
-    fn from(id: rust_ir::AssociatedTyValueId<Interner>) -> Self {
+impl From<chalk_ir::ClosureId<Interner>> for crate::db::ClosureId {
+    fn from(id: chalk_ir::ClosureId<Interner>) -> Self {
         Self::from_intern_id(id.0)
     }
 }
 
-impl From<crate::traits::AssocTyValueId> for rust_ir::AssociatedTyValueId<Interner> {
-    fn from(assoc_ty_value_id: crate::traits::AssocTyValueId) -> Self {
-        rust_ir::AssociatedTyValueId(assoc_ty_value_id.as_intern_id())
+impl From<crate::db::ClosureId> for chalk_ir::ClosureId<Interner> {
+    fn from(id: crate::db::ClosureId) -> Self {
+        chalk_ir::ClosureId(id.as_intern_id())
     }
 }
diff --git a/crates/ra_hir_ty/src/traits/chalk/interner.rs b/crates/ra_hir_ty/src/traits/chalk/interner.rs
index e27074ba6..8d4c51a8f 100644
--- a/crates/ra_hir_ty/src/traits/chalk/interner.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/interner.rs
@@ -22,6 +22,8 @@ pub type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interne
 pub type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
 pub type FnDefId = chalk_ir::FnDefId<Interner>;
 pub type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
+pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
+pub type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
 
 impl chalk_ir::interner::Interner for Interner {
     type InternedType = Box<chalk_ir::TyData<Self>>; // FIXME use Arc?
@@ -37,9 +39,11 @@ impl chalk_ir::interner::Interner for Interner {
     type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
     type InternedVariableKinds = Vec<chalk_ir::VariableKind<Self>>;
     type InternedCanonicalVarKinds = Vec<chalk_ir::CanonicalVarKind<Self>>;
+    type InternedConstraints = Vec<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>>;
     type DefId = InternId;
-    type InternedAdtId = crate::TypeCtorId;
+    type InternedAdtId = hir_def::AdtId;
     type Identifier = TypeAliasId;
+    type FnAbi = ();
 
     fn debug_adt_id(type_kind_id: AdtId, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
         tls::with_current_program(|prog| Some(prog?.debug_struct_id(type_kind_id, fmt)))
@@ -346,6 +350,32 @@ impl chalk_ir::interner::Interner for Interner {
     ) -> &'a [chalk_ir::CanonicalVarKind<Self>] {
         &canonical_var_kinds
     }
+
+    fn intern_constraints<E>(
+        &self,
+        data: impl IntoIterator<Item = Result<chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>, E>>,
+    ) -> Result<Self::InternedConstraints, E> {
+        data.into_iter().collect()
+    }
+
+    fn constraints_data<'a>(
+        &self,
+        constraints: &'a Self::InternedConstraints,
+    ) -> &'a [chalk_ir::InEnvironment<chalk_ir::Constraint<Self>>] {
+        constraints
+    }
+    fn debug_closure_id(
+        _fn_def_id: chalk_ir::ClosureId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+    fn debug_constraints(
+        _clauses: &chalk_ir::Constraints<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
 }
 
 impl chalk_ir::interner::HasInterner for Interner {
diff --git a/crates/ra_hir_ty/src/traits/chalk/mapping.rs b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
index 5f6daf842..09d8347ca 100644
--- a/crates/ra_hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
@@ -14,10 +14,10 @@ use ra_db::salsa::InternKey;
 
 use crate::{
     db::HirDatabase,
-    primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness, Uncertain},
-    traits::{builtin, AssocTyValue, Canonical, Impl, Obligation},
-    ApplicationTy, CallableDef, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy,
-    Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
+    primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness},
+    traits::{Canonical, Obligation},
+    ApplicationTy, CallableDefId, GenericPredicate, InEnvironment, OpaqueTy, OpaqueTyId,
+    ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TyKind, TypeCtor,
 };
 
 use super::interner::*;
@@ -29,7 +29,9 @@ impl ToChalk for Ty {
         match self {
             Ty::Apply(apply_ty) => match apply_ty.ctor {
                 TypeCtor::Ref(m) => ref_to_chalk(db, m, apply_ty.parameters),
-                TypeCtor::FnPtr { num_args: _ } => {
+                TypeCtor::Array => array_to_chalk(db, apply_ty.parameters),
+                TypeCtor::FnPtr { num_args: _, is_varargs: _ } => {
+                    // FIXME: handle is_varargs
                     let substitution = apply_ty.parameters.to_chalk(db).shifted_in(&Interner);
                     chalk_ir::TyData::Function(chalk_ir::Fn { num_binders: 0, substitution })
                         .intern(&Interner)
@@ -61,14 +63,26 @@ impl ToChalk for Ty {
             Ty::Bound(idx) => chalk_ir::TyData::BoundVar(idx).intern(&Interner),
             Ty::Infer(_infer_ty) => panic!("uncanonicalized infer ty"),
             Ty::Dyn(predicates) => {
-                let where_clauses = chalk_ir::QuantifiedWhereClauses::from(
+                let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
                     &Interner,
                     predicates.iter().filter(|p| !p.is_error()).cloned().map(|p| p.to_chalk(db)),
                 );
-                let bounded_ty = chalk_ir::DynTy { bounds: make_binders(where_clauses, 1) };
+                let bounded_ty = chalk_ir::DynTy {
+                    bounds: make_binders(where_clauses, 1),
+                    lifetime: FAKE_PLACEHOLDER.to_lifetime(&Interner),
+                };
                 chalk_ir::TyData::Dyn(bounded_ty).intern(&Interner)
             }
-            Ty::Opaque(_) | Ty::Unknown => {
+            Ty::Opaque(opaque_ty) => {
+                let opaque_ty_id = opaque_ty.opaque_ty_id.to_chalk(db);
+                let substitution = opaque_ty.parameters.to_chalk(db);
+                chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
+                    opaque_ty_id,
+                    substitution,
+                }))
+                .intern(&Interner)
+            }
+            Ty::Unknown => {
                 let substitution = chalk_ir::Substitution::empty(&Interner);
                 let name = TypeName::Error;
                 chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
@@ -80,6 +94,7 @@ impl ToChalk for Ty {
             chalk_ir::TyData::Apply(apply_ty) => match apply_ty.name {
                 TypeName::Error => Ty::Unknown,
                 TypeName::Ref(m) => ref_from_chalk(db, m, apply_ty.substitution),
+                TypeName::Array => array_from_chalk(db, apply_ty.substitution),
                 _ => {
                     let ctor = from_chalk(db, apply_ty.name);
                     let parameters = from_chalk(db, apply_ty.substitution);
@@ -98,11 +113,22 @@ impl ToChalk for Ty {
                 let parameters = from_chalk(db, proj.substitution);
                 Ty::Projection(ProjectionTy { associated_ty, parameters })
             }
-            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(_)) => unimplemented!(),
-            chalk_ir::TyData::Function(chalk_ir::Fn { num_binders: _, substitution }) => {
-                let parameters: Substs = from_chalk(db, substitution);
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
+                let impl_trait_id = from_chalk(db, opaque_ty.opaque_ty_id);
+                let parameters = from_chalk(db, opaque_ty.substitution);
+                Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
+            }
+            chalk_ir::TyData::Function(chalk_ir::Fn { num_binders, substitution }) => {
+                assert_eq!(num_binders, 0);
+                let parameters: Substs = from_chalk(
+                    db,
+                    substitution.shifted_out(&Interner).expect("fn ptr should have no binders"),
+                );
                 Ty::Apply(ApplicationTy {
-                    ctor: TypeCtor::FnPtr { num_args: (parameters.len() - 1) as u16 },
+                    ctor: TypeCtor::FnPtr {
+                        num_args: (parameters.len() - 1) as u16,
+                        is_varargs: false,
+                    },
                     parameters,
                 })
             }
@@ -122,7 +148,7 @@ impl ToChalk for Ty {
     }
 }
 
-const LIFETIME_PLACEHOLDER: PlaceholderIndex =
+const FAKE_PLACEHOLDER: PlaceholderIndex =
     PlaceholderIndex { ui: UniverseIndex::ROOT, idx: usize::MAX };
 
 /// We currently don't model lifetimes, but Chalk does. So, we have to insert a
@@ -133,10 +159,10 @@ fn ref_to_chalk(
     subst: Substs,
 ) -> chalk_ir::Ty<Interner> {
     let arg = subst[0].clone().to_chalk(db);
-    let lifetime = LIFETIME_PLACEHOLDER.to_lifetime(&Interner);
+    let lifetime = FAKE_PLACEHOLDER.to_lifetime(&Interner);
     chalk_ir::ApplicationTy {
         name: TypeName::Ref(mutability.to_chalk(db)),
-        substitution: chalk_ir::Substitution::from(
+        substitution: chalk_ir::Substitution::from_iter(
             &Interner,
             vec![lifetime.cast(&Interner), arg.cast(&Interner)],
         ),
@@ -157,11 +183,40 @@ fn ref_from_chalk(
     Ty::apply(TypeCtor::Ref(from_chalk(db, mutability)), Substs(tys))
 }
 
+/// We currently don't model constants, but Chalk does. So, we have to insert a
+/// fake constant here, because Chalks built-in logic may expect it to be there.
+fn array_to_chalk(db: &dyn HirDatabase, subst: Substs) -> chalk_ir::Ty<Interner> {
+    let arg = subst[0].clone().to_chalk(db);
+    let usize_ty = chalk_ir::ApplicationTy {
+        name: TypeName::Scalar(Scalar::Uint(chalk_ir::UintTy::Usize)),
+        substitution: chalk_ir::Substitution::empty(&Interner),
+    }
+    .intern(&Interner);
+    let const_ = FAKE_PLACEHOLDER.to_const(&Interner, usize_ty);
+    chalk_ir::ApplicationTy {
+        name: TypeName::Array,
+        substitution: chalk_ir::Substitution::from_iter(
+            &Interner,
+            vec![arg.cast(&Interner), const_.cast(&Interner)],
+        ),
+    }
+    .intern(&Interner)
+}
+
+/// Here we remove the const from the type we got from Chalk.
+fn array_from_chalk(db: &dyn HirDatabase, subst: chalk_ir::Substitution<Interner>) -> Ty {
+    let tys = subst
+        .iter(&Interner)
+        .filter_map(|p| Some(from_chalk(db, p.ty(&Interner)?.clone())))
+        .collect();
+    Ty::apply(TypeCtor::Array, Substs(tys))
+}
+
 impl ToChalk for Substs {
     type Chalk = chalk_ir::Substitution<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Substitution<Interner> {
-        chalk_ir::Substitution::from(&Interner, self.iter().map(|ty| ty.clone().to_chalk(db)))
+        chalk_ir::Substitution::from_iter(&Interner, self.iter().map(|ty| ty.clone().to_chalk(db)))
     }
 
     fn from_chalk(db: &dyn HirDatabase, parameters: chalk_ir::Substitution<Interner>) -> Substs {
@@ -204,6 +259,21 @@ impl ToChalk for hir_def::TraitId {
     }
 }
 
+impl ToChalk for OpaqueTyId {
+    type Chalk = chalk_ir::OpaqueTyId<Interner>;
+
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::OpaqueTyId<Interner> {
+        db.intern_impl_trait_id(self).into()
+    }
+
+    fn from_chalk(
+        db: &dyn HirDatabase,
+        opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
+    ) -> OpaqueTyId {
+        db.lookup_intern_impl_trait_id(opaque_ty_id.into())
+    }
+}
+
 impl ToChalk for TypeCtor {
     type Chalk = TypeName<Interner>;
 
@@ -214,19 +284,25 @@ impl ToChalk for TypeCtor {
                 TypeName::AssociatedType(type_id)
             }
 
+            TypeCtor::OpaqueType(impl_trait_id) => {
+                let id = impl_trait_id.to_chalk(db);
+                TypeName::OpaqueType(id)
+            }
+
             TypeCtor::Bool => TypeName::Scalar(Scalar::Bool),
             TypeCtor::Char => TypeName::Scalar(Scalar::Char),
-            TypeCtor::Int(Uncertain::Known(int_ty)) => TypeName::Scalar(int_ty_to_chalk(int_ty)),
-            TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X32 })) => {
+            TypeCtor::Int(int_ty) => TypeName::Scalar(int_ty_to_chalk(int_ty)),
+            TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 }) => {
                 TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32))
             }
-            TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X64 })) => {
+            TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 }) => {
                 TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64))
             }
 
             TypeCtor::Tuple { cardinality } => TypeName::Tuple(cardinality.into()),
             TypeCtor::RawPtr(mutability) => TypeName::Raw(mutability.to_chalk(db)),
             TypeCtor::Slice => TypeName::Slice,
+            TypeCtor::Array => TypeName::Array,
             TypeCtor::Ref(mutability) => TypeName::Ref(mutability.to_chalk(db)),
             TypeCtor::Str => TypeName::Str,
             TypeCtor::FnDef(callable_def) => {
@@ -235,40 +311,44 @@ impl ToChalk for TypeCtor {
             }
             TypeCtor::Never => TypeName::Never,
 
-            TypeCtor::Int(Uncertain::Unknown)
-            | TypeCtor::Float(Uncertain::Unknown)
-            | TypeCtor::Adt(_)
-            | TypeCtor::Array
-            | TypeCtor::FnPtr { .. }
-            | TypeCtor::Closure { .. } => {
-                // other TypeCtors get interned and turned into a chalk StructId
-                let struct_id = db.intern_type_ctor(self).into();
-                TypeName::Adt(struct_id)
+            TypeCtor::Closure { def, expr } => {
+                let closure_id = db.intern_closure((def, expr));
+                TypeName::Closure(closure_id.into())
+            }
+
+            TypeCtor::Adt(adt_id) => TypeName::Adt(chalk_ir::AdtId(adt_id)),
+
+            TypeCtor::FnPtr { .. } => {
+                // This should not be reached, since Chalk doesn't represent
+                // function pointers with TypeName
+                unreachable!()
             }
         }
     }
 
     fn from_chalk(db: &dyn HirDatabase, type_name: TypeName<Interner>) -> TypeCtor {
         match type_name {
-            TypeName::Adt(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
+            TypeName::Adt(struct_id) => TypeCtor::Adt(struct_id.0),
             TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
-            TypeName::OpaqueType(_) => unreachable!(),
+            TypeName::OpaqueType(opaque_type_id) => {
+                TypeCtor::OpaqueType(from_chalk(db, opaque_type_id))
+            }
 
             TypeName::Scalar(Scalar::Bool) => TypeCtor::Bool,
             TypeName::Scalar(Scalar::Char) => TypeCtor::Char,
-            TypeName::Scalar(Scalar::Int(int_ty)) => TypeCtor::Int(Uncertain::Known(IntTy {
+            TypeName::Scalar(Scalar::Int(int_ty)) => TypeCtor::Int(IntTy {
                 signedness: Signedness::Signed,
                 bitness: bitness_from_chalk_int(int_ty),
-            })),
-            TypeName::Scalar(Scalar::Uint(uint_ty)) => TypeCtor::Int(Uncertain::Known(IntTy {
+            }),
+            TypeName::Scalar(Scalar::Uint(uint_ty)) => TypeCtor::Int(IntTy {
                 signedness: Signedness::Unsigned,
                 bitness: bitness_from_chalk_uint(uint_ty),
-            })),
+            }),
             TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32)) => {
-                TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X32 }))
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 })
             }
             TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64)) => {
-                TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X64 }))
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 })
             }
             TypeName::Tuple(cardinality) => TypeCtor::Tuple { cardinality: cardinality as u16 },
             TypeName::Raw(mutability) => TypeCtor::RawPtr(from_chalk(db, mutability)),
@@ -281,8 +361,15 @@ impl ToChalk for TypeCtor {
                 let callable_def = from_chalk(db, fn_def_id);
                 TypeCtor::FnDef(callable_def)
             }
+            TypeName::Array => TypeCtor::Array,
 
-            TypeName::Array | TypeName::Error => {
+            TypeName::Closure(id) => {
+                let id: crate::db::ClosureId = id.into();
+                let (def, expr) = db.lookup_intern_closure(id);
+                TypeCtor::Closure { def, expr }
+            }
+
+            TypeName::Error => {
                 // this should not be reached, since we don't represent TypeName::Error with TypeCtor
                 unreachable!()
             }
@@ -355,26 +442,26 @@ impl ToChalk for Mutability {
     }
 }
 
-impl ToChalk for Impl {
+impl ToChalk for hir_def::ImplId {
     type Chalk = ImplId;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> ImplId {
-        db.intern_chalk_impl(self).into()
+    fn to_chalk(self, _db: &dyn HirDatabase) -> ImplId {
+        chalk_ir::ImplId(self.as_intern_id())
     }
 
-    fn from_chalk(db: &dyn HirDatabase, impl_id: ImplId) -> Impl {
-        db.lookup_intern_chalk_impl(impl_id.into())
+    fn from_chalk(_db: &dyn HirDatabase, impl_id: ImplId) -> hir_def::ImplId {
+        InternKey::from_intern_id(impl_id.0)
     }
 }
 
-impl ToChalk for CallableDef {
+impl ToChalk for CallableDefId {
     type Chalk = FnDefId;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> FnDefId {
         db.intern_callable_def(self).into()
     }
 
-    fn from_chalk(db: &dyn HirDatabase, fn_def_id: FnDefId) -> CallableDef {
+    fn from_chalk(db: &dyn HirDatabase, fn_def_id: FnDefId) -> CallableDefId {
         db.lookup_intern_callable_def(fn_def_id.into())
     }
 }
@@ -391,15 +478,20 @@ impl ToChalk for TypeAliasId {
     }
 }
 
-impl ToChalk for AssocTyValue {
+pub struct TypeAliasAsValue(pub TypeAliasId);
+
+impl ToChalk for TypeAliasAsValue {
     type Chalk = AssociatedTyValueId;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> AssociatedTyValueId {
-        db.intern_assoc_ty_value(self).into()
+    fn to_chalk(self, _db: &dyn HirDatabase) -> AssociatedTyValueId {
+        rust_ir::AssociatedTyValueId(self.0.as_intern_id())
     }
 
-    fn from_chalk(db: &dyn HirDatabase, assoc_ty_value_id: AssociatedTyValueId) -> AssocTyValue {
-        db.lookup_intern_assoc_ty_value(assoc_ty_value_id.into())
+    fn from_chalk(
+        _db: &dyn HirDatabase,
+        assoc_ty_value_id: AssociatedTyValueId,
+    ) -> TypeAliasAsValue {
+        TypeAliasAsValue(TypeAliasId::from_intern_id(assoc_ty_value_id.0))
     }
 }
 
@@ -447,6 +539,16 @@ impl ToChalk for GenericPredicate {
                 let ty = from_chalk(db, projection_eq.ty);
                 GenericPredicate::Projection(ProjectionPredicate { projection_ty, ty })
             }
+
+            chalk_ir::WhereClause::LifetimeOutlives(_) => {
+                // we shouldn't get these from Chalk
+                panic!("encountered LifetimeOutlives from Chalk")
+            }
+
+            chalk_ir::WhereClause::TypeOutlives(_) => {
+                // we shouldn't get these from Chalk
+                panic!("encountered TypeOutlives from Chalk")
+            }
         }
     }
 }
@@ -510,22 +612,42 @@ where
     type Chalk = chalk_ir::Canonical<T::Chalk>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
-        let parameter = chalk_ir::CanonicalVarKind::new(
-            chalk_ir::VariableKind::Ty(chalk_ir::TyKind::General),
-            chalk_ir::UniverseIndex::ROOT,
-        );
+        let kinds = self
+            .kinds
+            .iter()
+            .map(|k| match k {
+                TyKind::General => chalk_ir::TyKind::General,
+                TyKind::Integer => chalk_ir::TyKind::Integer,
+                TyKind::Float => chalk_ir::TyKind::Float,
+            })
+            .map(|tk| {
+                chalk_ir::CanonicalVarKind::new(
+                    chalk_ir::VariableKind::Ty(tk),
+                    chalk_ir::UniverseIndex::ROOT,
+                )
+            });
         let value = self.value.to_chalk(db);
         chalk_ir::Canonical {
             value,
-            binders: chalk_ir::CanonicalVarKinds::from(&Interner, vec![parameter; self.num_vars]),
+            binders: chalk_ir::CanonicalVarKinds::from_iter(&Interner, kinds),
         }
     }
 
     fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
-        Canonical {
-            num_vars: canonical.binders.len(&Interner),
-            value: from_chalk(db, canonical.value),
-        }
+        let kinds = canonical
+            .binders
+            .iter(&Interner)
+            .map(|k| match k.kind {
+                chalk_ir::VariableKind::Ty(tk) => match tk {
+                    chalk_ir::TyKind::General => TyKind::General,
+                    chalk_ir::TyKind::Integer => TyKind::Integer,
+                    chalk_ir::TyKind::Float => TyKind::Float,
+                },
+                chalk_ir::VariableKind::Lifetime => panic!("unexpected lifetime from Chalk"),
+                chalk_ir::VariableKind::Const(_) => panic!("unexpected const from Chalk"),
+            })
+            .collect();
+        Canonical { kinds, value: from_chalk(db, canonical.value) }
     }
 }
 
@@ -578,58 +700,12 @@ where
     }
 }
 
-impl ToChalk for builtin::BuiltinImplData {
-    type Chalk = ImplDatum;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> ImplDatum {
-        let impl_type = rust_ir::ImplType::External;
-        let where_clauses = self.where_clauses.into_iter().map(|w| w.to_chalk(db)).collect();
-
-        let impl_datum_bound =
-            rust_ir::ImplDatumBound { trait_ref: self.trait_ref.to_chalk(db), where_clauses };
-        let associated_ty_value_ids =
-            self.assoc_ty_values.into_iter().map(|v| v.to_chalk(db)).collect();
-        rust_ir::ImplDatum {
-            binders: make_binders(impl_datum_bound, self.num_vars),
-            impl_type,
-            polarity: rust_ir::Polarity::Positive,
-            associated_ty_value_ids,
-        }
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, _data: ImplDatum) -> Self {
-        unimplemented!()
-    }
-}
-
-impl ToChalk for builtin::BuiltinImplAssocTyValueData {
-    type Chalk = AssociatedTyValue;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> AssociatedTyValue {
-        let ty = self.value.to_chalk(db);
-        let value_bound = rust_ir::AssociatedTyValueBound { ty };
-
-        rust_ir::AssociatedTyValue {
-            associated_ty_id: self.assoc_ty_id.to_chalk(db),
-            impl_id: self.impl_.to_chalk(db),
-            value: make_binders(value_bound, self.num_vars),
-        }
-    }
-
-    fn from_chalk(
-        _db: &dyn HirDatabase,
-        _data: AssociatedTyValue,
-    ) -> builtin::BuiltinImplAssocTyValueData {
-        unimplemented!()
-    }
-}
-
 pub(super) fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T>
 where
     T: HasInterner<Interner = Interner>,
 {
     chalk_ir::Binders::new(
-        chalk_ir::VariableKinds::from(
+        chalk_ir::VariableKinds::from_iter(
             &Interner,
             std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyKind::General)).take(num_vars),
         ),
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index d88828c7c..db915625c 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -5,12 +5,12 @@ use chalk_ir::{AliasTy, GenericArg, Goal, Goals, Lifetime, ProgramClauseImplicat
 use itertools::Itertools;
 
 use super::{from_chalk, Interner};
-use crate::{db::HirDatabase, CallableDef, TypeCtor};
+use crate::{db::HirDatabase, CallableDefId, TypeCtor};
 use hir_def::{AdtId, AssocContainerId, DefWithBodyId, Lookup, TypeAliasId};
 
 pub use unsafe_tls::{set_current_program, with_current_program};
 
-pub struct DebugContext<'a>(&'a (dyn HirDatabase + 'a));
+pub struct DebugContext<'a>(&'a dyn HirDatabase);
 
 impl DebugContext<'_> {
     pub fn debug_struct_id(
@@ -38,16 +38,16 @@ impl DebugContext<'_> {
             }
             TypeCtor::FnDef(def) => {
                 let name = match def {
-                    CallableDef::FunctionId(ff) => self.0.function_data(ff).name.clone(),
-                    CallableDef::StructId(s) => self.0.struct_data(s).name.clone(),
-                    CallableDef::EnumVariantId(e) => {
+                    CallableDefId::FunctionId(ff) => self.0.function_data(ff).name.clone(),
+                    CallableDefId::StructId(s) => self.0.struct_data(s).name.clone(),
+                    CallableDefId::EnumVariantId(e) => {
                         let enum_data = self.0.enum_data(e.parent);
                         enum_data.variants[e.local_id].name.clone()
                     }
                 };
                 match def {
-                    CallableDef::FunctionId(_) => write!(f, "{{fn {}}}", name)?,
-                    CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+                    CallableDefId::FunctionId(_) => write!(f, "{{fn {}}}", name)?,
+                    CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {
                         write!(f, "{{ctor {}}}", name)?
                     }
                 }
@@ -69,6 +69,11 @@ impl DebugContext<'_> {
                 let name = self.0.type_alias_data(type_alias).name.clone();
                 write!(f, "{}::{}", trait_name, name)?;
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => match opaque_ty_id {
+                crate::OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                    write!(f, "{{impl trait {} of {:?}}}", idx, func)?;
+                }
+            },
             TypeCtor::Closure { def, expr } => {
                 write!(f, "{{closure {:?} in ", expr.into_raw())?;
                 match def {
@@ -152,7 +157,7 @@ impl DebugContext<'_> {
             _ => panic!("associated type not in trait"),
         };
         let trait_data = self.0.trait_data(trait_);
-        let params = projection_ty.substitution.parameters(&Interner);
+        let params = projection_ty.substitution.as_slice(&Interner);
         write!(fmt, "<{:?} as {}", &params[0], trait_data.name,)?;
         if params.len() > 1 {
             write!(
@@ -250,18 +255,18 @@ impl DebugContext<'_> {
         fn_def_id: chalk_ir::FnDefId<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        let def: CallableDef = from_chalk(self.0, fn_def_id);
+        let def: CallableDefId = from_chalk(self.0, fn_def_id);
         let name = match def {
-            CallableDef::FunctionId(ff) => self.0.function_data(ff).name.clone(),
-            CallableDef::StructId(s) => self.0.struct_data(s).name.clone(),
-            CallableDef::EnumVariantId(e) => {
+            CallableDefId::FunctionId(ff) => self.0.function_data(ff).name.clone(),
+            CallableDefId::StructId(s) => self.0.struct_data(s).name.clone(),
+            CallableDefId::EnumVariantId(e) => {
                 let enum_data = self.0.enum_data(e.parent);
                 enum_data.variants[e.local_id].name.clone()
             }
         };
         match def {
-            CallableDef::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
-            CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
+            CallableDefId::FunctionId(_) => write!(fmt, "{{fn {}}}", name),
+            CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {
                 write!(fmt, "{{ctor {}}}", name)
             }
         }
diff --git a/crates/ra_hir_ty/src/utils.rs b/crates/ra_hir_ty/src/utils.rs
index f98350bf9..e3e244268 100644
--- a/crates/ra_hir_ty/src/utils.rs
+++ b/crates/ra_hir_ty/src/utils.rs
@@ -110,46 +110,15 @@ pub(super) fn all_super_trait_refs(db: &dyn HirDatabase, trait_ref: TraitRef) ->
     result
 }
 
-/// Finds a path from a trait to one of its super traits. Returns an empty
-/// vector if there is no path.
-pub(super) fn find_super_trait_path(
-    db: &dyn DefDatabase,
-    trait_: TraitId,
-    super_trait: TraitId,
-) -> Vec<TraitId> {
-    let mut result = Vec::with_capacity(2);
-    result.push(trait_);
-    return if go(db, super_trait, &mut result) { result } else { Vec::new() };
-
-    fn go(db: &dyn DefDatabase, super_trait: TraitId, path: &mut Vec<TraitId>) -> bool {
-        let trait_ = *path.last().unwrap();
-        if trait_ == super_trait {
-            return true;
-        }
-
-        for tt in direct_super_traits(db, trait_) {
-            if path.contains(&tt) {
-                continue;
-            }
-            path.push(tt);
-            if go(db, super_trait, path) {
-                return true;
-            } else {
-                path.pop();
-            }
-        }
-        false
-    }
-}
-
 pub(super) fn associated_type_by_name_including_super_traits(
-    db: &dyn DefDatabase,
-    trait_: TraitId,
+    db: &dyn HirDatabase,
+    trait_ref: TraitRef,
     name: &Name,
-) -> Option<TypeAliasId> {
-    all_super_traits(db, trait_)
-        .into_iter()
-        .find_map(|t| db.trait_data(t).associated_type_by_name(name))
+) -> Option<(TraitRef, TypeAliasId)> {
+    all_super_trait_refs(db, trait_ref).into_iter().find_map(|t| {
+        let assoc_type = db.trait_data(t.trait_).associated_type_by_name(name)?;
+        Some((t, assoc_type))
+    })
 }
 
 pub(super) fn variant_data(db: &dyn DefDatabase, var: VariantId) -> Arc<VariantData> {
@@ -176,6 +145,7 @@ pub(crate) fn generics(db: &dyn DefDatabase, def: GenericDefId) -> Generics {
     Generics { def, params: db.generic_params(def), parent_generics }
 }
 
+#[derive(Debug)]
 pub(crate) struct Generics {
     def: GenericDefId,
     pub(crate) params: Arc<GenericParams>,
diff --git a/crates/ra_ide/Cargo.toml b/crates/ra_ide/Cargo.toml
index 05c940605..6f8107491 100644
--- a/crates/ra_ide/Cargo.toml
+++ b/crates/ra_ide/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_ide"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -29,10 +30,11 @@ ra_fmt = { path = "../ra_fmt" }
 ra_prof = { path = "../ra_prof" }
 test_utils = { path = "../test_utils" }
 ra_assists = { path = "../ra_assists" }
+ra_ssr = { path = "../ra_ssr" }
 
 # ra_ide should depend only on the top-level `hir` package. if you need
 # something from some `hir_xxx` subpackage, reexport the API via `hir`.
 hir = { path = "../ra_hir", package = "ra_hir" }
 
 [dev-dependencies]
-insta = "0.16.0"
+expect = { path = "../expect" }
diff --git a/crates/ra_ide/src/call_hierarchy.rs b/crates/ra_ide/src/call_hierarchy.rs
index defd8176f..cb7e62cd6 100644
--- a/crates/ra_ide/src/call_hierarchy.rs
+++ b/crates/ra_ide/src/call_hierarchy.rs
@@ -39,10 +39,11 @@ pub(crate) fn call_hierarchy(
 
 pub(crate) fn incoming_calls(db: &RootDatabase, position: FilePosition) -> Option<Vec<CallItem>> {
     let sema = Semantics::new(db);
+
     // 1. Find all refs
     // 2. Loop through refs and determine unique fndef. This will become our `from: CallHierarchyItem,` in the reply.
     // 3. Add ranges relative to the start of the fndef.
-    let refs = references::find_all_refs(db, position, None)?;
+    let refs = references::find_all_refs(&sema, position, None)?;
 
     let mut calls = CallLocations::default();
 
@@ -96,7 +97,7 @@ pub(crate) fn outgoing_calls(db: &RootDatabase, position: FilePosition) -> Optio
                     //FIXME: Type::as_callable is broken
                     let callable_def = sema.type_of_expr(&expr.expr()?)?.as_callable()?;
                     match callable_def {
-                        hir::CallableDef::FunctionId(it) => {
+                        hir::CallableDefId::FunctionId(it) => {
                             let fn_def: hir::Function = it.into();
                             let nav = fn_def.to_nav(db);
                             Some(nav)
@@ -145,12 +146,12 @@ mod tests {
     use crate::mock_analysis::analysis_and_position;
 
     fn check_hierarchy(
-        fixture: &str,
+        ra_fixture: &str,
         expected: &str,
         expected_incoming: &[&str],
         expected_outgoing: &[&str],
     ) {
-        let (analysis, pos) = analysis_and_position(fixture);
+        let (analysis, pos) = analysis_and_position(ra_fixture);
 
         let mut navs = analysis.call_hierarchy(pos).unwrap().unwrap().info;
         assert_eq!(navs.len(), 1);
@@ -177,12 +178,12 @@ mod tests {
     fn test_call_hierarchy_on_ref() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn callee() {}
-            fn caller() {
-                call<|>ee();
-            }
-            "#,
+//- /lib.rs
+fn callee() {}
+fn caller() {
+    call<|>ee();
+}
+"#,
             "callee FN_DEF FileId(1) 0..14 3..9",
             &["caller FN_DEF FileId(1) 15..44 18..24 : [33..39]"],
             &[],
@@ -193,12 +194,12 @@ mod tests {
     fn test_call_hierarchy_on_def() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn call<|>ee() {}
-            fn caller() {
-                callee();
-            }
-            "#,
+//- /lib.rs
+fn call<|>ee() {}
+fn caller() {
+    callee();
+}
+"#,
             "callee FN_DEF FileId(1) 0..14 3..9",
             &["caller FN_DEF FileId(1) 15..44 18..24 : [33..39]"],
             &[],
@@ -209,13 +210,13 @@ mod tests {
     fn test_call_hierarchy_in_same_fn() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn callee() {}
-            fn caller() {
-                call<|>ee();
-                callee();
-            }
-            "#,
+//- /lib.rs
+fn callee() {}
+fn caller() {
+    call<|>ee();
+    callee();
+}
+"#,
             "callee FN_DEF FileId(1) 0..14 3..9",
             &["caller FN_DEF FileId(1) 15..58 18..24 : [33..39, 47..53]"],
             &[],
@@ -226,20 +227,20 @@ mod tests {
     fn test_call_hierarchy_in_different_fn() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn callee() {}
-            fn caller1() {
-                call<|>ee();
-            }
+//- /lib.rs
+fn callee() {}
+fn caller1() {
+    call<|>ee();
+}
 
-            fn caller2() {
-                callee();
-            }
-            "#,
+fn caller2() {
+    callee();
+}
+"#,
             "callee FN_DEF FileId(1) 0..14 3..9",
             &[
                 "caller1 FN_DEF FileId(1) 15..45 18..25 : [34..40]",
-                "caller2 FN_DEF FileId(1) 46..76 49..56 : [65..71]",
+                "caller2 FN_DEF FileId(1) 47..77 50..57 : [66..72]",
             ],
             &[],
         );
@@ -249,26 +250,26 @@ mod tests {
     fn test_call_hierarchy_in_tests_mod() {
         check_hierarchy(
             r#"
-            //- /lib.rs cfg:test
-            fn callee() {}
-            fn caller1() {
-                call<|>ee();
-            }
+//- /lib.rs cfg:test
+fn callee() {}
+fn caller1() {
+    call<|>ee();
+}
 
-            #[cfg(test)]
-            mod tests {
-                use super::*;
+#[cfg(test)]
+mod tests {
+    use super::*;
 
-                #[test]
-                fn test_caller() {
-                    callee();
-                }
-            }
-            "#,
+    #[test]
+    fn test_caller() {
+        callee();
+    }
+}
+"#,
             "callee FN_DEF FileId(1) 0..14 3..9",
             &[
                 "caller1 FN_DEF FileId(1) 15..45 18..25 : [34..40]",
-                "test_caller FN_DEF FileId(1) 93..147 108..119 : [132..138]",
+                "test_caller FN_DEF FileId(1) 95..149 110..121 : [134..140]",
             ],
             &[],
         );
@@ -278,19 +279,19 @@ mod tests {
     fn test_call_hierarchy_in_different_files() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            mod foo;
-            use foo::callee;
+//- /lib.rs
+mod foo;
+use foo::callee;
 
-            fn caller() {
-                call<|>ee();
-            }
+fn caller() {
+    call<|>ee();
+}
 
-            //- /foo/mod.rs
-            pub fn callee() {}
-            "#,
+//- /foo/mod.rs
+pub fn callee() {}
+"#,
             "callee FN_DEF FileId(2) 0..18 7..13",
-            &["caller FN_DEF FileId(1) 26..55 29..35 : [44..50]"],
+            &["caller FN_DEF FileId(1) 27..56 30..36 : [45..51]"],
             &[],
         );
     }
@@ -299,13 +300,13 @@ mod tests {
     fn test_call_hierarchy_outgoing() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn callee() {}
-            fn call<|>er() {
-                callee();
-                callee();
-            }
-            "#,
+//- /lib.rs
+fn callee() {}
+fn call<|>er() {
+    callee();
+    callee();
+}
+"#,
             "caller FN_DEF FileId(1) 15..58 18..24",
             &[],
             &["callee FN_DEF FileId(1) 0..14 3..9 : [33..39, 47..53]"],
@@ -316,20 +317,20 @@ mod tests {
     fn test_call_hierarchy_outgoing_in_different_files() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            mod foo;
-            use foo::callee;
+//- /lib.rs
+mod foo;
+use foo::callee;
 
-            fn call<|>er() {
-                callee();
-            }
+fn call<|>er() {
+    callee();
+}
 
-            //- /foo/mod.rs
-            pub fn callee() {}
-            "#,
-            "caller FN_DEF FileId(1) 26..55 29..35",
+//- /foo/mod.rs
+pub fn callee() {}
+"#,
+            "caller FN_DEF FileId(1) 27..56 30..36",
             &[],
-            &["callee FN_DEF FileId(2) 0..18 7..13 : [44..50]"],
+            &["callee FN_DEF FileId(2) 0..18 7..13 : [45..51]"],
         );
     }
 
@@ -337,22 +338,59 @@ mod tests {
     fn test_call_hierarchy_incoming_outgoing() {
         check_hierarchy(
             r#"
-            //- /lib.rs
-            fn caller1() {
-                call<|>er2();
-            }
+//- /lib.rs
+fn caller1() {
+    call<|>er2();
+}
 
-            fn caller2() {
-                caller3();
-            }
+fn caller2() {
+    caller3();
+}
 
-            fn caller3() {
+fn caller3() {
 
-            }
-            "#,
-            "caller2 FN_DEF FileId(1) 32..63 35..42",
+}
+"#,
+            "caller2 FN_DEF FileId(1) 33..64 36..43",
             &["caller1 FN_DEF FileId(1) 0..31 3..10 : [19..26]"],
-            &["caller3 FN_DEF FileId(1) 64..80 67..74 : [51..58]"],
+            &["caller3 FN_DEF FileId(1) 66..83 69..76 : [52..59]"],
+        );
+    }
+
+    #[test]
+    fn test_call_hierarchy_issue_5103() {
+        check_hierarchy(
+            r#"
+fn a() {
+    b()
+}
+
+fn b() {}
+
+fn main() {
+    a<|>()
+}
+"#,
+            "a FN_DEF FileId(1) 0..18 3..4",
+            &["main FN_DEF FileId(1) 31..52 34..38 : [47..48]"],
+            &["b FN_DEF FileId(1) 20..29 23..24 : [13..14]"],
+        );
+
+        check_hierarchy(
+            r#"
+fn a() {
+    b<|>()
+}
+
+fn b() {}
+
+fn main() {
+    a()
+}
+"#,
+            "b FN_DEF FileId(1) 20..29 23..24",
+            &["a FN_DEF FileId(1) 0..18 3..4 : [13..14]"],
+            &[],
         );
     }
 }
diff --git a/crates/ra_ide/src/call_info.rs b/crates/ra_ide/src/call_info.rs
index aa039e6fc..1fe1c21de 100644
--- a/crates/ra_ide/src/call_info.rs
+++ b/crates/ra_ide/src/call_info.rs
@@ -7,7 +7,15 @@ use ra_syntax::{
 };
 use test_utils::mark;
 
-use crate::{CallInfo, FilePosition, FunctionSignature};
+use crate::{FilePosition, FunctionSignature};
+
+/// Contains information about a call site. Specifically the
+/// `FunctionSignature`and current parameter.
+#[derive(Debug)]
+pub struct CallInfo {
+    pub signature: FunctionSignature,
+    pub active_parameter: Option<usize>,
+}
 
 /// Computes parameter information for the given call expression.
 pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<CallInfo> {
@@ -40,43 +48,40 @@ fn call_info_for_token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Op
     // Find the calling expression and it's NameRef
     let calling_node = FnCallNode::with_node(&token.parent())?;
 
-    let (mut call_info, has_self) = match &calling_node {
+    let signature = match &calling_node {
         FnCallNode::CallExpr(call) => {
             //FIXME: Type::as_callable is broken
             let callable_def = sema.type_of_expr(&call.expr()?)?.as_callable()?;
             match callable_def {
-                hir::CallableDef::FunctionId(it) => {
+                hir::CallableDefId::FunctionId(it) => {
                     let fn_def = it.into();
-                    (CallInfo::with_fn(sema.db, fn_def), fn_def.has_self_param(sema.db))
+                    FunctionSignature::from_hir(sema.db, fn_def)
                 }
-                hir::CallableDef::StructId(it) => {
-                    (CallInfo::with_struct(sema.db, it.into())?, false)
+                hir::CallableDefId::StructId(it) => {
+                    FunctionSignature::from_struct(sema.db, it.into())?
                 }
-                hir::CallableDef::EnumVariantId(it) => {
-                    (CallInfo::with_enum_variant(sema.db, it.into())?, false)
+                hir::CallableDefId::EnumVariantId(it) => {
+                    FunctionSignature::from_enum_variant(sema.db, it.into())?
                 }
             }
         }
         FnCallNode::MethodCallExpr(method_call) => {
             let function = sema.resolve_method_call(&method_call)?;
-            (CallInfo::with_fn(sema.db, function), function.has_self_param(sema.db))
+            FunctionSignature::from_hir(sema.db, function)
         }
         FnCallNode::MacroCallExpr(macro_call) => {
             let macro_def = sema.resolve_macro_call(&macro_call)?;
-            (CallInfo::with_macro(sema.db, macro_def)?, false)
+            FunctionSignature::from_macro(sema.db, macro_def)?
         }
     };
 
     // If we have a calling expression let's find which argument we are on
-    let num_params = call_info.parameters().len();
+    let num_params = signature.parameters.len();
 
-    match num_params {
-        0 => (),
-        1 => {
-            if !has_self {
-                call_info.active_parameter = Some(0);
-            }
-        }
+    let active_parameter = match num_params {
+        0 => None,
+        1 if signature.has_self_param => None,
+        1 => Some(0),
         _ => {
             if let Some(arg_list) = calling_node.arg_list() {
                 // Number of arguments specified at the call site
@@ -93,22 +98,24 @@ fn call_info_for_token(sema: &Semantics<RootDatabase>, token: SyntaxToken) -> Op
                     arg_list
                         .args()
                         .take_while(|arg| {
-                            arg.syntax().text_range().end() < token.text_range().start()
+                            arg.syntax().text_range().end() <= token.text_range().start()
                         })
                         .count(),
                 );
 
                 // If we are in a method account for `self`
-                if has_self {
+                if signature.has_self_param {
                     param += 1;
                 }
 
-                call_info.active_parameter = Some(param);
+                Some(param)
+            } else {
+                None
             }
         }
-    }
+    };
 
-    Some(call_info)
+    Some(CallInfo { signature, active_parameter })
 }
 
 #[derive(Debug)]
@@ -181,201 +188,192 @@ impl CallInfo {
         let res = ActiveParameter { ty, name };
         Some(res)
     }
-
-    fn with_fn(db: &RootDatabase, function: hir::Function) -> Self {
-        let signature = FunctionSignature::from_hir(db, function);
-
-        CallInfo { signature, active_parameter: None }
-    }
-
-    fn with_struct(db: &RootDatabase, st: hir::Struct) -> Option<Self> {
-        let signature = FunctionSignature::from_struct(db, st)?;
-
-        Some(CallInfo { signature, active_parameter: None })
-    }
-
-    fn with_enum_variant(db: &RootDatabase, variant: hir::EnumVariant) -> Option<Self> {
-        let signature = FunctionSignature::from_enum_variant(db, variant)?;
-
-        Some(CallInfo { signature, active_parameter: None })
-    }
-
-    fn with_macro(db: &RootDatabase, macro_def: hir::MacroDef) -> Option<Self> {
-        let signature = FunctionSignature::from_macro(db, macro_def)?;
-
-        Some(CallInfo { signature, active_parameter: None })
-    }
-
-    fn parameters(&self) -> &[String] {
-        &self.signature.parameters
-    }
 }
 
 #[cfg(test)]
 mod tests {
+    use expect::{expect, Expect};
     use test_utils::mark;
 
-    use crate::mock_analysis::single_file_with_position;
-
-    use super::*;
-
-    // These are only used when testing
-    impl CallInfo {
-        fn doc(&self) -> Option<hir::Documentation> {
-            self.signature.doc.clone()
-        }
-
-        fn label(&self) -> String {
-            self.signature.to_string()
-        }
-    }
-
-    fn call_info_helper(text: &str) -> Option<CallInfo> {
-        let (analysis, position) = single_file_with_position(text);
-        analysis.call_info(position).unwrap()
-    }
-
-    fn call_info(text: &str) -> CallInfo {
-        let info = call_info_helper(text);
-        assert!(info.is_some());
-        info.unwrap()
-    }
+    use crate::mock_analysis::analysis_and_position;
 
-    fn no_call_info(text: &str) {
-        let info = call_info_helper(text);
-        assert!(info.is_none());
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let call_info = analysis.call_info(position).unwrap();
+        let actual = match call_info {
+            Some(call_info) => {
+                let docs = match &call_info.signature.doc {
+                    None => "".to_string(),
+                    Some(docs) => format!("{}\n------\n", docs.as_str()),
+                };
+                let params = call_info
+                    .signature
+                    .parameters
+                    .iter()
+                    .enumerate()
+                    .map(|(i, param)| {
+                        if Some(i) == call_info.active_parameter {
+                            format!("<{}>", param)
+                        } else {
+                            param.clone()
+                        }
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                format!("{}{}\n({})\n", docs, call_info.signature, params)
+            }
+            None => String::new(),
+        };
+        expect.assert_eq(&actual);
     }
 
     #[test]
-    fn test_fn_signature_two_args_firstx() {
-        let info = call_info(
-            r#"fn foo(x: u32, y: u32) -> u32 {x + y}
-fn bar() { foo(<|>3, ); }"#,
+    fn test_fn_signature_two_args() {
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["x: u32", "y: u32"]);
-        assert_eq!(info.active_parameter, Some(0));
-    }
-
-    #[test]
-    fn test_fn_signature_two_args_second() {
-        let info = call_info(
-            r#"fn foo(x: u32, y: u32) -> u32 {x + y}
-fn bar() { foo(3, <|>); }"#,
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3<|>, ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3,<|> ); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
+        );
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(3, <|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (x: u32, <y: u32>)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["x: u32", "y: u32"]);
-        assert_eq!(info.active_parameter, Some(1));
     }
 
     #[test]
     fn test_fn_signature_two_args_empty() {
-        let info = call_info(
-            r#"fn foo(x: u32, y: u32) -> u32 {x + y}
-fn bar() { foo(<|>); }"#,
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo(x: u32, y: u32) -> u32
+                (<x: u32>, y: u32)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["x: u32", "y: u32"]);
-        assert_eq!(info.active_parameter, Some(0));
     }
 
     #[test]
     fn test_fn_signature_two_args_first_generics() {
-        let info = call_info(
-            r#"fn foo<T, U: Copy + Display>(x: T, y: U) -> u32 where T: Copy + Display, U: Debug {x + y}
-fn bar() { foo(<|>3, ); }"#,
-        );
-
-        assert_eq!(info.parameters(), ["x: T", "y: U"]);
-        assert_eq!(
-            info.label(),
+        check(
             r#"
 fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
-where T: Copy + Display,
-      U: Debug
-    "#
-            .trim()
+    where T: Copy + Display, U: Debug
+{ x + y }
+
+fn bar() { foo(<|>3, ); }
+"#,
+            expect![[r#"
+                fn foo<T, U: Copy + Display>(x: T, y: U) -> u32
+                where T: Copy + Display,
+                      U: Debug
+                (<x: T>, y: U)
+            "#]],
         );
-        assert_eq!(info.active_parameter, Some(0));
     }
 
     #[test]
     fn test_fn_signature_no_params() {
-        let info = call_info(
-            r#"fn foo<T>() -> T where T: Copy + Display {}
-fn bar() { foo(<|>); }"#,
-        );
-
-        assert!(info.parameters().is_empty());
-        assert_eq!(
-            info.label(),
+        check(
             r#"
-fn foo<T>() -> T
-where T: Copy + Display
-    "#
-            .trim()
+fn foo<T>() -> T where T: Copy + Display {}
+fn bar() { foo(<|>); }
+"#,
+            expect![[r#"
+                fn foo<T>() -> T
+                where T: Copy + Display
+                ()
+            "#]],
         );
-        assert!(info.active_parameter.is_none());
     }
 
     #[test]
     fn test_fn_signature_for_impl() {
-        let info = call_info(
-            r#"struct F; impl F { pub fn new() { F{}} }
-fn bar() {let _ : F = F::new(<|>);}"#,
+        check(
+            r#"
+struct F; impl F { pub fn new() { F{}} }
+fn bar() {let _ : F = F::new(<|>);}
+"#,
+            expect![[r#"
+                pub fn new()
+                ()
+            "#]],
         );
-
-        assert!(info.parameters().is_empty());
-        assert_eq!(info.active_parameter, None);
     }
 
     #[test]
     fn test_fn_signature_for_method_self() {
-        let info = call_info(
-            r#"struct F;
-impl F {
-    pub fn new() -> F{
-        F{}
-    }
-
-    pub fn do_it(&self) {}
-}
+        check(
+            r#"
+struct S;
+impl S { pub fn do_it(&self) {} }
 
 fn bar() {
-    let f : F = F::new();
-    f.do_it(<|>);
-}"#,
+    let s: S = S;
+    s.do_it(<|>);
+}
+"#,
+            expect![[r#"
+                pub fn do_it(&self)
+                (&self)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["&self"]);
-        assert_eq!(info.active_parameter, None);
     }
 
     #[test]
     fn test_fn_signature_for_method_with_arg() {
-        let info = call_info(
-            r#"struct F;
-impl F {
-    pub fn new() -> F{
-        F{}
-    }
-
-    pub fn do_it(&self, x: i32) {}
-}
+        check(
+            r#"
+struct S;
+impl S { pub fn do_it(&self, x: i32) {} }
 
 fn bar() {
-    let f : F = F::new();
-    f.do_it(<|>);
-}"#,
+    let s: S = S;
+    s.do_it(<|>);
+}
+"#,
+            expect![[r#"
+                pub fn do_it(&self, x: i32)
+                (&self, <x: i32>)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["&self", "x: i32"]);
-        assert_eq!(info.active_parameter, Some(1));
     }
 
     #[test]
     fn test_fn_signature_with_docs_simple() {
-        let info = call_info(
+        check(
             r#"
 /// test
 // non-doc-comment
@@ -387,17 +385,18 @@ fn bar() {
     let _ = foo(<|>);
 }
 "#,
+            expect![[r#"
+                test
+                ------
+                fn foo(j: u32) -> u32
+                (<j: u32>)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["j: u32"]);
-        assert_eq!(info.active_parameter, Some(0));
-        assert_eq!(info.label(), "fn foo(j: u32) -> u32");
-        assert_eq!(info.doc().map(|it| it.into()), Some("test".to_string()));
     }
 
     #[test]
     fn test_fn_signature_with_docs() {
-        let info = call_info(
+        check(
             r#"
 /// Adds one to the number given.
 ///
@@ -415,31 +414,26 @@ pub fn add_one(x: i32) -> i32 {
 pub fn do() {
     add_one(<|>
 }"#,
-        );
+            expect![[r##"
+                Adds one to the number given.
 
-        assert_eq!(info.parameters(), ["x: i32"]);
-        assert_eq!(info.active_parameter, Some(0));
-        assert_eq!(info.label(), "pub fn add_one(x: i32) -> i32");
-        assert_eq!(
-            info.doc().map(|it| it.into()),
-            Some(
-                r#"Adds one to the number given.
+                # Examples
 
-# Examples
+                ```
+                let five = 5;
 
-```
-let five = 5;
-
-assert_eq!(6, my_crate::add_one(5));
-```"#
-                    .to_string()
-            )
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                pub fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
         );
     }
 
     #[test]
     fn test_fn_signature_with_docs_impl() {
-        let info = call_info(
+        check(
             r#"
 struct addr;
 impl addr {
@@ -460,32 +454,28 @@ impl addr {
 pub fn do_it() {
     addr {};
     addr::add_one(<|>);
-}"#,
-        );
-
-        assert_eq!(info.parameters(), ["x: i32"]);
-        assert_eq!(info.active_parameter, Some(0));
-        assert_eq!(info.label(), "pub fn add_one(x: i32) -> i32");
-        assert_eq!(
-            info.doc().map(|it| it.into()),
-            Some(
-                r#"Adds one to the number given.
+}
+"#,
+            expect![[r##"
+                Adds one to the number given.
 
-# Examples
+                # Examples
 
-```
-let five = 5;
+                ```
+                let five = 5;
 
-assert_eq!(6, my_crate::add_one(5));
-```"#
-                    .to_string()
-            )
+                assert_eq!(6, my_crate::add_one(5));
+                ```
+                ------
+                pub fn add_one(x: i32) -> i32
+                (<x: i32>)
+            "##]],
         );
     }
 
     #[test]
     fn test_fn_signature_with_docs_from_actix() {
-        let info = call_info(
+        check(
             r#"
 struct WriteHandler<E>;
 
@@ -509,101 +499,102 @@ impl<E> WriteHandler<E> {
 pub fn foo(mut r: WriteHandler<()>) {
     r.finished(<|>);
 }
-
 "#,
-        );
-
-        assert_eq!(info.label(), "fn finished(&mut self, ctx: &mut Self::Context)".to_string());
-        assert_eq!(info.parameters(), ["&mut self", "ctx: &mut Self::Context"]);
-        assert_eq!(info.active_parameter, Some(1));
-        assert_eq!(
-            info.doc().map(|it| it.into()),
-            Some(
-                r#"Method is called when writer finishes.
-
-By default this method stops actor's `Context`."#
-                    .to_string()
-            )
+            expect![[r#"
+                Method is called when writer finishes.
+
+                By default this method stops actor's `Context`.
+                ------
+                fn finished(&mut self, ctx: &mut Self::Context)
+                (&mut self, <ctx: &mut Self::Context>)
+            "#]],
         );
     }
 
     #[test]
     fn call_info_bad_offset() {
         mark::check!(call_info_bad_offset);
-        let (analysis, position) = single_file_with_position(
-            r#"fn foo(x: u32, y: u32) -> u32 {x + y}
-               fn bar() { foo <|> (3, ); }"#,
+        check(
+            r#"
+fn foo(x: u32, y: u32) -> u32 {x + y}
+fn bar() { foo <|> (3, ); }
+"#,
+            expect![[""]],
         );
-        let call_info = analysis.call_info(position).unwrap();
-        assert!(call_info.is_none());
     }
 
     #[test]
-    fn test_nested_method_in_lamba() {
-        let info = call_info(
-            r#"struct Foo;
-
-impl Foo {
-    fn bar(&self, _: u32) { }
-}
+    fn test_nested_method_in_lambda() {
+        check(
+            r#"
+struct Foo;
+impl Foo { fn bar(&self, _: u32) { } }
 
 fn bar(_: u32) { }
 
 fn main() {
     let foo = Foo;
     std::thread::spawn(move || foo.bar(<|>));
-}"#,
+}
+"#,
+            expect![[r#"
+                fn bar(&self, _: u32)
+                (&self, <_: u32>)
+            "#]],
         );
-
-        assert_eq!(info.parameters(), ["&self", "_: u32"]);
-        assert_eq!(info.active_parameter, Some(1));
-        assert_eq!(info.label(), "fn bar(&self, _: u32)");
     }
 
     #[test]
     fn works_for_tuple_structs() {
-        let info = call_info(
+        check(
             r#"
 /// A cool tuple struct
 struct TS(u32, i32);
 fn main() {
     let s = TS(0, <|>);
-}"#,
+}
+"#,
+            expect![[r#"
+                A cool tuple struct
+                ------
+                struct TS(u32, i32) -> TS
+                (u32, <i32>)
+            "#]],
         );
-
-        assert_eq!(info.label(), "struct TS(u32, i32) -> TS");
-        assert_eq!(info.doc().map(|it| it.into()), Some("A cool tuple struct".to_string()));
-        assert_eq!(info.active_parameter, Some(1));
     }
 
     #[test]
     fn generic_struct() {
-        let info = call_info(
+        check(
             r#"
 struct TS<T>(T);
 fn main() {
     let s = TS(<|>);
-}"#,
+}
+"#,
+            expect![[r#"
+                struct TS<T>(T) -> TS
+                (<T>)
+            "#]],
         );
-
-        assert_eq!(info.label(), "struct TS<T>(T) -> TS");
-        assert_eq!(info.active_parameter, Some(0));
     }
 
     #[test]
     fn cant_call_named_structs() {
-        no_call_info(
+        check(
             r#"
 struct TS { x: u32, y: i32 }
 fn main() {
     let s = TS(<|>);
-}"#,
+}
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
     fn works_for_enum_variants() {
-        let info = call_info(
+        check(
             r#"
 enum E {
     /// A Variant
@@ -617,17 +608,19 @@ enum E {
 fn main() {
     let a = E::A(<|>);
 }
-            "#,
+"#,
+            expect![[r#"
+                A Variant
+                ------
+                E::A(0: i32)
+                (<0: i32>)
+            "#]],
         );
-
-        assert_eq!(info.label(), "E::A(0: i32)");
-        assert_eq!(info.doc().map(|it| it.into()), Some("A Variant".to_string()));
-        assert_eq!(info.active_parameter, Some(0));
     }
 
     #[test]
     fn cant_call_enum_records() {
-        no_call_info(
+        check(
             r#"
 enum E {
     /// A Variant
@@ -641,13 +634,14 @@ enum E {
 fn main() {
     let a = E::C(<|>);
 }
-            "#,
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
     fn fn_signature_for_macro() {
-        let info = call_info(
+        check(
             r#"
 /// empty macro
 macro_rules! foo {
@@ -657,31 +651,30 @@ macro_rules! foo {
 fn f() {
     foo!(<|>);
 }
-        "#,
+"#,
+            expect![[r#"
+                empty macro
+                ------
+                foo!()
+                ()
+            "#]],
         );
-
-        assert_eq!(info.label(), "foo!()");
-        assert_eq!(info.doc().map(|it| it.into()), Some("empty macro".to_string()));
     }
 
     #[test]
     fn fn_signature_for_call_in_macro() {
-        let info = call_info(
+        check(
             r#"
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            fn foo() {
-
-            }
-            id! {
-                fn bar() {
-                    foo(<|>);
-                }
-            }
-            "#,
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() { }
+id! {
+    fn bar() { foo(<|>); }
+}
+"#,
+            expect![[r#"
+                fn foo()
+                ()
+            "#]],
         );
-
-        assert_eq!(info.label(), "fn foo()");
     }
 }
diff --git a/crates/ra_ide/src/completion.rs b/crates/ra_ide/src/completion.rs
index d890b69d2..f3a5e9573 100644
--- a/crates/ra_ide/src/completion.rs
+++ b/crates/ra_ide/src/completion.rs
@@ -2,6 +2,9 @@ mod completion_config;
 mod completion_item;
 mod completion_context;
 mod presentation;
+mod patterns;
+#[cfg(test)]
+mod test_utils;
 
 mod complete_attribute;
 mod complete_dot;
@@ -15,8 +18,6 @@ mod complete_unqualified_path;
 mod complete_postfix;
 mod complete_macro_in_item_position;
 mod complete_trait_impl;
-#[cfg(test)]
-mod test_utils;
 
 use ra_ide_db::RootDatabase;
 
@@ -62,11 +63,11 @@ pub use crate::completion::{
 // There also snippet completions:
 //
 // .Expressions
-// - `pd` -> `println!("{:?}")`
-// - `ppd` -> `println!("{:#?}")`
+// - `pd` -> `eprintln!(" = {:?}", );")`
+// - `ppd` -> `eprintln!(" = {:#?}", );`
 //
 // .Items
-// - `tfn` -> `#[test] fn f(){}`
+// - `tfn` -> `#[test] fn feature(){}`
 // - `tmod` ->
 // ```rust
 // #[cfg(test)]
@@ -74,7 +75,7 @@ pub use crate::completion::{
 //     use super::*;
 //
 //     #[test]
-//     fn test_fn() {}
+//     fn test_name() {}
 // }
 // ```
 
@@ -125,3 +126,81 @@ pub(crate) fn completions(
 
     Some(acc)
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::completion_config::CompletionConfig;
+    use crate::mock_analysis::analysis_and_position;
+
+    struct DetailAndDocumentation<'a> {
+        detail: &'a str,
+        documentation: &'a str,
+    }
+
+    fn check_detail_and_documentation(ra_fixture: &str, expected: DetailAndDocumentation) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let config = CompletionConfig::default();
+        let completions = analysis.completions(&config, position).unwrap().unwrap();
+        for item in completions {
+            if item.detail() == Some(expected.detail) {
+                let opt = item.documentation();
+                let doc = opt.as_ref().map(|it| it.as_str());
+                assert_eq!(doc, Some(expected.documentation));
+                return;
+            }
+        }
+        panic!("completion detail not found: {}", expected.detail)
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_attr() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        #[doc = "Do the foo"]
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: "Do the foo" },
+        );
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_comment() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        /// Do the foo
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: " Do the foo" },
+        );
+    }
+}
diff --git a/crates/ra_ide/src/completion/complete_attribute.rs b/crates/ra_ide/src/completion/complete_attribute.rs
index fb3f0b743..d268c92be 100644
--- a/crates/ra_ide/src/completion/complete_attribute.rs
+++ b/crates/ra_ide/src/completion/complete_attribute.rs
@@ -20,6 +20,7 @@ pub(super) fn complete_attribute(acc: &mut Completions, ctx: &CompletionContext)
         {
             complete_derive(acc, ctx, token_tree)
         }
+        (_, Some(ast::AttrInput::TokenTree(_token_tree))) => {}
         _ => complete_attribute_start(acc, ctx, attribute),
     }
     Some(())
@@ -34,6 +35,10 @@ fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attr
         )
         .kind(CompletionItemKind::Attribute);
 
+        if let Some(lookup) = attr_completion.lookup {
+            item = item.lookup_by(lookup);
+        }
+
         match (attr_completion.snippet, ctx.config.snippet_cap) {
             (Some(snippet), Some(cap)) => {
                 item = item.insert_snippet(cap, snippet);
@@ -41,7 +46,7 @@ fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attr
             _ => {}
         }
 
-        if attribute.kind() == ast::AttrKind::Inner || !attr_completion.should_be_inner {
+        if attribute.kind() == ast::AttrKind::Inner || !attr_completion.prefer_inner {
             acc.add(item);
         }
     }
@@ -49,85 +54,74 @@ fn complete_attribute_start(acc: &mut Completions, ctx: &CompletionContext, attr
 
 struct AttrCompletion {
     label: &'static str,
+    lookup: Option<&'static str>,
+    snippet: Option<&'static str>,
+    prefer_inner: bool,
+}
+
+impl AttrCompletion {
+    const fn prefer_inner(self) -> AttrCompletion {
+        AttrCompletion { prefer_inner: true, ..self }
+    }
+}
+
+const fn attr(
+    label: &'static str,
+    lookup: Option<&'static str>,
     snippet: Option<&'static str>,
-    should_be_inner: bool,
+) -> AttrCompletion {
+    AttrCompletion { label, lookup, snippet, prefer_inner: false }
 }
 
 const ATTRIBUTES: &[AttrCompletion] = &[
-    AttrCompletion { label: "allow", snippet: Some("allow(${0:lint})"), should_be_inner: false },
-    AttrCompletion {
-        label: "cfg_attr",
-        snippet: Some("cfg_attr(${1:predicate}, ${0:attr})"),
-        should_be_inner: false,
-    },
-    AttrCompletion { label: "cfg", snippet: Some("cfg(${0:predicate})"), should_be_inner: false },
-    AttrCompletion { label: "deny", snippet: Some("deny(${0:lint})"), should_be_inner: false },
-    AttrCompletion {
-        label: "deprecated",
-        snippet: Some(r#"deprecated = "${0:reason}""#),
-        should_be_inner: false,
-    },
-    AttrCompletion {
-        label: "derive",
-        snippet: Some(r#"derive(${0:Debug})"#),
-        should_be_inner: false,
-    },
-    AttrCompletion { label: "doc", snippet: Some(r#"doc = "${0:docs}""#), should_be_inner: false },
-    AttrCompletion { label: "feature", snippet: Some("feature(${0:flag})"), should_be_inner: true },
-    AttrCompletion { label: "forbid", snippet: Some("forbid(${0:lint})"), should_be_inner: false },
+    attr("allow(…)", Some("allow"), Some("allow(${0:lint})")),
+    attr("cfg_attr(…)", Some("cfg_attr"), Some("cfg_attr(${1:predicate}, ${0:attr})")),
+    attr("cfg(…)", Some("cfg"), Some("cfg(${0:predicate})")),
+    attr("deny(…)", Some("deny"), Some("deny(${0:lint})")),
+    attr(r#"deprecated = "…""#, Some("deprecated"), Some(r#"deprecated = "${0:reason}""#)),
+    attr("derive(…)", Some("derive"), Some(r#"derive(${0:Debug})"#)),
+    attr(r#"doc = "…""#, Some("doc"), Some(r#"doc = "${0:docs}""#)),
+    attr("feature(…)", Some("feature"), Some("feature(${0:flag})")).prefer_inner(),
+    attr("forbid(…)", Some("forbid"), Some("forbid(${0:lint})")),
     // FIXME: resolve through macro resolution?
-    AttrCompletion { label: "global_allocator", snippet: None, should_be_inner: true },
-    AttrCompletion { label: "ignore", snippet: Some("ignore(${0:lint})"), should_be_inner: false },
-    AttrCompletion { label: "inline", snippet: Some("inline(${0:lint})"), should_be_inner: false },
-    AttrCompletion {
-        label: "link_name",
-        snippet: Some(r#"link_name = "${0:symbol_name}""#),
-        should_be_inner: false,
-    },
-    AttrCompletion { label: "link", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "macro_export", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "macro_use", snippet: None, should_be_inner: false },
-    AttrCompletion {
-        label: "must_use",
-        snippet: Some(r#"must_use = "${0:reason}""#),
-        should_be_inner: false,
-    },
-    AttrCompletion { label: "no_mangle", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "no_std", snippet: None, should_be_inner: true },
-    AttrCompletion { label: "non_exhaustive", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "panic_handler", snippet: None, should_be_inner: true },
-    AttrCompletion { label: "path", snippet: Some("path =\"${0:path}\""), should_be_inner: false },
-    AttrCompletion { label: "proc_macro", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "proc_macro_attribute", snippet: None, should_be_inner: false },
-    AttrCompletion {
-        label: "proc_macro_derive",
-        snippet: Some("proc_macro_derive(${0:Trait})"),
-        should_be_inner: false,
-    },
-    AttrCompletion {
-        label: "recursion_limit",
-        snippet: Some("recursion_limit = ${0:128}"),
-        should_be_inner: true,
-    },
-    AttrCompletion { label: "repr", snippet: Some("repr(${0:C})"), should_be_inner: false },
-    AttrCompletion {
-        label: "should_panic",
-        snippet: Some(r#"should_panic(expected = "${0:reason}")"#),
-        should_be_inner: false,
-    },
-    AttrCompletion {
-        label: "target_feature",
-        snippet: Some("target_feature = \"${0:feature}\""),
-        should_be_inner: false,
-    },
-    AttrCompletion { label: "test", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "used", snippet: None, should_be_inner: false },
-    AttrCompletion { label: "warn", snippet: Some("warn(${0:lint})"), should_be_inner: false },
-    AttrCompletion {
-        label: "windows_subsystem",
-        snippet: Some(r#"windows_subsystem = "${0:subsystem}""#),
-        should_be_inner: true,
-    },
+    attr("global_allocator", None, None).prefer_inner(),
+    attr(r#"ignore = "…""#, Some("ignore"), Some(r#"ignore = "${0:reason}""#)),
+    attr("inline(…)", Some("inline"), Some("inline(${0:lint})")),
+    attr(r#"link_name = "…""#, Some("link_name"), Some(r#"link_name = "${0:symbol_name}""#)),
+    attr("link", None, None),
+    attr("macro_export", None, None),
+    attr("macro_use", None, None),
+    attr(r#"must_use = "…""#, Some("must_use"), Some(r#"must_use = "${0:reason}""#)),
+    attr("no_mangle", None, None),
+    attr("no_std", None, None).prefer_inner(),
+    attr("non_exhaustive", None, None),
+    attr("panic_handler", None, None).prefer_inner(),
+    attr("path = \"…\"", Some("path"), Some("path =\"${0:path}\"")),
+    attr("proc_macro", None, None),
+    attr("proc_macro_attribute", None, None),
+    attr("proc_macro_derive(…)", Some("proc_macro_derive"), Some("proc_macro_derive(${0:Trait})")),
+    attr("recursion_limit = …", Some("recursion_limit"), Some("recursion_limit = ${0:128}"))
+        .prefer_inner(),
+    attr("repr(…)", Some("repr"), Some("repr(${0:C})")),
+    attr(
+        "should_panic(…)",
+        Some("should_panic"),
+        Some(r#"should_panic(expected = "${0:reason}")"#),
+    ),
+    attr(
+        r#"target_feature = "…""#,
+        Some("target_feature"),
+        Some("target_feature = \"${0:feature}\""),
+    ),
+    attr("test", None, None),
+    attr("used", None, None),
+    attr("warn(…)", Some("warn"), Some("warn(${0:lint})")),
+    attr(
+        r#"windows_subsystem = "…""#,
+        Some("windows_subsystem"),
+        Some(r#"windows_subsystem = "${0:subsystem}""#),
+    )
+    .prefer_inner(),
 ];
 
 fn complete_derive(acc: &mut Completions, ctx: &CompletionContext, derive_input: ast::TokenTree) {
@@ -201,7 +195,7 @@ fn parse_derive_input(derive_input: ast::TokenTree) -> Result<FxHashSet<String>,
 
 fn get_derive_names_in_scope(ctx: &CompletionContext) -> FxHashSet<String> {
     let mut result = FxHashSet::default();
-    ctx.scope().process_all_names(&mut |name, scope_def| {
+    ctx.scope.process_all_names(&mut |name, scope_def| {
         if let hir::ScopeDef::MacroDef(mac) = scope_def {
             if mac.is_derive_macro() {
                 result.insert(name.to_string());
@@ -232,624 +226,147 @@ const DEFAULT_DERIVE_COMPLETIONS: &[DeriveCompletion] = &[
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
 
-    fn do_attr_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Attribute)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Attribute);
+        expect.assert_eq(&actual);
     }
 
     #[test]
     fn empty_derive_completion() {
-        assert_debug_snapshot!(
-            do_attr_completion(
-                    r"
-                    #[derive(<|>)]
-                    struct Test {}
-                    ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Clone",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Clone",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Copy, Clone",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Copy, Clone",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Debug",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Debug",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Default",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Default",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Eq, PartialEq",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Eq, PartialEq",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Hash",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Hash",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Ord, PartialOrd, Eq, PartialEq",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Ord, PartialOrd, Eq, PartialEq",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "PartialEq",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "PartialEq",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "PartialOrd, PartialEq",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "PartialOrd, PartialEq",
-                kind: Attribute,
-            },
-        ]
-            "###
+        check(
+            r#"
+#[derive(<|>)]
+struct Test {}
+        "#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq, PartialEq
+                at Hash
+                at Ord, PartialOrd, Eq, PartialEq
+                at PartialEq
+                at PartialOrd, PartialEq
+            "#]],
         );
     }
 
     #[test]
     fn no_completion_for_incorrect_derive() {
-        assert_debug_snapshot!(
-            do_attr_completion(
-                r"
-                    #[derive{<|>)]
-                    struct Test {}
-                    ",
-            ),
-            @"[]"
-        );
+        check(
+            r#"
+#[derive{<|>)]
+struct Test {}
+"#,
+            expect![[r#""#]],
+        )
     }
 
     #[test]
     fn derive_with_input_completion() {
-        assert_debug_snapshot!(
-            do_attr_completion(
-                    r"
-                    #[derive(serde::Serialize, PartialEq, <|>)]
-                    struct Test {}
-                    ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Clone",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Clone",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Copy, Clone",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Copy, Clone",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Debug",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Debug",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Default",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Default",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Eq",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Eq",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Hash",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Hash",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "Ord, PartialOrd, Eq",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "Ord, PartialOrd, Eq",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "PartialOrd",
-                source_range: 59..59,
-                delete: 59..59,
-                insert: "PartialOrd",
-                kind: Attribute,
-            },
-        ]
-            "###
-        );
+        check(
+            r#"
+#[derive(serde::Serialize, PartialEq, <|>)]
+struct Test {}
+"#,
+            expect![[r#"
+                at Clone
+                at Copy, Clone
+                at Debug
+                at Default
+                at Eq
+                at Hash
+                at Ord, PartialOrd, Eq
+                at PartialOrd
+            "#]],
+        )
     }
 
     #[test]
     fn test_attribute_completion() {
-        assert_debug_snapshot!(
-        do_attr_completion(
-                r"
-                #[<|>]
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "allow",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "allow(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "cfg",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "cfg(${0:predicate})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "cfg_attr",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "cfg_attr(${1:predicate}, ${0:attr})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "deny",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "deny(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "deprecated",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "deprecated = \"${0:reason}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "derive",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "derive(${0:Debug})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "doc",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "doc = \"${0:docs}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "forbid",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "forbid(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "ignore",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "ignore(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "inline",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "inline(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "link",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "link",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "link_name",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "link_name = \"${0:symbol_name}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "macro_export",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "macro_export",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "macro_use",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "macro_use",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "must_use",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "must_use = \"${0:reason}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "no_mangle",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "no_mangle",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "non_exhaustive",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "non_exhaustive",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "path",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "path =\"${0:path}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "proc_macro",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro_attribute",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "proc_macro_attribute",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro_derive",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "proc_macro_derive(${0:Trait})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "repr",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "repr(${0:C})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "should_panic",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "should_panic(expected = \"${0:reason}\")",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "target_feature",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "target_feature = \"${0:feature}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "test",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "test",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "used",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "used",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "warn",
-                source_range: 19..19,
-                delete: 19..19,
-                insert: "warn(${0:lint})",
-                kind: Attribute,
-            },
-        ]
-        "###
-        );
+        check(
+            r#"#[<|>]"#,
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at forbid(…)
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at non_exhaustive
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+            "#]],
+        )
+    }
+
+    #[test]
+    fn test_attribute_completion_inside_nested_attr() {
+        check(r#"#[allow(<|>)]"#, expect![[]])
     }
 
     #[test]
     fn test_inner_attribute_completion() {
-        assert_debug_snapshot!(
-        do_attr_completion(
-                r"
-                #![<|>]
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "allow",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "allow(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "cfg",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "cfg(${0:predicate})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "cfg_attr",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "cfg_attr(${1:predicate}, ${0:attr})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "deny",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "deny(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "deprecated",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "deprecated = \"${0:reason}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "derive",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "derive(${0:Debug})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "doc",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "doc = \"${0:docs}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "feature",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "feature(${0:flag})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "forbid",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "forbid(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "global_allocator",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "global_allocator",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "ignore",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "ignore(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "inline",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "inline(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "link",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "link",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "link_name",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "link_name = \"${0:symbol_name}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "macro_export",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "macro_export",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "macro_use",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "macro_use",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "must_use",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "must_use = \"${0:reason}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "no_mangle",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "no_mangle",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "no_std",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "no_std",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "non_exhaustive",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "non_exhaustive",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "panic_handler",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "panic_handler",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "path",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "path =\"${0:path}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "proc_macro",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro_attribute",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "proc_macro_attribute",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "proc_macro_derive",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "proc_macro_derive(${0:Trait})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "recursion_limit",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "recursion_limit = ${0:128}",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "repr",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "repr(${0:C})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "should_panic",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "should_panic(expected = \"${0:reason}\")",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "target_feature",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "target_feature = \"${0:feature}\"",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "test",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "test",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "used",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "used",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "warn",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "warn(${0:lint})",
-                kind: Attribute,
-            },
-            CompletionItem {
-                label: "windows_subsystem",
-                source_range: 20..20,
-                delete: 20..20,
-                insert: "windows_subsystem = \"${0:subsystem}\"",
-                kind: Attribute,
-            },
-        ]
-        "###
+        check(
+            r"#![<|>]",
+            expect![[r#"
+                at allow(…)
+                at cfg(…)
+                at cfg_attr(…)
+                at deny(…)
+                at deprecated = "…"
+                at derive(…)
+                at doc = "…"
+                at feature(…)
+                at forbid(…)
+                at global_allocator
+                at ignore = "…"
+                at inline(…)
+                at link
+                at link_name = "…"
+                at macro_export
+                at macro_use
+                at must_use = "…"
+                at no_mangle
+                at no_std
+                at non_exhaustive
+                at panic_handler
+                at path = "…"
+                at proc_macro
+                at proc_macro_attribute
+                at proc_macro_derive(…)
+                at recursion_limit = …
+                at repr(…)
+                at should_panic(…)
+                at target_feature = "…"
+                at test
+                at used
+                at warn(…)
+                at windows_subsystem = "…"
+            "#]],
         );
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_dot.rs b/crates/ra_ide/src/completion/complete_dot.rs
index 05f825c6f..532665285 100644
--- a/crates/ra_ide/src/completion/complete_dot.rs
+++ b/crates/ra_ide/src/completion/complete_dot.rs
@@ -1,17 +1,12 @@
-//! FIXME: write short doc here
+//! Completes references after dot (fields and method calls).
 
 use hir::{HasVisibility, Type};
-
-use crate::{
-    completion::{
-        completion_context::CompletionContext,
-        completion_item::{CompletionKind, Completions},
-    },
-    CompletionItem,
-};
 use rustc_hash::FxHashSet;
+use test_utils::mark;
 
-/// Complete dot accesses, i.e. fields or methods (and .await syntax).
+use crate::completion::{completion_context::CompletionContext, completion_item::Completions};
+
+/// Complete dot accesses, i.e. fields or methods.
 pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     let dot_receiver = match &ctx.dot_receiver {
         Some(expr) => expr,
@@ -23,24 +18,18 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
         _ => return,
     };
 
-    if !ctx.is_call {
+    if ctx.is_call {
+        mark::hit!(test_no_struct_field_completion_for_method_call);
+    } else {
         complete_fields(acc, ctx, &receiver_ty);
     }
     complete_methods(acc, ctx, &receiver_ty);
-
-    // Suggest .await syntax for types that implement Future trait
-    if receiver_ty.impls_future(ctx.db) {
-        CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
-            .detail("expr.await")
-            .insert_text("await")
-            .add_to(acc);
-    }
 }
 
 fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     for receiver in receiver.autoderef(ctx.db) {
         for (field, ty) in receiver.fields(ctx.db) {
-            if ctx.scope().module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
+            if ctx.scope.module().map_or(false, |m| !field.is_visible_from(ctx.db, m)) {
                 // Skip private field. FIXME: If the definition location of the
                 // field is editable, we should show the completion
                 continue;
@@ -57,10 +46,10 @@ fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: &Ty
 fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &Type) {
     if let Some(krate) = ctx.krate {
         let mut seen_methods = FxHashSet::default();
-        let traits_in_scope = ctx.scope().traits_in_scope();
+        let traits_in_scope = ctx.scope.traits_in_scope();
         receiver.iterate_method_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, func| {
             if func.has_self_param(ctx.db)
-                && ctx.scope().module().map_or(true, |m| func.is_visible_from(ctx.db, m))
+                && ctx.scope.module().map_or(true, |m| func.is_visible_from(ctx.db, m))
                 && seen_methods.insert(func.name(ctx.db))
             {
                 acc.add_function(ctx, func, None);
@@ -72,801 +61,356 @@ fn complete_methods(acc: &mut Completions, ctx: &CompletionContext, receiver: &T
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
+    use test_utils::mark;
+
+    use crate::completion::{test_utils::completion_list, CompletionKind};
 
-    fn do_ref_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Reference)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
     }
 
     #[test]
-    fn test_struct_field_completion() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-                r"
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                a.<|>
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 94..94,
-                delete: 94..94,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+    fn test_struct_field_and_method_completion() {
+        check(
+            r#"
+struct S { foo: u32 }
+impl S {
+    fn bar(&self) {}
+}
+fn foo(s: S) { s.<|> }
+"#,
+            expect![[r#"
+                me bar() fn bar(&self)
+                fd foo   u32
+            "#]],
         );
     }
 
     #[test]
     fn test_struct_field_completion_self() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A {
-                /// This is the_field
-                the_field: (u32,)
-            }
-            impl A {
-                fn foo(self) {
-                    self.<|>
-                }
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "foo()",
-                source_range: 187..187,
-                delete: 187..187,
-                insert: "foo()$0",
-                kind: Method,
-                lookup: "foo",
-                detail: "fn foo(self)",
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 187..187,
-                delete: 187..187,
-                insert: "the_field",
-                kind: Field,
-                detail: "(u32,)",
-                documentation: Documentation(
-                    "This is the_field",
-                ),
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+struct S { the_field: (u32,) }
+impl S {
+    fn foo(self) { self.<|> }
+}
+"#,
+            expect![[r#"
+                me foo()     fn foo(self)
+                fd the_field (u32,)
+            "#]],
+        )
     }
 
     #[test]
     fn test_struct_field_completion_autoderef() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A { the_field: (u32, i32) }
-            impl A {
-                fn foo(&self) {
-                    self.<|>
-                }
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "foo()",
-                source_range: 126..126,
-                delete: 126..126,
-                insert: "foo()$0",
-                kind: Method,
-                lookup: "foo",
-                detail: "fn foo(&self)",
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 126..126,
-                delete: 126..126,
-                insert: "the_field",
-                kind: Field,
-                detail: "(u32, i32)",
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+struct A { the_field: (u32, i32) }
+impl A {
+    fn foo(&self) { self.<|> }
+}
+"#,
+            expect![[r#"
+                me foo()     fn foo(&self)
+                fd the_field (u32, i32)
+            "#]],
+        )
     }
 
     #[test]
     fn test_no_struct_field_completion_for_method_call() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A { the_field: u32 }
-            fn foo(a: A) {
-               a.<|>()
-            }
-            ",
-        ),
-        @"[]"
+        mark::check!(test_no_struct_field_completion_for_method_call);
+        check(
+            r#"
+struct A { the_field: u32 }
+fn foo(a: A) { a.<|>() }
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
-    fn test_struct_field_visibility_private() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            mod inner {
-                struct A {
-                    private_field: u32,
-                    pub pub_field: u32,
-                    pub(crate) crate_field: u32,
-                    pub(super) super_field: u32,
-                }
-            }
-            fn foo(a: inner::A) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "crate_field",
-                source_range: 313..313,
-                delete: 313..313,
-                insert: "crate_field",
-                kind: Field,
-                detail: "u32",
-            },
-            CompletionItem {
-                label: "pub_field",
-                source_range: 313..313,
-                delete: 313..313,
-                insert: "pub_field",
-                kind: Field,
-                detail: "u32",
-            },
-            CompletionItem {
-                label: "super_field",
-                source_range: 313..313,
-                delete: 313..313,
-                insert: "super_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
-        );
+    fn test_visibility_filtering() {
+        check(
+            r#"
+mod inner {
+    pub struct A {
+        private_field: u32,
+        pub pub_field: u32,
+        pub(crate) crate_field: u32,
+        pub(super) super_field: u32,
     }
-
-    #[test]
-    fn test_union_field_completion() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            union Un {
-                field: u8,
-                other: u16,
-            }
-
-            fn foo(u: Un) {
-                u.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "field",
-                source_range: 140..140,
-                delete: 140..140,
-                insert: "field",
-                kind: Field,
-                detail: "u8",
-            },
-            CompletionItem {
-                label: "other",
-                source_range: 140..140,
-                delete: 140..140,
-                insert: "other",
-                kind: Field,
-                detail: "u16",
-            },
-        ]
-        "###
+}
+fn foo(a: inner::A) { a.<|> }
+"#,
+            expect![[r#"
+                fd crate_field u32
+                fd pub_field   u32
+                fd super_field u32
+            "#]],
         );
-    }
 
-    #[test]
-    fn test_method_completion() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A {}
-            impl A {
-                fn the_method(&self) {}
-            }
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 144..144,
-                delete: 144..144,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct A {}
+mod m {
+    impl super::A {
+        fn private_method(&self) {}
+        pub(super) fn the_method(&self) {}
+    }
+}
+fn foo(a: A) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() pub(super) fn the_method(&self)
+            "#]],
         );
     }
 
     #[test]
-    fn test_method_completion_only_fitting_impls() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct A<T> {}
-            impl A<u32> {
-                fn the_method(&self) {}
-            }
-            impl A<i32> {
-                fn the_other_method(&self) {}
-            }
-            fn foo(a: A<u32>) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 243..243,
-                delete: 243..243,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
+    fn test_union_field_completion() {
+        check(
+            r#"
+union U { field: u8, other: u16 }
+fn foo(u: U) { u.<|> }
+"#,
+            expect![[r#"
+                fd field u8
+                fd other u16
+            "#]],
         );
     }
 
     #[test]
-    fn test_method_completion_private() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct A {}
-            mod m {
-                impl super::A {
-                    fn private_method(&self) {}
-                    pub(super) fn the_method(&self) {}
-                }
-            }
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 256..256,
-                delete: 256..256,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "pub(super) fn the_method(&self)",
-            },
-        ]
-        "###
-        );
+    fn test_method_completion_only_fitting_impls() {
+        check(
+            r#"
+struct A<T> {}
+impl A<u32> {
+    fn the_method(&self) {}
+}
+impl A<i32> {
+    fn the_other_method(&self) {}
+}
+fn foo(a: A<u32>) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
+        )
     }
 
     #[test]
     fn test_trait_method_completion() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct A {}
-            trait Trait { fn the_method(&self); }
-            impl Trait for A {}
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 151..151,
-                delete: 151..151,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct A {}
+trait Trait { fn the_method(&self); }
+impl Trait for A {}
+fn foo(a: A) { a.<|> }
+"#,
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
         );
     }
 
     #[test]
     fn test_trait_method_completion_deduplicated() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct A {}
-            trait Trait { fn the_method(&self); }
-            impl<T> Trait for T {}
-            fn foo(a: &A) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 155..155,
-                delete: 155..155,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
+        check(
+            r"
+struct A {}
+trait Trait { fn the_method(&self); }
+impl<T> Trait for T {}
+fn foo(a: &A) { a.<|> }
+",
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
         );
     }
 
     #[test]
     fn completes_trait_method_from_other_module() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct A {}
-            mod m {
-                pub trait Trait { fn the_method(&self); }
-            }
-            use m::Trait;
-            impl Trait for A {}
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn test_no_non_self_method() {
-        assert_debug_snapshot!(
-        do_ref_completion(
+        check(
             r"
-            struct A {}
-            impl A {
-                fn the_method() {}
-            }
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-        ),
-        @"[]"
+struct A {}
+mod m {
+    pub trait Trait { fn the_method(&self); }
+}
+use m::Trait;
+impl Trait for A {}
+fn foo(a: A) { a.<|> }
+",
+            expect![[r#"
+                me the_method() fn the_method(&self)
+            "#]],
         );
     }
 
     #[test]
-    fn test_method_attr_filtering() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A {}
-            impl A {
-                #[inline]
-                fn the_method(&self) {
-                    let x = 1;
-                    let y = 2;
-                }
-            }
-            fn foo(a: A) {
-               a.<|>
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 249..249,
-                delete: 249..249,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "fn the_method(&self)",
-            },
-        ]
-        "###
+    fn test_no_non_self_method() {
+        check(
+            r#"
+struct A {}
+impl A {
+    fn the_method() {}
+}
+fn foo(a: A) {
+   a.<|>
+}
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
     fn test_tuple_field_completion() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            fn foo() {
-               let b = (0, 3.14);
-               b.<|>
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "0",
-                source_range: 75..75,
-                delete: 75..75,
-                insert: "0",
-                kind: Field,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "1",
-                source_range: 75..75,
-                delete: 75..75,
-                insert: "1",
-                kind: Field,
-                detail: "f64",
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+fn foo() {
+   let b = (0, 3.14);
+   b.<|>
+}
+"#,
+            expect![[r#"
+                fd 0 i32
+                fd 1 f64
+            "#]],
+        )
     }
 
     #[test]
     fn test_tuple_field_inference() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            pub struct S;
-            impl S {
-                pub fn blah(&self) {}
-            }
+        check(
+            r#"
+pub struct S;
+impl S { pub fn blah(&self) {} }
 
-            struct T(S);
+struct T(S);
 
-            impl T {
-                fn foo(&self) {
-                    // FIXME: This doesn't work without the trailing `a` as `0.` is a float
-                    self.0.a<|>
-                }
-            }
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "blah()",
-                source_range: 299..300,
-                delete: 299..300,
-                insert: "blah()$0",
-                kind: Method,
-                lookup: "blah",
-                detail: "pub fn blah(&self)",
-            },
-        ]
-        "###
-        );
+impl T {
+    fn foo(&self) {
+        // FIXME: This doesn't work without the trailing `a` as `0.` is a float
+        self.0.a<|>
     }
-
-    #[test]
-    fn test_completion_works_in_consts() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-            r"
-            struct A { the_field: u32 }
-            const X: u32 = {
-                A { the_field: 92 }.<|>
-            };
-            ",
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 106..106,
-                delete: 106..106,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+}
+"#,
+            expect![[r#"
+                me blah() pub fn blah(&self)
+            "#]],
         );
     }
 
     #[test]
-    fn test_completion_await_impls_future() {
-        assert_debug_snapshot!(
-        do_completion(
-            r###"
-            //- /main.rs
-            use std::future::*;
-            struct A {}
-            impl Future for A {}
-            fn foo(a: A) {
-                a.<|>
-            }
-
-            //- /std/lib.rs
-            pub mod future {
-                #[lang = "future_trait"]
-                pub trait Future {}
-            }
-            "###, CompletionKind::Keyword),
-        @r###"
-        [
-            CompletionItem {
-                label: "await",
-                source_range: 74..74,
-                delete: 74..74,
-                insert: "await",
-                detail: "expr.await",
-            },
-        ]
-        "###
-        )
-    }
-
-    #[test]
-    fn test_super_super_completion() {
-        assert_debug_snapshot!(
-        do_ref_completion(
-                r"
-                mod a {
-                    const A: usize = 0;
-
-                    mod b {
-                        const B: usize = 0;
-
-                        mod c {
-                            use super::super::<|>
-                        }
-                    }
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "A",
-                source_range: 217..217,
-                delete: 217..217,
-                insert: "A",
-                kind: Const,
-            },
-            CompletionItem {
-                label: "b",
-                source_range: 217..217,
-                delete: 217..217,
-                insert: "b",
-                kind: Module,
-            },
-        ]
-        "###
+    fn test_completion_works_in_consts() {
+        check(
+            r#"
+struct A { the_field: u32 }
+const X: u32 = {
+    A { the_field: 92 }.<|>
+};
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
         );
     }
 
     #[test]
     fn works_in_simple_macro_1() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                    m!(a.x<|>)
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 156..157,
-                delete: 156..157,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn works_in_simple_macro_recursive() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                    m!(a.x<|>)
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 156..157,
-                delete: 156..157,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(a.x<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
         );
     }
 
     #[test]
     fn works_in_simple_macro_2() {
         // this doesn't work yet because the macro doesn't expand without the token -- maybe it can be fixed with better recovery
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                    m!(a.<|>)
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 156..156,
-                delete: 156..156,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(a.<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
         );
     }
 
     #[test]
     fn works_in_simple_macro_recursive_1() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                    m!(m!(m!(a.x<|>)))
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 162..163,
-                delete: 162..163,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo(a: A) {
+    m!(m!(m!(a.x<|>)))
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
         );
     }
 
     #[test]
     fn macro_expansion_resilient() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-                macro_rules! dbg {
-                    () => {};
-                    ($val:expr) => {
-                        match $val { tmp => { tmp } }
-                    };
-                    // Trailing comma with single argument is ignored
-                    ($val:expr,) => { $crate::dbg!($val) };
-                    ($($val:expr),+ $(,)?) => {
-                        ($($crate::dbg!($val)),+,)
-                    };
-                }
-                struct A { the_field: u32 }
-                fn foo(a: A) {
-                    dbg!(a.<|>)
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 552..552,
-                delete: 552..552,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! dbg {
+    () => {};
+    ($val:expr) => {
+        match $val { tmp => { tmp } }
+    };
+    // Trailing comma with single argument is ignored
+    ($val:expr,) => { $crate::dbg!($val) };
+    ($($val:expr),+ $(,)?) => {
+        ($($crate::dbg!($val)),+,)
+    };
+}
+struct A { the_field: u32 }
+fn foo(a: A) {
+    dbg!(a.<|>)
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
         );
     }
 
     #[test]
-    fn test_method_completion_3547() {
-        assert_debug_snapshot!(
-            do_ref_completion(
-                r"
-            struct HashSet<T> {}
-            impl<T> HashSet<T> {
-                pub fn the_method(&self) {}
-            }
-            fn foo() {
-                let s: HashSet<_>;
-                s.<|>
-            }
-            ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "the_method()",
-                source_range: 201..201,
-                delete: 201..201,
-                insert: "the_method()$0",
-                kind: Method,
-                lookup: "the_method",
-                detail: "pub fn the_method(&self)",
-            },
-        ]
-        "###
+    fn test_method_completion_issue_3547() {
+        check(
+            r#"
+struct HashSet<T> {}
+impl<T> HashSet<T> {
+    pub fn the_method(&self) {}
+}
+fn foo() {
+    let s: HashSet<_>;
+    s.<|>
+}
+"#,
+            expect![[r#"
+                me the_method() pub fn the_method(&self)
+            "#]],
         );
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_fn_param.rs b/crates/ra_ide/src/completion/complete_fn_param.rs
index a661932a3..db2abb4f1 100644
--- a/crates/ra_ide/src/completion/complete_fn_param.rs
+++ b/crates/ra_ide/src/completion/complete_fn_param.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! See `complete_fn_param`.
 
 use ra_syntax::{
     ast::{self, ModuleItemOwner},
@@ -18,6 +18,7 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
     }
 
     let mut params = FxHashMap::default();
+    let me = ctx.token.ancestors().find_map(ast::FnDef::cast);
     for node in ctx.token.parent().ancestors() {
         let items = match_ast! {
             match node {
@@ -28,25 +29,26 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
         };
         for item in items {
             if let ast::ModuleItem::FnDef(func) = item {
+                if Some(&func) == me.as_ref() {
+                    continue;
+                }
                 func.param_list().into_iter().flat_map(|it| it.params()).for_each(|param| {
                     let text = param.syntax().text().to_string();
-                    params.entry(text).or_insert((0, param)).0 += 1;
+                    params.entry(text).or_insert(param);
                 })
             }
         }
     }
+
     params
         .into_iter()
-        .filter_map(|(label, (count, param))| {
+        .filter_map(|(label, param)| {
             let lookup = param.pat()?.syntax().text().to_string();
-            if count < 2 {
-                None
-            } else {
-                Some((label, lookup))
-            }
+            Some((label, lookup))
         })
         .for_each(|(label, lookup)| {
             CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
+                .kind(crate::CompletionItemKind::Binding)
                 .lookup_by(lookup)
                 .add_to(acc)
         });
@@ -54,85 +56,70 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    fn do_magic_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Magic)
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Magic);
+        expect.assert_eq(&actual);
     }
 
     #[test]
     fn test_param_completion_last_param() {
-        assert_debug_snapshot!(
-        do_magic_completion(
-                r"
-                fn foo(file_id: FileId) {}
-                fn bar(file_id: FileId) {}
-                fn baz(file<|>) {}
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "file_id: FileId",
-                source_range: 110..114,
-                delete: 110..114,
-                insert: "file_id: FileId",
-                lookup: "file_id",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn foo(file_id: FileId) {}
+fn bar(file_id: FileId) {}
+fn baz(file<|>) {}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
         );
     }
 
     #[test]
     fn test_param_completion_nth_param() {
-        assert_debug_snapshot!(
-        do_magic_completion(
-                r"
-                fn foo(file_id: FileId) {}
-                fn bar(file_id: FileId) {}
-                fn baz(file<|>, x: i32) {}
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "file_id: FileId",
-                source_range: 110..114,
-                delete: 110..114,
-                insert: "file_id: FileId",
-                lookup: "file_id",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn foo(file_id: FileId) {}
+fn baz(file<|>, x: i32) {}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
         );
     }
 
     #[test]
     fn test_param_completion_trait_param() {
-        assert_debug_snapshot!(
-        do_magic_completion(
-                r"
-                pub(crate) trait SourceRoot {
-                    pub fn contains(&self, file_id: FileId) -> bool;
-                    pub fn module_map(&self) -> &ModuleMap;
-                    pub fn lines(&self, file_id: FileId) -> &LineIndex;
-                    pub fn syntax(&self, file<|>)
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "file_id: FileId",
-                source_range: 289..293,
-                delete: 289..293,
-                insert: "file_id: FileId",
-                lookup: "file_id",
-            },
-        ]
-        "###
+        check(
+            r#"
+pub(crate) trait SourceRoot {
+    pub fn contains(&self, file_id: FileId) -> bool;
+    pub fn module_map(&self) -> &ModuleMap;
+    pub fn lines(&self, file_id: FileId) -> &LineIndex;
+    pub fn syntax(&self, file<|>)
+}
+"#,
+            expect![[r#"
+                bn file_id: FileId
+            "#]],
         );
     }
+
+    #[test]
+    fn completes_param_in_inner_function() {
+        check(
+            r#"
+fn outer(text: String) {
+    fn inner(<|>)
+}
+"#,
+            expect![[r#"
+                bn text: String
+            "#]],
+        )
+    }
 }
diff --git a/crates/ra_ide/src/completion/complete_keyword.rs b/crates/ra_ide/src/completion/complete_keyword.rs
index fd95bc410..fcdaeef49 100644
--- a/crates/ra_ide/src/completion/complete_keyword.rs
+++ b/crates/ra_ide/src/completion/complete_keyword.rs
@@ -1,11 +1,7 @@
 //! FIXME: write short doc here
 
-use ra_syntax::{
-    ast::{self, LoopBodyOwner},
-    match_ast, AstNode,
-    SyntaxKind::*,
-    SyntaxToken,
-};
+use ra_syntax::{ast, SyntaxKind};
+use test_utils::mark;
 
 use crate::completion::{
     CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
@@ -16,14 +12,14 @@ pub(super) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
     let source_range = ctx.source_range();
     match (ctx.use_item_syntax.as_ref(), ctx.path_prefix.as_ref()) {
         (Some(_), None) => {
-            CompletionItem::new(CompletionKind::Keyword, source_range, "crate")
+            CompletionItem::new(CompletionKind::Keyword, source_range, "crate::")
                 .kind(CompletionItemKind::Keyword)
                 .insert_text("crate::")
                 .add_to(acc);
             CompletionItem::new(CompletionKind::Keyword, source_range, "self")
                 .kind(CompletionItemKind::Keyword)
                 .add_to(acc);
-            CompletionItem::new(CompletionKind::Keyword, source_range, "super")
+            CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
                 .kind(CompletionItemKind::Keyword)
                 .insert_text("super::")
                 .add_to(acc);
@@ -32,77 +28,147 @@ pub(super) fn complete_use_tree_keyword(acc: &mut Completions, ctx: &CompletionC
             CompletionItem::new(CompletionKind::Keyword, source_range, "self")
                 .kind(CompletionItemKind::Keyword)
                 .add_to(acc);
-            CompletionItem::new(CompletionKind::Keyword, source_range, "super")
+            CompletionItem::new(CompletionKind::Keyword, source_range, "super::")
                 .kind(CompletionItemKind::Keyword)
                 .insert_text("super::")
                 .add_to(acc);
         }
         _ => {}
     }
-}
 
-fn keyword(ctx: &CompletionContext, kw: &str, snippet: &str) -> CompletionItem {
-    let res = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw)
-        .kind(CompletionItemKind::Keyword);
-
-    match ctx.config.snippet_cap {
-        Some(cap) => res.insert_snippet(cap, snippet),
-        _ => res.insert_text(if snippet.contains('$') { kw } else { snippet }),
+    // Suggest .await syntax for types that implement Future trait
+    if let Some(receiver) = &ctx.dot_receiver {
+        if let Some(ty) = ctx.sema.type_of_expr(receiver) {
+            if ty.impls_future(ctx.db) {
+                CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
+                    .kind(CompletionItemKind::Keyword)
+                    .detail("expr.await")
+                    .insert_text("await")
+                    .add_to(acc);
+            }
+        };
     }
-    .build()
 }
 
 pub(super) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionContext) {
-    if !ctx.is_trivial_path {
+    if ctx.token.kind() == SyntaxKind::COMMENT {
+        mark::hit!(no_keyword_completion_in_comments);
         return;
     }
 
-    let fn_def = match &ctx.function_syntax {
-        Some(it) => it,
-        None => return,
-    };
-    acc.add(keyword(ctx, "if", "if $0 {}"));
-    acc.add(keyword(ctx, "match", "match $0 {}"));
-    acc.add(keyword(ctx, "while", "while $0 {}"));
-    acc.add(keyword(ctx, "loop", "loop {$0}"));
+    let has_trait_or_impl_parent = ctx.has_impl_parent || ctx.has_trait_parent;
+    if ctx.trait_as_prev_sibling || ctx.impl_as_prev_sibling {
+        add_keyword(ctx, acc, "where", "where ");
+        return;
+    }
+    if ctx.unsafe_is_prev {
+        if ctx.has_item_list_or_source_file_parent || ctx.block_expr_parent {
+            add_keyword(ctx, acc, "fn", "fn $0() {}")
+        }
+
+        if (ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent)
+            || ctx.block_expr_parent
+        {
+            add_keyword(ctx, acc, "trait", "trait $0 {}");
+            add_keyword(ctx, acc, "impl", "impl $0 {}");
+        }
+
+        return;
+    }
+    if ctx.has_item_list_or_source_file_parent || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "fn", "fn $0() {}");
+    }
+    if (ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent)
+        || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "use", "use ");
+        add_keyword(ctx, acc, "impl", "impl $0 {}");
+        add_keyword(ctx, acc, "trait", "trait $0 {}");
+    }
+
+    if ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent {
+        add_keyword(ctx, acc, "enum", "enum $0 {}");
+        add_keyword(ctx, acc, "struct", "struct $0");
+        add_keyword(ctx, acc, "union", "union $0 {}");
+    }
+
+    if ctx.is_expr {
+        add_keyword(ctx, acc, "match", "match $0 {}");
+        add_keyword(ctx, acc, "while", "while $0 {}");
+        add_keyword(ctx, acc, "loop", "loop {$0}");
+        add_keyword(ctx, acc, "if", "if ");
+        add_keyword(ctx, acc, "if let", "if let ");
+    }
+
+    if ctx.if_is_prev || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "let", "let ");
+    }
 
     if ctx.after_if {
-        acc.add(keyword(ctx, "else", "else {$0}"));
-        acc.add(keyword(ctx, "else if", "else if $0 {}"));
+        add_keyword(ctx, acc, "else", "else {$0}");
+        add_keyword(ctx, acc, "else if", "else if $0 {}");
+    }
+    if (ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent)
+        || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "mod", "mod $0 {}");
+    }
+    if ctx.bind_pat_parent || ctx.ref_pat_parent {
+        add_keyword(ctx, acc, "mut", "mut ");
+    }
+    if ctx.has_item_list_or_source_file_parent || ctx.block_expr_parent {
+        add_keyword(ctx, acc, "const", "const ");
+        add_keyword(ctx, acc, "type", "type ");
+    }
+    if (ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent)
+        || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "static", "static ");
+    };
+    if (ctx.has_item_list_or_source_file_parent && !has_trait_or_impl_parent)
+        || ctx.block_expr_parent
+    {
+        add_keyword(ctx, acc, "extern", "extern ");
+    }
+    if ctx.has_item_list_or_source_file_parent || ctx.block_expr_parent || ctx.is_match_arm {
+        add_keyword(ctx, acc, "unsafe", "unsafe ");
     }
-    if is_in_loop_body(&ctx.token) {
+    if ctx.in_loop_body {
         if ctx.can_be_stmt {
-            acc.add(keyword(ctx, "continue", "continue;"));
-            acc.add(keyword(ctx, "break", "break;"));
+            add_keyword(ctx, acc, "continue", "continue;");
+            add_keyword(ctx, acc, "break", "break;");
         } else {
-            acc.add(keyword(ctx, "continue", "continue"));
-            acc.add(keyword(ctx, "break", "break"));
+            add_keyword(ctx, acc, "continue", "continue");
+            add_keyword(ctx, acc, "break", "break");
         }
     }
+    if ctx.has_item_list_or_source_file_parent && !ctx.has_trait_parent {
+        add_keyword(ctx, acc, "pub", "pub ")
+    }
+
+    if !ctx.is_trivial_path {
+        return;
+    }
+    let fn_def = match &ctx.function_syntax {
+        Some(it) => it,
+        None => return,
+    };
     acc.add_all(complete_return(ctx, &fn_def, ctx.can_be_stmt));
 }
 
-fn is_in_loop_body(leaf: &SyntaxToken) -> bool {
-    // FIXME move this to CompletionContext and make it handle macros
-    for node in leaf.parent().ancestors() {
-        if node.kind() == FN_DEF || node.kind() == LAMBDA_EXPR {
-            break;
-        }
-        let loop_body = match_ast! {
-            match node {
-                ast::ForExpr(it) => it.loop_body(),
-                ast::WhileExpr(it) => it.loop_body(),
-                ast::LoopExpr(it) => it.loop_body(),
-                _ => None,
-            }
-        };
-        if let Some(body) = loop_body {
-            if body.syntax().text_range().contains_range(leaf.text_range()) {
-                return true;
-            }
-        }
+fn keyword(ctx: &CompletionContext, kw: &str, snippet: &str) -> CompletionItem {
+    let res = CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), kw)
+        .kind(CompletionItemKind::Keyword);
+
+    match ctx.config.snippet_cap {
+        Some(cap) => res.insert_snippet(cap, snippet),
+        _ => res.insert_text(if snippet.contains('$') { kw } else { snippet }),
     }
-    false
+    .build()
+}
+
+fn add_keyword(ctx: &CompletionContext, acc: &mut Completions, kw: &str, snippet: &str) {
+    acc.add(keyword(ctx, kw, snippet));
 }
 
 fn complete_return(
@@ -121,666 +187,354 @@ fn complete_return(
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
+
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+    use test_utils::mark;
 
-    fn do_keyword_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Keyword)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Keyword);
+        expect.assert_eq(&actual)
     }
 
     #[test]
-    fn completes_keywords_in_use_stmt() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                use <|>
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "crate",
-                source_range: 21..21,
-                delete: 21..21,
-                insert: "crate::",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "self",
-                source_range: 21..21,
-                delete: 21..21,
-                insert: "self",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "super",
-                source_range: 21..21,
-                delete: 21..21,
-                insert: "super::",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_in_use_stmt() {
+        check(
+            r"use <|>",
+            expect![[r#"
+                kw crate::
+                kw self
+                kw super::
+            "#]],
         );
 
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                use a::<|>
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "self",
-                source_range: 24..24,
-                delete: 24..24,
-                insert: "self",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "super",
-                source_range: 24..24,
-                delete: 24..24,
-                insert: "super::",
-                kind: Keyword,
-            },
-        ]
-        "###
+        check(
+            r"use a::<|>",
+            expect![[r#"
+                kw self
+                kw super::
+            "#]],
         );
 
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                use a::{b, <|>}
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "self",
-                source_range: 28..28,
-                delete: 28..28,
-                insert: "self",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "super",
-                source_range: 28..28,
-                delete: 28..28,
-                insert: "super::",
-                kind: Keyword,
-            },
-        ]
-        "###
+        check(
+            r"use a::{b, <|>}",
+            expect![[r#"
+                kw self
+                kw super::
+            "#]],
         );
     }
 
     #[test]
-    fn completes_various_keywords_in_function() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() {
-                    <|>
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "return;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_at_source_file_level() {
+        check(
+            r"m<|>",
+            expect![[r#"
+                kw const
+                kw enum
+                kw extern
+                kw fn
+                kw impl
+                kw mod
+                kw pub
+                kw static
+                kw struct
+                kw trait
+                kw type
+                kw union
+                kw unsafe
+                kw use
+            "#]],
         );
     }
 
     #[test]
-    fn completes_else_after_if() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() {
-                    if true {
-                        ()
-                    } <|>
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "else",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "else {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "else if",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "else if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "if",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "return;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 108..108,
-                delete: 108..108,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_in_function() {
+        check(
+            r"fn quux() { <|> }",
+            expect![[r#"
+                kw const
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
         );
     }
 
     #[test]
-    fn test_completion_return_value() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    <|>
-                    92
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 56..56,
-                delete: 56..56,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 56..56,
-                delete: 56..56,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 56..56,
-                delete: 56..56,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 56..56,
-                delete: 56..56,
-                insert: "return $0;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 56..56,
-                delete: 56..56,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_inside_block() {
+        check(
+            r"fn quux() { if true { <|> } }",
+            expect![[r#"
+                kw const
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
         );
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() {
-                    <|>
-                    92
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "return;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    }
+
+    #[test]
+    fn test_keywords_after_if() {
+        check(
+            r#"fn quux() { if true { () } <|> }"#,
+            expect![[r#"
+                kw const
+                kw else
+                kw else if
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
+        );
+        check_edit(
+            "else",
+            r#"fn quux() { if true { () } <|> }"#,
+            r#"fn quux() { if true { () } else {$0} }"#,
         );
     }
 
     #[test]
-    fn dont_add_semi_after_return_if_not_a_statement() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    match () {
-                        () => <|>
-                    }
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 97..97,
-                delete: 97..97,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 97..97,
-                delete: 97..97,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 97..97,
-                delete: 97..97,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 97..97,
-                delete: 97..97,
-                insert: "return $0",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 97..97,
-                delete: 97..97,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_in_match_arm() {
+        check(
+            r#"
+fn quux() -> i32 {
+    match () { () => <|> }
+}
+"#,
+            expect![[r#"
+                kw if
+                kw if let
+                kw loop
+                kw match
+                kw return
+                kw unsafe
+                kw while
+            "#]],
         );
     }
 
     #[test]
-    fn last_return_in_block_has_semi() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    if condition {
-                        <|>
-                    }
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "return $0;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_in_trait_def() {
+        check(
+            r"trait My { <|> }",
+            expect![[r#"
+                kw const
+                kw fn
+                kw type
+                kw unsafe
+            "#]],
         );
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    if condition {
-                        <|>
-                    }
-                    let x = 92;
-                    x
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "return $0;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    }
+
+    #[test]
+    fn test_keywords_in_impl_def() {
+        check(
+            r"impl My { <|> }",
+            expect![[r#"
+                kw const
+                kw fn
+                kw pub
+                kw type
+                kw unsafe
+            "#]],
         );
     }
 
     #[test]
-    fn completes_break_and_continue_in_loops() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    loop { <|> }
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "break",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "break;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "continue",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "continue;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "if",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "return $0;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 63..63,
-                delete: 63..63,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_in_loop() {
+        check(
+            r"fn my() { loop { <|> } }",
+            expect![[r#"
+                kw break
+                kw const
+                kw continue
+                kw extern
+                kw fn
+                kw if
+                kw if let
+                kw impl
+                kw let
+                kw loop
+                kw match
+                kw mod
+                kw return
+                kw static
+                kw trait
+                kw type
+                kw unsafe
+                kw use
+                kw while
+            "#]],
         );
+    }
 
-        // No completion: lambda isolates control flow
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn quux() -> i32 {
-                    loop { || { <|> } }
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "if",
-                source_range: 68..68,
-                delete: 68..68,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 68..68,
-                delete: 68..68,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 68..68,
-                delete: 68..68,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 68..68,
-                delete: 68..68,
-                insert: "return $0;",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 68..68,
-                delete: 68..68,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    #[test]
+    fn test_keywords_after_unsafe_in_item_list() {
+        check(
+            r"unsafe <|>",
+            expect![[r#"
+                kw fn
+                kw impl
+                kw trait
+            "#]],
         );
     }
 
     #[test]
-    fn no_semi_after_break_continue_in_expr() {
-        assert_debug_snapshot!(
-            do_keyword_completion(
-                r"
-                fn f() {
-                    loop {
-                        match () {
-                            () => br<|>
-                        }
-                    }
-                }
-                ",
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "break",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "break",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "continue",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "continue",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "if",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "if $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "loop",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "loop {$0}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "match $0 {}",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "return",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "return",
-                kind: Keyword,
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 122..124,
-                delete: 122..124,
-                insert: "while $0 {}",
-                kind: Keyword,
-            },
-        ]
-        "###
+    fn test_keywords_after_unsafe_in_block_expr() {
+        check(
+            r"fn my_fn() { unsafe <|> }",
+            expect![[r#"
+                kw fn
+                kw impl
+                kw trait
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_mut_in_ref_and_in_fn_parameters_list() {
+        check(
+            r"fn my_fn(&<|>) {}",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+        check(
+            r"fn my_fn(<|>) {}",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+        check(
+            r"fn my_fn() { let &<|> }",
+            expect![[r#"
+                kw mut
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_where_keyword() {
+        check(
+            r"trait A <|>",
+            expect![[r#"
+                kw where
+            "#]],
+        );
+        check(
+            r"impl A <|>",
+            expect![[r#"
+                kw where
+            "#]],
+        );
+    }
+
+    #[test]
+    fn no_keyword_completion_in_comments() {
+        mark::check!(no_keyword_completion_in_comments);
+        check(
+            r#"
+fn test() {
+    let x = 2; // A comment<|>
+}
+"#,
+            expect![[""]],
+        );
+        check(
+            r#"
+/*
+Some multi-line comment<|>
+*/
+"#,
+            expect![[""]],
+        );
+        check(
+            r#"
+/// Some doc comment
+/// let test<|> = 1
+"#,
+            expect![[""]],
+        );
+    }
+
+    #[test]
+    fn test_completion_await_impls_future() {
+        check(
+            r#"
+//- /main.rs
+use std::future::*;
+struct A {}
+impl Future for A {}
+fn foo(a: A) { a.<|> }
+
+//- /std/lib.rs
+pub mod future {
+    #[lang = "future_trait"]
+    pub trait Future {}
+}
+"#,
+            expect![[r#"
+                kw await expr.await
+            "#]],
+        )
+    }
+
+    #[test]
+    fn after_let() {
+        check(
+            r#"fn main() { let _ = <|> }"#,
+            expect![[r#"
+                kw if
+                kw if let
+                kw loop
+                kw match
+                kw return
+                kw while
+            "#]],
         )
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_macro_in_item_position.rs b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
index d9bb5fd25..0447f0511 100644
--- a/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
+++ b/crates/ra_ide/src/completion/complete_macro_in_item_position.rs
@@ -5,7 +5,7 @@ use crate::completion::{CompletionContext, Completions};
 pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &CompletionContext) {
     // Show only macros in top level.
     if ctx.is_new_item {
-        ctx.scope().process_all_names(&mut |name, res| {
+        ctx.scope.process_all_names(&mut |name, res| {
             if let hir::ScopeDef::MacroDef(mac) = res {
                 acc.add_macro(ctx, Some(name.to_string()), mac);
             }
@@ -15,130 +15,27 @@ pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &Compl
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    use crate::completion::{test_utils::completion_list, CompletionKind};
 
-    fn do_reference_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Reference)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn completes_macros_as_item() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                macro_rules! foo {
-                    () => {}
-                }
-
-                fn foo() {}
-
-                <|>
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 46..46,
-                delete: 46..46,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "macro_rules! foo",
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn completes_vec_macros_with_square_brackets() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                /// Creates a [`Vec`] containing the arguments.
-                ///
-                /// - Create a [`Vec`] containing a given list of elements:
-                ///
-                /// ```
-                /// let v = vec![1, 2, 3];
-                /// assert_eq!(v[0], 1);
-                /// assert_eq!(v[1], 2);
-                /// assert_eq!(v[2], 3);
-                /// ```
-                macro_rules! vec {
-                    () => {}
-                }
-
-                fn foo() {}
-
-                <|>
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "vec![…]",
-                source_range: 280..280,
-                delete: 280..280,
-                insert: "vec![$0]",
-                kind: Macro,
-                detail: "macro_rules! vec",
-                documentation: Documentation(
-                    "Creates a [`Vec`] containing the arguments.\n\n- Create a [`Vec`] containing a given list of elements:\n\n```\nlet v = vec![1, 2, 3];\nassert_eq!(v[0], 1);\nassert_eq!(v[1], 2);\nassert_eq!(v[2], 3);\n```",
-                ),
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn completes_macros_braces_guessing() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                /// Foo
-                ///
-                /// Not call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`.
-                /// Call as `let _=foo!  { hello world };`
-                macro_rules! foo {
-                    () => {}
-                }
-
-                fn main() {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo! {…}",
-                source_range: 163..163,
-                delete: 163..163,
-                insert: "foo! {$0}",
-                kind: Macro,
-                detail: "macro_rules! foo",
-                documentation: Documentation(
-                    "Foo\n\nNot call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`.\nCall as `let _=foo!  { hello world };`",
-                ),
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 163..163,
-                delete: 163..163,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn foo() {}
+
+<|>
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+            "#]],
+        )
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_pattern.rs b/crates/ra_ide/src/completion/complete_pattern.rs
index fdd9e928b..aceb77cb5 100644
--- a/crates/ra_ide/src/completion/complete_pattern.rs
+++ b/crates/ra_ide/src/completion/complete_pattern.rs
@@ -13,7 +13,7 @@ pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
 
     // FIXME: ideally, we should look at the type we are matching against and
     // suggest variants + auto-imports
-    ctx.scope().process_all_names(&mut |name, res| {
+    ctx.scope.process_all_names(&mut |name, res| {
         match &res {
             hir::ScopeDef::ModuleDef(def) => match def {
                 hir::ModuleDef::Adt(hir::Adt::Enum(..))
@@ -33,106 +33,56 @@ pub(super) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    fn complete(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Reference)
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn completes_enum_variants_and_modules() {
-        let completions = complete(
-            r"
-            enum E { X }
-            use self::E::X;
-            const Z: E = E::X;
-            mod m {}
+        check(
+            r#"
+enum E { X }
+use self::E::X;
+const Z: E = E::X;
+mod m {}
 
-            static FOO: E = E::X;
-            struct Bar { f: u32 }
+static FOO: E = E::X;
+struct Bar { f: u32 }
 
-            fn foo() {
-               match E::X {
-                   <|>
-               }
-            }
-            ",
+fn foo() {
+   match E::X { <|> }
+}
+"#,
+            expect![[r#"
+                st Bar
+                en E
+                ev X   ()
+                ct Z
+                md m
+            "#]],
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "Bar",
-                source_range: 246..246,
-                delete: 246..246,
-                insert: "Bar",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "E",
-                source_range: 246..246,
-                delete: 246..246,
-                insert: "E",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "X",
-                source_range: 246..246,
-                delete: 246..246,
-                insert: "X",
-                kind: EnumVariant,
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Z",
-                source_range: 246..246,
-                delete: 246..246,
-                insert: "Z",
-                kind: Const,
-            },
-            CompletionItem {
-                label: "m",
-                source_range: 246..246,
-                delete: 246..246,
-                insert: "m",
-                kind: Module,
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn completes_in_simple_macro_call() {
-        let completions = complete(
-            r"
-            macro_rules! m { ($e:expr) => { $e } }
-            enum E { X }
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+enum E { X }
 
-            fn foo() {
-               m!(match E::X {
-                   <|>
-               })
-            }
-            ",
+fn foo() {
+   m!(match E::X { <|> })
+}
+"#,
+            expect![[r#"
+                en E
+                ma m!(…) macro_rules! m
+            "#]],
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "E",
-                source_range: 151..151,
-                delete: 151..151,
-                insert: "E",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "m!(…)",
-                source_range: 151..151,
-                delete: 151..151,
-                insert: "m!($0)",
-                kind: Macro,
-                detail: "macro_rules! m",
-            },
-        ]
-        "###);
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_postfix.rs b/crates/ra_ide/src/completion/complete_postfix.rs
index 59b58bf98..8735b9010 100644
--- a/crates/ra_ide/src/completion/complete_postfix.rs
+++ b/crates/ra_ide/src/completion/complete_postfix.rs
@@ -8,14 +8,13 @@ use ra_text_edit::TextEdit;
 
 use crate::{
     completion::{
+        completion_config::SnippetCap,
         completion_context::CompletionContext,
         completion_item::{Builder, CompletionKind, Completions},
     },
-    CompletionItem,
+    CompletionItem, CompletionItemKind,
 };
 
-use super::completion_config::SnippetCap;
-
 pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.config.enable_postfix_completions {
         return;
@@ -91,7 +90,7 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
             &dot_receiver,
             "if",
             "if expr {}",
-            &format!("if {} {{$0}}", receiver_text),
+            &format!("if {} {{\n    $0\n}}", receiver_text),
         )
         .add_to(acc);
         postfix_snippet(
@@ -100,13 +99,12 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
             &dot_receiver,
             "while",
             "while expr {}",
-            &format!("while {} {{\n$0\n}}", receiver_text),
+            &format!("while {} {{\n    $0\n}}", receiver_text),
         )
         .add_to(acc);
+        postfix_snippet(ctx, cap, &dot_receiver, "not", "!expr", &format!("!{}", receiver_text))
+            .add_to(acc);
     }
-    // !&&&42 is a compiler error, ergo process it before considering the references
-    postfix_snippet(ctx, cap, &dot_receiver, "not", "!expr", &format!("!{}", receiver_text))
-        .add_to(acc);
 
     postfix_snippet(ctx, cap, &dot_receiver, "ref", "&expr", &format!("&{}", receiver_text))
         .add_to(acc);
@@ -125,33 +123,35 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     let dot_receiver = include_references(dot_receiver);
     let receiver_text =
         get_receiver_text(&dot_receiver, ctx.dot_receiver_is_ambiguous_float_literal);
+
     match try_enum {
-        Some(try_enum) => {
-            match try_enum {
-                TryEnum::Result => {
-                    postfix_snippet(
+        Some(try_enum) => match try_enum {
+            TryEnum::Result => {
+                postfix_snippet(
                     ctx,
                     cap,
                     &dot_receiver,
                     "match",
                     "match expr {}",
-                    &format!("match {} {{\n    Ok(${{1:_}}) => {{$2\\}},\n    Err(${{3:_}}) => {{$0\\}},\n}}", receiver_text),
+                    &format!("match {} {{\n    Ok(${{1:_}}) => {{$2}},\n    Err(${{3:_}}) => {{$0}},\n}}", receiver_text),
                 )
                 .add_to(acc);
-                }
-                TryEnum::Option => {
-                    postfix_snippet(
+            }
+            TryEnum::Option => {
+                postfix_snippet(
                     ctx,
                     cap,
                     &dot_receiver,
                     "match",
                     "match expr {}",
-                    &format!("match {} {{\n    Some(${{1:_}}) => {{$2\\}},\n    None => {{$0\\}},\n}}", receiver_text),
+                    &format!(
+                        "match {} {{\n    Some(${{1:_}}) => {{$2}},\n    None => {{$0}},\n}}",
+                        receiver_text
+                    ),
                 )
                 .add_to(acc);
-                }
             }
-        }
+        },
         None => {
             postfix_snippet(
                 ctx,
@@ -159,7 +159,7 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
                 &dot_receiver,
                 "match",
                 "match expr {}",
-                &format!("match {} {{\n    ${{1:_}} => {{$0\\}},\n}}", receiver_text),
+                &format!("match {} {{\n    ${{1:_}} => {{$0}},\n}}", receiver_text),
             )
             .add_to(acc);
         }
@@ -232,536 +232,147 @@ fn postfix_snippet(
     };
     CompletionItem::new(CompletionKind::Postfix, ctx.source_range(), label)
         .detail(detail)
+        .kind(CompletionItemKind::Snippet)
         .snippet_edit(cap, edit)
 }
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
 
-    fn do_postfix_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Postfix)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Postfix);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn postfix_completion_works_for_trivial_path_expression() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                fn main() {
-                    let bar = true;
-                    bar.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "Box::new(bar)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "${1}(bar)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "dbg!(bar)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "if",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "if bar {$0}",
-                detail: "if expr {}",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "match bar {\n    ${1:_} => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "!bar",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "&bar",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "&mut bar",
-                detail: "&mut expr",
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 89..89,
-                delete: 85..89,
-                insert: "while bar {\n$0\n}",
-                detail: "while expr {}",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn main() {
+    let bar = true;
+    bar.<|>
+}
+"#,
+            expect![[r#"
+                sn box   Box::new(expr)
+                sn call  function(expr)
+                sn dbg   dbg!(expr)
+                sn if    if expr {}
+                sn match match expr {}
+                sn not   !expr
+                sn ref   &expr
+                sn refm  &mut expr
+                sn while while expr {}
+            "#]],
         );
     }
 
     #[test]
-    fn postfix_completion_works_for_option() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                enum Option<T> {
-                    Some(T),
-                    None,
-                }
-
-                fn main() {
-                    let bar = Option::Some(true);
-                    bar.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "Box::new(bar)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "${1}(bar)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "dbg!(bar)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "ifl",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "if let Some($1) = bar {\n    $0\n}",
-                detail: "if let Some {}",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "match bar {\n    Some(${1:_}) => {$2\\},\n    None => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "!bar",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "&bar",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "&mut bar",
-                detail: "&mut expr",
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 210..210,
-                delete: 206..210,
-                insert: "while let Some($1) = bar {\n    $0\n}",
-                detail: "while let Some {}",
-            },
-        ]
-        "###
-        );
+    fn postfix_type_filtering() {
+        check(
+            r#"
+fn main() {
+    let bar: u8 = 12;
+    bar.<|>
+}
+"#,
+            expect![[r#"
+                sn box   Box::new(expr)
+                sn call  function(expr)
+                sn dbg   dbg!(expr)
+                sn match match expr {}
+                sn ref   &expr
+                sn refm  &mut expr
+            "#]],
+        )
     }
 
     #[test]
-    fn postfix_completion_works_for_result() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                enum Result<T, E> {
-                    Ok(T),
-                    Err(E),
-                }
+    fn option_iflet() {
+        check_edit(
+            "ifl",
+            r#"
+enum Option<T> { Some(T), None }
+
+fn main() {
+    let bar = Option::Some(true);
+    bar.<|>
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
 
-                fn main() {
-                    let bar = Result::Ok(true);
-                    bar.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "Box::new(bar)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "${1}(bar)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "dbg!(bar)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "ifl",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "if let Ok($1) = bar {\n    $0\n}",
-                detail: "if let Ok {}",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "match bar {\n    Ok(${1:_}) => {$2\\},\n    Err(${3:_}) => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "!bar",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "&bar",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "&mut bar",
-                detail: "&mut expr",
-            },
-            CompletionItem {
-                label: "while",
-                source_range: 211..211,
-                delete: 207..211,
-                insert: "while let Ok($1) = bar {\n    $0\n}",
-                detail: "while let Ok {}",
-            },
-        ]
-        "###
+fn main() {
+    let bar = Option::Some(true);
+    if let Some($1) = bar {
+    $0
+}
+}
+"#,
         );
     }
 
     #[test]
-    fn some_postfix_completions_ignored() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                fn main() {
-                    let bar: u8 = 12;
-                    bar.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "Box::new(bar)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "${1}(bar)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "dbg!(bar)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "match bar {\n    ${1:_} => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "!bar",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "&bar",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 91..91,
-                delete: 87..91,
-                insert: "&mut bar",
-                detail: "&mut expr",
-            },
-        ]
-        "###
+    fn result_match() {
+        check_edit(
+            "match",
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+
+fn main() {
+    let bar = Result::Ok(true);
+    bar.<|>
+}
+"#,
+            r#"
+enum Result<T, E> { Ok(T), Err(E) }
+
+fn main() {
+    let bar = Result::Ok(true);
+    match bar {
+    Ok(${1:_}) => {$2},
+    Err(${3:_}) => {$0},
+}
+}
+"#,
         );
     }
 
     #[test]
     fn postfix_completion_works_for_ambiguous_float_literal() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                fn main() {
-                    42.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "Box::new(42)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "${1}(42)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "dbg!(42)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "match 42 {\n    ${1:_} => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "!42",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "&42",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 52..52,
-                delete: 49..52,
-                insert: "&mut 42",
-                detail: "&mut expr",
-            },
-        ]
-        "###
-        );
+        check_edit("refm", r#"fn main() { 42.<|> }"#, r#"fn main() { &mut 42 }"#)
     }
 
     #[test]
     fn works_in_simple_macro() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                macro_rules! m { ($e:expr) => { $e } }
-                fn main() {
-                    let bar: u8 = 12;
-                    m!(bar.b<|>)
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "Box::new(bar)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "${1}(bar)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "dbg!(bar)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "match bar {\n    ${1:_} => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "!bar",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "&bar",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 149..150,
-                delete: 145..150,
-                insert: "&mut bar",
-                detail: "&mut expr",
-            },
-        ]
-        "###
+        check_edit(
+            "dbg",
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn main() {
+    let bar: u8 = 12;
+    m!(bar.d<|>)
+}
+"#,
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn main() {
+    let bar: u8 = 12;
+    m!(dbg!(bar))
+}
+"#,
         );
     }
 
     #[test]
     fn postfix_completion_for_references() {
-        assert_debug_snapshot!(
-            do_postfix_completion(
-                r#"
-                fn main() {
-                    &&&&42.<|>
-                }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "box",
-                source_range: 56..56,
-                delete: 49..56,
-                insert: "Box::new(&&&&42)",
-                detail: "Box::new(expr)",
-            },
-            CompletionItem {
-                label: "call",
-                source_range: 56..56,
-                delete: 49..56,
-                insert: "${1}(&&&&42)",
-                detail: "function(expr)",
-            },
-            CompletionItem {
-                label: "dbg",
-                source_range: 56..56,
-                delete: 49..56,
-                insert: "dbg!(&&&&42)",
-                detail: "dbg!(expr)",
-            },
-            CompletionItem {
-                label: "match",
-                source_range: 56..56,
-                delete: 49..56,
-                insert: "match &&&&42 {\n    ${1:_} => {$0\\},\n}",
-                detail: "match expr {}",
-            },
-            CompletionItem {
-                label: "not",
-                source_range: 56..56,
-                delete: 53..56,
-                insert: "!42",
-                detail: "!expr",
-            },
-            CompletionItem {
-                label: "ref",
-                source_range: 56..56,
-                delete: 53..56,
-                insert: "&42",
-                detail: "&expr",
-            },
-            CompletionItem {
-                label: "refm",
-                source_range: 56..56,
-                delete: 53..56,
-                insert: "&mut 42",
-                detail: "&mut expr",
-            },
-        ]
-        "###
-        );
+        check_edit("dbg", r#"fn main() { &&42.<|> }"#, r#"fn main() { dbg!(&&42) }"#);
+        check_edit("refm", r#"fn main() { &&42.<|> }"#, r#"fn main() { &&&mut 42 }"#);
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_qualified_path.rs b/crates/ra_ide/src/completion/complete_qualified_path.rs
index 02ac0166b..b08f5b9b4 100644
--- a/crates/ra_ide/src/completion/complete_qualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_qualified_path.rs
@@ -17,21 +17,20 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
         return;
     }
 
-    let scope = ctx.scope();
-    let context_module = scope.module();
+    let context_module = ctx.scope.module();
 
-    let res = match scope.resolve_hir_path_qualifier(&path) {
+    let resolution = match ctx.scope.resolve_hir_path_qualifier(&path) {
         Some(res) => res,
         None => return,
     };
 
     // Add associated types on type parameters and `Self`.
-    res.assoc_type_shorthand_candidates(ctx.db, |alias| {
+    resolution.assoc_type_shorthand_candidates(ctx.db, |alias| {
         acc.add_type_alias(ctx, alias);
         None::<()>
     });
 
-    match res {
+    match resolution {
         PathResolution::Def(hir::ModuleDef::Module(module)) => {
             let module_scope = module.scope(ctx.db, context_module);
             for (name, def) in module_scope {
@@ -68,7 +67,7 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 
             let krate = ctx.krate;
             if let Some(krate) = krate {
-                let traits_in_scope = ctx.scope().traits_in_scope();
+                let traits_in_scope = ctx.scope.traits_in_scope();
                 ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
                         return None;
@@ -113,13 +112,13 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
         }
         PathResolution::TypeParam(_) | PathResolution::SelfType(_) => {
             if let Some(krate) = ctx.krate {
-                let ty = match res {
+                let ty = match resolution {
                     PathResolution::TypeParam(param) => param.ty(ctx.db),
                     PathResolution::SelfType(impl_def) => impl_def.target_ty(ctx.db),
                     _ => return,
                 };
 
-                let traits_in_scope = ctx.scope().traits_in_scope();
+                let traits_in_scope = ctx.scope.traits_in_scope();
                 let mut seen = FxHashSet::default();
                 ty.iterate_path_candidates(ctx.db, krate, &traits_in_scope, None, |_ty, item| {
                     if context_module.map_or(false, |m| !item.is_visible_from(ctx.db, m)) {
@@ -147,1229 +146,588 @@ pub(super) fn complete_qualified_path(acc: &mut Completions, ctx: &CompletionCon
 
 #[cfg(test)]
 mod tests {
+    use expect::{expect, Expect};
     use test_utils::mark;
 
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
+    }
 
-    fn do_reference_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Reference)
+    fn check_builtin(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::BuiltinType);
+        expect.assert_eq(&actual);
     }
 
     #[test]
     fn dont_complete_current_use() {
         mark::check!(dont_complete_current_use);
-        let completions = do_completion(r"use self::foo<|>;", CompletionKind::Reference);
-        assert!(completions.is_empty());
+        check(r#"use self::foo<|>;"#, expect![[""]]);
     }
 
     #[test]
     fn dont_complete_current_use_in_braces_with_glob() {
-        let completions = do_completion(
-            r"
-            mod foo { pub struct S; }
-            use self::{foo::*, bar<|>};
-            ",
-            CompletionKind::Reference,
+        check(
+            r#"
+mod foo { pub struct S; }
+use self::{foo::*, bar<|>};
+"#,
+            expect![[r#"
+                st S
+                md foo
+            "#]],
         );
-        assert_eq!(completions.len(), 2);
     }
 
     #[test]
     fn dont_complete_primitive_in_use() {
-        let completions = do_completion(r"use self::<|>;", CompletionKind::BuiltinType);
-        assert!(completions.is_empty());
+        check_builtin(r#"use self::<|>;"#, expect![[""]]);
     }
 
     #[test]
     fn dont_complete_primitive_in_module_scope() {
-        let completions = do_completion(r"fn foo() { self::<|> }", CompletionKind::BuiltinType);
-        assert!(completions.is_empty());
+        check_builtin(r#"fn foo() { self::<|> }"#, expect![[""]]);
     }
 
     #[test]
     fn completes_primitives() {
-        let completions =
-            do_completion(r"fn main() { let _: <|> = 92; }", CompletionKind::BuiltinType);
-        assert_eq!(completions.len(), 17);
-    }
-
-    #[test]
-    fn completes_mod_with_docs() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                use self::my<|>;
-
-                /// Some simple
-                /// docs describing `mod my`.
-                mod my {
-                    struct Bar;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "my",
-                source_range: 27..29,
-                delete: 27..29,
-                insert: "my",
-                kind: Module,
-                documentation: Documentation(
-                    "Some simple\ndocs describing `mod my`.",
-                ),
-            },
-        ]
-        "###
+        check_builtin(
+            r#"fn main() { let _: <|> = 92; }"#,
+            expect![[r#"
+                bt bool
+                bt char
+                bt f32
+                bt f64
+                bt i128
+                bt i16
+                bt i32
+                bt i64
+                bt i8
+                bt isize
+                bt str
+                bt u128
+                bt u16
+                bt u32
+                bt u64
+                bt u8
+                bt usize
+            "#]],
         );
     }
 
     #[test]
     fn completes_mod_with_same_name_as_function() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                use self::my::<|>;
-
-                mod my {
-                    pub struct Bar;
-                }
-
-                fn my() {}
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Bar",
-                source_range: 31..31,
-                delete: 31..31,
-                insert: "Bar",
-                kind: Struct,
-            },
-        ]
-        "###
+        check(
+            r#"
+use self::my::<|>;
+
+mod my { pub struct Bar; }
+fn my() {}
+"#,
+            expect![[r#"
+                st Bar
+            "#]],
         );
     }
 
     #[test]
-    fn path_visibility() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                use self::my::<|>;
-
-                mod my {
-                    struct Bar;
-                    pub struct Foo;
-                    pub use Bar as PublicBar;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 31..31,
-                delete: 31..31,
-                insert: "Foo",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "PublicBar",
-                source_range: 31..31,
-                delete: 31..31,
-                insert: "PublicBar",
-                kind: Struct,
-            },
-        ]
-        "###
+    fn filters_visibility() {
+        check(
+            r#"
+use self::my::<|>;
+
+mod my {
+    struct Bar;
+    pub struct Foo;
+    pub use Bar as PublicBar;
+}
+"#,
+            expect![[r#"
+                st Foo
+                st PublicBar
+            "#]],
         );
     }
 
     #[test]
     fn completes_use_item_starting_with_self() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                use self::m::<|>;
+        check(
+            r#"
+use self::m::<|>;
 
-                mod m {
-                    pub struct Bar;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Bar",
-                source_range: 30..30,
-                delete: 30..30,
-                insert: "Bar",
-                kind: Struct,
-            },
-        ]
-        "###
+mod m { pub struct Bar; }
+"#,
+            expect![[r#"
+                st Bar
+            "#]],
         );
     }
 
     #[test]
     fn completes_use_item_starting_with_crate() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                mod foo;
-                struct Spam;
-                //- /foo.rs
-                use crate::Sp<|>
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Spam",
-                source_range: 11..13,
-                delete: 11..13,
-                insert: "Spam",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "foo",
-                source_range: 11..13,
-                delete: 11..13,
-                insert: "foo",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+struct Spam;
+//- /foo.rs
+use crate::Sp<|>
+"#,
+            expect![[r#"
+                st Spam
+                md foo
+            "#]],
         );
     }
 
     #[test]
     fn completes_nested_use_tree() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                mod foo;
-                struct Spam;
-                //- /foo.rs
-                use crate::{Sp<|>};
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Spam",
-                source_range: 12..14,
-                delete: 12..14,
-                insert: "Spam",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "foo",
-                source_range: 12..14,
-                delete: 12..14,
-                insert: "foo",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+struct Spam;
+//- /foo.rs
+use crate::{Sp<|>};
+"#,
+            expect![[r#"
+                st Spam
+                md foo
+            "#]],
         );
     }
 
     #[test]
     fn completes_deeply_nested_use_tree() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                mod foo;
-                pub mod bar {
-                    pub mod baz {
-                        pub struct Spam;
-                    }
-                }
-                //- /foo.rs
-                use crate::{bar::{baz::Sp<|>}};
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Spam",
-                source_range: 23..25,
-                delete: 23..25,
-                insert: "Spam",
-                kind: Struct,
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn completes_enum_variant() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// An enum
-                enum E {
-                    /// Foo Variant
-                    Foo,
-                    /// Bar Variant with i32
-                    Bar(i32)
-                }
-                fn foo() { let _ = E::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Bar(…)",
-                source_range: 116..116,
-                delete: 116..116,
-                insert: "Bar($0)",
-                kind: EnumVariant,
-                lookup: "Bar",
-                detail: "(i32)",
-                documentation: Documentation(
-                    "Bar Variant with i32",
-                ),
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "Foo",
-                source_range: 116..116,
-                delete: 116..116,
-                insert: "Foo",
-                kind: EnumVariant,
-                detail: "()",
-                documentation: Documentation(
-                    "Foo Variant",
-                ),
-            },
-        ]
-        "###
-        );
-    }
-
-    #[test]
-    fn completes_enum_variant_with_details() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                struct S { field: u32 }
-                /// An enum
-                enum E {
-                    /// Foo Variant (empty)
-                    Foo,
-                    /// Bar Variant with i32 and u32
-                    Bar(i32, u32),
-                    ///
-                    S(S),
-                }
-                fn foo() { let _ = E::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Bar(…)",
-                source_range: 180..180,
-                delete: 180..180,
-                insert: "Bar($0)",
-                kind: EnumVariant,
-                lookup: "Bar",
-                detail: "(i32, u32)",
-                documentation: Documentation(
-                    "Bar Variant with i32 and u32",
-                ),
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "Foo",
-                source_range: 180..180,
-                delete: 180..180,
-                insert: "Foo",
-                kind: EnumVariant,
-                detail: "()",
-                documentation: Documentation(
-                    "Foo Variant (empty)",
-                ),
-            },
-            CompletionItem {
-                label: "S(…)",
-                source_range: 180..180,
-                delete: 180..180,
-                insert: "S($0)",
-                kind: EnumVariant,
-                lookup: "S",
-                detail: "(S)",
-                documentation: Documentation(
-                    "",
-                ),
-                trigger_call_info: true,
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+//- /lib.rs
+mod foo;
+pub mod bar {
+    pub mod baz {
+        pub struct Spam;
     }
-
-    #[test]
-    fn completes_struct_associated_method() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// A Struct
-                struct S;
-
-                impl S {
-                    /// An associated method
-                    fn m() { }
-                }
-
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 100..100,
-                delete: 100..100,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "An associated method",
-                ),
-            },
-        ]
-        "###
+}
+//- /foo.rs
+use crate::{bar::{baz::Sp<|>}};
+"#,
+            expect![[r#"
+                st Spam
+            "#]],
         );
     }
 
     #[test]
-    fn completes_struct_associated_method_with_self() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// A Struct
-                struct S;
-
-                impl S {
-                    /// An associated method
-                    fn m(&self) { }
-                }
-
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 105..105,
-                delete: 105..105,
-                insert: "m()$0",
-                kind: Method,
-                lookup: "m",
-                detail: "fn m(&self)",
-                documentation: Documentation(
-                    "An associated method",
-                ),
-            },
-        ]
-        "###
+    fn completes_enum_variant() {
+        check(
+            r#"
+enum E { Foo, Bar(i32) }
+fn foo() { let _ = E::<|> }
+"#,
+            expect![[r#"
+                ev Bar(…) (i32)
+                ev Foo    ()
+            "#]],
         );
     }
 
     #[test]
-    fn completes_struct_associated_const() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// A Struct
-                struct S;
-
-                impl S {
-                    /// An associated const
-                    const C: i32 = 42;
-                }
+    fn completes_struct_associated_items() {
+        check(
+            r#"
+//- /lib.rs
+struct S;
+
+impl S {
+    fn a() {}
+    fn b(&self) {}
+    const C: i32 = 42;
+    type T = i32;
+}
 
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "C",
-                source_range: 107..107,
-                delete: 107..107,
-                insert: "C",
-                kind: Const,
-                detail: "const C: i32 = 42;",
-                documentation: Documentation(
-                    "An associated const",
-                ),
-            },
-        ]
-        "###
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                ct C   const C: i32 = 42;
+                ta T   type T = i32;
+                fn a() fn a()
+                me b() fn b(&self)
+            "#]],
         );
     }
 
     #[test]
-    fn completes_struct_associated_type() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// A Struct
-                struct S;
-
-                impl S {
-                    /// An associated type
-                    type T = i32;
-                }
+    fn associated_item_visibility() {
+        check(
+            r#"
+struct S;
 
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "T",
-                source_range: 101..101,
-                delete: 101..101,
-                insert: "T",
-                kind: TypeAlias,
-                detail: "type T = i32;",
-                documentation: Documentation(
-                    "An associated type",
-                ),
-            },
-        ]
-        "###
-        );
+mod m {
+    impl super::S {
+        pub(super) fn public_method() { }
+        fn private_method() { }
+        pub(super) type PublicType = u32;
+        type PrivateType = u32;
+        pub(super) const PUBLIC_CONST: u32 = 1;
+        const PRIVATE_CONST: u32 = 1;
     }
+}
 
-    #[test]
-    fn associated_item_visibility() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                struct S;
-
-                mod m {
-                    impl super::S {
-                        pub(super) fn public_method() { }
-                        fn private_method() { }
-                        pub(super) type PublicType = u32;
-                        type PrivateType = u32;
-                        pub(super) const PUBLIC_CONST: u32 = 1;
-                        const PRIVATE_CONST: u32 = 1;
-                    }
-                }
-
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "PUBLIC_CONST",
-                source_range: 302..302,
-                delete: 302..302,
-                insert: "PUBLIC_CONST",
-                kind: Const,
-                detail: "pub(super) const PUBLIC_CONST: u32 = 1;",
-            },
-            CompletionItem {
-                label: "PublicType",
-                source_range: 302..302,
-                delete: 302..302,
-                insert: "PublicType",
-                kind: TypeAlias,
-                detail: "pub(super) type PublicType = u32;",
-            },
-            CompletionItem {
-                label: "public_method()",
-                source_range: 302..302,
-                delete: 302..302,
-                insert: "public_method()$0",
-                kind: Function,
-                lookup: "public_method",
-                detail: "pub(super) fn public_method()",
-            },
-        ]
-        "###
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                ct PUBLIC_CONST    pub(super) const PUBLIC_CONST: u32 = 1;
+                ta PublicType      pub(super) type PublicType = u32;
+                fn public_method() pub(super) fn public_method()
+            "#]],
         );
     }
 
     #[test]
     fn completes_enum_associated_method() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// An enum
-                enum S {};
-
-                impl S {
-                    /// An associated method
-                    fn m() { }
-                }
-
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 100..100,
-                delete: 100..100,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "An associated method",
-                ),
-            },
-        ]
-        "###
+        check(
+            r#"
+enum E {};
+impl E { fn m() { } }
+
+fn foo() { let _ = E::<|> }
+        "#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
         );
     }
 
     #[test]
     fn completes_union_associated_method() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                /// A union
-                union U {};
-
-                impl U {
-                    /// An associated method
-                    fn m() { }
-                }
-
-                fn foo() { let _ = U::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 101..101,
-                delete: 101..101,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "An associated method",
-                ),
-            },
-        ]
-        "###
+        check(
+            r#"
+union U {};
+impl U { fn m() { } }
+
+fn foo() { let _ = U::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
         );
     }
 
     #[test]
     fn completes_use_paths_across_crates() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                use foo::<|>;
-
-                //- /foo/lib.rs
-                pub mod bar {
-                    pub struct S;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "bar",
-                source_range: 9..9,
-                delete: 9..9,
-                insert: "bar",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /main.rs
+use foo::<|>;
+
+//- /foo/lib.rs
+pub mod bar { pub struct S; }
+"#,
+            expect![[r#"
+                md bar
+            "#]],
         );
     }
 
     #[test]
     fn completes_trait_associated_method_1() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                trait Trait {
-                  /// A trait method
-                  fn m();
-                }
+        check(
+            r#"
+trait Trait { fn m(); }
 
-                fn foo() { let _ = Trait::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 73..73,
-                delete: 73..73,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "A trait method",
-                ),
-            },
-        ]
-        "###
+fn foo() { let _ = Trait::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
         );
     }
 
     #[test]
     fn completes_trait_associated_method_2() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                trait Trait {
-                  /// A trait method
-                  fn m();
-                }
+        check(
+            r#"
+trait Trait { fn m(); }
+
+struct S;
+impl Trait for S {}
 
-                struct S;
-                impl Trait for S {}
-
-                fn foo() { let _ = S::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 99..99,
-                delete: 99..99,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "A trait method",
-                ),
-            },
-        ]
-        "###
+fn foo() { let _ = S::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
         );
     }
 
     #[test]
     fn completes_trait_associated_method_3() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                trait Trait {
-                  /// A trait method
-                  fn m();
-                }
+        check(
+            r#"
+trait Trait { fn m(); }
 
-                struct S;
-                impl Trait for S {}
-
-                fn foo() { let _ = <S as Trait>::<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m()",
-                source_range: 110..110,
-                delete: 110..110,
-                insert: "m()$0",
-                kind: Function,
-                lookup: "m",
-                detail: "fn m()",
-                documentation: Documentation(
-                    "A trait method",
-                ),
-            },
-        ]
-        "###
+struct S;
+impl Trait for S {}
+
+fn foo() { let _ = <S as Trait>::<|> }
+"#,
+            expect![[r#"
+                fn m() fn m()
+            "#]],
         );
     }
 
     #[test]
     fn completes_ty_param_assoc_ty() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                trait Super {
-                    type Ty;
-                    const CONST: u8;
-                    fn func() {}
-                    fn method(&self) {}
-                }
+        check(
+            r#"
+trait Super {
+    type Ty;
+    const CONST: u8;
+    fn func() {}
+    fn method(&self) {}
+}
 
-                trait Sub: Super {
-                    type SubTy;
-                    const C2: ();
-                    fn subfunc() {}
-                    fn submethod(&self) {}
-                }
+trait Sub: Super {
+    type SubTy;
+    const C2: ();
+    fn subfunc() {}
+    fn submethod(&self) {}
+}
 
-                fn foo<T: Sub>() {
-                    T::<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "C2",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "C2",
-                kind: Const,
-                detail: "const C2: ();",
-            },
-            CompletionItem {
-                label: "CONST",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "CONST",
-                kind: Const,
-                detail: "const CONST: u8;",
-            },
-            CompletionItem {
-                label: "SubTy",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "SubTy",
-                kind: TypeAlias,
-                detail: "type SubTy;",
-            },
-            CompletionItem {
-                label: "Ty",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "Ty",
-                kind: TypeAlias,
-                detail: "type Ty;",
-            },
-            CompletionItem {
-                label: "func()",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "func()$0",
-                kind: Function,
-                lookup: "func",
-                detail: "fn func()",
-            },
-            CompletionItem {
-                label: "method()",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "method()$0",
-                kind: Method,
-                lookup: "method",
-                detail: "fn method(&self)",
-            },
-            CompletionItem {
-                label: "subfunc()",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "subfunc()$0",
-                kind: Function,
-                lookup: "subfunc",
-                detail: "fn subfunc()",
-            },
-            CompletionItem {
-                label: "submethod()",
-                source_range: 219..219,
-                delete: 219..219,
-                insert: "submethod()$0",
-                kind: Method,
-                lookup: "submethod",
-                detail: "fn submethod(&self)",
-            },
-        ]
-        "###
+fn foo<T: Sub>() { T::<|> }
+"#,
+            expect![[r#"
+                ct C2          const C2: ();
+                ct CONST       const CONST: u8;
+                ta SubTy       type SubTy;
+                ta Ty          type Ty;
+                fn func()      fn func()
+                me method()    fn method(&self)
+                fn subfunc()   fn subfunc()
+                me submethod() fn submethod(&self)
+            "#]],
         );
     }
 
     #[test]
     fn completes_self_param_assoc_ty() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                trait Super {
-                    type Ty;
-                    const CONST: u8 = 0;
-                    fn func() {}
-                    fn method(&self) {}
-                }
+        check(
+            r#"
+trait Super {
+    type Ty;
+    const CONST: u8 = 0;
+    fn func() {}
+    fn method(&self) {}
+}
 
-                trait Sub: Super {
-                    type SubTy;
-                    const C2: () = ();
-                    fn subfunc() {}
-                    fn submethod(&self) {}
-                }
+trait Sub: Super {
+    type SubTy;
+    const C2: () = ();
+    fn subfunc() {}
+    fn submethod(&self) {}
+}
 
-                struct Wrap<T>(T);
-                impl<T> Super for Wrap<T> {}
-                impl<T> Sub for Wrap<T> {
-                    fn subfunc() {
-                        // Should be able to assume `Self: Sub + Super`
-                        Self::<|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "C2",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "C2",
-                kind: Const,
-                detail: "const C2: () = ();",
-            },
-            CompletionItem {
-                label: "CONST",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "CONST",
-                kind: Const,
-                detail: "const CONST: u8 = 0;",
-            },
-            CompletionItem {
-                label: "SubTy",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "SubTy",
-                kind: TypeAlias,
-                detail: "type SubTy;",
-            },
-            CompletionItem {
-                label: "Ty",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "Ty",
-                kind: TypeAlias,
-                detail: "type Ty;",
-            },
-            CompletionItem {
-                label: "func()",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "func()$0",
-                kind: Function,
-                lookup: "func",
-                detail: "fn func()",
-            },
-            CompletionItem {
-                label: "method()",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "method()$0",
-                kind: Method,
-                lookup: "method",
-                detail: "fn method(&self)",
-            },
-            CompletionItem {
-                label: "subfunc()",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "subfunc()$0",
-                kind: Function,
-                lookup: "subfunc",
-                detail: "fn subfunc()",
-            },
-            CompletionItem {
-                label: "submethod()",
-                source_range: 365..365,
-                delete: 365..365,
-                insert: "submethod()$0",
-                kind: Method,
-                lookup: "submethod",
-                detail: "fn submethod(&self)",
-            },
-        ]
-        "###
+struct Wrap<T>(T);
+impl<T> Super for Wrap<T> {}
+impl<T> Sub for Wrap<T> {
+    fn subfunc() {
+        // Should be able to assume `Self: Sub + Super`
+        Self::<|>
+    }
+}
+"#,
+            expect![[r#"
+                ct C2          const C2: () = ();
+                ct CONST       const CONST: u8 = 0;
+                ta SubTy       type SubTy;
+                ta Ty          type Ty;
+                fn func()      fn func()
+                me method()    fn method(&self)
+                fn subfunc()   fn subfunc()
+                me submethod() fn submethod(&self)
+            "#]],
         );
     }
 
     #[test]
     fn completes_type_alias() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                struct S;
-                impl S { fn foo() {} }
-                type T = S;
-                impl T { fn bar() {} }
-
-                fn main() {
-                    T::<|>;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "bar()",
-                source_range: 185..185,
-                delete: 185..185,
-                insert: "bar()$0",
-                kind: Function,
-                lookup: "bar",
-                detail: "fn bar()",
-            },
-            CompletionItem {
-                label: "foo()",
-                source_range: 185..185,
-                delete: 185..185,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct S;
+impl S { fn foo() {} }
+type T = S;
+impl T { fn bar() {} }
+
+fn main() { T::<|>; }
+"#,
+            expect![[r#"
+                fn bar() fn bar()
+                fn foo() fn foo()
+            "#]],
         );
     }
 
     #[test]
     fn completes_qualified_macros() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                #[macro_export]
-                macro_rules! foo {
-                    () => {}
-                }
+        check(
+            r#"
+#[macro_export]
+macro_rules! foo { () => {} }
+
+fn main() { let _ = crate::<|> }
+        "#,
+            expect![[r##"
+                ma foo!(…) #[macro_export]
+                macro_rules! foo
+                fn main()  fn main()
+            "##]],
+        );
+    }
 
-                fn main() {
-                    let _ = crate::<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 179..179,
-                delete: 179..179,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "#[macro_export]\nmacro_rules! foo",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 179..179,
-                delete: 179..179,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+    #[test]
+    fn test_super_super_completion() {
+        check(
+            r#"
+mod a {
+    const A: usize = 0;
+    mod b {
+        const B: usize = 0;
+        mod c { use super::super::<|> }
+    }
+}
+"#,
+            expect![[r#"
+                ct A
+                md b
+            "#]],
         );
     }
 
     #[test]
     fn completes_reexported_items_under_correct_name() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn foo() {
-                    self::m::<|>
-                }
+        check(
+            r#"
+fn foo() { self::m::<|> }
 
-                mod m {
-                    pub use super::p::wrong_fn as right_fn;
-                    pub use super::p::WRONG_CONST as RIGHT_CONST;
-                    pub use super::p::WrongType as RightType;
-                }
-                mod p {
-                    fn wrong_fn() {}
-                    const WRONG_CONST: u32 = 1;
-                    struct WrongType {};
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "RIGHT_CONST",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "RIGHT_CONST",
-                kind: Const,
-            },
-            CompletionItem {
-                label: "RightType",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "RightType",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "right_fn()",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "right_fn()$0",
-                kind: Function,
-                lookup: "right_fn",
-                detail: "fn wrong_fn()",
-            },
-        ]
-        "###
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
+            expect![[r#"
+                ct RIGHT_CONST
+                st RightType
+                fn right_fn()  fn wrong_fn()
+            "#]],
+        );
+
+        check_edit(
+            "RightType",
+            r#"
+fn foo() { self::m::<|> }
+
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
+            r#"
+fn foo() { self::m::RightType }
+
+mod m {
+    pub use super::p::wrong_fn as right_fn;
+    pub use super::p::WRONG_CONST as RIGHT_CONST;
+    pub use super::p::WrongType as RightType;
+}
+mod p {
+    fn wrong_fn() {}
+    const WRONG_CONST: u32 = 1;
+    struct WrongType {};
+}
+"#,
         );
     }
 
     #[test]
     fn completes_in_simple_macro_call() {
-        let completions = do_reference_completion(
+        check(
             r#"
-                macro_rules! m { ($e:expr) => { $e } }
-                fn main() { m!(self::f<|>); }
-                fn foo() {}
-            "#,
+macro_rules! m { ($e:expr) => { $e } }
+fn main() { m!(self::f<|>); }
+fn foo() {}
+"#,
+            expect![[r#"
+                fn foo()  fn foo()
+                fn main() fn main()
+            "#]],
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "foo()",
-                source_range: 93..94,
-                delete: 93..94,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 93..94,
-                delete: 93..94,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn function_mod_share_name() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                fn foo() {
-                    self::m::<|>
-                }
+        check(
+            r#"
+fn foo() { self::m::<|> }
 
-                mod m {
-                    pub mod z {}
-                    pub fn z() {}
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "z",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "z",
-                kind: Module,
-            },
-            CompletionItem {
-                label: "z()",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "z()$0",
-                kind: Function,
-                lookup: "z",
-                detail: "pub fn z()",
-            },
-        ]
-        "###
+mod m {
+    pub mod z {}
+    pub fn z() {}
+}
+"#,
+            expect![[r#"
+                md z
+                fn z() pub fn z()
+            "#]],
         );
     }
 
     #[test]
     fn completes_hashmap_new() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct RandomState;
-                struct HashMap<K, V, S = RandomState> {}
-
-                impl<K, V> HashMap<K, V, RandomState> {
-                    pub fn new() -> HashMap<K, V, RandomState> { }
-                }
-                fn foo() {
-                    HashMap::<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "new()",
-                source_range: 292..292,
-                delete: 292..292,
-                insert: "new()$0",
-                kind: Function,
-                lookup: "new",
-                detail: "pub fn new() -> HashMap<K, V, RandomState>",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct RandomState;
+struct HashMap<K, V, S = RandomState> {}
+
+impl<K, V> HashMap<K, V, RandomState> {
+    pub fn new() -> HashMap<K, V, RandomState> { }
+}
+fn foo() {
+    HashMap::<|>
+}
+"#,
+            expect![[r#"
+                fn new() pub fn new() -> HashMap<K, V, RandomState>
+            "#]],
         );
     }
 
     #[test]
     fn dont_complete_attr() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                mod foo { pub struct Foo; }
-                #[foo::<|>]
-                fn f() {}
-                "
-            ),
-            @r###"[]"###
-        )
+        check(
+            r#"
+mod foo { pub struct Foo; }
+#[foo::<|>]
+fn f() {}
+"#,
+            expect![[""]],
+        );
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_record.rs b/crates/ra_ide/src/completion/complete_record.rs
index b7ab654c5..74b94594d 100644
--- a/crates/ra_ide/src/completion/complete_record.rs
+++ b/crates/ra_ide/src/completion/complete_record.rs
@@ -18,389 +18,209 @@ pub(super) fn complete_record(acc: &mut Completions, ctx: &CompletionContext) ->
 
 #[cfg(test)]
 mod tests {
-    mod record_pat_tests {
-        use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-        use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    use crate::completion::{test_utils::completion_list, CompletionKind};
 
-        fn complete(code: &str) -> Vec<CompletionItem> {
-            do_completion(code, CompletionKind::Reference)
-        }
-
-        #[test]
-        fn test_record_pattern_field() {
-            let completions = complete(
-                r"
-            struct S { foo: u32 }
-
-            fn process(f: S) {
-                match f {
-                    S { f<|>: 92 } => (),
-                }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "foo",
-                source_range: 117..118,
-                delete: 117..118,
-                insert: "foo",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
-
-        #[test]
-        fn test_record_pattern_enum_variant() {
-            let completions = complete(
-                r"
-            enum E {
-                S { foo: u32, bar: () }
-            }
-
-            fn process(e: E) {
-                match e {
-                    E::S { <|> } => (),
-                }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "bar",
-                source_range: 161..161,
-                delete: 161..161,
-                insert: "bar",
-                kind: Field,
-                detail: "()",
-            },
-            CompletionItem {
-                label: "foo",
-                source_range: 161..161,
-                delete: 161..161,
-                insert: "foo",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual);
+    }
 
-        #[test]
-        fn test_record_pattern_field_in_simple_macro() {
-            let completions = complete(
-                r"
-            macro_rules! m { ($e:expr) => { $e } }
-            struct S { foo: u32 }
+    #[test]
+    fn test_record_pattern_field() {
+        check(
+            r#"
+struct S { foo: u32 }
 
-            fn process(f: S) {
-                m!(match f {
-                    S { f<|>: 92 } => (),
-                })
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "foo",
-                source_range: 171..172,
-                delete: 171..172,
-                insert: "foo",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn process(f: S) {
+    match f {
+        S { f<|>: 92 } => (),
+    }
+}
+"#,
+            expect![[r#"
+                fd foo u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn only_missing_fields_are_completed_in_destruct_pats() {
-            let completions = complete(
-                r"
-            struct S {
-                foo1: u32,
-                foo2: u32,
-                bar: u32,
-                baz: u32,
-            }
+    #[test]
+    fn test_record_pattern_enum_variant() {
+        check(
+            r#"
+enum E { S { foo: u32, bar: () } }
 
-            fn main() {
-                let s = S {
-                    foo1: 1,
-                    foo2: 2,
-                    bar: 3,
-                    baz: 4,
-                };
-                if let S { foo1, foo2: a, <|> } = s {}
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "bar",
-                source_range: 372..372,
-                delete: 372..372,
-                insert: "bar",
-                kind: Field,
-                detail: "u32",
-            },
-            CompletionItem {
-                label: "baz",
-                source_range: 372..372,
-                delete: 372..372,
-                insert: "baz",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn process(e: E) {
+    match e {
+        E::S { <|> } => (),
+    }
+}
+"#,
+            expect![[r#"
+                fd bar ()
+                fd foo u32
+            "#]],
+        );
     }
 
-    mod record_lit_tests {
-        use insta::assert_debug_snapshot;
-
-        use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    #[test]
+    fn test_record_pattern_field_in_simple_macro() {
+        check(
+            r"
+macro_rules! m { ($e:expr) => { $e } }
+struct S { foo: u32 }
+
+fn process(f: S) {
+    m!(match f {
+        S { f<|>: 92 } => (),
+    })
+}
+",
+            expect![[r#"
+                fd foo u32
+            "#]],
+        );
+    }
 
-        fn complete(code: &str) -> Vec<CompletionItem> {
-            do_completion(code, CompletionKind::Reference)
-        }
+    #[test]
+    fn only_missing_fields_are_completed_in_destruct_pats() {
+        check(
+            r#"
+struct S {
+    foo1: u32, foo2: u32,
+    bar: u32, baz: u32,
+}
 
-        #[test]
-        fn test_record_literal_deprecated_field() {
-            let completions = complete(
-                r"
-            struct A {
-                #[deprecated]
-                the_field: u32,
-            }
-            fn foo() {
-               A { the<|> }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 142..145,
-                delete: 142..145,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-                deprecated: true,
-            },
-        ]
-        "###);
-        }
+fn main() {
+    let s = S {
+        foo1: 1, foo2: 2,
+        bar: 3, baz: 4,
+    };
+    if let S { foo1, foo2: a, <|> } = s {}
+}
+"#,
+            expect![[r#"
+                fd bar u32
+                fd baz u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn test_record_literal_field() {
-            let completions = complete(
-                r"
-            struct A { the_field: u32 }
-            fn foo() {
-               A { the<|> }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 83..86,
-                delete: 83..86,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+    #[test]
+    fn test_record_literal_field() {
+        check(
+            r#"
+struct A { the_field: u32 }
+fn foo() {
+   A { the<|> }
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn test_record_literal_enum_variant() {
-            let completions = complete(
-                r"
-            enum E {
-                A { a: u32 }
-            }
-            fn foo() {
-                let _ = E::A { <|> }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "a",
-                source_range: 119..119,
-                delete: 119..119,
-                insert: "a",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+    #[test]
+    fn test_record_literal_enum_variant() {
+        check(
+            r#"
+enum E { A { a: u32 } }
+fn foo() {
+    let _ = E::A { <|> }
+}
+"#,
+            expect![[r#"
+                fd a u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn test_record_literal_two_structs() {
-            let completions = complete(
-                r"
-            struct A { a: u32 }
-            struct B { b: u32 }
+    #[test]
+    fn test_record_literal_two_structs() {
+        check(
+            r#"
+struct A { a: u32 }
+struct B { b: u32 }
 
-            fn foo() {
-               let _: A = B { <|> }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "b",
-                source_range: 119..119,
-                delete: 119..119,
-                insert: "b",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn foo() {
+   let _: A = B { <|> }
+}
+"#,
+            expect![[r#"
+                fd b u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn test_record_literal_generic_struct() {
-            let completions = complete(
-                r"
-            struct A<T> { a: T }
+    #[test]
+    fn test_record_literal_generic_struct() {
+        check(
+            r#"
+struct A<T> { a: T }
 
-            fn foo() {
-               let _: A<u32> = A { <|> }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "a",
-                source_range: 93..93,
-                delete: 93..93,
-                insert: "a",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn foo() {
+   let _: A<u32> = A { <|> }
+}
+"#,
+            expect![[r#"
+                fd a u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn test_record_literal_field_in_simple_macro() {
-            let completions = complete(
-                r"
-            macro_rules! m { ($e:expr) => { $e } }
-            struct A { the_field: u32 }
-            fn foo() {
-               m!(A { the<|> })
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "the_field",
-                source_range: 137..140,
-                delete: 137..140,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+    #[test]
+    fn test_record_literal_field_in_simple_macro() {
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+struct A { the_field: u32 }
+fn foo() {
+   m!(A { the<|> })
+}
+"#,
+            expect![[r#"
+                fd the_field u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn only_missing_fields_are_completed() {
-            let completions = complete(
-                r"
-            struct S {
-                foo1: u32,
-                foo2: u32,
-                bar: u32,
-                baz: u32,
-            }
+    #[test]
+    fn only_missing_fields_are_completed() {
+        check(
+            r#"
+struct S {
+    foo1: u32, foo2: u32,
+    bar: u32, baz: u32,
+}
 
-            fn main() {
-                let foo1 = 1;
-                let s = S {
-                    foo1,
-                    foo2: 5,
-                    <|>
-                }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "bar",
-                source_range: 302..302,
-                delete: 302..302,
-                insert: "bar",
-                kind: Field,
-                detail: "u32",
-            },
-            CompletionItem {
-                label: "baz",
-                source_range: 302..302,
-                delete: 302..302,
-                insert: "baz",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn main() {
+    let foo1 = 1;
+    let s = S { foo1, foo2: 5, <|> }
+}
+"#,
+            expect![[r#"
+                fd bar u32
+                fd baz u32
+            "#]],
+        );
+    }
 
-        #[test]
-        fn completes_functional_update() {
-            let completions = complete(
-                r"
-            struct S {
-                foo1: u32,
-                foo2: u32,
-            }
+    #[test]
+    fn completes_functional_update() {
+        check(
+            r#"
+struct S { foo1: u32, foo2: u32 }
 
-            fn main() {
-                let foo1 = 1;
-                let s = S {
-                    foo1,
-                    <|>
-                    .. loop {}
-                }
-            }
-            ",
-            );
-            assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "foo2",
-                source_range: 221..221,
-                delete: 221..221,
-                insert: "foo2",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###);
-        }
+fn main() {
+    let foo1 = 1;
+    let s = S { foo1, <|> .. loop {} }
+}
+"#,
+            expect![[r#"
+                fd foo2 u32
+            "#]],
+        );
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_snippet.rs b/crates/ra_ide/src/completion/complete_snippet.rs
index 0568d9ccf..28d8f7876 100644
--- a/crates/ra_ide/src/completion/complete_snippet.rs
+++ b/crates/ra_ide/src/completion/complete_snippet.rs
@@ -70,95 +70,47 @@ fn ${1:feature}() {
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    fn do_snippet_completion(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Snippet)
+    use crate::completion::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Snippet);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn completes_snippets_in_expressions() {
-        assert_debug_snapshot!(
-                    do_snippet_completion(r"fn foo(x: i32) { <|> }"),
-        @r###"
-        [
-            CompletionItem {
-                label: "pd",
-                source_range: 17..17,
-                delete: 17..17,
-                insert: "eprintln!(\"$0 = {:?}\", $0);",
-                kind: Snippet,
-            },
-            CompletionItem {
-                label: "ppd",
-                source_range: 17..17,
-                delete: 17..17,
-                insert: "eprintln!(\"$0 = {:#?}\", $0);",
-                kind: Snippet,
-            },
-        ]
-        "###
-                );
+        check(
+            r#"fn foo(x: i32) { <|> }"#,
+            expect![[r#"
+                sn pd
+                sn ppd
+            "#]],
+        );
     }
 
     #[test]
     fn should_not_complete_snippets_in_path() {
-        assert_debug_snapshot!(
-                    do_snippet_completion(r"fn foo(x: i32) { ::foo<|> }"),
-        @"[]"
-                );
-        assert_debug_snapshot!(
-                    do_snippet_completion(r"fn foo(x: i32) { ::<|> }"),
-        @"[]"
-                );
+        check(r#"fn foo(x: i32) { ::foo<|> }"#, expect![[""]]);
+        check(r#"fn foo(x: i32) { ::<|> }"#, expect![[""]]);
     }
 
     #[test]
     fn completes_snippets_in_items() {
-        assert_debug_snapshot!(
-            do_snippet_completion(
-                r"
-                #[cfg(test)]
-                mod tests {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Test function",
-                source_range: 78..78,
-                delete: 78..78,
-                insert: "#[test]\nfn ${1:feature}() {\n    $0\n}",
-                kind: Snippet,
-                lookup: "tfn",
-            },
-            CompletionItem {
-                label: "Test module",
-                source_range: 78..78,
-                delete: 78..78,
-                insert: "#[cfg(test)]\nmod tests {\n    use super::*;\n\n    #[test]\n    fn ${1:test_name}() {\n        $0\n    }\n}",
-                kind: Snippet,
-                lookup: "tmod",
-            },
-            CompletionItem {
-                label: "macro_rules",
-                source_range: 78..78,
-                delete: 78..78,
-                insert: "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}",
-                kind: Snippet,
-            },
-            CompletionItem {
-                label: "pub(crate)",
-                source_range: 78..78,
-                delete: 78..78,
-                insert: "pub(crate) $0",
-                kind: Snippet,
-            },
-        ]
-        "###
-        );
+        check(
+            r#"
+#[cfg(test)]
+mod tests {
+    <|>
+}
+"#,
+            expect![[r#"
+                sn Test function
+                sn Test module
+                sn macro_rules
+                sn pub(crate)
+            "#]],
+        )
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index 21c9316e6..a610fd6d1 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -227,330 +227,264 @@ fn make_const_compl_syntax(const_: &ast::ConstDef) -> String {
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
 
-    fn complete(code: &str) -> Vec<CompletionItem> {
-        do_completion(code, CompletionKind::Magic)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Magic);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn name_ref_function_type_const() {
-        let completions = complete(
-            r"
-            trait Test {
-                type TestType;
-                const TEST_CONST: u16;
-                fn test();
-            }
-
-            struct T1;
+        check(
+            r#"
+trait Test {
+    type TestType;
+    const TEST_CONST: u16;
+    fn test();
+}
+struct T;
 
-            impl Test for T1 {
-                t<|>
-            }
-            ",
+impl Test for T {
+    t<|>
+}
+"#,
+            expect![["
+ct const TEST_CONST: u16 = \n\
+fn fn test()
+ta type TestType = \n\
+            "]],
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "const TEST_CONST: u16 = ",
-                source_range: 209..210,
-                delete: 209..210,
-                insert: "const TEST_CONST: u16 = ",
-                kind: Const,
-                lookup: "TEST_CONST",
-            },
-            CompletionItem {
-                label: "fn test()",
-                source_range: 209..210,
-                delete: 209..210,
-                insert: "fn test() {\n    $0\n}",
-                kind: Function,
-                lookup: "test",
-            },
-            CompletionItem {
-                label: "type TestType = ",
-                source_range: 209..210,
-                delete: 209..210,
-                insert: "type TestType = ",
-                kind: TypeAlias,
-                lookup: "TestType",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn no_nested_fn_completions() {
-        let completions = complete(
+        check(
             r"
-            trait Test {
-                fn test();
-                fn test2();
-            }
-
-            struct T1;
+trait Test {
+    fn test();
+    fn test2();
+}
+struct T;
 
-            impl Test for T1 {
-                fn test() {
-                    t<|>
-                }
-            }
-            ",
+impl Test for T {
+    fn test() {
+        t<|>
+    }
+}
+",
+            expect![[""]],
         );
-        assert_debug_snapshot!(completions, @r###"[]"###);
     }
 
     #[test]
     fn name_ref_single_function() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn test();
-            }
+        check_edit(
+            "test",
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
 
-            struct T1;
+impl Test for T {
+    t<|>
+}
+"#,
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
 
-            impl Test for T1 {
-                t<|>
-            }
-            ",
+impl Test for T {
+    fn test() {
+    $0
+}
+}
+"#,
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "fn test()",
-                source_range: 139..140,
-                delete: 139..140,
-                insert: "fn test() {\n    $0\n}",
-                kind: Function,
-                lookup: "test",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn single_function() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn foo();
-            }
+        check_edit(
+            "test",
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
 
-            struct T1;
+impl Test for T {
+    fn t<|>
+}
+"#,
+            r#"
+trait Test {
+    fn test();
+}
+struct T;
 
-            impl Test for T1 {
-                fn f<|>
-            }
-            ",
+impl Test for T {
+    fn test() {
+    $0
+}
+}
+"#,
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "fn foo()",
-                source_range: 141..142,
-                delete: 138..142,
-                insert: "fn foo() {\n    $0\n}",
-                kind: Function,
-                lookup: "foo",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn hide_implemented_fn() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn foo();
-                fn foo_bar();
-            }
-
-            struct T1;
-
-            impl Test for T1 {
-                fn foo() {}
-
-                fn f<|>
-            }
-            ",
-        );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "fn foo_bar()",
-                source_range: 200..201,
-                delete: 197..201,
-                insert: "fn foo_bar() {\n    $0\n}",
-                kind: Function,
-                lookup: "foo_bar",
-            },
-        ]
-        "###);
-    }
-
-    #[test]
-    fn completes_only_on_top_level() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn foo();
-
-                fn foo_bar();
-            }
-
-            struct T1;
+        check(
+            r#"
+trait Test {
+    fn foo();
+    fn foo_bar();
+}
+struct T;
 
-            impl Test for T1 {
-                fn foo() {
-                    <|>
-                }
-            }
-            ",
+impl Test for T {
+    fn foo() {}
+    fn f<|>
+}
+"#,
+            expect![[r#"
+                fn fn foo_bar()
+            "#]],
         );
-        assert_debug_snapshot!(completions, @r###"[]"###);
     }
 
     #[test]
     fn generic_fn() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn foo<T>();
-            }
+        check_edit(
+            "foo",
+            r#"
+trait Test {
+    fn foo<T>();
+}
+struct T;
 
-            struct T1;
+impl Test for T {
+    fn f<|>
+}
+"#,
+            r#"
+trait Test {
+    fn foo<T>();
+}
+struct T;
 
-            impl Test for T1 {
-                fn f<|>
-            }
-            ",
+impl Test for T {
+    fn foo<T>() {
+    $0
+}
+}
+"#,
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "fn foo()",
-                source_range: 144..145,
-                delete: 141..145,
-                insert: "fn foo<T>() {\n    $0\n}",
-                kind: Function,
-                lookup: "foo",
-            },
-        ]
-        "###);
-    }
-
-    #[test]
-    fn generic_constrait_fn() {
-        let completions = complete(
-            r"
-            trait Test {
-                fn foo<T>() where T: Into<String>;
-            }
+        check_edit(
+            "foo",
+            r#"
+trait Test {
+    fn foo<T>() where T: Into<String>;
+}
+struct T;
 
-            struct T1;
+impl Test for T {
+    fn f<|>
+}
+"#,
+            r#"
+trait Test {
+    fn foo<T>() where T: Into<String>;
+}
+struct T;
 
-            impl Test for T1 {
-                fn f<|>
-            }
-            ",
+impl Test for T {
+    fn foo<T>()
+where T: Into<String> {
+    $0
+}
+}
+"#,
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "fn foo()",
-                source_range: 166..167,
-                delete: 163..167,
-                insert: "fn foo<T>()\nwhere T: Into<String> {\n    $0\n}",
-                kind: Function,
-                lookup: "foo",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn associated_type() {
-        let completions = complete(
-            r"
-            trait Test {
-                type SomeType;
-            }
+        check_edit(
+            "SomeType",
+            r#"
+trait Test {
+    type SomeType;
+}
 
-            impl Test for () {
-                type S<|>
-            }
-            ",
+impl Test for () {
+    type S<|>
+}
+"#,
+            "
+trait Test {
+    type SomeType;
+}
+
+impl Test for () {
+    type SomeType = \n\
+}
+",
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "type SomeType = ",
-                source_range: 124..125,
-                delete: 119..125,
-                insert: "type SomeType = ",
-                kind: TypeAlias,
-                lookup: "SomeType",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn associated_const() {
-        let completions = complete(
-            r"
-            trait Test {
-                const SOME_CONST: u16;
-            }
+        check_edit(
+            "SOME_CONST",
+            r#"
+trait Test {
+    const SOME_CONST: u16;
+}
 
-            impl Test for () {
-                const S<|>
-            }
-            ",
+impl Test for () {
+    const S<|>
+}
+"#,
+            "
+trait Test {
+    const SOME_CONST: u16;
+}
+
+impl Test for () {
+    const SOME_CONST: u16 = \n\
+}
+",
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "const SOME_CONST: u16 = ",
-                source_range: 133..134,
-                delete: 127..134,
-                insert: "const SOME_CONST: u16 = ",
-                kind: Const,
-                lookup: "SOME_CONST",
-            },
-        ]
-        "###);
-    }
 
-    #[test]
-    fn associated_const_with_default() {
-        let completions = complete(
-            r"
-            trait Test {
-                const SOME_CONST: u16 = 42;
-            }
+        check_edit(
+            "SOME_CONST",
+            r#"
+trait Test {
+    const SOME_CONST: u16 = 92;
+}
 
-            impl Test for () {
-                const S<|>
-            }
-            ",
+impl Test for () {
+    const S<|>
+}
+"#,
+            "
+trait Test {
+    const SOME_CONST: u16 = 92;
+}
+
+impl Test for () {
+    const SOME_CONST: u16 = \n\
+}
+",
         );
-        assert_debug_snapshot!(completions, @r###"
-        [
-            CompletionItem {
-                label: "const SOME_CONST: u16 = ",
-                source_range: 138..139,
-                delete: 132..139,
-                insert: "const SOME_CONST: u16 = ",
-                kind: Const,
-                lookup: "SOME_CONST",
-            },
-        ]
-        "###);
     }
 }
diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index 68032c37e..bd9551f35 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -1,11 +1,10 @@
 //! Completion of names from the current scope, e.g. locals and imported items.
 
-use hir::ScopeDef;
+use hir::{Adt, ModuleDef, ScopeDef, Type};
+use ra_syntax::AstNode;
 use test_utils::mark;
 
 use crate::completion::{CompletionContext, Completions};
-use hir::{Adt, ModuleDef, Type};
-use ra_syntax::AstNode;
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
     if !(ctx.is_trivial_path || ctx.is_pat_binding_or_const) {
@@ -26,7 +25,7 @@ pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         return;
     }
 
-    ctx.scope().process_all_names(&mut |name, res| {
+    ctx.scope.process_all_names(&mut |name, res| {
         if ctx.use_item_syntax.is_some() {
             if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
                 if name_ref.syntax().text() == name.to_string().as_str() {
@@ -43,7 +42,7 @@ fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &T
     if let Some(Adt::Enum(enum_data)) = ty.as_adt() {
         let variants = enum_data.variants(ctx.db);
 
-        let module = if let Some(module) = ctx.scope().module() {
+        let module = if let Some(module) = ctx.scope.module() {
             // Compute path from the completion site if available.
             module
         } else {
@@ -65,1361 +64,595 @@ fn complete_enum_variants(acc: &mut Completions, ctx: &CompletionContext, ty: &T
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
     use test_utils::mark;
 
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+    use crate::completion::{
+        test_utils::{check_edit, completion_list},
+        CompletionKind,
+    };
 
-    fn do_reference_completion(ra_fixture: &str) -> Vec<CompletionItem> {
-        do_completion(ra_fixture, CompletionKind::Reference)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Reference);
+        expect.assert_eq(&actual)
     }
 
     #[test]
     fn self_fulfilling_completion() {
         mark::check!(self_fulfilling_completion);
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r#"
-                use foo<|>
-                use std::collections;
-                "#,
-            ),
-            @r###"
-            [
-                CompletionItem {
-                    label: "collections",
-                    source_range: 21..24,
-                    delete: 21..24,
-                    insert: "collections",
-                },
-            ]
-            "###
+        check(
+            r#"
+use foo<|>
+use std::collections;
+"#,
+            expect![[r#"
+                ?? collections
+            "#]],
         );
     }
 
     #[test]
     fn bind_pat_and_path_ignore_at() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Enum {
-                    A,
-                    B,
-                }
-                fn quux(x: Option<Enum>) {
-                    match x {
-                        None => (),
-                        Some(en<|> @ Enum::A) => (),
-                    }
-                }
-                "
-            ),
-            @"[]"
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(en<|> @ Enum::A) => (),
+    }
+}
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
     fn bind_pat_and_path_ignore_ref() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Enum {
-                    A,
-                    B,
-                }
-                fn quux(x: Option<Enum>) {
-                    match x {
-                        None => (),
-                        Some(ref en<|>) => (),
-                    }
-                }
-                "
-            ),
-            @r###"[]"###
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(ref en<|>) => (),
+    }
+}
+"#,
+            expect![[""]],
         );
     }
 
     #[test]
     fn bind_pat_and_path() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Enum {
-                    A,
-                    B,
-                }
-                fn quux(x: Option<Enum>) {
-                    match x {
-                        None => (),
-                        Some(En<|>) => (),
-                    }
-                }
-                "
-            ),
-            @r###"
-            [
-                CompletionItem {
-                    label: "Enum",
-                    source_range: 231..233,
-                    delete: 231..233,
-                    insert: "Enum",
-                    kind: Enum,
-                },
-            ]
-            "###
+        check(
+            r#"
+enum Enum { A, B }
+fn quux(x: Option<Enum>) {
+    match x {
+        None => (),
+        Some(En<|>) => (),
+    }
+}
+"#,
+            expect![[r#"
+                en Enum
+            "#]],
         );
     }
 
     #[test]
     fn completes_bindings_from_let() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn quux(x: i32) {
-                    let y = 92;
-                    1 + <|>;
-                    let z = ();
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "quux(…)",
-                source_range: 91..91,
-                delete: 91..91,
-                insert: "quux(${1:x})$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux(x: i32)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "x",
-                source_range: 91..91,
-                delete: 91..91,
-                insert: "x",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "y",
-                source_range: 91..91,
-                delete: 91..91,
-                insert: "y",
-                kind: Binding,
-                detail: "i32",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn quux(x: i32) {
+    let y = 92;
+    1 + <|>;
+    let z = ();
+}
+"#,
+            expect![[r#"
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
         );
     }
 
     #[test]
     fn completes_bindings_from_if_let() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn quux() {
-                    if let Some(x) = foo() {
-                        let y = 92;
-                    };
-                    if let Some(a) = bar() {
-                        let b = 62;
-                        1 + <|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "a",
-                source_range: 242..242,
-                delete: 242..242,
-                insert: "a",
-                kind: Binding,
-            },
-            CompletionItem {
-                label: "b",
-                source_range: 242..242,
-                delete: 242..242,
-                insert: "b",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "quux()",
-                source_range: 242..242,
-                delete: 242..242,
-                insert: "quux()$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux()",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn quux() {
+    if let Some(x) = foo() {
+        let y = 92;
+    };
+    if let Some(a) = bar() {
+        let b = 62;
+        1 + <|>
+    }
+}
+"#,
+            expect![[r#"
+                bn a
+                bn b      i32
+                fn quux() fn quux()
+            "#]],
         );
     }
 
     #[test]
     fn completes_bindings_from_for() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn quux() {
-                    for x in &[1, 2, 3] {
-                        <|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "quux()",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "quux()$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux()",
-            },
-            CompletionItem {
-                label: "x",
-                source_range: 95..95,
-                delete: 95..95,
-                insert: "x",
-                kind: Binding,
-            },
-        ]
-        "###
+        check(
+            r#"
+fn quux() {
+    for x in &[1, 2, 3] { <|> }
+}
+"#,
+            expect![[r#"
+                fn quux() fn quux()
+                bn x
+            "#]],
         );
     }
 
     #[test]
-    fn completes_bindings_from_for_with_in_prefix() {
-        mark::check!(completes_bindings_from_for_with_in_prefix);
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn test() {
-                    for index in &[1, 2, 3] {
-                        let t = in<|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "index",
-                source_range: 107..107,
-                delete: 107..107,
-                insert: "index",
-                kind: Binding,
-            },
-            CompletionItem {
-                label: "test()",
-                source_range: 107..107,
-                delete: 107..107,
-                insert: "test()$0",
-                kind: Function,
-                lookup: "test",
-                detail: "fn test()",
-            },
-        ]
-        "###
-        );
+    fn completes_if_prefix_is_keyword() {
+        mark::check!(completes_if_prefix_is_keyword);
+        check_edit(
+            "wherewolf",
+            r#"
+fn main() {
+    let wherewolf = 92;
+    drop(where<|>)
+}
+"#,
+            r#"
+fn main() {
+    let wherewolf = 92;
+    drop(wherewolf)
+}
+"#,
+        )
     }
 
     #[test]
     fn completes_generic_params() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn quux<T>() {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "T",
-                source_range: 52..52,
-                delete: 52..52,
-                insert: "T",
-                kind: TypeParam,
-            },
-            CompletionItem {
-                label: "quux()",
-                source_range: 52..52,
-                delete: 52..52,
-                insert: "quux()$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux<T>()",
-            },
-        ]
-        "###
+        check(
+            r#"fn quux<T>() { <|> }"#,
+            expect![[r#"
+                tp T
+                fn quux() fn quux<T>()
+            "#]],
         );
     }
 
     #[test]
     fn completes_generic_params_in_struct() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct X<T> {
-                    x: <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Self",
-                source_range: 54..54,
-                delete: 54..54,
-                insert: "Self",
-                kind: TypeParam,
-            },
-            CompletionItem {
-                label: "T",
-                source_range: 54..54,
-                delete: 54..54,
-                insert: "T",
-                kind: TypeParam,
-            },
-            CompletionItem {
-                label: "X<…>",
-                source_range: 54..54,
-                delete: 54..54,
-                insert: "X<$0>",
-                kind: Struct,
-                lookup: "X",
-            },
-        ]
-        "###
+        check(
+            r#"struct S<T> { x: <|>}"#,
+            expect![[r#"
+                st S<…>
+                tp Self
+                tp T
+            "#]],
         );
     }
 
     #[test]
     fn completes_self_in_enum() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum X {
-                    Y(<|>)
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Self",
-                source_range: 48..48,
-                delete: 48..48,
-                insert: "Self",
-                kind: TypeParam,
-            },
-            CompletionItem {
-                label: "X",
-                source_range: 48..48,
-                delete: 48..48,
-                insert: "X",
-                kind: Enum,
-            },
-        ]
-        "###
+        check(
+            r#"enum X { Y(<|>) }"#,
+            expect![[r#"
+                tp Self
+                en X
+            "#]],
         );
     }
 
     #[test]
     fn completes_module_items() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-            r"
-                struct Foo;
-                enum Baz {}
-                fn quux() {
-                    <|>
-                }
-                "
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "Baz",
-                source_range: 105..105,
-                delete: 105..105,
-                insert: "Baz",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Foo",
-                source_range: 105..105,
-                delete: 105..105,
-                insert: "Foo",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "quux()",
-                source_range: 105..105,
-                delete: 105..105,
-                insert: "quux()$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux()",
-            },
-        ]
-        "###
-            );
+        check(
+            r#"
+struct S;
+enum E {}
+fn quux() { <|> }
+"#,
+            expect![[r#"
+                en E
+                st S
+                fn quux() fn quux()
+            "#]],
+        );
     }
 
     #[test]
     fn completes_extern_prelude() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                //- /lib.rs
-                use <|>;
-
-                //- /other_crate/lib.rs
-                // nothing here
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "other_crate",
-                source_range: 4..4,
-                delete: 4..4,
-                insert: "other_crate",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /lib.rs
+use <|>;
+
+//- /other_crate/lib.rs
+// nothing here
+"#,
+            expect![[r#"
+                md other_crate
+            "#]],
         );
     }
 
     #[test]
     fn completes_module_items_in_nested_modules() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Foo;
-                mod m {
-                    struct Bar;
-                    fn quux() { <|> }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Bar",
-                source_range: 117..117,
-                delete: 117..117,
-                insert: "Bar",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "quux()",
-                source_range: 117..117,
-                delete: 117..117,
-                insert: "quux()$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux()",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct Foo;
+mod m {
+    struct Bar;
+    fn quux() { <|> }
+}
+"#,
+            expect![[r#"
+                st Bar
+                fn quux() fn quux()
+            "#]],
         );
     }
 
     #[test]
     fn completes_return_type() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Foo;
-                fn x() -> <|>
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 55..55,
-                delete: 55..55,
-                insert: "Foo",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "x()",
-                source_range: 55..55,
-                delete: 55..55,
-                insert: "x()$0",
-                kind: Function,
-                lookup: "x",
-                detail: "fn x()",
-            },
-        ]
-        "###
+        check(
+            r#"
+struct Foo;
+fn x() -> <|>
+"#,
+            expect![[r#"
+                st Foo
+                fn x() fn x()
+            "#]],
         );
     }
 
     #[test]
     fn dont_show_both_completions_for_shadowing() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn foo() {
-                    let bar = 92;
-                    {
-                        let bar = 62;
-                        <|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "bar",
-                source_range: 146..146,
-                delete: 146..146,
-                insert: "bar",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "foo()",
-                source_range: 146..146,
-                delete: 146..146,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-        ]
-        "###
+        check(
+            r#"
+fn foo() {
+    let bar = 92;
+    {
+        let bar = 62;
+        drop(<|>)
+    }
+}
+"#,
+            // FIXME: should be only one bar here
+            expect![[r#"
+                bn bar   i32
+                bn bar   i32
+                fn foo() fn foo()
+            "#]],
         );
     }
 
     #[test]
     fn completes_self_in_methods() {
-        assert_debug_snapshot!(
-            do_reference_completion(r"impl S { fn foo(&self) { <|> } }"),
-            @r###"
-        [
-            CompletionItem {
-                label: "Self",
-                source_range: 25..25,
-                delete: 25..25,
-                insert: "Self",
-                kind: TypeParam,
-            },
-            CompletionItem {
-                label: "self",
-                source_range: 25..25,
-                delete: 25..25,
-                insert: "self",
-                kind: Binding,
-                detail: "&{unknown}",
-            },
-        ]
-        "###
+        check(
+            r#"impl S { fn foo(&self) { <|> } }"#,
+            expect![[r#"
+                tp Self
+                bn self &{unknown}
+            "#]],
         );
     }
 
     #[test]
     fn completes_prelude() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                fn foo() { let x: <|> }
-
-                //- /std/lib.rs
-                #[prelude_import]
-                use prelude::*;
-
-                mod prelude {
-                    struct Option;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Option",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "Option",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "foo()",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-            CompletionItem {
-                label: "std",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "std",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /main.rs
+fn foo() { let x: <|> }
+
+//- /std/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct Option; }
+"#,
+            expect![[r#"
+                st Option
+                fn foo()  fn foo()
+                md std
+            "#]],
         );
     }
 
     #[test]
     fn completes_std_prelude_if_core_is_defined() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                fn foo() { let x: <|> }
-
-                //- /core/lib.rs
-                #[prelude_import]
-                use prelude::*;
-
-                mod prelude {
-                    struct Option;
-                }
-
-                //- /std/lib.rs
-                #[prelude_import]
-                use prelude::*;
-
-                mod prelude {
-                    struct String;
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "String",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "String",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "core",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "core",
-                kind: Module,
-            },
-            CompletionItem {
-                label: "foo()",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-            CompletionItem {
-                label: "std",
-                source_range: 18..18,
-                delete: 18..18,
-                insert: "std",
-                kind: Module,
-            },
-        ]
-        "###
+        check(
+            r#"
+//- /main.rs
+fn foo() { let x: <|> }
+
+//- /core/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct Option; }
+
+//- /std/lib.rs
+#[prelude_import]
+use prelude::*;
+
+mod prelude { struct String; }
+"#,
+            expect![[r#"
+                st String
+                md core
+                fn foo()  fn foo()
+                md std
+            "#]],
         );
     }
 
     #[test]
     fn completes_macros_as_value() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                macro_rules! foo {
-                    () => {}
-                }
+        check(
+            r#"
+macro_rules! foo { () => {} }
 
-                #[macro_use]
-                mod m1 {
-                    macro_rules! bar {
-                        () => {}
-                    }
-                }
+#[macro_use]
+mod m1 {
+    macro_rules! bar { () => {} }
+}
 
-                mod m2 {
-                    macro_rules! nope {
-                        () => {}
-                    }
+mod m2 {
+    macro_rules! nope { () => {} }
 
-                    #[macro_export]
-                    macro_rules! baz {
-                        () => {}
-                    }
-                }
+    #[macro_export]
+    macro_rules! baz { () => {} }
+}
 
-                fn main() {
-                    let v = <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "bar!(…)",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "bar!($0)",
-                kind: Macro,
-                detail: "macro_rules! bar",
-            },
-            CompletionItem {
-                label: "baz!(…)",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "baz!($0)",
-                kind: Macro,
-                detail: "#[macro_export]\nmacro_rules! baz",
-            },
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "macro_rules! foo",
-            },
-            CompletionItem {
-                label: "m1",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "m1",
-                kind: Module,
-            },
-            CompletionItem {
-                label: "m2",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "m2",
-                kind: Module,
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 252..252,
-                delete: 252..252,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+fn main() { let v = <|> }
+"#,
+            expect![[r##"
+                ma bar!(…) macro_rules! bar
+                ma baz!(…) #[macro_export]
+                macro_rules! baz
+                ma foo!(…) macro_rules! foo
+                md m1
+                md m2
+                fn main()  fn main()
+            "##]],
         );
     }
 
     #[test]
     fn completes_both_macro_and_value() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                macro_rules! foo {
-                    () => {}
-                }
-
-                fn foo() {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "macro_rules! foo",
-            },
-            CompletionItem {
-                label: "foo()",
-                source_range: 49..49,
-                delete: 49..49,
-                insert: "foo()$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo()",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn foo() { <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn foo()   fn foo()
+            "#]],
         );
     }
 
     #[test]
     fn completes_macros_as_type() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                macro_rules! foo {
-                    () => {}
-                }
-
-                fn main() {
-                    let x: <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "macro_rules! foo",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 57..57,
-                delete: 57..57,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn main() { let x: <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn main()  fn main()
+            "#]],
         );
     }
 
     #[test]
     fn completes_macros_as_stmt() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                macro_rules! foo {
-                    () => {}
-                }
-
-                fn main() {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo!(…)",
-                source_range: 50..50,
-                delete: 50..50,
-                insert: "foo!($0)",
-                kind: Macro,
-                detail: "macro_rules! foo",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 50..50,
-                delete: 50..50,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! foo { () => {} }
+fn main() { <|> }
+"#,
+            expect![[r#"
+                ma foo!(…) macro_rules! foo
+                fn main()  fn main()
+            "#]],
         );
     }
 
     #[test]
     fn completes_local_item() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /main.rs
-                fn main() {
-                    return f<|>;
-                    fn frobnicate() {}
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "frobnicate()",
-                source_range: 23..24,
-                delete: 23..24,
-                insert: "frobnicate()$0",
-                kind: Function,
-                lookup: "frobnicate",
-                detail: "fn frobnicate()",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 23..24,
-                delete: 23..24,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
-        )
+        check(
+            r#"
+fn main() {
+    return f<|>;
+    fn frobnicate() {}
+}
+"#,
+            expect![[r#"
+                fn frobnicate() fn frobnicate()
+                fn main()       fn main()
+            "#]],
+        );
     }
 
     #[test]
     fn completes_in_simple_macro_1() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                fn quux(x: i32) {
-                    let y = 92;
-                    m!(<|>);
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m!(…)",
-                source_range: 145..145,
-                delete: 145..145,
-                insert: "m!($0)",
-                kind: Macro,
-                detail: "macro_rules! m",
-            },
-            CompletionItem {
-                label: "quux(…)",
-                source_range: 145..145,
-                delete: 145..145,
-                insert: "quux(${1:x})$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux(x: i32)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "x",
-                source_range: 145..145,
-                delete: 145..145,
-                insert: "x",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "y",
-                source_range: 145..145,
-                delete: 145..145,
-                insert: "y",
-                kind: Binding,
-                detail: "i32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(<|>);
+}
+"#,
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
         );
     }
 
     #[test]
     fn completes_in_simple_macro_2() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                macro_rules! m { ($e:expr) => { $e } }
-                fn quux(x: i32) {
-                    let y = 92;
-                    m!(x<|>);
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "m!(…)",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "m!($0)",
-                kind: Macro,
-                detail: "macro_rules! m",
-            },
-            CompletionItem {
-                label: "quux(…)",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "quux(${1:x})$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux(x: i32)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "x",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "x",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "y",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "y",
-                kind: Binding,
-                detail: "i32",
-            },
-        ]
-        "###
+        check(
+            r"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(x<|>);
+}
+",
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
         );
     }
 
     #[test]
     fn completes_in_simple_macro_without_closing_parens() {
-        assert_debug_snapshot!(
-                    do_reference_completion(
-                        r"
-                macro_rules! m { ($e:expr) => { $e } }
-                fn quux(x: i32) {
-                    let y = 92;
-                    m!(x<|>
-                }
-                "
-                    ),
-                    @r###"
-        [
-            CompletionItem {
-                label: "m!(…)",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "m!($0)",
-                kind: Macro,
-                detail: "macro_rules! m",
-            },
-            CompletionItem {
-                label: "quux(…)",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "quux(${1:x})$0",
-                kind: Function,
-                lookup: "quux",
-                detail: "fn quux(x: i32)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "x",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "x",
-                kind: Binding,
-                detail: "i32",
-            },
-            CompletionItem {
-                label: "y",
-                source_range: 145..146,
-                delete: 145..146,
-                insert: "y",
-                kind: Binding,
-                detail: "i32",
-            },
-        ]
-        "###
+        check(
+            r#"
+macro_rules! m { ($e:expr) => { $e } }
+fn quux(x: i32) {
+    let y = 92;
+    m!(x<|>
+}
+"#,
+            expect![[r#"
+                ma m!(…)   macro_rules! m
+                fn quux(…) fn quux(x: i32)
+                bn x       i32
+                bn y       i32
+            "#]],
         );
     }
 
     #[test]
     fn completes_unresolved_uses() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                use spam::Quux;
-
-                fn main() {
-                    <|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Quux",
-                source_range: 82..82,
-                delete: 82..82,
-                insert: "Quux",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 82..82,
-                delete: 82..82,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+        check(
+            r#"
+use spam::Quux;
+
+fn main() { <|> }
+"#,
+            expect![[r#"
+                ?? Quux
+                fn main() fn main()
+            "#]],
         );
     }
     #[test]
     fn completes_enum_variant_matcharm() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Foo {
-                    Bar,
-                    Baz,
-                    Quux
-                }
-
-                fn main() {
-                    let foo = Foo::Quux;
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
 
-                    match foo {
-                        Qu<|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 248..250,
-                delete: 248..250,
-                insert: "Foo",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Foo::Bar",
-                source_range: 248..250,
-                delete: 248..250,
-                insert: "Foo::Bar",
-                kind: EnumVariant,
-                lookup: "Bar",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Baz",
-                source_range: 248..250,
-                delete: 248..250,
-                insert: "Foo::Baz",
-                kind: EnumVariant,
-                lookup: "Baz",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Quux",
-                source_range: 248..250,
-                delete: 248..250,
-                insert: "Foo::Quux",
-                kind: EnumVariant,
-                lookup: "Quux",
-                detail: "()",
-            },
-        ]
-        "###
+fn main() {
+    let foo = Foo::Quux;
+    match foo { Qu<|> }
+}
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+            "#]],
         )
     }
 
     #[test]
     fn completes_enum_variant_iflet() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Foo {
-                    Bar,
-                    Baz,
-                    Quux
-                }
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
 
-                fn main() {
-                    let foo = Foo::Quux;
-
-                    if let Qu<|> = foo {
-
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 219..221,
-                delete: 219..221,
-                insert: "Foo",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Foo::Bar",
-                source_range: 219..221,
-                delete: 219..221,
-                insert: "Foo::Bar",
-                kind: EnumVariant,
-                lookup: "Bar",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Baz",
-                source_range: 219..221,
-                delete: 219..221,
-                insert: "Foo::Baz",
-                kind: EnumVariant,
-                lookup: "Baz",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Quux",
-                source_range: 219..221,
-                delete: 219..221,
-                insert: "Foo::Quux",
-                kind: EnumVariant,
-                lookup: "Quux",
-                detail: "()",
-            },
-        ]
-        "###
+fn main() {
+    let foo = Foo::Quux;
+    if let Qu<|> = foo { }
+}
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+            "#]],
         )
     }
 
     #[test]
     fn completes_enum_variant_basic_expr() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Foo {
-                    Bar,
-                    Baz,
-                    Quux
-                }
-
-                fn main() {
-                    let foo: Foo = Q<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 185..186,
-                delete: 185..186,
-                insert: "Foo",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Foo::Bar",
-                source_range: 185..186,
-                delete: 185..186,
-                insert: "Foo::Bar",
-                kind: EnumVariant,
-                lookup: "Bar",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Baz",
-                source_range: 185..186,
-                delete: 185..186,
-                insert: "Foo::Baz",
-                kind: EnumVariant,
-                lookup: "Baz",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Foo::Quux",
-                source_range: 185..186,
-                delete: 185..186,
-                insert: "Foo::Quux",
-                kind: EnumVariant,
-                lookup: "Quux",
-                detail: "()",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 185..186,
-                delete: 185..186,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+        check(
+            r#"
+enum Foo { Bar, Baz, Quux }
+fn main() { let foo: Foo = Q<|> }
+"#,
+            expect![[r#"
+                en Foo
+                ev Foo::Bar  ()
+                ev Foo::Baz  ()
+                ev Foo::Quux ()
+                fn main()    fn main()
+            "#]],
         )
     }
 
     #[test]
     fn completes_enum_variant_from_module() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                mod m { pub enum E { V } }
-
-                fn f() -> m::E {
-                    V<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "f()",
-                source_range: 98..99,
-                delete: 98..99,
-                insert: "f()$0",
-                kind: Function,
-                lookup: "f",
-                detail: "fn f() -> m::E",
-            },
-            CompletionItem {
-                label: "m",
-                source_range: 98..99,
-                delete: 98..99,
-                insert: "m",
-                kind: Module,
-            },
-            CompletionItem {
-                label: "m::E::V",
-                source_range: 98..99,
-                delete: 98..99,
-                insert: "m::E::V",
-                kind: EnumVariant,
-                lookup: "V",
-                detail: "()",
-            },
-        ]
-        "###
+        check(
+            r#"
+mod m { pub enum E { V } }
+fn f() -> m::E { V<|> }
+"#,
+            expect![[r#"
+                fn f()     fn f() -> m::E
+                md m
+                ev m::E::V ()
+            "#]],
         )
     }
 
     #[test]
     fn dont_complete_attr() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Foo;
-                #[<|>]
-                fn f() {}
-                "
-            ),
-            @r###"[]"###
+        check(
+            r#"
+struct Foo;
+#[<|>]
+fn f() {}
+"#,
+            expect![[""]],
+        )
+    }
+
+    #[test]
+    fn completes_type_or_trait_in_impl_block() {
+        check(
+            r#"
+trait MyTrait {}
+struct MyStruct {}
+
+impl My<|>
+"#,
+            expect![[r#"
+                st MyStruct
+                tt MyTrait
+                tp Self
+            "#]],
         )
     }
 }
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index c4646b727..9e82d6854 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -5,12 +5,17 @@ use ra_db::SourceDatabase;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo::{find_covering_element, find_node_at_offset},
-    ast, match_ast, AstNode,
+    ast, match_ast, AstNode, NodeOrToken,
     SyntaxKind::*,
     SyntaxNode, SyntaxToken, TextRange, TextSize,
 };
 use ra_text_edit::Indel;
 
+use super::patterns::{
+    has_bind_pat_parent, has_block_expr_parent, has_impl_as_prev_sibling, has_impl_parent,
+    has_item_list_or_source_file_parent, has_ref_parent, has_trait_as_prev_sibling,
+    has_trait_parent, if_is_prev, is_in_loop_body, is_match_arm, unsafe_is_prev,
+};
 use crate::{call_info::ActiveParameter, completion::CompletionConfig, FilePosition};
 use test_utils::mark;
 
@@ -19,6 +24,7 @@ use test_utils::mark;
 #[derive(Debug)]
 pub(crate) struct CompletionContext<'a> {
     pub(super) sema: Semantics<'a, RootDatabase>,
+    pub(super) scope: SemanticsScope<'a>,
     pub(super) db: &'a RootDatabase,
     pub(super) config: &'a CompletionConfig,
     pub(super) offset: TextSize,
@@ -48,6 +54,8 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) after_if: bool,
     /// `true` if we are a statement or a last expr in the block.
     pub(super) can_be_stmt: bool,
+    /// `true` if we expect an expression at the cursor position.
+    pub(super) is_expr: bool,
     /// Something is typed at the "top" level, in module or impl/trait.
     pub(super) is_new_item: bool,
     /// The receiver if this is a field or method access, i.e. writing something.<|>
@@ -55,11 +63,25 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) dot_receiver_is_ambiguous_float_literal: bool,
     /// If this is a call (method or function) in particular, i.e. the () are already there.
     pub(super) is_call: bool,
+    /// Like `is_call`, but for tuple patterns.
+    pub(super) is_pattern_call: bool,
     /// If this is a macro call, i.e. the () are already there.
     pub(super) is_macro_call: bool,
     pub(super) is_path_type: bool,
     pub(super) has_type_args: bool,
     pub(super) attribute_under_caret: Option<ast::Attr>,
+    pub(super) unsafe_is_prev: bool,
+    pub(super) if_is_prev: bool,
+    pub(super) block_expr_parent: bool,
+    pub(super) bind_pat_parent: bool,
+    pub(super) ref_pat_parent: bool,
+    pub(super) in_loop_body: bool,
+    pub(super) has_trait_parent: bool,
+    pub(super) has_impl_parent: bool,
+    pub(super) trait_as_prev_sibling: bool,
+    pub(super) impl_as_prev_sibling: bool,
+    pub(super) is_match_arm: bool,
+    pub(super) has_item_list_or_source_file_parent: bool,
 }
 
 impl<'a> CompletionContext<'a> {
@@ -87,8 +109,10 @@ impl<'a> CompletionContext<'a> {
         let original_token =
             original_file.syntax().token_at_offset(position.offset).left_biased()?;
         let token = sema.descend_into_macros(original_token.clone());
+        let scope = sema.scope_at_offset(&token.parent(), position.offset);
         let mut ctx = CompletionContext {
             sema,
+            scope,
             db,
             config,
             original_token,
@@ -110,14 +134,28 @@ impl<'a> CompletionContext<'a> {
             path_prefix: None,
             after_if: false,
             can_be_stmt: false,
+            is_expr: false,
             is_new_item: false,
             dot_receiver: None,
             is_call: false,
+            is_pattern_call: false,
             is_macro_call: false,
             is_path_type: false,
             has_type_args: false,
             dot_receiver_is_ambiguous_float_literal: false,
             attribute_under_caret: None,
+            unsafe_is_prev: false,
+            in_loop_body: false,
+            ref_pat_parent: false,
+            bind_pat_parent: false,
+            block_expr_parent: false,
+            has_trait_parent: false,
+            has_impl_parent: false,
+            trait_as_prev_sibling: false,
+            impl_as_prev_sibling: false,
+            if_is_prev: false,
+            is_match_arm: false,
+            has_item_list_or_source_file_parent: false,
         };
 
         let mut original_file = original_file.syntax().clone();
@@ -159,7 +197,7 @@ impl<'a> CompletionContext<'a> {
                 break;
             }
         }
-
+        ctx.fill_keyword_patterns(&hypothetical_file, offset);
         ctx.fill(&original_file, hypothetical_file, offset);
         Some(ctx)
     }
@@ -167,25 +205,30 @@ impl<'a> CompletionContext<'a> {
     // The range of the identifier that is being completed.
     pub(crate) fn source_range(&self) -> TextRange {
         // check kind of macro-expanded token, but use range of original token
-        match self.token.kind() {
-            // workaroud when completion is triggered by trigger characters.
-            IDENT => self.original_token.text_range(),
-            _ => {
-                // If we haven't characters between keyword and our cursor we take the keyword start range to edit
-                if self.token.kind().is_keyword()
-                    && self.offset == self.original_token.text_range().end()
-                {
-                    mark::hit!(completes_bindings_from_for_with_in_prefix);
-                    TextRange::empty(self.original_token.text_range().start())
-                } else {
-                    TextRange::empty(self.offset)
-                }
-            }
+        if self.token.kind() == IDENT || self.token.kind().is_keyword() {
+            mark::hit!(completes_if_prefix_is_keyword);
+            self.original_token.text_range()
+        } else {
+            TextRange::empty(self.offset)
         }
     }
 
-    pub(crate) fn scope(&self) -> SemanticsScope<'_, RootDatabase> {
-        self.sema.scope_at_offset(&self.token.parent(), self.offset)
+    fn fill_keyword_patterns(&mut self, file_with_fake_ident: &SyntaxNode, offset: TextSize) {
+        let fake_ident_token = file_with_fake_ident.token_at_offset(offset).right_biased().unwrap();
+        let syntax_element = NodeOrToken::Token(fake_ident_token.clone());
+        self.block_expr_parent = has_block_expr_parent(syntax_element.clone());
+        self.unsafe_is_prev = unsafe_is_prev(syntax_element.clone());
+        self.if_is_prev = if_is_prev(syntax_element.clone());
+        self.bind_pat_parent = has_bind_pat_parent(syntax_element.clone());
+        self.ref_pat_parent = has_ref_parent(syntax_element.clone());
+        self.in_loop_body = is_in_loop_body(syntax_element.clone());
+        self.has_trait_parent = has_trait_parent(syntax_element.clone());
+        self.has_impl_parent = has_impl_parent(syntax_element.clone());
+        self.impl_as_prev_sibling = has_impl_as_prev_sibling(syntax_element.clone());
+        self.trait_as_prev_sibling = has_trait_as_prev_sibling(syntax_element.clone());
+        self.is_match_arm = is_match_arm(syntax_element.clone());
+        self.has_item_list_or_source_file_parent =
+            has_item_list_or_source_file_parent(syntax_element.clone());
     }
 
     fn fill(
@@ -330,10 +373,13 @@ impl<'a> CompletionContext<'a> {
                 .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::cast))
                 .is_some();
             self.is_macro_call = path.syntax().parent().and_then(ast::MacroCall::cast).is_some();
+            self.is_pattern_call =
+                path.syntax().parent().and_then(ast::TupleStructPat::cast).is_some();
 
             self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
             self.has_type_args = segment.type_arg_list().is_some();
 
+            #[allow(deprecated)]
             if let Some(path) = hir::Path::from_ast(path.clone()) {
                 if let Some(path_prefix) = path.qualifier() {
                     self.path_prefix = Some(path_prefix);
@@ -364,6 +410,7 @@ impl<'a> CompletionContext<'a> {
                         None
                     })
                     .unwrap_or(false);
+                self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
 
                 if let Some(off) = name_ref.syntax().text_range().start().checked_sub(2.into()) {
                     if let Some(if_expr) =
diff --git a/crates/ra_ide/src/completion/completion_item.rs b/crates/ra_ide/src/completion/completion_item.rs
index cfb7c1e38..7bdda316c 100644
--- a/crates/ra_ide/src/completion/completion_item.rs
+++ b/crates/ra_ide/src/completion/completion_item.rs
@@ -58,7 +58,7 @@ pub struct CompletionItem {
     score: Option<CompletionScore>,
 }
 
-// We use custom debug for CompletionItem to make `insta`'s diffs more readable.
+// We use custom debug for CompletionItem to make snapshot tests more readable.
 impl fmt::Debug for CompletionItem {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         let mut s = f.debug_struct("CompletionItem");
@@ -95,7 +95,7 @@ impl fmt::Debug for CompletionItem {
     }
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Ord, PartialOrd, Eq, PartialEq)]
 pub enum CompletionScore {
     /// If only type match
     TypeMatch,
@@ -123,6 +123,34 @@ pub enum CompletionItemKind {
     TypeParam,
     Macro,
     Attribute,
+    UnresolvedReference,
+}
+
+impl CompletionItemKind {
+    #[cfg(test)]
+    pub(crate) fn tag(&self) -> &'static str {
+        match self {
+            CompletionItemKind::Attribute => "at",
+            CompletionItemKind::Binding => "bn",
+            CompletionItemKind::BuiltinType => "bt",
+            CompletionItemKind::Const => "ct",
+            CompletionItemKind::Enum => "en",
+            CompletionItemKind::EnumVariant => "ev",
+            CompletionItemKind::Field => "fd",
+            CompletionItemKind::Function => "fn",
+            CompletionItemKind::Keyword => "kw",
+            CompletionItemKind::Macro => "ma",
+            CompletionItemKind::Method => "me",
+            CompletionItemKind::Module => "md",
+            CompletionItemKind::Snippet => "sn",
+            CompletionItemKind::Static => "sc",
+            CompletionItemKind::Struct => "st",
+            CompletionItemKind::Trait => "tt",
+            CompletionItemKind::TypeAlias => "ta",
+            CompletionItemKind::TypeParam => "tp",
+            CompletionItemKind::UnresolvedReference => "??",
+        }
+    }
 }
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
diff --git a/crates/ra_ide/src/completion/patterns.rs b/crates/ra_ide/src/completion/patterns.rs
new file mode 100644
index 000000000..b2fe13280
--- /dev/null
+++ b/crates/ra_ide/src/completion/patterns.rs
@@ -0,0 +1,194 @@
+//! Patterns telling us certain facts about current syntax element, they are used in completion context
+
+use ra_syntax::{
+    algo::non_trivia_sibling,
+    ast::{self, LoopBodyOwner},
+    match_ast, AstNode, Direction, NodeOrToken, SyntaxElement,
+    SyntaxKind::*,
+    SyntaxNode, SyntaxToken,
+};
+
+#[cfg(test)]
+use crate::completion::test_utils::check_pattern_is_applicable;
+
+pub(crate) fn has_trait_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == ITEM_LIST)
+        .and_then(|it| it.parent())
+        .filter(|it| it.kind() == TRAIT_DEF)
+        .is_some()
+}
+#[test]
+fn test_has_trait_parent() {
+    check_pattern_is_applicable(r"trait A { f<|> }", has_trait_parent);
+}
+
+pub(crate) fn has_impl_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == ITEM_LIST)
+        .and_then(|it| it.parent())
+        .filter(|it| it.kind() == IMPL_DEF)
+        .is_some()
+}
+#[test]
+fn test_has_impl_parent() {
+    check_pattern_is_applicable(r"impl A { f<|> }", has_impl_parent);
+}
+
+pub(crate) fn has_block_expr_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element).filter(|it| it.kind() == BLOCK_EXPR).is_some()
+}
+#[test]
+fn test_has_block_expr_parent() {
+    check_pattern_is_applicable(r"fn my_fn() { let a = 2; f<|> }", has_block_expr_parent);
+}
+
+pub(crate) fn has_bind_pat_parent(element: SyntaxElement) -> bool {
+    element.ancestors().find(|it| it.kind() == BIND_PAT).is_some()
+}
+#[test]
+fn test_has_bind_pat_parent() {
+    check_pattern_is_applicable(r"fn my_fn(m<|>) {}", has_bind_pat_parent);
+    check_pattern_is_applicable(r"fn my_fn() { let m<|> }", has_bind_pat_parent);
+}
+
+pub(crate) fn has_ref_parent(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element)
+        .filter(|it| it.kind() == REF_PAT || it.kind() == REF_EXPR)
+        .is_some()
+}
+#[test]
+fn test_has_ref_parent() {
+    check_pattern_is_applicable(r"fn my_fn(&m<|>) {}", has_ref_parent);
+    check_pattern_is_applicable(r"fn my() { let &m<|> }", has_ref_parent);
+}
+
+pub(crate) fn has_item_list_or_source_file_parent(element: SyntaxElement) -> bool {
+    let ancestor = not_same_range_ancestor(element);
+    if !ancestor.is_some() {
+        return true;
+    }
+    ancestor.filter(|it| it.kind() == SOURCE_FILE || it.kind() == ITEM_LIST).is_some()
+}
+#[test]
+fn test_has_item_list_or_source_file_parent() {
+    check_pattern_is_applicable(r"i<|>", has_item_list_or_source_file_parent);
+    check_pattern_is_applicable(r"impl { f<|> }", has_item_list_or_source_file_parent);
+}
+
+pub(crate) fn is_match_arm(element: SyntaxElement) -> bool {
+    not_same_range_ancestor(element.clone()).filter(|it| it.kind() == MATCH_ARM).is_some()
+        && previous_sibling_or_ancestor_sibling(element)
+            .and_then(|it| it.into_token())
+            .filter(|it| it.kind() == FAT_ARROW)
+            .is_some()
+}
+#[test]
+fn test_is_match_arm() {
+    check_pattern_is_applicable(r"fn my_fn() { match () { () => m<|> } }", is_match_arm);
+}
+
+pub(crate) fn unsafe_is_prev(element: SyntaxElement) -> bool {
+    element
+        .into_token()
+        .and_then(|it| previous_non_trivia_token(it))
+        .filter(|it| it.kind() == UNSAFE_KW)
+        .is_some()
+}
+#[test]
+fn test_unsafe_is_prev() {
+    check_pattern_is_applicable(r"unsafe i<|>", unsafe_is_prev);
+}
+
+pub(crate) fn if_is_prev(element: SyntaxElement) -> bool {
+    element
+        .into_token()
+        .and_then(|it| previous_non_trivia_token(it))
+        .filter(|it| it.kind() == IF_KW)
+        .is_some()
+}
+#[test]
+fn test_if_is_prev() {
+    check_pattern_is_applicable(r"if l<|>", if_is_prev);
+}
+
+pub(crate) fn has_trait_as_prev_sibling(element: SyntaxElement) -> bool {
+    previous_sibling_or_ancestor_sibling(element).filter(|it| it.kind() == TRAIT_DEF).is_some()
+}
+#[test]
+fn test_has_trait_as_prev_sibling() {
+    check_pattern_is_applicable(r"trait A w<|> {}", has_trait_as_prev_sibling);
+}
+
+pub(crate) fn has_impl_as_prev_sibling(element: SyntaxElement) -> bool {
+    previous_sibling_or_ancestor_sibling(element).filter(|it| it.kind() == IMPL_DEF).is_some()
+}
+#[test]
+fn test_has_impl_as_prev_sibling() {
+    check_pattern_is_applicable(r"impl A w<|> {}", has_impl_as_prev_sibling);
+}
+
+pub(crate) fn is_in_loop_body(element: SyntaxElement) -> bool {
+    let leaf = match element {
+        NodeOrToken::Node(node) => node,
+        NodeOrToken::Token(token) => token.parent(),
+    };
+    for node in leaf.ancestors() {
+        if node.kind() == FN_DEF || node.kind() == LAMBDA_EXPR {
+            break;
+        }
+        let loop_body = match_ast! {
+            match node {
+                ast::ForExpr(it) => it.loop_body(),
+                ast::WhileExpr(it) => it.loop_body(),
+                ast::LoopExpr(it) => it.loop_body(),
+                _ => None,
+            }
+        };
+        if let Some(body) = loop_body {
+            if body.syntax().text_range().contains_range(leaf.text_range()) {
+                return true;
+            }
+        }
+    }
+    false
+}
+
+fn not_same_range_ancestor(element: SyntaxElement) -> Option<SyntaxNode> {
+    element
+        .ancestors()
+        .take_while(|it| it.text_range() == element.text_range())
+        .last()
+        .and_then(|it| it.parent())
+}
+
+fn previous_non_trivia_token(token: SyntaxToken) -> Option<SyntaxToken> {
+    let mut token = token.prev_token();
+    while let Some(inner) = token.clone() {
+        if !inner.kind().is_trivia() {
+            return Some(inner);
+        } else {
+            token = inner.prev_token();
+        }
+    }
+    None
+}
+
+fn previous_sibling_or_ancestor_sibling(element: SyntaxElement) -> Option<SyntaxElement> {
+    let token_sibling = non_trivia_sibling(element.clone(), Direction::Prev);
+    if let Some(sibling) = token_sibling {
+        Some(sibling)
+    } else {
+        // if not trying to find first ancestor which has such a sibling
+        let node = match element {
+            NodeOrToken::Node(node) => node,
+            NodeOrToken::Token(token) => token.parent(),
+        };
+        let range = node.text_range();
+        let top_node = node.ancestors().take_while(|it| it.text_range() == range).last()?;
+        let prev_sibling_node = top_node.ancestors().find(|it| {
+            non_trivia_sibling(NodeOrToken::Node(it.to_owned()), Direction::Prev).is_some()
+        })?;
+        non_trivia_sibling(NodeOrToken::Node(prev_sibling_node), Direction::Prev)
+    }
+}
diff --git a/crates/ra_ide/src/completion/presentation.rs b/crates/ra_ide/src/completion/presentation.rs
index 61565c84f..64349dcb8 100644
--- a/crates/ra_ide/src/completion/presentation.rs
+++ b/crates/ra_ide/src/completion/presentation.rs
@@ -1,4 +1,5 @@
 //! This modules takes care of rendering various definitions as completion items.
+//! It also handles scoring (sorting) completions.
 
 use hir::{Docs, HasAttrs, HasSource, HirDisplay, ModPath, ScopeDef, StructKind, Type};
 use ra_syntax::ast::NameOwner;
@@ -78,11 +79,10 @@ impl Completions {
                 return self.add_macro(ctx, Some(local_name), *mac);
             }
             ScopeDef::Unknown => {
-                return self.add(CompletionItem::new(
-                    CompletionKind::Reference,
-                    ctx.source_range(),
-                    local_name,
-                ));
+                return self.add(
+                    CompletionItem::new(CompletionKind::Reference, ctx.source_range(), local_name)
+                        .kind(CompletionItemKind::UnresolvedReference),
+                );
             }
         };
 
@@ -173,6 +173,7 @@ impl Completions {
                 builder
                     .insert_snippet(cap, format!("{}!{}$0{}", name, bra, ket))
                     .label(format!("{}!{}…{}", name, bra, ket))
+                    .lookup_by(format!("{}!", name))
             }
             None if needs_bang => builder.insert_text(format!("{}!", name)),
             _ => {
@@ -314,6 +315,7 @@ impl Completions {
         }
 
         if variant_kind == StructKind::Tuple {
+            mark::hit!(inserts_parens_for_tuple_enums);
             let params = Params::Anonymous(variant.fields(ctx.db).len());
             res = res.add_call_parens(ctx, qualified_name, params)
         }
@@ -330,14 +332,14 @@ pub(crate) fn compute_score(
     // FIXME: this should not fall back to string equality.
     let ty = &ty.display(ctx.db).to_string();
     let (active_name, active_type) = if let Some(record_field) = &ctx.record_field_syntax {
-        mark::hit!(test_struct_field_completion_in_record_lit);
+        mark::hit!(record_field_type_match);
         let (struct_field, _local) = ctx.sema.resolve_record_field(record_field)?;
         (
             struct_field.name(ctx.db).to_string(),
             struct_field.signature_ty(ctx.db).display(ctx.db).to_string(),
         )
     } else if let Some(active_parameter) = &ctx.active_parameter {
-        mark::hit!(test_struct_field_completion_in_func_call);
+        mark::hit!(active_param_type_match);
         (active_parameter.name.clone(), active_parameter.ty.clone())
     } else {
         return None;
@@ -382,13 +384,22 @@ impl Builder {
         if !ctx.config.add_call_parenthesis {
             return self;
         }
-        if ctx.use_item_syntax.is_some() || ctx.is_call {
+        if ctx.use_item_syntax.is_some() {
+            mark::hit!(no_parens_in_use_item);
+            return self;
+        }
+        if ctx.is_pattern_call {
+            mark::hit!(dont_duplicate_pattern_parens);
+            return self;
+        }
+        if ctx.is_call {
             return self;
         }
 
         // Don't add parentheses if the expected type is some function reference.
         if let Some(ty) = &ctx.expected_type {
             if ty.is_fn() {
+                mark::hit!(no_call_parens_if_fn_ptr_needed);
                 return self;
             }
         }
@@ -413,7 +424,10 @@ impl Builder {
                         .sep_by(", ");
                     format!("{}({})$0", name, function_params_snippet)
                 }
-                _ => format!("{}($0)", name),
+                _ => {
+                    mark::hit!(suppress_arg_snippets);
+                    format!("{}($0)", name)
+                }
             };
 
             (snippet, format!("{}(…)", name))
@@ -456,1061 +470,750 @@ fn guess_macro_braces(macro_name: &str, docs: &str) -> (&'static str, &'static s
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use std::cmp::Reverse;
+
+    use expect::{expect, Expect};
     use test_utils::mark;
 
-    use crate::completion::{
-        test_utils::{do_completion, do_completion_with_options},
-        CompletionConfig, CompletionItem, CompletionKind,
+    use crate::{
+        completion::{
+            test_utils::{
+                check_edit, check_edit_with_config, do_completion, get_all_completion_items,
+            },
+            CompletionConfig, CompletionKind,
+        },
+        CompletionScore,
     };
 
-    fn do_reference_completion(ra_fixture: &str) -> Vec<CompletionItem> {
-        do_completion(ra_fixture, CompletionKind::Reference)
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = do_completion(ra_fixture, CompletionKind::Reference);
+        expect.assert_debug_eq(&actual);
     }
 
-    fn do_reference_completion_with_options(
-        ra_fixture: &str,
-        options: CompletionConfig,
-    ) -> Vec<CompletionItem> {
-        do_completion_with_options(ra_fixture, CompletionKind::Reference, &options)
+    fn check_scores(ra_fixture: &str, expect: Expect) {
+        fn display_score(score: Option<CompletionScore>) -> &'static str {
+            match score {
+                Some(CompletionScore::TypeMatch) => "[type]",
+                Some(CompletionScore::TypeAndNameMatch) => "[type+name]",
+                None => "[]".into(),
+            }
+        }
+
+        let mut completions = get_all_completion_items(CompletionConfig::default(), ra_fixture);
+        completions.sort_by_key(|it| (Reverse(it.score()), it.label().to_string()));
+        let actual = completions
+            .into_iter()
+            .filter(|it| it.completion_kind == CompletionKind::Reference)
+            .map(|it| {
+                let tag = it.kind().unwrap().tag();
+                let score = display_score(it.score());
+                format!("{} {} {}\n", tag, it.label(), score)
+            })
+            .collect::<String>();
+        expect.assert_eq(&actual);
     }
 
     #[test]
-    fn enum_detail_includes_names_for_record() {
-        assert_debug_snapshot!(
-        do_reference_completion(
+    fn enum_detail_includes_record_fields() {
+        check(
             r#"
-                enum Foo {
-                    Foo {x: i32, y: i32}
-                }
-
-                fn main() { Foo::Fo<|> }
-                "#,
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 121..123,
-                delete: 121..123,
-                insert: "Foo",
-                kind: EnumVariant,
-                detail: "{ x: i32, y: i32 }",
-            },
-        ]"###
+enum Foo { Foo { x: i32, y: i32 } }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo",
+                        source_range: 54..56,
+                        delete: 54..56,
+                        insert: "Foo",
+                        kind: EnumVariant,
+                        detail: "{ x: i32, y: i32 }",
+                    },
+                ]
+            "#]],
         );
     }
 
     #[test]
-    fn enum_detail_doesnt_include_names_for_tuple() {
-        assert_debug_snapshot!(
-        do_reference_completion(
+    fn enum_detail_doesnt_include_tuple_fields() {
+        check(
             r#"
-                enum Foo {
-                    Foo (i32, i32)
-                }
-
-                fn main() { Foo::Fo<|> }
-                "#,
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "Foo(…)",
-                source_range: 115..117,
-                delete: 115..117,
-                insert: "Foo($0)",
-                kind: EnumVariant,
-                lookup: "Foo",
-                detail: "(i32, i32)",
-                trigger_call_info: true,
-            },
-        ]"###
+enum Foo { Foo (i32, i32) }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo(…)",
+                        source_range: 46..48,
+                        delete: 46..48,
+                        insert: "Foo($0)",
+                        kind: EnumVariant,
+                        lookup: "Foo",
+                        detail: "(i32, i32)",
+                        trigger_call_info: true,
+                    },
+                ]
+            "#]],
         );
     }
 
     #[test]
     fn enum_detail_just_parentheses_for_unit() {
-        assert_debug_snapshot!(
-        do_reference_completion(
+        check(
             r#"
-                enum Foo {
-                    Foo
-                }
-
-                fn main() { Foo::Fo<|> }
-                "#,
-        ),
-        @r###"
-        [
-            CompletionItem {
-                label: "Foo",
-                source_range: 104..106,
-                delete: 104..106,
-                insert: "Foo",
-                kind: EnumVariant,
-                detail: "()",
-            },
-        ]"###
+enum Foo { Foo }
+
+fn main() { Foo::Fo<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "Foo",
+                        source_range: 35..37,
+                        delete: 35..37,
+                        insert: "Foo",
+                        kind: EnumVariant,
+                        detail: "()",
+                    },
+                ]
+            "#]],
         );
     }
 
     #[test]
     fn sets_deprecated_flag_in_completion_items() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r#"
-                #[deprecated]
-                fn something_deprecated() {}
-
-                #[deprecated(since = "1.0.0")]
-                fn something_else_deprecated() {}
-
-                fn main() { som<|> }
-                "#,
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "main()",
-                source_range: 203..206,
-                delete: 203..206,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-            CompletionItem {
-                label: "something_deprecated()",
-                source_range: 203..206,
-                delete: 203..206,
-                insert: "something_deprecated()$0",
-                kind: Function,
-                lookup: "something_deprecated",
-                detail: "fn something_deprecated()",
-                deprecated: true,
-            },
-            CompletionItem {
-                label: "something_else_deprecated()",
-                source_range: 203..206,
-                delete: 203..206,
-                insert: "something_else_deprecated()$0",
-                kind: Function,
-                lookup: "something_else_deprecated",
-                detail: "fn something_else_deprecated()",
-                deprecated: true,
-            },
-        ]
-        "###
+        check(
+            r#"
+#[deprecated]
+fn something_deprecated() {}
+#[deprecated(since = "1.0.0")]
+fn something_else_deprecated() {}
+
+fn main() { som<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "main()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "main()$0",
+                        kind: Function,
+                        lookup: "main",
+                        detail: "fn main()",
+                    },
+                    CompletionItem {
+                        label: "something_deprecated()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "something_deprecated()$0",
+                        kind: Function,
+                        lookup: "something_deprecated",
+                        detail: "fn something_deprecated()",
+                        deprecated: true,
+                    },
+                    CompletionItem {
+                        label: "something_else_deprecated()",
+                        source_range: 121..124,
+                        delete: 121..124,
+                        insert: "something_else_deprecated()$0",
+                        kind: Function,
+                        lookup: "something_else_deprecated",
+                        detail: "fn something_else_deprecated()",
+                        deprecated: true,
+                    },
+                ]
+            "#]],
+        );
+
+        check(
+            r#"
+struct A { #[deprecated] the_field: u32 }
+fn foo() { A { the<|> } }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "the_field",
+                        source_range: 57..60,
+                        delete: 57..60,
+                        insert: "the_field",
+                        kind: Field,
+                        detail: "u32",
+                        deprecated: true,
+                    },
+                ]
+            "#]],
         );
     }
 
     #[test]
+    fn renders_docs() {
+        check(
+            r#"
+struct S {
+    /// Field docs
+    foo:
+}
+impl S {
+    /// Method docs
+    fn bar(self) { self.<|> }
+}"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "bar()",
+                        source_range: 94..94,
+                        delete: 94..94,
+                        insert: "bar()$0",
+                        kind: Method,
+                        lookup: "bar",
+                        detail: "fn bar(self)",
+                        documentation: Documentation(
+                            "Method docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "foo",
+                        source_range: 94..94,
+                        delete: 94..94,
+                        insert: "foo",
+                        kind: Field,
+                        detail: "{unknown}",
+                        documentation: Documentation(
+                            "Field docs",
+                        ),
+                    },
+                ]
+            "#]],
+        );
+
+        check(
+            r#"
+use self::my<|>;
+
+/// mod docs
+mod my { }
+
+/// enum docs
+enum E {
+    /// variant docs
+    V
+}
+use self::E::*;
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "E",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "E",
+                        kind: Enum,
+                        documentation: Documentation(
+                            "enum docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "V",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "V",
+                        kind: EnumVariant,
+                        detail: "()",
+                        documentation: Documentation(
+                            "variant docs",
+                        ),
+                    },
+                    CompletionItem {
+                        label: "my",
+                        source_range: 10..12,
+                        delete: 10..12,
+                        insert: "my",
+                        kind: Module,
+                        documentation: Documentation(
+                            "mod docs",
+                        ),
+                    },
+                ]
+            "#]],
+        )
+    }
+
+    #[test]
+    fn dont_render_attrs() {
+        check(
+            r#"
+struct S;
+impl S {
+    #[inline]
+    fn the_method(&self) { }
+}
+fn foo(s: S) { s.<|> }
+"#,
+            expect![[r#"
+                [
+                    CompletionItem {
+                        label: "the_method()",
+                        source_range: 81..81,
+                        delete: 81..81,
+                        insert: "the_method()$0",
+                        kind: Method,
+                        lookup: "the_method",
+                        detail: "fn the_method(&self)",
+                    },
+                ]
+            "#]],
+        )
+    }
+
+    #[test]
     fn inserts_parens_for_function_calls() {
         mark::check!(inserts_parens_for_function_calls);
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn no_args() {}
-                fn main() { no_<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "main()",
-                source_range: 61..64,
-                delete: 61..64,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-            CompletionItem {
-                label: "no_args()",
-                source_range: 61..64,
-                delete: 61..64,
-                insert: "no_args()$0",
-                kind: Function,
-                lookup: "no_args",
-                detail: "fn no_args()",
-            },
-        ]
-        "###
-        );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn with_args(x: i32, y: String) {}
-                fn main() { with_<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "main()",
-                source_range: 80..85,
-                delete: 80..85,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-            CompletionItem {
-                label: "with_args(…)",
-                source_range: 80..85,
-                delete: 80..85,
-                insert: "with_args(${1:x}, ${2:y})$0",
-                kind: Function,
-                lookup: "with_args",
-                detail: "fn with_args(x: i32, y: String)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+        check_edit(
+            "no_args",
+            r#"
+fn no_args() {}
+fn main() { no_<|> }
+"#,
+            r#"
+fn no_args() {}
+fn main() { no_args()$0 }
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn with_ignored_args(_foo: i32, ___bar: bool, ho_ge_: String) {}
-                fn main() { with_<|> }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "main()",
-                source_range: 110..115,
-                delete: 110..115,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-            CompletionItem {
-                label: "with_ignored_args(…)",
-                source_range: 110..115,
-                delete: 110..115,
-                insert: "with_ignored_args(${1:foo}, ${2:bar}, ${3:ho_ge_})$0",
-                kind: Function,
-                lookup: "with_ignored_args",
-                detail: "fn with_ignored_args(_foo: i32, ___bar: bool, ho_ge_: String)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+
+        check_edit(
+            "with_args",
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_<|> }
+"#,
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_args(${1:x}, ${2:y})$0 }
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct S {}
-                impl S {
-                    fn foo(&self) {}
-                }
-                fn bar(s: &S) {
-                    s.f<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo()",
-                source_range: 163..164,
-                delete: 163..164,
-                insert: "foo()$0",
-                kind: Method,
-                lookup: "foo",
-                detail: "fn foo(&self)",
-            },
-        ]
-        "###
+
+        check_edit(
+            "foo",
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn bar(s: &S) { s.f<|> }
+"#,
+            r#"
+struct S;
+impl S {
+    fn foo(&self) {}
+}
+fn bar(s: &S) { s.foo()$0 }
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct S {}
-                impl S {
-                    fn foo_ignored_args(&self, _a: bool, b: i32) {}
-                }
-                fn bar(s: &S) {
-                    s.f<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo_ignored_args(…)",
-                source_range: 194..195,
-                delete: 194..195,
-                insert: "foo_ignored_args(${1:a}, ${2:b})$0",
-                kind: Method,
-                lookup: "foo_ignored_args",
-                detail: "fn foo_ignored_args(&self, _a: bool, b: i32)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+
+        check_edit(
+            "foo",
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {}
+}
+fn bar(s: &S) {
+    s.f<|>
+}
+"#,
+            r#"
+struct S {}
+impl S {
+    fn foo(&self, x: i32) {}
+}
+fn bar(s: &S) {
+    s.foo(${1:x})$0
+}
+"#,
         );
     }
 
     #[test]
-    fn inserts_parens_for_tuple_enums() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Option<T> { Some(T), None }
-                use Option::*;
-                fn main() -> Option<i32> {
-                    Som<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "None",
-                source_range: 144..147,
-                delete: 144..147,
-                insert: "None",
-                kind: EnumVariant,
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Option",
-                source_range: 144..147,
-                delete: 144..147,
-                insert: "Option",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Some(…)",
-                source_range: 144..147,
-                delete: 144..147,
-                insert: "Some($0)",
-                kind: EnumVariant,
-                lookup: "Some",
-                detail: "(T)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 144..147,
-                delete: 144..147,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main() -> Option<i32>",
-            },
-        ]
-        "###
-        );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                enum Option<T> { Some(T), None }
-                use Option::*;
-                fn main(value: Option<i32>) {
-                    match value {
-                        Som<|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "None",
-                source_range: 185..188,
-                delete: 185..188,
-                insert: "None",
-                kind: EnumVariant,
-                detail: "()",
-            },
-            CompletionItem {
-                label: "Option",
-                source_range: 185..188,
-                delete: 185..188,
-                insert: "Option",
-                kind: Enum,
-            },
-            CompletionItem {
-                label: "Some(…)",
-                source_range: 185..188,
-                delete: 185..188,
-                insert: "Some($0)",
-                kind: EnumVariant,
-                lookup: "Some",
-                detail: "(T)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+    fn suppress_arg_snippets() {
+        mark::check!(suppress_arg_snippets);
+        check_edit_with_config(
+            CompletionConfig { add_call_argument_snippets: false, ..CompletionConfig::default() },
+            "with_args",
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_<|> }
+"#,
+            r#"
+fn with_args(x: i32, y: String) {}
+fn main() { with_args($0) }
+"#,
         );
     }
 
     #[test]
-    fn no_call_parens_if_fn_ptr_needed() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                fn somefn(with: u8, a: u8, lot: u8, of: u8, args: u8) {}
-
-                struct ManualVtable {
-                    method: fn(u8, u8, u8, u8, u8),
-                }
+    fn strips_underscores_from_args() {
+        check_edit(
+            "foo",
+            r#"
+fn foo(_foo: i32, ___bar: bool, ho_ge_: String) {}
+fn main() { f<|> }
+"#,
+            r#"
+fn foo(_foo: i32, ___bar: bool, ho_ge_: String) {}
+fn main() { foo(${1:foo}, ${2:bar}, ${3:ho_ge_})$0 }
+"#,
+        );
+    }
 
-                fn main() -> ManualVtable {
-                    ManualVtable {
-                        method: some<|>
-                    }
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "ManualVtable",
-                source_range: 295..299,
-                delete: 295..299,
-                insert: "ManualVtable",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "main",
-                source_range: 295..299,
-                delete: 295..299,
-                insert: "main",
-                kind: Function,
-                detail: "fn main() -> ManualVtable",
-            },
-            CompletionItem {
-                label: "somefn",
-                source_range: 295..299,
-                delete: 295..299,
-                insert: "somefn",
-                kind: Function,
-                detail: "fn somefn(with: u8, a: u8, lot: u8, of: u8, args: u8)",
-            },
-        ]
-        "###
+    #[test]
+    fn inserts_parens_for_tuple_enums() {
+        mark::check!(inserts_parens_for_tuple_enums);
+        check_edit(
+            "Some",
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main() -> Option<i32> {
+    Som<|>
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main() -> Option<i32> {
+    Some($0)
+}
+"#,
+        );
+        check_edit(
+            "Some",
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main(value: Option<i32>) {
+    match value {
+        Som<|>
+    }
+}
+"#,
+            r#"
+enum Option<T> { Some(T), None }
+use Option::*;
+fn main(value: Option<i32>) {
+    match value {
+        Some($0)
+    }
+}
+"#,
         );
     }
 
     #[test]
-    fn arg_snippets_for_method_call() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct S {}
-                impl S {
-                    fn foo(&self, x: i32) {}
-                }
-                fn bar(s: &S) {
-                    s.f<|>
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 171..172,
-                delete: 171..172,
-                insert: "foo(${1:x})$0",
-                kind: Method,
-                lookup: "foo",
-                detail: "fn foo(&self, x: i32)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
-        )
+    fn dont_duplicate_pattern_parens() {
+        mark::check!(dont_duplicate_pattern_parens);
+        check_edit(
+            "Var",
+            r#"
+enum E { Var(i32) }
+fn main() {
+    match E::Var(92) {
+        E::<|>(92) => (),
+    }
+}
+"#,
+            r#"
+enum E { Var(i32) }
+fn main() {
+    match E::Var(92) {
+        E::Var(92) => (),
+    }
+}
+"#,
+        );
     }
 
     #[test]
-    fn no_arg_snippets_for_method_call() {
-        assert_debug_snapshot!(
-            do_reference_completion_with_options(
-                r"
-                struct S {}
-                impl S {
-                    fn foo(&self, x: i32) {}
-                }
-                fn bar(s: &S) {
-                    s.f<|>
-                }
-                ",
-                CompletionConfig {
-                    add_call_argument_snippets: false,
-                    .. Default::default()
-                }
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 171..172,
-                delete: 171..172,
-                insert: "foo($0)",
-                kind: Method,
-                lookup: "foo",
-                detail: "fn foo(&self, x: i32)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
-        )
+    fn no_call_parens_if_fn_ptr_needed() {
+        mark::check!(no_call_parens_if_fn_ptr_needed);
+        check_edit(
+            "foo",
+            r#"
+fn foo(foo: u8, bar: u8) {}
+struct ManualVtable { f: fn(u8, u8) }
+
+fn main() -> ManualVtable {
+    ManualVtable { f: f<|> }
+}
+"#,
+            r#"
+fn foo(foo: u8, bar: u8) {}
+struct ManualVtable { f: fn(u8, u8) }
+
+fn main() -> ManualVtable {
+    ManualVtable { f: foo }
+}
+"#,
+        );
     }
 
     #[test]
-    fn dont_render_function_parens_in_use_item() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                mod m { pub fn foo() {} }
-                use crate::m::f<|>;
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "foo",
-                source_range: 40..41,
-                delete: 40..41,
-                insert: "foo",
-                kind: Function,
-                detail: "pub fn foo()",
-            },
-        ]
-        "###
+    fn no_parens_in_use_item() {
+        mark::check!(no_parens_in_use_item);
+        check_edit(
+            "foo",
+            r#"
+mod m { pub fn foo() {} }
+use crate::m::f<|>;
+"#,
+            r#"
+mod m { pub fn foo() {} }
+use crate::m::foo;
+"#,
         );
     }
 
     #[test]
-    fn dont_render_function_parens_if_already_call() {
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                fn frobnicate() {}
-                fn main() {
-                    frob<|>();
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "frobnicate",
-                source_range: 35..39,
-                delete: 35..39,
-                insert: "frobnicate",
-                kind: Function,
-                detail: "fn frobnicate()",
-            },
-            CompletionItem {
-                label: "main",
-                source_range: 35..39,
-                delete: 35..39,
-                insert: "main",
-                kind: Function,
-                detail: "fn main()",
-            },
-        ]
-        "###
+    fn no_parens_in_call() {
+        check_edit(
+            "foo",
+            r#"
+fn foo(x: i32) {}
+fn main() { f<|>(); }
+"#,
+            r#"
+fn foo(x: i32) {}
+fn main() { foo(); }
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                "
-                //- /lib.rs
-                struct Foo {}
-                impl Foo { fn new() -> Foo {} }
-                fn main() {
-                    Foo::ne<|>();
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "new",
-                source_range: 67..69,
-                delete: 67..69,
-                insert: "new",
-                kind: Function,
-                detail: "fn new() -> Foo",
-            },
-        ]
-        "###
+        check_edit(
+            "foo",
+            r#"
+struct Foo;
+impl Foo { fn foo(&self){} }
+fn f(foo: &Foo) { foo.f<|>(); }
+"#,
+            r#"
+struct Foo;
+impl Foo { fn foo(&self){} }
+fn f(foo: &Foo) { foo.foo(); }
+"#,
         );
     }
 
     #[test]
     fn inserts_angle_brackets_for_generics() {
         mark::check!(inserts_angle_brackets_for_generics);
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Vec<T> {}
-                fn foo(xs: Ve<|>)
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Vec<…>",
-                source_range: 61..63,
-                delete: 61..63,
-                insert: "Vec<$0>",
-                kind: Struct,
-                lookup: "Vec",
-            },
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 61..63,
-                delete: 61..63,
-                insert: "foo(${1:xs})$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo(xs: Ve)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T> {}
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+struct Vec<T> {}
+fn foo(xs: Vec<$0>)
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                type Vec<T> = (T,);
-                fn foo(xs: Ve<|>)
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Vec<…>",
-                source_range: 64..66,
-                delete: 64..66,
-                insert: "Vec<$0>",
-                kind: TypeAlias,
-                lookup: "Vec",
-            },
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 64..66,
-                delete: 64..66,
-                insert: "foo(${1:xs})$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo(xs: Ve)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+        check_edit(
+            "Vec",
+            r#"
+type Vec<T> = (T,);
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+type Vec<T> = (T,);
+fn foo(xs: Vec<$0>)
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Vec<T = i128> {}
-                fn foo(xs: Ve<|>)
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Vec",
-                source_range: 68..70,
-                delete: 68..70,
-                insert: "Vec",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 68..70,
-                delete: 68..70,
-                insert: "foo(${1:xs})$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo(xs: Ve)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T = i128> {}
+fn foo(xs: Ve<|>)
+"#,
+            r#"
+struct Vec<T = i128> {}
+fn foo(xs: Vec)
+"#,
         );
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                struct Vec<T> {}
-                fn foo(xs: Ve<|><i128>)
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "Vec",
-                source_range: 61..63,
-                delete: 61..63,
-                insert: "Vec",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "foo(…)",
-                source_range: 61..63,
-                delete: 61..63,
-                insert: "foo(${1:xs})$0",
-                kind: Function,
-                lookup: "foo",
-                detail: "fn foo(xs: Ve<i128>)",
-                trigger_call_info: true,
-            },
-        ]
-        "###
+        check_edit(
+            "Vec",
+            r#"
+struct Vec<T> {}
+fn foo(xs: Ve<|><i128>)
+"#,
+            r#"
+struct Vec<T> {}
+fn foo(xs: Vec<i128>)
+"#,
         );
     }
 
     #[test]
     fn dont_insert_macro_call_parens_unncessary() {
         mark::check!(dont_insert_macro_call_parens_unncessary);
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                //- /main.rs
-                use foo::<|>;
-
-                //- /foo/lib.rs
-                #[macro_export]
-                macro_rules frobnicate {
-                    () => ()
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "frobnicate!",
-                source_range: 9..9,
-                delete: 9..9,
-                insert: "frobnicate",
-                kind: Macro,
-                detail: "#[macro_export]\nmacro_rules! frobnicate",
-            },
-        ]
-        "###
+        check_edit(
+            "frobnicate!",
+            r#"
+//- /main.rs
+use foo::<|>;
+//- /foo/lib.rs
+#[macro_export]
+macro_rules frobnicate { () => () }
+"#,
+            r#"
+use foo::frobnicate;
+"#,
         );
 
-        assert_debug_snapshot!(
-            do_reference_completion(
-                r"
-                //- /main.rs
-                macro_rules frobnicate {
-                    () => ()
-                }
-                fn main() {
-                    frob<|>!();
-                }
-                "
-            ),
-            @r###"
-        [
-            CompletionItem {
-                label: "frobnicate!",
-                source_range: 56..60,
-                delete: 56..60,
-                insert: "frobnicate",
-                kind: Macro,
-                detail: "macro_rules! frobnicate",
-            },
-            CompletionItem {
-                label: "main()",
-                source_range: 56..60,
-                delete: 56..60,
-                insert: "main()$0",
-                kind: Function,
-                lookup: "main",
-                detail: "fn main()",
-            },
-        ]
-        "###
+        check_edit(
+            "frobnicate!",
+            r#"
+macro_rules frobnicate { () => () }
+fn main() { frob<|>!(); }
+"#,
+            r#"
+macro_rules frobnicate { () => () }
+fn main() { frobnicate!(); }
+"#,
         );
     }
 
     #[test]
-    fn test_struct_field_completion_in_func_call() {
-        mark::check!(test_struct_field_completion_in_func_call);
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                struct A { another_field: i64, the_field: u32, my_string: String }
-                fn test(my_param: u32) -> u32 { my_param }
-                fn foo(a: A) {
-                    test(a.<|>)
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "another_field",
-                source_range: 201..201,
-                delete: 201..201,
-                insert: "another_field",
-                kind: Field,
-                detail: "i64",
-            },
-            CompletionItem {
-                label: "my_string",
-                source_range: 201..201,
-                delete: 201..201,
-                insert: "my_string",
-                kind: Field,
-                detail: "{unknown}",
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 201..201,
-                delete: 201..201,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-                score: TypeMatch,
-            },
-        ]
-        "###
+    fn active_param_score() {
+        mark::check!(active_param_type_match);
+        check_scores(
+            r#"
+struct S { foo: i64, bar: u32, baz: u32 }
+fn test(bar: u32) { }
+fn foo(s: S) { test(s.<|>) }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
         );
     }
 
     #[test]
-    fn test_struct_field_completion_in_func_call_with_type_and_name() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                struct A { another_field: i64, another_good_type: u32, the_field: u32 }
-                fn test(the_field: u32) -> u32 { the_field }
-                fn foo(a: A) {
-                    test(a.<|>)
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "another_field",
-                source_range: 208..208,
-                delete: 208..208,
-                insert: "another_field",
-                kind: Field,
-                detail: "i64",
-            },
-            CompletionItem {
-                label: "another_good_type",
-                source_range: 208..208,
-                delete: 208..208,
-                insert: "another_good_type",
-                kind: Field,
-                detail: "u32",
-                score: TypeMatch,
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 208..208,
-                delete: 208..208,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-                score: TypeAndNameMatch,
-            },
-        ]
-        "###
-        );
+    fn record_field_scores() {
+        mark::check!(record_field_type_match);
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn foo(a: A) { B { bar: a.<|> }; }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
+        )
     }
 
     #[test]
-    fn test_struct_field_completion_in_record_lit() {
-        mark::check!(test_struct_field_completion_in_record_lit);
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                struct A { another_field: i64, another_good_type: u32, the_field: u32 }
-                struct B { my_string: String, my_vec: Vec<u32>, the_field: u32 }
-                fn foo(a: A) {
-                    let b = B {
-                        the_field: a.<|>
-                    };
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "another_field",
-                source_range: 270..270,
-                delete: 270..270,
-                insert: "another_field",
-                kind: Field,
-                detail: "i64",
-            },
-            CompletionItem {
-                label: "another_good_type",
-                source_range: 270..270,
-                delete: 270..270,
-                insert: "another_good_type",
-                kind: Field,
-                detail: "u32",
-                score: TypeMatch,
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 270..270,
-                delete: 270..270,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-                score: TypeAndNameMatch,
-            },
-        ]
-        "###
+    fn record_field_and_call_scores() {
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn f(foo: i64) {  }
+fn foo(a: A) { B { bar: f(a.<|>) }; }
+"#,
+            expect![[r#"
+                fd foo [type+name]
+                fd bar []
+                fd baz []
+            "#]],
         );
-    }
-
-    #[test]
-    fn test_struct_field_completion_in_record_lit_and_fn_call() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                struct A { another_field: i64, another_good_type: u32, the_field: u32 }
-                struct B { my_string: String, my_vec: Vec<u32>, the_field: u32 }
-                fn test(the_field: i64) -> i64 { the_field }
-                fn foo(a: A) {
-                    let b = B {
-                        the_field: test(a.<|>)
-                    };
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "another_field",
-                source_range: 336..336,
-                delete: 336..336,
-                insert: "another_field",
-                kind: Field,
-                detail: "i64",
-                score: TypeMatch,
-            },
-            CompletionItem {
-                label: "another_good_type",
-                source_range: 336..336,
-                delete: 336..336,
-                insert: "another_good_type",
-                kind: Field,
-                detail: "u32",
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 336..336,
-                delete: 336..336,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-            },
-        ]
-        "###
+        check_scores(
+            r#"
+struct A { foo: i64, bar: u32, baz: u32 }
+struct B { x: (), y: f32, bar: u32 }
+fn f(foo: i64) {  }
+fn foo(a: A) { f(B { bar: a.<|> }); }
+"#,
+            expect![[r#"
+                fd bar [type+name]
+                fd baz [type]
+                fd foo []
+            "#]],
         );
     }
 
     #[test]
-    fn test_struct_field_completion_in_fn_call_and_record_lit() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                struct A { another_field: i64, another_good_type: u32, the_field: u32 }
-                struct B { my_string: String, my_vec: Vec<u32>, the_field: u32 }
-                fn test(the_field: i64) -> i64 { the_field }
-                fn foo(a: A) {
-                    test(B {
-                        the_field: a.<|>
-                    });
-                }
-                ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "another_field",
-                source_range: 328..328,
-                delete: 328..328,
-                insert: "another_field",
-                kind: Field,
-                detail: "i64",
-            },
-            CompletionItem {
-                label: "another_good_type",
-                source_range: 328..328,
-                delete: 328..328,
-                insert: "another_good_type",
-                kind: Field,
-                detail: "u32",
-                score: TypeMatch,
-            },
-            CompletionItem {
-                label: "the_field",
-                source_range: 328..328,
-                delete: 328..328,
-                insert: "the_field",
-                kind: Field,
-                detail: "u32",
-                score: TypeAndNameMatch,
-            },
-        ]
-        "###
+    fn prioritize_exact_ref_match() {
+        check_scores(
+            r#"
+struct WorldSnapshot { _f: () };
+fn go(world: &WorldSnapshot) { go(w<|>) }
+"#,
+            expect![[r#"
+                bn world [type+name]
+                st WorldSnapshot []
+                fn go(…) []
+            "#]],
         );
     }
 
     #[test]
-    fn prioritize_exact_ref_match() {
-        assert_debug_snapshot!(
-        do_reference_completion(
-                r"
-                    struct WorldSnapshot { _f: () };
-                    fn go(world: &WorldSnapshot) {
-                        go(w<|>)
-                    }
-                    ",
-        ),
-            @r###"
-        [
-            CompletionItem {
-                label: "WorldSnapshot",
-                source_range: 132..133,
-                delete: 132..133,
-                insert: "WorldSnapshot",
-                kind: Struct,
-            },
-            CompletionItem {
-                label: "go(…)",
-                source_range: 132..133,
-                delete: 132..133,
-                insert: "go(${1:world})$0",
-                kind: Function,
-                lookup: "go",
-                detail: "fn go(world: &WorldSnapshot)",
-                trigger_call_info: true,
-            },
-            CompletionItem {
-                label: "world",
-                source_range: 132..133,
-                delete: 132..133,
-                insert: "world",
-                kind: Binding,
-                detail: "&WorldSnapshot",
-                score: TypeAndNameMatch,
-            },
-        ]
-        "###
+    fn guesses_macro_braces() {
+        check_edit(
+            "vec!",
+            r#"
+/// Creates a [`Vec`] containing the arguments.
+///
+/// ```
+/// let v = vec![1, 2, 3];
+/// assert_eq!(v[0], 1);
+/// assert_eq!(v[1], 2);
+/// assert_eq!(v[2], 3);
+/// ```
+macro_rules! vec { () => {} }
+
+fn fn main() { v<|> }
+"#,
+            r#"
+/// Creates a [`Vec`] containing the arguments.
+///
+/// ```
+/// let v = vec![1, 2, 3];
+/// assert_eq!(v[0], 1);
+/// assert_eq!(v[1], 2);
+/// assert_eq!(v[2], 3);
+/// ```
+macro_rules! vec { () => {} }
+
+fn fn main() { vec![$0] }
+"#,
         );
+
+        check_edit(
+            "foo!",
+            r#"
+/// Foo
+///
+/// Don't call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`,
+/// call as `let _=foo!  { hello world };`
+macro_rules! foo { () => {} }
+fn main() { <|> }
+"#,
+            r#"
+/// Foo
+///
+/// Don't call `fooo!()` `fooo!()`, or `_foo![]` `_foo![]`,
+/// call as `let _=foo!  { hello world };`
+macro_rules! foo { () => {} }
+fn main() { foo! {$0} }
+"#,
+        )
     }
 }
diff --git a/crates/ra_ide/src/completion/test_utils.rs b/crates/ra_ide/src/completion/test_utils.rs
index bf22452a2..919177745 100644
--- a/crates/ra_ide/src/completion/test_utils.rs
+++ b/crates/ra_ide/src/completion/test_utils.rs
@@ -1,29 +1,114 @@
 //! Runs completion for testing purposes.
 
+use hir::Semantics;
+use itertools::Itertools;
+use ra_syntax::{AstNode, NodeOrToken, SyntaxElement};
+use stdx::{format_to, trim_indent};
+use test_utils::assert_eq_text;
+
 use crate::{
     completion::{completion_item::CompletionKind, CompletionConfig},
-    mock_analysis::{analysis_and_position, single_file_with_position},
+    mock_analysis::analysis_and_position,
     CompletionItem,
 };
 
 pub(crate) fn do_completion(code: &str, kind: CompletionKind) -> Vec<CompletionItem> {
-    do_completion_with_options(code, kind, &CompletionConfig::default())
+    do_completion_with_config(CompletionConfig::default(), code, kind)
 }
 
-pub(crate) fn do_completion_with_options(
+pub(crate) fn do_completion_with_config(
+    config: CompletionConfig,
     code: &str,
     kind: CompletionKind,
-    options: &CompletionConfig,
 ) -> Vec<CompletionItem> {
-    let (analysis, position) = if code.contains("//-") {
-        analysis_and_position(code)
-    } else {
-        single_file_with_position(code)
-    };
-    let completions = analysis.completions(options, position).unwrap().unwrap();
-    let completion_items: Vec<CompletionItem> = completions.into();
-    let mut kind_completions: Vec<CompletionItem> =
-        completion_items.into_iter().filter(|c| c.completion_kind == kind).collect();
+    let mut kind_completions: Vec<CompletionItem> = get_all_completion_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .collect();
+    kind_completions.sort_by(|l, r| l.label().cmp(r.label()));
+    kind_completions
+}
+
+pub(crate) fn completion_list(code: &str, kind: CompletionKind) -> String {
+    completion_list_with_config(CompletionConfig::default(), code, kind)
+}
+
+pub(crate) fn completion_list_with_config(
+    config: CompletionConfig,
+    code: &str,
+    kind: CompletionKind,
+) -> String {
+    let mut kind_completions: Vec<CompletionItem> = get_all_completion_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .collect();
     kind_completions.sort_by_key(|c| c.label().to_owned());
+    let label_width = kind_completions
+        .iter()
+        .map(|it| monospace_width(it.label()))
+        .max()
+        .unwrap_or_default()
+        .min(16);
     kind_completions
+        .into_iter()
+        .map(|it| {
+            let tag = it.kind().unwrap().tag();
+            let var_name = format!("{} {}", tag, it.label());
+            let mut buf = var_name;
+            if let Some(detail) = it.detail() {
+                let width = label_width.saturating_sub(monospace_width(it.label()));
+                format_to!(buf, "{:width$} {}", "", detail, width = width);
+            }
+            format_to!(buf, "\n");
+            buf
+        })
+        .collect()
+}
+
+fn monospace_width(s: &str) -> usize {
+    s.chars().count()
+}
+
+pub(crate) fn check_edit(what: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+    check_edit_with_config(CompletionConfig::default(), what, ra_fixture_before, ra_fixture_after)
+}
+
+pub(crate) fn check_edit_with_config(
+    config: CompletionConfig,
+    what: &str,
+    ra_fixture_before: &str,
+    ra_fixture_after: &str,
+) {
+    let ra_fixture_after = trim_indent(ra_fixture_after);
+    let (analysis, position) = analysis_and_position(ra_fixture_before);
+    let completions: Vec<CompletionItem> =
+        analysis.completions(&config, position).unwrap().unwrap().into();
+    let (completion,) = completions
+        .iter()
+        .filter(|it| it.lookup() == what)
+        .collect_tuple()
+        .unwrap_or_else(|| panic!("can't find {:?} completion in {:#?}", what, completions));
+    let mut actual = analysis.file_text(position.file_id).unwrap().to_string();
+    completion.text_edit().apply(&mut actual);
+    assert_eq_text!(&ra_fixture_after, &actual)
+}
+
+pub(crate) fn check_pattern_is_applicable(code: &str, check: fn(SyntaxElement) -> bool) {
+    let (analysis, pos) = analysis_and_position(code);
+    analysis
+        .with_db(|db| {
+            let sema = Semantics::new(db);
+            let original_file = sema.parse(pos.file_id);
+            let token = original_file.syntax().token_at_offset(pos.offset).left_biased().unwrap();
+            assert!(check(NodeOrToken::Token(token)));
+        })
+        .unwrap();
+}
+
+pub(crate) fn get_all_completion_items(
+    config: CompletionConfig,
+    code: &str,
+) -> Vec<CompletionItem> {
+    let (analysis, position) = analysis_and_position(code);
+    analysis.completions(&config, position).unwrap().unwrap().into()
 }
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 15dc50cf1..fe75f4b2c 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -8,20 +8,20 @@ use std::cell::RefCell;
 
 use hir::{
     diagnostics::{AstDiagnostic, Diagnostic as _, DiagnosticSink},
-    Semantics,
+    HasSource, HirDisplay, Semantics, VariantDef,
 };
 use itertools::Itertools;
-use ra_db::{RelativePath, SourceDatabase, SourceDatabaseExt};
+use ra_db::SourceDatabase;
 use ra_ide_db::RootDatabase;
 use ra_prof::profile;
 use ra_syntax::{
     algo,
-    ast::{self, make, AstNode},
+    ast::{self, edit::IndentLevel, make, AstNode},
     SyntaxNode, TextRange, T,
 };
 use ra_text_edit::{TextEdit, TextEditBuilder};
 
-use crate::{Diagnostic, FileId, FileSystemEdit, Fix, SourceChange, SourceFileEdit};
+use crate::{Diagnostic, FileId, FileSystemEdit, Fix, SourceFileEdit};
 
 #[derive(Debug, Copy, Clone)]
 pub enum Severity {
@@ -35,7 +35,8 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     let parse = db.parse(file_id);
     let mut res = Vec::new();
 
-    res.extend(parse.errors().iter().map(|err| Diagnostic {
+    // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
+    res.extend(parse.errors().iter().take(128).map(|err| Diagnostic {
         range: err.range(),
         message: format!("Syntax Error: {}", err),
         severity: Severity::Error,
@@ -57,14 +58,10 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     })
     .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
         let original_file = d.source().file_id.original_file(db);
-        let source_root = db.file_source_root(original_file);
-        let path = db
-            .file_relative_path(original_file)
-            .parent()
-            .unwrap_or_else(|| RelativePath::new(""))
-            .join(&d.candidate);
-        let fix =
-            Fix::new("Create module", FileSystemEdit::CreateFile { source_root, path }.into());
+        let fix = Fix::new(
+            "Create module",
+            FileSystemEdit::CreateFile { anchor: original_file, dst: d.candidate.clone() }.into(),
+        );
         res.borrow_mut().push(Diagnostic {
             range: sema.diagnostics_range(d).range,
             message: d.message(),
@@ -103,19 +100,11 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
             fix,
         })
     })
-    .on::<hir::diagnostics::MissingMatchArms, _>(|d| {
-        res.borrow_mut().push(Diagnostic {
-            range: sema.diagnostics_range(d).range,
-            message: d.message(),
-            severity: Severity::Error,
-            fix: None,
-        })
-    })
     .on::<hir::diagnostics::MissingOkInTailExpr, _>(|d| {
         let node = d.ast(db);
         let replacement = format!("Ok({})", node.syntax());
         let edit = TextEdit::replace(node.syntax().text_range(), replacement);
-        let source_change = SourceChange::source_file_edit_from(file_id, edit);
+        let source_change = SourceFileEdit { file_id, edit }.into();
         let fix = Fix::new("Wrap with ok", source_change);
         res.borrow_mut().push(Diagnostic {
             range: sema.diagnostics_range(d).range,
@@ -123,7 +112,16 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
             severity: Severity::Error,
             fix: Some(fix),
         })
+    })
+    .on::<hir::diagnostics::NoSuchField, _>(|d| {
+        res.borrow_mut().push(Diagnostic {
+            range: sema.diagnostics_range(d).range,
+            message: d.message(),
+            severity: Severity::Error,
+            fix: missing_struct_field_fix(&sema, file_id, d),
+        })
     });
+
     if let Some(m) = sema.to_module_def(file_id) {
         m.diagnostics(db, &mut sink);
     };
@@ -131,6 +129,80 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     res.into_inner()
 }
 
+fn missing_struct_field_fix(
+    sema: &Semantics<RootDatabase>,
+    usage_file_id: FileId,
+    d: &hir::diagnostics::NoSuchField,
+) -> Option<Fix> {
+    let record_expr = sema.ast(d);
+
+    let record_lit = ast::RecordLit::cast(record_expr.syntax().parent()?.parent()?)?;
+    let def_id = sema.resolve_variant(record_lit)?;
+    let module;
+    let def_file_id;
+    let record_fields = match VariantDef::from(def_id) {
+        VariantDef::Struct(s) => {
+            module = s.module(sema.db);
+            let source = s.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_def_list()?;
+            record_field_def_list(fields)?
+        }
+        VariantDef::Union(u) => {
+            module = u.module(sema.db);
+            let source = u.source(sema.db);
+            def_file_id = source.file_id;
+            source.value.record_field_def_list()?
+        }
+        VariantDef::EnumVariant(e) => {
+            module = e.module(sema.db);
+            let source = e.source(sema.db);
+            def_file_id = source.file_id;
+            let fields = source.value.field_def_list()?;
+            record_field_def_list(fields)?
+        }
+    };
+    let def_file_id = def_file_id.original_file(sema.db);
+
+    let new_field_type = sema.type_of_expr(&record_expr.expr()?)?;
+    if new_field_type.is_unknown() {
+        return None;
+    }
+    let new_field = make::record_field_def(
+        record_expr.field_name()?,
+        make::type_ref(&new_field_type.display_source_code(sema.db, module.into()).ok()?),
+    );
+
+    let last_field = record_fields.fields().last()?;
+    let last_field_syntax = last_field.syntax();
+    let indent = IndentLevel::from_node(last_field_syntax);
+
+    let mut new_field = new_field.to_string();
+    if usage_file_id != def_file_id {
+        new_field = format!("pub(crate) {}", new_field);
+    }
+    new_field = format!("\n{}{}", indent, new_field);
+
+    let needs_comma = !last_field_syntax.to_string().ends_with(",");
+    if needs_comma {
+        new_field = format!(",{}", new_field);
+    }
+
+    let source_change = SourceFileEdit {
+        file_id: def_file_id,
+        edit: TextEdit::insert(last_field_syntax.text_range().end(), new_field),
+    };
+    let fix = Fix::new("Create field", source_change.into());
+    return Some(fix);
+
+    fn record_field_def_list(field_def_list: ast::FieldDefList) -> Option<ast::RecordFieldDefList> {
+        match field_def_list {
+            ast::FieldDefList::RecordFieldDefList(it) => Some(it),
+            ast::FieldDefList::TupleFieldDefList(_) => None,
+        }
+    }
+}
+
 fn check_unnecessary_braces_in_use_statement(
     acc: &mut Vec<Diagnostic>,
     file_id: FileId,
@@ -187,7 +259,8 @@ fn check_struct_shorthand_initialization(
         if let (Some(name_ref), Some(expr)) = (record_field.name_ref(), record_field.expr()) {
             let field_name = name_ref.syntax().text().to_string();
             let field_expr = expr.syntax().text().to_string();
-            if field_name == field_expr {
+            let field_name_is_tup_index = name_ref.as_tuple_field().is_some();
+            if field_name == field_expr && !field_name_is_tup_index {
                 let mut edit_builder = TextEditBuilder::default();
                 edit_builder.delete(record_field.syntax().text_range());
                 edit_builder.insert(record_field.syntax().text_range().start(), field_name);
@@ -210,51 +283,21 @@ fn check_struct_shorthand_initialization(
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
-    use ra_syntax::SourceFile;
-    use stdx::SepBy;
+    use stdx::trim_indent;
     use test_utils::assert_eq_text;
 
-    use crate::mock_analysis::{analysis_and_position, single_file};
-
-    use super::*;
-
-    type DiagnosticChecker = fn(&mut Vec<Diagnostic>, FileId, &SyntaxNode) -> Option<()>;
-
-    fn check_not_applicable(code: &str, func: DiagnosticChecker) {
-        let parse = SourceFile::parse(code);
-        let mut diagnostics = Vec::new();
-        for node in parse.tree().syntax().descendants() {
-            func(&mut diagnostics, FileId(0), &node);
-        }
-        assert!(diagnostics.is_empty());
-    }
-
-    fn check_apply(before: &str, after: &str, func: DiagnosticChecker) {
-        let parse = SourceFile::parse(before);
-        let mut diagnostics = Vec::new();
-        for node in parse.tree().syntax().descendants() {
-            func(&mut diagnostics, FileId(0), &node);
-        }
-        let diagnostic =
-            diagnostics.pop().unwrap_or_else(|| panic!("no diagnostics for:\n{}\n", before));
-        let mut fix = diagnostic.fix.unwrap();
-        let edit = fix.source_change.source_file_edits.pop().unwrap().edit;
-        let actual = {
-            let mut actual = before.to_string();
-            edit.apply(&mut actual);
-            actual
-        };
-        assert_eq_text!(after, &actual);
-    }
+    use crate::mock_analysis::{analysis_and_position, single_file, MockAnalysis};
+    use expect::{expect, Expect};
 
     /// Takes a multi-file input fixture with annotated cursor positions,
     /// and checks that:
     ///  * a diagnostic is produced
     ///  * this diagnostic touches the input cursor position
     ///  * that the contents of the file containing the cursor match `after` after the diagnostic fix is applied
-    fn check_apply_diagnostic_fix_from_position(fixture: &str, after: &str) {
-        let (analysis, file_position) = analysis_and_position(fixture);
+    fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let after = trim_indent(ra_fixture_after);
+
+        let (analysis, file_position) = analysis_and_position(ra_fixture_before);
         let diagnostic = analysis.diagnostics(file_position.file_id).unwrap().pop().unwrap();
         let mut fix = diagnostic.fix.unwrap();
         let edit = fix.source_change.source_file_edits.pop().unwrap().edit;
@@ -265,21 +308,6 @@ mod tests {
             actual
         };
 
-        // Strip indent and empty lines from `after`, to match the behaviour of
-        // `parse_fixture` called from `analysis_and_position`.
-        let margin = fixture
-            .lines()
-            .filter(|it| it.trim_start().starts_with("//-"))
-            .map(|it| it.len() - it.trim_start().len())
-            .next()
-            .expect("empty fixture");
-        let after = after
-            .lines()
-            .filter_map(|line| if line.len() > margin { Some(&line[margin..]) } else { None })
-            .sep_by("\n")
-            .suffix("\n")
-            .to_string();
-
         assert_eq_text!(&after, &actual);
         assert!(
             diagnostic.range.start() <= file_position.offset
@@ -290,508 +318,470 @@ mod tests {
         );
     }
 
-    fn check_apply_diagnostic_fix(before: &str, after: &str) {
-        let (analysis, file_id) = single_file(before);
-        let diagnostic = analysis.diagnostics(file_id).unwrap().pop().unwrap();
+    /// Checks that a diagnostic applies to the file containing the `<|>` cursor marker
+    /// which has a fix that can apply to other files.
+    fn check_apply_diagnostic_fix_in_other_file(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let (analysis, file_pos) = analysis_and_position(ra_fixture_before);
+        let current_file_id = file_pos.file_id;
+        let diagnostic = analysis.diagnostics(current_file_id).unwrap().pop().unwrap();
         let mut fix = diagnostic.fix.unwrap();
-        let edit = fix.source_change.source_file_edits.pop().unwrap().edit;
+        let edit = fix.source_change.source_file_edits.pop().unwrap();
+        let changed_file_id = edit.file_id;
+        let before = analysis.file_text(changed_file_id).unwrap();
         let actual = {
             let mut actual = before.to_string();
-            edit.apply(&mut actual);
+            edit.edit.apply(&mut actual);
             actual
         };
-        assert_eq_text!(after, &actual);
+        assert_eq_text!(ra_fixture_after, &actual);
     }
 
     /// Takes a multi-file input fixture with annotated cursor position and checks that no diagnostics
     /// apply to the file containing the cursor.
-    fn check_no_diagnostic_for_target_file(fixture: &str) {
-        let (analysis, file_position) = analysis_and_position(fixture);
-        let diagnostics = analysis.diagnostics(file_position.file_id).unwrap();
-        assert_eq!(diagnostics.len(), 0);
+    fn check_no_diagnostics(ra_fixture: &str) {
+        let mock = MockAnalysis::with_files(ra_fixture);
+        let files = mock.files().map(|(it, _)| it).collect::<Vec<_>>();
+        let analysis = mock.analysis();
+        let diagnostics = files
+            .into_iter()
+            .flat_map(|file_id| analysis.diagnostics(file_id).unwrap())
+            .collect::<Vec<_>>();
+        assert_eq!(diagnostics.len(), 0, "unexpected diagnostics:\n{:#?}", diagnostics);
     }
 
-    fn check_no_diagnostic(content: &str) {
-        let (analysis, file_id) = single_file(content);
+    fn check_expect(ra_fixture: &str, expect: Expect) {
+        let (analysis, file_id) = single_file(ra_fixture);
         let diagnostics = analysis.diagnostics(file_id).unwrap();
-        assert_eq!(diagnostics.len(), 0, "expected no diagnostic, found one");
+        expect.assert_debug_eq(&diagnostics)
     }
 
     #[test]
     fn test_wrap_return_type() {
-        let before = r#"
-            //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
 
-            fn div(x: i32, y: i32) -> Result<i32, String> {
-                if y == 0 {
-                    return Err("div by zero".into());
-                }
-                x / y<|>
-            }
+fn div(x: i32, y: i32) -> Result<i32, ()> {
+    if y == 0 {
+        return Err(());
+    }
+    x / y<|>
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
-            pub mod result {
-                pub enum Result<T, E> { Ok(T), Err(E) }
-            }
-        "#;
-        let after = r#"
-            use std::{string::String, result::Result::{self, Ok, Err}};
-
-            fn div(x: i32, y: i32) -> Result<i32, String> {
-                if y == 0 {
-                    return Err("div by zero".into());
-                }
-                Ok(x / y)
-            }
-        "#;
-        check_apply_diagnostic_fix_from_position(before, after);
+fn div(x: i32, y: i32) -> Result<i32, ()> {
+    if y == 0 {
+        return Err(());
+    }
+    Ok(x / y)
+}
+"#,
+        );
     }
 
     #[test]
     fn test_wrap_return_type_handles_generic_functions() {
-        let before = r#"
-            //- /main.rs
-            use std::result::Result::{self, Ok, Err};
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
 
-            fn div<T>(x: T) -> Result<T, i32> {
-                if x == 0 {
-                    return Err(7);
-                }
-                <|>x
-            }
+fn div<T>(x: T) -> Result<T, i32> {
+    if x == 0 {
+        return Err(7);
+    }
+    <|>x
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
 
-            //- /std/lib.rs
-            pub mod result {
-                pub enum Result<T, E> { Ok(T), Err(E) }
-            }
-        "#;
-        let after = r#"
-            use std::result::Result::{self, Ok, Err};
-
-            fn div<T>(x: T) -> Result<T, i32> {
-                if x == 0 {
-                    return Err(7);
-                }
-                Ok(x)
-            }
-        "#;
-        check_apply_diagnostic_fix_from_position(before, after);
+fn div<T>(x: T) -> Result<T, i32> {
+    if x == 0 {
+        return Err(7);
+    }
+    Ok(x)
+}
+"#,
+        );
     }
 
     #[test]
     fn test_wrap_return_type_handles_type_aliases() {
-        let before = r#"
-            //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+        check_fix(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
 
-            type MyResult<T> = Result<T, String>;
+type MyResult<T> = Result<T, ()>;
 
-            fn div(x: i32, y: i32) -> MyResult<i32> {
-                if y == 0 {
-                    return Err("div by zero".into());
-                }
-                x <|>/ y
-            }
+fn div(x: i32, y: i32) -> MyResult<i32> {
+    if y == 0 {
+        return Err(());
+    }
+    x <|>/ y
+}
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+            r#"
+use core::result::Result::{self, Ok, Err};
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
-            pub mod result {
-                pub enum Result<T, E> { Ok(T), Err(E) }
-            }
-        "#;
-        let after = r#"
-            use std::{string::String, result::Result::{self, Ok, Err}};
-
-            type MyResult<T> = Result<T, String>;
-            fn div(x: i32, y: i32) -> MyResult<i32> {
-                if y == 0 {
-                    return Err("div by zero".into());
-                }
-                Ok(x / y)
-            }
-        "#;
-        check_apply_diagnostic_fix_from_position(before, after);
+type MyResult<T> = Result<T, ()>;
+
+fn div(x: i32, y: i32) -> MyResult<i32> {
+    if y == 0 {
+        return Err(());
+    }
+    Ok(x / y)
+}
+"#,
+        );
     }
 
     #[test]
     fn test_wrap_return_type_not_applicable_when_expr_type_does_not_match_ok_type() {
-        let content = r#"
-            //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+        check_no_diagnostics(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
 
-            fn foo() -> Result<String, i32> {
-                0<|>
-            }
+fn foo() -> Result<(), i32> { 0 }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
-            pub mod result {
-                pub enum Result<T, E> { Ok(T), Err(E) }
-            }
-        "#;
-        check_no_diagnostic_for_target_file(content);
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+        );
     }
 
     #[test]
     fn test_wrap_return_type_not_applicable_when_return_type_is_not_result() {
-        let content = r#"
-            //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+        check_no_diagnostics(
+            r#"
+//- /main.rs
+use core::result::Result::{self, Ok, Err};
 
-            enum SomeOtherEnum {
-                Ok(i32),
-                Err(String),
-            }
+enum SomeOtherEnum { Ok(i32), Err(String) }
 
-            fn foo() -> SomeOtherEnum {
-                0<|>
-            }
+fn foo() -> SomeOtherEnum { 0 }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
-            pub mod result {
-                pub enum Result<T, E> { Ok(T), Err(E) }
-            }
-        "#;
-        check_no_diagnostic_for_target_file(content);
+//- /core/lib.rs
+pub mod result {
+    pub enum Result<T, E> { Ok(T), Err(E) }
+}
+"#,
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_empty() {
-        let before = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+        check_fix(
+            r#"
+struct TestStruct { one: i32, two: i64 }
 
-            fn test_fn() {
-                let s = TestStruct{};
-            }
-        ";
-        let after = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+fn test_fn() {
+    let s = TestStruct {<|>};
+}
+"#,
+            r#"
+struct TestStruct { one: i32, two: i64 }
 
-            fn test_fn() {
-                let s = TestStruct{ one: (), two: ()};
-            }
-        ";
-        check_apply_diagnostic_fix(before, after);
+fn test_fn() {
+    let s = TestStruct { one: (), two: ()};
+}
+"#,
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_self() {
-        let before = r"
-            struct TestStruct {
-                one: i32,
-            }
+        check_fix(
+            r#"
+struct TestStruct { one: i32 }
 
-            impl TestStruct {
-                fn test_fn() {
-                    let s = Self {};
-                }
-            }
-        ";
-        let after = r"
-            struct TestStruct {
-                one: i32,
-            }
+impl TestStruct {
+    fn test_fn() { let s = Self {<|>}; }
+}
+"#,
+            r#"
+struct TestStruct { one: i32 }
 
-            impl TestStruct {
-                fn test_fn() {
-                    let s = Self { one: ()};
-                }
-            }
-        ";
-        check_apply_diagnostic_fix(before, after);
+impl TestStruct {
+    fn test_fn() { let s = Self { one: ()}; }
+}
+"#,
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_enum() {
-        let before = r"
-            enum Expr {
-                Bin { lhs: Box<Expr>, rhs: Box<Expr> }
-            }
-
-            impl Expr {
-                fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
-                    Expr::Bin { <|> }
-                }
-            }
-
-        ";
-        let after = r"
-            enum Expr {
-                Bin { lhs: Box<Expr>, rhs: Box<Expr> }
-            }
+        check_fix(
+            r#"
+enum Expr {
+    Bin { lhs: Box<Expr>, rhs: Box<Expr> }
+}
 
-            impl Expr {
-                fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
-                    Expr::Bin { lhs: (), rhs: () <|> }
-                }
-            }
+impl Expr {
+    fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
+        Expr::Bin {<|> }
+    }
+}
+"#,
+            r#"
+enum Expr {
+    Bin { lhs: Box<Expr>, rhs: Box<Expr> }
+}
 
-        ";
-        check_apply_diagnostic_fix(before, after);
+impl Expr {
+    fn new_bin(lhs: Box<Expr>, rhs: Box<Expr>) -> Expr {
+        Expr::Bin { lhs: (), rhs: () }
+    }
+}
+"#,
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_partial() {
-        let before = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+        check_fix(
+            r#"
+struct TestStruct { one: i32, two: i64 }
 
-            fn test_fn() {
-                let s = TestStruct{ two: 2 };
-            }
-        ";
-        let after = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+fn test_fn() {
+    let s = TestStruct{ two: 2<|> };
+}
+"#,
+            r"
+struct TestStruct { one: i32, two: i64 }
 
-            fn test_fn() {
-                let s = TestStruct{ two: 2, one: () };
-            }
-        ";
-        check_apply_diagnostic_fix(before, after);
+fn test_fn() {
+    let s = TestStruct{ two: 2, one: () };
+}
+",
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_no_diagnostic() {
-        let content = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+        check_no_diagnostics(
+            r"
+            struct TestStruct { one: i32, two: i64 }
 
             fn test_fn() {
                 let one = 1;
                 let s = TestStruct{ one, two: 2 };
             }
-        ";
-
-        check_no_diagnostic(content);
+        ",
+        );
     }
 
     #[test]
     fn test_fill_struct_fields_no_diagnostic_on_spread() {
-        let content = r"
-            struct TestStruct {
-                one: i32,
-                two: i64,
-            }
+        check_no_diagnostics(
+            r"
+            struct TestStruct { one: i32, two: i64 }
 
             fn test_fn() {
                 let one = 1;
                 let s = TestStruct{ ..a };
             }
-        ";
-
-        check_no_diagnostic(content);
+        ",
+        );
     }
 
     #[test]
     fn test_unresolved_module_diagnostic() {
-        let (analysis, file_id) = single_file("mod foo;");
-        let diagnostics = analysis.diagnostics(file_id).unwrap();
-        assert_debug_snapshot!(diagnostics, @r###"
-        [
-            Diagnostic {
-                message: "unresolved module",
-                range: 0..8,
-                severity: Error,
-                fix: Some(
-                    Fix {
-                        label: "Create module",
-                        source_change: SourceChange {
-                            source_file_edits: [],
-                            file_system_edits: [
-                                CreateFile {
-                                    source_root: SourceRootId(
-                                        0,
-                                    ),
-                                    path: "foo.rs",
+        check_expect(
+            r#"mod foo;"#,
+            expect![[r#"
+                [
+                    Diagnostic {
+                        message: "unresolved module",
+                        range: 0..8,
+                        severity: Error,
+                        fix: Some(
+                            Fix {
+                                label: "Create module",
+                                source_change: SourceChange {
+                                    source_file_edits: [],
+                                    file_system_edits: [
+                                        CreateFile {
+                                            anchor: FileId(
+                                                1,
+                                            ),
+                                            dst: "foo.rs",
+                                        },
+                                    ],
+                                    is_snippet: false,
                                 },
-                            ],
-                            is_snippet: false,
-                        },
+                            },
+                        ),
                     },
-                ),
-            },
-        ]
-        "###);
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn range_mapping_out_of_macros() {
-        let (analysis, file_id) = single_file(
-            r"
-            fn some() {}
-            fn items() {}
-            fn here() {}
+        // FIXME: this is very wrong, but somewhat tricky to fix.
+        check_fix(
+            r#"
+fn some() {}
+fn items() {}
+fn here() {}
 
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)*};
-            }
+macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
 
-            fn main() {
-                let _x = id![Foo { a: 42 }];
-            }
+fn main() {
+    let _x = id![Foo { a: <|>42 }];
+}
 
-            pub struct Foo {
-                pub a: i32,
-                pub b: i32,
-            }
-        ",
+pub struct Foo { pub a: i32, pub b: i32 }
+"#,
+            r#"
+fn {a:42, b: ()} {}
+fn items() {}
+fn here() {}
+
+macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
+
+fn main() {
+    let _x = id![Foo { a: 42 }];
+}
+
+pub struct Foo { pub a: i32, pub b: i32 }
+"#,
         );
-        let diagnostics = analysis.diagnostics(file_id).unwrap();
-        assert_debug_snapshot!(diagnostics, @r###"
-        [
-            Diagnostic {
-                message: "Missing structure fields:\n- b\n",
-                range: 224..233,
-                severity: Error,
-                fix: Some(
-                    Fix {
-                        label: "Fill struct fields",
-                        source_change: SourceChange {
-                            source_file_edits: [
-                                SourceFileEdit {
-                                    file_id: FileId(
-                                        1,
-                                    ),
-                                    edit: TextEdit {
-                                        indels: [
-                                            Indel {
-                                                insert: "{a:42, b: ()}",
-                                                delete: 3..9,
-                                            },
-                                        ],
-                                    },
-                                },
-                            ],
-                            file_system_edits: [],
-                            is_snippet: false,
-                        },
-                    },
-                ),
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn test_check_unnecessary_braces_in_use_statement() {
-        check_not_applicable(
-            "
-            use a;
-            use a::{c, d::e};
-        ",
-            check_unnecessary_braces_in_use_statement,
-        );
-        check_apply("use {b};", "use b;", check_unnecessary_braces_in_use_statement);
-        check_apply("use a::{c};", "use a::c;", check_unnecessary_braces_in_use_statement);
-        check_apply("use a::{self};", "use a;", check_unnecessary_braces_in_use_statement);
-        check_apply(
-            "use a::{c, d::{e}};",
-            "use a::{c, d::e};",
-            check_unnecessary_braces_in_use_statement,
+        check_no_diagnostics(
+            r#"
+use a;
+use a::{c, d::e};
+"#,
         );
+        check_fix(r#"use {<|>b};"#, r#"use b;"#);
+        check_fix(r#"use {b<|>};"#, r#"use b;"#);
+        check_fix(r#"use a::{c<|>};"#, r#"use a::c;"#);
+        check_fix(r#"use a::{self<|>};"#, r#"use a;"#);
+        check_fix(r#"use a::{c, d::{e<|>}};"#, r#"use a::{c, d::e};"#);
     }
 
     #[test]
     fn test_check_struct_shorthand_initialization() {
-        check_not_applicable(
+        check_no_diagnostics(
             r#"
-            struct A {
-                a: &'static str
-            }
-
-            fn main() {
-                A {
-                    a: "hello"
-                }
-            }
-        "#,
-            check_struct_shorthand_initialization,
+struct A { a: &'static str }
+fn main() { A { a: "hello" } }
+"#,
         );
-
-        check_apply(
+        check_no_diagnostics(
             r#"
-struct A {
-    a: &'static str
-}
+struct A(usize);
+fn main() { A { 0: 0 } }
+"#,
+        );
 
+        check_fix(
+            r#"
+struct A { a: &'static str }
 fn main() {
     let a = "haha";
-    A {
-        a: a
-    }
+    A { a<|>: a }
 }
-        "#,
+"#,
             r#"
-struct A {
-    a: &'static str
-}
-
+struct A { a: &'static str }
 fn main() {
     let a = "haha";
-    A {
-        a
-    }
+    A { a }
 }
-        "#,
-            check_struct_shorthand_initialization,
+"#,
         );
 
-        check_apply(
+        check_fix(
             r#"
-struct A {
-    a: &'static str,
-    b: &'static str
-}
-
+struct A { a: &'static str, b: &'static str }
 fn main() {
     let a = "haha";
     let b = "bb";
-    A {
-        a: a,
-        b
-    }
+    A { a<|>: a, b }
 }
-        "#,
+"#,
             r#"
-struct A {
-    a: &'static str,
-    b: &'static str
-}
-
+struct A { a: &'static str, b: &'static str }
 fn main() {
     let a = "haha";
     let b = "bb";
-    A {
-        a,
-        b
-    }
+    A { a, b }
 }
-        "#,
-            check_struct_shorthand_initialization,
+"#,
         );
     }
+
+    #[test]
+    fn test_add_field_from_usage() {
+        check_fix(
+            r"
+fn main() {
+    Foo { bar: 3, baz<|>: false};
+}
+struct Foo {
+    bar: i32
+}
+",
+            r"
+fn main() {
+    Foo { bar: 3, baz: false};
+}
+struct Foo {
+    bar: i32,
+    baz: bool
+}
+",
+        )
+    }
+
+    #[test]
+    fn test_add_field_in_other_file_from_usage() {
+        check_apply_diagnostic_fix_in_other_file(
+            r"
+            //- /main.rs
+            mod foo;
+
+            fn main() {
+                <|>foo::Foo { bar: 3, baz: false};
+            }
+            //- /foo.rs
+            struct Foo {
+                bar: i32
+            }
+            ",
+            r"
+            struct Foo {
+                bar: i32,
+                pub(crate) baz: bool
+            }
+            ",
+        )
+    }
 }
diff --git a/crates/ra_ide/src/display.rs b/crates/ra_ide/src/display.rs
index 827c094e7..70d2a2dd1 100644
--- a/crates/ra_ide/src/display.rs
+++ b/crates/ra_ide/src/display.rs
@@ -6,13 +6,10 @@ mod navigation_target;
 mod structure;
 mod short_label;
 
-use std::fmt::Display;
-
 use ra_syntax::{
     ast::{self, AstNode, AttrsOwner, NameOwner, TypeParamsOwner},
     SyntaxKind::{ATTR, COMMENT},
 };
-use stdx::format_to;
 
 pub use function_signature::FunctionSignature;
 pub use navigation_target::NavigationTarget;
@@ -69,29 +66,3 @@ pub(crate) fn macro_label(node: &ast::MacroCall) -> String {
     let vis = if node.has_atom_attr("macro_export") { "#[macro_export]\n" } else { "" };
     format!("{}macro_rules! {}", vis, name)
 }
-
-pub(crate) fn rust_code_markup(code: &impl Display) -> String {
-    rust_code_markup_with_doc(code, None, None)
-}
-
-pub(crate) fn rust_code_markup_with_doc(
-    code: &impl Display,
-    doc: Option<&str>,
-    mod_path: Option<&str>,
-) -> String {
-    let mut buf = String::new();
-
-    if let Some(mod_path) = mod_path {
-        if !mod_path.is_empty() {
-            format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
-        }
-    }
-    format_to!(buf, "```rust\n{}\n```", code);
-
-    if let Some(doc) = doc {
-        format_to!(buf, "\n___");
-        format_to!(buf, "\n\n{}", doc);
-    }
-
-    buf
-}
diff --git a/crates/ra_ide/src/display/function_signature.rs b/crates/ra_ide/src/display/function_signature.rs
index 9572debd8..1d39544d3 100644
--- a/crates/ra_ide/src/display/function_signature.rs
+++ b/crates/ra_ide/src/display/function_signature.rs
@@ -10,7 +10,7 @@ use std::{
 use hir::{Docs, Documentation, HasSource, HirDisplay};
 use ra_ide_db::RootDatabase;
 use ra_syntax::ast::{self, AstNode, NameOwner, VisibilityOwner};
-use stdx::SepBy;
+use stdx::{split_delim, SepBy};
 
 use crate::display::{generic_parameters, where_predicates};
 
@@ -61,15 +61,11 @@ pub struct FunctionQualifier {
 }
 
 impl FunctionSignature {
-    pub(crate) fn with_doc_opt(mut self, doc: Option<Documentation>) -> Self {
-        self.doc = doc;
-        self
-    }
-
     pub(crate) fn from_hir(db: &RootDatabase, function: hir::Function) -> Self {
-        let doc = function.docs(db);
         let ast_node = function.source(db).value;
-        FunctionSignature::from(&ast_node).with_doc_opt(doc)
+        let mut res = FunctionSignature::from(&ast_node);
+        res.doc = function.docs(db);
+        res
     }
 
     pub(crate) fn from_struct(db: &RootDatabase, st: hir::Struct) -> Option<Self> {
@@ -93,24 +89,21 @@ impl FunctionSignature {
             params.push(raw_param);
         }
 
-        Some(
-            FunctionSignature {
-                kind: CallableKind::StructConstructor,
-                visibility: node.visibility().map(|n| n.syntax().text().to_string()),
-                // Do we need `const`?
-                qualifier: Default::default(),
-                name: node.name().map(|n| n.text().to_string()),
-                ret_type: node.name().map(|n| n.text().to_string()),
-                parameters: params,
-                parameter_names: vec![],
-                parameter_types,
-                generic_parameters: generic_parameters(&node),
-                where_predicates: where_predicates(&node),
-                doc: None,
-                has_self_param: false,
-            }
-            .with_doc_opt(st.docs(db)),
-        )
+        Some(FunctionSignature {
+            kind: CallableKind::StructConstructor,
+            visibility: node.visibility().map(|n| n.syntax().text().to_string()),
+            // Do we need `const`?
+            qualifier: Default::default(),
+            name: node.name().map(|n| n.text().to_string()),
+            ret_type: node.name().map(|n| n.text().to_string()),
+            parameters: params,
+            parameter_names: vec![],
+            parameter_types,
+            generic_parameters: generic_parameters(&node),
+            where_predicates: where_predicates(&node),
+            doc: st.docs(db),
+            has_self_param: false,
+        })
     }
 
     pub(crate) fn from_enum_variant(db: &RootDatabase, variant: hir::EnumVariant) -> Option<Self> {
@@ -140,24 +133,21 @@ impl FunctionSignature {
             params.push(format!("{}: {}", name, ty.display(db)));
         }
 
-        Some(
-            FunctionSignature {
-                kind: CallableKind::VariantConstructor,
-                visibility: None,
-                // Do we need `const`?
-                qualifier: Default::default(),
-                name: Some(name),
-                ret_type: None,
-                parameters: params,
-                parameter_names: vec![],
-                parameter_types,
-                generic_parameters: vec![],
-                where_predicates: vec![],
-                doc: None,
-                has_self_param: false,
-            }
-            .with_doc_opt(variant.docs(db)),
-        )
+        Some(FunctionSignature {
+            kind: CallableKind::VariantConstructor,
+            visibility: None,
+            // Do we need `const`?
+            qualifier: Default::default(),
+            name: Some(name),
+            ret_type: None,
+            parameters: params,
+            parameter_names: vec![],
+            parameter_types,
+            generic_parameters: vec![],
+            where_predicates: vec![],
+            doc: variant.docs(db),
+            has_self_param: false,
+        })
     }
 
     pub(crate) fn from_macro(db: &RootDatabase, macro_def: hir::MacroDef) -> Option<Self> {
@@ -165,23 +155,20 @@ impl FunctionSignature {
 
         let params = vec![];
 
-        Some(
-            FunctionSignature {
-                kind: CallableKind::Macro,
-                visibility: None,
-                qualifier: Default::default(),
-                name: node.name().map(|n| n.text().to_string()),
-                ret_type: None,
-                parameters: params,
-                parameter_names: vec![],
-                parameter_types: vec![],
-                generic_parameters: vec![],
-                where_predicates: vec![],
-                doc: None,
-                has_self_param: false,
-            }
-            .with_doc_opt(macro_def.docs(db)),
-        )
+        Some(FunctionSignature {
+            kind: CallableKind::Macro,
+            visibility: None,
+            qualifier: Default::default(),
+            name: node.name().map(|n| n.text().to_string()),
+            ret_type: None,
+            parameters: params,
+            parameter_names: vec![],
+            parameter_types: vec![],
+            generic_parameters: vec![],
+            where_predicates: vec![],
+            doc: macro_def.docs(db),
+            has_self_param: false,
+        })
     }
 }
 
@@ -207,7 +194,16 @@ impl From<&'_ ast::FnDef> for FunctionSignature {
                     res.push(raw_param);
                 }
 
-                res.extend(param_list.params().map(|param| param.syntax().text().to_string()));
+                // macro-generated functions are missing whitespace
+                fn fmt_param(param: ast::Param) -> String {
+                    let text = param.syntax().text().to_string();
+                    match split_delim(&text, ':') {
+                        Some((left, right)) => format!("{}: {}", left.trim(), right.trim()),
+                        _ => text,
+                    }
+                }
+
+                res.extend(param_list.params().map(fmt_param));
                 res_types.extend(param_list.params().map(|param| {
                     let param_text = param.syntax().text().to_string();
                     match param_text.split(':').nth(1).and_then(|it| it.get(1..)) {
diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index 5da28edd2..8bf2428ed 100644
--- a/crates/ra_ide/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
     TextRange,
 };
 
-use crate::{FileRange, FileSymbol};
+use crate::FileSymbol;
 
 use super::short_label::ShortLabel;
 
@@ -47,6 +47,19 @@ impl NavigationTarget {
     pub fn range(&self) -> TextRange {
         self.focus_range.unwrap_or(self.full_range)
     }
+    /// A "most interesting" range withing the `full_range`.
+    ///
+    /// Typically, `full_range` is the whole syntax node,
+    /// including doc comments, and `focus_range` is the range of the identifier.
+    pub fn focus_range(&self) -> Option<TextRange> {
+        self.focus_range
+    }
+    pub fn full_range(&self) -> TextRange {
+        self.full_range
+    }
+    pub fn file_id(&self) -> FileId {
+        self.file_id
+    }
 
     pub fn name(&self) -> &SmolStr {
         &self.name
@@ -60,18 +73,6 @@ impl NavigationTarget {
         self.kind
     }
 
-    pub fn file_id(&self) -> FileId {
-        self.file_id
-    }
-
-    pub fn file_range(&self) -> FileRange {
-        FileRange { file_id: self.file_id, range: self.full_range }
-    }
-
-    pub fn full_range(&self) -> TextRange {
-        self.full_range
-    }
-
     pub fn docs(&self) -> Option<&str> {
         self.docs.as_deref()
     }
@@ -80,27 +81,20 @@ impl NavigationTarget {
         self.description.as_deref()
     }
 
-    /// A "most interesting" range withing the `full_range`.
-    ///
-    /// Typically, `full_range` is the whole syntax node,
-    /// including doc comments, and `focus_range` is the range of the identifier.
-    pub fn focus_range(&self) -> Option<TextRange> {
-        self.focus_range
-    }
-
     pub(crate) fn from_module_to_decl(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
         let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
         if let Some(src) = module.declaration_source(db) {
             let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
-            return NavigationTarget::from_syntax(
+            let mut res = NavigationTarget::from_syntax(
                 frange.file_id,
                 name,
                 None,
                 frange.range,
                 src.value.syntax().kind(),
-                src.value.doc_comment_text(),
-                src.value.short_label(),
             );
+            res.docs = src.value.doc_comment_text();
+            res.description = src.value.short_label();
+            return res;
         }
         module.to_nav(db)
     }
@@ -130,14 +124,12 @@ impl NavigationTarget {
     }
 
     /// Allows `NavigationTarget` to be created from a `NameOwner`
-    fn from_named(
+    pub(crate) fn from_named(
         db: &RootDatabase,
         node: InFile<&dyn ast::NameOwner>,
-        docs: Option<String>,
-        description: Option<String>,
     ) -> NavigationTarget {
-        //FIXME: use `_` instead of empty string
-        let name = node.value.name().map(|it| it.text().clone()).unwrap_or_default();
+        let name =
+            node.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
         let focus_range =
             node.value.name().map(|it| original_range(db, node.with_value(it.syntax())).range);
         let frange = original_range(db, node.map(|it| it.syntax()));
@@ -148,8 +140,25 @@ impl NavigationTarget {
             focus_range,
             frange.range,
             node.value.syntax().kind(),
-            docs,
-            description,
+        )
+    }
+
+    /// Allows `NavigationTarget` to be created from a `DocCommentsOwner` and a `NameOwner`
+    pub(crate) fn from_doc_commented(
+        db: &RootDatabase,
+        named: InFile<&dyn ast::NameOwner>,
+        node: InFile<&dyn ast::DocCommentsOwner>,
+    ) -> NavigationTarget {
+        let name =
+            named.value.name().map(|it| it.text().clone()).unwrap_or_else(|| SmolStr::new("_"));
+        let frange = original_range(db, node.map(|it| it.syntax()));
+
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            None,
+            frange.range,
+            node.value.syntax().kind(),
         )
     }
 
@@ -159,8 +168,6 @@ impl NavigationTarget {
         focus_range: Option<TextRange>,
         full_range: TextRange,
         kind: SyntaxKind,
-        docs: Option<String>,
-        description: Option<String>,
     ) -> NavigationTarget {
         NavigationTarget {
             file_id,
@@ -169,8 +176,8 @@ impl NavigationTarget {
             full_range,
             focus_range,
             container_name: None,
-            description,
-            docs,
+            description: None,
+            docs: None,
         }
     }
 }
@@ -238,12 +245,11 @@ where
 {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        NavigationTarget::from_named(
-            db,
-            src.as_ref().map(|it| it as &dyn ast::NameOwner),
-            src.value.doc_comment_text(),
-            src.value.short_label(),
-        )
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res.description = src.value.short_label();
+        res
     }
 }
 
@@ -258,35 +264,31 @@ impl ToNav for hir::Module {
             }
         };
         let frange = original_range(db, src.with_value(syntax));
-        NavigationTarget::from_syntax(
-            frange.file_id,
-            name,
-            focus,
-            frange.range,
-            syntax.kind(),
-            None,
-            None,
-        )
+        NavigationTarget::from_syntax(frange.file_id, name, focus, frange.range, syntax.kind())
     }
 }
 
 impl ToNav for hir::ImplDef {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        let frange = if let Some(item) = self.is_builtin_derive(db) {
+        let derive_attr = self.is_builtin_derive(db);
+        let frange = if let Some(item) = &derive_attr {
             original_range(db, item.syntax())
         } else {
             original_range(db, src.as_ref().map(|it| it.syntax()))
         };
+        let focus_range = if derive_attr.is_some() {
+            None
+        } else {
+            src.value.target_type().map(|ty| original_range(db, src.with_value(ty.syntax())).range)
+        };
 
         NavigationTarget::from_syntax(
             frange.file_id,
             "impl".into(),
-            None,
+            focus_range,
             frange.range,
             src.value.syntax().kind(),
-            None,
-            None,
         )
     }
 }
@@ -296,12 +298,12 @@ impl ToNav for hir::Field {
         let src = self.source(db);
 
         match &src.value {
-            FieldSource::Named(it) => NavigationTarget::from_named(
-                db,
-                src.with_value(it),
-                it.doc_comment_text(),
-                it.short_label(),
-            ),
+            FieldSource::Named(it) => {
+                let mut res = NavigationTarget::from_named(db, src.with_value(it));
+                res.docs = it.doc_comment_text();
+                res.description = it.short_label();
+                res
+            }
             FieldSource::Pos(it) => {
                 let frange = original_range(db, src.with_value(it.syntax()));
                 NavigationTarget::from_syntax(
@@ -310,8 +312,6 @@ impl ToNav for hir::Field {
                     None,
                     frange.range,
                     it.syntax().kind(),
-                    None,
-                    None,
                 )
             }
         }
@@ -322,12 +322,10 @@ impl ToNav for hir::MacroDef {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
         log::debug!("nav target {:#?}", src.value.syntax());
-        NavigationTarget::from_named(
-            db,
-            src.as_ref().map(|it| it as &dyn ast::NameOwner),
-            src.value.doc_comment_text(),
-            None,
-        )
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res
     }
 }
 
diff --git a/crates/ra_ide/src/display/structure.rs b/crates/ra_ide/src/display/structure.rs
index aad5a8e4d..1f6a3febf 100644
--- a/crates/ra_ide/src/display/structure.rs
+++ b/crates/ra_ide/src/display/structure.rs
@@ -127,6 +127,7 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
                 decl_with_detail(it, Some(detail))
             },
             ast::StructDef(it) => decl(it),
+            ast::UnionDef(it) => decl(it),
             ast::EnumDef(it) => decl(it),
             ast::EnumVariant(it) => decl(it),
             ast::TraitDef(it) => decl(it),
@@ -173,12 +174,19 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
 
 #[cfg(test)]
 mod tests {
+    use expect::{expect, Expect};
+
     use super::*;
-    use insta::assert_debug_snapshot;
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let file = SourceFile::parse(ra_fixture).ok().unwrap();
+        let structure = file_structure(&file);
+        expect.assert_debug_eq(&structure)
+    }
 
     #[test]
     fn test_file_structure() {
-        let file = SourceFile::parse(
+        check(
             r#"
 struct Foo {
     x: i32
@@ -223,216 +231,211 @@ fn obsolete() {}
 #[deprecated(note = "for awhile")]
 fn very_obsolete() {}
 "#,
-        )
-        .ok()
-        .unwrap();
-        let structure = file_structure(&file);
-        assert_debug_snapshot!(structure,
-        @r###"
-        [
-            StructureNode {
-                parent: None,
-                label: "Foo",
-                navigation_range: 8..11,
-                node_range: 1..26,
-                kind: STRUCT_DEF,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    0,
-                ),
-                label: "x",
-                navigation_range: 18..19,
-                node_range: 18..24,
-                kind: RECORD_FIELD_DEF,
-                detail: Some(
-                    "i32",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "m",
-                navigation_range: 32..33,
-                node_range: 28..158,
-                kind: MODULE,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    2,
-                ),
-                label: "bar1",
-                navigation_range: 43..47,
-                node_range: 40..52,
-                kind: FN_DEF,
-                detail: Some(
-                    "fn()",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    2,
-                ),
-                label: "bar2",
-                navigation_range: 60..64,
-                node_range: 57..81,
-                kind: FN_DEF,
-                detail: Some(
-                    "fn<T>(t: T) -> T",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    2,
-                ),
-                label: "bar3",
-                navigation_range: 89..93,
-                node_range: 86..156,
-                kind: FN_DEF,
-                detail: Some(
-                    "fn<A, B>(a: A, b: B) -> Vec< u32 >",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "E",
-                navigation_range: 165..166,
-                node_range: 160..180,
-                kind: ENUM_DEF,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    6,
-                ),
-                label: "X",
-                navigation_range: 169..170,
-                node_range: 169..170,
-                kind: ENUM_VARIANT,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: Some(
-                    6,
-                ),
-                label: "Y",
-                navigation_range: 172..173,
-                node_range: 172..178,
-                kind: ENUM_VARIANT,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "T",
-                navigation_range: 186..187,
-                node_range: 181..193,
-                kind: TYPE_ALIAS_DEF,
-                detail: Some(
-                    "()",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "S",
-                navigation_range: 201..202,
-                node_range: 194..213,
-                kind: STATIC_DEF,
-                detail: Some(
-                    "i32",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "C",
-                navigation_range: 220..221,
-                node_range: 214..232,
-                kind: CONST_DEF,
-                detail: Some(
-                    "i32",
-                ),
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "impl E",
-                navigation_range: 239..240,
-                node_range: 234..243,
-                kind: IMPL_DEF,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "impl fmt::Debug for E",
-                navigation_range: 265..266,
-                node_range: 245..269,
-                kind: IMPL_DEF,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "mc",
-                navigation_range: 284..286,
-                node_range: 271..303,
-                kind: MACRO_CALL,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "mcexp",
-                navigation_range: 334..339,
-                node_range: 305..356,
-                kind: MACRO_CALL,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "mcexp",
-                navigation_range: 387..392,
-                node_range: 358..409,
-                kind: MACRO_CALL,
-                detail: None,
-                deprecated: false,
-            },
-            StructureNode {
-                parent: None,
-                label: "obsolete",
-                navigation_range: 428..436,
-                node_range: 411..441,
-                kind: FN_DEF,
-                detail: Some(
-                    "fn()",
-                ),
-                deprecated: true,
-            },
-            StructureNode {
-                parent: None,
-                label: "very_obsolete",
-                navigation_range: 481..494,
-                node_range: 443..499,
-                kind: FN_DEF,
-                detail: Some(
-                    "fn()",
-                ),
-                deprecated: true,
-            },
-        ]
-        "###
-                );
+            expect![[r#"
+                [
+                    StructureNode {
+                        parent: None,
+                        label: "Foo",
+                        navigation_range: 8..11,
+                        node_range: 1..26,
+                        kind: STRUCT_DEF,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            0,
+                        ),
+                        label: "x",
+                        navigation_range: 18..19,
+                        node_range: 18..24,
+                        kind: RECORD_FIELD_DEF,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "m",
+                        navigation_range: 32..33,
+                        node_range: 28..158,
+                        kind: MODULE,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar1",
+                        navigation_range: 43..47,
+                        node_range: 40..52,
+                        kind: FN_DEF,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar2",
+                        navigation_range: 60..64,
+                        node_range: 57..81,
+                        kind: FN_DEF,
+                        detail: Some(
+                            "fn<T>(t: T) -> T",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            2,
+                        ),
+                        label: "bar3",
+                        navigation_range: 89..93,
+                        node_range: 86..156,
+                        kind: FN_DEF,
+                        detail: Some(
+                            "fn<A, B>(a: A, b: B) -> Vec< u32 >",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "E",
+                        navigation_range: 165..166,
+                        node_range: 160..180,
+                        kind: ENUM_DEF,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            6,
+                        ),
+                        label: "X",
+                        navigation_range: 169..170,
+                        node_range: 169..170,
+                        kind: ENUM_VARIANT,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: Some(
+                            6,
+                        ),
+                        label: "Y",
+                        navigation_range: 172..173,
+                        node_range: 172..178,
+                        kind: ENUM_VARIANT,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "T",
+                        navigation_range: 186..187,
+                        node_range: 181..193,
+                        kind: TYPE_ALIAS_DEF,
+                        detail: Some(
+                            "()",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "S",
+                        navigation_range: 201..202,
+                        node_range: 194..213,
+                        kind: STATIC_DEF,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "C",
+                        navigation_range: 220..221,
+                        node_range: 214..232,
+                        kind: CONST_DEF,
+                        detail: Some(
+                            "i32",
+                        ),
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "impl E",
+                        navigation_range: 239..240,
+                        node_range: 234..243,
+                        kind: IMPL_DEF,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "impl fmt::Debug for E",
+                        navigation_range: 265..266,
+                        node_range: 245..269,
+                        kind: IMPL_DEF,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mc",
+                        navigation_range: 284..286,
+                        node_range: 271..303,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mcexp",
+                        navigation_range: 334..339,
+                        node_range: 305..356,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "mcexp",
+                        navigation_range: 387..392,
+                        node_range: 358..409,
+                        kind: MACRO_CALL,
+                        detail: None,
+                        deprecated: false,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "obsolete",
+                        navigation_range: 428..436,
+                        node_range: 411..441,
+                        kind: FN_DEF,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: true,
+                    },
+                    StructureNode {
+                        parent: None,
+                        label: "very_obsolete",
+                        navigation_range: 481..494,
+                        node_range: 443..499,
+                        kind: FN_DEF,
+                        detail: Some(
+                            "fn()",
+                        ),
+                        deprecated: true,
+                    },
+                ]
+            "#]],
+        );
     }
 }
diff --git a/crates/ra_ide/src/expand_macro.rs b/crates/ra_ide/src/expand_macro.rs
index 54a47aac0..043515f54 100644
--- a/crates/ra_ide/src/expand_macro.rs
+++ b/crates/ra_ide/src/expand_macro.rs
@@ -2,7 +2,9 @@ use hir::Semantics;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
     algo::{find_node_at_offset, SyntaxRewriter},
-    ast, AstNode, NodeOrToken, SyntaxKind, SyntaxNode, WalkEvent, T,
+    ast, AstNode, NodeOrToken, SyntaxKind,
+    SyntaxKind::*,
+    SyntaxNode, WalkEvent, T,
 };
 
 use crate::FilePosition;
@@ -65,8 +67,6 @@ fn expand_macro_recur(
 // FIXME: It would also be cool to share logic here and in the mbe tests,
 // which are pretty unreadable at the moment.
 fn insert_whitespaces(syn: SyntaxNode) -> String {
-    use SyntaxKind::*;
-
     let mut res = String::new();
     let mut token_iter = syn
         .preorder_with_tokens()
@@ -120,175 +120,164 @@ fn insert_whitespaces(syn: SyntaxNode) -> String {
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_snapshot;
+    use expect::{expect, Expect};
 
     use crate::mock_analysis::analysis_and_position;
 
-    use super::*;
-
-    fn check_expand_macro(fixture: &str) -> ExpandedMacro {
-        let (analysis, pos) = analysis_and_position(fixture);
-        analysis.expand_macro(pos).unwrap().unwrap()
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, pos) = analysis_and_position(ra_fixture);
+        let expansion = analysis.expand_macro(pos).unwrap().unwrap();
+        let actual = format!("{}\n{}", expansion.name, expansion.expansion);
+        expect.assert_eq(&actual);
     }
 
     #[test]
     fn macro_expand_recursive_expansion() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        macro_rules! bar {
-            () => { fn  b() {} }
-        }
-        macro_rules! foo {
-            () => { bar!(); }
-        }
-        macro_rules! baz {
-            () => { foo!(); }
-        }
-        f<|>oo!();
-        "#,
+macro_rules! bar {
+    () => { fn  b() {} }
+}
+macro_rules! foo {
+    () => { bar!(); }
+}
+macro_rules! baz {
+    () => { foo!(); }
+}
+f<|>oo!();
+"#,
+            expect![[r#"
+                foo
+                fn b(){}
+            "#]],
         );
-
-        assert_eq!(res.name, "foo");
-        assert_snapshot!(res.expansion, @r###"
-fn b(){}
-"###);
     }
 
     #[test]
     fn macro_expand_multiple_lines() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        macro_rules! foo {
-            () => {
-                fn some_thing() -> u32 {
-                    let a = 0;
-                    a + 10
-                }
-            }
+macro_rules! foo {
+    () => {
+        fn some_thing() -> u32 {
+            let a = 0;
+            a + 10
         }
-        f<|>oo!();
+    }
+}
+f<|>oo!();
         "#,
+            expect![[r#"
+            foo
+            fn some_thing() -> u32 {
+              let a = 0;
+              a+10
+            }"#]],
         );
-
-        assert_eq!(res.name, "foo");
-        assert_snapshot!(res.expansion, @r###"
-fn some_thing() -> u32 {
-  let a = 0;
-  a+10
-}
-"###);
     }
 
     #[test]
     fn macro_expand_match_ast() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        macro_rules! match_ast {
-            (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+macro_rules! match_ast {
+    (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+    (match ($node:expr) {
+        $( ast::$ast:ident($it:ident) => $res:block, )*
+        _ => $catch_all:expr $(,)?
+    }) => {{
+        $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
+        { $catch_all }
+    }};
+}
 
-            (match ($node:expr) {
-                $( ast::$ast:ident($it:ident) => $res:block, )*
-                _ => $catch_all:expr $(,)?
-            }) => {{
-                $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
-                { $catch_all }
-            }};
+fn main() {
+    mat<|>ch_ast! {
+        match container {
+            ast::TraitDef(it) => {},
+            ast::ImplDef(it) => {},
+            _ => { continue },
         }
-
-        fn main() {
-            mat<|>ch_ast! {
-                match container {
-                    ast::TraitDef(it) => {},
-                    ast::ImplDef(it) => {},
-                    _ => { continue },
-                }
-            }
-        }
-        "#,
-        );
-
-        assert_eq!(res.name, "match_ast");
-        assert_snapshot!(res.expansion, @r###"
-{
-  if let Some(it) = ast::TraitDef::cast(container.clone()){}
-  else if let Some(it) = ast::ImplDef::cast(container.clone()){}
-  else {
-    {
-      continue
     }
-  }
 }
-"###);
+"#,
+            expect![[r#"
+       match_ast
+       {
+         if let Some(it) = ast::TraitDef::cast(container.clone()){}
+         else if let Some(it) = ast::ImplDef::cast(container.clone()){}
+         else {
+           {
+             continue
+           }
+         }
+       }"#]],
+        );
     }
 
     #[test]
     fn macro_expand_match_ast_inside_let_statement() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        macro_rules! match_ast {
-            (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
-            (match ($node:expr) {}) => {{}};
-        }
+macro_rules! match_ast {
+    (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+    (match ($node:expr) {}) => {{}};
+}
 
-        fn main() {
-            let p = f(|it| {
-                let res = mat<|>ch_ast! { match c {}};
-                Some(res)
-            })?;
-        }
-        "#,
+fn main() {
+    let p = f(|it| {
+        let res = mat<|>ch_ast! { match c {}};
+        Some(res)
+    })?;
+}
+"#,
+            expect![[r#"
+                match_ast
+                {}
+            "#]],
         );
-
-        assert_eq!(res.name, "match_ast");
-        assert_snapshot!(res.expansion, @r###"{}"###);
     }
 
     #[test]
     fn macro_expand_inner_macro_fail_to_expand() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        macro_rules! bar {
-            (BAD) => {};
-        }
-        macro_rules! foo {
-            () => {bar!()};
-        }
+macro_rules! bar {
+    (BAD) => {};
+}
+macro_rules! foo {
+    () => {bar!()};
+}
 
-        fn main() {
-            let res = fo<|>o!();
-        }
-        "#,
+fn main() {
+    let res = fo<|>o!();
+}
+"#,
+            expect![[r#"
+                foo
+            "#]],
         );
-
-        assert_eq!(res.name, "foo");
-        assert_snapshot!(res.expansion, @r###""###);
     }
 
     #[test]
     fn macro_expand_with_dollar_crate() {
-        let res = check_expand_macro(
+        check(
             r#"
-        //- /lib.rs
-        #[macro_export]
-        macro_rules! bar {
-            () => {0};
-        }
-        macro_rules! foo {
-            () => {$crate::bar!()};
-        }
+#[macro_export]
+macro_rules! bar {
+    () => {0};
+}
+macro_rules! foo {
+    () => {$crate::bar!()};
+}
 
-        fn main() {
-            let res = fo<|>o!();
-        }
-        "#,
+fn main() {
+    let res = fo<|>o!();
+}
+"#,
+            expect![[r#"
+                foo
+                0 "#]],
         );
-
-        assert_eq!(res.name, "foo");
-        assert_snapshot!(res.expansion, @r###"0"###);
     }
 }
diff --git a/crates/ra_ide/src/extend_selection.rs b/crates/ra_ide/src/extend_selection.rs
index a4bc93cdb..8a6b3ea99 100644
--- a/crates/ra_ide/src/extend_selection.rs
+++ b/crates/ra_ide/src/extend_selection.rs
@@ -315,17 +315,15 @@ fn adj_comments(comment: &ast::Comment, dir: Direction) -> ast::Comment {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::extract_offset;
-
-    use crate::mock_analysis::single_file;
+    use crate::mock_analysis::analysis_and_position;
 
     use super::*;
 
     fn do_check(before: &str, afters: &[&str]) {
-        let (cursor, before) = extract_offset(before);
-        let (analysis, file_id) = single_file(&before);
-        let range = TextRange::empty(cursor);
-        let mut frange = FileRange { file_id, range };
+        let (analysis, position) = analysis_and_position(&before);
+        let before = analysis.file_text(position.file_id).unwrap();
+        let range = TextRange::empty(position.offset);
+        let mut frange = FileRange { file_id: position.file_id, range };
 
         for &after in afters {
             frange.range = analysis.extend_selection(frange).unwrap();
diff --git a/crates/ra_ide/src/folding_ranges.rs b/crates/ra_ide/src/folding_ranges.rs
index 8657377de..e7ec9953f 100644
--- a/crates/ra_ide/src/folding_ranges.rs
+++ b/crates/ra_ide/src/folding_ranges.rs
@@ -15,6 +15,7 @@ pub enum FoldKind {
     Imports,
     Mods,
     Block,
+    ArgList,
 }
 
 #[derive(Debug)]
@@ -83,8 +84,10 @@ fn fold_kind(kind: SyntaxKind) -> Option<FoldKind> {
     match kind {
         COMMENT => Some(FoldKind::Comment),
         USE_ITEM => Some(FoldKind::Imports),
+        ARG_LIST => Some(FoldKind::ArgList),
         RECORD_FIELD_DEF_LIST
         | RECORD_FIELD_PAT_LIST
+        | RECORD_FIELD_LIST
         | ITEM_LIST
         | EXTERN_ITEM_LIST
         | USE_TREE_LIST
@@ -196,89 +199,85 @@ fn contiguous_range_for_comment(
 
 #[cfg(test)]
 mod tests {
+    use test_utils::extract_tags;
+
     use super::*;
-    use test_utils::extract_ranges;
 
-    fn do_check(text: &str, fold_kinds: &[FoldKind]) {
-        let (ranges, text) = extract_ranges(text, "fold");
+    fn check(ra_fixture: &str) {
+        let (ranges, text) = extract_tags(ra_fixture, "fold");
+
         let parse = SourceFile::parse(&text);
         let folds = folding_ranges(&parse.tree());
-
         assert_eq!(
             folds.len(),
             ranges.len(),
             "The amount of folds is different than the expected amount"
         );
-        assert_eq!(
-            folds.len(),
-            fold_kinds.len(),
-            "The amount of fold kinds is different than the expected amount"
-        );
-        for ((fold, range), fold_kind) in
-            folds.iter().zip(ranges.into_iter()).zip(fold_kinds.iter())
-        {
+
+        for (fold, (range, attr)) in folds.iter().zip(ranges.into_iter()) {
             assert_eq!(fold.range.start(), range.start());
             assert_eq!(fold.range.end(), range.end());
-            assert_eq!(&fold.kind, fold_kind);
+
+            let kind = match fold.kind {
+                FoldKind::Comment => "comment",
+                FoldKind::Imports => "imports",
+                FoldKind::Mods => "mods",
+                FoldKind::Block => "block",
+                FoldKind::ArgList => "arglist",
+            };
+            assert_eq!(kind, &attr.unwrap());
         }
     }
 
     #[test]
     fn test_fold_comments() {
-        let text = r#"
-<fold>// Hello
+        check(
+            r#"
+<fold comment>// Hello
 // this is a multiline
 // comment
 //</fold>
 
 // But this is not
 
-fn main() <fold>{
-    <fold>// We should
+fn main() <fold block>{
+    <fold comment>// We should
     // also
     // fold
     // this one.</fold>
-    <fold>//! But this one is different
+    <fold comment>//! But this one is different
     //! because it has another flavor</fold>
-    <fold>/* As does this
+    <fold comment>/* As does this
     multiline comment */</fold>
-}</fold>"#;
-
-        let fold_kinds = &[
-            FoldKind::Comment,
-            FoldKind::Block,
-            FoldKind::Comment,
-            FoldKind::Comment,
-            FoldKind::Comment,
-        ];
-        do_check(text, fold_kinds);
+}</fold>"#,
+        );
     }
 
     #[test]
     fn test_fold_imports() {
-        let text = r#"
-<fold>use std::<fold>{
+        check(
+            r#"
+<fold imports>use std::<fold block>{
     str,
     vec,
     io as iop
 }</fold>;</fold>
 
-fn main() <fold>{
-}</fold>"#;
-
-        let folds = &[FoldKind::Imports, FoldKind::Block, FoldKind::Block];
-        do_check(text, folds);
+fn main() <fold block>{
+}</fold>"#,
+        );
     }
 
     #[test]
     fn test_fold_mods() {
-        let text = r#"
+        check(
+            r#"
 
 pub mod foo;
-<fold>mod after_pub;
+<fold mods>mod after_pub;
 mod after_pub_next;</fold>
 
-<fold>mod before_pub;
+<fold mods>mod before_pub;
 mod before_pub_next;</fold>
 pub mod bar;
 
@@ -286,90 +285,105 @@ mod not_folding_single;
 pub mod foobar;
 pub not_folding_single_next;
 
-<fold>#[cfg(test)]
+<fold mods>#[cfg(test)]
 mod with_attribute;
 mod with_attribute_next;</fold>
 
-fn main() <fold>{
-}</fold>"#;
-
-        let folds = &[FoldKind::Mods, FoldKind::Mods, FoldKind::Mods, FoldKind::Block];
-        do_check(text, folds);
+fn main() <fold block>{
+}</fold>"#,
+        );
     }
 
     #[test]
     fn test_fold_import_groups() {
-        let text = r#"
-<fold>use std::str;
+        check(
+            r#"
+<fold imports>use std::str;
 use std::vec;
 use std::io as iop;</fold>
 
-<fold>use std::mem;
+<fold imports>use std::mem;
 use std::f64;</fold>
 
 use std::collections::HashMap;
 // Some random comment
 use std::collections::VecDeque;
 
-fn main() <fold>{
-}</fold>"#;
-
-        let folds = &[FoldKind::Imports, FoldKind::Imports, FoldKind::Block];
-        do_check(text, folds);
+fn main() <fold block>{
+}</fold>"#,
+        );
     }
 
     #[test]
     fn test_fold_import_and_groups() {
-        let text = r#"
-<fold>use std::str;
+        check(
+            r#"
+<fold imports>use std::str;
 use std::vec;
 use std::io as iop;</fold>
 
-<fold>use std::mem;
+<fold imports>use std::mem;
 use std::f64;</fold>
 
-<fold>use std::collections::<fold>{
+<fold imports>use std::collections::<fold block>{
     HashMap,
     VecDeque,
 }</fold>;</fold>
 // Some random comment
 
-fn main() <fold>{
-}</fold>"#;
-
-        let folds = &[
-            FoldKind::Imports,
-            FoldKind::Imports,
-            FoldKind::Imports,
-            FoldKind::Block,
-            FoldKind::Block,
-        ];
-        do_check(text, folds);
+fn main() <fold block>{
+}</fold>"#,
+        );
     }
 
     #[test]
     fn test_folds_macros() {
-        let text = r#"
-macro_rules! foo <fold>{
+        check(
+            r#"
+macro_rules! foo <fold block>{
     ($($tt:tt)*) => { $($tt)* }
 }</fold>
-"#;
-
-        let folds = &[FoldKind::Block];
-        do_check(text, folds);
+"#,
+        );
     }
 
     #[test]
     fn test_fold_match_arms() {
-        let text = r#"
-fn main() <fold>{
-    match 0 <fold>{
+        check(
+            r#"
+fn main() <fold block>{
+    match 0 <fold block>{
         0 => 0,
         _ => 1,
     }</fold>
-}</fold>"#;
+}</fold>
+"#,
+        );
+    }
+
+    #[test]
+    fn fold_big_calls() {
+        check(
+            r#"
+fn main() <fold block>{
+    frobnicate<fold arglist>(
+        1,
+        2,
+        3,
+    )</fold>
+}</fold>
+"#,
+        )
+    }
 
-        let folds = &[FoldKind::Block, FoldKind::Block];
-        do_check(text, folds);
+    #[test]
+    fn fold_record_literals() {
+        check(
+            r#"
+const _: S = S <fold block>{
+
+}</fold>;
+"#,
+        )
     }
 }
diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index a6c86e99c..c30b20611 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -1,13 +1,13 @@
 use hir::Semantics;
 use ra_ide_db::{
-    defs::{classify_name, classify_name_ref},
+    defs::{classify_name, classify_name_ref, NameClass},
     symbol_index, RootDatabase,
 };
 use ra_syntax::{
     ast::{self},
     match_ast, AstNode,
     SyntaxKind::*,
-    SyntaxToken, TokenAtOffset,
+    SyntaxToken, TokenAtOffset, T,
 };
 
 use crate::{
@@ -32,14 +32,18 @@ pub(crate) fn goto_definition(
     let file = sema.parse(position.file_id).syntax().clone();
     let original_token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(original_token.clone());
+    let parent = token.parent();
 
     let nav_targets = match_ast! {
-        match (token.parent()) {
+        match parent {
             ast::NameRef(name_ref) => {
                 reference_definition(&sema, &name_ref).to_vec()
             },
             ast::Name(name) => {
-                let def = classify_name(&sema, &name)?.definition();
+                let def = match classify_name(&sema, &name)? {
+                    NameClass::Definition(def) | NameClass::ConstReference(def) => def,
+                    NameClass::FieldShorthand { local: _, field } => field,
+                };
                 let nav = def.try_to_nav(sema.db)?;
                 vec![nav]
             },
@@ -54,7 +58,7 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
     return tokens.max_by_key(priority);
     fn priority(n: &SyntaxToken) -> usize {
         match n.kind() {
-            IDENT | INT_NUMBER => 2,
+            IDENT | INT_NUMBER | T![self] => 2,
             kind if kind.is_trivia() => 0,
             _ => 1,
         }
@@ -100,790 +104,784 @@ pub(crate) fn reference_definition(
 
 #[cfg(test)]
 mod tests {
-    use test_utils::assert_eq_text;
-
-    use crate::mock_analysis::analysis_and_position;
-
-    fn check_goto(ra_fixture: &str, expected: &str, expected_range: &str) {
-        let (analysis, pos) = analysis_and_position(ra_fixture);
+    use ra_db::FileRange;
+    use ra_syntax::{TextRange, TextSize};
+
+    use crate::mock_analysis::MockAnalysis;
+
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let (mut expected, data) = mock.annotation();
+        let analysis = mock.analysis();
+        match data.as_str() {
+            "" => (),
+            "file" => {
+                expected.range =
+                    TextRange::up_to(TextSize::of(&*analysis.file_text(expected.file_id).unwrap()))
+            }
+            data => panic!("bad data: {}", data),
+        }
 
-        let mut navs = analysis.goto_definition(pos).unwrap().unwrap().info;
+        let mut navs =
+            analysis.goto_definition(position).unwrap().expect("no definition found").info;
         if navs.len() == 0 {
             panic!("unresolved reference")
         }
         assert_eq!(navs.len(), 1);
 
         let nav = navs.pop().unwrap();
-        let file_text = analysis.file_text(nav.file_id()).unwrap();
-
-        let mut actual = file_text[nav.full_range()].to_string();
-        if let Some(focus) = nav.focus_range() {
-            actual += "|";
-            actual += &file_text[focus];
-        }
-
-        if !expected_range.contains("...") {
-            test_utils::assert_eq_text!(&actual, expected_range);
-        } else {
-            let mut parts = expected_range.split("...");
-            let prefix = parts.next().unwrap();
-            let suffix = parts.next().unwrap();
-            assert!(
-                actual.starts_with(prefix) && actual.ends_with(suffix),
-                "\nExpected: {}\n Actual: {}\n",
-                expected_range,
-                actual
-            );
-        }
-
-        nav.assert_match(expected);
+        assert_eq!(expected, FileRange { file_id: nav.file_id(), range: nav.range() });
     }
 
     #[test]
     fn goto_def_in_items() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            enum E { X(Foo<|>) }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
-            "struct Foo;|Foo",
+        check(
+            r#"
+struct Foo;
+     //^^^
+enum E { X(Foo<|>) }
+"#,
         );
     }
 
     #[test]
     fn goto_def_at_start_of_item() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            enum E { X(<|>Foo) }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
-            "struct Foo;|Foo",
+        check(
+            r#"
+struct Foo;
+     //^^^
+enum E { X(<|>Foo) }
+"#,
         );
     }
 
     #[test]
     fn goto_definition_resolves_correct_name() {
-        check_goto(
-            "
-            //- /lib.rs
-            use a::Foo;
-            mod a;
-            mod b;
-            enum E { X(Foo<|>) }
-
-            //- /a.rs
-            struct Foo;
+        check(
+            r#"
+//- /lib.rs
+use a::Foo;
+mod a;
+mod b;
+enum E { X(Foo<|>) }
 
-            //- /b.rs
-            struct Foo;
-            ",
-            "Foo STRUCT_DEF FileId(2) 0..11 7..10",
-            "struct Foo;|Foo",
+//- /a.rs
+struct Foo;
+     //^^^
+//- /b.rs
+struct Foo;
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_module_declaration() {
-        check_goto(
-            "
-            //- /lib.rs
-            mod <|>foo;
+        check(
+            r#"
+//- /lib.rs
+mod <|>foo;
 
-            //- /foo.rs
-            // empty
-            ",
-            "foo SOURCE_FILE FileId(2) 0..10",
-            "// empty\n\n",
+//- /foo.rs
+// empty
+//^ file
+"#,
         );
 
-        check_goto(
-            "
-            //- /lib.rs
-            mod <|>foo;
+        check(
+            r#"
+//- /lib.rs
+mod <|>foo;
 
-            //- /foo/mod.rs
-            // empty
-            ",
-            "foo SOURCE_FILE FileId(2) 0..10",
-            "// empty\n\n",
+//- /foo/mod.rs
+// empty
+//^ file
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_macros() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! foo { () => { () } }
-
-            fn bar() {
-                <|>foo!();
-            }
-            ",
-            "foo MACRO_CALL FileId(1) 0..33 13..16",
-            "macro_rules! foo { () => { () } }|foo",
+        check(
+            r#"
+macro_rules! foo { () => { () } }
+           //^^^
+fn bar() {
+    <|>foo!();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_macros_from_other_crates() {
-        check_goto(
-            "
-            //- /lib.rs
-            use foo::foo;
-            fn bar() {
-                <|>foo!();
-            }
+        check(
+            r#"
+//- /lib.rs
+use foo::foo;
+fn bar() {
+    <|>foo!();
+}
 
-            //- /foo/lib.rs
-            #[macro_export]
-            macro_rules! foo { () => { () } }
-            ",
-            "foo MACRO_CALL FileId(2) 0..49 29..32",
-            "#[macro_export]\nmacro_rules! foo { () => { () } }|foo",
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
         );
     }
 
     #[test]
-    fn goto_def_for_use_alias() {
-        check_goto(
-            "
-            //- /lib.rs
-            use foo as bar<|>;
-
+    fn goto_def_for_macros_in_use_tree() {
+        check(
+            r#"
+//- /lib.rs
+use foo::foo<|>;
 
-            //- /foo/lib.rs
-            #[macro_export]
-            macro_rules! foo { () => { () } }",
-            "SOURCE_FILE FileId(2) 0..50",
-            "#[macro_export]\nmacro_rules! foo { () => { () } }\n",
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
         );
     }
 
     #[test]
-    fn goto_def_for_use_alias_foo_macro() {
-        check_goto(
-            "
-            //- /lib.rs
-            use foo::foo as bar<|>;
+    fn goto_def_for_macro_defined_fn_with_arg() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! define_fn {
+    ($name:ident) => (fn $name() {})
+}
+
+define_fn!(foo);
+         //^^^
 
-            //- /foo/lib.rs
-            #[macro_export]
-            macro_rules! foo { () => { () } }
-            ",
-            "foo MACRO_CALL FileId(2) 0..49 29..32",
-            "#[macro_export]\nmacro_rules! foo { () => { () } }|foo",
+fn bar() {
+   <|>foo();
+}
+"#,
         );
     }
 
     #[test]
-    fn goto_def_for_macros_in_use_tree() {
-        check_goto(
-            "
-            //- /lib.rs
-            use foo::foo<|>;
+    fn goto_def_for_macro_defined_fn_no_arg() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! define_fn {
+    () => (fn foo() {})
+}
+
+  define_fn!();
+//^^^^^^^^^^^^^
 
-            //- /foo/lib.rs
-            #[macro_export]
-            macro_rules! foo { () => { () } }
-            ",
-            "foo MACRO_CALL FileId(2) 0..49 29..32",
-            "#[macro_export]\nmacro_rules! foo { () => { () } }|foo",
+fn bar() {
+   <|>foo();
+}
+"#,
         );
     }
 
     #[test]
-    fn goto_def_for_macro_defined_fn_with_arg() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! define_fn {
-                ($name:ident) => (fn $name() {})
-            }
-
-            define_fn!(foo);
+    fn goto_definition_works_for_macro_inside_pattern() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! foo {() => {0}}
+           //^^^
 
-            fn bar() {
-               <|>foo();
-            }
-            ",
-            "foo FN_DEF FileId(1) 64..80 75..78",
-            "define_fn!(foo);|foo",
+fn bar() {
+    match (0,1) {
+        (<|>foo!(), _) => {}
+    }
+}
+"#,
         );
     }
 
     #[test]
-    fn goto_def_for_macro_defined_fn_no_arg() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! define_fn {
-                () => (fn foo() {})
-            }
-
-            define_fn!();
-
-            fn bar() {
-               <|>foo();
-            }
-            ",
-            "foo FN_DEF FileId(1) 51..64 51..64",
-            "define_fn!();|define_fn!();",
+    fn goto_definition_works_for_macro_inside_match_arm_lhs() {
+        check(
+            r#"
+//- /lib.rs
+macro_rules! foo {() => {0}}
+           //^^^
+fn bar() {
+    match 0 {
+        <|>foo!() => {}
+    }
+}
+"#,
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macro_inside_pattern() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! foo {() => {0}}
-
-            fn bar() {
-                match (0,1) {
-                    (<|>foo!(), _) => {}
-                }
-            }
-            ",
-            "foo MACRO_CALL FileId(1) 0..28 13..16",
-            "macro_rules! foo {() => {0}}|foo",
+    fn goto_def_for_use_alias() {
+        check(
+            r#"
+//- /lib.rs
+use foo as bar<|>;
+
+//- /foo/lib.rs
+// empty
+//^ file
+"#,
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macro_inside_match_arm_lhs() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! foo {() => {0}}
-
-            fn bar() {
-                match 0 {
-                    <|>foo!() => {}
-                }
-            }
-            ",
-            "foo MACRO_CALL FileId(1) 0..28 13..16",
-            "macro_rules! foo {() => {0}}|foo",
+    fn goto_def_for_use_alias_foo_macro() {
+        check(
+            r#"
+//- /lib.rs
+use foo::foo as bar<|>;
+
+//- /foo/lib.rs
+#[macro_export]
+macro_rules! foo { () => { () } }
+           //^^^
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_methods() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            impl Foo {
-                fn frobnicate(&self) { }
-            }
+        check(
+            r#"
+//- /lib.rs
+struct Foo;
+impl Foo {
+    fn frobnicate(&self) { }
+     //^^^^^^^^^^
+}
 
-            fn bar(foo: &Foo) {
-                foo.frobnicate<|>();
-            }
-            ",
-            "frobnicate FN_DEF FileId(1) 27..51 30..40",
-            "fn frobnicate(&self) { }|frobnicate",
+fn bar(foo: &Foo) {
+    foo.frobnicate<|>();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_fields() {
-        check_goto(
-            r"
-            //- /lib.rs
-            struct Foo {
-                spam: u32,
-            }
+        check(
+            r#"
+struct Foo {
+    spam: u32,
+} //^^^^
 
-            fn bar(foo: &Foo) {
-                foo.spam<|>;
-            }
-            ",
-            "spam RECORD_FIELD_DEF FileId(1) 17..26 17..21",
-            "spam: u32|spam",
+fn bar(foo: &Foo) {
+    foo.spam<|>;
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_record_fields() {
-        check_goto(
-            r"
-            //- /lib.rs
-            struct Foo {
-                spam: u32,
-            }
+        check(
+            r#"
+//- /lib.rs
+struct Foo {
+    spam: u32,
+} //^^^^
 
-            fn bar() -> Foo {
-                Foo {
-                    spam<|>: 0,
-                }
-            }
-            ",
-            "spam RECORD_FIELD_DEF FileId(1) 17..26 17..21",
-            "spam: u32|spam",
+fn bar() -> Foo {
+    Foo {
+        spam<|>: 0,
+    }
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_record_pat_fields() {
-        check_goto(
-            r"
-            //- /lib.rs
-            struct Foo {
-                spam: u32,
-            }
+        check(
+            r#"
+//- /lib.rs
+struct Foo {
+    spam: u32,
+} //^^^^
 
-            fn bar(foo: Foo) -> Foo {
-                let Foo { spam<|>: _, } = foo
-            }
-            ",
-            "spam RECORD_FIELD_DEF FileId(1) 17..26 17..21",
-            "spam: u32|spam",
+fn bar(foo: Foo) -> Foo {
+    let Foo { spam<|>: _, } = foo
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_record_fields_macros() {
-        check_goto(
+        check(
             r"
-            //- /lib.rs
-            macro_rules! m { () => { 92 };}
-            struct Foo { spam: u32 }
+macro_rules! m { () => { 92 };}
+struct Foo { spam: u32 }
+           //^^^^
 
-            fn bar() -> Foo {
-                Foo { spam<|>: m!() }
-            }
-            ",
-            "spam RECORD_FIELD_DEF FileId(1) 45..54 45..49",
-            "spam: u32|spam",
+fn bar() -> Foo {
+    Foo { spam<|>: m!() }
+}
+",
         );
     }
 
     #[test]
     fn goto_for_tuple_fields() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo(u32);
-
-            fn bar() {
-                let foo = Foo(0);
-                foo.<|>0;
-            }
-            ",
-            "TUPLE_FIELD_DEF FileId(1) 11..14",
-            "u32",
+        check(
+            r#"
+struct Foo(u32);
+         //^^^
+
+fn bar() {
+    let foo = Foo(0);
+    foo.<|>0;
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_ufcs_inherent_methods() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            impl Foo {
-                fn frobnicate() { }
-            }
+        check(
+            r#"
+struct Foo;
+impl Foo {
+    fn frobnicate() { }
+}    //^^^^^^^^^^
 
-            fn bar(foo: &Foo) {
-                Foo::frobnicate<|>();
-            }
-            ",
-            "frobnicate FN_DEF FileId(1) 27..46 30..40",
-            "fn frobnicate() { }|frobnicate",
+fn bar(foo: &Foo) {
+    Foo::frobnicate<|>();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_ufcs_trait_methods_through_traits() {
-        check_goto(
-            "
-            //- /lib.rs
-            trait Foo {
-                fn frobnicate();
-            }
+        check(
+            r#"
+trait Foo {
+    fn frobnicate();
+}    //^^^^^^^^^^
 
-            fn bar() {
-                Foo::frobnicate<|>();
-            }
-            ",
-            "frobnicate FN_DEF FileId(1) 16..32 19..29",
-            "fn frobnicate();|frobnicate",
+fn bar() {
+    Foo::frobnicate<|>();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_ufcs_trait_methods_through_self() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            trait Trait {
-                fn frobnicate();
-            }
-            impl Trait for Foo {}
-
-            fn bar() {
-                Foo::frobnicate<|>();
-            }
-            ",
-            "frobnicate FN_DEF FileId(1) 30..46 33..43",
-            "fn frobnicate();|frobnicate",
+        check(
+            r#"
+struct Foo;
+trait Trait {
+    fn frobnicate();
+}    //^^^^^^^^^^
+impl Trait for Foo {}
+
+fn bar() {
+    Foo::frobnicate<|>();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_definition_on_self() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            impl Foo {
-                pub fn new() -> Self {
-                    Self<|> {}
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 12..73",
-            "impl Foo {...}",
-        );
-
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            impl Foo {
-                pub fn new() -> Self<|> {
-                    Self {}
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 12..73",
-            "impl Foo {...}",
-        );
-
-        check_goto(
-            "
-            //- /lib.rs
-            enum Foo { A }
-            impl Foo {
-                pub fn new() -> Self<|> {
-                    Foo::A
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 15..75",
-            "impl Foo {...}",
-        );
-
-        check_goto(
-            "
-            //- /lib.rs
-            enum Foo { A }
-            impl Foo {
-                pub fn thing(a: &Self<|>) {
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 15..62",
-            "impl Foo {...}",
+        check(
+            r#"
+struct Foo;
+impl Foo {
+   //^^^
+    pub fn new() -> Self {
+        Self<|> {}
+    }
+}
+"#,
+        );
+        check(
+            r#"
+struct Foo;
+impl Foo {
+   //^^^
+    pub fn new() -> Self<|> {
+        Self {}
+    }
+}
+"#,
+        );
+
+        check(
+            r#"
+enum Foo { A }
+impl Foo {
+   //^^^
+    pub fn new() -> Self<|> {
+        Foo::A
+    }
+}
+"#,
+        );
+
+        check(
+            r#"
+enum Foo { A }
+impl Foo {
+   //^^^
+    pub fn thing(a: &Self<|>) {
+    }
+}
+"#,
         );
     }
 
     #[test]
     fn goto_definition_on_self_in_trait_impl() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            trait Make {
-                fn new() -> Self;
-            }
-            impl Make for Foo {
-                fn new() -> Self {
-                    Self<|> {}
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 49..115",
-            "impl Make for Foo {...}",
+        check(
+            r#"
+struct Foo;
+trait Make {
+    fn new() -> Self;
+}
+impl Make for Foo {
+            //^^^
+    fn new() -> Self {
+        Self<|> {}
+    }
+}
+"#,
         );
 
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            trait Make {
-                fn new() -> Self;
-            }
-            impl Make for Foo {
-                fn new() -> Self<|> {
-                    Self {}
-                }
-            }
-            ",
-            "impl IMPL_DEF FileId(1) 49..115",
-            "impl Make for Foo {...}",
+        check(
+            r#"
+struct Foo;
+trait Make {
+    fn new() -> Self;
+}
+impl Make for Foo {
+            //^^^
+    fn new() -> Self<|> {
+        Self {}
+    }
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_when_used_on_definition_name_itself() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo<|> { value: u32 }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..25 7..10",
-            "struct Foo { value: u32 }|Foo",
+        check(
+            r#"
+struct Foo<|> { value: u32 }
+     //^^^
+            "#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            struct Foo {
-                field<|>: string,
-            }
-            "#,
-            "field RECORD_FIELD_DEF FileId(1) 17..30 17..22",
-            "field: string|field",
+struct Foo {
+    field<|>: string,
+} //^^^^^
+"#,
         );
 
-        check_goto(
-            "
-            //- /lib.rs
-            fn foo_test<|>() { }
-            ",
-            "foo_test FN_DEF FileId(1) 0..17 3..11",
-            "fn foo_test() { }|foo_test",
+        check(
+            r#"
+fn foo_test<|>() { }
+ //^^^^^^^^
+"#,
         );
 
-        check_goto(
-            "
-            //- /lib.rs
-            enum Foo<|> {
-                Variant,
-            }
-            ",
-            "Foo ENUM_DEF FileId(1) 0..25 5..8",
-            "enum Foo {...}|Foo",
-        );
-
-        check_goto(
-            "
-            //- /lib.rs
-            enum Foo {
-                Variant1,
-                Variant2<|>,
-                Variant3,
-            }
-            ",
-            "Variant2 ENUM_VARIANT FileId(1) 29..37 29..37",
-            "Variant2|Variant2",
+        check(
+            r#"
+enum Foo<|> { Variant }
+   //^^^
+"#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            static INNER<|>: &str = "";
-            "#,
-            "INNER STATIC_DEF FileId(1) 0..24 7..12",
-            "static INNER: &str = \"\";|INNER",
+enum Foo {
+    Variant1,
+    Variant2<|>,
+  //^^^^^^^^
+    Variant3,
+}
+"#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            const INNER<|>: &str = "";
-            "#,
-            "INNER CONST_DEF FileId(1) 0..23 6..11",
-            "const INNER: &str = \"\";|INNER",
+static INNER<|>: &str = "";
+     //^^^^^
+"#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            type Thing<|> = Option<()>;
-            "#,
-            "Thing TYPE_ALIAS_DEF FileId(1) 0..24 5..10",
-            "type Thing = Option<()>;|Thing",
+const INNER<|>: &str = "";
+    //^^^^^
+"#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            trait Foo<|> { }
-            "#,
-            "Foo TRAIT_DEF FileId(1) 0..13 6..9",
-            "trait Foo { }|Foo",
+type Thing<|> = Option<()>;
+   //^^^^^
+"#,
         );
 
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            mod bar<|> { }
-            "#,
-            "bar MODULE FileId(1) 0..11 4..7",
-            "mod bar { }|bar",
+trait Foo<|> { }
+    //^^^
+"#,
+        );
+
+        check(
+            r#"
+mod bar<|> { }
+  //^^^
+"#,
         );
     }
 
     #[test]
     fn goto_from_macro() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            fn foo() {}
-            id! {
-                fn bar() {
-                    fo<|>o();
-                }
-            }
-            mod confuse_index { fn foo(); }
-            ",
-            "foo FN_DEF FileId(1) 52..63 55..58",
-            "fn foo() {}|foo",
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => { $($tt)* }
+}
+fn foo() {}
+ //^^^
+id! {
+    fn bar() {
+        fo<|>o();
+    }
+}
+mod confuse_index { fn foo(); }
+"#,
         );
     }
 
     #[test]
     fn goto_through_format() {
-        check_goto(
-            "
-            //- /lib.rs
-            #[macro_export]
-            macro_rules! format {
-                ($($arg:tt)*) => ($crate::fmt::format($crate::__export::format_args!($($arg)*)))
-            }
-            #[rustc_builtin_macro]
-            #[macro_export]
-            macro_rules! format_args {
-                ($fmt:expr) => ({ /* compiler built-in */ });
-                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
-            }
-            pub mod __export {
-                pub use crate::format_args;
-                fn foo() {} // for index confusion
-            }
-            fn foo() -> i8 {}
-            fn test() {
-                format!(\"{}\", fo<|>o())
-            }
-            ",
-            "foo FN_DEF FileId(1) 398..415 401..404",
-            "fn foo() -> i8 {}|foo",
+        check(
+            r#"
+#[macro_export]
+macro_rules! format {
+    ($($arg:tt)*) => ($crate::fmt::format($crate::__export::format_args!($($arg)*)))
+}
+#[rustc_builtin_macro]
+#[macro_export]
+macro_rules! format_args {
+    ($fmt:expr) => ({ /* compiler built-in */ });
+    ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+}
+pub mod __export {
+    pub use crate::format_args;
+    fn foo() {} // for index confusion
+}
+fn foo() -> i8 {}
+ //^^^
+fn test() {
+    format!("{}", fo<|>o())
+}
+"#,
         );
     }
 
     #[test]
     fn goto_for_type_param() {
-        check_goto(
+        check(
             r#"
-            //- /lib.rs
-            struct Foo<T: Clone> {
-                t: <|>T,
-            }
-            "#,
-            "T TYPE_PARAM FileId(1) 11..19 11..12",
-            "T: Clone|T",
+struct Foo<T: Clone> { t: <|>T }
+         //^
+"#,
         );
     }
 
     #[test]
     fn goto_within_macro() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => ($($tt)*)
-            }
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => ($($tt)*)
+}
 
-            fn foo() {
-                let x = 1;
-                id!({
-                    let y = <|>x;
-                    let z = y;
-                });
-            }
-            ",
-            "x BIND_PAT FileId(1) 69..70",
-            "x",
+fn foo() {
+    let x = 1;
+      //^
+    id!({
+        let y = <|>x;
+        let z = y;
+    });
+}
+"#,
         );
 
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => ($($tt)*)
-            }
+        check(
+            r#"
+macro_rules! id {
+    ($($tt:tt)*) => ($($tt)*)
+}
 
-            fn foo() {
-                let x = 1;
-                id!({
-                    let y = x;
-                    let z = <|>y;
-                });
-            }
-            ",
-            "y BIND_PAT FileId(1) 98..99",
-            "y",
+fn foo() {
+    let x = 1;
+    id!({
+        let y = x;
+          //^
+        let z = <|>y;
+    });
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_in_local_fn() {
-        check_goto(
-            "
-            //- /lib.rs
-            fn main() {
-                fn foo() {
-                    let x = 92;
-                    <|>x;
-                }
-            }
-            ",
-            "x BIND_PAT FileId(1) 39..40",
-            "x",
+        check(
+            r#"
+fn main() {
+    fn foo() {
+        let x = 92;
+          //^
+        <|>x;
+    }
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_in_local_macro() {
-        check_goto(
-            r"
-            //- /lib.rs
-            fn bar() {
-                macro_rules! foo { () => { () } }
-                <|>foo!();
-            }
-            ",
-            "foo MACRO_CALL FileId(1) 15..48 28..31",
-            "macro_rules! foo { () => { () } }|foo",
+        check(
+            r#"
+fn bar() {
+    macro_rules! foo { () => { () } }
+               //^^^
+    <|>foo!();
+}
+"#,
         );
     }
 
     #[test]
     fn goto_def_for_field_init_shorthand() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo { x: i32 }
-            fn main() {
-                let x = 92;
-                Foo { x<|> };
-            }
-            ",
-            "x BIND_PAT FileId(1) 42..43",
-            "x",
+        check(
+            r#"
+struct Foo { x: i32 }
+fn main() {
+    let x = 92;
+      //^
+    Foo { x<|> };
+}
+"#,
         )
     }
+
+    #[test]
+    fn goto_def_for_enum_variant_field() {
+        check(
+            r#"
+enum Foo {
+    Bar { x: i32 }
+}       //^
+fn baz(foo: Foo) {
+    match foo {
+        Foo::Bar { x<|> } => x
+    };
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_pattern_const() {
+        check(
+            r#"
+enum Foo { Bar }
+         //^^^
+impl Foo {
+    fn baz(self) {
+        match self { Self::Bar<|> => {} }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_pattern_record() {
+        check(
+            r#"
+enum Foo { Bar { val: i32 } }
+         //^^^
+impl Foo {
+    fn baz(self) -> i32 {
+        match self { Self::Bar<|> { val } => {} }
+    }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_expr_const() {
+        check(
+            r#"
+enum Foo { Bar }
+         //^^^
+impl Foo {
+    fn baz(self) { Self::Bar<|>; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_enum_variant_self_expr_record() {
+        check(
+            r#"
+enum Foo { Bar { val: i32 } }
+         //^^^
+impl Foo {
+    fn baz(self) { Self::Bar<|> {val: 4}; }
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_for_type_alias_generic_parameter() {
+        check(
+            r#"
+type Alias<T> = T<|>;
+         //^
+"#,
+        )
+    }
+
+    #[test]
+    fn goto_def_for_macro_container() {
+        check(
+            r#"
+//- /lib.rs
+foo::module<|>::mac!();
+
+//- /foo/lib.rs
+pub mod module {
+      //^^^^^^
+    #[macro_export]
+    macro_rules! _mac { () => { () } }
+    pub use crate::_mac as mac;
+}
+"#,
+        );
+    }
 }
diff --git a/crates/ra_ide/src/goto_implementation.rs b/crates/ra_ide/src/goto_implementation.rs
index 0cec0657e..9acc960fc 100644
--- a/crates/ra_ide/src/goto_implementation.rs
+++ b/crates/ra_ide/src/goto_implementation.rs
@@ -74,135 +74,156 @@ fn impls_for_trait(
 
 #[cfg(test)]
 mod tests {
-    use crate::mock_analysis::analysis_and_position;
+    use ra_db::FileRange;
 
-    fn check_goto(fixture: &str, expected: &[&str]) {
-        let (analysis, pos) = analysis_and_position(fixture);
+    use crate::mock_analysis::MockAnalysis;
 
-        let mut navs = analysis.goto_implementation(pos).unwrap().unwrap().info;
-        assert_eq!(navs.len(), expected.len());
-        navs.sort_by_key(|nav| (nav.file_id(), nav.full_range().start()));
-        navs.into_iter().enumerate().for_each(|(i, nav)| nav.assert_match(expected[i]));
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let annotations = mock.annotations();
+        let analysis = mock.analysis();
+
+        let navs = analysis.goto_implementation(position).unwrap().unwrap().info;
+
+        let key = |frange: &FileRange| (frange.file_id, frange.range.start());
+
+        let mut expected = annotations
+            .into_iter()
+            .map(|(range, data)| {
+                assert!(data.is_empty());
+                range
+            })
+            .collect::<Vec<_>>();
+        expected.sort_by_key(key);
+
+        let mut actual = navs
+            .into_iter()
+            .map(|nav| FileRange { file_id: nav.file_id(), range: nav.range() })
+            .collect::<Vec<_>>();
+        actual.sort_by_key(key);
+
+        assert_eq!(expected, actual);
     }
 
     #[test]
     fn goto_implementation_works() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo<|>;
-            impl Foo {}
-            ",
-            &["impl IMPL_DEF FileId(1) 12..23"],
+        check(
+            r#"
+struct Foo<|>;
+impl Foo {}
+   //^^^
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_works_multiple_blocks() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo<|>;
-            impl Foo {}
-            impl Foo {}
-            ",
-            &["impl IMPL_DEF FileId(1) 12..23", "impl IMPL_DEF FileId(1) 24..35"],
+        check(
+            r#"
+struct Foo<|>;
+impl Foo {}
+   //^^^
+impl Foo {}
+   //^^^
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_works_multiple_mods() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo<|>;
-            mod a {
-                impl super::Foo {}
-            }
-            mod b {
-                impl super::Foo {}
-            }
-            ",
-            &["impl IMPL_DEF FileId(1) 24..42", "impl IMPL_DEF FileId(1) 57..75"],
+        check(
+            r#"
+struct Foo<|>;
+mod a {
+    impl super::Foo {}
+       //^^^^^^^^^^
+}
+mod b {
+    impl super::Foo {}
+       //^^^^^^^^^^
+}
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_works_multiple_files() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo<|>;
-            mod a;
-            mod b;
-            //- /a.rs
-            impl crate::Foo {}
-            //- /b.rs
-            impl crate::Foo {}
-            ",
-            &["impl IMPL_DEF FileId(2) 0..18", "impl IMPL_DEF FileId(3) 0..18"],
+        check(
+            r#"
+//- /lib.rs
+struct Foo<|>;
+mod a;
+mod b;
+//- /a.rs
+impl crate::Foo {}
+   //^^^^^^^^^^
+//- /b.rs
+impl crate::Foo {}
+   //^^^^^^^^^^
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_for_trait() {
-        check_goto(
-            "
-            //- /lib.rs
-            trait T<|> {}
-            struct Foo;
-            impl T for Foo {}
-            ",
-            &["impl IMPL_DEF FileId(1) 23..40"],
+        check(
+            r#"
+trait T<|> {}
+struct Foo;
+impl T for Foo {}
+         //^^^
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_for_trait_multiple_files() {
-        check_goto(
-            "
-            //- /lib.rs
-            trait T<|> {};
-            struct Foo;
-            mod a;
-            mod b;
-            //- /a.rs
-            impl crate::T for crate::Foo {}
-            //- /b.rs
-            impl crate::T for crate::Foo {}
-            ",
-            &["impl IMPL_DEF FileId(2) 0..31", "impl IMPL_DEF FileId(3) 0..31"],
+        check(
+            r#"
+//- /lib.rs
+trait T<|> {};
+struct Foo;
+mod a;
+mod b;
+//- /a.rs
+impl crate::T for crate::Foo {}
+                //^^^^^^^^^^
+//- /b.rs
+impl crate::T for crate::Foo {}
+                //^^^^^^^^^^
+            "#,
         );
     }
 
     #[test]
     fn goto_implementation_all_impls() {
-        check_goto(
-            "
-            //- /lib.rs
-            trait T {}
-            struct Foo<|>;
-            impl Foo {}
-            impl T for Foo {}
-            impl T for &Foo {}
-            ",
-            &[
-                "impl IMPL_DEF FileId(1) 23..34",
-                "impl IMPL_DEF FileId(1) 35..52",
-                "impl IMPL_DEF FileId(1) 53..71",
-            ],
+        check(
+            r#"
+//- /lib.rs
+trait T {}
+struct Foo<|>;
+impl Foo {}
+   //^^^
+impl T for Foo {}
+         //^^^
+impl T for &Foo {}
+         //^^^^
+"#,
         );
     }
 
     #[test]
     fn goto_implementation_to_builtin_derive() {
-        check_goto(
-            "
-            //- /lib.rs
-            #[derive(Copy)]
-            struct Foo<|>;
-            ",
-            &["impl IMPL_DEF FileId(1) 0..15"],
+        check(
+            r#"
+  #[derive(Copy)]
+//^^^^^^^^^^^^^^^
+struct Foo<|>;
+
+mod marker {
+    trait Copy {}
+}
+"#,
         );
     }
 }
diff --git a/crates/ra_ide/src/goto_type_definition.rs b/crates/ra_ide/src/goto_type_definition.rs
index 91a3097fb..069cb283e 100644
--- a/crates/ra_ide/src/goto_type_definition.rs
+++ b/crates/ra_ide/src/goto_type_definition.rs
@@ -1,5 +1,5 @@
 use ra_ide_db::RootDatabase;
-use ra_syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset};
+use ra_syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
 
 use crate::{display::ToNav, FilePosition, NavigationTarget, RangeInfo};
 
@@ -25,8 +25,9 @@ pub(crate) fn goto_type_definition(
     let (ty, node) = sema.ancestors_with_macros(token.parent()).find_map(|node| {
         let ty = match_ast! {
             match node {
-                ast::Expr(expr) => sema.type_of_expr(&expr)?,
-                ast::Pat(pat) => sema.type_of_pat(&pat)?,
+                ast::Expr(it) => sema.type_of_expr(&it)?,
+                ast::Pat(it) => sema.type_of_pat(&it)?,
+                ast::SelfParam(it) => sema.type_of_self(&it)?,
                 _ => return None,
             }
         };
@@ -34,7 +35,7 @@ pub(crate) fn goto_type_definition(
         Some((ty, node))
     })?;
 
-    let adt_def = ty.autoderef(db).find_map(|ty| ty.as_adt())?;
+    let adt_def = ty.autoderef(db).filter_map(|ty| ty.as_adt()).last()?;
 
     let nav = adt_def.to_nav(db);
     Some(RangeInfo::new(node.text_range(), vec![nav]))
@@ -44,7 +45,7 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
     return tokens.max_by_key(priority);
     fn priority(n: &SyntaxToken) -> usize {
         match n.kind() {
-            IDENT | INT_NUMBER => 2,
+            IDENT | INT_NUMBER | T![self] => 2,
             kind if kind.is_trivia() => 0,
             _ => 1,
         }
@@ -53,91 +54,98 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
 
 #[cfg(test)]
 mod tests {
-    use crate::mock_analysis::analysis_and_position;
+    use ra_db::FileRange;
 
-    fn check_goto(fixture: &str, expected: &str) {
-        let (analysis, pos) = analysis_and_position(fixture);
+    use crate::mock_analysis::MockAnalysis;
 
-        let mut navs = analysis.goto_type_definition(pos).unwrap().unwrap().info;
+    fn check(ra_fixture: &str) {
+        let (mock, position) = MockAnalysis::with_files_and_position(ra_fixture);
+        let (expected, data) = mock.annotation();
+        assert!(data.is_empty());
+        let analysis = mock.analysis();
+
+        let mut navs = analysis.goto_type_definition(position).unwrap().unwrap().info;
         assert_eq!(navs.len(), 1);
         let nav = navs.pop().unwrap();
-        nav.assert_match(expected);
+        assert_eq!(expected, FileRange { file_id: nav.file_id(), range: nav.range() });
     }
 
     #[test]
     fn goto_type_definition_works_simple() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            fn foo() {
-                let f: Foo;
-                f<|>
-            }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo() {
+    let f: Foo; f<|>
+}
+"#,
         );
     }
 
     #[test]
     fn goto_type_definition_works_simple_ref() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            fn foo() {
-                let f: &Foo;
-                f<|>
-            }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo() {
+    let f: &Foo; f<|>
+}
+"#,
         );
     }
 
     #[test]
     fn goto_type_definition_works_through_macro() {
-        check_goto(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            struct Foo {}
-            id! {
-                fn bar() {
-                    let f<|> = Foo {};
-                }
-            }
-            ",
-            "Foo STRUCT_DEF FileId(1) 52..65 59..62",
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+struct Foo {}
+     //^^^
+id! {
+    fn bar() { let f<|> = Foo {}; }
+}
+"#,
         );
     }
 
     #[test]
     fn goto_type_definition_for_param() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            fn foo(<|>f: Foo) {}
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
+        check(
+            r#"
+struct Foo;
+     //^^^
+fn foo(<|>f: Foo) {}
+"#,
         );
     }
 
     #[test]
     fn goto_type_definition_for_tuple_field() {
-        check_goto(
-            "
-            //- /lib.rs
-            struct Foo;
-            struct Bar(Foo);
-            fn foo() {
-                let bar = Bar(Foo);
-                bar.<|>0;
-            }
-            ",
-            "Foo STRUCT_DEF FileId(1) 0..11 7..10",
+        check(
+            r#"
+struct Foo;
+     //^^^
+struct Bar(Foo);
+fn foo() {
+    let bar = Bar(Foo);
+    bar.<|>0;
+}
+"#,
         );
     }
+
+    #[test]
+    fn goto_def_for_self_param() {
+        check(
+            r#"
+struct Foo;
+     //^^^
+impl Foo {
+    fn f(&self<|>) {}
+}
+"#,
+        )
+    }
 }
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index d96cb5596..a4c97e7f9 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -1,8 +1,6 @@
-use std::iter::once;
-
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, FieldSource, HasSource, HirDisplay, ModuleDef,
-    ModuleSource, Semantics,
+    Adt, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource, HirDisplay,
+    Module, ModuleDef, ModuleSource, Semantics,
 };
 use itertools::Itertools;
 use ra_db::SourceDatabase;
@@ -10,54 +8,66 @@ use ra_ide_db::{
     defs::{classify_name, classify_name_ref, Definition},
     RootDatabase,
 };
-use ra_syntax::{
-    ast::{self, DocCommentsOwner},
-    match_ast, AstNode,
-    SyntaxKind::*,
-    SyntaxToken, TokenAtOffset,
-};
+use ra_syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
+use stdx::format_to;
+use test_utils::mark;
 
 use crate::{
-    display::{macro_label, rust_code_markup, rust_code_markup_with_doc, ShortLabel},
-    FilePosition, RangeInfo,
+    display::{macro_label, ShortLabel, ToNav, TryToNav},
+    markup::Markup,
+    runnables::runnable,
+    FileId, FilePosition, NavigationTarget, RangeInfo, Runnable,
 };
 
-/// Contains the results when hovering over an item
-#[derive(Debug, Default)]
-pub struct HoverResult {
-    results: Vec<String>,
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct HoverConfig {
+    pub implementations: bool,
+    pub run: bool,
+    pub debug: bool,
+    pub goto_type_def: bool,
 }
 
-impl HoverResult {
-    pub fn new() -> HoverResult {
-        Self::default()
+impl Default for HoverConfig {
+    fn default() -> Self {
+        Self { implementations: true, run: true, debug: true, goto_type_def: true }
     }
+}
 
-    pub fn extend(&mut self, item: Option<String>) {
-        self.results.extend(item);
-    }
+impl HoverConfig {
+    pub const NO_ACTIONS: Self =
+        Self { implementations: false, run: false, debug: false, goto_type_def: false };
 
-    pub fn is_empty(&self) -> bool {
-        self.results.is_empty()
+    pub fn any(&self) -> bool {
+        self.implementations || self.runnable() || self.goto_type_def
     }
 
-    pub fn len(&self) -> usize {
-        self.results.len()
+    pub fn none(&self) -> bool {
+        !self.any()
     }
 
-    pub fn first(&self) -> Option<&str> {
-        self.results.first().map(String::as_str)
+    pub fn runnable(&self) -> bool {
+        self.run || self.debug
     }
+}
 
-    pub fn results(&self) -> &[String] {
-        &self.results
-    }
+#[derive(Debug, Clone)]
+pub enum HoverAction {
+    Runnable(Runnable),
+    Implementaion(FilePosition),
+    GoToType(Vec<HoverGotoTypeData>),
+}
 
-    /// Returns the results converted into markup
-    /// for displaying in a UI
-    pub fn to_markup(&self) -> String {
-        self.results.join("\n\n---\n")
-    }
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct HoverGotoTypeData {
+    pub mod_path: String,
+    pub nav: NavigationTarget,
+}
+
+/// Contains the results when hovering over an item
+#[derive(Debug, Default)]
+pub struct HoverResult {
+    pub markup: Markup,
+    pub actions: Vec<HoverAction>,
 }
 
 // Feature: Hover
@@ -70,23 +80,32 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
     let token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(token);
 
-    let mut res = HoverResult::new();
+    let mut res = HoverResult::default();
 
-    if let Some((node, name_kind)) = match_ast! {
-        match (token.parent()) {
-            ast::NameRef(name_ref) => {
-                classify_name_ref(&sema, &name_ref).map(|d| (name_ref.syntax().clone(), d.definition()))
-            },
-            ast::Name(name) => {
-                classify_name(&sema, &name).map(|d| (name.syntax().clone(), d.definition()))
-            },
+    let node = token.parent();
+    let definition = match_ast! {
+        match node {
+            ast::NameRef(name_ref) => classify_name_ref(&sema, &name_ref).map(|d| d.definition()),
+            ast::Name(name) => classify_name(&sema, &name).map(|d| d.definition()),
             _ => None,
         }
-    } {
-        let range = sema.original_range(&node).range;
-        res.extend(hover_text_from_name_kind(db, name_kind));
+    };
+    if let Some(definition) = definition {
+        if let Some(markup) = hover_for_definition(db, definition) {
+            res.markup = markup;
+            if let Some(action) = show_implementations_action(db, definition) {
+                res.actions.push(action);
+            }
 
-        if !res.is_empty() {
+            if let Some(action) = runnable_action(&sema, definition, position.file_id) {
+                res.actions.push(action);
+            }
+
+            if let Some(action) = goto_type_action(db, definition) {
+                res.actions.push(action);
+            }
+
+            let range = sema.original_range(&node).range;
             return Some(RangeInfo::new(range, res));
         }
     }
@@ -97,35 +116,134 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
 
     let ty = match_ast! {
         match node {
-            ast::MacroCall(_it) => {
-                // If this node is a MACRO_CALL, it means that `descend_into_macros` failed to resolve.
-                // (e.g expanding a builtin macro). So we give up here.
-                return None;
-            },
-            ast::Expr(it) => {
-                sema.type_of_expr(&it)
-            },
-            ast::Pat(it) => {
-                sema.type_of_pat(&it)
-            },
-            _ => None,
+            ast::Expr(it) => sema.type_of_expr(&it)?,
+            ast::Pat(it) => sema.type_of_pat(&it)?,
+            // If this node is a MACRO_CALL, it means that `descend_into_macros` failed to resolve.
+            // (e.g expanding a builtin macro). So we give up here.
+            ast::MacroCall(_it) => return None,
+            _ => return None,
         }
-    }?;
+    };
 
-    res.extend(Some(rust_code_markup(&ty.display(db))));
+    res.markup = Markup::fenced_block(&ty.display(db));
     let range = sema.original_range(&node).range;
     Some(RangeInfo::new(range, res))
 }
 
-fn hover_text(
+fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    fn to_action(nav_target: NavigationTarget) -> HoverAction {
+        HoverAction::Implementaion(FilePosition {
+            file_id: nav_target.file_id(),
+            offset: nav_target.range().start(),
+        })
+    }
+
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Adt(Adt::Struct(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Union(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Enum(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Trait(it) => Some(to_action(it.to_nav(db))),
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+fn runnable_action(
+    sema: &Semantics<RootDatabase>,
+    def: Definition,
+    file_id: FileId,
+) -> Option<HoverAction> {
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Module(it) => match it.definition_source(sema.db).value {
+                ModuleSource::Module(it) => runnable(&sema, it.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it)),
+                _ => None,
+            },
+            ModuleDef::Function(it) => {
+                let src = it.source(sema.db);
+                if src.file_id != file_id.into() {
+                    mark::hit!(hover_macro_generated_struct_fn_doc_comment);
+                    mark::hit!(hover_macro_generated_struct_fn_doc_attr);
+
+                    return None;
+                }
+
+                runnable(&sema, src.value.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it))
+            }
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    match def {
+        Definition::Local(it) => {
+            let mut targets: Vec<ModuleDef> = Vec::new();
+            let mut push_new_def = |item: ModuleDef| {
+                if !targets.contains(&item) {
+                    targets.push(item);
+                }
+            };
+
+            it.ty(db).walk(db, |t| {
+                if let Some(adt) = t.as_adt() {
+                    push_new_def(adt.into());
+                } else if let Some(trait_) = t.as_dyn_trait() {
+                    push_new_def(trait_.into());
+                } else if let Some(traits) = t.as_impl_traits(db) {
+                    traits.into_iter().for_each(|it| push_new_def(it.into()));
+                } else if let Some(trait_) = t.as_associated_type_parent_trait(db) {
+                    push_new_def(trait_.into());
+                }
+            });
+
+            let targets = targets
+                .into_iter()
+                .filter_map(|it| {
+                    Some(HoverGotoTypeData {
+                        mod_path: render_path(
+                            db,
+                            it.module(db)?,
+                            it.name(db).map(|name| name.to_string()),
+                        ),
+                        nav: it.try_to_nav(db)?,
+                    })
+                })
+                .collect();
+
+            Some(HoverAction::GoToType(targets))
+        }
+        _ => None,
+    }
+}
+
+fn hover_markup(
     docs: Option<String>,
     desc: Option<String>,
     mod_path: Option<String>,
-) -> Option<String> {
-    if let Some(desc) = desc {
-        Some(rust_code_markup_with_doc(&desc, docs.as_deref(), mod_path.as_deref()))
-    } else {
-        docs
+) -> Option<Markup> {
+    match desc {
+        Some(desc) => {
+            let mut buf = String::new();
+
+            if let Some(mod_path) = mod_path {
+                if !mod_path.is_empty() {
+                    format_to!(buf, "```rust\n{}\n```\n\n", mod_path);
+                }
+            }
+            format_to!(buf, "```rust\n{}\n```", desc);
+
+            if let Some(doc) = docs {
+                format_to!(buf, "\n___\n\n{}", doc);
+            }
+            Some(buf.into())
+        }
+        None => docs.map(Markup::from),
     }
 }
 
@@ -147,35 +265,35 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
     .map(|name| name.to_string())
 }
 
-fn determine_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
-    let mod_path = def.module(db).map(|module| {
-        once(db.crate_graph()[module.krate().into()].display_name.as_ref().map(ToString::to_string))
-            .chain(
-                module
-                    .path_to_root(db)
-                    .into_iter()
-                    .rev()
-                    .map(|it| it.name(db).map(|name| name.to_string())),
-            )
-            .chain(once(definition_owner_name(db, def)))
-            .flatten()
-            .join("::")
-    });
-    mod_path
-}
-
-fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<String> {
-    let mod_path = determine_mod_path(db, &def);
+fn render_path(db: &RootDatabase, module: Module, item_name: Option<String>) -> String {
+    let crate_name =
+        db.crate_graph()[module.krate().into()].display_name.as_ref().map(ToString::to_string);
+    let module_path = module
+        .path_to_root(db)
+        .into_iter()
+        .rev()
+        .flat_map(|it| it.name(db).map(|name| name.to_string()));
+    crate_name.into_iter().chain(module_path).chain(item_name).join("::")
+}
+
+fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
+    def.module(db).map(|module| render_path(db, module, definition_owner_name(db, def)))
+}
+
+fn hover_for_definition(db: &RootDatabase, def: Definition) -> Option<Markup> {
+    let mod_path = definition_mod_path(db, &def);
     return match def {
         Definition::Macro(it) => {
             let src = it.source(db);
-            hover_text(src.value.doc_comment_text(), Some(macro_label(&src.value)), mod_path)
+            let docs = Documentation::from_ast(&src.value).map(Into::into);
+            hover_markup(docs, Some(macro_label(&src.value)), mod_path)
         }
         Definition::Field(it) => {
             let src = it.source(db);
             match src.value {
                 FieldSource::Named(it) => {
-                    hover_text(it.doc_comment_text(), it.short_label(), mod_path)
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
                 }
                 _ => None,
             }
@@ -183,7 +301,8 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
         Definition::ModuleDef(it) => match it {
             ModuleDef::Module(it) => match it.definition_source(db).value {
                 ModuleSource::Module(it) => {
-                    hover_text(it.doc_comment_text(), it.short_label(), mod_path)
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_markup(docs, it.short_label(), mod_path)
                 }
                 _ => None,
             },
@@ -196,22 +315,23 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
             ModuleDef::Static(it) => from_def_source(db, it, mod_path),
             ModuleDef::Trait(it) => from_def_source(db, it, mod_path),
             ModuleDef::TypeAlias(it) => from_def_source(db, it, mod_path),
-            ModuleDef::BuiltinType(it) => Some(it.to_string()),
+            ModuleDef::BuiltinType(it) => return Some(it.to_string().into()),
         },
-        Definition::Local(it) => Some(rust_code_markup(&it.ty(db).display(db))),
+        Definition::Local(it) => return Some(Markup::fenced_block(&it.ty(db).display(db))),
         Definition::TypeParam(_) | Definition::SelfType(_) => {
             // FIXME: Hover for generic param
             None
         }
     };
 
-    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<String>
+    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
     where
         D: HasSource<Ast = A>,
-        A: ast::DocCommentsOwner + ast::NameOwner + ShortLabel,
+        A: ast::DocCommentsOwner + ast::NameOwner + ShortLabel + ast::AttrsOwner,
     {
         let src = def.source(db);
-        hover_text(src.value.doc_comment_text(), src.value.short_label(), mod_path)
+        let docs = Documentation::from_ast(&src.value).map(Into::into);
+        hover_markup(docs, src.value.short_label(), mod_path)
     }
 }
 
@@ -220,7 +340,7 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
     fn priority(n: &SyntaxToken) -> usize {
         match n.kind() {
             IDENT | INT_NUMBER => 3,
-            L_PAREN | R_PAREN => 2,
+            T!['('] | T![')'] => 2,
             kind if kind.is_trivia() => 0,
             _ => 1,
         }
@@ -229,649 +349,682 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
 
 #[cfg(test)]
 mod tests {
+    use expect::{expect, Expect};
     use ra_db::FileLoader;
-    use ra_syntax::TextRange;
 
-    use crate::mock_analysis::{analysis_and_position, single_file_with_position};
+    use crate::mock_analysis::analysis_and_position;
 
-    fn trim_markup(s: &str) -> &str {
-        s.trim_start_matches("```rust\n").trim_end_matches("\n```")
-    }
+    use super::*;
 
-    fn trim_markup_opt(s: Option<&str>) -> Option<&str> {
-        s.map(trim_markup)
+    fn check_hover_no_result(ra_fixture: &str) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        assert!(analysis.hover(position).unwrap().is_none());
     }
 
-    fn check_hover_result(fixture: &str, expected: &[&str]) -> String {
-        let (analysis, position) = analysis_and_position(fixture);
+    fn check(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
         let hover = analysis.hover(position).unwrap().unwrap();
-        let mut results = Vec::from(hover.info.results());
-        results.sort();
-
-        for (markup, expected) in
-            results.iter().zip(expected.iter().chain(std::iter::repeat(&"<missing>")))
-        {
-            assert_eq!(trim_markup(&markup), *expected);
-        }
-
-        assert_eq!(hover.info.len(), expected.len());
 
         let content = analysis.db.file_text(position.file_id);
-        content[hover.range].to_string()
+        let hovered_element = &content[hover.range];
+
+        let actual = format!("*{}*\n{}\n", hovered_element, hover.info.markup);
+        expect.assert_eq(&actual)
     }
 
-    fn check_hover_no_result(fixture: &str) {
-        let (analysis, position) = analysis_and_position(fixture);
-        assert!(analysis.hover(position).unwrap().is_none());
+    fn check_actions(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let hover = analysis.hover(position).unwrap().unwrap();
+        expect.assert_debug_eq(&hover.info.actions)
     }
 
     #[test]
     fn hover_shows_type_of_an_expression() {
-        let (analysis, position) = single_file_with_position(
-            "
-            pub fn foo() -> u32 { 1 }
+        check(
+            r#"
+pub fn foo() -> u32 { 1 }
 
-            fn main() {
-                let foo_test = foo()<|>;
-            }
-            ",
+fn main() {
+    let foo_test = foo()<|>;
+}
+"#,
+            expect![[r#"
+                *foo()*
+                ```rust
+                u32
+                ```
+            "#]],
         );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(hover.range, TextRange::new(95.into(), 100.into()));
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("u32"));
     }
 
     #[test]
     fn hover_shows_long_type_of_an_expression() {
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            struct Scan<A, B, C> {
-                a: A,
-                b: B,
-                c: C,
-            }
+struct Scan<A, B, C> { a: A, b: B, c: C }
+struct Iter<I> { inner: I }
+enum Option<T> { Some(T), None }
 
-            struct FakeIter<I> {
-                inner: I,
-            }
-
-            struct OtherStruct<T> {
-                i: T,
-            }
+struct OtherStruct<T> { i: T }
 
-            enum FakeOption<T> {
-                Some(T),
-                None,
-            }
-
-            fn scan<A, B, C>(a: A, b: B, c: C) -> FakeIter<Scan<OtherStruct<A>, B, C>> {
-                FakeIter { inner: Scan { a, b, c } }
-            }
+fn scan<A, B, C>(a: A, b: B, c: C) -> Iter<Scan<OtherStruct<A>, B, C>> {
+    Iter { inner: Scan { a, b, c } }
+}
 
-            fn main() {
-                let num: i32 = 55;
-                let closure = |memo: &mut u32, value: &u32, _another: &mut u32| -> FakeOption<u32> {
-                    FakeOption::Some(*memo + value)
-                };
-                let number = 5u32;
-                let mut iter<|> = scan(OtherStruct { i: num }, closure, number);
-            }
-            "#,
-            &["FakeIter<Scan<OtherStruct<OtherStruct<i32>>, |&mut u32, &u32, &mut u32| -> FakeOption<u32>, u32>>"],
+fn main() {
+    let num: i32 = 55;
+    let closure = |memo: &mut u32, value: &u32, _another: &mut u32| -> Option<u32> {
+        Option::Some(*memo + value)
+    };
+    let number = 5u32;
+    let mut iter<|> = scan(OtherStruct { i: num }, closure, number);
+}
+"#,
+            expect![[r#"
+                *iter*
+                ```rust
+                Iter<Scan<OtherStruct<OtherStruct<i32>>, |&mut u32, &u32, &mut u32| -> Option<u32>, u32>>
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_shows_fn_signature() {
         // Single file with result
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            pub fn foo() -> u32 { 1 }
-
-            fn main() {
-                let foo_test = fo<|>o();
-            }
-        "#,
-            &["pub fn foo() -> u32"],
+pub fn foo() -> u32 { 1 }
+
+fn main() { let foo_test = fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo() -> u32
+                ```
+            "#]],
         );
 
         // Multiple candidates but results are ambiguous.
-        check_hover_result(
+        check(
             r#"
-            //- /a.rs
-            pub fn foo() -> u32 { 1 }
+//- /a.rs
+pub fn foo() -> u32 { 1 }
 
-            //- /b.rs
-            pub fn foo() -> &str { "" }
+//- /b.rs
+pub fn foo() -> &str { "" }
 
-            //- /c.rs
-            pub fn foo(a: u32, b: u32) {}
+//- /c.rs
+pub fn foo(a: u32, b: u32) {}
 
-            //- /main.rs
-            mod a;
-            mod b;
-            mod c;
+//- /main.rs
+mod a;
+mod b;
+mod c;
 
-            fn main() {
-                let foo_test = fo<|>o();
-            }
+fn main() { let foo_test = fo<|>o(); }
         "#,
-            &["{unknown}"],
+            expect![[r#"
+                *foo*
+                ```rust
+                {unknown}
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_shows_fn_signature_with_type_params() {
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str { }
+pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str { }
 
-            fn main() {
-                let foo_test = fo<|>o();
-            }
+fn main() { let foo_test = fo<|>o(); }
         "#,
-            &["pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str"],
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_shows_fn_signature_on_fn_name() {
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            pub fn foo<|>(a: u32, b: u32) -> u32 {}
-
-            fn main() {
-            }
-        "#,
-            &["pub fn foo(a: u32, b: u32) -> u32"],
+pub fn foo<|>(a: u32, b: u32) -> u32 {}
+
+fn main() { }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub fn foo(a: u32, b: u32) -> u32
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_shows_struct_field_info() {
         // Hovering over the field when instantiating
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            struct Foo {
-                field_a: u32,
-            }
+struct Foo { field_a: u32 }
 
-            fn main() {
-                let foo = Foo {
-                    field_a<|>: 0,
-                };
-            }
-        "#,
-            &["Foo\n```\n\n```rust\nfield_a: u32"],
+fn main() {
+    let foo = Foo { field_a<|>: 0, };
+}
+"#,
+            expect![[r#"
+                *field_a*
+                ```rust
+                Foo
+                ```
+
+                ```rust
+                field_a: u32
+                ```
+            "#]],
         );
 
         // Hovering over the field in the definition
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            struct Foo {
-                field_a<|>: u32,
-            }
+struct Foo { field_a<|>: u32 }
 
-            fn main() {
-                let foo = Foo {
-                    field_a: 0,
-                };
-            }
-        "#,
-            &["Foo\n```\n\n```rust\nfield_a: u32"],
+fn main() {
+    let foo = Foo { field_a: 0 };
+}
+"#,
+            expect![[r#"
+                *field_a*
+                ```rust
+                Foo
+                ```
+
+                ```rust
+                field_a: u32
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_const_static() {
-        check_hover_result(
-            r#"
-            //- /main.rs
-            const foo<|>: u32 = 0;
-        "#,
-            &["const foo: u32"],
+        check(
+            r#"const foo<|>: u32 = 0;"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                const foo: u32
+                ```
+            "#]],
         );
-
-        check_hover_result(
-            r#"
-            //- /main.rs
-            static foo<|>: u32 = 0;
-        "#,
-            &["static foo: u32"],
+        check(
+            r#"static foo<|>: u32 = 0;"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                static foo: u32
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_default_generic_types() {
-        check_hover_result(
+        check(
             r#"
-//- /main.rs
-struct Test<K, T = u8> {
-    k: K,
-    t: T,
-}
+struct Test<K, T = u8> { k: K, t: T }
 
 fn main() {
-    let zz<|> = Test { t: 23, k: 33 };
+    let zz<|> = Test { t: 23u8, k: 33 };
 }"#,
-            &["Test<i32, u8>"],
+            expect![[r#"
+                *zz*
+                ```rust
+                Test<i32, u8>
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn hover_some() {
-        let (analysis, position) = single_file_with_position(
-            "
-            enum Option<T> { Some(T) }
-            use Option::Some;
-
-            fn main() {
-                So<|>me(12);
-            }
-            ",
+        check(
+            r#"
+enum Option<T> { Some(T) }
+use Option::Some;
+
+fn main() { So<|>me(12); }
+"#,
+            expect![[r#"
+                *Some*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                Some
+                ```
+            "#]],
         );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("Option\n```\n\n```rust\nSome"));
-
-        let (analysis, position) = single_file_with_position(
-            "
-            enum Option<T> { Some(T) }
-            use Option::Some;
 
-            fn main() {
-                let b<|>ar = Some(12);
-            }
-            ",
+        check(
+            r#"
+enum Option<T> { Some(T) }
+use Option::Some;
+
+fn main() { let b<|>ar = Some(12); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                Option<i32>
+                ```
+            "#]],
         );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("Option<i32>"));
     }
 
     #[test]
     fn hover_enum_variant() {
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            enum Option<T> {
-                /// The None variant
-                Non<|>e
-            }
-        "#,
-            &["
-Option
-```
-
-```rust
-None
-```
-___
-
-The None variant
-            "
-            .trim()],
+enum Option<T> {
+    /// The None variant
+    Non<|>e
+}
+"#,
+            expect![[r#"
+                *None*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                None
+                ```
+                ___
+
+                The None variant
+            "#]],
         );
 
-        check_hover_result(
+        check(
             r#"
-            //- /main.rs
-            enum Option<T> {
-                /// The Some variant
-                Some(T)
-            }
-            fn main() {
-                let s = Option::Som<|>e(12);
-            }
-        "#,
-            &["
-Option
-```
-
-```rust
-Some
-```
-___
-
-The Some variant
-            "
-            .trim()],
+enum Option<T> {
+    /// The Some variant
+    Some(T)
+}
+fn main() {
+    let s = Option::Som<|>e(12);
+}
+"#,
+            expect![[r#"
+                *Some*
+                ```rust
+                Option
+                ```
+
+                ```rust
+                Some
+                ```
+                ___
+
+                The Some variant
+            "#]],
         );
     }
 
     #[test]
     fn hover_for_local_variable() {
-        let (analysis, position) = single_file_with_position("fn func(foo: i32) { fo<|>o; }");
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+        check(
+            r#"fn func(foo: i32) { fo<|>o; }"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn hover_for_local_variable_pat() {
-        let (analysis, position) = single_file_with_position("fn func(fo<|>o: i32) {}");
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+        check(
+            r#"fn func(fo<|>o: i32) {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn hover_local_var_edge() {
-        let (analysis, position) = single_file_with_position(
-            "
-fn func(foo: i32) { if true { <|>foo; }; }
-",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+        check(
+            r#"fn func(foo: i32) { if true { <|>foo; }; }"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn hover_for_param_edge() {
-        let (analysis, position) = single_file_with_position("fn func(<|>foo: i32) {}");
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+        check(
+            r#"fn func(<|>foo: i32) {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_infer_associated_method_result() {
-        let (analysis, position) = single_file_with_position(
-            "
-            struct Thing { x: u32 }
+        check(
+            r#"
+struct Thing { x: u32 }
 
-            impl Thing {
-                fn new() -> Thing {
-                    Thing { x: 0 }
-                }
-            }
+impl Thing {
+    fn new() -> Thing { Thing { x: 0 } }
+}
 
-            fn main() {
-                let foo_<|>test = Thing::new();
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
+fn main() { let foo_<|>test = Thing::new(); }
+            "#,
+            expect![[r#"
+                *foo_test*
+                ```rust
+                Thing
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_infer_associated_method_exact() {
-        let (analysis, position) = single_file_with_position(
-            "
-            mod wrapper {
-                struct Thing { x: u32 }
+        check(
+            r#"
+mod wrapper {
+    struct Thing { x: u32 }
 
-                impl Thing {
-                    fn new() -> Thing {
-                        Thing { x: 0 }
-                    }
-                }
-            }
+    impl Thing {
+        fn new() -> Thing { Thing { x: 0 } }
+    }
+}
 
-            fn main() {
-                let foo_test = wrapper::Thing::new<|>();
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(
-            trim_markup_opt(hover.info.first()),
-            Some("wrapper::Thing\n```\n\n```rust\nfn new() -> Thing")
-        );
+fn main() { let foo_test = wrapper::Thing::new<|>(); }
+"#,
+            expect![[r#"
+                *new*
+                ```rust
+                wrapper::Thing
+                ```
+
+                ```rust
+                fn new() -> Thing
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_infer_associated_const_in_pattern() {
-        let (analysis, position) = single_file_with_position(
-            "
-            struct X;
-            impl X {
-                const C: u32 = 1;
-            }
+        check(
+            r#"
+struct X;
+impl X {
+    const C: u32 = 1;
+}
 
-            fn main() {
-                match 1 {
-                    X::C<|> => {},
-                    2 => {},
-                    _ => {}
-                };
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("const C: u32"));
+fn main() {
+    match 1 {
+        X::C<|> => {},
+        2 => {},
+        _ => {}
+    };
+}
+"#,
+            expect![[r#"
+                *C*
+                ```rust
+                const C: u32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_self() {
-        let (analysis, position) = single_file_with_position(
-            "
-            struct Thing { x: u32 }
-            impl Thing {
-                fn new() -> Self {
-                    Self<|> { x: 0 }
-                }
-            }
-        ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
-
-        /* FIXME: revive these tests
-                let (analysis, position) = single_file_with_position(
-                    "
-                    struct Thing { x: u32 }
-                    impl Thing {
-                        fn new() -> Self<|> {
-                            Self { x: 0 }
-                        }
-                    }
-                    ",
-                );
-
-                let hover = analysis.hover(position).unwrap().unwrap();
-                assert_eq!(trim_markup_opt(hover.info.first()), Some("Thing"));
-
-                let (analysis, position) = single_file_with_position(
-                    "
-                    enum Thing { A }
-                    impl Thing {
-                        pub fn new() -> Self<|> {
-                            Thing::A
-                        }
-                    }
-                    ",
-                );
-                let hover = analysis.hover(position).unwrap().unwrap();
-                assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
-
-                let (analysis, position) = single_file_with_position(
-                    "
-                    enum Thing { A }
-                    impl Thing {
-                        pub fn thing(a: Self<|>) {
-                        }
-                    }
-                    ",
-                );
-                let hover = analysis.hover(position).unwrap().unwrap();
-                assert_eq!(trim_markup_opt(hover.info.first()), Some("enum Thing"));
-        */
-    }
+        check(
+            r#"
+struct Thing { x: u32 }
+impl Thing {
+    fn new() -> Self { Self<|> { x: 0 } }
+}
+"#,
+            expect![[r#"
+                *Self { x: 0 }*
+                ```rust
+                Thing
+                ```
+            "#]],
+        )
+    } /* FIXME: revive these tests
+              let (analysis, position) = analysis_and_position(
+                  "
+                  struct Thing { x: u32 }
+                  impl Thing {
+                      fn new() -> Self<|> {
+                          Self { x: 0 }
+                      }
+                  }
+                  ",
+              );
+
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("Thing"));
+
+              let (analysis, position) = analysis_and_position(
+                  "
+                  enum Thing { A }
+                  impl Thing {
+                      pub fn new() -> Self<|> {
+                          Thing::A
+                      }
+                  }
+                  ",
+              );
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("enum Thing"));
+
+              let (analysis, position) = analysis_and_position(
+                  "
+                  enum Thing { A }
+                  impl Thing {
+                      pub fn thing(a: Self<|>) {
+                      }
+                  }
+                  ",
+              );
+              let hover = analysis.hover(position).unwrap().unwrap();
+              assert_eq!(trim_markup(&hover.info.markup.as_str()), ("enum Thing"));
+      */
 
     #[test]
     fn test_hover_shadowing_pat() {
-        let (analysis, position) = single_file_with_position(
-            "
-            fn x() {}
+        check(
+            r#"
+fn x() {}
 
-            fn y() {
-                let x = 0i32;
-                x<|>;
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+fn y() {
+    let x = 0i32;
+    x<|>;
+}
+"#,
+            expect![[r#"
+                *x*
+                ```rust
+                i32
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_macro_invocation() {
-        let (analysis, position) = single_file_with_position(
-            "
-            macro_rules! foo {
-                () => {}
-            }
-
-            fn f() {
-                fo<|>o!();
-            }
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("macro_rules! foo"));
+        check(
+            r#"
+macro_rules! foo { () => {} }
+
+fn f() { fo<|>o!(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                macro_rules! foo
+                ```
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_tuple_field() {
-        let (analysis, position) = single_file_with_position(
-            "
-            struct TS(String, i32<|>);
-            ",
-        );
-        let hover = analysis.hover(position).unwrap().unwrap();
-        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+        check(
+            r#"struct TS(String, i32<|>);"#,
+            expect![[r#"
+                *i32*
+                i32
+            "#]],
+        )
     }
 
     #[test]
     fn test_hover_through_macro() {
-        let hover_on = check_hover_result(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            fn foo() {}
-            id! {
-                fn bar() {
-                    fo<|>o();
-                }
-            }
-            ",
-            &["fn foo()"],
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo() {}
+id! {
+    fn bar() { fo<|>o(); }
+}
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                fn foo()
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "foo")
     }
 
     #[test]
     fn test_hover_through_expr_in_macro() {
-        let hover_on = check_hover_result(
-            "
-            //- /lib.rs
-            macro_rules! id {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            fn foo(bar:u32) {
-                let a = id!(ba<|>r);
-            }
-            ",
-            &["u32"],
+        check(
+            r#"
+macro_rules! id { ($($tt:tt)*) => { $($tt)* } }
+fn foo(bar:u32) { let a = id!(ba<|>r); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                u32
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "bar")
     }
 
     #[test]
     fn test_hover_through_expr_in_macro_recursive() {
-        let hover_on = check_hover_result(
-            "
-            //- /lib.rs
-            macro_rules! id_deep {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            macro_rules! id {
-                ($($tt:tt)*) => { id_deep!($($tt)*) }
-            }
-            fn foo(bar:u32) {
-                let a = id!(ba<|>r);
-            }
-            ",
-            &["u32"],
+        check(
+            r#"
+macro_rules! id_deep { ($($tt:tt)*) => { $($tt)* } }
+macro_rules! id { ($($tt:tt)*) => { id_deep!($($tt)*) } }
+fn foo(bar:u32) { let a = id!(ba<|>r); }
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                u32
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "bar")
     }
 
     #[test]
     fn test_hover_through_func_in_macro_recursive() {
-        let hover_on = check_hover_result(
-            "
-            //- /lib.rs
-            macro_rules! id_deep {
-                ($($tt:tt)*) => { $($tt)* }
-            }
-            macro_rules! id {
-                ($($tt:tt)*) => { id_deep!($($tt)*) }
-            }
-            fn bar() -> u32 {
-                0
-            }
-            fn foo() {
-                let a = id!([0u32, bar(<|>)] );
-            }
-            ",
-            &["u32"],
+        check(
+            r#"
+macro_rules! id_deep { ($($tt:tt)*) => { $($tt)* } }
+macro_rules! id { ($($tt:tt)*) => { id_deep!($($tt)*) } }
+fn bar() -> u32 { 0 }
+fn foo() { let a = id!([0u32, bar(<|>)] ); }
+"#,
+            expect![[r#"
+                *bar()*
+                ```rust
+                u32
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "bar()")
     }
 
     #[test]
     fn test_hover_through_literal_string_in_macro() {
-        let hover_on = check_hover_result(
+        check(
             r#"
-            //- /lib.rs
-            macro_rules! arr {
-                ($($tt:tt)*) => { [$($tt)*)] }
-            }
-            fn foo() {
-                let mastered_for_itunes = "";
-                let _ = arr!("Tr<|>acks", &mastered_for_itunes);
-            }
-            "#,
-            &["&str"],
+macro_rules! arr { ($($tt:tt)*) => { [$($tt)*)] } }
+fn foo() {
+    let mastered_for_itunes = "";
+    let _ = arr!("Tr<|>acks", &mastered_for_itunes);
+}
+"#,
+            expect![[r#"
+                *"Tracks"*
+                ```rust
+                &str
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "\"Tracks\"");
     }
 
     #[test]
     fn test_hover_through_assert_macro() {
-        let hover_on = check_hover_result(
+        check(
             r#"
-            //- /lib.rs
-            #[rustc_builtin_macro]
-            macro_rules! assert {}
+#[rustc_builtin_macro]
+macro_rules! assert {}
 
-            fn bar() -> bool { true }
-            fn foo() {
-                assert!(ba<|>r());
-            }
-            "#,
-            &["fn bar() -> bool"],
+fn bar() -> bool { true }
+fn foo() {
+    assert!(ba<|>r());
+}
+"#,
+            expect![[r#"
+                *bar*
+                ```rust
+                fn bar() -> bool
+                ```
+            "#]],
         );
-
-        assert_eq!(hover_on, "bar");
     }
 
     #[test]
     fn test_hover_through_literal_string_in_builtin_macro() {
         check_hover_no_result(
             r#"
-            //- /lib.rs
             #[rustc_builtin_macro]
             macro_rules! format {}
 
@@ -884,71 +1037,1351 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_non_ascii_space_doc() {
-        check_hover_result(
+        check(
             "
-            //- /lib.rs
-            ///　<- `\u{3000}` here
-            fn foo() {
-            }
+///　<- `\u{3000}` here
+fn foo() { }
 
-            fn bar() {
-                fo<|>o();
-            }
-            ",
-            &["fn foo()\n```\n___\n\n<- `\u{3000}` here"],
+fn bar() { fo<|>o(); }
+",
+            expect![[r#"
+                *foo*
+                ```rust
+                fn foo()
+                ```
+                ___
+
+                <- `　` here
+            "#]],
         );
     }
 
     #[test]
     fn test_hover_function_show_qualifiers() {
-        check_hover_result(
-            "
-            //- /lib.rs
-            async fn foo<|>() {}
-            ",
-            &["async fn foo()"],
+        check(
+            r#"async fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                async fn foo()
+                ```
+            "#]],
         );
-        check_hover_result(
-            "
-            //- /lib.rs
-            pub const unsafe fn foo<|>() {}
-            ",
-            &["pub const unsafe fn foo()"],
+        check(
+            r#"pub const unsafe fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub const unsafe fn foo()
+                ```
+            "#]],
         );
-        check_hover_result(
-            r#"
-            //- /lib.rs
-            pub(crate) async unsafe extern "C" fn foo<|>() {}
-            "#,
-            &[r#"pub(crate) async unsafe extern "C" fn foo()"#],
+        check(
+            r#"pub(crate) async unsafe extern "C" fn foo<|>() {}"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                pub(crate) async unsafe extern "C" fn foo()
+                ```
+            "#]],
         );
     }
 
     #[test]
     fn test_hover_trait_show_qualifiers() {
-        check_hover_result(
-            "
-            //- /lib.rs
-            unsafe trait foo<|>() {}
-            ",
-            &["unsafe trait foo"],
+        check_actions(
+            r"unsafe trait foo<|>() {}",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 13,
+                        },
+                    ),
+                ]
+            "#]],
         );
     }
 
     #[test]
     fn test_hover_mod_with_same_name_as_function() {
-        check_hover_result(
-            "
-            //- /lib.rs
-            use self::m<|>y::Bar;
+        check(
+            r#"
+use self::m<|>y::Bar;
+mod my { pub struct Bar; }
+
+fn my() {}
+"#,
+            expect![[r#"
+                *my*
+                ```rust
+                mod my
+                ```
+            "#]],
+        );
+    }
 
-            mod my {
-                pub struct Bar;
-            }
+    #[test]
+    fn test_hover_struct_doc_comment() {
+        check(
+            r#"
+/// bar docs
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr() {
+        check(
+            r#"
+#[doc = "bar docs"]
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr_multiple_and_mixed() {
+        check(
+            r#"
+/// bar docs 0
+#[doc = "bar docs 1"]
+#[doc = "bar docs 2"]
+struct Bar;
+
+fn foo() { let bar = Ba<|>r; }
+"#,
+            expect![[r#"
+                *Bar*
+                ```rust
+                struct Bar
+                ```
+                ___
+
+                bar docs 0
+
+                bar docs 1
+
+                bar docs 2
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_comment() {
+        mark::check!(hover_macro_generated_struct_fn_doc_comment);
+
+        check(
+            r#"
+macro_rules! bar {
+    () => {
+        struct Bar;
+        impl Bar {
+            /// Do the foo
+            fn foo(&self) {}
+        }
+    }
+}
+
+bar!();
+
+fn foo() { let bar = Bar; bar.fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                Bar
+                ```
+
+                ```rust
+                fn foo(&self)
+                ```
+                ___
+
+                 Do the foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_attr() {
+        mark::check!(hover_macro_generated_struct_fn_doc_attr);
+
+        check(
+            r#"
+macro_rules! bar {
+    () => {
+        struct Bar;
+        impl Bar {
+            #[doc = "Do the foo"]
+            fn foo(&self) {}
+        }
+    }
+}
+
+bar!();
+
+fn foo() { let bar = Bar; bar.fo<|>o(); }
+"#,
+            expect![[r#"
+                *foo*
+                ```rust
+                Bar
+                ```
+
+                ```rust
+                fn foo(&self)
+                ```
+                ___
+
+                Do the foo
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_trait_has_impl_action() {
+        check_actions(
+            r#"trait foo<|>() {}"#,
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 6,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_has_impl_action() {
+        check_actions(
+            r"struct foo<|>() {}",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 7,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_union_has_impl_action() {
+        check_actions(
+            r#"union foo<|>() {}"#,
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 6,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_enum_has_impl_action() {
+        check_actions(
+            r"enum foo<|>() { A, B }",
+            expect![[r#"
+                [
+                    Implementaion(
+                        FilePosition {
+                            file_id: FileId(
+                                1,
+                            ),
+                            offset: 5,
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_test_has_action() {
+        check_actions(
+            r#"
+#[test]
+fn foo_<|>test() {}
+"#,
+            expect![[r#"
+                [
+                    Runnable(
+                        Runnable {
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..24,
+                                name: "foo_test",
+                                kind: FN_DEF,
+                                focus_range: Some(
+                                    11..19,
+                                ),
+                                container_name: None,
+                                description: None,
+                                docs: None,
+                            },
+                            kind: Test {
+                                test_id: Path(
+                                    "foo_test",
+                                ),
+                                attr: TestAttr {
+                                    ignore: false,
+                                },
+                            },
+                            cfg_exprs: [],
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_test_mod_has_action() {
+        check_actions(
+            r#"
+mod tests<|> {
+    #[test]
+    fn foo_test() {}
+}
+"#,
+            expect![[r#"
+                [
+                    Runnable(
+                        Runnable {
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..46,
+                                name: "tests",
+                                kind: MODULE,
+                                focus_range: Some(
+                                    4..9,
+                                ),
+                                container_name: None,
+                                description: None,
+                                docs: None,
+                            },
+                            kind: TestMod {
+                                path: "tests",
+                            },
+                            cfg_exprs: [],
+                        },
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_has_goto_type_action() {
+        check_actions(
+            r#"
+struct S{ f1: u32 }
+
+fn main() { let s<|>t = S{ f1:0 }; }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..19,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        7..8,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_goto_type_actions() {
+        check_actions(
+            r#"
+struct Arg(u32);
+struct S<T>{ f1: T }
+
+fn main() { let s<|>t = S{ f1:Arg(0) }; }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 17..37,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        24..25,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Arg",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..16,
+                                    name: "Arg",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        7..10,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct Arg",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_flattened_goto_type_actions() {
+        check_actions(
+            r#"
+struct Arg(u32);
+struct S<T>{ f1: T }
+
+fn main() { let s<|>t = S{ f1: S{ f1: Arg(0) } }; }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 17..37,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        24..25,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Arg",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..16,
+                                    name: "Arg",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        7..10,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct Arg",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_tuple_has_goto_type_actions() {
+        check_actions(
+            r#"
+struct A(u32);
+struct B(u32);
+mod M {
+    pub struct C(u32);
+}
+
+fn main() { let s<|>t = (A(1), B(2), M::C(3) ); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "A",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..14,
+                                    name: "A",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        7..8,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct A",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 15..29,
+                                    name: "B",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        22..23,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "M::C",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 42..60,
+                                    name: "C",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        53..54,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "pub struct C",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_return_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo() -> impl Foo {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_return_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S;
+fn foo() -> impl Foo<S> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..25,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_return_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+trait Bar {}
+fn foo() -> impl Foo + Bar {}
+
+fn main() { let s<|>t = foo(); }
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 13..25,
+                                    name: "Bar",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        19..22,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_return_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+trait Bar<T> {}
+struct S1 {}
+struct S2 {}
+
+fn foo() -> impl Foo<S1> + Bar<S2> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..31,
+                                    name: "Bar",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        22..25,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S1",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 32..44,
+                                    name: "S1",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        39..41,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S1",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S2",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 45..57,
+                                    name: "S2",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        52..54,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S2",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo(ar<|>g: &impl Foo) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_impl_traits_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+trait Bar<T> {}
+struct S{}
+
+fn foo(ar<|>g: &impl Foo + Bar<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Bar",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 13..28,
+                                    name: "Bar",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        19..22,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Bar",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 29..39,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        36..37,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_arg_generic_impl_trait_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S {}
+fn foo(ar<|>g: &impl Foo<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..27,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_dyn_return_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+struct S;
+impl Foo for S {}
+
+struct B<T>{}
+fn foo() -> B<dyn Foo> {}
+
+fn main() { let s<|>t = foo(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 42..55,
+                                    name: "B",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        49..50,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_dyn_arg_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {}
+fn foo(ar<|>g: &dyn Foo) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..12,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_generic_dyn_arg_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo<T> {}
+struct S {}
+fn foo(ar<|>g: &dyn Foo<S>) {}
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..15,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 16..27,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        23..24,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_goto_type_action_links_order() {
+        check_actions(
+            r#"
+trait ImplTrait<T> {}
+trait DynTrait<T> {}
+struct B<T> {}
+struct S {}
+
+fn foo(a<|>rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
+            "#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "ImplTrait",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..21,
+                                    name: "ImplTrait",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..15,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait ImplTrait",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "B",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 43..57,
+                                    name: "B",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        50..51,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct B",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "DynTrait",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 22..42,
+                                    name: "DynTrait",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        28..36,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait DynTrait",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                            HoverGotoTypeData {
+                                mod_path: "S",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 58..69,
+                                    name: "S",
+                                    kind: STRUCT_DEF,
+                                    focus_range: Some(
+                                        65..66,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "struct S",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn test_hover_associated_type_has_goto_type_action() {
+        check_actions(
+            r#"
+trait Foo {
+    type Item;
+    fn get(self) -> Self::Item {}
+}
 
-            fn my() {}
-            ",
-            &["mod my"],
+struct Bar{}
+struct S{}
+
+impl Foo for S { type Item = Bar; }
+
+fn test() -> impl Foo { S {} }
+
+fn main() { let s<|>t = test().get(); }
+"#,
+            expect![[r#"
+                [
+                    GoToType(
+                        [
+                            HoverGotoTypeData {
+                                mod_path: "Foo",
+                                nav: NavigationTarget {
+                                    file_id: FileId(
+                                        1,
+                                    ),
+                                    full_range: 0..62,
+                                    name: "Foo",
+                                    kind: TRAIT_DEF,
+                                    focus_range: Some(
+                                        6..9,
+                                    ),
+                                    container_name: None,
+                                    description: Some(
+                                        "trait Foo",
+                                    ),
+                                    docs: None,
+                                },
+                            },
+                        ],
+                    ),
+                ]
+            "#]],
         );
     }
 }
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 75bd3c96b..3cbae8a45 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -3,7 +3,7 @@ use ra_ide_db::RootDatabase;
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, ArgListOwner, AstNode, TypeAscriptionOwner},
-    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange,
+    match_ast, Direction, NodeOrToken, SmolStr, SyntaxKind, TextRange, T,
 };
 
 use crate::{FileId, FunctionSignature};
@@ -112,7 +112,7 @@ fn get_chaining_hints(
     // Ignoring extra whitespace and comments
     let next = tokens.next()?.kind();
     let next_next = tokens.next()?.kind();
-    if next == SyntaxKind::WHITESPACE && next_next == SyntaxKind::DOT {
+    if next == SyntaxKind::WHITESPACE && next_next == T![.] {
         let ty = sema.type_of_expr(&expr)?;
         if ty.is_unknown() {
             return None;
@@ -149,11 +149,10 @@ fn get_param_name_hints(
         ast::Expr::MethodCallExpr(expr) => expr.arg_list()?.args(),
         _ => return None,
     };
-    let args_count = args.clone().count();
 
     let fn_signature = get_fn_signature(sema, &expr)?;
     let n_params_to_skip =
-        if fn_signature.has_self_param && fn_signature.parameter_names.len() > args_count {
+        if fn_signature.has_self_param && matches!(&expr, ast::Expr::MethodCallExpr(_)) {
             1
         } else {
             0
@@ -259,6 +258,7 @@ fn should_show_param_name_hint(
     if param_name.is_empty()
         || Some(param_name) == fn_signature.name.as_ref().map(|s| s.trim_start_matches('_'))
         || is_argument_similar_to_param_name(sema, argument, param_name)
+        || param_name.starts_with("ra_fixture")
     {
         return false;
     }
@@ -271,7 +271,7 @@ fn should_show_param_name_hint(
 
     // avoid displaying hints for common functions like map, filter, etc.
     // or other obvious words used in std
-    parameters_len != 1 || !is_obvious_param(param_name)
+    !(parameters_len == 1 && is_obvious_param(param_name))
 }
 
 fn is_argument_similar_to_param_name(
@@ -313,10 +313,8 @@ fn get_string_representation(expr: &ast::Expr) -> Option<String> {
 }
 
 fn is_obvious_param(param_name: &str) -> bool {
-    let is_obvious_param_name = match param_name {
-        "predicate" | "value" | "pat" | "rhs" | "other" => true,
-        _ => false,
-    };
+    let is_obvious_param_name =
+        matches!(param_name, "predicate" | "value" | "pat" | "rhs" | "other");
     param_name.len() == 1 || is_obvious_param_name
 }
 
@@ -326,13 +324,13 @@ fn get_fn_signature(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<
             // FIXME: Type::as_callable is broken for closures
             let callable_def = sema.type_of_expr(&expr.expr()?)?.as_callable()?;
             match callable_def {
-                hir::CallableDef::FunctionId(it) => {
+                hir::CallableDefId::FunctionId(it) => {
                     Some(FunctionSignature::from_hir(sema.db, it.into()))
                 }
-                hir::CallableDef::StructId(it) => {
+                hir::CallableDefId::StructId(it) => {
                     FunctionSignature::from_struct(sema.db, it.into())
                 }
-                hir::CallableDef::EnumVariantId(it) => {
+                hir::CallableDefId::EnumVariantId(it) => {
                     FunctionSignature::from_enum_variant(sema.db, it.into())
                 }
             }
@@ -347,581 +345,252 @@ fn get_fn_signature(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<
 
 #[cfg(test)]
 mod tests {
-    use crate::inlay_hints::InlayHintsConfig;
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
+    use test_utils::extract_annotations;
+
+    use crate::{inlay_hints::InlayHintsConfig, mock_analysis::single_file};
 
-    use crate::mock_analysis::single_file;
+    fn check(ra_fixture: &str) {
+        check_with_config(InlayHintsConfig::default(), ra_fixture);
+    }
+
+    fn check_with_config(config: InlayHintsConfig, ra_fixture: &str) {
+        let (analysis, file_id) = single_file(ra_fixture);
+        let expected = extract_annotations(&*analysis.file_text(file_id).unwrap());
+        let inlay_hints = analysis.inlay_hints(file_id, &config).unwrap();
+        let actual =
+            inlay_hints.into_iter().map(|it| (it.range, it.label.to_string())).collect::<Vec<_>>();
+        assert_eq!(expected, actual);
+    }
+
+    fn check_expect(config: InlayHintsConfig, ra_fixture: &str, expect: Expect) {
+        let (analysis, file_id) = single_file(ra_fixture);
+        let inlay_hints = analysis.inlay_hints(file_id, &config).unwrap();
+        expect.assert_debug_eq(&inlay_hints)
+    }
 
     #[test]
     fn param_hints_only() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig {
+                parameter_hints: true,
+                type_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
             r#"
-            fn foo(a: i32, b: i32) -> i32 { a + b }
-            fn main() {
-                let _x = foo(4, 4);
-            }"#,
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(
+        4,
+      //^ a
+        4,
+      //^ b
+    );
+}"#,
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ parameter_hints: true, type_hints: false, chaining_hints: false, max_length: None}).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 106..107,
-                kind: ParameterHint,
-                label: "a",
-            },
-            InlayHint {
-                range: 109..110,
-                kind: ParameterHint,
-                label: "b",
-            },
-        ]"###);
     }
 
     #[test]
     fn hints_disabled() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: false,
+                parameter_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
             r#"
-            fn foo(a: i32, b: i32) -> i32 { a + b }
-            fn main() {
-                let _x = foo(4, 4);
-            }"#,
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(4, 4);
+}"#,
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ type_hints: false, parameter_hints: false, chaining_hints: false, max_length: None}).unwrap(), @r###"[]"###);
     }
 
     #[test]
     fn type_hints_only() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: true,
+                parameter_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
             r#"
-            fn foo(a: i32, b: i32) -> i32 { a + b }
-            fn main() {
-                let _x = foo(4, 4);
-            }"#,
+fn foo(a: i32, b: i32) -> i32 { a + b }
+fn main() {
+    let _x = foo(4, 4);
+      //^^ i32
+}"#,
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ type_hints: true, parameter_hints: false, chaining_hints: false, max_length: None}).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 97..99,
-                kind: TypeHint,
-                label: "i32",
-            },
-        ]"###);
     }
+
     #[test]
     fn default_generic_types_should_not_be_displayed() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
-struct Test<K, T = u8> {
-    k: K,
-    t: T,
-}
+struct Test<K, T = u8> { k: K, t: T }
 
 fn main() {
-    let zz = Test { t: 23, k: 33 };
+    let zz = Test { t: 23u8, k: 33 };
+      //^^ Test<i32>
     let zz_ref = &zz;
+      //^^^^^^ &Test<i32>
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 69..71,
-                kind: TypeHint,
-                label: "Test<i32>",
-            },
-            InlayHint {
-                range: 105..111,
-                kind: TypeHint,
-                label: "&Test<i32>",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn let_statement() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
 #[derive(PartialEq)]
-enum CustomOption<T> {
-    None,
-    Some(T),
-}
+enum Option<T> { None, Some(T) }
 
 #[derive(PartialEq)]
-struct Test {
-    a: CustomOption<u32>,
-    b: u8,
-}
+struct Test { a: Option<u32>, b: u8 }
 
 fn main() {
     struct InnerStruct {}
 
     let test = 54;
+      //^^^^ i32
     let test: i32 = 33;
     let mut test = 33;
+      //^^^^^^^^ i32
     let _ = 22;
     let test = "test";
+      //^^^^ &str
     let test = InnerStruct {};
 
-    let test = vec![222];
-    let test: Vec<_> = (0..3).collect();
-    let test = (0..3).collect::<Vec<i128>>();
-    let test = (0..3).collect::<Vec<_>>();
-
-    let mut test = Vec::new();
-    test.push(333);
+    let test = unresolved();
 
     let test = (42, 'a');
-    let (a, (b, c, (d, e), f)) = (2, (3, 4, (6.6, 7.7), 5));
+      //^^^^ (i32, char)
+    let (a,    (b,     (c,)) = (2, (3, (9.2,));
+       //^ i32  ^ i32   ^ f64
     let &x = &92;
+       //^ i32
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 193..197,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 236..244,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 275..279,
-                kind: TypeHint,
-                label: "&str",
-            },
-            InlayHint {
-                range: 539..543,
-                kind: TypeHint,
-                label: "(i32, char)",
-            },
-            InlayHint {
-                range: 566..567,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 570..571,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 573..574,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 577..578,
-                kind: TypeHint,
-                label: "f64",
-            },
-            InlayHint {
-                range: 580..581,
-                kind: TypeHint,
-                label: "f64",
-            },
-            InlayHint {
-                range: 584..585,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 627..628,
-                kind: TypeHint,
-                label: "i32",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn closure_parameters() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
 fn main() {
     let mut start = 0;
-    (0..2).for_each(|increment| {
-        start += increment;
-    });
+      //^^^^^^^^^ i32
+    (0..2).for_each(|increment| { start += increment; });
+                   //^^^^^^^^^ i32
 
-    let multiply = |a, b, c, d| a * b * c * d;
-    let _: i32 = multiply(1, 2, 3, 4);
+    let multiply =
+      //^^^^^^^^ |…| -> i32
+      | a,     b| a * b
+      //^ i32  ^ i32
+    ;
+
+    let _: i32 = multiply(1, 2);
     let multiply_ref = &multiply;
+      //^^^^^^^^^^^^ &|…| -> i32
 
     let return_42 = || 42;
+      //^^^^^^^^^ || -> i32
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 21..30,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 57..66,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 115..123,
-                kind: TypeHint,
-                label: "|…| -> i32",
-            },
-            InlayHint {
-                range: 127..128,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 130..131,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 133..134,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 136..137,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 201..213,
-                kind: TypeHint,
-                label: "&|…| -> i32",
-            },
-            InlayHint {
-                range: 236..245,
-                kind: TypeHint,
-                label: "|| -> i32",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn for_expression() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
 fn main() {
     let mut start = 0;
-    for increment in 0..2 {
-        start += increment;
-    }
+      //^^^^^^^^^ i32
+    for increment in 0..2 { start += increment; }
+      //^^^^^^^^^ i32
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 21..30,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 44..53,
-                kind: TypeHint,
-                label: "i32",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn if_expr() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
-#[derive(PartialEq)]
-enum CustomOption<T> {
-    None,
-    Some(T),
-}
-
-#[derive(PartialEq)]
-struct Test {
-    a: CustomOption<u32>,
-    b: u8,
-}
+enum Option<T> { None, Some(T) }
+use Option::*;
 
-use CustomOption::*;
+struct Test { a: Option<u32>, b: u8 }
 
 fn main() {
     let test = Some(Test { a: Some(3), b: 1 });
+      //^^^^ Option<Test>
     if let None = &test {};
     if let test = &test {};
+         //^^^^ &Option<Test>
     if let Some(test) = &test {};
-    if let Some(Test { a, b }) = &test {};
-    if let Some(Test { a: x, b: y }) = &test {};
-    if let Some(Test { a: Some(x), b: y }) = &test {};
-    if let Some(Test { a: None, b: y }) = &test {};
+              //^^^^ &Test
+    if let Some(Test { a,             b }) = &test {};
+                     //^ &Option<u32> ^ &u8
+    if let Some(Test { a: x,             b: y }) = &test {};
+                        //^ &Option<u32>    ^ &u8
+    if let Some(Test { a: Some(x),  b: y }) = &test {};
+                             //^ &u32  ^ &u8
+    if let Some(Test { a: None,  b: y }) = &test {};
+                                  //^ &u8
     if let Some(Test { b: y, .. }) = &test {};
-
+                        //^ &u8
     if test == None {}
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 188..192,
-                kind: TypeHint,
-                label: "CustomOption<Test>",
-            },
-            InlayHint {
-                range: 267..271,
-                kind: TypeHint,
-                label: "&CustomOption<Test>",
-            },
-            InlayHint {
-                range: 300..304,
-                kind: TypeHint,
-                label: "&Test",
-            },
-            InlayHint {
-                range: 341..342,
-                kind: TypeHint,
-                label: "&CustomOption<u32>",
-            },
-            InlayHint {
-                range: 344..345,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 387..388,
-                kind: TypeHint,
-                label: "&CustomOption<u32>",
-            },
-            InlayHint {
-                range: 393..394,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 441..442,
-                kind: TypeHint,
-                label: "&u32",
-            },
-            InlayHint {
-                range: 448..449,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 500..501,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 543..544,
-                kind: TypeHint,
-                label: "&u8",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn while_expr() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
-#[derive(PartialEq)]
-enum CustomOption<T> {
-    None,
-    Some(T),
-}
+enum Option<T> { None, Some(T) }
+use Option::*;
 
-#[derive(PartialEq)]
-struct Test {
-    a: CustomOption<u32>,
-    b: u8,
-}
-
-use CustomOption::*;
+struct Test { a: Option<u32>, b: u8 }
 
 fn main() {
     let test = Some(Test { a: Some(3), b: 1 });
-    while let None = &test {};
-    while let test = &test {};
-    while let Some(test) = &test {};
-    while let Some(Test { a, b }) = &test {};
-    while let Some(Test { a: x, b: y }) = &test {};
-    while let Some(Test { a: Some(x), b: y }) = &test {};
-    while let Some(Test { a: None, b: y }) = &test {};
-    while let Some(Test { b: y, .. }) = &test {};
-
-    while test == None {}
+      //^^^^ Option<Test>
+    while let Some(Test { a: Some(x),  b: y }) = &test {};
+                                //^ &u32  ^ &u8
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 188..192,
-                kind: TypeHint,
-                label: "CustomOption<Test>",
-            },
-            InlayHint {
-                range: 273..277,
-                kind: TypeHint,
-                label: "&CustomOption<Test>",
-            },
-            InlayHint {
-                range: 309..313,
-                kind: TypeHint,
-                label: "&Test",
-            },
-            InlayHint {
-                range: 353..354,
-                kind: TypeHint,
-                label: "&CustomOption<u32>",
-            },
-            InlayHint {
-                range: 356..357,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 402..403,
-                kind: TypeHint,
-                label: "&CustomOption<u32>",
-            },
-            InlayHint {
-                range: 408..409,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 459..460,
-                kind: TypeHint,
-                label: "&u32",
-            },
-            InlayHint {
-                range: 466..467,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 521..522,
-                kind: TypeHint,
-                label: "&u8",
-            },
-            InlayHint {
-                range: 567..568,
-                kind: TypeHint,
-                label: "&u8",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn match_arm_list() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
-#[derive(PartialEq)]
-enum CustomOption<T> {
-    None,
-    Some(T),
-}
-
-#[derive(PartialEq)]
-struct Test {
-    a: CustomOption<u32>,
-    b: u8,
-}
+enum Option<T> { None, Some(T) }
+use Option::*;
 
-use CustomOption::*;
+struct Test { a: Option<u32>, b: u8 }
 
 fn main() {
     match Some(Test { a: Some(3), b: 1 }) {
         None => (),
         test => (),
-        Some(test) => (),
-        Some(Test { a, b }) => (),
-        Some(Test { a: x, b: y }) => (),
+      //^^^^ Option<Test>
         Some(Test { a: Some(x), b: y }) => (),
-        Some(Test { a: None, b: y }) => (),
-        Some(Test { b: y, .. }) => (),
+                          //^ u32  ^ u8
         _ => {}
     }
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 252..256,
-                kind: TypeHint,
-                label: "CustomOption<Test>",
-            },
-            InlayHint {
-                range: 277..281,
-                kind: TypeHint,
-                label: "Test",
-            },
-            InlayHint {
-                range: 310..311,
-                kind: TypeHint,
-                label: "CustomOption<u32>",
-            },
-            InlayHint {
-                range: 313..314,
-                kind: TypeHint,
-                label: "u8",
-            },
-            InlayHint {
-                range: 348..349,
-                kind: TypeHint,
-                label: "CustomOption<u32>",
-            },
-            InlayHint {
-                range: 354..355,
-                kind: TypeHint,
-                label: "u8",
-            },
-            InlayHint {
-                range: 394..395,
-                kind: TypeHint,
-                label: "u32",
-            },
-            InlayHint {
-                range: 401..402,
-                kind: TypeHint,
-                label: "u8",
-            },
-            InlayHint {
-                range: 445..446,
-                kind: TypeHint,
-                label: "u8",
-            },
-            InlayHint {
-                range: 480..481,
-                kind: TypeHint,
-                label: "u8",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn hint_truncation() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
             r#"
 struct Smol<T>(T);
 
@@ -929,52 +598,25 @@ struct VeryLongOuterName<T>(T);
 
 fn main() {
     let a = Smol(0u32);
+      //^ Smol<u32>
     let b = VeryLongOuterName(0usize);
+      //^ VeryLongOuterName<…>
     let c = Smol(Smol(0u32))
+      //^ Smol<Smol<…>>
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 74..75,
-                kind: TypeHint,
-                label: "Smol<u32>",
-            },
-            InlayHint {
-                range: 98..99,
-                kind: TypeHint,
-                label: "VeryLongOuterName<…>",
-            },
-            InlayHint {
-                range: 137..138,
-                kind: TypeHint,
-                label: "Smol<Smol<…>>",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn function_call_parameter_hint() {
-        let (analysis, file_id) = single_file(
+        check(
             r#"
-enum CustomOption<T> {
-    None,
-    Some(T),
-}
-use CustomOption::*;
+enum Option<T> { None, Some(T) }
+use Option::*;
 
 struct FileId {}
 struct SmolStr {}
 
-impl From<&str> for SmolStr {
-    fn from(_: &str) -> Self {
-        unimplemented!()
-    }
-}
-
 struct TextRange {}
 struct SyntaxKind {}
 struct NavigationTarget {}
@@ -982,18 +624,15 @@ struct NavigationTarget {}
 struct Test {}
 
 impl Test {
-    fn method(&self, mut param: i32) -> i32 {
-        param * 2
-    }
+    fn method(&self, mut param: i32) -> i32 { param * 2 }
 
     fn from_syntax(
         file_id: FileId,
         name: SmolStr,
-        focus_range: CustomOption<TextRange>,
+        focus_range: Option<TextRange>,
         full_range: TextRange,
         kind: SyntaxKind,
-        docs: CustomOption<String>,
-        description: CustomOption<String>,
+        docs: Option<String>,
     ) -> NavigationTarget {
         NavigationTarget {}
     }
@@ -1005,108 +644,36 @@ fn test_func(mut foo: i32, bar: i32, msg: &str, _: i32, last: i32) -> i32 {
 
 fn main() {
     let not_literal = 1;
-    let _: i32 = test_func(1, 2, "hello", 3, not_literal);
+      //^^^^^^^^^^^ i32
+    let _: i32 = test_func(1,    2,      "hello", 3,  not_literal);
+                         //^ foo ^ bar   ^^^^^^^ msg  ^^^^^^^^^^^ last
     let t: Test = Test {};
     t.method(123);
-    Test::method(&t, 3456);
-
+           //^^^ param
+    Test::method(&t,      3456);
+               //^^ &self ^^^^ param
     Test::from_syntax(
         FileId {},
+      //^^^^^^^^^ file_id
         "impl".into(),
+      //^^^^^^^^^^^^^ name
         None,
+      //^^^^ focus_range
         TextRange {},
+      //^^^^^^^^^^^^ full_range
         SyntaxKind {},
+      //^^^^^^^^^^^^^ kind
         None,
-        None,
+      //^^^^ docs
     );
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig::default()).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 798..809,
-                kind: TypeHint,
-                label: "i32",
-            },
-            InlayHint {
-                range: 842..843,
-                kind: ParameterHint,
-                label: "foo",
-            },
-            InlayHint {
-                range: 845..846,
-                kind: ParameterHint,
-                label: "bar",
-            },
-            InlayHint {
-                range: 848..855,
-                kind: ParameterHint,
-                label: "msg",
-            },
-            InlayHint {
-                range: 860..871,
-                kind: ParameterHint,
-                label: "last",
-            },
-            InlayHint {
-                range: 914..917,
-                kind: ParameterHint,
-                label: "param",
-            },
-            InlayHint {
-                range: 937..939,
-                kind: ParameterHint,
-                label: "&self",
-            },
-            InlayHint {
-                range: 941..945,
-                kind: ParameterHint,
-                label: "param",
-            },
-            InlayHint {
-                range: 980..989,
-                kind: ParameterHint,
-                label: "file_id",
-            },
-            InlayHint {
-                range: 999..1012,
-                kind: ParameterHint,
-                label: "name",
-            },
-            InlayHint {
-                range: 1022..1026,
-                kind: ParameterHint,
-                label: "focus_range",
-            },
-            InlayHint {
-                range: 1036..1048,
-                kind: ParameterHint,
-                label: "full_range",
-            },
-            InlayHint {
-                range: 1058..1071,
-                kind: ParameterHint,
-                label: "kind",
-            },
-            InlayHint {
-                range: 1081..1085,
-                kind: ParameterHint,
-                label: "docs",
-            },
-            InlayHint {
-                range: 1095..1099,
-                kind: ParameterHint,
-                label: "description",
-            },
-        ]
-        "###
-        );
     }
 
     #[test]
     fn omitted_parameters_hints_heuristics() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
             r#"
 fn map(f: i32) {}
 fn filter(predicate: i32) {}
@@ -1188,22 +755,15 @@ fn main() {
     let _: f64 = a.abs_sub(b);
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
-        []
-        "###
-        );
     }
 
     #[test]
     fn unit_structs_have_no_type_hints() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig { max_length: Some(8), ..Default::default() },
             r#"
-enum CustomResult<T, E> {
-    Ok(T),
-    Err(E),
-}
-use CustomResult::*;
+enum Result<T, E> { Ok(T), Err(E) }
+use Result::*;
 
 struct SyntheticSyntax;
 
@@ -1214,133 +774,155 @@ fn main() {
     }
 }"#,
         );
-
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig { max_length: Some(8), ..Default::default() }).unwrap(), @r###"
-        []
-        "###
-        );
     }
 
     #[test]
     fn chaining_hints_ignore_comments() {
-        let (analysis, file_id) = single_file(
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
             r#"
-            struct A(B);
-            impl A { fn into_b(self) -> B { self.0 } }
-            struct B(C);
-            impl B { fn into_c(self) -> C { self.0 } }
-            struct C;
-
-            fn main() {
-                let c = A(B(C))
-                    .into_b() // This is a comment
-                    .into_c();
-            }"#,
+struct A(B);
+impl A { fn into_b(self) -> B { self.0 } }
+struct B(C);
+impl B { fn into_c(self) -> C { self.0 } }
+struct C;
+
+fn main() {
+    let c = A(B(C))
+        .into_b() // This is a comment
+        .into_c();
+}
+"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 147..172,
+                        kind: ChainingHint,
+                        label: "B",
+                    },
+                    InlayHint {
+                        range: 147..154,
+                        kind: ChainingHint,
+                        label: "A",
+                    },
+                ]
+            "#]],
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None}).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 232..269,
-                kind: ChainingHint,
-                label: "B",
-            },
-            InlayHint {
-                range: 232..239,
-                kind: ChainingHint,
-                label: "A",
-            },
-        ]"###);
     }
 
     #[test]
     fn chaining_hints_without_newlines() {
-        let (analysis, file_id) = single_file(
+        check_with_config(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
             r#"
-            struct A(B);
-            impl A { fn into_b(self) -> B { self.0 } }
-            struct B(C);
-            impl B { fn into_c(self) -> C { self.0 } }
-            struct C;
-
-            fn main() {
-                let c = A(B(C)).into_b().into_c();
-            }"#,
+struct A(B);
+impl A { fn into_b(self) -> B { self.0 } }
+struct B(C);
+impl B { fn into_c(self) -> C { self.0 } }
+struct C;
+
+fn main() {
+    let c = A(B(C)).into_b().into_c();
+}"#,
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None}).unwrap(), @r###"[]"###);
     }
 
     #[test]
     fn struct_access_chaining_hints() {
-        let (analysis, file_id) = single_file(
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
             r#"
-            struct A { pub b: B }
-            struct B { pub c: C }
-            struct C(pub bool);
-            struct D;
+struct A { pub b: B }
+struct B { pub c: C }
+struct C(pub bool);
+struct D;
 
-            impl D {
-                fn foo(&self) -> i32 { 42 }
-            }
+impl D {
+    fn foo(&self) -> i32 { 42 }
+}
 
-            fn main() {
-                let x = A { b: B { c: C(true) } }
-                    .b
-                    .c
-                    .0;
-                let x = D
-                    .foo();
-            }"#,
+fn main() {
+    let x = A { b: B { c: C(true) } }
+        .b
+        .c
+        .0;
+    let x = D
+        .foo();
+}"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 143..190,
+                        kind: ChainingHint,
+                        label: "C",
+                    },
+                    InlayHint {
+                        range: 143..179,
+                        kind: ChainingHint,
+                        label: "B",
+                    },
+                ]
+            "#]],
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None}).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 252..323,
-                kind: ChainingHint,
-                label: "C",
-            },
-            InlayHint {
-                range: 252..300,
-                kind: ChainingHint,
-                label: "B",
-            },
-        ]
-        "###);
     }
 
     #[test]
     fn generic_chaining_hints() {
-        let (analysis, file_id) = single_file(
+        check_expect(
+            InlayHintsConfig {
+                parameter_hints: false,
+                type_hints: false,
+                chaining_hints: true,
+                max_length: None,
+            },
             r#"
-            struct A<T>(T);
-            struct B<T>(T);
-            struct C<T>(T);
-            struct X<T,R>(T, R);
-
-            impl<T> A<T> {
-                fn new(t: T) -> Self { A(t) }
-                fn into_b(self) -> B<T> { B(self.0) }
-            }
-            impl<T> B<T> {
-                fn into_c(self) -> C<T> { C(self.0) }
-            }
-            fn main() {
-                let c = A::new(X(42, true))
-                    .into_b()
-                    .into_c();
-            }"#,
+struct A<T>(T);
+struct B<T>(T);
+struct C<T>(T);
+struct X<T,R>(T, R);
+
+impl<T> A<T> {
+    fn new(t: T) -> Self { A(t) }
+    fn into_b(self) -> B<T> { B(self.0) }
+}
+impl<T> B<T> {
+    fn into_c(self) -> C<T> { C(self.0) }
+}
+fn main() {
+    let c = A::new(X(42, true))
+        .into_b()
+        .into_c();
+}
+"#,
+            expect![[r#"
+                [
+                    InlayHint {
+                        range: 246..283,
+                        kind: ChainingHint,
+                        label: "B<X<i32, bool>>",
+                    },
+                    InlayHint {
+                        range: 246..265,
+                        kind: ChainingHint,
+                        label: "A<X<i32, bool>>",
+                    },
+                ]
+            "#]],
         );
-        assert_debug_snapshot!(analysis.inlay_hints(file_id, &InlayHintsConfig{ parameter_hints: false, type_hints: false, chaining_hints: true, max_length: None}).unwrap(), @r###"
-        [
-            InlayHint {
-                range: 403..452,
-                kind: ChainingHint,
-                label: "B<X<i32, bool>>",
-            },
-            InlayHint {
-                range: 403..422,
-                kind: ChainingHint,
-                label: "A<X<i32, bool>>",
-            },
-        ]"###);
     }
 }
diff --git a/crates/ra_ide/src/join_lines.rs b/crates/ra_ide/src/join_lines.rs
index 5036c1fb0..6907c09e8 100644
--- a/crates/ra_ide/src/join_lines.rs
+++ b/crates/ra_ide/src/join_lines.rs
@@ -165,10 +165,7 @@ fn join_single_use_tree(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Opti
 }
 
 fn is_trailing_comma(left: SyntaxKind, right: SyntaxKind) -> bool {
-    match (left, right) {
-        (T![,], T![')']) | (T![,], T![']']) => true,
-        _ => false,
-    }
+    matches!((left, right), (T![,], T![')']) | (T![,], T![']']))
 }
 
 #[cfg(test)]
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 12d5716e8..5d1f64e19 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -17,6 +17,7 @@ macro_rules! eprintln {
 
 pub mod mock_analysis;
 
+mod markup;
 mod prime_caches;
 mod status;
 mod completion;
@@ -47,7 +48,7 @@ use std::sync::Arc;
 use ra_cfg::CfgOptions;
 use ra_db::{
     salsa::{self, ParallelDatabase},
-    CheckCanceled, Env, FileLoader, SourceDatabase,
+    CheckCanceled, Env, FileLoader, FileSet, SourceDatabase, VfsPath,
 };
 use ra_ide_db::{
     symbol_index::{self, FileSymbol},
@@ -59,6 +60,7 @@ use crate::display::ToNav;
 
 pub use crate::{
     call_hierarchy::CallItem,
+    call_info::CallInfo,
     completion::{
         CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, InsertTextFormat,
     },
@@ -66,29 +68,31 @@ pub use crate::{
     display::{file_structure, FunctionSignature, NavigationTarget, StructureNode},
     expand_macro::ExpandedMacro,
     folding_ranges::{Fold, FoldKind},
-    hover::HoverResult,
+    hover::{HoverAction, HoverConfig, HoverGotoTypeData, HoverResult},
     inlay_hints::{InlayHint, InlayHintsConfig, InlayKind},
+    markup::Markup,
     references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
     runnables::{Runnable, RunnableKind, TestId},
-    ssr::SsrError,
     syntax_highlighting::{
         Highlight, HighlightModifier, HighlightModifiers, HighlightTag, HighlightedRange,
     },
 };
 
-pub use hir::Documentation;
-pub use ra_assists::{AssistConfig, AssistId};
+pub use hir::{Documentation, Semantics};
+pub use ra_assists::{Assist, AssistConfig, AssistId, AssistKind, ResolvedAssist};
 pub use ra_db::{
-    Canceled, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRootId,
+    Canceled, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRoot,
+    SourceRootId,
 };
 pub use ra_ide_db::{
-    change::{AnalysisChange, LibraryData},
+    change::AnalysisChange,
     line_index::{LineCol, LineIndex},
     search::SearchScope,
     source_change::{FileSystemEdit, SourceChange, SourceFileEdit},
     symbol_index::Query,
     RootDatabase,
 };
+pub use ra_ssr::SsrError;
 pub use ra_text_edit::{Indel, TextEdit};
 
 pub type Cancelable<T> = Result<T, Canceled>;
@@ -128,28 +132,12 @@ impl<T> RangeInfo<T> {
     }
 }
 
-/// Contains information about a call site. Specifically the
-/// `FunctionSignature`and current parameter.
-#[derive(Debug)]
-pub struct CallInfo {
-    pub signature: FunctionSignature,
-    pub active_parameter: Option<usize>,
-}
-
 /// `AnalysisHost` stores the current state of the world.
 #[derive(Debug)]
 pub struct AnalysisHost {
     db: RootDatabase,
 }
 
-#[derive(Debug)]
-pub struct Assist {
-    pub id: AssistId,
-    pub label: String,
-    pub group_label: Option<String>,
-    pub source_change: SourceChange,
-}
-
 impl AnalysisHost {
     pub fn new(lru_capacity: Option<usize>) -> AnalysisHost {
         AnalysisHost { db: RootDatabase::new(lru_capacity) }
@@ -220,11 +208,14 @@ impl Analysis {
     // `AnalysisHost` for creating a fully-featured analysis.
     pub fn from_single_file(text: String) -> (Analysis, FileId) {
         let mut host = AnalysisHost::default();
-        let source_root = SourceRootId(0);
+        let file_id = FileId(0);
+        let mut file_set = FileSet::default();
+        file_set.insert(file_id, VfsPath::new_virtual_path("/main.rs".to_string()));
+        let source_root = SourceRoot::new_local(file_set);
+
         let mut change = AnalysisChange::new();
-        change.add_root(source_root, true);
+        change.set_roots(vec![source_root]);
         let mut crate_graph = CrateGraph::default();
-        let file_id = FileId(0);
         // FIXME: cfg options
         // Default to enable test for single file.
         let mut cfg_options = CfgOptions::default();
@@ -236,9 +227,8 @@ impl Analysis {
             cfg_options,
             Env::default(),
             Default::default(),
-            Default::default(),
         );
-        change.add_file(source_root, file_id, "main.rs".into(), Arc::new(text));
+        change.change_file(file_id, Some(Arc::new(text)));
         change.set_crate_graph(crate_graph);
         host.apply_change(change);
         (host.analysis(), file_id)
@@ -390,7 +380,9 @@ impl Analysis {
         position: FilePosition,
         search_scope: Option<SearchScope>,
     ) -> Cancelable<Option<ReferenceSearchResult>> {
-        self.with_db(|db| references::find_all_refs(db, position, search_scope).map(|it| it.info))
+        self.with_db(|db| {
+            references::find_all_refs(&Semantics::new(db), position, search_scope).map(|it| it.info)
+        })
     }
 
     /// Returns a short text describing element at position.
@@ -448,12 +440,14 @@ impl Analysis {
 
     /// Computes syntax highlighting for the given file
     pub fn highlight(&self, file_id: FileId) -> Cancelable<Vec<HighlightedRange>> {
-        self.with_db(|db| syntax_highlighting::highlight(db, file_id, None))
+        self.with_db(|db| syntax_highlighting::highlight(db, file_id, None, false))
     }
 
     /// Computes syntax highlighting for the given file range.
     pub fn highlight_range(&self, frange: FileRange) -> Cancelable<Vec<HighlightedRange>> {
-        self.with_db(|db| syntax_highlighting::highlight(db, frange.file_id, Some(frange.range)))
+        self.with_db(|db| {
+            syntax_highlighting::highlight(db, frange.file_id, Some(frange.range), false)
+        })
     }
 
     /// Computes syntax highlighting for the given file.
@@ -470,20 +464,23 @@ impl Analysis {
         self.with_db(|db| completion::completions(db, config, position).map(Into::into))
     }
 
-    /// Computes assists (aka code actions aka intentions) for the given
+    /// Computes resolved assists with source changes for the given position.
+    pub fn resolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<ResolvedAssist>> {
+        self.with_db(|db| ra_assists::Assist::resolved(db, config, frange))
+    }
+
+    /// Computes unresolved assists (aka code actions aka intentions) for the given
     /// position.
-    pub fn assists(&self, config: &AssistConfig, frange: FileRange) -> Cancelable<Vec<Assist>> {
-        self.with_db(|db| {
-            ra_assists::Assist::resolved(db, config, frange)
-                .into_iter()
-                .map(|assist| Assist {
-                    id: assist.assist.id,
-                    label: assist.assist.label,
-                    group_label: assist.assist.group.map(|it| it.0),
-                    source_change: assist.source_change,
-                })
-                .collect()
-        })
+    pub fn unresolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<Assist>> {
+        self.with_db(|db| Assist::unresolved(db, config, frange))
     }
 
     /// Computes the set of diagnostics for the given file.
@@ -508,7 +505,7 @@ impl Analysis {
     ) -> Cancelable<Result<SourceChange, SsrError>> {
         self.with_db(|db| {
             let edits = ssr::parse_search_replace(query, parse_only, db)?;
-            Ok(SourceChange::source_file_edits(edits))
+            Ok(SourceChange::from(edits))
         })
     }
 
diff --git a/crates/ra_ide/src/markup.rs b/crates/ra_ide/src/markup.rs
new file mode 100644
index 000000000..60c193c40
--- /dev/null
+++ b/crates/ra_ide/src/markup.rs
@@ -0,0 +1,38 @@
+//! Markdown formatting.
+//!
+//! Sometimes, we want to display a "rich text" in the UI. At the moment, we use
+//! markdown for this purpose. It doesn't feel like a right option, but that's
+//! what is used by LSP, so let's keep it simple.
+use std::fmt;
+
+#[derive(Default, Debug)]
+pub struct Markup {
+    text: String,
+}
+
+impl From<Markup> for String {
+    fn from(markup: Markup) -> Self {
+        markup.text
+    }
+}
+
+impl From<String> for Markup {
+    fn from(text: String) -> Self {
+        Markup { text }
+    }
+}
+
+impl fmt::Display for Markup {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.text, f)
+    }
+}
+
+impl Markup {
+    pub fn as_str(&self) -> &str {
+        self.text.as_str()
+    }
+    pub fn fenced_block(contents: &impl fmt::Display) -> Markup {
+        format!("```rust\n{}\n```", contents).into()
+    }
+}
diff --git a/crates/ra_ide/src/matching_brace.rs b/crates/ra_ide/src/matching_brace.rs
index 407a9636d..742d70c9c 100644
--- a/crates/ra_ide/src/matching_brace.rs
+++ b/crates/ra_ide/src/matching_brace.rs
@@ -1,8 +1,12 @@
-use ra_syntax::{ast::AstNode, SourceFile, SyntaxKind, TextSize, T};
+use ra_syntax::{
+    ast::{self, AstNode},
+    SourceFile, SyntaxKind, TextSize, T,
+};
+use test_utils::mark;
 
 // Feature: Matching Brace
 //
-// If the cursor is on any brace (`<>(){}[]`) which is a part of a brace-pair,
+// If the cursor is on any brace (`<>(){}[]||`) which is a part of a brace-pair,
 // moves cursor to the matching brace. It uses the actual parser to determine
 // braces, so it won't confuse generics with comparisons.
 //
@@ -13,8 +17,8 @@ use ra_syntax::{ast::AstNode, SourceFile, SyntaxKind, TextSize, T};
 // |===
 pub fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<TextSize> {
     const BRACES: &[SyntaxKind] =
-        &[T!['{'], T!['}'], T!['['], T![']'], T!['('], T![')'], T![<], T![>]];
-    let (brace_node, brace_idx) = file
+        &[T!['{'], T!['}'], T!['['], T![']'], T!['('], T![')'], T![<], T![>], T![|], T![|]];
+    let (brace_token, brace_idx) = file
         .syntax()
         .token_at_offset(offset)
         .filter_map(|node| {
@@ -22,9 +26,16 @@ pub fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<TextSize> {
             Some((node, idx))
         })
         .next()?;
-    let parent = brace_node.parent();
+    let parent = brace_token.parent();
+    if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
+        mark::hit!(pipes_not_braces);
+        return None;
+    }
     let matching_kind = BRACES[brace_idx ^ 1];
-    let matching_node = parent.children_with_tokens().find(|node| node.kind() == matching_kind)?;
+    let matching_node = parent
+        .children_with_tokens()
+        .filter_map(|it| it.into_token())
+        .find(|node| node.kind() == matching_kind && node != &brace_token)?;
     Some(matching_node.text_range().start())
 }
 
@@ -48,5 +59,15 @@ mod tests {
         }
 
         do_check("struct Foo { a: i32, }<|>", "struct Foo <|>{ a: i32, }");
+        do_check("fn main() { |x: i32|<|> x * 2;}", "fn main() { <|>|x: i32| x * 2;}");
+        do_check("fn main() { <|>|x: i32| x * 2;}", "fn main() { |x: i32<|>| x * 2;}");
+
+        {
+            mark::check!(pipes_not_braces);
+            do_check(
+                "fn main() { match 92 { 1 | 2 |<|> 3 => 92 } }",
+                "fn main() { match 92 { 1 | 2 |<|> 3 => 92 } }",
+            );
+        }
     }
 }
diff --git a/crates/ra_ide/src/mock_analysis.rs b/crates/ra_ide/src/mock_analysis.rs
index ad78d2d93..b28054688 100644
--- a/crates/ra_ide/src/mock_analysis.rs
+++ b/crates/ra_ide/src/mock_analysis.rs
@@ -1,87 +1,24 @@
 //! FIXME: write short doc here
-
-use std::str::FromStr;
 use std::sync::Arc;
 
 use ra_cfg::CfgOptions;
-use ra_db::{CrateName, Env, RelativePathBuf};
-use test_utils::{extract_offset, extract_range, parse_fixture, FixtureEntry, CURSOR_MARKER};
+use ra_db::{CrateName, Env, FileSet, SourceRoot, VfsPath};
+use test_utils::{
+    extract_annotations, extract_range_or_offset, Fixture, RangeOrOffset, CURSOR_MARKER,
+};
 
 use crate::{
     Analysis, AnalysisChange, AnalysisHost, CrateGraph, Edition, FileId, FilePosition, FileRange,
-    SourceRootId,
 };
 
-#[derive(Debug)]
-enum MockFileData {
-    Plain { path: String, content: String },
-    Fixture(FixtureEntry),
-}
-
-impl MockFileData {
-    fn new(path: String, content: String) -> Self {
-        // `Self::Plain` causes a false warning: 'variant is never constructed: `Plain` '
-        // see https://github.com/rust-lang/rust/issues/69018
-        MockFileData::Plain { path, content }
-    }
-
-    fn path(&self) -> &str {
-        match self {
-            MockFileData::Plain { path, .. } => path.as_str(),
-            MockFileData::Fixture(f) => f.meta.path().as_str(),
-        }
-    }
-
-    fn content(&self) -> &str {
-        match self {
-            MockFileData::Plain { content, .. } => content,
-            MockFileData::Fixture(f) => f.text.as_str(),
-        }
-    }
-
-    fn cfg_options(&self) -> CfgOptions {
-        match self {
-            MockFileData::Fixture(f) => {
-                f.meta.cfg_options().map_or_else(Default::default, |o| o.clone())
-            }
-            _ => CfgOptions::default(),
-        }
-    }
-
-    fn edition(&self) -> Edition {
-        match self {
-            MockFileData::Fixture(f) => {
-                f.meta.edition().map_or(Edition::Edition2018, |v| Edition::from_str(v).unwrap())
-            }
-            _ => Edition::Edition2018,
-        }
-    }
-
-    fn env(&self) -> Env {
-        match self {
-            MockFileData::Fixture(f) => Env::from(f.meta.env()),
-            _ => Env::default(),
-        }
-    }
-}
-
-impl From<FixtureEntry> for MockFileData {
-    fn from(fixture: FixtureEntry) -> Self {
-        Self::Fixture(fixture)
-    }
-}
-
 /// Mock analysis is used in test to bootstrap an AnalysisHost/Analysis
 /// from a set of in-memory files.
 #[derive(Debug, Default)]
 pub struct MockAnalysis {
-    files: Vec<MockFileData>,
+    files: Vec<Fixture>,
 }
 
 impl MockAnalysis {
-    pub fn new() -> MockAnalysis {
-        MockAnalysis::default()
-    }
     /// Creates `MockAnalysis` using a fixture data in the following format:
     ///
     /// ```not_rust
@@ -92,106 +29,107 @@ impl MockAnalysis {
     /// //- /foo.rs
     /// struct Baz;
     /// ```
-    pub fn with_files(fixture: &str) -> MockAnalysis {
-        let mut res = MockAnalysis::new();
-        for entry in parse_fixture(fixture) {
-            res.add_file_fixture(entry);
-        }
+    pub fn with_files(ra_fixture: &str) -> MockAnalysis {
+        let (res, pos) = MockAnalysis::with_fixture(ra_fixture);
+        assert!(pos.is_none());
         res
     }
 
     /// Same as `with_files`, but requires that a single file contains a `<|>` marker,
     /// whose position is also returned.
     pub fn with_files_and_position(fixture: &str) -> (MockAnalysis, FilePosition) {
+        let (res, position) = MockAnalysis::with_fixture(fixture);
+        let (file_id, range_or_offset) = position.expect("expected a marker (<|>)");
+        let offset = match range_or_offset {
+            RangeOrOffset::Range(_) => panic!(),
+            RangeOrOffset::Offset(it) => it,
+        };
+        (res, FilePosition { file_id, offset })
+    }
+
+    fn with_fixture(fixture: &str) -> (MockAnalysis, Option<(FileId, RangeOrOffset)>) {
         let mut position = None;
-        let mut res = MockAnalysis::new();
-        for entry in parse_fixture(fixture) {
+        let mut res = MockAnalysis::default();
+        for mut entry in Fixture::parse(fixture) {
             if entry.text.contains(CURSOR_MARKER) {
                 assert!(position.is_none(), "only one marker (<|>) per fixture is allowed");
-                position = Some(res.add_file_fixture_with_position(entry));
+                let (range_or_offset, text) = extract_range_or_offset(&entry.text);
+                entry.text = text;
+                let file_id = res.add_file_fixture(entry);
+                position = Some((file_id, range_or_offset));
             } else {
                 res.add_file_fixture(entry);
             }
         }
-        let position = position.expect("expected a marker (<|>)");
         (res, position)
     }
 
-    pub fn add_file_fixture(&mut self, fixture: FixtureEntry) -> FileId {
-        let file_id = self.next_id();
-        self.files.push(MockFileData::from(fixture));
+    fn add_file_fixture(&mut self, fixture: Fixture) -> FileId {
+        let file_id = FileId((self.files.len() + 1) as u32);
+        self.files.push(fixture);
         file_id
     }
 
-    pub fn add_file_fixture_with_position(&mut self, mut fixture: FixtureEntry) -> FilePosition {
-        let (offset, text) = extract_offset(&fixture.text);
-        fixture.text = text;
-        let file_id = self.next_id();
-        self.files.push(MockFileData::from(fixture));
-        FilePosition { file_id, offset }
-    }
-
-    pub fn add_file(&mut self, path: &str, text: &str) -> FileId {
-        let file_id = self.next_id();
-        self.files.push(MockFileData::new(path.to_string(), text.to_string()));
+    pub fn id_of(&self, path: &str) -> FileId {
+        let (file_id, _) =
+            self.files().find(|(_, data)| path == data.path).expect("no file in this mock");
         file_id
     }
-    pub fn add_file_with_position(&mut self, path: &str, text: &str) -> FilePosition {
-        let (offset, text) = extract_offset(text);
-        let file_id = self.next_id();
-        self.files.push(MockFileData::new(path.to_string(), text));
-        FilePosition { file_id, offset }
+    pub fn annotations(&self) -> Vec<(FileRange, String)> {
+        self.files()
+            .flat_map(|(file_id, fixture)| {
+                let annotations = extract_annotations(&fixture.text);
+                annotations
+                    .into_iter()
+                    .map(move |(range, data)| (FileRange { file_id, range }, data))
+            })
+            .collect()
     }
-    pub fn add_file_with_range(&mut self, path: &str, text: &str) -> FileRange {
-        let (range, text) = extract_range(text);
-        let file_id = self.next_id();
-        self.files.push(MockFileData::new(path.to_string(), text));
-        FileRange { file_id, range }
+    pub fn files(&self) -> impl Iterator<Item = (FileId, &Fixture)> + '_ {
+        self.files.iter().enumerate().map(|(idx, fixture)| (FileId(idx as u32 + 1), fixture))
     }
-    pub fn id_of(&self, path: &str) -> FileId {
-        let (idx, _) = self
-            .files
-            .iter()
-            .enumerate()
-            .find(|(_, data)| path == data.path())
-            .expect("no file in this mock");
-        FileId(idx as u32 + 1)
+    pub fn annotation(&self) -> (FileRange, String) {
+        let mut all = self.annotations();
+        assert_eq!(all.len(), 1);
+        all.pop().unwrap()
     }
     pub fn analysis_host(self) -> AnalysisHost {
         let mut host = AnalysisHost::default();
-        let source_root = SourceRootId(0);
         let mut change = AnalysisChange::new();
-        change.add_root(source_root, true);
+        let mut file_set = FileSet::default();
         let mut crate_graph = CrateGraph::default();
         let mut root_crate = None;
         for (i, data) in self.files.into_iter().enumerate() {
-            let path = data.path();
+            let path = data.path;
             assert!(path.starts_with('/'));
-            let path = RelativePathBuf::from_path(&path[1..]).unwrap();
-            let cfg_options = data.cfg_options();
+
+            let mut cfg = CfgOptions::default();
+            data.cfg_atoms.iter().for_each(|it| cfg.insert_atom(it.into()));
+            data.cfg_key_values.iter().for_each(|(k, v)| cfg.insert_key_value(k.into(), v.into()));
+            let edition: Edition =
+                data.edition.and_then(|it| it.parse().ok()).unwrap_or(Edition::Edition2018);
+
             let file_id = FileId(i as u32 + 1);
-            let edition = data.edition();
-            let env = data.env();
+            let env = Env::from(data.env.iter());
             if path == "/lib.rs" || path == "/main.rs" {
                 root_crate = Some(crate_graph.add_crate_root(
                     file_id,
                     edition,
                     None,
-                    cfg_options,
+                    cfg,
                     env,
                     Default::default(),
-                    Default::default(),
                 ));
             } else if path.ends_with("/lib.rs") {
-                let crate_name = path.parent().unwrap().file_name().unwrap();
+                let base = &path[..path.len() - "/lib.rs".len()];
+                let crate_name = &base[base.rfind('/').unwrap() + '/'.len_utf8()..];
                 let other_crate = crate_graph.add_crate_root(
                     file_id,
                     edition,
-                    Some(CrateName::new(crate_name).unwrap()),
-                    cfg_options,
+                    Some(crate_name.to_string()),
+                    cfg,
                     env,
                     Default::default(),
-                    Default::default(),
                 );
                 if let Some(root_crate) = root_crate {
                     crate_graph
@@ -199,19 +137,18 @@ impl MockAnalysis {
                         .unwrap();
                 }
             }
-            change.add_file(source_root, file_id, path, Arc::new(data.content().to_owned()));
+            let path = VfsPath::new_virtual_path(path.to_string());
+            file_set.insert(file_id, path);
+            change.change_file(file_id, Some(Arc::new(data.text).to_owned()));
         }
         change.set_crate_graph(crate_graph);
+        change.set_roots(vec![SourceRoot::new_local(file_set)]);
         host.apply_change(change);
         host
     }
     pub fn analysis(self) -> Analysis {
         self.analysis_host().analysis()
     }
-
-    fn next_id(&self) -> FileId {
-        FileId((self.files.len() + 1) as u32)
-    }
 }
 
 /// Creates analysis from a multi-file fixture, returns positions marked with <|>.
@@ -222,21 +159,18 @@ pub fn analysis_and_position(ra_fixture: &str) -> (Analysis, FilePosition) {
 
 /// Creates analysis for a single file.
 pub fn single_file(ra_fixture: &str) -> (Analysis, FileId) {
-    let mut mock = MockAnalysis::new();
-    let file_id = mock.add_file("/main.rs", ra_fixture);
+    let mock = MockAnalysis::with_files(ra_fixture);
+    let file_id = mock.id_of("/main.rs");
     (mock.analysis(), file_id)
 }
 
-/// Creates analysis for a single file, returns position marked with <|>.
-pub fn single_file_with_position(ra_fixture: &str) -> (Analysis, FilePosition) {
-    let mut mock = MockAnalysis::new();
-    let pos = mock.add_file_with_position("/main.rs", ra_fixture);
-    (mock.analysis(), pos)
-}
-
 /// Creates analysis for a single file, returns range marked with a pair of <|>.
-pub fn single_file_with_range(ra_fixture: &str) -> (Analysis, FileRange) {
-    let mut mock = MockAnalysis::new();
-    let pos = mock.add_file_with_range("/main.rs", ra_fixture);
-    (mock.analysis(), pos)
+pub fn analysis_and_range(ra_fixture: &str) -> (Analysis, FileRange) {
+    let (res, position) = MockAnalysis::with_fixture(ra_fixture);
+    let (file_id, range_or_offset) = position.expect("expected a marker (<|>)");
+    let range = match range_or_offset {
+        RangeOrOffset::Range(it) => it,
+        RangeOrOffset::Offset(_) => panic!(),
+    };
+    (res.analysis(), FileRange { file_id, range })
 }
diff --git a/crates/ra_ide/src/parent_module.rs b/crates/ra_ide/src/parent_module.rs
index fa1535da5..e3e0c7639 100644
--- a/crates/ra_ide/src/parent_module.rs
+++ b/crates/ra_ide/src/parent_module.rs
@@ -125,12 +125,12 @@ mod tests {
     #[test]
     fn test_resolve_crate_root() {
         let mock = MockAnalysis::with_files(
-            "
-        //- /bar.rs
-        mod foo;
-        //- /foo.rs
-        // empty <|>
-    ",
+            r#"
+//- /bar.rs
+mod foo;
+//- /foo.rs
+// empty
+"#,
         );
         let root_file = mock.id_of("/bar.rs");
         let mod_file = mock.id_of("/foo.rs");
@@ -145,7 +145,6 @@ mod tests {
             CfgOptions::default(),
             Env::default(),
             Default::default(),
-            Default::default(),
         );
         let mut change = AnalysisChange::new();
         change.set_crate_graph(crate_graph);
diff --git a/crates/ra_ide/src/prime_caches.rs b/crates/ra_ide/src/prime_caches.rs
index 90bf7d25f..c5ab5a1d8 100644
--- a/crates/ra_ide/src/prime_caches.rs
+++ b/crates/ra_ide/src/prime_caches.rs
@@ -7,6 +7,6 @@ use crate::{FileId, RootDatabase};
 
 pub(crate) fn prime_caches(db: &RootDatabase, files: Vec<FileId>) {
     for file in files {
-        let _ = crate::syntax_highlighting::highlight(db, file, None);
+        let _ = crate::syntax_highlighting::highlight(db, file, None, false);
     }
 }
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index bb40d2043..c2b0d5efe 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -86,12 +86,11 @@ impl IntoIterator for ReferenceSearchResult {
 }
 
 pub(crate) fn find_all_refs(
-    db: &RootDatabase,
+    sema: &Semantics<RootDatabase>,
     position: FilePosition,
     search_scope: Option<SearchScope>,
 ) -> Option<RangeInfo<ReferenceSearchResult>> {
     let _p = profile("find_all_refs");
-    let sema = Semantics::new(db);
     let syntax = sema.parse(position.file_id).syntax().clone();
 
     let (opt_name, search_kind) = if let Some(name) =
@@ -108,15 +107,15 @@ pub(crate) fn find_all_refs(
     let RangeInfo { range, info: def } = find_name(&sema, &syntax, position, opt_name)?;
 
     let references = def
-        .find_usages(db, search_scope)
+        .find_usages(sema, search_scope)
         .into_iter()
         .filter(|r| search_kind == ReferenceKind::Other || search_kind == r.kind)
         .collect();
 
-    let decl_range = def.try_to_nav(db)?.range();
+    let decl_range = def.try_to_nav(sema.db)?.range();
 
     let declaration = Declaration {
-        nav: def.try_to_nav(db)?,
+        nav: def.try_to_nav(sema.db)?,
         kind: ReferenceKind::Other,
         access: decl_access(&def, &syntax, decl_range),
     };
@@ -191,244 +190,249 @@ fn get_struct_def_name_for_struct_literal_search(
 #[cfg(test)]
 mod tests {
     use crate::{
-        mock_analysis::{analysis_and_position, single_file_with_position, MockAnalysis},
+        mock_analysis::{analysis_and_position, MockAnalysis},
         Declaration, Reference, ReferenceSearchResult, SearchScope,
     };
 
     #[test]
     fn test_struct_literal_after_space() {
-        let code = r#"
-    struct Foo <|>{
-        a: i32,
-    }
-    impl Foo {
-        fn f() -> i32 { 42 }
-    }
-    fn main() {
-        let f: Foo;
-        f = Foo {a: Foo::f()};
-    }"#;
-
-        let refs = get_all_refs(code);
+        let refs = get_all_refs(
+            r#"
+struct Foo <|>{
+    a: i32,
+}
+impl Foo {
+    fn f() -> i32 { 42 }
+}
+fn main() {
+    let f: Foo;
+    f = Foo {a: Foo::f()};
+}
+"#,
+        );
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(1) 5..39 12..15 Other",
-            &["FileId(1) 138..141 StructLiteral"],
+            "Foo STRUCT_DEF FileId(1) 0..26 7..10 Other",
+            &["FileId(1) 101..104 StructLiteral"],
         );
     }
 
     #[test]
-    fn test_struct_literal_befor_space() {
-        let code = r#"
-    struct Foo<|> {}
-        fn main() {
-        let f: Foo;
-        f = Foo {};
-    }"#;
-
-        let refs = get_all_refs(code);
+    fn test_struct_literal_before_space() {
+        let refs = get_all_refs(
+            r#"
+struct Foo<|> {}
+    fn main() {
+    let f: Foo;
+    f = Foo {};
+}
+"#,
+        );
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(1) 5..18 12..15 Other",
-            &["FileId(1) 54..57 Other", "FileId(1) 71..74 StructLiteral"],
+            "Foo STRUCT_DEF FileId(1) 0..13 7..10 Other",
+            &["FileId(1) 41..44 Other", "FileId(1) 54..57 StructLiteral"],
         );
     }
 
     #[test]
     fn test_struct_literal_with_generic_type() {
-        let code = r#"
-    struct Foo<T> <|>{}
-        fn main() {
-        let f: Foo::<i32>;
-        f = Foo {};
-    }"#;
-
-        let refs = get_all_refs(code);
+        let refs = get_all_refs(
+            r#"
+struct Foo<T> <|>{}
+    fn main() {
+    let f: Foo::<i32>;
+    f = Foo {};
+}
+"#,
+        );
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(1) 5..21 12..15 Other",
-            &["FileId(1) 81..84 StructLiteral"],
+            "Foo STRUCT_DEF FileId(1) 0..16 7..10 Other",
+            &["FileId(1) 64..67 StructLiteral"],
         );
     }
 
     #[test]
     fn test_struct_literal_for_tuple() {
-        let code = r#"
-    struct Foo<|>(i32);
+        let refs = get_all_refs(
+            r#"
+struct Foo<|>(i32);
 
-    fn main() {
-        let f: Foo;
-        f = Foo(1);
-    }"#;
-
-        let refs = get_all_refs(code);
+fn main() {
+    let f: Foo;
+    f = Foo(1);
+}
+"#,
+        );
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(1) 5..21 12..15 Other",
-            &["FileId(1) 71..74 StructLiteral"],
+            "Foo STRUCT_DEF FileId(1) 0..16 7..10 Other",
+            &["FileId(1) 54..57 StructLiteral"],
         );
     }
 
     #[test]
     fn test_find_all_refs_for_local() {
-        let code = r#"
-    fn main() {
-        let mut i = 1;
-        let j = 1;
-        i = i<|> + j;
+        let refs = get_all_refs(
+            r#"
+fn main() {
+    let mut i = 1;
+    let j = 1;
+    i = i<|> + j;
 
-        {
-            i = 0;
-        }
-
-        i = 5;
-    }"#;
+    {
+        i = 0;
+    }
 
-        let refs = get_all_refs(code);
+    i = 5;
+}"#,
+        );
         check_result(
             refs,
-            "i BIND_PAT FileId(1) 33..34 Other Write",
+            "i BIND_PAT FileId(1) 24..25 Other Write",
             &[
-                "FileId(1) 67..68 Other Write",
-                "FileId(1) 71..72 Other Read",
-                "FileId(1) 101..102 Other Write",
-                "FileId(1) 127..128 Other Write",
+                "FileId(1) 50..51 Other Write",
+                "FileId(1) 54..55 Other Read",
+                "FileId(1) 76..77 Other Write",
+                "FileId(1) 94..95 Other Write",
             ],
         );
     }
 
     #[test]
     fn search_filters_by_range() {
-        let code = r#"
-            fn foo() {
-                let spam<|> = 92;
-                spam + spam
-            }
-            fn bar() {
-                let spam = 92;
-                spam + spam
-            }
-        "#;
-        let refs = get_all_refs(code);
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let spam<|> = 92;
+    spam + spam
+}
+fn bar() {
+    let spam = 92;
+    spam + spam
+}
+"#,
+        );
         check_result(
             refs,
-            "spam BIND_PAT FileId(1) 44..48 Other",
-            &["FileId(1) 71..75 Other Read", "FileId(1) 78..82 Other Read"],
+            "spam BIND_PAT FileId(1) 19..23 Other",
+            &["FileId(1) 34..38 Other Read", "FileId(1) 41..45 Other Read"],
         );
     }
 
     #[test]
     fn test_find_all_refs_for_param_inside() {
-        let code = r#"
-    fn foo(i : u32) -> u32 {
-        i<|>
-    }"#;
-
-        let refs = get_all_refs(code);
-        check_result(refs, "i BIND_PAT FileId(1) 12..13 Other", &["FileId(1) 38..39 Other Read"]);
+        let refs = get_all_refs(
+            r#"
+fn foo(i : u32) -> u32 {
+    i<|>
+}
+"#,
+        );
+        check_result(refs, "i BIND_PAT FileId(1) 7..8 Other", &["FileId(1) 29..30 Other Read"]);
     }
 
     #[test]
     fn test_find_all_refs_for_fn_param() {
-        let code = r#"
-    fn foo(i<|> : u32) -> u32 {
-        i
-    }"#;
-
-        let refs = get_all_refs(code);
-        check_result(refs, "i BIND_PAT FileId(1) 12..13 Other", &["FileId(1) 38..39 Other Read"]);
+        let refs = get_all_refs(
+            r#"
+fn foo(i<|> : u32) -> u32 {
+    i
+}
+"#,
+        );
+        check_result(refs, "i BIND_PAT FileId(1) 7..8 Other", &["FileId(1) 29..30 Other Read"]);
     }
 
     #[test]
     fn test_find_all_refs_field_name() {
-        let code = r#"
-            //- /lib.rs
-            struct Foo {
-                pub spam<|>: u32,
-            }
-
-            fn main(s: Foo) {
-                let f = s.spam;
-            }
-        "#;
+        let refs = get_all_refs(
+            r#"
+//- /lib.rs
+struct Foo {
+    pub spam<|>: u32,
+}
 
-        let refs = get_all_refs(code);
+fn main(s: Foo) {
+    let f = s.spam;
+}
+"#,
+        );
         check_result(
             refs,
-            "spam RECORD_FIELD_DEF FileId(1) 66..79 70..74 Other",
-            &["FileId(1) 152..156 Other Read"],
+            "spam RECORD_FIELD_DEF FileId(1) 17..30 21..25 Other",
+            &["FileId(1) 67..71 Other Read"],
         );
     }
 
     #[test]
     fn test_find_all_refs_impl_item_name() {
-        let code = r#"
-            //- /lib.rs
-            struct Foo;
-            impl Foo {
-                fn f<|>(&self) {  }
-            }
-        "#;
-
-        let refs = get_all_refs(code);
-        check_result(refs, "f FN_DEF FileId(1) 88..104 91..92 Other", &[]);
+        let refs = get_all_refs(
+            r#"
+struct Foo;
+impl Foo {
+    fn f<|>(&self) {  }
+}
+"#,
+        );
+        check_result(refs, "f FN_DEF FileId(1) 27..43 30..31 Other", &[]);
     }
 
     #[test]
     fn test_find_all_refs_enum_var_name() {
-        let code = r#"
-            //- /lib.rs
-            enum Foo {
-                A,
-                B<|>,
-                C,
-            }
-        "#;
-
-        let refs = get_all_refs(code);
-        check_result(refs, "B ENUM_VARIANT FileId(1) 83..84 83..84 Other", &[]);
+        let refs = get_all_refs(
+            r#"
+enum Foo {
+    A,
+    B<|>,
+    C,
+}
+"#,
+        );
+        check_result(refs, "B ENUM_VARIANT FileId(1) 22..23 22..23 Other", &[]);
     }
 
     #[test]
     fn test_find_all_refs_two_modules() {
-        let code = r#"
-            //- /lib.rs
-            pub mod foo;
-            pub mod bar;
-
-            fn f() {
-                let i = foo::Foo { n: 5 };
-            }
-
-            //- /foo.rs
-            use crate::bar;
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+pub mod foo;
+pub mod bar;
+
+fn f() {
+    let i = foo::Foo { n: 5 };
+}
 
-            pub struct Foo {
-                pub n: u32,
-            }
+//- /foo.rs
+use crate::bar;
 
-            fn f() {
-                let i = bar::Bar { n: 5 };
-            }
+pub struct Foo {
+    pub n: u32,
+}
 
-            //- /bar.rs
-            use crate::foo;
+fn f() {
+    let i = bar::Bar { n: 5 };
+}
 
-            pub struct Bar {
-                pub n: u32,
-            }
+//- /bar.rs
+use crate::foo;
 
-            fn f() {
-                let i = foo::Foo<|> { n: 5 };
-            }
-        "#;
+pub struct Bar {
+    pub n: u32,
+}
 
-        let (analysis, pos) = analysis_and_position(code);
+fn f() {
+    let i = foo::Foo<|> { n: 5 };
+}
+"#,
+        );
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "Foo STRUCT_DEF FileId(2) 16..50 27..30 Other",
-            &["FileId(1) 52..55 StructLiteral", "FileId(3) 77..80 StructLiteral"],
+            "Foo STRUCT_DEF FileId(2) 17..51 28..31 Other",
+            &["FileId(1) 53..56 StructLiteral", "FileId(3) 79..82 StructLiteral"],
         );
     }
 
@@ -437,53 +441,53 @@ mod tests {
     // which is the whole `foo.rs`, and the second one is in `use foo::Foo`.
     #[test]
     fn test_find_all_refs_decl_module() {
-        let code = r#"
-            //- /lib.rs
-            mod foo<|>;
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+mod foo<|>;
 
-            use foo::Foo;
+use foo::Foo;
 
-            fn f() {
-                let i = Foo { n: 5 };
-            }
-
-            //- /foo.rs
-            pub struct Foo {
-                pub n: u32,
-            }
-        "#;
+fn f() {
+    let i = Foo { n: 5 };
+}
 
-        let (analysis, pos) = analysis_and_position(code);
+//- /foo.rs
+pub struct Foo {
+    pub n: u32,
+}
+"#,
+        );
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
-        check_result(refs, "foo SOURCE_FILE FileId(2) 0..35 Other", &["FileId(1) 13..16 Other"]);
+        check_result(refs, "foo SOURCE_FILE FileId(2) 0..35 Other", &["FileId(1) 14..17 Other"]);
     }
 
     #[test]
     fn test_find_all_refs_super_mod_vis() {
-        let code = r#"
-            //- /lib.rs
-            mod foo;
-
-            //- /foo.rs
-            mod some;
-            use some::Foo;
+        let (analysis, pos) = analysis_and_position(
+            r#"
+//- /lib.rs
+mod foo;
 
-            fn f() {
-                let i = Foo { n: 5 };
-            }
+//- /foo.rs
+mod some;
+use some::Foo;
 
-            //- /foo/some.rs
-            pub(super) struct Foo<|> {
-                pub n: u32,
-            }
-        "#;
+fn f() {
+    let i = Foo { n: 5 };
+}
 
-        let (analysis, pos) = analysis_and_position(code);
+//- /foo/some.rs
+pub(super) struct Foo<|> {
+    pub n: u32,
+}
+"#,
+        );
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
             "Foo STRUCT_DEF FileId(3) 0..41 18..21 Other",
-            &["FileId(2) 20..23 Other", "FileId(2) 46..49 StructLiteral"],
+            &["FileId(2) 20..23 Other", "FileId(2) 47..50 StructLiteral"],
         );
     }
 
@@ -510,7 +514,7 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "quux FN_DEF FileId(1) 18..34 25..29 Other",
+            "quux FN_DEF FileId(1) 19..35 26..30 Other",
             &["FileId(2) 16..20 StructLiteral", "FileId(3) 16..20 StructLiteral"],
         );
 
@@ -518,100 +522,105 @@ mod tests {
             analysis.find_all_refs(pos, Some(SearchScope::single_file(bar))).unwrap().unwrap();
         check_result(
             refs,
-            "quux FN_DEF FileId(1) 18..34 25..29 Other",
+            "quux FN_DEF FileId(1) 19..35 26..30 Other",
             &["FileId(3) 16..20 StructLiteral"],
         );
     }
 
     #[test]
     fn test_find_all_refs_macro_def() {
-        let code = r#"
-        #[macro_export]
-        macro_rules! m1<|> { () => (()) }
-
-        fn foo() {
-            m1();
-            m1();
-        }"#;
-
-        let refs = get_all_refs(code);
+        let refs = get_all_refs(
+            r#"
+#[macro_export]
+macro_rules! m1<|> { () => (()) }
+
+fn foo() {
+    m1();
+    m1();
+}
+"#,
+        );
         check_result(
             refs,
-            "m1 MACRO_CALL FileId(1) 9..63 46..48 Other",
-            &["FileId(1) 96..98 StructLiteral", "FileId(1) 114..116 StructLiteral"],
+            "m1 MACRO_CALL FileId(1) 0..46 29..31 Other",
+            &["FileId(1) 63..65 StructLiteral", "FileId(1) 73..75 StructLiteral"],
         );
     }
 
     #[test]
     fn test_basic_highlight_read_write() {
-        let code = r#"
-        fn foo() {
-            let mut i<|> = 0;
-            i = i + 1;
-        }"#;
-
-        let refs = get_all_refs(code);
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let mut i<|> = 0;
+    i = i + 1;
+}
+"#,
+        );
         check_result(
             refs,
-            "i BIND_PAT FileId(1) 40..41 Other Write",
-            &["FileId(1) 59..60 Other Write", "FileId(1) 63..64 Other Read"],
+            "i BIND_PAT FileId(1) 23..24 Other Write",
+            &["FileId(1) 34..35 Other Write", "FileId(1) 38..39 Other Read"],
         );
     }
 
     #[test]
     fn test_basic_highlight_field_read_write() {
-        let code = r#"
-        struct S {
-            f: u32,
-        }
-
-        fn foo() {
-            let mut s = S{f: 0};
-            s.f<|> = 0;
-        }"#;
+        let refs = get_all_refs(
+            r#"
+struct S {
+    f: u32,
+}
 
-        let refs = get_all_refs(code);
+fn foo() {
+    let mut s = S{f: 0};
+    s.f<|> = 0;
+}
+"#,
+        );
         check_result(
             refs,
-            "f RECORD_FIELD_DEF FileId(1) 32..38 32..33 Other",
-            &["FileId(1) 96..97 Other Read", "FileId(1) 117..118 Other Write"],
+            "f RECORD_FIELD_DEF FileId(1) 15..21 15..16 Other",
+            &["FileId(1) 55..56 Other Read", "FileId(1) 68..69 Other Write"],
         );
     }
 
     #[test]
     fn test_basic_highlight_decl_no_write() {
-        let code = r#"
-        fn foo() {
-            let i<|>;
-            i = 1;
-        }"#;
-
-        let refs = get_all_refs(code);
-        check_result(refs, "i BIND_PAT FileId(1) 36..37 Other", &["FileId(1) 51..52 Other Write"]);
+        let refs = get_all_refs(
+            r#"
+fn foo() {
+    let i<|>;
+    i = 1;
+}
+"#,
+        );
+        check_result(refs, "i BIND_PAT FileId(1) 19..20 Other", &["FileId(1) 26..27 Other Write"]);
     }
 
     #[test]
     fn test_find_struct_function_refs_outside_module() {
-        let code = r#"
-        mod foo {
-            pub struct Foo;
+        let refs = get_all_refs(
+            r#"
+mod foo {
+    pub struct Foo;
 
-            impl Foo {
-                pub fn new<|>() -> Foo {
-                    Foo
-                }
-            }
+    impl Foo {
+        pub fn new<|>() -> Foo {
+            Foo
         }
+    }
+}
 
-        fn main() {
-            let _f = foo::Foo::new();
-        }"#;
-
-        let refs = get_all_refs(code);
+fn main() {
+    let _f = foo::Foo::new();
+}
+"#,
+        );
         check_result(
             refs,
-            "new FN_DEF FileId(1) 87..150 94..97 Other",
-            &["FileId(1) 227..230 StructLiteral"],
+            "new FN_DEF FileId(1) 54..101 61..64 Other",
+            &["FileId(1) 146..149 StructLiteral"],
         );
     }
 
@@ -637,13 +646,13 @@ mod tests {
         let refs = analysis.find_all_refs(pos, None).unwrap().unwrap();
         check_result(
             refs,
-            "f FN_DEF FileId(1) 25..34 28..29 Other",
-            &["FileId(2) 11..12 Other", "FileId(2) 27..28 StructLiteral"],
+            "f FN_DEF FileId(1) 26..35 29..30 Other",
+            &["FileId(2) 11..12 Other", "FileId(2) 28..29 StructLiteral"],
         );
     }
 
-    fn get_all_refs(text: &str) -> ReferenceSearchResult {
-        let (analysis, position) = single_file_with_position(text);
+    fn get_all_refs(ra_fixture: &str) -> ReferenceSearchResult {
+        let (analysis, position) = analysis_and_position(ra_fixture);
         analysis.find_all_refs(position, None).unwrap().unwrap()
     }
 
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index 28c6349b1..8735ec53c 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -1,11 +1,14 @@
 //! FIXME: write short doc here
 
-use hir::{ModuleSource, Semantics};
-use ra_db::{RelativePath, RelativePathBuf, SourceDatabaseExt};
-use ra_ide_db::RootDatabase;
+use hir::{Module, ModuleDef, ModuleSource, Semantics};
+use ra_db::SourceDatabaseExt;
+use ra_ide_db::{
+    defs::{classify_name, classify_name_ref, Definition, NameClass, NameRefClass},
+    RootDatabase,
+};
 use ra_syntax::{
-    algo::find_node_at_offset, ast, ast::TypeAscriptionOwner, lex_single_valid_syntax_kind,
-    AstNode, SyntaxKind, SyntaxNode, SyntaxToken,
+    algo::find_node_at_offset, ast, ast::NameOwner, ast::TypeAscriptionOwner,
+    lex_single_valid_syntax_kind, match_ast, AstNode, SyntaxKind, SyntaxNode, SyntaxToken,
 };
 use ra_text_edit::TextEdit;
 use std::convert::TryInto;
@@ -21,35 +24,53 @@ pub(crate) fn rename(
     position: FilePosition,
     new_name: &str,
 ) -> Option<RangeInfo<SourceChange>> {
+    let sema = Semantics::new(db);
+
     match lex_single_valid_syntax_kind(new_name)? {
         SyntaxKind::IDENT | SyntaxKind::UNDERSCORE => (),
-        SyntaxKind::SELF_KW => return rename_to_self(db, position),
+        SyntaxKind::SELF_KW => return rename_to_self(&sema, position),
         _ => return None,
     }
 
-    let sema = Semantics::new(db);
     let source_file = sema.parse(position.file_id);
     let syntax = source_file.syntax();
-    if let Some((ast_name, ast_module)) = find_name_and_module_at_offset(syntax, position) {
-        let range = ast_name.syntax().text_range();
-        rename_mod(&sema, &ast_name, &ast_module, position, new_name)
-            .map(|info| RangeInfo::new(range, info))
+    if let Some(module) = find_module_at_offset(&sema, position, syntax) {
+        rename_mod(&sema, position, module, new_name)
     } else if let Some(self_token) =
         syntax.token_at_offset(position.offset).find(|t| t.kind() == SyntaxKind::SELF_KW)
     {
-        rename_self_to_param(db, position, self_token, new_name)
+        rename_self_to_param(&sema, position, self_token, new_name)
     } else {
-        rename_reference(sema.db, position, new_name)
+        rename_reference(&sema, position, new_name)
     }
 }
 
-fn find_name_and_module_at_offset(
-    syntax: &SyntaxNode,
+fn find_module_at_offset(
+    sema: &Semantics<RootDatabase>,
     position: FilePosition,
-) -> Option<(ast::Name, ast::Module)> {
-    let ast_name = find_node_at_offset::<ast::Name>(syntax, position.offset)?;
-    let ast_module = ast::Module::cast(ast_name.syntax().parent()?)?;
-    Some((ast_name, ast_module))
+    syntax: &SyntaxNode,
+) -> Option<Module> {
+    let ident = syntax.token_at_offset(position.offset).find(|t| t.kind() == SyntaxKind::IDENT)?;
+
+    let module = match_ast! {
+        match (ident.parent()) {
+            ast::NameRef(name_ref) => {
+                match classify_name_ref(sema, &name_ref)? {
+                    NameRefClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+                    _ => return None,
+                }
+            },
+            ast::Name(name) => {
+                match classify_name(&sema, &name)? {
+                    NameClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+                    _ => return None,
+                }
+            },
+            _ => return None,
+        }
+    };
+
+    Some(module)
 }
 
 fn source_edit_from_reference(reference: Reference, new_name: &str) -> SourceFileEdit {
@@ -78,61 +99,53 @@ fn source_edit_from_reference(reference: Reference, new_name: &str) -> SourceFil
 
 fn rename_mod(
     sema: &Semantics<RootDatabase>,
-    ast_name: &ast::Name,
-    ast_module: &ast::Module,
     position: FilePosition,
+    module: Module,
     new_name: &str,
-) -> Option<SourceChange> {
+) -> Option<RangeInfo<SourceChange>> {
     let mut source_file_edits = Vec::new();
     let mut file_system_edits = Vec::new();
-    if let Some(module) = sema.to_def(ast_module) {
-        let src = module.definition_source(sema.db);
-        let file_id = src.file_id.original_file(sema.db);
-        match src.value {
-            ModuleSource::SourceFile(..) => {
-                let mod_path: RelativePathBuf = sema.db.file_relative_path(file_id);
-                // mod is defined in path/to/dir/mod.rs
-                let dst_path = if mod_path.file_stem() == Some("mod") {
-                    mod_path
-                        .parent()
-                        .and_then(|p| p.parent())
-                        .or_else(|| Some(RelativePath::new("")))
-                        .map(|p| p.join(new_name).join("mod.rs"))
-                } else {
-                    Some(mod_path.with_file_name(new_name).with_extension("rs"))
-                };
-                if let Some(path) = dst_path {
-                    let move_file = FileSystemEdit::MoveFile {
-                        src: file_id,
-                        dst_source_root: sema.db.file_source_root(position.file_id),
-                        dst_path: path,
-                    };
-                    file_system_edits.push(move_file);
-                }
-            }
-            ModuleSource::Module(..) => {}
+
+    let src = module.definition_source(sema.db);
+    let file_id = src.file_id.original_file(sema.db);
+    match src.value {
+        ModuleSource::SourceFile(..) => {
+            // mod is defined in path/to/dir/mod.rs
+            let dst = if module.is_mod_rs(sema.db) {
+                format!("../{}/mod.rs", new_name)
+            } else {
+                format!("{}.rs", new_name)
+            };
+            let move_file = FileSystemEdit::MoveFile { src: file_id, anchor: file_id, dst };
+            file_system_edits.push(move_file);
         }
+        ModuleSource::Module(..) => {}
     }
 
-    let edit = SourceFileEdit {
-        file_id: position.file_id,
-        edit: TextEdit::replace(ast_name.syntax().text_range(), new_name.into()),
-    };
-    source_file_edits.push(edit);
-
-    if let Some(RangeInfo { range: _, info: refs }) = find_all_refs(sema.db, position, None) {
-        let ref_edits = refs
-            .references
-            .into_iter()
-            .map(|reference| source_edit_from_reference(reference, new_name));
-        source_file_edits.extend(ref_edits);
+    if let Some(src) = module.declaration_source(sema.db) {
+        let file_id = src.file_id.original_file(sema.db);
+        let name = src.value.name()?;
+        let edit = SourceFileEdit {
+            file_id,
+            edit: TextEdit::replace(name.syntax().text_range(), new_name.into()),
+        };
+        source_file_edits.push(edit);
     }
 
-    Some(SourceChange::from_edits(source_file_edits, file_system_edits))
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
+    let ref_edits = refs
+        .references
+        .into_iter()
+        .map(|reference| source_edit_from_reference(reference, new_name));
+    source_file_edits.extend(ref_edits);
+
+    Some(RangeInfo::new(range, SourceChange::from_edits(source_file_edits, file_system_edits)))
 }
 
-fn rename_to_self(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo<SourceChange>> {
-    let sema = Semantics::new(db);
+fn rename_to_self(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+) -> Option<RangeInfo<SourceChange>> {
     let source_file = sema.parse(position.file_id);
     let syn = source_file.syntax();
 
@@ -147,7 +160,7 @@ fn rename_to_self(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo
         _ => return None, // not renaming other types
     };
 
-    let RangeInfo { range, info: refs } = find_all_refs(db, position, None)?;
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
 
     let param_range = first_param.syntax().text_range();
     let (param_ref, usages): (Vec<Reference>, Vec<Reference>) = refs
@@ -171,7 +184,7 @@ fn rename_to_self(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo
         ),
     });
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edits)))
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn text_edit_from_self_param(
@@ -199,16 +212,15 @@ fn text_edit_from_self_param(
 }
 
 fn rename_self_to_param(
-    db: &RootDatabase,
+    sema: &Semantics<RootDatabase>,
     position: FilePosition,
     self_token: SyntaxToken,
     new_name: &str,
 ) -> Option<RangeInfo<SourceChange>> {
-    let sema = Semantics::new(db);
     let source_file = sema.parse(position.file_id);
     let syn = source_file.syntax();
 
-    let text = db.file_text(position.file_id);
+    let text = sema.db.file_text(position.file_id);
     let fn_def = find_node_at_offset::<ast::FnDef>(syn, position.offset)?;
     let search_range = fn_def.syntax().text_range();
 
@@ -234,15 +246,15 @@ fn rename_self_to_param(
     let range = ast::SelfParam::cast(self_token.parent())
         .map_or(self_token.text_range(), |p| p.syntax().text_range());
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edits)))
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn rename_reference(
-    db: &RootDatabase,
+    sema: &Semantics<RootDatabase>,
     position: FilePosition,
     new_name: &str,
 ) -> Option<RangeInfo<SourceChange>> {
-    let RangeInfo { range, info: refs } = find_all_refs(db, position, None)?;
+    let RangeInfo { range, info: refs } = find_all_refs(sema, position, None)?;
 
     let edit = refs
         .into_iter()
@@ -253,57 +265,56 @@ fn rename_reference(
         return None;
     }
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edit)))
+    Some(RangeInfo::new(range, SourceChange::from(edit)))
 }
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
     use ra_text_edit::TextEditBuilder;
+    use stdx::trim_indent;
     use test_utils::{assert_eq_text, mark};
 
-    use crate::{
-        mock_analysis::analysis_and_position, mock_analysis::single_file_with_position, FileId,
-    };
+    use crate::{mock_analysis::analysis_and_position, FileId};
+
+    fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
+        let (analysis, position) = analysis_and_position(ra_fixture_before);
+        let source_change = analysis.rename(position, new_name).unwrap();
+        let mut text_edit_builder = TextEditBuilder::default();
+        let mut file_id: Option<FileId> = None;
+        if let Some(change) = source_change {
+            for edit in change.info.source_file_edits {
+                file_id = Some(edit.file_id);
+                for indel in edit.edit.into_iter() {
+                    text_edit_builder.replace(indel.delete, indel.insert);
+                }
+            }
+        }
+        let mut result = analysis.file_text(file_id.unwrap()).unwrap().to_string();
+        text_edit_builder.finish().apply(&mut result);
+        assert_eq_text!(ra_fixture_after, &*result);
+    }
+
+    fn check_expect(new_name: &str, ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let source_change = analysis.rename(position, new_name).unwrap().unwrap();
+        expect.assert_debug_eq(&source_change)
+    }
 
     #[test]
     fn test_rename_to_underscore() {
-        test_rename(
-            r#"
-    fn main() {
-        let i<|> = 1;
-    }"#,
-            "_",
-            r#"
-    fn main() {
-        let _ = 1;
-    }"#,
-        );
+        check("_", r#"fn main() { let i<|> = 1; }"#, r#"fn main() { let _ = 1; }"#);
     }
 
     #[test]
     fn test_rename_to_raw_identifier() {
-        test_rename(
-            r#"
-    fn main() {
-        let i<|> = 1;
-    }"#,
-            "r#fn",
-            r#"
-    fn main() {
-        let r#fn = 1;
-    }"#,
-        );
+        check("r#fn", r#"fn main() { let i<|> = 1; }"#, r#"fn main() { let r#fn = 1; }"#);
     }
 
     #[test]
     fn test_rename_to_invalid_identifier() {
-        let (analysis, position) = single_file_with_position(
-            "
-    fn main() {
-        let i<|> = 1;
-    }",
-        );
+        let (analysis, position) = analysis_and_position(r#"fn main() { let i<|> = 1; }"#);
         let new_name = "invalid!";
         let source_change = analysis.rename(position, new_name).unwrap();
         assert!(source_change.is_none());
@@ -311,682 +322,689 @@ mod tests {
 
     #[test]
     fn test_rename_for_local() {
-        test_rename(
+        check(
+            "k",
             r#"
-    fn main() {
-        let mut i = 1;
-        let j = 1;
-        i = i<|> + j;
+fn main() {
+    let mut i = 1;
+    let j = 1;
+    i = i<|> + j;
 
-        {
-            i = 0;
-        }
+    { i = 0; }
 
-        i = 5;
-    }"#,
-            "k",
+    i = 5;
+}
+"#,
             r#"
-    fn main() {
-        let mut k = 1;
-        let j = 1;
-        k = k + j;
+fn main() {
+    let mut k = 1;
+    let j = 1;
+    k = k + j;
 
-        {
-            k = 0;
-        }
+    { k = 0; }
 
-        k = 5;
-    }"#,
+    k = 5;
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_for_macro_args() {
-        test_rename(
-            r#"
-    macro_rules! foo {($i:ident) => {$i} }
-    fn main() {
-        let a<|> = "test";
-        foo!(a);
-    }"#,
+        check(
             "b",
             r#"
-    macro_rules! foo {($i:ident) => {$i} }
-    fn main() {
-        let b = "test";
-        foo!(b);
-    }"#,
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a<|> = "test";
+    foo!(a);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_for_macro_args_rev() {
-        test_rename(
-            r#"
-    macro_rules! foo {($i:ident) => {$i} }
-    fn main() {
-        let a = "test";
-        foo!(a<|>);
-    }"#,
+        check(
             "b",
             r#"
-    macro_rules! foo {($i:ident) => {$i} }
-    fn main() {
-        let b = "test";
-        foo!(b);
-    }"#,
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let a = "test";
+    foo!(a<|>);
+}
+"#,
+            r#"
+macro_rules! foo {($i:ident) => {$i} }
+fn main() {
+    let b = "test";
+    foo!(b);
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_for_macro_define_fn() {
-        test_rename(
-            r#"
-    macro_rules! define_fn {($id:ident) => { fn $id{} }}
-    define_fn!(foo);
-    fn main() {
-        fo<|>o();
-    }"#,
+        check(
             "bar",
             r#"
-    macro_rules! define_fn {($id:ident) => { fn $id{} }}
-    define_fn!(bar);
-    fn main() {
-        bar();
-    }"#,
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(foo);
+fn main() {
+    fo<|>o();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_for_macro_define_fn_rev() {
-        test_rename(
-            r#"
-    macro_rules! define_fn {($id:ident) => { fn $id{} }}
-    define_fn!(fo<|>o);
-    fn main() {
-        foo();
-    }"#,
+        check(
             "bar",
             r#"
-    macro_rules! define_fn {($id:ident) => { fn $id{} }}
-    define_fn!(bar);
-    fn main() {
-        bar();
-    }"#,
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(fo<|>o);
+fn main() {
+    foo();
+}
+"#,
+            r#"
+macro_rules! define_fn {($id:ident) => { fn $id{} }}
+define_fn!(bar);
+fn main() {
+    bar();
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_for_param_inside() {
-        test_rename(
-            r#"
-    fn foo(i : u32) -> u32 {
-        i<|>
-    }"#,
-            "j",
-            r#"
-    fn foo(j : u32) -> u32 {
-        j
-    }"#,
-        );
+        check("j", r#"fn foo(i : u32) -> u32 { i<|> }"#, r#"fn foo(j : u32) -> u32 { j }"#);
     }
 
     #[test]
     fn test_rename_refs_for_fn_param() {
-        test_rename(
-            r#"
-    fn foo(i<|> : u32) -> u32 {
-        i
-    }"#,
-            "new_name",
-            r#"
-    fn foo(new_name : u32) -> u32 {
-        new_name
-    }"#,
-        );
+        check("j", r#"fn foo(i<|> : u32) -> u32 { i }"#, r#"fn foo(j : u32) -> u32 { j }"#);
     }
 
     #[test]
     fn test_rename_for_mut_param() {
-        test_rename(
-            r#"
-    fn foo(mut i<|> : u32) -> u32 {
-        i
-    }"#,
-            "new_name",
-            r#"
-    fn foo(mut new_name : u32) -> u32 {
-        new_name
-    }"#,
-        );
+        check("j", r#"fn foo(mut i<|> : u32) -> u32 { i }"#, r#"fn foo(mut j : u32) -> u32 { j }"#);
     }
 
     #[test]
     fn test_rename_struct_field() {
-        test_rename(
+        check(
+            "j",
             r#"
-    struct Foo {
-        i<|>: i32,
-    }
+struct Foo { i<|>: i32 }
 
-    impl Foo {
-        fn new(i: i32) -> Self {
-            Self { i: i }
-        }
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i: i }
     }
-    "#,
-            "j",
+}
+"#,
             r#"
-    struct Foo {
-        j: i32,
-    }
+struct Foo { j: i32 }
 
-    impl Foo {
-        fn new(i: i32) -> Self {
-            Self { j: i }
-        }
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_struct_field_for_shorthand() {
         mark::check!(test_rename_struct_field_for_shorthand);
-        test_rename(
+        check(
+            "j",
             r#"
-    struct Foo {
-        i<|>: i32,
-    }
+struct Foo { i<|>: i32 }
 
-    impl Foo {
-        fn new(i: i32) -> Self {
-            Self { i }
-        }
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { i }
     }
-    "#,
-            "j",
+}
+"#,
             r#"
-    struct Foo {
-        j: i32,
-    }
+struct Foo { j: i32 }
 
-    impl Foo {
-        fn new(i: i32) -> Self {
-            Self { j: i }
-        }
+impl Foo {
+    fn new(i: i32) -> Self {
+        Self { j: i }
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_local_for_field_shorthand() {
         mark::check!(test_rename_local_for_field_shorthand);
-        test_rename(
+        check(
+            "j",
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn new(i<|>: i32) -> Self {
-            Self { i }
-        }
+impl Foo {
+    fn new(i<|>: i32) -> Self {
+        Self { i }
     }
-    "#,
-            "j",
+}
+"#,
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn new(j: i32) -> Self {
-            Self { i: j }
-        }
+impl Foo {
+    fn new(j: i32) -> Self {
+        Self { i: j }
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_field_shorthand_correct_struct() {
-        test_rename(
-            r#"
-    struct Foo {
-        i<|>: i32,
-    }
-
-    struct Bar {
-        i: i32,
-    }
-
-    impl Bar {
-        fn new(i: i32) -> Self {
-            Self { i }
-        }
-    }
-    "#,
+        check(
             "j",
             r#"
-    struct Foo {
-        j: i32,
-    }
+struct Foo { i<|>: i32 }
+struct Bar { i: i32 }
 
-    struct Bar {
-        i: i32,
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
     }
+}
+"#,
+            r#"
+struct Foo { j: i32 }
+struct Bar { i: i32 }
 
-    impl Bar {
-        fn new(i: i32) -> Self {
-            Self { i }
-        }
+impl Bar {
+    fn new(i: i32) -> Self {
+        Self { i }
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_shadow_local_for_struct_shorthand() {
-        test_rename(
+        check(
+            "j",
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    fn baz(i<|>: i32) -> Self {
-         let x = Foo { i };
-         {
-             let i = 0;
-             Foo { i }
-         }
+fn baz(i<|>: i32) -> Self {
+     let x = Foo { i };
+     {
+         let i = 0;
+         Foo { i }
      }
-    "#,
-            "j",
+}
+"#,
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    fn baz(j: i32) -> Self {
-         let x = Foo { i: j };
-         {
-             let i = 0;
-             Foo { i }
-         }
+fn baz(j: i32) -> Self {
+     let x = Foo { i: j };
+     {
+         let i = 0;
+         Foo { i }
      }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_rename_mod() {
-        let (analysis, position) = analysis_and_position(
-            "
-            //- /lib.rs
-            mod bar;
-
-            //- /bar.rs
-            mod foo<|>;
-
-            //- /bar/foo.rs
-            // emtpy
-            ",
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+
+//- /bar.rs
+mod foo<|>;
+
+//- /bar/foo.rs
+// empty
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 4..7,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    2,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 4..7,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    3,
+                                ),
+                                anchor: FileId(
+                                    3,
+                                ),
+                                dst: "foo2.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
         );
-        let new_name = "foo2";
-        let source_change = analysis.rename(position, new_name).unwrap();
-        assert_debug_snapshot!(&source_change,
-@r###"
-        Some(
-            RangeInfo {
-                range: 4..7,
-                info: SourceChange {
-                    source_file_edits: [
-                        SourceFileEdit {
-                            file_id: FileId(
-                                2,
-                            ),
-                            edit: TextEdit {
-                                indels: [
-                                    Indel {
-                                        insert: "foo2",
-                                        delete: 4..7,
-                                    },
-                                ],
+    }
+
+    #[test]
+    fn test_rename_mod_in_use_tree() {
+        check_expect(
+            "quux",
+            r#"
+//- /main.rs
+pub mod foo;
+pub mod bar;
+fn main() {}
+
+//- /foo.rs
+pub struct FooContent;
+
+//- /bar.rs
+use crate::foo<|>::FooContent;
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 11..14,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "quux",
+                                            delete: 8..11,
+                                        },
+                                    ],
+                                },
                             },
-                        },
-                    ],
-                    file_system_edits: [
-                        MoveFile {
-                            src: FileId(
-                                3,
-                            ),
-                            dst_source_root: SourceRootId(
-                                0,
-                            ),
-                            dst_path: "bar/foo2.rs",
-                        },
-                    ],
-                    is_snippet: false,
-                },
-            },
-        )
-        "###);
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    3,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "quux",
+                                            delete: 11..14,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "quux.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
     }
 
     #[test]
     fn test_rename_mod_in_dir() {
-        let (analysis, position) = analysis_and_position(
-            "
-            //- /lib.rs
-            mod fo<|>o;
-            //- /foo/mod.rs
-            // emtpy
-            ",
-        );
-        let new_name = "foo2";
-        let source_change = analysis.rename(position, new_name).unwrap();
-        assert_debug_snapshot!(&source_change,
-        @r###"
-        Some(
-            RangeInfo {
-                range: 4..7,
-                info: SourceChange {
-                    source_file_edits: [
-                        SourceFileEdit {
-                            file_id: FileId(
-                                1,
-                            ),
-                            edit: TextEdit {
-                                indels: [
-                                    Indel {
-                                        insert: "foo2",
-                                        delete: 4..7,
-                                    },
-                                ],
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod fo<|>o;
+//- /foo/mod.rs
+// emtpy
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 4..7,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 4..7,
+                                        },
+                                    ],
+                                },
                             },
-                        },
-                    ],
-                    file_system_edits: [
-                        MoveFile {
-                            src: FileId(
-                                2,
-                            ),
-                            dst_source_root: SourceRootId(
-                                0,
-                            ),
-                            dst_path: "foo2/mod.rs",
-                        },
-                    ],
-                    is_snippet: false,
-                },
-            },
-        )
-        "###
-               );
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "../foo2/mod.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
     }
 
     #[test]
-    fn test_module_rename_in_path() {
-        test_rename(
+    fn test_rename_unusually_nested_mod() {
+        check_expect(
+            "bar",
             r#"
-    mod <|>foo {
-        pub fn bar() {}
+//- /lib.rs
+mod outer { mod fo<|>o; }
+
+//- /outer/foo.rs
+// emtpy
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 16..19,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "bar",
+                                            delete: 16..19,
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    2,
+                                ),
+                                anchor: FileId(
+                                    2,
+                                ),
+                                dst: "bar.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
     }
 
-    fn main() {
-        foo::bar();
-    }"#,
+    #[test]
+    fn test_module_rename_in_path() {
+        check(
             "baz",
             r#"
-    mod baz {
-        pub fn bar() {}
-    }
+mod <|>foo { pub fn bar() {} }
 
-    fn main() {
-        baz::bar();
-    }"#,
+fn main() { foo::bar(); }
+"#,
+            r#"
+mod baz { pub fn bar() {} }
+
+fn main() { baz::bar(); }
+"#,
         );
     }
 
     #[test]
     fn test_rename_mod_filename_and_path() {
-        let (analysis, position) = analysis_and_position(
-            "
-            //- /lib.rs
-            mod bar;
-            fn f() {
-                bar::foo::fun()
-            }
-
-            //- /bar.rs
-            pub mod foo<|>;
+        check_expect(
+            "foo2",
+            r#"
+//- /lib.rs
+mod bar;
+fn f() {
+    bar::foo::fun()
+}
 
-            //- /bar/foo.rs
-            // pub fn fun() {}
-            ",
-        );
-        let new_name = "foo2";
-        let source_change = analysis.rename(position, new_name).unwrap();
-        assert_debug_snapshot!(&source_change,
-@r###"
-        Some(
-            RangeInfo {
-                range: 8..11,
-                info: SourceChange {
-                    source_file_edits: [
-                        SourceFileEdit {
-                            file_id: FileId(
-                                2,
-                            ),
-                            edit: TextEdit {
-                                indels: [
-                                    Indel {
-                                        insert: "foo2",
-                                        delete: 8..11,
-                                    },
-                                ],
+//- /bar.rs
+pub mod foo<|>;
+
+//- /bar/foo.rs
+// pub fn fun() {}
+"#,
+            expect![[r#"
+                RangeInfo {
+                    range: 8..11,
+                    info: SourceChange {
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    2,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 8..11,
+                                        },
+                                    ],
+                                },
                             },
-                        },
-                        SourceFileEdit {
-                            file_id: FileId(
-                                1,
-                            ),
-                            edit: TextEdit {
-                                indels: [
-                                    Indel {
-                                        insert: "foo2",
-                                        delete: 27..30,
-                                    },
-                                ],
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    indels: [
+                                        Indel {
+                                            insert: "foo2",
+                                            delete: 27..30,
+                                        },
+                                    ],
+                                },
                             },
-                        },
-                    ],
-                    file_system_edits: [
-                        MoveFile {
-                            src: FileId(
-                                3,
-                            ),
-                            dst_source_root: SourceRootId(
-                                0,
-                            ),
-                            dst_path: "bar/foo2.rs",
-                        },
-                    ],
-                    is_snippet: false,
-                },
-            },
-        )
-        "###);
+                        ],
+                        file_system_edits: [
+                            MoveFile {
+                                src: FileId(
+                                    3,
+                                ),
+                                anchor: FileId(
+                                    3,
+                                ),
+                                dst: "foo2.rs",
+                            },
+                        ],
+                        is_snippet: false,
+                    },
+                }
+            "#]],
+        );
     }
 
     #[test]
     fn test_enum_variant_from_module_1() {
-        test_rename(
+        check(
+            "Baz",
             r#"
-    mod foo {
-        pub enum Foo {
-            Bar<|>,
-        }
-    }
+mod foo {
+    pub enum Foo { Bar<|> }
+}
 
-    fn func(f: foo::Foo) {
-        match f {
-            foo::Foo::Bar => {}
-        }
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Bar => {}
     }
-    "#,
-            "Baz",
+}
+"#,
             r#"
-    mod foo {
-        pub enum Foo {
-            Baz,
-        }
-    }
+mod foo {
+    pub enum Foo { Baz }
+}
 
-    fn func(f: foo::Foo) {
-        match f {
-            foo::Foo::Baz => {}
-        }
+fn func(f: foo::Foo) {
+    match f {
+        foo::Foo::Baz => {}
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_enum_variant_from_module_2() {
-        test_rename(
+        check(
+            "baz",
             r#"
-    mod foo {
-        pub struct Foo {
-            pub bar<|>: uint,
-        }
-    }
+mod foo {
+    pub struct Foo { pub bar<|>: uint }
+}
 
-    fn foo(f: foo::Foo) {
-        let _ = f.bar;
-    }
-    "#,
-            "baz",
+fn foo(f: foo::Foo) {
+    let _ = f.bar;
+}
+"#,
             r#"
-    mod foo {
-        pub struct Foo {
-            pub baz: uint,
-        }
-    }
+mod foo {
+    pub struct Foo { pub baz: uint }
+}
 
-    fn foo(f: foo::Foo) {
-        let _ = f.baz;
-    }
-    "#,
+fn foo(f: foo::Foo) {
+    let _ = f.baz;
+}
+"#,
         );
     }
 
     #[test]
     fn test_parameter_to_self() {
-        test_rename(
+        check(
+            "self",
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(foo<|>: &mut Foo) -> i32 {
-            foo.i
-        }
+impl Foo {
+    fn f(foo<|>: &mut Foo) -> i32 {
+        foo.i
     }
-    "#,
-            "self",
+}
+"#,
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(&mut self) -> i32 {
-            self.i
-        }
+impl Foo {
+    fn f(&mut self) -> i32 {
+        self.i
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_self_to_parameter() {
-        test_rename(
+        check(
+            "foo",
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(&mut <|>self) -> i32 {
-            self.i
-        }
+impl Foo {
+    fn f(&mut <|>self) -> i32 {
+        self.i
     }
-    "#,
-            "foo",
+}
+"#,
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(foo: &mut Foo) -> i32 {
-            foo.i
-        }
+impl Foo {
+    fn f(foo: &mut Foo) -> i32 {
+        foo.i
     }
-    "#,
+}
+"#,
         );
     }
 
     #[test]
     fn test_self_in_path_to_parameter() {
-        test_rename(
+        check(
+            "foo",
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(&self) -> i32 {
-            let self_var = 1;
-            self<|>.i
-        }
+impl Foo {
+    fn f(&self) -> i32 {
+        let self_var = 1;
+        self<|>.i
     }
-    "#,
-            "foo",
+}
+"#,
             r#"
-    struct Foo {
-        i: i32,
-    }
+struct Foo { i: i32 }
 
-    impl Foo {
-        fn f(foo: &Foo) -> i32 {
-            let self_var = 1;
-            foo.i
-        }
+impl Foo {
+    fn f(foo: &Foo) -> i32 {
+        let self_var = 1;
+        foo.i
     }
-    "#,
+}
+"#,
         );
     }
-
-    fn test_rename(text: &str, new_name: &str, expected: &str) {
-        let (analysis, position) = single_file_with_position(text);
-        let source_change = analysis.rename(position, new_name).unwrap();
-        let mut text_edit_builder = TextEditBuilder::default();
-        let mut file_id: Option<FileId> = None;
-        if let Some(change) = source_change {
-            for edit in change.info.source_file_edits {
-                file_id = Some(edit.file_id);
-                for indel in edit.edit.into_iter() {
-                    text_edit_builder.replace(indel.delete, indel.insert);
-                }
-            }
-        }
-        let mut result = analysis.file_text(file_id.unwrap()).unwrap().to_string();
-        text_edit_builder.finish().apply(&mut result);
-        assert_eq_text!(expected, &*result);
-    }
 }
diff --git a/crates/ra_ide/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index 286d45eee..ed15d6494 100644
--- a/crates/ra_ide/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
@@ -1,31 +1,31 @@
+use std::fmt;
+
 use hir::{AsAssocItem, Attrs, HirFileId, InFile, Semantics};
 use itertools::Itertools;
+use ra_cfg::CfgExpr;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
-    ast::{self, AstNode, AttrsOwner, ModuleItemOwner, NameOwner},
-    match_ast, SyntaxNode, TextRange,
+    ast::{self, AstNode, AttrsOwner, DocCommentsOwner, ModuleItemOwner, NameOwner},
+    match_ast, SyntaxNode,
 };
 
-use crate::FileId;
-use ast::DocCommentsOwner;
-use ra_cfg::CfgExpr;
-use std::fmt::Display;
+use crate::{display::ToNav, FileId, NavigationTarget};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Runnable {
-    pub range: TextRange,
+    pub nav: NavigationTarget,
     pub kind: RunnableKind,
     pub cfg_exprs: Vec<CfgExpr>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum TestId {
     Name(String),
     Path(String),
 }
 
-impl Display for TestId {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+impl fmt::Display for TestId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             TestId::Name(name) => write!(f, "{}", name),
             TestId::Path(path) => write!(f, "{}", path),
@@ -33,7 +33,7 @@ impl Display for TestId {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum RunnableKind {
     Test { test_id: TestId, attr: TestAttr },
     TestMod { path: String },
@@ -42,6 +42,42 @@ pub enum RunnableKind {
     Bin,
 }
 
+#[derive(Debug, Eq, PartialEq)]
+pub struct RunnableAction {
+    pub run_title: &'static str,
+    pub debugee: bool,
+}
+
+const TEST: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Test", debugee: true };
+const DOCTEST: RunnableAction =
+    RunnableAction { run_title: "▶\u{fe0e} Run Doctest", debugee: false };
+const BENCH: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Bench", debugee: true };
+const BIN: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run", debugee: true };
+
+impl Runnable {
+    // test package::module::testname
+    pub fn label(&self, target: Option<String>) -> String {
+        match &self.kind {
+            RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
+            RunnableKind::TestMod { path } => format!("test-mod {}", path),
+            RunnableKind::Bench { test_id } => format!("bench {}", test_id),
+            RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
+            RunnableKind::Bin => {
+                target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
+            }
+        }
+    }
+
+    pub fn action(&self) -> &'static RunnableAction {
+        match &self.kind {
+            RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => &TEST,
+            RunnableKind::DocTest { .. } => &DOCTEST,
+            RunnableKind::Bench { .. } => &BENCH,
+            RunnableKind::Bin => &BIN,
+        }
+    }
+}
+
 // Feature: Run
 //
 // Shows a popup suggesting to run a test/benchmark/binary **at the current cursor
@@ -59,7 +95,11 @@ pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
     source_file.syntax().descendants().filter_map(|i| runnable(&sema, i, file_id)).collect()
 }
 
-fn runnable(sema: &Semantics<RootDatabase>, item: SyntaxNode, file_id: FileId) -> Option<Runnable> {
+pub(crate) fn runnable(
+    sema: &Semantics<RootDatabase>,
+    item: SyntaxNode,
+    file_id: FileId,
+) -> Option<Runnable> {
     match_ast! {
         match item {
             ast::FnDef(it) => runnable_fn(sema, it, file_id),
@@ -131,10 +171,19 @@ fn runnable_fn(
     let cfg_exprs =
         attrs.by_key("cfg").tt_values().map(|subtree| ra_cfg::parse_cfg(subtree)).collect();
 
-    Some(Runnable { range: fn_def.syntax().text_range(), kind, cfg_exprs })
+    let nav = if let RunnableKind::DocTest { .. } = kind {
+        NavigationTarget::from_doc_commented(
+            sema.db,
+            InFile::new(file_id.into(), &fn_def),
+            InFile::new(file_id.into(), &fn_def),
+        )
+    } else {
+        NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def))
+    };
+    Some(Runnable { nav, kind, cfg_exprs })
 }
 
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub struct TestAttr {
     pub ignore: bool,
 }
@@ -183,7 +232,6 @@ fn runnable_mod(
     if !has_test_function {
         return None;
     }
-    let range = module.syntax().text_range();
     let module_def = sema.to_def(&module)?;
 
     let path = module_def
@@ -197,366 +245,586 @@ fn runnable_mod(
     let cfg_exprs =
         attrs.by_key("cfg").tt_values().map(|subtree| ra_cfg::parse_cfg(subtree)).collect();
 
-    Some(Runnable { range, kind: RunnableKind::TestMod { path }, cfg_exprs })
+    let nav = module_def.to_nav(sema.db);
+    Some(Runnable { nav, kind: RunnableKind::TestMod { path }, cfg_exprs })
 }
 
 #[cfg(test)]
 mod tests {
-    use insta::assert_debug_snapshot;
+    use expect::{expect, Expect};
 
     use crate::mock_analysis::analysis_and_position;
 
+    use super::{RunnableAction, BENCH, BIN, DOCTEST, TEST};
+
+    fn check(
+        ra_fixture: &str,
+        // FIXME: fold this into `expect` as well
+        actions: &[&RunnableAction],
+        expect: Expect,
+    ) {
+        let (analysis, position) = analysis_and_position(ra_fixture);
+        let runnables = analysis.runnables(position.file_id).unwrap();
+        expect.assert_debug_eq(&runnables);
+        assert_eq!(
+            actions,
+            runnables.into_iter().map(|it| it.action()).collect::<Vec<_>>().as_slice()
+        );
+    }
+
     #[test]
     fn test_runnables() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        fn main() {}
-
-        #[test]
-        fn test_foo() {}
-
-        #[test]
-        #[ignore]
-        fn test_foo() {}
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..21,
-                kind: Bin,
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 22..46,
-                kind: Test {
-                    test_id: Path(
-                        "test_foo",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
+//- /lib.rs
+<|>
+fn main() {}
+
+#[test]
+fn test_foo() {}
+
+#[test]
+#[ignore]
+fn test_foo() {}
+
+#[bench]
+fn bench() {}
+"#,
+            &[&BIN, &TEST, &TEST, &BENCH],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            name: "main",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 15..39,
+                            name: "test_foo",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                26..34,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 41..75,
+                            name: "test_foo",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                62..70,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo",
+                            ),
+                            attr: TestAttr {
+                                ignore: true,
+                            },
+                        },
+                        cfg_exprs: [],
                     },
-                },
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 47..81,
-                kind: Test {
-                    test_id: Path(
-                        "test_foo",
-                    ),
-                    attr: TestAttr {
-                        ignore: true,
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 77..99,
+                            name: "bench",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                89..94,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bench {
+                            test_id: Path(
+                                "bench",
+                            ),
+                        },
+                        cfg_exprs: [],
                     },
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_doc_test() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        fn main() {}
-
-        /// ```
-        /// let x = 5;
-        /// ```
-        fn foo() {}
-        "#,
+//- /lib.rs
+<|>
+fn main() {}
+
+/// ```
+/// let x = 5;
+/// ```
+fn foo() {}
+"#,
+            &[&BIN, &DOCTEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            name: "main",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 15..57,
+                            name: "foo",
+                            kind: FN_DEF,
+                            focus_range: None,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: DocTest {
+                            test_id: Path(
+                                "foo",
+                            ),
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
         );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..21,
-                kind: Bin,
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 22..64,
-                kind: DocTest {
-                    test_id: Path(
-                        "foo",
-                    ),
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
     }
 
     #[test]
     fn test_runnables_doc_test_in_impl() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        fn main() {}
-
-        struct Data;
-        impl Data {
-            /// ```
-            /// let x = 5;
-            /// ```
-            fn foo() {}
-        }
-        "#,
+//- /lib.rs
+<|>
+fn main() {}
+
+struct Data;
+impl Data {
+    /// ```
+    /// let x = 5;
+    /// ```
+    fn foo() {}
+}
+"#,
+            &[&BIN, &DOCTEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..13,
+                            name: "main",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                4..8,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Bin,
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 44..98,
+                            name: "foo",
+                            kind: FN_DEF,
+                            focus_range: None,
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: DocTest {
+                            test_id: Path(
+                                "Data::foo",
+                            ),
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
         );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..21,
-                kind: Bin,
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 51..105,
-                kind: DocTest {
-                    test_id: Path(
-                        "Data::foo",
-                    ),
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
     }
 
     #[test]
     fn test_runnables_module() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        mod test_mod {
-            #[test]
-            fn test_foo1() {}
-        }
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..59,
-                kind: TestMod {
-                    path: "test_mod",
-                },
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 28..57,
-                kind: Test {
-                    test_id: Path(
-                        "test_mod::test_foo1",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
+//- /lib.rs
+<|>
+mod test_mod {
+    #[test]
+    fn test_foo1() {}
+}
+"#,
+            &[&TEST, &TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..51,
+                            name: "test_mod",
+                            kind: MODULE,
+                            focus_range: Some(
+                                5..13,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "test_mod",
+                        },
+                        cfg_exprs: [],
                     },
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 20..49,
+                            name: "test_foo1",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                35..44,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_mod::test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_one_depth_layer_module() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        mod foo {
-            mod test_mod {
-                #[test]
-                fn test_foo1() {}
-            }
-        }
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 23..85,
-                kind: TestMod {
-                    path: "foo::test_mod",
-                },
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 46..79,
-                kind: Test {
-                    test_id: Path(
-                        "foo::test_mod::test_foo1",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
+//- /lib.rs
+<|>
+mod foo {
+    mod test_mod {
+        #[test]
+        fn test_foo1() {}
+    }
+}
+"#,
+            &[&TEST, &TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 15..77,
+                            name: "test_mod",
+                            kind: MODULE,
+                            focus_range: Some(
+                                19..27,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "foo::test_mod",
+                        },
+                        cfg_exprs: [],
+                    },
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 38..71,
+                            name: "test_foo1",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                57..66,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "foo::test_mod::test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
                     },
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_multiple_depth_module() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        mod foo {
-            mod bar {
-                mod test_mod {
-                    #[test]
-                    fn test_foo1() {}
-                }
-            }
+//- /lib.rs
+<|>
+mod foo {
+    mod bar {
+        mod test_mod {
+            #[test]
+            fn test_foo1() {}
         }
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 41..115,
-                kind: TestMod {
-                    path: "foo::bar::test_mod",
-                },
-                cfg_exprs: [],
-            },
-            Runnable {
-                range: 68..105,
-                kind: Test {
-                    test_id: Path(
-                        "foo::bar::test_mod::test_foo1",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
+    }
+}
+"#,
+            &[&TEST, &TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 33..107,
+                            name: "test_mod",
+                            kind: MODULE,
+                            focus_range: Some(
+                                37..45,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "foo::bar::test_mod",
+                        },
+                        cfg_exprs: [],
                     },
-                },
-                cfg_exprs: [],
-            },
-        ]
-        "###
-                );
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 60..97,
+                            name: "test_foo1",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                83..92,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "foo::bar::test_mod::test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_with_feature() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs crate:foo cfg:feature=foo
-        <|> //empty
-        #[test]
-        #[cfg(feature = "foo")]
-        fn test_foo1() {}
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..58,
-                kind: Test {
-                    test_id: Path(
-                        "test_foo1",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
-                    },
-                },
-                cfg_exprs: [
-                    KeyValue {
-                        key: "feature",
-                        value: "foo",
+//- /lib.rs crate:foo cfg:feature=foo
+<|>
+#[test]
+#[cfg(feature = "foo")]
+fn test_foo1() {}
+"#,
+            &[&TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..50,
+                            name: "test_foo1",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                36..45,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [
+                            KeyValue {
+                                key: "feature",
+                                value: "foo",
+                            },
+                        ],
                     },
-                ],
-            },
-        ]
-        "###
-                );
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_with_features() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs crate:foo cfg:feature=foo,feature=bar
-        <|> //empty
-        #[test]
-        #[cfg(all(feature = "foo", feature = "bar"))]
-        fn test_foo1() {}
-        "#,
-        );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert_debug_snapshot!(&runnables,
-        @r###"
-        [
-            Runnable {
-                range: 1..80,
-                kind: Test {
-                    test_id: Path(
-                        "test_foo1",
-                    ),
-                    attr: TestAttr {
-                        ignore: false,
-                    },
-                },
-                cfg_exprs: [
-                    All(
-                        [
-                            KeyValue {
-                                key: "feature",
-                                value: "foo",
-                            },
-                            KeyValue {
-                                key: "feature",
-                                value: "bar",
+//- /lib.rs crate:foo cfg:feature=foo,feature=bar
+<|>
+#[test]
+#[cfg(all(feature = "foo", feature = "bar"))]
+fn test_foo1() {}
+"#,
+            &[&TEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 1..72,
+                            name: "test_foo1",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                58..67,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "test_foo1",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
                             },
+                        },
+                        cfg_exprs: [
+                            All(
+                                [
+                                    KeyValue {
+                                        key: "feature",
+                                        value: "foo",
+                                    },
+                                    KeyValue {
+                                        key: "feature",
+                                        value: "bar",
+                                    },
+                                ],
+                            ),
                         ],
-                    ),
-                ],
-            },
-        ]
-        "###
-                );
+                    },
+                ]
+            "#]],
+        );
     }
 
     #[test]
     fn test_runnables_no_test_function_in_module() {
-        let (analysis, pos) = analysis_and_position(
+        check(
             r#"
-        //- /lib.rs
-        <|> //empty
-        mod test_mod {
-            fn foo1() {}
-        }
-        "#,
+//- /lib.rs
+<|>
+mod test_mod {
+    fn foo1() {}
+}
+"#,
+            &[],
+            expect![[r#"
+                []
+            "#]],
         );
-        let runnables = analysis.runnables(pos.file_id).unwrap();
-        assert!(runnables.is_empty())
     }
 }
diff --git a/crates/ra_ide/src/snapshots/highlight_injection.html b/crates/ra_ide/src/snapshots/highlight_injection.html
deleted file mode 100644
index 68fc589bc..000000000
--- a/crates/ra_ide/src/snapshots/highlight_injection.html
+++ /dev/null
@@ -1,41 +0,0 @@
-
-<style>
-body                { margin: 0; }
-pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
-
-.lifetime           { color: #DFAF8F; font-style: italic; }
-.comment            { color: #7F9F7F; }
-.struct, .enum      { color: #7CB8BB; }
-.enum_variant       { color: #BDE0F3; }
-.string_literal     { color: #CC9393; }
-.field              { color: #94BFF3; }
-.function           { color: #93E0E3; }
-.parameter          { color: #94BFF3; }
-.text               { color: #DCDCCC; }
-.type               { color: #7CB8BB; }
-.builtin_type       { color: #8CD0D3; }
-.type_param         { color: #DFAF8F; }
-.attribute          { color: #94BFF3; }
-.numeric_literal    { color: #BFEBBF; }
-.bool_literal       { color: #BFE6EB; }
-.macro              { color: #94BFF3; }
-.module             { color: #AFD8AF; }
-.variable           { color: #DCDCCC; }
-.format_specifier   { color: #CC696B; }
-.mutable            { text-decoration: underline; }
-
-.keyword            { color: #F0DFAF; font-weight: bold; }
-.keyword.unsafe     { color: #BC8383; font-weight: bold; }
-.control            { font-style: italic; }
-</style>
-<pre><code><span class="keyword">fn</span> <span class="function declaration">fixture</span>(<span class="variable declaration">ra_fixture</span>: &<span class="builtin_type">str</span>) {}
-
-<span class="keyword">fn</span> <span class="function declaration">main</span>() {
-    <span class="function">fixture</span>(<span class="string_literal">r#"</span>
-        <span class="keyword">trait</span> <span class="trait declaration">Foo</span> {
-            <span class="keyword">fn</span> <span class="function declaration">foo</span>() {
-                <span class="macro">println!</span>(<span class="string_literal">"2 + 2 = {}"</span>, <span class="numeric_literal">4</span>);
-            }
-        }<span class="string_literal">"#</span>
-    );
-}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/highlight_strings.html b/crates/ra_ide/src/snapshots/highlight_strings.html
deleted file mode 100644
index 326744361..000000000
--- a/crates/ra_ide/src/snapshots/highlight_strings.html
+++ /dev/null
@@ -1,84 +0,0 @@
-
-<style>
-body                { margin: 0; }
-pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
-
-.lifetime           { color: #DFAF8F; font-style: italic; }
-.comment            { color: #7F9F7F; }
-.struct, .enum      { color: #7CB8BB; }
-.enum_variant       { color: #BDE0F3; }
-.string_literal     { color: #CC9393; }
-.field              { color: #94BFF3; }
-.function           { color: #93E0E3; }
-.parameter          { color: #94BFF3; }
-.text               { color: #DCDCCC; }
-.type               { color: #7CB8BB; }
-.builtin_type       { color: #8CD0D3; }
-.type_param         { color: #DFAF8F; }
-.attribute          { color: #94BFF3; }
-.numeric_literal    { color: #BFEBBF; }
-.bool_literal       { color: #BFE6EB; }
-.macro              { color: #94BFF3; }
-.module             { color: #AFD8AF; }
-.variable           { color: #DCDCCC; }
-.format_specifier   { color: #CC696B; }
-.mutable            { text-decoration: underline; }
-
-.keyword            { color: #F0DFAF; font-weight: bold; }
-.keyword.unsafe     { color: #BC8383; font-weight: bold; }
-.control            { font-style: italic; }
-</style>
-<pre><code><span class="macro">macro_rules!</span> <span class="macro declaration">println</span> {
-    ($($arg:tt)*) =&gt; ({
-        $<span class="keyword">crate</span>::io::_print($<span class="keyword">crate</span>::format_args_nl!($($arg)*));
-    })
-}
-#[rustc_builtin_macro]
-<span class="macro">macro_rules!</span> <span class="macro declaration">format_args_nl</span> {
-    ($fmt:expr) =&gt; {{ <span class="comment">/* compiler built-in */</span> }};
-    ($fmt:expr, $($args:tt)*) =&gt; {{ <span class="comment">/* compiler built-in */</span> }};
-}
-
-<span class="keyword">fn</span> <span class="function declaration">main</span>() {
-    <span class="comment">// from https://doc.rust-lang.org/std/fmt/index.html</span>
-    <span class="macro">println!</span>(<span class="string_literal">"Hello"</span>);                 <span class="comment">// =&gt; "Hello"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"Hello, </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"world"</span>);   <span class="comment">// =&gt; "Hello, world!"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"The number is </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">1</span>);   <span class="comment">// =&gt; "The number is 1"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">?</span><span class="format_specifier">}</span><span class="string_literal">"</span>, (<span class="numeric_literal">3</span>, <span class="numeric_literal">4</span>));          <span class="comment">// =&gt; "(3, 4)"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">value</span><span class="format_specifier">}</span><span class="string_literal">"</span>, value=<span class="numeric_literal">4</span>);      <span class="comment">// =&gt; "4"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">1</span>, <span class="numeric_literal">2</span>);           <span class="comment">// =&gt; "1 2"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">4</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">42</span>);             <span class="comment">// =&gt; "0042" with leading zerosV</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">1</span>, <span class="numeric_literal">2</span>);   <span class="comment">// =&gt; "2 1 1 2"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">argument</span><span class="format_specifier">}</span><span class="string_literal">"</span>, argument = <span class="string_literal">"test"</span>);   <span class="comment">// =&gt; "test"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">1</span>, name = <span class="numeric_literal">2</span>);          <span class="comment">// =&gt; "2 1"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">a</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">c</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">b</span><span class="format_specifier">}</span><span class="string_literal">"</span>, a=<span class="string_literal">"a"</span>, b=<span class="char_literal">'b'</span>, c=<span class="numeric_literal">3</span>);  <span class="comment">// =&gt; "a 3 b"</span>
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">1</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>, <span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="variable">width</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>, width = <span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">&lt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">-</span><span class="format_specifier">&lt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">^</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">&gt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">+</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="variable">x</span><span class="string_literal">}!"</span>, <span class="numeric_literal">27</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, -<span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="numeric_literal">0</span><span class="numeric_literal">10</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">27</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="string_literal">"x"</span>, <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">5</span>, <span class="string_literal">"x"</span>, <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">1</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="string_literal">"x"</span>, <span class="numeric_literal">5</span>, <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">"</span>,    <span class="string_literal">"x"</span>, <span class="numeric_literal">5</span>, <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">"</span>,   <span class="string_literal">"x"</span>, <span class="numeric_literal">5</span>, <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="variable">number</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="variable">prec</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="string_literal">"x"</span>, prec = <span class="numeric_literal">5</span>, number = <span class="numeric_literal">0.01</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 fractional digits"</span>, <span class="string_literal">"Hello"</span>, <span class="numeric_literal">3</span>, name=<span class="numeric_literal">1234.56</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 characters"</span>, <span class="string_literal">"Hello"</span>, <span class="numeric_literal">3</span>, name=<span class="string_literal">"1234.56"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">&gt;</span><span class="numeric_literal">8</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 right-aligned characters"</span>, <span class="string_literal">"Hello"</span>, <span class="numeric_literal">3</span>, name=<span class="string_literal">"1234.56"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"Hello {{}}"</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"{{ Hello"</span>);
-
-    <span class="macro">println!</span>(<span class="string_literal">r"Hello, </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"world"</span>);
-
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">\x41</span><span class="format_specifier">}</span><span class="string_literal">"</span>, A = <span class="numeric_literal">92</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">ничоси</span><span class="format_specifier">}</span><span class="string_literal">"</span>, ничоси = <span class="numeric_literal">92</span>);
-}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
deleted file mode 100644
index 352e35095..000000000
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ /dev/null
@@ -1,101 +0,0 @@
-
-<style>
-body                { margin: 0; }
-pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
-
-.lifetime           { color: #DFAF8F; font-style: italic; }
-.comment            { color: #7F9F7F; }
-.struct, .enum      { color: #7CB8BB; }
-.enum_variant       { color: #BDE0F3; }
-.string_literal     { color: #CC9393; }
-.field              { color: #94BFF3; }
-.function           { color: #93E0E3; }
-.parameter          { color: #94BFF3; }
-.text               { color: #DCDCCC; }
-.type               { color: #7CB8BB; }
-.builtin_type       { color: #8CD0D3; }
-.type_param         { color: #DFAF8F; }
-.attribute          { color: #94BFF3; }
-.numeric_literal    { color: #BFEBBF; }
-.bool_literal       { color: #BFE6EB; }
-.macro              { color: #94BFF3; }
-.module             { color: #AFD8AF; }
-.variable           { color: #DCDCCC; }
-.format_specifier   { color: #CC696B; }
-.mutable            { text-decoration: underline; }
-
-.keyword            { color: #F0DFAF; font-weight: bold; }
-.keyword.unsafe     { color: #BC8383; font-weight: bold; }
-.control            { font-style: italic; }
-</style>
-<pre><code><span class="attribute">#[</span><span class="function attribute">derive</span><span class="attribute">(Clone, Debug)]</span>
-<span class="keyword">struct</span> <span class="struct declaration">Foo</span> {
-    <span class="keyword">pub</span> <span class="field declaration">x</span>: <span class="builtin_type">i32</span>,
-    <span class="keyword">pub</span> <span class="field declaration">y</span>: <span class="builtin_type">i32</span>,
-}
-
-<span class="keyword">trait</span> <span class="trait declaration">Bar</span> {
-    <span class="keyword">fn</span> <span class="function declaration">bar</span>(&<span class="self_keyword">self</span>) -&gt; <span class="builtin_type">i32</span>;
-}
-
-<span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> {
-    <span class="keyword">fn</span> <span class="function declaration">bar</span>(&<span class="self_keyword">self</span>) -&gt; <span class="builtin_type">i32</span> {
-        <span class="self_keyword">self</span>.<span class="field">x</span>
-    }
-}
-
-<span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable">STATIC_MUT</span>: <span class="builtin_type">i32</span> = <span class="numeric_literal">0</span>;
-
-<span class="keyword">fn</span> <span class="function declaration">foo</span>&lt;<span class="lifetime declaration">'a</span>, <span class="type_param declaration">T</span>&gt;() -&gt; <span class="type_param">T</span> {
-    <span class="function">foo</span>::&lt;<span class="lifetime">'a</span>, <span class="builtin_type">i32</span>&gt;()
-}
-
-<span class="macro">macro_rules!</span> <span class="macro declaration">def_fn</span> {
-    ($($tt:tt)*) =&gt; {$($tt)*}
-}
-
-<span class="macro">def_fn!</span> {
-    <span class="keyword">fn</span> <span class="function declaration">bar</span>() -&gt; <span class="builtin_type">u32</span> {
-        <span class="numeric_literal">100</span>
-    }
-}
-
-<span class="comment">// comment</span>
-<span class="keyword">fn</span> <span class="function declaration">main</span>() {
-    <span class="macro">println!</span>(<span class="string_literal">"Hello, {}!"</span>, <span class="numeric_literal">92</span>);
-
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">vec</span> = <span class="unresolved_reference">Vec</span>::<span class="unresolved_reference">new</span>();
-    <span class="keyword control">if</span> <span class="bool_literal">true</span> {
-        <span class="keyword">let</span> <span class="variable declaration">x</span> = <span class="numeric_literal">92</span>;
-        <span class="variable mutable">vec</span>.<span class="unresolved_reference">push</span>(<span class="struct">Foo</span> { <span class="field">x</span>, <span class="field">y</span>: <span class="numeric_literal">1</span> });
-    }
-    <span class="keyword unsafe">unsafe</span> {
-        <span class="variable mutable">vec</span>.<span class="unresolved_reference">set_len</span>(<span class="numeric_literal">0</span>);
-        <span class="static mutable">STATIC_MUT</span> = <span class="numeric_literal">1</span>;
-    }
-
-    <span class="keyword control">for</span> <span class="variable declaration">e</span> <span class="keyword control">in</span> <span class="variable mutable">vec</span> {
-        <span class="comment">// Do nothing</span>
-    }
-
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> = <span class="numeric_literal">42</span>;
-    <span class="keyword">let</span> <span class="variable declaration mutable">y</span> = &<span class="keyword">mut</span> <span class="variable mutable">x</span>;
-    <span class="keyword">let</span> <span class="variable declaration">z</span> = &<span class="variable mutable">y</span>;
-
-    <span class="variable mutable">y</span>;
-}
-
-<span class="keyword">enum</span> <span class="enum declaration">Option</span>&lt;<span class="type_param declaration">T</span>&gt; {
-    <span class="enum_variant declaration">Some</span>(<span class="type_param">T</span>),
-    <span class="enum_variant declaration">None</span>,
-}
-<span class="keyword">use</span> <span class="enum">Option</span>::*;
-
-<span class="keyword">impl</span>&lt;<span class="type_param declaration">T</span>&gt; <span class="enum">Option</span>&lt;<span class="type_param">T</span>&gt; {
-    <span class="keyword">fn</span> <span class="function declaration">and</span>&lt;<span class="type_param declaration">U</span>&gt;(<span class="self_keyword">self</span>, <span class="variable declaration">other</span>: <span class="enum">Option</span>&lt;<span class="type_param">U</span>&gt;) -&gt; <span class="enum">Option</span>&lt;(<span class="type_param">T</span>, <span class="type_param">U</span>)&gt; {
-        <span class="keyword control">match</span> <span class="variable">other</span> {
-            <span class="enum_variant">None</span> =&gt; <span class="macro">unimplemented!</span>(),
-            <span class="variable declaration">Nope</span> =&gt; <span class="variable">Nope</span>,
-        }
-    }
-}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
deleted file mode 100644
index 2a0294f71..000000000
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ /dev/null
@@ -1,42 +0,0 @@
-
-<style>
-body                { margin: 0; }
-pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
-
-.lifetime           { color: #DFAF8F; font-style: italic; }
-.comment            { color: #7F9F7F; }
-.struct, .enum      { color: #7CB8BB; }
-.enum_variant       { color: #BDE0F3; }
-.string_literal     { color: #CC9393; }
-.field              { color: #94BFF3; }
-.function           { color: #93E0E3; }
-.parameter          { color: #94BFF3; }
-.text               { color: #DCDCCC; }
-.type               { color: #7CB8BB; }
-.builtin_type       { color: #8CD0D3; }
-.type_param         { color: #DFAF8F; }
-.attribute          { color: #94BFF3; }
-.numeric_literal    { color: #BFEBBF; }
-.bool_literal       { color: #BFE6EB; }
-.macro              { color: #94BFF3; }
-.module             { color: #AFD8AF; }
-.variable           { color: #DCDCCC; }
-.format_specifier   { color: #CC696B; }
-.mutable            { text-decoration: underline; }
-
-.keyword            { color: #F0DFAF; font-weight: bold; }
-.keyword.unsafe     { color: #BC8383; font-weight: bold; }
-.control            { font-style: italic; }
-</style>
-<pre><code><span class="keyword">fn</span> <span class="function declaration">main</span>() {
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span> = <span class="string_literal">"hello"</span>;
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="2705725358298919760" style="color: hsl(17,51%,74%);">x</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.<span class="unresolved_reference">to_string</span>();
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="3365759661443752373" style="color: hsl(127,76%,66%);">y</span> = <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span>.<span class="unresolved_reference">to_string</span>();
-
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span> = <span class="string_literal">"other color please!"</span>;
-    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="6717528807933952652" style="color: hsl(85,49%,84%);">y</span> = <span class="variable" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span>.<span class="unresolved_reference">to_string</span>();
-}
-
-<span class="keyword">fn</span> <span class="function declaration">bar</span>() {
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span> = <span class="string_literal">"hello"</span>;
-}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/ssr.rs b/crates/ra_ide/src/ssr.rs
index 93e9aee1d..b3e9e5dfe 100644
--- a/crates/ra_ide/src/ssr.rs
+++ b/crates/ra_ide/src/ssr.rs
@@ -1,37 +1,31 @@
-use std::{collections::HashMap, iter::once, str::FromStr};
-
-use ra_db::{SourceDatabase, SourceDatabaseExt};
+use ra_db::SourceDatabaseExt;
 use ra_ide_db::{symbol_index::SymbolsDatabase, RootDatabase};
-use ra_syntax::ast::{
-    make::try_expr_from_text, ArgList, AstToken, CallExpr, Comment, Expr, MethodCallExpr,
-    RecordField, RecordLit,
-};
-use ra_syntax::{AstNode, SyntaxElement, SyntaxKind, SyntaxNode};
-use ra_text_edit::{TextEdit, TextEditBuilder};
-use rustc_hash::FxHashMap;
 
 use crate::SourceFileEdit;
+use ra_ssr::{MatchFinder, SsrError, SsrRule};
 
-#[derive(Debug, PartialEq)]
-pub struct SsrError(String);
-
-impl std::fmt::Display for SsrError {
-    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
-        write!(f, "Parse error: {}", self.0)
-    }
-}
-
-impl std::error::Error for SsrError {}
-
-// Feature: Structural Seach and Replace
+// Feature: Structural Search and Replace
 //
-// Search and replace with named wildcards that will match any expression.
+// Search and replace with named wildcards that will match any expression, type, path, pattern or item.
 // The syntax for a structural search replace command is `<search_pattern> ==>> <replace_pattern>`.
-// A `$<name>:expr` placeholder in the search pattern will match any expression and `$<name>` will reference it in the replacement.
+// A `$<name>` placeholder in the search pattern will match any AST node and `$<name>` will reference it in the replacement.
+// Within a macro call, a placeholder will match up until whatever token follows the placeholder.
+//
+// Placeholders may be given constraints by writing them as `${<name>:<constraint1>:<constraint2>...}`.
+//
+// Supported constraints:
+//
+// |===
+// | Constraint    | Restricts placeholder
+//
+// | kind(literal) | Is a literal (e.g. `42` or `"forty two"`)
+// | not(a)        | Negates the constraint `a`
+// |===
+//
 // Available via the command `rust-analyzer.ssr`.
 //
 // ```rust
-// // Using structural search replace command [foo($a:expr, $b:expr) ==>> ($a).foo($b)]
+// // Using structural search replace command [foo($a, $b) ==>> ($a).foo($b)]
 //
 // // BEFORE
 // String::from(foo(y + 5, z))
@@ -46,584 +40,24 @@ impl std::error::Error for SsrError {}
 // | VS Code | **Rust Analyzer: Structural Search Replace**
 // |===
 pub fn parse_search_replace(
-    query: &str,
+    rule: &str,
     parse_only: bool,
     db: &RootDatabase,
 ) -> Result<Vec<SourceFileEdit>, SsrError> {
     let mut edits = vec![];
-    let query: SsrQuery = query.parse()?;
+    let rule: SsrRule = rule.parse()?;
     if parse_only {
         return Ok(edits);
     }
+    let mut match_finder = MatchFinder::new(db);
+    match_finder.add_rule(rule);
     for &root in db.local_roots().iter() {
         let sr = db.source_root(root);
-        for file_id in sr.walk() {
-            let matches = find(&query.pattern, db.parse(file_id).tree().syntax());
-            if !matches.matches.is_empty() {
-                edits.push(SourceFileEdit { file_id, edit: replace(&matches, &query.template) });
+        for file_id in sr.iter() {
+            if let Some(edit) = match_finder.edits_for_file(file_id) {
+                edits.push(SourceFileEdit { file_id, edit });
             }
         }
     }
     Ok(edits)
 }
-
-#[derive(Debug)]
-struct SsrQuery {
-    pattern: SsrPattern,
-    template: SsrTemplate,
-}
-
-#[derive(Debug)]
-struct SsrPattern {
-    pattern: SyntaxNode,
-    vars: Vec<Var>,
-}
-
-/// represents an `$var` in an SSR query
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-struct Var(String);
-
-#[derive(Debug)]
-struct SsrTemplate {
-    template: SyntaxNode,
-    placeholders: FxHashMap<SyntaxNode, Var>,
-}
-
-type Binding = HashMap<Var, SyntaxNode>;
-
-#[derive(Debug)]
-struct Match {
-    place: SyntaxNode,
-    binding: Binding,
-    ignored_comments: Vec<Comment>,
-}
-
-#[derive(Debug)]
-struct SsrMatches {
-    matches: Vec<Match>,
-}
-
-impl FromStr for SsrQuery {
-    type Err = SsrError;
-
-    fn from_str(query: &str) -> Result<SsrQuery, SsrError> {
-        let mut it = query.split("==>>");
-        let pattern = it.next().expect("at least empty string").trim();
-        let mut template = it
-            .next()
-            .ok_or_else(|| SsrError("Cannot find delemiter `==>>`".into()))?
-            .trim()
-            .to_string();
-        if it.next().is_some() {
-            return Err(SsrError("More than one delimiter found".into()));
-        }
-        let mut vars = vec![];
-        let mut it = pattern.split('$');
-        let mut pattern = it.next().expect("something").to_string();
-
-        for part in it.map(split_by_var) {
-            let (var, var_type, remainder) = part?;
-            is_expr(var_type)?;
-            let new_var = create_name(var, &mut vars)?;
-            pattern.push_str(new_var);
-            pattern.push_str(remainder);
-            template = replace_in_template(template, var, new_var);
-        }
-
-        let template = try_expr_from_text(&template)
-            .ok_or(SsrError("Template is not an expression".into()))?
-            .syntax()
-            .clone();
-        let mut placeholders = FxHashMap::default();
-
-        traverse(&template, &mut |n| {
-            if let Some(v) = vars.iter().find(|v| v.0.as_str() == n.text()) {
-                placeholders.insert(n.clone(), v.clone());
-                false
-            } else {
-                true
-            }
-        });
-
-        let pattern = SsrPattern {
-            pattern: try_expr_from_text(&pattern)
-                .ok_or(SsrError("Pattern is not an expression".into()))?
-                .syntax()
-                .clone(),
-            vars,
-        };
-        let template = SsrTemplate { template, placeholders };
-        Ok(SsrQuery { pattern, template })
-    }
-}
-
-fn traverse(node: &SyntaxNode, go: &mut impl FnMut(&SyntaxNode) -> bool) {
-    if !go(node) {
-        return;
-    }
-    for ref child in node.children() {
-        traverse(child, go);
-    }
-}
-
-fn split_by_var(s: &str) -> Result<(&str, &str, &str), SsrError> {
-    let end_of_name = s.find(':').ok_or_else(|| SsrError("Use $<name>:expr".into()))?;
-    let name = &s[0..end_of_name];
-    is_name(name)?;
-    let type_begin = end_of_name + 1;
-    let type_length =
-        s[type_begin..].find(|c| !char::is_ascii_alphanumeric(&c)).unwrap_or_else(|| s.len());
-    let type_name = &s[type_begin..type_begin + type_length];
-    Ok((name, type_name, &s[type_begin + type_length..]))
-}
-
-fn is_name(s: &str) -> Result<(), SsrError> {
-    if s.chars().all(|c| c.is_ascii_alphanumeric() || c == '_') {
-        Ok(())
-    } else {
-        Err(SsrError("Name can contain only alphanumerics and _".into()))
-    }
-}
-
-fn is_expr(s: &str) -> Result<(), SsrError> {
-    if s == "expr" {
-        Ok(())
-    } else {
-        Err(SsrError("Only $<name>:expr is supported".into()))
-    }
-}
-
-fn replace_in_template(template: String, var: &str, new_var: &str) -> String {
-    let name = format!("${}", var);
-    template.replace(&name, new_var)
-}
-
-fn create_name<'a>(name: &str, vars: &'a mut Vec<Var>) -> Result<&'a str, SsrError> {
-    let sanitized_name = format!("__search_pattern_{}", name);
-    if vars.iter().any(|a| a.0 == sanitized_name) {
-        return Err(SsrError(format!("Name `{}` repeats more than once", name)));
-    }
-    vars.push(Var(sanitized_name));
-    Ok(&vars.last().unwrap().0)
-}
-
-fn find(pattern: &SsrPattern, code: &SyntaxNode) -> SsrMatches {
-    fn check_record_lit(
-        pattern: RecordLit,
-        code: RecordLit,
-        placeholders: &[Var],
-        match_: Match,
-    ) -> Option<Match> {
-        let match_ = check_opt_nodes(pattern.path(), code.path(), placeholders, match_)?;
-
-        let mut pattern_fields: Vec<RecordField> =
-            pattern.record_field_list().map(|x| x.fields().collect()).unwrap_or_default();
-        let mut code_fields: Vec<RecordField> =
-            code.record_field_list().map(|x| x.fields().collect()).unwrap_or_default();
-
-        if pattern_fields.len() != code_fields.len() {
-            return None;
-        }
-
-        let by_name = |a: &RecordField, b: &RecordField| {
-            a.name_ref()
-                .map(|x| x.syntax().text().to_string())
-                .cmp(&b.name_ref().map(|x| x.syntax().text().to_string()))
-        };
-        pattern_fields.sort_by(by_name);
-        code_fields.sort_by(by_name);
-
-        pattern_fields.into_iter().zip(code_fields.into_iter()).fold(
-            Some(match_),
-            |accum, (a, b)| {
-                accum.and_then(|match_| check_opt_nodes(Some(a), Some(b), placeholders, match_))
-            },
-        )
-    }
-
-    fn check_call_and_method_call(
-        pattern: CallExpr,
-        code: MethodCallExpr,
-        placeholders: &[Var],
-        match_: Match,
-    ) -> Option<Match> {
-        let (pattern_name, pattern_type_args) = if let Some(Expr::PathExpr(path_exr)) =
-            pattern.expr()
-        {
-            let segment = path_exr.path().and_then(|p| p.segment());
-            (segment.as_ref().and_then(|s| s.name_ref()), segment.and_then(|s| s.type_arg_list()))
-        } else {
-            (None, None)
-        };
-        let match_ = check_opt_nodes(pattern_name, code.name_ref(), placeholders, match_)?;
-        let match_ =
-            check_opt_nodes(pattern_type_args, code.type_arg_list(), placeholders, match_)?;
-        let pattern_args = pattern.syntax().children().find_map(ArgList::cast)?.args();
-        let code_args = code.syntax().children().find_map(ArgList::cast)?.args();
-        let code_args = once(code.expr()?).chain(code_args);
-        check_iter(pattern_args, code_args, placeholders, match_)
-    }
-
-    fn check_method_call_and_call(
-        pattern: MethodCallExpr,
-        code: CallExpr,
-        placeholders: &[Var],
-        match_: Match,
-    ) -> Option<Match> {
-        let (code_name, code_type_args) = if let Some(Expr::PathExpr(path_exr)) = code.expr() {
-            let segment = path_exr.path().and_then(|p| p.segment());
-            (segment.as_ref().and_then(|s| s.name_ref()), segment.and_then(|s| s.type_arg_list()))
-        } else {
-            (None, None)
-        };
-        let match_ = check_opt_nodes(pattern.name_ref(), code_name, placeholders, match_)?;
-        let match_ =
-            check_opt_nodes(pattern.type_arg_list(), code_type_args, placeholders, match_)?;
-        let code_args = code.syntax().children().find_map(ArgList::cast)?.args();
-        let pattern_args = pattern.syntax().children().find_map(ArgList::cast)?.args();
-        let pattern_args = once(pattern.expr()?).chain(pattern_args);
-        check_iter(pattern_args, code_args, placeholders, match_)
-    }
-
-    fn check_opt_nodes(
-        pattern: Option<impl AstNode>,
-        code: Option<impl AstNode>,
-        placeholders: &[Var],
-        match_: Match,
-    ) -> Option<Match> {
-        match (pattern, code) {
-            (Some(pattern), Some(code)) => check(
-                &pattern.syntax().clone().into(),
-                &code.syntax().clone().into(),
-                placeholders,
-                match_,
-            ),
-            (None, None) => Some(match_),
-            _ => None,
-        }
-    }
-
-    fn check_iter<T, I1, I2>(
-        mut pattern: I1,
-        mut code: I2,
-        placeholders: &[Var],
-        match_: Match,
-    ) -> Option<Match>
-    where
-        T: AstNode,
-        I1: Iterator<Item = T>,
-        I2: Iterator<Item = T>,
-    {
-        pattern
-            .by_ref()
-            .zip(code.by_ref())
-            .fold(Some(match_), |accum, (a, b)| {
-                accum.and_then(|match_| {
-                    check(
-                        &a.syntax().clone().into(),
-                        &b.syntax().clone().into(),
-                        placeholders,
-                        match_,
-                    )
-                })
-            })
-            .filter(|_| pattern.next().is_none() && code.next().is_none())
-    }
-
-    fn check(
-        pattern: &SyntaxElement,
-        code: &SyntaxElement,
-        placeholders: &[Var],
-        mut match_: Match,
-    ) -> Option<Match> {
-        match (&pattern, &code) {
-            (SyntaxElement::Token(pattern), SyntaxElement::Token(code)) => {
-                if pattern.text() == code.text() {
-                    Some(match_)
-                } else {
-                    None
-                }
-            }
-            (SyntaxElement::Node(pattern), SyntaxElement::Node(code)) => {
-                if placeholders.iter().any(|n| n.0.as_str() == pattern.text()) {
-                    match_.binding.insert(Var(pattern.text().to_string()), code.clone());
-                    Some(match_)
-                } else {
-                    if let (Some(pattern), Some(code)) =
-                        (RecordLit::cast(pattern.clone()), RecordLit::cast(code.clone()))
-                    {
-                        check_record_lit(pattern, code, placeholders, match_)
-                    } else if let (Some(pattern), Some(code)) =
-                        (CallExpr::cast(pattern.clone()), MethodCallExpr::cast(code.clone()))
-                    {
-                        check_call_and_method_call(pattern, code, placeholders, match_)
-                    } else if let (Some(pattern), Some(code)) =
-                        (MethodCallExpr::cast(pattern.clone()), CallExpr::cast(code.clone()))
-                    {
-                        check_method_call_and_call(pattern, code, placeholders, match_)
-                    } else {
-                        let mut pattern_children = pattern
-                            .children_with_tokens()
-                            .filter(|element| !element.kind().is_trivia());
-                        let mut code_children = code
-                            .children_with_tokens()
-                            .filter(|element| !element.kind().is_trivia());
-                        let new_ignored_comments =
-                            code.children_with_tokens().filter_map(|element| {
-                                element.as_token().and_then(|token| Comment::cast(token.clone()))
-                            });
-                        match_.ignored_comments.extend(new_ignored_comments);
-                        pattern_children
-                            .by_ref()
-                            .zip(code_children.by_ref())
-                            .fold(Some(match_), |accum, (a, b)| {
-                                accum.and_then(|match_| check(&a, &b, placeholders, match_))
-                            })
-                            .filter(|_| {
-                                pattern_children.next().is_none() && code_children.next().is_none()
-                            })
-                    }
-                }
-            }
-            _ => None,
-        }
-    }
-    let kind = pattern.pattern.kind();
-    let matches = code
-        .descendants()
-        .filter(|n| {
-            n.kind() == kind
-                || (kind == SyntaxKind::CALL_EXPR && n.kind() == SyntaxKind::METHOD_CALL_EXPR)
-                || (kind == SyntaxKind::METHOD_CALL_EXPR && n.kind() == SyntaxKind::CALL_EXPR)
-        })
-        .filter_map(|code| {
-            let match_ =
-                Match { place: code.clone(), binding: HashMap::new(), ignored_comments: vec![] };
-            check(&pattern.pattern.clone().into(), &code.into(), &pattern.vars, match_)
-        })
-        .collect();
-    SsrMatches { matches }
-}
-
-fn replace(matches: &SsrMatches, template: &SsrTemplate) -> TextEdit {
-    let mut builder = TextEditBuilder::default();
-    for match_ in &matches.matches {
-        builder.replace(
-            match_.place.text_range(),
-            render_replace(&match_.binding, &match_.ignored_comments, template),
-        );
-    }
-    builder.finish()
-}
-
-fn render_replace(
-    binding: &Binding,
-    ignored_comments: &Vec<Comment>,
-    template: &SsrTemplate,
-) -> String {
-    let edit = {
-        let mut builder = TextEditBuilder::default();
-        for element in template.template.descendants() {
-            if let Some(var) = template.placeholders.get(&element) {
-                builder.replace(element.text_range(), binding[var].to_string())
-            }
-        }
-        for comment in ignored_comments {
-            builder.insert(template.template.text_range().end(), comment.syntax().to_string())
-        }
-        builder.finish()
-    };
-
-    let mut text = template.template.text().to_string();
-    edit.apply(&mut text);
-    text
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use ra_syntax::SourceFile;
-
-    fn parse_error_text(query: &str) -> String {
-        format!("{}", query.parse::<SsrQuery>().unwrap_err())
-    }
-
-    #[test]
-    fn parser_happy_case() {
-        let result: SsrQuery = "foo($a:expr, $b:expr) ==>> bar($b, $a)".parse().unwrap();
-        assert_eq!(&result.pattern.pattern.text(), "foo(__search_pattern_a, __search_pattern_b)");
-        assert_eq!(result.pattern.vars.len(), 2);
-        assert_eq!(result.pattern.vars[0].0, "__search_pattern_a");
-        assert_eq!(result.pattern.vars[1].0, "__search_pattern_b");
-        assert_eq!(&result.template.template.text(), "bar(__search_pattern_b, __search_pattern_a)");
-    }
-
-    #[test]
-    fn parser_empty_query() {
-        assert_eq!(parse_error_text(""), "Parse error: Cannot find delemiter `==>>`");
-    }
-
-    #[test]
-    fn parser_no_delimiter() {
-        assert_eq!(parse_error_text("foo()"), "Parse error: Cannot find delemiter `==>>`");
-    }
-
-    #[test]
-    fn parser_two_delimiters() {
-        assert_eq!(
-            parse_error_text("foo() ==>> a ==>> b "),
-            "Parse error: More than one delimiter found"
-        );
-    }
-
-    #[test]
-    fn parser_no_pattern_type() {
-        assert_eq!(parse_error_text("foo($a) ==>>"), "Parse error: Use $<name>:expr");
-    }
-
-    #[test]
-    fn parser_invalid_name() {
-        assert_eq!(
-            parse_error_text("foo($a+:expr) ==>>"),
-            "Parse error: Name can contain only alphanumerics and _"
-        );
-    }
-
-    #[test]
-    fn parser_invalid_type() {
-        assert_eq!(
-            parse_error_text("foo($a:ident) ==>>"),
-            "Parse error: Only $<name>:expr is supported"
-        );
-    }
-
-    #[test]
-    fn parser_repeated_name() {
-        assert_eq!(
-            parse_error_text("foo($a:expr, $a:expr) ==>>"),
-            "Parse error: Name `a` repeats more than once"
-        );
-    }
-
-    #[test]
-    fn parser_invlid_pattern() {
-        assert_eq!(parse_error_text(" ==>> ()"), "Parse error: Pattern is not an expression");
-    }
-
-    #[test]
-    fn parser_invlid_template() {
-        assert_eq!(parse_error_text("() ==>> )"), "Parse error: Template is not an expression");
-    }
-
-    #[test]
-    fn parse_match_replace() {
-        let query: SsrQuery = "foo($x:expr) ==>> bar($x)".parse().unwrap();
-        let input = "fn main() { foo(1+2); }";
-
-        let code = SourceFile::parse(input).tree();
-        let matches = find(&query.pattern, code.syntax());
-        assert_eq!(matches.matches.len(), 1);
-        assert_eq!(matches.matches[0].place.text(), "foo(1+2)");
-        assert_eq!(matches.matches[0].binding.len(), 1);
-        assert_eq!(
-            matches.matches[0].binding[&Var("__search_pattern_x".to_string())].text(),
-            "1+2"
-        );
-
-        let edit = replace(&matches, &query.template);
-        let mut after = input.to_string();
-        edit.apply(&mut after);
-        assert_eq!(after, "fn main() { bar(1+2); }");
-    }
-
-    fn assert_ssr_transform(query: &str, input: &str, result: &str) {
-        let query: SsrQuery = query.parse().unwrap();
-        let code = SourceFile::parse(input).tree();
-        let matches = find(&query.pattern, code.syntax());
-        let edit = replace(&matches, &query.template);
-        let mut after = input.to_string();
-        edit.apply(&mut after);
-        assert_eq!(after, result);
-    }
-
-    #[test]
-    fn ssr_function_to_method() {
-        assert_ssr_transform(
-            "my_function($a:expr, $b:expr) ==>> ($a).my_method($b)",
-            "loop { my_function( other_func(x, y), z + w) }",
-            "loop { (other_func(x, y)).my_method(z + w) }",
-        )
-    }
-
-    #[test]
-    fn ssr_nested_function() {
-        assert_ssr_transform(
-            "foo($a:expr, $b:expr, $c:expr) ==>> bar($c, baz($a, $b))",
-            "fn main { foo  (x + value.method(b), x+y-z, true && false) }",
-            "fn main { bar(true && false, baz(x + value.method(b), x+y-z)) }",
-        )
-    }
-
-    #[test]
-    fn ssr_expected_spacing() {
-        assert_ssr_transform(
-            "foo($x:expr) + bar() ==>> bar($x)",
-            "fn main() { foo(5) + bar() }",
-            "fn main() { bar(5) }",
-        );
-    }
-
-    #[test]
-    fn ssr_with_extra_space() {
-        assert_ssr_transform(
-            "foo($x:expr  ) +    bar() ==>> bar($x)",
-            "fn main() { foo(  5 )  +bar(   ) }",
-            "fn main() { bar(5) }",
-        );
-    }
-
-    #[test]
-    fn ssr_keeps_nested_comment() {
-        assert_ssr_transform(
-            "foo($x:expr) ==>> bar($x)",
-            "fn main() { foo(other(5 /* using 5 */)) }",
-            "fn main() { bar(other(5 /* using 5 */)) }",
-        )
-    }
-
-    #[test]
-    fn ssr_keeps_comment() {
-        assert_ssr_transform(
-            "foo($x:expr) ==>> bar($x)",
-            "fn main() { foo(5 /* using 5 */) }",
-            "fn main() { bar(5)/* using 5 */ }",
-        )
-    }
-
-    #[test]
-    fn ssr_struct_lit() {
-        assert_ssr_transform(
-            "foo{a: $a:expr, b: $b:expr} ==>> foo::new($a, $b)",
-            "fn main() { foo{b:2, a:1} }",
-            "fn main() { foo::new(1, 2) }",
-        )
-    }
-
-    #[test]
-    fn ssr_call_and_method_call() {
-        assert_ssr_transform(
-            "foo::<'a>($a:expr, $b:expr)) ==>> foo2($a, $b)",
-            "fn main() { get().bar.foo::<'a>(1); }",
-            "fn main() { foo2(get().bar, 1); }",
-        )
-    }
-
-    #[test]
-    fn ssr_method_call_and_call() {
-        assert_ssr_transform(
-            "$o:expr.foo::<i32>($a:expr)) ==>> $o.foo2($a)",
-            "fn main() { X::foo::<i32>(x, 1); }",
-            "fn main() { x.foo2(1); }",
-        )
-    }
-}
diff --git a/crates/ra_ide/src/status.rs b/crates/ra_ide/src/status.rs
index 5b7992920..08e6f69cb 100644
--- a/crates/ra_ide/src/status.rs
+++ b/crates/ra_ide/src/status.rs
@@ -2,10 +2,7 @@ use std::{fmt, iter::FromIterator, sync::Arc};
 
 use hir::MacroFile;
 use ra_db::{
-    salsa::{
-        debug::{DebugQueryTable, TableEntry},
-        Database,
-    },
+    salsa::debug::{DebugQueryTable, TableEntry},
     FileTextQuery, SourceRootId,
 };
 use ra_ide_db::{
@@ -14,14 +11,15 @@ use ra_ide_db::{
 };
 use ra_prof::{memory_usage, Bytes};
 use ra_syntax::{ast, Parse, SyntaxNode};
+use rustc_hash::FxHashMap;
 
 use crate::FileId;
 
 fn syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
-    db.query(ra_db::ParseQuery).entries::<SyntaxTreeStats>()
+    ra_db::ParseQuery.in_db(db).entries::<SyntaxTreeStats>()
 }
 fn macro_syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
-    db.query(hir::db::ParseMacroQuery).entries::<SyntaxTreeStats>()
+    hir::db::ParseMacroQuery.in_db(db).entries::<SyntaxTreeStats>()
 }
 
 // Feature: Status
@@ -34,10 +32,10 @@ fn macro_syntax_tree_stats(db: &RootDatabase) -> SyntaxTreeStats {
 // | VS Code | **Rust Analyzer: Status**
 // |===
 pub(crate) fn status(db: &RootDatabase) -> String {
-    let files_stats = db.query(FileTextQuery).entries::<FilesStats>();
+    let files_stats = FileTextQuery.in_db(db).entries::<FilesStats>();
     let syntax_tree_stats = syntax_tree_stats(db);
     let macro_syntax_tree_stats = macro_syntax_tree_stats(db);
-    let symbols_stats = db.query(LibrarySymbolsQuery).entries::<LibrarySymbolsStats>();
+    let symbols_stats = LibrarySymbolsQuery.in_db(db).entries::<LibrarySymbolsStats>();
     format!(
         "{}\n{}\n{}\n{} (macros)\n\n\nmemory:\n{}\ngc {:?} seconds ago",
         files_stats,
@@ -123,20 +121,24 @@ struct LibrarySymbolsStats {
 
 impl fmt::Display for LibrarySymbolsStats {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "{} ({}) symbols", self.total, self.size,)
+        write!(fmt, "{} ({}) symbols", self.total, self.size)
     }
 }
 
-impl FromIterator<TableEntry<SourceRootId, Arc<SymbolIndex>>> for LibrarySymbolsStats {
+impl FromIterator<TableEntry<(), Arc<FxHashMap<SourceRootId, SymbolIndex>>>>
+    for LibrarySymbolsStats
+{
     fn from_iter<T>(iter: T) -> LibrarySymbolsStats
     where
-        T: IntoIterator<Item = TableEntry<SourceRootId, Arc<SymbolIndex>>>,
+        T: IntoIterator<Item = TableEntry<(), Arc<FxHashMap<SourceRootId, SymbolIndex>>>>,
     {
         let mut res = LibrarySymbolsStats::default();
         for entry in iter {
             let value = entry.value.unwrap();
-            res.total += value.len();
-            res.size += value.memory_size();
+            for symbols in value.values() {
+                res.total += symbols.len();
+                res.size += symbols.memory_size();
+            }
         }
         res
     }
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 0b53ebe69..6ac44c2c0 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -1,5 +1,6 @@
 mod tags;
 mod html;
+mod injection;
 #[cfg(test)]
 mod tests;
 
@@ -10,14 +11,14 @@ use ra_ide_db::{
 };
 use ra_prof::profile;
 use ra_syntax::{
-    ast::{self, HasFormatSpecifier, HasQuotes, HasStringValue},
+    ast::{self, HasFormatSpecifier},
     AstNode, AstToken, Direction, NodeOrToken, SyntaxElement,
     SyntaxKind::*,
-    SyntaxToken, TextRange, WalkEvent, T,
+    TextRange, WalkEvent, T,
 };
 use rustc_hash::FxHashMap;
 
-use crate::{call_info::ActiveParameter, Analysis, FileId};
+use crate::FileId;
 
 use ast::FormatSpecifier;
 pub(crate) use html::highlight_as_html;
@@ -43,6 +44,7 @@ pub(crate) fn highlight(
     db: &RootDatabase,
     file_id: FileId,
     range_to_highlight: Option<TextRange>,
+    syntactic_name_ref_highlighting: bool,
 ) -> Vec<HighlightedRange> {
     let _p = profile("highlight");
     let sema = Semantics::new(db);
@@ -103,6 +105,7 @@ pub(crate) fn highlight(
                     if let Some((highlight, binding_hash)) = highlight_element(
                         &sema,
                         &mut bindings_shadow_count,
+                        syntactic_name_ref_highlighting,
                         name.syntax().clone().into(),
                     ) {
                         stack.add(HighlightedRange {
@@ -118,7 +121,23 @@ pub(crate) fn highlight(
                 assert!(current_macro_call == Some(mc));
                 current_macro_call = None;
                 format_string = None;
-                continue;
+            }
+            _ => (),
+        }
+
+        // Check for Rust code in documentation
+        match &event {
+            WalkEvent::Leave(NodeOrToken::Node(node)) => {
+                if let Some((doctest, range_mapping, new_comments)) =
+                    injection::extract_doc_comments(node)
+                {
+                    injection::highlight_doc_comment(
+                        doctest,
+                        range_mapping,
+                        new_comments,
+                        &mut stack,
+                    );
+                }
             }
             _ => (),
         }
@@ -130,7 +149,7 @@ pub(crate) fn highlight(
 
         let range = element.text_range();
 
-        let element_to_highlight = if current_macro_call.is_some() {
+        let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
             // Inside a macro -- expand it first
             let token = match element.clone().into_token() {
                 Some(it) if it.parent().kind() == TOKEN_TREE => it,
@@ -142,23 +161,25 @@ pub(crate) fn highlight(
             // Check if macro takes a format string and remember it for highlighting later.
             // The macros that accept a format string expand to a compiler builtin macros
             // `format_args` and `format_args_nl`.
-            if let Some(fmt_macro_call) = parent.parent().and_then(ast::MacroCall::cast) {
-                if let Some(name) =
-                    fmt_macro_call.path().and_then(|p| p.segment()).and_then(|s| s.name_ref())
-                {
-                    match name.text().as_str() {
-                        "format_args" | "format_args_nl" => {
-                            format_string = parent
-                                .children_with_tokens()
-                                .filter(|t| t.kind() != WHITESPACE)
-                                .nth(1)
-                                .filter(|e| {
-                                    ast::String::can_cast(e.kind())
-                                        || ast::RawString::can_cast(e.kind())
-                                })
-                        }
-                        _ => {}
+            if let Some(name) = parent
+                .parent()
+                .and_then(ast::MacroCall::cast)
+                .and_then(|mc| mc.path())
+                .and_then(|p| p.segment())
+                .and_then(|s| s.name_ref())
+            {
+                match name.text().as_str() {
+                    "format_args" | "format_args_nl" => {
+                        format_string = parent
+                            .children_with_tokens()
+                            .filter(|t| t.kind() != WHITESPACE)
+                            .nth(1)
+                            .filter(|e| {
+                                ast::String::can_cast(e.kind())
+                                    || ast::RawString::can_cast(e.kind())
+                            })
                     }
+                    _ => {}
                 }
             }
 
@@ -173,22 +194,25 @@ pub(crate) fn highlight(
 
         if let Some(token) = element.as_token().cloned().and_then(ast::RawString::cast) {
             let expanded = element_to_highlight.as_token().unwrap().clone();
-            if highlight_injection(&mut stack, &sema, token, expanded).is_some() {
+            if injection::highlight_injection(&mut stack, &sema, token, expanded).is_some() {
                 continue;
             }
         }
 
         let is_format_string = format_string.as_ref() == Some(&element_to_highlight);
 
-        if let Some((highlight, binding_hash)) =
-            highlight_element(&sema, &mut bindings_shadow_count, element_to_highlight.clone())
-        {
+        if let Some((highlight, binding_hash)) = highlight_element(
+            &sema,
+            &mut bindings_shadow_count,
+            syntactic_name_ref_highlighting,
+            element_to_highlight.clone(),
+        ) {
             stack.add(HighlightedRange { range, highlight, binding_hash });
             if let Some(string) =
                 element_to_highlight.as_token().cloned().and_then(ast::String::cast)
             {
-                stack.push();
                 if is_format_string {
+                    stack.push();
                     string.lex_format_specifier(|piece_range, kind| {
                         if let Some(highlight) = highlight_format_specifier(kind) {
                             stack.add(HighlightedRange {
@@ -198,13 +222,27 @@ pub(crate) fn highlight(
                             });
                         }
                     });
+                    stack.pop();
+                }
+                // Highlight escape sequences
+                if let Some(char_ranges) = string.char_ranges() {
+                    stack.push();
+                    for (piece_range, _) in char_ranges.iter().filter(|(_, char)| char.is_ok()) {
+                        if string.text()[piece_range.start().into()..].starts_with('\\') {
+                            stack.add(HighlightedRange {
+                                range: piece_range + range.start(),
+                                highlight: HighlightTag::EscapeSequence.into(),
+                                binding_hash: None,
+                            });
+                        }
+                    }
+                    stack.pop_and_inject(None);
                 }
-                stack.pop();
             } else if let Some(string) =
                 element_to_highlight.as_token().cloned().and_then(ast::RawString::cast)
             {
-                stack.push();
                 if is_format_string {
+                    stack.push();
                     string.lex_format_specifier(|piece_range, kind| {
                         if let Some(highlight) = highlight_format_specifier(kind) {
                             stack.add(HighlightedRange {
@@ -214,8 +252,8 @@ pub(crate) fn highlight(
                             });
                         }
                     });
+                    stack.pop();
                 }
-                stack.pop();
             }
         }
     }
@@ -259,9 +297,8 @@ impl HighlightedRangeStack {
             let mut parent = prev.pop().unwrap();
             for ele in children {
                 assert!(parent.range.contains_range(ele.range));
-                let mut cloned = parent.clone();
-                parent.range = TextRange::new(parent.range.start(), ele.range.start());
-                cloned.range = TextRange::new(ele.range.end(), cloned.range.end());
+
+                let cloned = Self::intersect(&mut parent, &ele);
                 if !parent.range.is_empty() {
                     prev.push(parent);
                 }
@@ -274,6 +311,92 @@ impl HighlightedRangeStack {
         }
     }
 
+    /// Intersects the `HighlightedRange` `parent` with `child`.
+    /// `parent` is mutated in place, becoming the range before `child`.
+    /// Returns the range (of the same type as `parent`) *after* `child`.
+    fn intersect(parent: &mut HighlightedRange, child: &HighlightedRange) -> HighlightedRange {
+        assert!(parent.range.contains_range(child.range));
+
+        let mut cloned = parent.clone();
+        parent.range = TextRange::new(parent.range.start(), child.range.start());
+        cloned.range = TextRange::new(child.range.end(), cloned.range.end());
+
+        cloned
+    }
+
+    /// Remove the `HighlightRange` of `parent` that's currently covered by `child`.
+    fn intersect_partial(parent: &mut HighlightedRange, child: &HighlightedRange) {
+        assert!(
+            parent.range.start() <= child.range.start()
+                && parent.range.end() >= child.range.start()
+                && child.range.end() > parent.range.end()
+        );
+
+        parent.range = TextRange::new(parent.range.start(), child.range.start());
+    }
+
+    /// Similar to `pop`, but can modify arbitrary prior ranges (where `pop`)
+    /// can only modify the last range currently on the stack.
+    /// Can be used to do injections that span multiple ranges, like the
+    /// doctest injection below.
+    /// If `overwrite_parent` is non-optional, the highlighting of the parent range
+    /// is overwritten with the argument.
+    ///
+    /// Note that `pop` can be simulated by `pop_and_inject(false)` but the
+    /// latter is computationally more expensive.
+    fn pop_and_inject(&mut self, overwrite_parent: Option<Highlight>) {
+        let mut children = self.stack.pop().unwrap();
+        let prev = self.stack.last_mut().unwrap();
+        children.sort_by_key(|range| range.range.start());
+        prev.sort_by_key(|range| range.range.start());
+
+        for child in children {
+            if let Some(idx) =
+                prev.iter().position(|parent| parent.range.contains_range(child.range))
+            {
+                if let Some(tag) = overwrite_parent {
+                    prev[idx].highlight = tag;
+                }
+
+                let cloned = Self::intersect(&mut prev[idx], &child);
+                let insert_idx = if prev[idx].range.is_empty() {
+                    prev.remove(idx);
+                    idx
+                } else {
+                    idx + 1
+                };
+                prev.insert(insert_idx, child);
+                if !cloned.range.is_empty() {
+                    prev.insert(insert_idx + 1, cloned);
+                }
+            } else {
+                let maybe_idx =
+                    prev.iter().position(|parent| parent.range.contains(child.range.start()));
+                match (overwrite_parent, maybe_idx) {
+                    (Some(_), Some(idx)) => {
+                        Self::intersect_partial(&mut prev[idx], &child);
+                        let insert_idx = if prev[idx].range.is_empty() {
+                            prev.remove(idx);
+                            idx
+                        } else {
+                            idx + 1
+                        };
+                        prev.insert(insert_idx, child);
+                    }
+                    (_, None) => {
+                        let idx = prev
+                            .binary_search_by_key(&child.range.start(), |range| range.range.start())
+                            .unwrap_or_else(|x| x);
+                        prev.insert(idx, child);
+                    }
+                    _ => {
+                        unreachable!("child range should be completely contained in parent range");
+                    }
+                }
+            }
+        }
+    }
+
     fn add(&mut self, range: HighlightedRange) {
         self.stack
             .last_mut()
@@ -335,6 +458,7 @@ fn macro_call_range(macro_call: &ast::MacroCall) -> Option<TextRange> {
 fn highlight_element(
     sema: &Semantics<RootDatabase>,
     bindings_shadow_count: &mut FxHashMap<Name, u32>,
+    syntactic_name_ref_highlighting: bool,
     element: SyntaxElement,
 ) -> Option<(Highlight, Option<u64>)> {
     let db = sema.db;
@@ -363,6 +487,7 @@ fn highlight_element(
                     highlight_name(db, def) | HighlightModifier::Definition
                 }
                 Some(NameClass::ConstReference(def)) => highlight_name(db, def),
+                Some(NameClass::FieldShorthand { .. }) => HighlightTag::Field.into(),
                 None => highlight_name_by_syntax(name) | HighlightModifier::Definition,
             }
         }
@@ -387,12 +512,20 @@ fn highlight_element(
                     }
                     NameRefClass::FieldShorthand { .. } => HighlightTag::Field.into(),
                 },
+                None if syntactic_name_ref_highlighting => highlight_name_ref_by_syntax(name_ref),
                 None => HighlightTag::UnresolvedReference.into(),
             }
         }
 
         // Simple token-based highlighting
-        COMMENT => HighlightTag::Comment.into(),
+        COMMENT => {
+            let comment = element.into_token().and_then(ast::Comment::cast)?;
+            let h = HighlightTag::Comment;
+            match comment.kind().doc {
+                Some(_) => h | HighlightModifier::Documentation,
+                None => h.into(),
+            }
+        }
         STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => HighlightTag::StringLiteral.into(),
         ATTR => HighlightTag::Attribute.into(),
         INT_NUMBER | FLOAT_NUMBER => HighlightTag::NumericLiteral.into(),
@@ -406,6 +539,21 @@ fn highlight_element(
                 _ => h,
             }
         }
+        T![*] => {
+            let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
+
+            let expr = prefix_expr.expr()?;
+            let ty = sema.type_of_expr(&expr)?;
+            if !ty.is_raw_ptr() {
+                return None;
+            } else {
+                HighlightTag::Operator | HighlightModifier::Unsafe
+            }
+        }
+        T![!] if element.parent().and_then(ast::MacroCall::cast).is_some() => {
+            Highlight::new(HighlightTag::Macro)
+        }
+        p if p.is_punct() => HighlightTag::Punctuation.into(),
 
         k if k.is_keyword() => {
             let h = Highlight::new(HighlightTag::Keyword);
@@ -419,10 +567,31 @@ fn highlight_element(
                 | T![return]
                 | T![while]
                 | T![in] => h | HighlightModifier::ControlFlow,
-                T![for] if !is_child_of_impl(element) => h | HighlightModifier::ControlFlow,
+                T![for] if !is_child_of_impl(&element) => h | HighlightModifier::ControlFlow,
                 T![unsafe] => h | HighlightModifier::Unsafe,
                 T![true] | T![false] => HighlightTag::BoolLiteral.into(),
-                T![self] => HighlightTag::SelfKeyword.into(),
+                T![self] => {
+                    let self_param_is_mut = element
+                        .parent()
+                        .and_then(ast::SelfParam::cast)
+                        .and_then(|p| p.mut_token())
+                        .is_some();
+                    // closure to enforce lazyness
+                    let self_path = || {
+                        sema.resolve_path(&element.parent()?.parent().and_then(ast::Path::cast)?)
+                    };
+                    if self_param_is_mut
+                        || matches!(self_path(),
+                            Some(hir::PathResolution::Local(local))
+                                if local.is_self(db)
+                                    && (local.is_mut(db) || local.ty(db).is_mutable_reference())
+                        )
+                    {
+                        HighlightTag::SelfKeyword | HighlightModifier::Mutable
+                    } else {
+                        HighlightTag::SelfKeyword.into()
+                    }
+                }
                 _ => h,
             }
         }
@@ -445,7 +614,7 @@ fn highlight_element(
     }
 }
 
-fn is_child_of_impl(element: SyntaxElement) -> bool {
+fn is_child_of_impl(element: &SyntaxElement) -> bool {
     match element.parent() {
         Some(e) => e.kind() == IMPL_DEF,
         _ => false,
@@ -458,7 +627,13 @@ fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
         Definition::Field(_) => HighlightTag::Field,
         Definition::ModuleDef(def) => match def {
             hir::ModuleDef::Module(_) => HighlightTag::Module,
-            hir::ModuleDef::Function(_) => HighlightTag::Function,
+            hir::ModuleDef::Function(func) => {
+                let mut h = HighlightTag::Function.into();
+                if func.is_unsafe(db) {
+                    h |= HighlightModifier::Unsafe;
+                }
+                return h;
+            }
             hir::ModuleDef::Adt(hir::Adt::Struct(_)) => HighlightTag::Struct,
             hir::ModuleDef::Adt(hir::Adt::Enum(_)) => HighlightTag::Enum,
             hir::ModuleDef::Adt(hir::Adt::Union(_)) => HighlightTag::Union,
@@ -477,9 +652,10 @@ fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
         },
         Definition::SelfType(_) => HighlightTag::SelfType,
         Definition::TypeParam(_) => HighlightTag::TypeParam,
-        // FIXME: distinguish between locals and parameters
         Definition::Local(local) => {
-            let mut h = Highlight::new(HighlightTag::Local);
+            let tag =
+                if local.is_param(db) { HighlightTag::ValueParam } else { HighlightTag::Local };
+            let mut h = Highlight::new(tag);
             if local.is_mut(db) || local.ty(db).is_mutable_reference() {
                 h |= HighlightModifier::Mutable;
             }
@@ -517,41 +693,52 @@ fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
     tag.into()
 }
 
-fn highlight_injection(
-    acc: &mut HighlightedRangeStack,
-    sema: &Semantics<RootDatabase>,
-    literal: ast::RawString,
-    expanded: SyntaxToken,
-) -> Option<()> {
-    let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
-    if !active_parameter.name.starts_with("ra_fixture") {
-        return None;
-    }
-    let value = literal.value()?;
-    let (analysis, tmp_file_id) = Analysis::from_single_file(value);
-
-    if let Some(range) = literal.open_quote_text_range() {
-        acc.add(HighlightedRange {
-            range,
-            highlight: HighlightTag::StringLiteral.into(),
-            binding_hash: None,
-        })
-    }
+fn highlight_name_ref_by_syntax(name: ast::NameRef) -> Highlight {
+    let default = HighlightTag::UnresolvedReference;
 
-    for mut h in analysis.highlight(tmp_file_id).unwrap() {
-        if let Some(r) = literal.map_range_up(h.range) {
-            h.range = r;
-            acc.add(h)
-        }
-    }
+    let parent = match name.syntax().parent() {
+        Some(it) => it,
+        _ => return default.into(),
+    };
 
-    if let Some(range) = literal.close_quote_text_range() {
-        acc.add(HighlightedRange {
-            range,
-            highlight: HighlightTag::StringLiteral.into(),
-            binding_hash: None,
-        })
-    }
+    let tag = match parent.kind() {
+        METHOD_CALL_EXPR => HighlightTag::Function,
+        FIELD_EXPR => HighlightTag::Field,
+        PATH_SEGMENT => {
+            let path = match parent.parent().and_then(ast::Path::cast) {
+                Some(it) => it,
+                _ => return default.into(),
+            };
+            let expr = match path.syntax().parent().and_then(ast::PathExpr::cast) {
+                Some(it) => it,
+                _ => {
+                    // within path, decide whether it is module or adt by checking for uppercase name
+                    return if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                        HighlightTag::Struct
+                    } else {
+                        HighlightTag::Module
+                    }
+                    .into();
+                }
+            };
+            let parent = match expr.syntax().parent() {
+                Some(it) => it,
+                None => return default.into(),
+            };
 
-    Some(())
+            match parent.kind() {
+                CALL_EXPR => HighlightTag::Function,
+                _ => {
+                    if name.text().chars().next().unwrap_or_default().is_uppercase() {
+                        HighlightTag::Struct
+                    } else {
+                        HighlightTag::Constant
+                    }
+                }
+            }
+        }
+        _ => default,
+    };
+
+    tag.into()
 }
diff --git a/crates/ra_ide/src/syntax_highlighting/html.rs b/crates/ra_ide/src/syntax_highlighting/html.rs
index edfe61f39..0be55bca9 100644
--- a/crates/ra_ide/src/syntax_highlighting/html.rs
+++ b/crates/ra_ide/src/syntax_highlighting/html.rs
@@ -19,7 +19,7 @@ pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId, rainbow: boo
         )
     }
 
-    let ranges = highlight(db, file_id, None);
+    let ranges = highlight(db, file_id, None, false);
     let text = parse.tree().syntax().to_string();
     let mut prev_pos = TextSize::from(0);
     let mut buf = String::new();
@@ -64,11 +64,15 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 
 .lifetime           { color: #DFAF8F; font-style: italic; }
 .comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
 .struct, .enum      { color: #7CB8BB; }
 .enum_variant       { color: #BDE0F3; }
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
@@ -79,12 +83,15 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .bool_literal       { color: #BFE6EB; }
 .macro              { color: #94BFF3; }
 .module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
-
+.escape_sequence    { color: #94BFF3; }
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
 .control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
 </style>
 ";
diff --git a/crates/ra_ide/src/syntax_highlighting/injection.rs b/crates/ra_ide/src/syntax_highlighting/injection.rs
new file mode 100644
index 000000000..8665b480f
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/injection.rs
@@ -0,0 +1,188 @@
+//! Syntax highlighting injections such as highlighting of documentation tests.
+
+use std::{collections::BTreeMap, convert::TryFrom};
+
+use ast::{HasQuotes, HasStringValue};
+use hir::Semantics;
+use ra_syntax::{ast, AstToken, SyntaxNode, SyntaxToken, TextRange, TextSize};
+use stdx::SepBy;
+
+use crate::{
+    call_info::ActiveParameter, Analysis, Highlight, HighlightModifier, HighlightTag,
+    HighlightedRange, RootDatabase,
+};
+
+use super::HighlightedRangeStack;
+
+pub(super) fn highlight_injection(
+    acc: &mut HighlightedRangeStack,
+    sema: &Semantics<RootDatabase>,
+    literal: ast::RawString,
+    expanded: SyntaxToken,
+) -> Option<()> {
+    let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
+    if !active_parameter.name.starts_with("ra_fixture") {
+        return None;
+    }
+    let value = literal.value()?;
+    let (analysis, tmp_file_id) = Analysis::from_single_file(value.into_owned());
+
+    if let Some(range) = literal.open_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    for mut h in analysis.highlight(tmp_file_id).unwrap() {
+        if let Some(r) = literal.map_range_up(h.range) {
+            h.range = r;
+            acc.add(h)
+        }
+    }
+
+    if let Some(range) = literal.close_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    Some(())
+}
+
+/// Mapping from extracted documentation code to original code
+type RangesMap = BTreeMap<TextSize, TextSize>;
+
+const RUSTDOC_FENCE: &'static str = "```";
+const RUSTDOC_FENCE_TOKENS: &[&'static str] =
+    &["", "rust", "should_panic", "ignore", "no_run", "compile_fail", "edition2015", "edition2018"];
+
+/// Extracts Rust code from documentation comments as well as a mapping from
+/// the extracted source code back to the original source ranges.
+/// Lastly, a vector of new comment highlight ranges (spanning only the
+/// comment prefix) is returned which is used in the syntax highlighting
+/// injection to replace the previous (line-spanning) comment ranges.
+pub(super) fn extract_doc_comments(
+    node: &SyntaxNode,
+) -> Option<(String, RangesMap, Vec<HighlightedRange>)> {
+    // wrap the doctest into function body to get correct syntax highlighting
+    let prefix = "fn doctest() {\n";
+    let suffix = "}\n";
+    // Mapping from extracted documentation code to original code
+    let mut range_mapping: RangesMap = BTreeMap::new();
+    let mut line_start = TextSize::try_from(prefix.len()).unwrap();
+    let mut is_codeblock = false;
+    let mut is_doctest = false;
+    // Replace the original, line-spanning comment ranges by new, only comment-prefix
+    // spanning comment ranges.
+    let mut new_comments = Vec::new();
+    let doctest = node
+        .children_with_tokens()
+        .filter_map(|el| el.into_token().and_then(ast::Comment::cast))
+        .filter(|comment| comment.kind().doc.is_some())
+        .filter(|comment| {
+            if let Some(idx) = comment.text().find(RUSTDOC_FENCE) {
+                is_codeblock = !is_codeblock;
+                // Check whether code is rust by inspecting fence guards
+                let guards = &comment.text()[idx + RUSTDOC_FENCE.len()..];
+                let is_rust =
+                    guards.split(',').all(|sub| RUSTDOC_FENCE_TOKENS.contains(&sub.trim()));
+                is_doctest = is_codeblock && is_rust;
+                false
+            } else {
+                is_doctest
+            }
+        })
+        .map(|comment| {
+            let prefix_len = comment.prefix().len();
+            let line: &str = comment.text().as_str();
+            let range = comment.syntax().text_range();
+
+            // whitespace after comment is ignored
+            let pos = if let Some(ws) = line.chars().nth(prefix_len).filter(|c| c.is_whitespace()) {
+                prefix_len + ws.len_utf8()
+            } else {
+                prefix_len
+            };
+
+            // lines marked with `#` should be ignored in output, we skip the `#` char
+            let pos = if let Some(ws) = line.chars().nth(pos).filter(|&c| c == '#') {
+                pos + ws.len_utf8()
+            } else {
+                pos
+            };
+
+            range_mapping.insert(line_start, range.start() + TextSize::try_from(pos).unwrap());
+            new_comments.push(HighlightedRange {
+                range: TextRange::new(
+                    range.start(),
+                    range.start() + TextSize::try_from(pos).unwrap(),
+                ),
+                highlight: HighlightTag::Comment | HighlightModifier::Documentation,
+                binding_hash: None,
+            });
+            line_start += range.len() - TextSize::try_from(pos).unwrap();
+            line_start += TextSize::try_from('\n'.len_utf8()).unwrap();
+
+            line[pos..].to_owned()
+        })
+        .sep_by("\n")
+        .to_string();
+
+    if doctest.is_empty() {
+        return None;
+    }
+
+    let doctest = format!("{}{}{}", prefix, doctest, suffix);
+    Some((doctest, range_mapping, new_comments))
+}
+
+/// Injection of syntax highlighting of doctests.
+pub(super) fn highlight_doc_comment(
+    text: String,
+    range_mapping: RangesMap,
+    new_comments: Vec<HighlightedRange>,
+    stack: &mut HighlightedRangeStack,
+) {
+    let (analysis, tmp_file_id) = Analysis::from_single_file(text);
+
+    stack.push();
+    for mut h in analysis.with_db(|db| super::highlight(db, tmp_file_id, None, true)).unwrap() {
+        // Determine start offset and end offset in case of multi-line ranges
+        let mut start_offset = None;
+        let mut end_offset = None;
+        for (line_start, orig_line_start) in range_mapping.range(..h.range.end()).rev() {
+            // It's possible for orig_line_start - line_start to be negative. Add h.range.start()
+            // here and remove it from the end range after the loop below so that the values are
+            // always non-negative.
+            let offset = h.range.start() + orig_line_start - line_start;
+            if line_start <= &h.range.start() {
+                start_offset.get_or_insert(offset);
+                break;
+            } else {
+                end_offset.get_or_insert(offset);
+            }
+        }
+        if let Some(start_offset) = start_offset {
+            h.range = TextRange::new(
+                start_offset,
+                h.range.end() + end_offset.unwrap_or(start_offset) - h.range.start(),
+            );
+
+            h.highlight |= HighlightModifier::Injected;
+            stack.add(h);
+        }
+    }
+
+    // Inject the comment prefix highlight ranges
+    stack.push();
+    for comment in new_comments {
+        stack.add(comment);
+    }
+    stack.pop_and_inject(None);
+    stack
+        .pop_and_inject(Some(Highlight::from(HighlightTag::Generic) | HighlightModifier::Injected));
+}
diff --git a/crates/ra_ide/src/syntax_highlighting/tags.rs b/crates/ra_ide/src/syntax_highlighting/tags.rs
index 1514531de..49ec94bdc 100644
--- a/crates/ra_ide/src/syntax_highlighting/tags.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tags.rs
@@ -23,13 +23,16 @@ pub enum HighlightTag {
     Constant,
     Enum,
     EnumVariant,
+    EscapeSequence,
     Field,
     Function,
+    Generic,
     Keyword,
     Lifetime,
     Macro,
     Module,
     NumericLiteral,
+    Punctuation,
     SelfKeyword,
     SelfType,
     Static,
@@ -39,6 +42,7 @@ pub enum HighlightTag {
     TypeAlias,
     TypeParam,
     Union,
+    ValueParam,
     Local,
     UnresolvedReference,
     FormatSpecifier,
@@ -55,6 +59,8 @@ pub enum HighlightModifier {
     /// `foo` in `fn foo(x: i32)` is a definition, `foo` in `foo(90 + 2)` is
     /// not.
     Definition,
+    Documentation,
+    Injected,
     Mutable,
     Unsafe,
 }
@@ -71,13 +77,18 @@ impl HighlightTag {
             HighlightTag::Constant => "constant",
             HighlightTag::Enum => "enum",
             HighlightTag::EnumVariant => "enum_variant",
+            HighlightTag::EscapeSequence => "escape_sequence",
             HighlightTag::Field => "field",
+            HighlightTag::FormatSpecifier => "format_specifier",
             HighlightTag::Function => "function",
+            HighlightTag::Generic => "generic",
             HighlightTag::Keyword => "keyword",
             HighlightTag::Lifetime => "lifetime",
+            HighlightTag::Punctuation => "punctuation",
             HighlightTag::Macro => "macro",
             HighlightTag::Module => "module",
             HighlightTag::NumericLiteral => "numeric_literal",
+            HighlightTag::Operator => "operator",
             HighlightTag::SelfKeyword => "self_keyword",
             HighlightTag::SelfType => "self_type",
             HighlightTag::Static => "static",
@@ -87,10 +98,9 @@ impl HighlightTag {
             HighlightTag::TypeAlias => "type_alias",
             HighlightTag::TypeParam => "type_param",
             HighlightTag::Union => "union",
+            HighlightTag::ValueParam => "value_param",
             HighlightTag::Local => "variable",
             HighlightTag::UnresolvedReference => "unresolved_reference",
-            HighlightTag::FormatSpecifier => "format_specifier",
-            HighlightTag::Operator => "operator",
         }
     }
 }
@@ -106,6 +116,8 @@ impl HighlightModifier {
         HighlightModifier::Attribute,
         HighlightModifier::ControlFlow,
         HighlightModifier::Definition,
+        HighlightModifier::Documentation,
+        HighlightModifier::Injected,
         HighlightModifier::Mutable,
         HighlightModifier::Unsafe,
     ];
@@ -115,6 +127,8 @@ impl HighlightModifier {
             HighlightModifier::Attribute => "attribute",
             HighlightModifier::ControlFlow => "control",
             HighlightModifier::Definition => "declaration",
+            HighlightModifier::Documentation => "documentation",
+            HighlightModifier::Injected => "injected",
             HighlightModifier::Mutable => "mutable",
             HighlightModifier::Unsafe => "unsafe",
         }
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
index eb43a23da..87a6e2523 100644
--- a/crates/ra_ide/src/syntax_highlighting/tests.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -1,15 +1,13 @@
 use std::fs;
 
-use test_utils::{assert_eq_text, project_dir, read_text};
+use expect::{expect_file, ExpectFile};
+use test_utils::project_dir;
 
-use crate::{
-    mock_analysis::{single_file, MockAnalysis},
-    FileRange, TextRange,
-};
+use crate::{mock_analysis::single_file, FileRange, TextRange};
 
 #[test]
 fn test_highlighting() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 #[derive(Clone, Debug)]
 struct Foo {
@@ -27,6 +25,16 @@ impl Bar for Foo {
     }
 }
 
+impl Foo {
+    fn baz(mut self) -> i32 {
+        self.x
+    }
+
+    fn qux(&mut self) {
+        self.x = 0;
+    }
+}
+
 static mut STATIC_MUT: i32 = 0;
 
 fn foo<'a, T>() -> T {
@@ -43,6 +51,12 @@ def_fn! {
     }
 }
 
+macro_rules! noop {
+    ($expr:expr) => {
+        $expr
+    }
+}
+
 // comment
 fn main() {
     println!("Hello, {}!", 92);
@@ -61,10 +75,14 @@ fn main() {
         // Do nothing
     }
 
+    noop!(noop!(1));
+
     let mut x = 42;
     let y = &mut x;
     let z = &y;
 
+    let Foo { x: z, y } = Foo { x: z, y };
+
     y;
 }
 
@@ -84,17 +102,14 @@ impl<T> Option<T> {
 }
 "#
         .trim(),
+        expect_file!["crates/ra_ide/test_data/highlighting.html"],
+        false,
     );
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlighting.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
 fn test_rainbow_highlighting() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 fn main() {
     let hello = "hello";
@@ -110,12 +125,9 @@ fn bar() {
 }
 "#
         .trim(),
+        expect_file!["crates/ra_ide/test_data/rainbow_highlighting.html"],
+        true,
     );
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/rainbow_highlighting.html");
-    let actual_html = &analysis.highlight_as_html(file_id, true).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
@@ -123,12 +135,10 @@ fn accidentally_quadratic() {
     let file = project_dir().join("crates/ra_syntax/test_data/accidentally_quadratic");
     let src = fs::read_to_string(file).unwrap();
 
-    let mut mock = MockAnalysis::new();
-    let file_id = mock.add_file("/main.rs", &src);
-    let host = mock.analysis_host();
+    let (analysis, file_id) = single_file(&src);
 
     // let t = std::time::Instant::now();
-    let _ = host.analysis().highlight(file_id).unwrap();
+    let _ = analysis.highlight(file_id).unwrap();
     // eprintln!("elapsed: {:?}", t.elapsed());
 }
 
@@ -136,16 +146,17 @@ fn accidentally_quadratic() {
 fn test_ranges() {
     let (analysis, file_id) = single_file(
         r#"
-            #[derive(Clone, Debug)]
-            struct Foo {
-                pub x: i32,
-                pub y: i32,
-            }"#,
+#[derive(Clone, Debug)]
+struct Foo {
+    pub x: i32,
+    pub y: i32,
+}
+"#,
     );
 
     // The "x"
     let highlights = &analysis
-        .highlight_range(FileRange { file_id, range: TextRange::at(82.into(), 1.into()) })
+        .highlight_range(FileRange { file_id, range: TextRange::at(45.into(), 1.into()) })
         .unwrap();
 
     assert_eq!(&highlights[0].highlight.to_string(), "field.declaration");
@@ -153,7 +164,7 @@ fn test_ranges() {
 
 #[test]
 fn test_flattening() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r##"
 fn fixture(ra_fixture: &str) {}
 
@@ -167,13 +178,9 @@ fn main() {
     );
 }"##
         .trim(),
+        expect_file!["crates/ra_ide/test_data/highlight_injection.html"],
+        false,
     );
-
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlight_injection.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
@@ -192,7 +199,7 @@ macro_rules! test {}
 fn test_string_highlighting() {
     // The format string detection is based on macro-expansion,
     // thus, we have to copy the macro definition from `std`
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 macro_rules! println {
     ($($arg:tt)*) => ({
@@ -218,6 +225,7 @@ fn main() {
     println!("{argument}", argument = "test");   // => "test"
     println!("{name} {}", 1, name = 2);          // => "2 1"
     println!("{a} {c} {b}", a="a", b='b', c=3);  // => "a 3 b"
+    println!("{{{}}}", 2);                       // => "{2}"
     println!("Hello {:5}!", "x");
     println!("Hello {:1$}!", "x", 5);
     println!("Hello {1:0$}!", 5, "x");
@@ -245,15 +253,128 @@ fn main() {
 
     println!(r"Hello, {}!", "world");
 
+    // escape sequences
+    println!("Hello\nWorld");
+    println!("\u{48}\x65\x6C\x6C\x6F World");
+
     println!("{\x41}", A = 92);
     println!("{ничоси}", ничоси = 92);
 }"#
         .trim(),
+        expect_file!["crates/ra_ide/test_data/highlight_strings.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_unsafe_highlighting() {
+    check_highlighting(
+        r#"
+unsafe fn unsafe_fn() {}
+
+struct HasUnsafeFn;
+
+impl HasUnsafeFn {
+    unsafe fn unsafe_method(&self) {}
+}
+
+fn main() {
+    let x = &5 as *const usize;
+    unsafe {
+        unsafe_fn();
+        HasUnsafeFn.unsafe_method();
+        let y = *(x);
+        let z = -x;
+    }
+}
+"#
+        .trim(),
+        expect_file!["crates/ra_ide/test_data/highlight_unsafe.html"],
+        false,
+    );
+}
+
+#[test]
+fn test_highlight_doctest() {
+    check_highlighting(
+        r#"
+/// ```
+/// let _ = "early doctests should not go boom";
+/// ```
+struct Foo {
+    bar: bool,
+}
+
+impl Foo {
+    pub const bar: bool = true;
+
+    /// Constructs a new `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # #![allow(unused_mut)]
+    /// let mut foo: Foo = Foo::new();
+    /// ```
+    pub const fn new() -> Foo {
+        Foo { bar: true }
+    }
+
+    /// `bar` method on `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use x::y;
+    ///
+    /// let foo = Foo::new();
+    ///
+    /// // calls bar on foo
+    /// assert!(foo.bar());
+    ///
+    /// let bar = foo.bar || Foo::bar;
+    ///
+    /// /* multi-line
+    ///        comment */
+    ///
+    /// let multi_line_string = "Foo
+    ///   bar
+    ///          ";
+    ///
+    /// ```
+    ///
+    /// ```rust,no_run
+    /// let foobar = Foo::new().bar();
+    /// ```
+    ///
+    /// ```sh
+    /// echo 1
+    /// ```
+    pub fn foo(&self) -> bool {
+        true
+    }
+}
+
+/// ```
+/// noop!(1);
+/// ```
+macro_rules! noop {
+    ($expr:expr) => {
+        $expr
+    }
+}
+"#
+        .trim(),
+        expect_file!["crates/ra_ide/test_data/highlight_doctest.html"],
+        false,
     );
+}
 
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlight_strings.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
+/// Highlights the code given by the `ra_fixture` argument, renders the
+/// result as HTML, and compares it with the HTML file given as `snapshot`.
+/// Note that the `snapshot` file is overwritten by the rendered HTML.
+fn check_highlighting(ra_fixture: &str, expect: ExpectFile, rainbow: bool) {
+    let (analysis, file_id) = single_file(ra_fixture);
+    let actual_html = &analysis.highlight_as_html(file_id, rainbow).unwrap();
+    expect.assert_eq(actual_html)
 }
diff --git a/crates/ra_ide/src/syntax_tree.rs b/crates/ra_ide/src/syntax_tree.rs
index a341684fd..f716a3861 100644
--- a/crates/ra_ide/src/syntax_tree.rs
+++ b/crates/ra_ide/src/syntax_tree.rs
@@ -104,7 +104,7 @@ fn syntax_tree_for_token(node: &SyntaxToken, text_range: TextRange) -> Option<St
 mod tests {
     use test_utils::assert_eq_text;
 
-    use crate::mock_analysis::{single_file, single_file_with_range};
+    use crate::mock_analysis::{analysis_and_range, single_file};
 
     #[test]
     fn test_syntax_tree_without_range() {
@@ -184,7 +184,7 @@ [email protected]
 
     #[test]
     fn test_syntax_tree_with_range() {
-        let (analysis, range) = single_file_with_range(r#"<|>fn foo() {}<|>"#.trim());
+        let (analysis, range) = analysis_and_range(r#"<|>fn foo() {}<|>"#.trim());
         let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
 
         assert_eq_text!(
@@ -206,7 +206,7 @@ [email protected]
             .trim()
         );
 
-        let (analysis, range) = single_file_with_range(
+        let (analysis, range) = analysis_and_range(
             r#"fn test() {
     <|>assert!("
     fn foo() {
@@ -242,7 +242,7 @@ [email protected]
 
     #[test]
     fn test_syntax_tree_inside_string() {
-        let (analysis, range) = single_file_with_range(
+        let (analysis, range) = analysis_and_range(
             r#"fn test() {
     assert!("
 <|>fn foo() {
@@ -276,7 +276,7 @@ [email protected]
         );
 
         // With a raw string
-        let (analysis, range) = single_file_with_range(
+        let (analysis, range) = analysis_and_range(
             r###"fn test() {
     assert!(r#"
 <|>fn foo() {
@@ -310,7 +310,7 @@ [email protected]
         );
 
         // With a raw string
-        let (analysis, range) = single_file_with_range(
+        let (analysis, range) = analysis_and_range(
             r###"fn test() {
     assert!(r<|>#"
 fn foo() {
diff --git a/crates/ra_ide/src/typing.rs b/crates/ra_ide/src/typing.rs
index 67e2c33a0..83776d2b6 100644
--- a/crates/ra_ide/src/typing.rs
+++ b/crates/ra_ide/src/typing.rs
@@ -17,11 +17,13 @@ mod on_enter;
 
 use ra_db::{FilePosition, SourceDatabase};
 use ra_fmt::leading_indent;
-use ra_ide_db::RootDatabase;
+use ra_ide_db::{source_change::SourceFileEdit, RootDatabase};
 use ra_syntax::{
     algo::find_node_at_offset,
     ast::{self, AstToken},
-    AstNode, SourceFile, TextRange, TextSize,
+    AstNode, SourceFile,
+    SyntaxKind::{FIELD_EXPR, METHOD_CALL_EXPR},
+    TextRange, TextSize,
 };
 
 use ra_text_edit::TextEdit;
@@ -47,8 +49,8 @@ pub(crate) fn on_char_typed(
     assert!(TRIGGER_CHARS.contains(char_typed));
     let file = &db.parse(position.file_id).tree();
     assert_eq!(file.syntax().text().char_at(position.offset), Some(char_typed));
-    let text_edit = on_char_typed_inner(file, position.offset, char_typed)?;
-    Some(SourceChange::source_file_edit_from(position.file_id, text_edit))
+    let edit = on_char_typed_inner(file, position.offset, char_typed)?;
+    Some(SourceFileEdit { file_id: position.file_id, edit }.into())
 }
 
 fn on_char_typed_inner(file: &SourceFile, offset: TextSize, char_typed: char) -> Option<TextEdit> {
@@ -98,9 +100,12 @@ fn on_dot_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
     };
     let current_indent_len = TextSize::of(current_indent);
 
+    let parent = whitespace.syntax().parent();
     // Make sure dot is a part of call chain
-    let field_expr = ast::FieldExpr::cast(whitespace.syntax().parent())?;
-    let prev_indent = leading_indent(field_expr.syntax())?;
+    if !matches!(parent.kind(), FIELD_EXPR | METHOD_CALL_EXPR) {
+        return None;
+    }
+    let prev_indent = leading_indent(&parent)?;
     let target_indent = format!("    {}", prev_indent);
     let target_indent_len = TextSize::of(&target_indent);
     if current_indent_len == target_indent_len {
@@ -143,11 +148,11 @@ mod tests {
         })
     }
 
-    fn type_char(char_typed: char, before: &str, after: &str) {
-        let actual = do_type_char(char_typed, before)
+    fn type_char(char_typed: char, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let actual = do_type_char(char_typed, ra_fixture_before)
             .unwrap_or_else(|| panic!("typing `{}` did nothing", char_typed));
 
-        assert_eq_text!(after, &actual);
+        assert_eq_text!(ra_fixture_after, &actual);
     }
 
     fn type_char_noop(char_typed: char, before: &str) {
@@ -249,6 +254,27 @@ fn foo() {
     }
 
     #[test]
+    fn indents_new_chain_call_with_let() {
+        type_char(
+            '.',
+            r#"
+fn main() {
+    let _ = foo
+    <|>
+    bar()
+}
+"#,
+            r#"
+fn main() {
+    let _ = foo
+        .
+    bar()
+}
+"#,
+        );
+    }
+
+    #[test]
     fn indents_continued_chain_call() {
         type_char(
             '.',
diff --git a/crates/ra_ide/src/typing/on_enter.rs b/crates/ra_ide/src/typing/on_enter.rs
index a40d8af9c..2faaa8ff0 100644
--- a/crates/ra_ide/src/typing/on_enter.rs
+++ b/crates/ra_ide/src/typing/on_enter.rs
@@ -75,23 +75,22 @@ fn node_indent(file: &SourceFile, token: &SyntaxToken) -> Option<SmolStr> {
 
 #[cfg(test)]
 mod tests {
-    use test_utils::{assert_eq_text, extract_offset};
+    use test_utils::assert_eq_text;
 
-    use crate::mock_analysis::single_file;
-
-    use super::*;
+    use crate::mock_analysis::analysis_and_position;
+    use stdx::trim_indent;
 
     fn apply_on_enter(before: &str) -> Option<String> {
-        let (offset, before) = extract_offset(before);
-        let (analysis, file_id) = single_file(&before);
-        let result = analysis.on_enter(FilePosition { offset, file_id }).unwrap()?;
+        let (analysis, position) = analysis_and_position(&before);
+        let result = analysis.on_enter(position).unwrap()?;
 
-        let mut actual = before.to_string();
+        let mut actual = analysis.file_text(position.file_id).unwrap().to_string();
         result.apply(&mut actual);
         Some(actual)
     }
 
     fn do_check(ra_fixture_before: &str, ra_fixture_after: &str) {
+        let ra_fixture_after = &trim_indent(ra_fixture_after);
         let actual = apply_on_enter(ra_fixture_before).unwrap();
         assert_eq_text!(ra_fixture_after, &actual);
     }
diff --git a/crates/ra_ide/test_data/highlight_doctest.html b/crates/ra_ide/test_data/highlight_doctest.html
new file mode 100644
index 000000000..1cc17d6d0
--- /dev/null
+++ b/crates/ra_ide/test_data/highlight_doctest.html
@@ -0,0 +1,102 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="comment documentation">/// ```</span>
+<span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="punctuation injected">_</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="string_literal injected">"early doctests should not go boom"</span><span class="punctuation injected">;</span><span class="punctuation injected">
+</span><span class="comment documentation">/// ```</span>
+<span class="keyword">struct</span> <span class="struct declaration">Foo</span> <span class="punctuation">{</span>
+    <span class="field declaration">bar</span><span class="punctuation">:</span> <span class="builtin_type">bool</span><span class="punctuation">,</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">impl</span> <span class="struct">Foo</span> <span class="punctuation">{</span>
+    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="constant declaration">bar</span><span class="punctuation">:</span> <span class="builtin_type">bool</span> <span class="punctuation">=</span> <span class="bool_literal">true</span><span class="punctuation">;</span>
+
+    <span class="comment documentation">/// Constructs a new `Foo`.</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// # Examples</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// ```</span>
+    <span class="comment documentation">/// #</span><span class="generic injected"> </span><span class="punctuation injected">#</span><span class="punctuation injected">!</span><span class="punctuation injected">[</span><span class="function attribute injected">allow</span><span class="punctuation injected">(</span><span class="attribute injected">unused_mut</span><span class="punctuation injected">)</span><span class="punctuation injected">]</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="keyword injected">mut</span><span class="generic injected"> </span><span class="variable declaration injected mutable">foo</span><span class="punctuation injected">:</span><span class="generic injected"> </span><span class="struct injected">Foo</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="struct injected">Foo</span><span class="punctuation injected">::</span><span class="function injected">new</span><span class="punctuation injected">(</span><span class="punctuation injected">)</span><span class="punctuation injected">;</span><span class="punctuation injected">
+</span>    <span class="comment documentation">/// ```</span>
+    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="keyword">fn</span> <span class="function declaration">new</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="struct">Foo</span> <span class="punctuation">{</span>
+        <span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">bar</span><span class="punctuation">:</span> <span class="bool_literal">true</span> <span class="punctuation">}</span>
+    <span class="punctuation">}</span>
+
+    <span class="comment documentation">/// `bar` method on `Foo`.</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// # Examples</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// ```</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">use</span><span class="generic injected"> </span><span class="module injected">x</span><span class="punctuation injected">::</span><span class="module injected">y</span><span class="punctuation injected">;</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="variable declaration injected">foo</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="struct injected">Foo</span><span class="punctuation injected">::</span><span class="function injected">new</span><span class="punctuation injected">(</span><span class="punctuation injected">)</span><span class="punctuation injected">;</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// </span><span class="comment injected">// calls bar on foo</span>
+    <span class="comment documentation">/// </span><span class="macro injected">assert!</span><span class="punctuation injected">(</span><span class="generic injected">foo</span><span class="punctuation injected">.</span><span class="generic injected">bar</span><span class="punctuation injected">(</span><span class="punctuation injected">)</span><span class="punctuation injected">)</span><span class="punctuation injected">;</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="variable declaration injected">bar</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="variable injected">foo</span><span class="punctuation injected">.</span><span class="field injected">bar</span><span class="generic injected"> </span><span class="punctuation injected">||</span><span class="generic injected"> </span><span class="struct injected">Foo</span><span class="punctuation injected">::</span><span class="constant injected">bar</span><span class="punctuation injected">;</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// </span><span class="comment injected">/* multi-line
+    </span><span class="comment documentation">/// </span><span class="comment injected">       comment */</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="variable declaration injected">multi_line_string</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="string_literal injected">"Foo
+    </span><span class="comment documentation">/// </span><span class="string_literal injected">  bar
+    </span><span class="comment documentation">/// </span><span class="string_literal injected">         "</span><span class="punctuation injected">;</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// ```</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// ```rust,no_run</span>
+    <span class="comment documentation">/// </span><span class="keyword injected">let</span><span class="generic injected"> </span><span class="variable declaration injected">foobar</span><span class="generic injected"> </span><span class="punctuation injected">=</span><span class="generic injected"> </span><span class="struct injected">Foo</span><span class="punctuation injected">::</span><span class="function injected">new</span><span class="punctuation injected">(</span><span class="punctuation injected">)</span><span class="punctuation injected">.</span><span class="function injected">bar</span><span class="punctuation injected">(</span><span class="punctuation injected">)</span><span class="punctuation injected">;</span><span class="punctuation injected">
+</span>    <span class="comment documentation">/// ```</span>
+    <span class="comment documentation">///</span>
+    <span class="comment documentation">/// ```sh</span>
+    <span class="comment documentation">/// echo 1</span>
+    <span class="comment documentation">/// ```</span>
+    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration">foo</span><span class="punctuation">(</span><span class="punctuation">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="builtin_type">bool</span> <span class="punctuation">{</span>
+        <span class="bool_literal">true</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="comment documentation">/// ```</span>
+<span class="comment documentation">/// </span><span class="macro injected">noop!</span><span class="punctuation injected">(</span><span class="numeric_literal injected">1</span><span class="punctuation injected">)</span><span class="punctuation injected">;</span><span class="punctuation injected">
+</span><span class="comment documentation">/// ```</span>
+<span class="macro">macro_rules!</span> <span class="macro declaration">noop</span> <span class="punctuation">{</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span>expr<span class="punctuation">:</span>expr<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
+        <span class="punctuation">$</span>expr
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/test_data/highlight_injection.html b/crates/ra_ide/test_data/highlight_injection.html
new file mode 100644
index 000000000..461cfc437
--- /dev/null
+++ b/crates/ra_ide/test_data/highlight_injection.html
@@ -0,0 +1,48 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="keyword">fn</span> <span class="function declaration">fixture</span><span class="punctuation">(</span><span class="value_param declaration">ra_fixture</span><span class="punctuation">:</span> <span class="punctuation">&</span><span class="builtin_type">str</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+
+<span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="function">fixture</span><span class="punctuation">(</span><span class="string_literal">r#"</span>
+        <span class="keyword">trait</span> <span class="trait declaration">Foo</span> <span class="punctuation">{</span>
+            <span class="keyword">fn</span> <span class="function declaration">foo</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+                <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"2 + 2 = {}"</span><span class="punctuation">,</span> <span class="numeric_literal">4</span><span class="punctuation">)</span><span class="punctuation">;</span>
+            <span class="punctuation">}</span>
+        <span class="punctuation">}</span><span class="string_literal">"#</span>
+    <span class="punctuation">)</span><span class="punctuation">;</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/test_data/highlight_strings.html b/crates/ra_ide/test_data/highlight_strings.html
new file mode 100644
index 000000000..9f98e73e7
--- /dev/null
+++ b/crates/ra_ide/test_data/highlight_strings.html
@@ -0,0 +1,96 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="macro">macro_rules!</span> <span class="macro declaration">println</span> <span class="punctuation">{</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>arg<span class="punctuation">:</span>tt<span class="punctuation">)</span>*<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">(</span><span class="punctuation">{</span>
+        <span class="punctuation">$</span><span class="keyword">crate</span><span class="punctuation">:</span><span class="punctuation">:</span>io<span class="punctuation">:</span><span class="punctuation">:</span>_print<span class="punctuation">(</span><span class="punctuation">$</span><span class="keyword">crate</span><span class="punctuation">:</span><span class="punctuation">:</span>format_args_nl<span class="punctuation">!</span><span class="punctuation">(</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>arg<span class="punctuation">)</span>*<span class="punctuation">)</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="punctuation">}</span><span class="punctuation">)</span>
+<span class="punctuation">}</span>
+#[rustc_builtin_macro]
+<span class="macro">macro_rules!</span> <span class="macro declaration">format_args_nl</span> <span class="punctuation">{</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span>fmt<span class="punctuation">:</span>expr<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">{</span> <span class="comment">/* compiler built-in */</span> <span class="punctuation">}</span><span class="punctuation">}</span><span class="punctuation">;</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span>fmt<span class="punctuation">:</span>expr<span class="punctuation">,</span> <span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>args<span class="punctuation">:</span>tt<span class="punctuation">)</span>*<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">{</span> <span class="comment">/* compiler built-in */</span> <span class="punctuation">}</span><span class="punctuation">}</span><span class="punctuation">;</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="comment">// from https://doc.rust-lang.org/std/fmt/index.html</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello"</span><span class="punctuation">)</span><span class="punctuation">;</span>                 <span class="comment">// =&gt; "Hello"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello, </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"world"</span><span class="punctuation">)</span><span class="punctuation">;</span>   <span class="comment">// =&gt; "Hello, world!"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"The number is </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">1</span><span class="punctuation">)</span><span class="punctuation">;</span>   <span class="comment">// =&gt; "The number is 1"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">?</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="punctuation">(</span><span class="numeric_literal">3</span><span class="punctuation">,</span> <span class="numeric_literal">4</span><span class="punctuation">)</span><span class="punctuation">)</span><span class="punctuation">;</span>          <span class="comment">// =&gt; "(3, 4)"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">value</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> value<span class="punctuation">=</span><span class="numeric_literal">4</span><span class="punctuation">)</span><span class="punctuation">;</span>      <span class="comment">// =&gt; "4"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">1</span><span class="punctuation">,</span> <span class="numeric_literal">2</span><span class="punctuation">)</span><span class="punctuation">;</span>           <span class="comment">// =&gt; "1 2"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">4</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">42</span><span class="punctuation">)</span><span class="punctuation">;</span>             <span class="comment">// =&gt; "0042" with leading zerosV</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">1</span><span class="punctuation">,</span> <span class="numeric_literal">2</span><span class="punctuation">)</span><span class="punctuation">;</span>   <span class="comment">// =&gt; "2 1 1 2"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">argument</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> argument <span class="punctuation">=</span> <span class="string_literal">"test"</span><span class="punctuation">)</span><span class="punctuation">;</span>   <span class="comment">// =&gt; "test"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">1</span><span class="punctuation">,</span> name <span class="punctuation">=</span> <span class="numeric_literal">2</span><span class="punctuation">)</span><span class="punctuation">;</span>          <span class="comment">// =&gt; "2 1"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">a</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">c</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">b</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> a<span class="punctuation">=</span><span class="string_literal">"a"</span><span class="punctuation">,</span> b<span class="punctuation">=</span><span class="char_literal">'b'</span><span class="punctuation">,</span> c<span class="punctuation">=</span><span class="numeric_literal">3</span><span class="punctuation">)</span><span class="punctuation">;</span>  <span class="comment">// =&gt; "a 3 b"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"{{</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">}}"</span><span class="punctuation">,</span> <span class="numeric_literal">2</span><span class="punctuation">)</span><span class="punctuation">;</span>                       <span class="comment">// =&gt; "{2}"</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">1</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="variable">width</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> width <span class="punctuation">=</span> <span class="numeric_literal">5</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">&lt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">-</span><span class="format_specifier">&lt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">^</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">&gt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">+</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="numeric_literal">27</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="punctuation">-</span><span class="numeric_literal">5</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="numeric_literal">0</span><span class="numeric_literal">10</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="numeric_literal">27</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">0</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="numeric_literal">1</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span>    <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="numeric_literal">2</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span>   <span class="string_literal">"x"</span><span class="punctuation">,</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal"> is </span><span class="format_specifier">{</span><span class="variable">number</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="variable">prec</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> <span class="string_literal">"x"</span><span class="punctuation">,</span> prec <span class="punctuation">=</span> <span class="numeric_literal">5</span><span class="punctuation">,</span> number <span class="punctuation">=</span> <span class="numeric_literal">0.01</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 fractional digits"</span><span class="punctuation">,</span> <span class="string_literal">"Hello"</span><span class="punctuation">,</span> <span class="numeric_literal">3</span><span class="punctuation">,</span> name<span class="punctuation">=</span><span class="numeric_literal">1234.56</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 characters"</span><span class="punctuation">,</span> <span class="string_literal">"Hello"</span><span class="punctuation">,</span> <span class="numeric_literal">3</span><span class="punctuation">,</span> name<span class="punctuation">=</span><span class="string_literal">"1234.56"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">, `</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">:</span><span class="format_specifier">&gt;</span><span class="numeric_literal">8</span><span class="format_specifier">.</span><span class="format_specifier">*</span><span class="format_specifier">}</span><span class="string_literal">` has 3 right-aligned characters"</span><span class="punctuation">,</span> <span class="string_literal">"Hello"</span><span class="punctuation">,</span> <span class="numeric_literal">3</span><span class="punctuation">,</span> name<span class="punctuation">=</span><span class="string_literal">"1234.56"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello {{}}"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"{{ Hello"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">r"Hello, </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">!"</span><span class="punctuation">,</span> <span class="string_literal">"world"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="comment">// escape sequences</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello</span><span class="escape_sequence">\n</span><span class="string_literal">World"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="escape_sequence">\u{48}</span><span class="escape_sequence">\x65</span><span class="escape_sequence">\x6C</span><span class="escape_sequence">\x6C</span><span class="escape_sequence">\x6F</span><span class="string_literal"> World"</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="escape_sequence">\x41</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> A <span class="punctuation">=</span> <span class="numeric_literal">92</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">ничоси</span><span class="format_specifier">}</span><span class="string_literal">"</span><span class="punctuation">,</span> ничоси <span class="punctuation">=</span> <span class="numeric_literal">92</span><span class="punctuation">)</span><span class="punctuation">;</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/test_data/highlight_unsafe.html b/crates/ra_ide/test_data/highlight_unsafe.html
new file mode 100644
index 000000000..88ac91f9a
--- /dev/null
+++ b/crates/ra_ide/test_data/highlight_unsafe.html
@@ -0,0 +1,54 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_fn</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+
+<span class="keyword">struct</span> <span class="struct declaration">HasUnsafeFn</span><span class="punctuation">;</span>
+
+<span class="keyword">impl</span> <span class="struct">HasUnsafeFn</span> <span class="punctuation">{</span>
+    <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_method</span><span class="punctuation">(</span><span class="punctuation">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">{</span><span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="punctuation">=</span> <span class="punctuation">&</span><span class="numeric_literal">5</span> <span class="keyword">as</span> *<span class="keyword">const</span> <span class="builtin_type">usize</span><span class="punctuation">;</span>
+    <span class="keyword unsafe">unsafe</span> <span class="punctuation">{</span>
+        <span class="function unsafe">unsafe_fn</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+        <span class="struct">HasUnsafeFn</span><span class="punctuation">.</span><span class="function unsafe">unsafe_method</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="variable declaration">y</span> <span class="punctuation">=</span> <span class="operator unsafe">*</span><span class="punctuation">(</span><span class="variable">x</span><span class="punctuation">)</span><span class="punctuation">;</span>
+        <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="punctuation">=</span> <span class="punctuation">-</span><span class="variable">x</span><span class="punctuation">;</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/test_data/highlighting.html b/crates/ra_ide/test_data/highlighting.html
new file mode 100644
index 000000000..767e82f9d
--- /dev/null
+++ b/crates/ra_ide/test_data/highlighting.html
@@ -0,0 +1,128 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="punctuation">#</span><span class="punctuation">[</span><span class="function attribute">derive</span><span class="punctuation">(</span><span class="attribute">Clone</span><span class="punctuation">,</span><span class="attribute"> Debug</span><span class="punctuation">)</span><span class="punctuation">]</span>
+<span class="keyword">struct</span> <span class="struct declaration">Foo</span> <span class="punctuation">{</span>
+    <span class="keyword">pub</span> <span class="field declaration">x</span><span class="punctuation">:</span> <span class="builtin_type">i32</span><span class="punctuation">,</span>
+    <span class="keyword">pub</span> <span class="field declaration">y</span><span class="punctuation">:</span> <span class="builtin_type">i32</span><span class="punctuation">,</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">trait</span> <span class="trait declaration">Bar</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="punctuation">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="builtin_type">i32</span><span class="punctuation">;</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">impl</span> <span class="trait">Bar</span> <span class="keyword">for</span> <span class="struct">Foo</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="punctuation">&</span><span class="self_keyword">self</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="builtin_type">i32</span> <span class="punctuation">{</span>
+        <span class="self_keyword">self</span><span class="punctuation">.</span><span class="field">x</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">impl</span> <span class="struct">Foo</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">baz</span><span class="punctuation">(</span><span class="keyword">mut</span> <span class="self_keyword mutable">self</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="builtin_type">i32</span> <span class="punctuation">{</span>
+        <span class="self_keyword">self</span><span class="punctuation">.</span><span class="field">x</span>
+    <span class="punctuation">}</span>
+
+    <span class="keyword">fn</span> <span class="function declaration">qux</span><span class="punctuation">(</span><span class="punctuation">&</span><span class="keyword">mut</span> <span class="self_keyword mutable">self</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+        <span class="self_keyword mutable">self</span><span class="punctuation">.</span><span class="field">x</span> <span class="punctuation">=</span> <span class="numeric_literal">0</span><span class="punctuation">;</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable">STATIC_MUT</span><span class="punctuation">:</span> <span class="builtin_type">i32</span> <span class="punctuation">=</span> <span class="numeric_literal">0</span><span class="punctuation">;</span>
+
+<span class="keyword">fn</span> <span class="function declaration">foo</span><span class="punctuation">&lt;</span><span class="lifetime declaration">'a</span><span class="punctuation">,</span> <span class="type_param declaration">T</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="type_param">T</span> <span class="punctuation">{</span>
+    <span class="function">foo</span><span class="punctuation">::</span><span class="punctuation">&lt;</span><span class="lifetime">'a</span><span class="punctuation">,</span> <span class="builtin_type">i32</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="punctuation">)</span>
+<span class="punctuation">}</span>
+
+<span class="macro">macro_rules!</span> <span class="macro declaration">def_fn</span> <span class="punctuation">{</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>tt<span class="punctuation">:</span>tt<span class="punctuation">)</span>*<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span><span class="punctuation">$</span><span class="punctuation">(</span><span class="punctuation">$</span>tt<span class="punctuation">)</span>*<span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="macro">def_fn!</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">-</span><span class="punctuation">&gt;</span> <span class="builtin_type">u32</span> <span class="punctuation">{</span>
+        <span class="numeric_literal">100</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="macro">macro_rules!</span> <span class="macro declaration">noop</span> <span class="punctuation">{</span>
+    <span class="punctuation">(</span><span class="punctuation">$</span>expr<span class="punctuation">:</span>expr<span class="punctuation">)</span> <span class="punctuation">=</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
+        <span class="punctuation">$</span>expr
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span>
+
+<span class="comment">// comment</span>
+<span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="macro">println!</span><span class="punctuation">(</span><span class="string_literal">"Hello, {}!"</span><span class="punctuation">,</span> <span class="numeric_literal">92</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">vec</span> <span class="punctuation">=</span> <span class="unresolved_reference">Vec</span><span class="punctuation">::</span><span class="unresolved_reference">new</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="keyword control">if</span> <span class="bool_literal">true</span> <span class="punctuation">{</span>
+        <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="punctuation">=</span> <span class="numeric_literal">92</span><span class="punctuation">;</span>
+        <span class="variable mutable">vec</span><span class="punctuation">.</span><span class="unresolved_reference">push</span><span class="punctuation">(</span><span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">x</span><span class="punctuation">,</span> <span class="field">y</span><span class="punctuation">:</span> <span class="numeric_literal">1</span> <span class="punctuation">}</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="punctuation">}</span>
+    <span class="keyword unsafe">unsafe</span> <span class="punctuation">{</span>
+        <span class="variable mutable">vec</span><span class="punctuation">.</span><span class="unresolved_reference">set_len</span><span class="punctuation">(</span><span class="numeric_literal">0</span><span class="punctuation">)</span><span class="punctuation">;</span>
+        <span class="static mutable">STATIC_MUT</span> <span class="punctuation">=</span> <span class="numeric_literal">1</span><span class="punctuation">;</span>
+    <span class="punctuation">}</span>
+
+    <span class="keyword control">for</span> <span class="variable declaration">e</span> <span class="keyword control">in</span> <span class="variable mutable">vec</span> <span class="punctuation">{</span>
+        <span class="comment">// Do nothing</span>
+    <span class="punctuation">}</span>
+
+    <span class="macro">noop!</span><span class="punctuation">(</span><span class="macro">noop</span><span class="macro">!</span><span class="punctuation">(</span><span class="numeric_literal">1</span><span class="punctuation">)</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> <span class="punctuation">=</span> <span class="numeric_literal">42</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration mutable">y</span> <span class="punctuation">=</span> <span class="punctuation">&</span><span class="keyword">mut</span> <span class="variable mutable">x</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="punctuation">=</span> <span class="punctuation">&</span><span class="variable mutable">y</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">x</span><span class="punctuation">:</span> <span class="variable declaration">z</span><span class="punctuation">,</span> <span class="field">y</span> <span class="punctuation">}</span> <span class="punctuation">=</span> <span class="struct">Foo</span> <span class="punctuation">{</span> <span class="field">x</span><span class="punctuation">:</span> <span class="variable">z</span><span class="punctuation">,</span> <span class="field">y</span> <span class="punctuation">}</span><span class="punctuation">;</span>
+
+    <span class="variable">y</span><span class="punctuation">;</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">enum</span> <span class="enum declaration">Option</span><span class="punctuation">&lt;</span><span class="type_param declaration">T</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
+    <span class="enum_variant declaration">Some</span><span class="punctuation">(</span><span class="type_param">T</span><span class="punctuation">)</span><span class="punctuation">,</span>
+    <span class="enum_variant declaration">None</span><span class="punctuation">,</span>
+<span class="punctuation">}</span>
+<span class="keyword">use</span> <span class="enum">Option</span><span class="punctuation">::</span>*<span class="punctuation">;</span>
+
+<span class="keyword">impl</span><span class="punctuation">&lt;</span><span class="type_param declaration">T</span><span class="punctuation">&gt;</span> <span class="enum">Option</span><span class="punctuation">&lt;</span><span class="type_param">T</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
+    <span class="keyword">fn</span> <span class="function declaration">and</span><span class="punctuation">&lt;</span><span class="type_param declaration">U</span><span class="punctuation">&gt;</span><span class="punctuation">(</span><span class="self_keyword">self</span><span class="punctuation">,</span> <span class="value_param declaration">other</span><span class="punctuation">:</span> <span class="enum">Option</span><span class="punctuation">&lt;</span><span class="type_param">U</span><span class="punctuation">&gt;</span><span class="punctuation">)</span> <span class="punctuation">-&gt;</span> <span class="enum">Option</span><span class="punctuation">&lt;</span><span class="punctuation">(</span><span class="type_param">T</span><span class="punctuation">,</span> <span class="type_param">U</span><span class="punctuation">)</span><span class="punctuation">&gt;</span> <span class="punctuation">{</span>
+        <span class="keyword control">match</span> <span class="value_param">other</span> <span class="punctuation">{</span>
+            <span class="enum_variant">None</span> <span class="punctuation">=&gt;</span> <span class="macro">unimplemented!</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">,</span>
+            <span class="variable declaration">Nope</span> <span class="punctuation">=&gt;</span> <span class="variable">Nope</span><span class="punctuation">,</span>
+        <span class="punctuation">}</span>
+    <span class="punctuation">}</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/test_data/rainbow_highlighting.html b/crates/ra_ide/test_data/rainbow_highlighting.html
new file mode 100644
index 000000000..2fed04a44
--- /dev/null
+++ b/crates/ra_ide/test_data/rainbow_highlighting.html
@@ -0,0 +1,49 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.documentation      { color: #629755; }
+.injected           { opacity: 0.65 ; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.value_param        { color: #DCDCCC; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+.escape_sequence    { color: #94BFF3; }
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+
+.unresolved_reference { color: #FC5555; text-decoration: wavy underline; }
+</style>
+<pre><code><span class="keyword">fn</span> <span class="function declaration">main</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span> <span class="punctuation">=</span> <span class="string_literal">"hello"</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="2705725358298919760" style="color: hsl(17,51%,74%);">x</span> <span class="punctuation">=</span> <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span><span class="punctuation">.</span><span class="unresolved_reference">to_string</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="3365759661443752373" style="color: hsl(127,76%,66%);">y</span> <span class="punctuation">=</span> <span class="variable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span><span class="punctuation">.</span><span class="unresolved_reference">to_string</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span> <span class="punctuation">=</span> <span class="string_literal">"other color please!"</span><span class="punctuation">;</span>
+    <span class="keyword">let</span> <span class="variable declaration" data-binding-hash="6717528807933952652" style="color: hsl(85,49%,84%);">y</span> <span class="punctuation">=</span> <span class="variable" data-binding-hash="794745962933817518" style="color: hsl(19,74%,76%);">x</span><span class="punctuation">.</span><span class="unresolved_reference">to_string</span><span class="punctuation">(</span><span class="punctuation">)</span><span class="punctuation">;</span>
+<span class="punctuation">}</span>
+
+<span class="keyword">fn</span> <span class="function declaration">bar</span><span class="punctuation">(</span><span class="punctuation">)</span> <span class="punctuation">{</span>
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable" data-binding-hash="8121853618659664005" style="color: hsl(261,57%,61%);">hello</span> <span class="punctuation">=</span> <span class="string_literal">"hello"</span><span class="punctuation">;</span>
+<span class="punctuation">}</span></code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide_db/Cargo.toml b/crates/ra_ide_db/Cargo.toml
index c3921bd40..bcddad60c 100644
--- a/crates/ra_ide_db/Cargo.toml
+++ b/crates/ra_ide_db/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_ide_db"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_ide_db/src/change.rs b/crates/ra_ide_db/src/change.rs
index 8446ef88e..a1bb3043b 100644
--- a/crates/ra_ide_db/src/change.rs
+++ b/crates/ra_ide_db/src/change.rs
@@ -5,45 +5,29 @@ use std::{fmt, sync::Arc, time};
 
 use ra_db::{
     salsa::{Database, Durability, SweepStrategy},
-    CrateGraph, FileId, RelativePathBuf, SourceDatabase, SourceDatabaseExt, SourceRoot,
-    SourceRootId,
+    CrateGraph, FileId, SourceDatabase, SourceDatabaseExt, SourceRoot, SourceRootId,
 };
 use ra_prof::{memory_usage, profile, Bytes};
-use ra_syntax::SourceFile;
-#[cfg(not(feature = "wasm"))]
-use rayon::prelude::*;
-use rustc_hash::FxHashMap;
-
-use crate::{
-    symbol_index::{SymbolIndex, SymbolsDatabase},
-    DebugData, RootDatabase,
-};
+use rustc_hash::FxHashSet;
+
+use crate::{symbol_index::SymbolsDatabase, RootDatabase};
 
 #[derive(Default)]
 pub struct AnalysisChange {
-    new_roots: Vec<(SourceRootId, bool)>,
-    roots_changed: FxHashMap<SourceRootId, RootChange>,
-    files_changed: Vec<(FileId, Arc<String>)>,
-    libraries_added: Vec<LibraryData>,
+    roots: Option<Vec<SourceRoot>>,
+    files_changed: Vec<(FileId, Option<Arc<String>>)>,
     crate_graph: Option<CrateGraph>,
-    debug_data: DebugData,
 }
 
 impl fmt::Debug for AnalysisChange {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         let mut d = fmt.debug_struct("AnalysisChange");
-        if !self.new_roots.is_empty() {
-            d.field("new_roots", &self.new_roots);
-        }
-        if !self.roots_changed.is_empty() {
-            d.field("roots_changed", &self.roots_changed);
+        if let Some(roots) = &self.roots {
+            d.field("roots", roots);
         }
         if !self.files_changed.is_empty() {
             d.field("files_changed", &self.files_changed.len());
         }
-        if !self.libraries_added.is_empty() {
-            d.field("libraries_added", &self.libraries_added.len());
-        }
         if self.crate_graph.is_some() {
             d.field("crate_graph", &self.crate_graph);
         }
@@ -56,54 +40,30 @@ impl AnalysisChange {
         AnalysisChange::default()
     }
 
-    pub fn add_root(&mut self, root_id: SourceRootId, is_local: bool) {
-        self.new_roots.push((root_id, is_local));
+    pub fn set_roots(&mut self, roots: Vec<SourceRoot>) {
+        self.roots = Some(roots);
     }
 
-    pub fn add_file(
-        &mut self,
-        root_id: SourceRootId,
-        file_id: FileId,
-        path: RelativePathBuf,
-        text: Arc<String>,
-    ) {
-        let file = AddFile { file_id, path, text };
-        self.roots_changed.entry(root_id).or_default().added.push(file);
-    }
-
-    pub fn change_file(&mut self, file_id: FileId, new_text: Arc<String>) {
+    pub fn change_file(&mut self, file_id: FileId, new_text: Option<Arc<String>>) {
         self.files_changed.push((file_id, new_text))
     }
 
-    pub fn remove_file(&mut self, root_id: SourceRootId, file_id: FileId, path: RelativePathBuf) {
-        let file = RemoveFile { file_id, path };
-        self.roots_changed.entry(root_id).or_default().removed.push(file);
-    }
-
-    pub fn add_library(&mut self, data: LibraryData) {
-        self.libraries_added.push(data)
-    }
-
     pub fn set_crate_graph(&mut self, graph: CrateGraph) {
         self.crate_graph = Some(graph);
     }
-
-    pub fn set_debug_root_path(&mut self, source_root_id: SourceRootId, path: String) {
-        self.debug_data.root_paths.insert(source_root_id, path);
-    }
 }
 
 #[derive(Debug)]
 struct AddFile {
     file_id: FileId,
-    path: RelativePathBuf,
+    path: String,
     text: Arc<String>,
 }
 
 #[derive(Debug)]
 struct RemoveFile {
     file_id: FileId,
-    path: RelativePathBuf,
+    path: String,
 }
 
 #[derive(Default)]
@@ -121,47 +81,6 @@ impl fmt::Debug for RootChange {
     }
 }
 
-pub struct LibraryData {
-    root_id: SourceRootId,
-    root_change: RootChange,
-    symbol_index: SymbolIndex,
-}
-
-impl fmt::Debug for LibraryData {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("LibraryData")
-            .field("root_id", &self.root_id)
-            .field("root_change", &self.root_change)
-            .field("n_symbols", &self.symbol_index.len())
-            .finish()
-    }
-}
-
-impl LibraryData {
-    pub fn prepare(
-        root_id: SourceRootId,
-        files: Vec<(FileId, RelativePathBuf, Arc<String>)>,
-    ) -> LibraryData {
-        let _p = profile("LibraryData::prepare");
-
-        #[cfg(not(feature = "wasm"))]
-        let iter = files.par_iter();
-        #[cfg(feature = "wasm")]
-        let iter = files.iter();
-
-        let symbol_index = SymbolIndex::for_files(iter.map(|(file_id, _, text)| {
-            let parse = SourceFile::parse(text);
-            (*file_id, parse)
-        }));
-        let mut root_change = RootChange::default();
-        root_change.added = files
-            .into_iter()
-            .map(|(file_id, path, text)| AddFile { file_id, path, text })
-            .collect();
-        LibraryData { root_id, root_change, symbol_index }
-    }
-}
-
 const GC_COOLDOWN: time::Duration = time::Duration::from_millis(100);
 
 impl RootDatabase {
@@ -174,72 +93,37 @@ impl RootDatabase {
         let _p = profile("RootDatabase::apply_change");
         self.request_cancellation();
         log::info!("apply_change {:?}", change);
-        if !change.new_roots.is_empty() {
-            let mut local_roots = Vec::clone(&self.local_roots());
-            for (root_id, is_local) in change.new_roots {
-                let root =
-                    if is_local { SourceRoot::new_local() } else { SourceRoot::new_library() };
+        if let Some(roots) = change.roots {
+            let mut local_roots = FxHashSet::default();
+            let mut library_roots = FxHashSet::default();
+            for (idx, root) in roots.into_iter().enumerate() {
+                let root_id = SourceRootId(idx as u32);
                 let durability = durability(&root);
-                self.set_source_root_with_durability(root_id, Arc::new(root), durability);
-                if is_local {
-                    local_roots.push(root_id);
+                if root.is_library {
+                    library_roots.insert(root_id);
+                } else {
+                    local_roots.insert(root_id);
                 }
+                for file_id in root.iter() {
+                    self.set_file_source_root_with_durability(file_id, root_id, durability);
+                }
+                self.set_source_root_with_durability(root_id, Arc::new(root), durability);
             }
             self.set_local_roots_with_durability(Arc::new(local_roots), Durability::HIGH);
+            self.set_library_roots_with_durability(Arc::new(library_roots), Durability::HIGH);
         }
 
-        for (root_id, root_change) in change.roots_changed {
-            self.apply_root_change(root_id, root_change);
-        }
         for (file_id, text) in change.files_changed {
             let source_root_id = self.file_source_root(file_id);
             let source_root = self.source_root(source_root_id);
             let durability = durability(&source_root);
+            // XXX: can't actually remove the file, just reset the text
+            let text = text.unwrap_or_default();
             self.set_file_text_with_durability(file_id, text, durability)
         }
-        if !change.libraries_added.is_empty() {
-            let mut libraries = Vec::clone(&self.library_roots());
-            for library in change.libraries_added {
-                libraries.push(library.root_id);
-                self.set_source_root_with_durability(
-                    library.root_id,
-                    Arc::new(SourceRoot::new_library()),
-                    Durability::HIGH,
-                );
-                self.set_library_symbols_with_durability(
-                    library.root_id,
-                    Arc::new(library.symbol_index),
-                    Durability::HIGH,
-                );
-                self.apply_root_change(library.root_id, library.root_change);
-            }
-            self.set_library_roots_with_durability(Arc::new(libraries), Durability::HIGH);
-        }
         if let Some(crate_graph) = change.crate_graph {
             self.set_crate_graph_with_durability(Arc::new(crate_graph), Durability::HIGH)
         }
-
-        Arc::make_mut(&mut self.debug_data).merge(change.debug_data)
-    }
-
-    fn apply_root_change(&mut self, root_id: SourceRootId, root_change: RootChange) {
-        let mut source_root = SourceRoot::clone(&self.source_root(root_id));
-        let durability = durability(&source_root);
-        for add_file in root_change.added {
-            self.set_file_text_with_durability(add_file.file_id, add_file.text, durability);
-            self.set_file_relative_path_with_durability(
-                add_file.file_id,
-                add_file.path.clone(),
-                durability,
-            );
-            self.set_file_source_root_with_durability(add_file.file_id, root_id, durability);
-            source_root.insert_file(add_file.path, add_file.file_id);
-        }
-        for remove_file in root_change.removed {
-            self.set_file_text_with_durability(remove_file.file_id, Default::default(), durability);
-            source_root.remove_file(&remove_file.path);
-        }
-        self.set_source_root_with_durability(root_id, Arc::new(source_root), durability);
     }
 
     pub fn maybe_collect_garbage(&mut self) {
@@ -262,37 +146,46 @@ impl RootDatabase {
 
         let sweep = SweepStrategy::default().discard_values().sweep_all_revisions();
 
-        self.query(ra_db::ParseQuery).sweep(sweep);
-        self.query(hir::db::ParseMacroQuery).sweep(sweep);
+        ra_db::ParseQuery.in_db(self).sweep(sweep);
+        hir::db::ParseMacroQuery.in_db(self).sweep(sweep);
 
         // Macros do take significant space, but less then the syntax trees
         // self.query(hir::db::MacroDefQuery).sweep(sweep);
         // self.query(hir::db::MacroArgQuery).sweep(sweep);
         // self.query(hir::db::MacroExpandQuery).sweep(sweep);
 
-        self.query(hir::db::AstIdMapQuery).sweep(sweep);
+        hir::db::AstIdMapQuery.in_db(self).sweep(sweep);
 
-        self.query(hir::db::BodyWithSourceMapQuery).sweep(sweep);
+        hir::db::BodyWithSourceMapQuery.in_db(self).sweep(sweep);
 
-        self.query(hir::db::ExprScopesQuery).sweep(sweep);
-        self.query(hir::db::InferQueryQuery).sweep(sweep);
-        self.query(hir::db::BodyQuery).sweep(sweep);
+        hir::db::ExprScopesQuery.in_db(self).sweep(sweep);
+        hir::db::InferQueryQuery.in_db(self).sweep(sweep);
+        hir::db::BodyQuery.in_db(self).sweep(sweep);
     }
 
+    // Feature: Memory Usage
+    //
+    // Clears rust-analyzer's internal database and prints memory usage statistics.
+    //
+    // |===
+    // | Editor  | Action Name
+    //
+    // | VS Code | **Rust Analyzer: Memory Usage (Clears Database)**
+    // |===
     pub fn per_query_memory_usage(&mut self) -> Vec<(String, Bytes)> {
         let mut acc: Vec<(String, Bytes)> = vec![];
         let sweep = SweepStrategy::default().discard_values().sweep_all_revisions();
         macro_rules! sweep_each_query {
             ($($q:path)*) => {$(
                 let before = memory_usage().allocated;
-                self.query($q).sweep(sweep);
+                $q.in_db(self).sweep(sweep);
                 let after = memory_usage().allocated;
                 let q: $q = Default::default();
                 let name = format!("{:?}", q);
                 acc.push((name, before - after));
 
                 let before = memory_usage().allocated;
-                self.query($q).sweep(sweep.discard_everything());
+                $q.in_db(self).sweep(sweep.discard_everything());
                 let after = memory_usage().allocated;
                 let q: $q = Default::default();
                 let name = format!("{:?} (deps)", q);
@@ -306,15 +199,13 @@ impl RootDatabase {
 
             // AstDatabase
             hir::db::AstIdMapQuery
-            hir::db::InternMacroQuery
             hir::db::MacroArgQuery
             hir::db::MacroDefQuery
             hir::db::ParseMacroQuery
             hir::db::MacroExpandQuery
-            hir::db::InternEagerExpansionQuery
 
             // DefDatabase
-            hir::db::RawItemsQuery
+            hir::db::ItemTreeQuery
             hir::db::CrateDefMapQueryQuery
             hir::db::StructDataQuery
             hir::db::UnionDataQuery
@@ -334,17 +225,7 @@ impl RootDatabase {
             hir::db::CrateLangItemsQuery
             hir::db::LangItemQuery
             hir::db::DocumentationQuery
-
-            // InternDatabase
-            hir::db::InternFunctionQuery
-            hir::db::InternStructQuery
-            hir::db::InternUnionQuery
-            hir::db::InternEnumQuery
-            hir::db::InternConstQuery
-            hir::db::InternStaticQuery
-            hir::db::InternTraitQuery
-            hir::db::InternTypeAliasQuery
-            hir::db::InternImplQuery
+            hir::db::ImportMapQuery
 
             // HirDatabase
             hir::db::InferQueryQuery
@@ -357,18 +238,16 @@ impl RootDatabase {
             hir::db::GenericPredicatesForParamQuery
             hir::db::GenericPredicatesQuery
             hir::db::GenericDefaultsQuery
-            hir::db::ImplsInCrateQuery
-            hir::db::ImplsForTraitQuery
-            hir::db::InternTypeCtorQuery
-            hir::db::InternTypeParamIdQuery
-            hir::db::InternChalkImplQuery
-            hir::db::InternAssocTyValueQuery
+            hir::db::InherentImplsInCrateQuery
+            hir::db::TraitImplsInCrateQuery
+            hir::db::TraitImplsInDepsQuery
             hir::db::AssociatedTyDataQuery
             hir::db::TraitDatumQuery
             hir::db::StructDatumQuery
             hir::db::ImplDatumQuery
             hir::db::AssociatedTyValueQuery
             hir::db::TraitSolveQuery
+            hir::db::ReturnTypeImplTraitsQuery
 
             // SymbolsDatabase
             crate::symbol_index::FileSymbolsQuery
@@ -376,6 +255,33 @@ impl RootDatabase {
             // LineIndexDatabase
             crate::LineIndexQuery
         ];
+
+        // To collect interned data, we need to bump the revision counter by performing a synthetic
+        // write.
+        // We do this after collecting the non-interned queries to correctly attribute memory used
+        // by interned data.
+        self.salsa_runtime_mut().synthetic_write(Durability::HIGH);
+
+        sweep_each_query![
+            // AstDatabase
+            hir::db::InternMacroQuery
+            hir::db::InternEagerExpansionQuery
+
+            // InternDatabase
+            hir::db::InternFunctionQuery
+            hir::db::InternStructQuery
+            hir::db::InternUnionQuery
+            hir::db::InternEnumQuery
+            hir::db::InternConstQuery
+            hir::db::InternStaticQuery
+            hir::db::InternTraitQuery
+            hir::db::InternTypeAliasQuery
+            hir::db::InternImplQuery
+
+            // HirDatabase
+            hir::db::InternTypeParamIdQuery
+        ];
+
         acc.sort_by_key(|it| std::cmp::Reverse(it.1));
         acc
     }
diff --git a/crates/ra_ide_db/src/defs.rs b/crates/ra_ide_db/src/defs.rs
index 8b06cbfc5..bcaabca92 100644
--- a/crates/ra_ide_db/src/defs.rs
+++ b/crates/ra_ide_db/src/defs.rs
@@ -18,7 +18,7 @@ use ra_syntax::{
 use crate::RootDatabase;
 
 // FIXME: a more precise name would probably be `Symbol`?
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum Definition {
     Macro(MacroDef),
     Field(Field),
@@ -78,10 +78,15 @@ impl Definition {
     }
 }
 
+#[derive(Debug)]
 pub enum NameClass {
     Definition(Definition),
     /// `None` in `if let None = Some(82) {}`
     ConstReference(Definition),
+    FieldShorthand {
+        local: Local,
+        field: Definition,
+    },
 }
 
 impl NameClass {
@@ -89,12 +94,14 @@ impl NameClass {
         match self {
             NameClass::Definition(it) => Some(it),
             NameClass::ConstReference(_) => None,
+            NameClass::FieldShorthand { local, field: _ } => Some(Definition::Local(local)),
         }
     }
 
     pub fn definition(self) -> Definition {
         match self {
             NameClass::Definition(it) | NameClass::ConstReference(it) => it,
+            NameClass::FieldShorthand { local: _, field } => field,
         }
     }
 }
@@ -102,18 +109,14 @@ impl NameClass {
 pub fn classify_name(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<NameClass> {
     let _p = profile("classify_name");
 
-    if let Some(bind_pat) = name.syntax().parent().and_then(ast::BindPat::cast) {
+    let parent = name.syntax().parent()?;
+
+    if let Some(bind_pat) = ast::BindPat::cast(parent.clone()) {
         if let Some(def) = sema.resolve_bind_pat_to_const(&bind_pat) {
             return Some(NameClass::ConstReference(Definition::ModuleDef(def)));
         }
     }
 
-    classify_name_inner(sema, name).map(NameClass::Definition)
-}
-
-fn classify_name_inner(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<Definition> {
-    let parent = name.syntax().parent()?;
-
     match_ast! {
         match parent {
             ast::Alias(it) => {
@@ -123,63 +126,73 @@ fn classify_name_inner(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Opti
                 let name_ref = path_segment.name_ref()?;
                 let name_ref_class = classify_name_ref(sema, &name_ref)?;
 
-                Some(name_ref_class.definition())
+                Some(NameClass::Definition(name_ref_class.definition()))
             },
             ast::BindPat(it) => {
                 let local = sema.to_def(&it)?;
-                Some(Definition::Local(local))
+
+                if let Some(record_field_pat) = it.syntax().parent().and_then(ast::RecordFieldPat::cast) {
+                    if record_field_pat.name_ref().is_none() {
+                        if let Some(field) = sema.resolve_record_field_pat(&record_field_pat) {
+                            let field = Definition::Field(field);
+                            return Some(NameClass::FieldShorthand { local, field });
+                        }
+                    }
+                }
+
+                Some(NameClass::Definition(Definition::Local(local)))
             },
             ast::RecordFieldDef(it) => {
                 let field: hir::Field = sema.to_def(&it)?;
-                Some(Definition::Field(field))
+                Some(NameClass::Definition(Definition::Field(field)))
             },
             ast::Module(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::StructDef(it) => {
                 let def: hir::Struct = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::UnionDef(it) => {
                 let def: hir::Union = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::EnumDef(it) => {
                 let def: hir::Enum = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::TraitDef(it) => {
                 let def: hir::Trait = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::StaticDef(it) => {
                 let def: hir::Static = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::EnumVariant(it) => {
                 let def: hir::EnumVariant = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::FnDef(it) => {
                 let def: hir::Function = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::ConstDef(it) => {
                 let def: hir::Const = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::TypeAliasDef(it) => {
                 let def: hir::TypeAlias = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::MacroCall(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::Macro(def))
+                Some(NameClass::Definition(Definition::Macro(def)))
             },
             ast::TypeParam(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::TypeParam(def))
+                Some(NameClass::Definition(Definition::TypeParam(def)))
             },
             _ => None,
         }
@@ -242,8 +255,14 @@ pub fn classify_name_ref(
     }
 
     if let Some(macro_call) = parent.ancestors().find_map(ast::MacroCall::cast) {
-        if let Some(macro_def) = sema.resolve_macro_call(&macro_call) {
-            return Some(NameRefClass::Definition(Definition::Macro(macro_def)));
+        if let Some(path) = macro_call.path() {
+            if path.qualifier().is_none() {
+                // Only use this to resolve single-segment macro calls like `foo!()`. Multi-segment
+                // paths are handled below (allowing `log<|>::info!` to resolve to the log crate).
+                if let Some(macro_def) = sema.resolve_macro_call(&macro_call) {
+                    return Some(NameRefClass::Definition(Definition::Macro(macro_def)));
+                }
+            }
         }
     }
 
diff --git a/crates/ra_ide_db/src/imports_locator.rs b/crates/ra_ide_db/src/imports_locator.rs
index bf0d8db60..1fba71ff8 100644
--- a/crates/ra_ide_db/src/imports_locator.rs
+++ b/crates/ra_ide_db/src/imports_locator.rs
@@ -1,7 +1,7 @@
 //! This module contains an import search funcionality that is provided to the ra_assists module.
 //! Later, this should be moved away to a separate crate that is accessible from the ra_assists module.
 
-use hir::{MacroDef, ModuleDef, Semantics};
+use hir::{Crate, MacroDef, ModuleDef, Semantics};
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, SyntaxKind::NAME};
 
@@ -11,57 +11,55 @@ use crate::{
     RootDatabase,
 };
 use either::Either;
+use rustc_hash::FxHashSet;
 
-pub struct ImportsLocator<'a> {
-    sema: Semantics<'a, RootDatabase>,
-}
-
-impl<'a> ImportsLocator<'a> {
-    pub fn new(db: &'a RootDatabase) -> Self {
-        Self { sema: Semantics::new(db) }
-    }
+pub fn find_imports<'a>(
+    sema: &Semantics<'a, RootDatabase>,
+    krate: Crate,
+    name_to_import: &str,
+) -> Vec<Either<ModuleDef, MacroDef>> {
+    let _p = profile("search_for_imports");
+    let db = sema.db;
 
-    pub fn find_imports(&mut self, name_to_import: &str) -> Vec<Either<ModuleDef, MacroDef>> {
-        let _p = profile("search_for_imports");
-        let db = self.sema.db;
+    // Query dependencies first.
+    let mut candidates: FxHashSet<_> =
+        krate.query_external_importables(db, name_to_import).collect();
 
-        let project_results = {
-            let mut query = Query::new(name_to_import.to_string());
-            query.exact();
-            query.limit(40);
-            symbol_index::world_symbols(db, query)
-        };
-        let lib_results = {
-            let mut query = Query::new(name_to_import.to_string());
-            query.libs();
-            query.exact();
-            query.limit(40);
-            symbol_index::world_symbols(db, query)
-        };
+    // Query the local crate using the symbol index.
+    let local_results = {
+        let mut query = Query::new(name_to_import.to_string());
+        query.exact();
+        query.limit(40);
+        symbol_index::crate_symbols(db, krate.into(), query)
+    };
 
-        project_results
+    candidates.extend(
+        local_results
             .into_iter()
-            .chain(lib_results.into_iter())
-            .filter_map(|import_candidate| self.get_name_definition(&import_candidate))
+            .filter_map(|import_candidate| get_name_definition(sema, &import_candidate))
             .filter_map(|name_definition_to_import| match name_definition_to_import {
                 Definition::ModuleDef(module_def) => Some(Either::Left(module_def)),
                 Definition::Macro(macro_def) => Some(Either::Right(macro_def)),
                 _ => None,
-            })
-            .collect()
-    }
+            }),
+    );
+
+    candidates.into_iter().collect()
+}
 
-    fn get_name_definition(&mut self, import_candidate: &FileSymbol) -> Option<Definition> {
-        let _p = profile("get_name_definition");
-        let file_id = import_candidate.file_id;
+fn get_name_definition<'a>(
+    sema: &Semantics<'a, RootDatabase>,
+    import_candidate: &FileSymbol,
+) -> Option<Definition> {
+    let _p = profile("get_name_definition");
+    let file_id = import_candidate.file_id;
 
-        let candidate_node = import_candidate.ptr.to_node(self.sema.parse(file_id).syntax());
-        let candidate_name_node = if candidate_node.kind() != NAME {
-            candidate_node.children().find(|it| it.kind() == NAME)?
-        } else {
-            candidate_node
-        };
-        let name = ast::Name::cast(candidate_name_node)?;
-        classify_name(&self.sema, &name)?.into_definition()
-    }
+    let candidate_node = import_candidate.ptr.to_node(sema.parse(file_id).syntax());
+    let candidate_name_node = if candidate_node.kind() != NAME {
+        candidate_node.children().find(|it| it.kind() == NAME)?
+    } else {
+        candidate_node
+    };
+    let name = ast::Name::cast(candidate_name_node)?;
+    classify_name(sema, &name)?.into_definition()
 }
diff --git a/crates/ra_ide_db/src/lib.rs b/crates/ra_ide_db/src/lib.rs
index 1b74e6558..6900cac73 100644
--- a/crates/ra_ide_db/src/lib.rs
+++ b/crates/ra_ide_db/src/lib.rs
@@ -11,15 +11,15 @@ pub mod imports_locator;
 pub mod source_change;
 mod wasm_shims;
 
-use std::sync::Arc;
+use std::{fmt, sync::Arc};
 
-use hir::db::{AstDatabase, DefDatabase};
+use hir::db::{AstDatabase, DefDatabase, HirDatabase};
 use ra_db::{
-    salsa::{self, Database, Durability},
-    Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath,
-    SourceDatabase, SourceRootId, Upcast,
+    salsa::{self, Durability},
+    Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase,
+    Upcast,
 };
-use rustc_hash::FxHashMap;
+use rustc_hash::FxHashSet;
 
 use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
 
@@ -33,14 +33,18 @@ use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
     hir::db::DefDatabaseStorage,
     hir::db::HirDatabaseStorage
 )]
-#[derive(Debug)]
 pub struct RootDatabase {
-    runtime: salsa::Runtime<RootDatabase>,
-    pub(crate) debug_data: Arc<DebugData>,
+    storage: salsa::Storage<RootDatabase>,
     pub last_gc: crate::wasm_shims::Instant,
     pub last_gc_check: crate::wasm_shims::Instant,
 }
 
+impl fmt::Debug for RootDatabase {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("RootDatabase").finish()
+    }
+}
+
 impl Upcast<dyn AstDatabase> for RootDatabase {
     fn upcast(&self) -> &(dyn AstDatabase + 'static) {
         &*self
@@ -53,41 +57,30 @@ impl Upcast<dyn DefDatabase> for RootDatabase {
     }
 }
 
+impl Upcast<dyn HirDatabase> for RootDatabase {
+    fn upcast(&self) -> &(dyn HirDatabase + 'static) {
+        &*self
+    }
+}
+
 impl FileLoader for RootDatabase {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        extern_id: ra_db::ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl salsa::Database for RootDatabase {
-    fn salsa_runtime(&self) -> &salsa::Runtime<RootDatabase> {
-        &self.runtime
-    }
-    fn salsa_runtime_mut(&mut self) -> &mut salsa::Runtime<Self> {
-        &mut self.runtime
-    }
     fn on_propagated_panic(&self) -> ! {
         Canceled::throw()
     }
-    fn salsa_event(&self, event: impl Fn() -> salsa::Event<RootDatabase>) {
-        match event().kind {
+    fn salsa_event(&self, event: salsa::Event) {
+        match event.kind {
             salsa::EventKind::DidValidateMemoizedValue { .. }
             | salsa::EventKind::WillExecute { .. } => {
                 self.check_canceled();
@@ -106,10 +99,9 @@ impl Default for RootDatabase {
 impl RootDatabase {
     pub fn new(lru_capacity: Option<usize>) -> RootDatabase {
         let mut db = RootDatabase {
-            runtime: salsa::Runtime::default(),
+            storage: salsa::Storage::default(),
             last_gc: crate::wasm_shims::Instant::now(),
             last_gc_check: crate::wasm_shims::Instant::now(),
-            debug_data: Default::default(),
         };
         db.set_crate_graph_with_durability(Default::default(), Durability::HIGH);
         db.set_local_roots_with_durability(Default::default(), Durability::HIGH);
@@ -120,19 +112,18 @@ impl RootDatabase {
 
     pub fn update_lru_capacity(&mut self, lru_capacity: Option<usize>) {
         let lru_capacity = lru_capacity.unwrap_or(ra_db::DEFAULT_LRU_CAP);
-        self.query_mut(ra_db::ParseQuery).set_lru_capacity(lru_capacity);
-        self.query_mut(hir::db::ParseMacroQuery).set_lru_capacity(lru_capacity);
-        self.query_mut(hir::db::MacroExpandQuery).set_lru_capacity(lru_capacity);
+        ra_db::ParseQuery.in_db_mut(self).set_lru_capacity(lru_capacity);
+        hir::db::ParseMacroQuery.in_db_mut(self).set_lru_capacity(lru_capacity);
+        hir::db::MacroExpandQuery.in_db_mut(self).set_lru_capacity(lru_capacity);
     }
 }
 
 impl salsa::ParallelDatabase for RootDatabase {
     fn snapshot(&self) -> salsa::Snapshot<RootDatabase> {
         salsa::Snapshot::new(RootDatabase {
-            runtime: self.runtime.snapshot(self),
+            storage: self.storage.snapshot(),
             last_gc: self.last_gc,
             last_gc_check: self.last_gc_check,
-            debug_data: Arc::clone(&self.debug_data),
         })
     }
 }
@@ -142,18 +133,7 @@ pub trait LineIndexDatabase: ra_db::SourceDatabase + CheckCanceled {
     fn line_index(&self, file_id: FileId) -> Arc<LineIndex>;
 }
 
-fn line_index(db: &impl LineIndexDatabase, file_id: FileId) -> Arc<LineIndex> {
+fn line_index(db: &dyn LineIndexDatabase, file_id: FileId) -> Arc<LineIndex> {
     let text = db.file_text(file_id);
     Arc::new(LineIndex::new(&*text))
 }
-
-#[derive(Debug, Default, Clone)]
-pub(crate) struct DebugData {
-    pub(crate) root_paths: FxHashMap<SourceRootId, String>,
-}
-
-impl DebugData {
-    pub(crate) fn merge(&mut self, other: DebugData) {
-        self.root_paths.extend(other.root_paths.into_iter());
-    }
-}
diff --git a/crates/ra_ide_db/src/search.rs b/crates/ra_ide_db/src/search.rs
index 335a1ad03..81553150b 100644
--- a/crates/ra_ide_db/src/search.rs
+++ b/crates/ra_ide_db/src/search.rs
@@ -157,14 +157,14 @@ impl Definition {
         if let Some(Visibility::Public) = vis {
             let source_root_id = db.file_source_root(file_id);
             let source_root = db.source_root(source_root_id);
-            let mut res = source_root.walk().map(|id| (id, None)).collect::<FxHashMap<_, _>>();
+            let mut res = source_root.iter().map(|id| (id, None)).collect::<FxHashMap<_, _>>();
 
             let krate = module.krate();
             for rev_dep in krate.reverse_dependencies(db) {
                 let root_file = rev_dep.root_file(db);
                 let source_root_id = db.file_source_root(root_file);
                 let source_root = db.source_root(source_root_id);
-                res.extend(source_root.walk().map(|id| (id, None)));
+                res.extend(source_root.iter().map(|id| (id, None)));
             }
             return SearchScope::new(res);
         }
@@ -180,20 +180,20 @@ impl Definition {
 
     pub fn find_usages(
         &self,
-        db: &RootDatabase,
+        sema: &Semantics<RootDatabase>,
         search_scope: Option<SearchScope>,
     ) -> Vec<Reference> {
         let _p = profile("Definition::find_usages");
 
         let search_scope = {
-            let base = self.search_scope(db);
+            let base = self.search_scope(sema.db);
             match search_scope {
                 None => base,
                 Some(scope) => base.intersection(&scope),
             }
         };
 
-        let name = match self.name(db) {
+        let name = match self.name(sema.db) {
             None => return Vec::new(),
             Some(it) => it.to_string(),
         };
@@ -202,11 +202,10 @@ impl Definition {
         let mut refs = vec![];
 
         for (file_id, search_range) in search_scope {
-            let text = db.file_text(file_id);
+            let text = sema.db.file_text(file_id);
             let search_range =
                 search_range.unwrap_or(TextRange::up_to(TextSize::of(text.as_str())));
 
-            let sema = Semantics::new(db);
             let tree = Lazy::new(|| sema.parse(file_id).syntax().clone());
 
             for (idx, _) in text.match_indices(pat) {
@@ -222,9 +221,6 @@ impl Definition {
                         continue;
                     };
 
-                // FIXME: reuse sb
-                // See https://github.com/rust-lang/rust/pull/68198#issuecomment-574269098
-
                 match classify_name_ref(&sema, &name_ref) {
                     Some(NameRefClass::Definition(def)) if &def == self => {
                         let kind = if is_record_lit_name_ref(&name_ref)
diff --git a/crates/ra_ide_db/src/source_change.rs b/crates/ra_ide_db/src/source_change.rs
index e713f4b7e..abb83f421 100644
--- a/crates/ra_ide_db/src/source_change.rs
+++ b/crates/ra_ide_db/src/source_change.rs
@@ -3,10 +3,10 @@
 //!
 //! It can be viewed as a dual for `AnalysisChange`.
 
-use ra_db::{FileId, RelativePathBuf, SourceRootId};
+use ra_db::FileId;
 use ra_text_edit::TextEdit;
 
-#[derive(Debug, Clone)]
+#[derive(Default, Debug, Clone)]
 pub struct SourceChange {
     pub source_file_edits: Vec<SourceFileEdit>,
     pub file_system_edits: Vec<FileSystemEdit>,
@@ -22,17 +22,6 @@ impl SourceChange {
     ) -> Self {
         SourceChange { source_file_edits, file_system_edits, is_snippet: false }
     }
-
-    /// Creates a new SourceChange with the given label,
-    /// containing only the given `SourceFileEdits`.
-    pub fn source_file_edits(edits: Vec<SourceFileEdit>) -> Self {
-        SourceChange { source_file_edits: edits, file_system_edits: vec![], is_snippet: false }
-    }
-    /// Creates a new SourceChange with the given label
-    /// from the given `FileId` and `TextEdit`
-    pub fn source_file_edit_from(file_id: FileId, edit: TextEdit) -> Self {
-        SourceFileEdit { file_id, edit }.into()
-    }
 }
 
 #[derive(Debug, Clone)]
@@ -43,18 +32,20 @@ pub struct SourceFileEdit {
 
 impl From<SourceFileEdit> for SourceChange {
     fn from(edit: SourceFileEdit) -> SourceChange {
-        SourceChange {
-            source_file_edits: vec![edit],
-            file_system_edits: Vec::new(),
-            is_snippet: false,
-        }
+        vec![edit].into()
+    }
+}
+
+impl From<Vec<SourceFileEdit>> for SourceChange {
+    fn from(source_file_edits: Vec<SourceFileEdit>) -> SourceChange {
+        SourceChange { source_file_edits, file_system_edits: Vec::new(), is_snippet: false }
     }
 }
 
 #[derive(Debug, Clone)]
 pub enum FileSystemEdit {
-    CreateFile { source_root: SourceRootId, path: RelativePathBuf },
-    MoveFile { src: FileId, dst_source_root: SourceRootId, dst_path: RelativePathBuf },
+    CreateFile { anchor: FileId, dst: String },
+    MoveFile { src: FileId, anchor: FileId, dst: String },
 }
 
 impl From<FileSystemEdit> for SourceChange {
diff --git a/crates/ra_ide_db/src/symbol_index.rs b/crates/ra_ide_db/src/symbol_index.rs
index acc31fe3b..131e2a128 100644
--- a/crates/ra_ide_db/src/symbol_index.rs
+++ b/crates/ra_ide_db/src/symbol_index.rs
@@ -29,18 +29,20 @@ use std::{
 };
 
 use fst::{self, Streamer};
+use hir::db::DefDatabase;
 use ra_db::{
     salsa::{self, ParallelDatabase},
-    FileId, SourceDatabaseExt, SourceRootId,
+    CrateId, FileId, SourceDatabaseExt, SourceRootId,
 };
+use ra_prof::profile;
 use ra_syntax::{
     ast::{self, NameOwner},
     match_ast, AstNode, Parse, SmolStr, SourceFile,
     SyntaxKind::{self, *},
     SyntaxNode, SyntaxNodePtr, TextRange, WalkEvent,
 };
-#[cfg(not(feature = "wasm"))]
 use rayon::prelude::*;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::RootDatabase;
 
@@ -85,21 +87,41 @@ impl Query {
 }
 
 #[salsa::query_group(SymbolsDatabaseStorage)]
-pub trait SymbolsDatabase: hir::db::HirDatabase {
+pub trait SymbolsDatabase: hir::db::HirDatabase + SourceDatabaseExt {
     fn file_symbols(&self, file_id: FileId) -> Arc<SymbolIndex>;
-    #[salsa::input]
-    fn library_symbols(&self, id: SourceRootId) -> Arc<SymbolIndex>;
+    fn library_symbols(&self) -> Arc<FxHashMap<SourceRootId, SymbolIndex>>;
     /// The set of "local" (that is, from the current workspace) roots.
     /// Files in local roots are assumed to change frequently.
     #[salsa::input]
-    fn local_roots(&self) -> Arc<Vec<SourceRootId>>;
+    fn local_roots(&self) -> Arc<FxHashSet<SourceRootId>>;
     /// The set of roots for crates.io libraries.
     /// Files in libraries are assumed to never change.
     #[salsa::input]
-    fn library_roots(&self) -> Arc<Vec<SourceRootId>>;
+    fn library_roots(&self) -> Arc<FxHashSet<SourceRootId>>;
+}
+
+fn library_symbols(db: &dyn SymbolsDatabase) -> Arc<FxHashMap<SourceRootId, SymbolIndex>> {
+    let _p = profile("library_symbols");
+
+    let roots = db.library_roots();
+    let res = roots
+        .iter()
+        .map(|&root_id| {
+            let root = db.source_root(root_id);
+            let files = root
+                .iter()
+                .map(|it| (it, SourceDatabaseExt::file_text(db, it)))
+                .collect::<Vec<_>>();
+            let symbol_index = SymbolIndex::for_files(
+                files.into_par_iter().map(|(file, text)| (file, SourceFile::parse(&text))),
+            );
+            (root_id, symbol_index)
+        })
+        .collect();
+    Arc::new(res)
 }
 
-fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex> {
+fn file_symbols(db: &dyn SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex> {
     db.check_canceled();
     let parse = db.parse(file_id);
 
@@ -110,6 +132,14 @@ fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex>
     Arc::new(SymbolIndex::new(symbols))
 }
 
+/// Need to wrap Snapshot to provide `Clone` impl for `map_with`
+struct Snap<DB>(DB);
+impl<DB: ParallelDatabase> Clone for Snap<salsa::Snapshot<DB>> {
+    fn clone(&self) -> Snap<salsa::Snapshot<DB>> {
+        Snap(self.0.snapshot())
+    }
+}
+
 // Feature: Workspace Symbol
 //
 // Uses fuzzy-search to find types, modules and functions by name across your
@@ -132,44 +162,51 @@ fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex>
 // | VS Code | kbd:[Ctrl+T]
 // |===
 pub fn world_symbols(db: &RootDatabase, query: Query) -> Vec<FileSymbol> {
-    /// Need to wrap Snapshot to provide `Clone` impl for `map_with`
-    struct Snap(salsa::Snapshot<RootDatabase>);
-    impl Clone for Snap {
-        fn clone(&self) -> Snap {
-            Snap(self.0.snapshot())
-        }
-    }
+    let _p = ra_prof::profile("world_symbols").detail(|| query.query.clone());
 
-    let buf: Vec<Arc<SymbolIndex>> = if query.libs {
-        let snap = Snap(db.snapshot());
-        #[cfg(not(feature = "wasm"))]
-        let buf = db
-            .library_roots()
-            .par_iter()
-            .map_with(snap, |db, &lib_id| db.0.library_symbols(lib_id))
-            .collect();
-
-        #[cfg(feature = "wasm")]
-        let buf = db.library_roots().iter().map(|&lib_id| snap.0.library_symbols(lib_id)).collect();
-
-        buf
+    let tmp1;
+    let tmp2;
+    let buf: Vec<&SymbolIndex> = if query.libs {
+        tmp1 = db.library_symbols();
+        tmp1.values().collect()
     } else {
         let mut files = Vec::new();
         for &root in db.local_roots().iter() {
             let sr = db.source_root(root);
-            files.extend(sr.walk())
+            files.extend(sr.iter())
         }
 
         let snap = Snap(db.snapshot());
-        #[cfg(not(feature = "wasm"))]
-        let buf =
-            files.par_iter().map_with(snap, |db, &file_id| db.0.file_symbols(file_id)).collect();
+        tmp2 = files
+            .par_iter()
+            .map_with(snap, |db, &file_id| db.0.file_symbols(file_id))
+            .collect::<Vec<_>>();
+        tmp2.iter().map(|it| &**it).collect()
+    };
+    query.search(&buf)
+}
 
-        #[cfg(feature = "wasm")]
-        let buf = files.iter().map(|&file_id| snap.0.file_symbols(file_id)).collect();
+pub fn crate_symbols(db: &RootDatabase, krate: CrateId, query: Query) -> Vec<FileSymbol> {
+    // FIXME(#4842): This now depends on CrateDefMap, why not build the entire symbol index from
+    // that instead?
+
+    let def_map = db.crate_def_map(krate);
+    let mut files = Vec::new();
+    let mut modules = vec![def_map.root];
+    while let Some(module) = modules.pop() {
+        let data = &def_map[module];
+        files.extend(data.origin.file_id());
+        modules.extend(data.children.values());
+    }
+
+    let snap = Snap(db.snapshot());
+
+    let buf = files
+        .par_iter()
+        .map_with(snap, |db, &file_id| db.0.file_symbols(file_id))
+        .collect::<Vec<_>>();
+    let buf = buf.iter().map(|it| &**it).collect::<Vec<_>>();
 
-        buf
-    };
     query.search(&buf)
 }
 
@@ -215,12 +252,8 @@ impl SymbolIndex {
             lhs_chars.cmp(rhs_chars)
         }
 
-        #[cfg(not(feature = "wasm"))]
         symbols.par_sort_by(cmp);
 
-        #[cfg(feature = "wasm")]
-        symbols.sort_by(cmp);
-
         let mut builder = fst::MapBuilder::memory();
 
         let mut last_batch_start = 0;
@@ -254,7 +287,6 @@ impl SymbolIndex {
         self.map.as_fst().size() + self.symbols.len() * mem::size_of::<FileSymbol>()
     }
 
-    #[cfg(not(feature = "wasm"))]
     pub(crate) fn for_files(
         files: impl ParallelIterator<Item = (FileId, Parse<ast::SourceFile>)>,
     ) -> SymbolIndex {
@@ -264,16 +296,6 @@ impl SymbolIndex {
         SymbolIndex::new(symbols)
     }
 
-    #[cfg(feature = "wasm")]
-    pub(crate) fn for_files(
-        files: impl Iterator<Item = (FileId, Parse<ast::SourceFile>)>,
-    ) -> SymbolIndex {
-        let symbols = files
-            .flat_map(|(file_id, file)| source_file_to_file_symbols(&file.tree(), file_id))
-            .collect::<Vec<_>>();
-        SymbolIndex::new(symbols)
-    }
-
     fn range_to_map_value(start: usize, end: usize) -> u64 {
         debug_assert![start <= (std::u32::MAX as usize)];
         debug_assert![end <= (std::u32::MAX as usize)];
@@ -289,7 +311,7 @@ impl SymbolIndex {
 }
 
 impl Query {
-    pub(crate) fn search(self, indices: &[Arc<SymbolIndex>]) -> Vec<FileSymbol> {
+    pub(crate) fn search(self, indices: &[&SymbolIndex]) -> Vec<FileSymbol> {
         let mut op = fst::map::OpBuilder::new();
         for file_symbols in indices.iter() {
             let automaton = fst::automaton::Subsequence::new(&self.lowercased);
@@ -298,9 +320,6 @@ impl Query {
         let mut stream = op.union();
         let mut res = Vec::new();
         while let Some((_, indexed_values)) = stream.next() {
-            if res.len() >= self.limit {
-                break;
-            }
             for indexed_value in indexed_values {
                 let symbol_index = &indices[indexed_value.index];
                 let (start, end) = SymbolIndex::map_value_to_range(indexed_value.value);
@@ -312,7 +331,11 @@ impl Query {
                     if self.exact && symbol.name != self.query {
                         continue;
                     }
+
                     res.push(symbol.clone());
+                    if res.len() >= self.limit {
+                        return res;
+                    }
                 }
             }
         }
@@ -321,10 +344,7 @@ impl Query {
 }
 
 fn is_type(kind: SyntaxKind) -> bool {
-    match kind {
-        STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF => true,
-        _ => false,
-    }
+    matches!(kind, STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF)
 }
 
 /// The actual data that is stored in the index. It should be as compact as
diff --git a/crates/ra_mbe/Cargo.toml b/crates/ra_mbe/Cargo.toml
index 4dec24914..a26746a19 100644
--- a/crates/ra_mbe/Cargo.toml
+++ b/crates/ra_mbe/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_mbe"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index 9c450eaba..dec7ba22e 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -9,6 +9,9 @@ mod syntax_bridge;
 mod tt_iter;
 mod subtree_source;
 
+#[cfg(test)]
+mod tests;
+
 pub use tt::{Delimiter, Punct};
 
 use crate::{
@@ -273,6 +276,3 @@ impl<T: Default> From<Result<T, ExpandError>> for ExpandResult<T> {
             .map_or_else(|e| ExpandResult(Default::default(), Some(e)), |it| ExpandResult(it, None))
     }
 }
-
-#[cfg(test)]
-mod tests;
diff --git a/crates/ra_mbe/src/mbe_expander/matcher.rs b/crates/ra_mbe/src/mbe_expander/matcher.rs
index 78f9efa1b..f9e515b81 100644
--- a/crates/ra_mbe/src/mbe_expander/matcher.rs
+++ b/crates/ra_mbe/src/mbe_expander/matcher.rs
@@ -260,7 +260,7 @@ impl<'a> TtIter<'a> {
             | ('|', '=', None)
             | ('|', '|', None) => {
                 let tt2 = self.next().unwrap().clone();
-                Ok(tt::Subtree { delimiter: None, token_trees: vec![tt.clone(), tt2] }.into())
+                Ok(tt::Subtree { delimiter: None, token_trees: vec![tt, tt2] }.into())
             }
             _ => Ok(tt),
         }
diff --git a/crates/ra_mbe/src/parser.rs b/crates/ra_mbe/src/parser.rs
index 034150432..1e5dafbdf 100644
--- a/crates/ra_mbe/src/parser.rs
+++ b/crates/ra_mbe/src/parser.rs
@@ -137,10 +137,7 @@ fn eat_fragment_kind<'a>(
 }
 
 fn is_boolean_literal(lit: &tt::Literal) -> bool {
-    match lit.text.as_str() {
-        "true" | "false" => true,
-        _ => false,
-    }
+    matches!(lit.text.as_str(), "true" | "false")
 }
 
 fn parse_repeat(src: &mut TtIter) -> Result<(Option<Separator>, RepeatKind), ExpandError> {
diff --git a/crates/ra_parser/Cargo.toml b/crates/ra_parser/Cargo.toml
index 0da581fd5..72ec3e4d9 100644
--- a/crates/ra_parser/Cargo.toml
+++ b/crates/ra_parser/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_parser"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index be0cd5661..caedeead0 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -18,9 +18,10 @@
 //! // fn foo() {}
 //! ```
 //!
-//! After adding a new inline-test, run `cargo collect-tests` to extract
-//! it as a standalone text-fixture into `tests/data/parser/inline`, and
-//! run `cargo test` once to create the "gold" value.
+//! After adding a new inline-test, run `cargo xtask codegen` to
+//! extract it as a standalone text-fixture into
+//! `crates/ra_syntax/test_data/parser/`, and run `cargo test` once to
+//! create the "gold" value.
 //!
 //! Coding convention: rules like `where_clause` always produce either a
 //! node or an error, rules like `opt_where_clause` may produce nothing.
@@ -72,10 +73,7 @@ pub(crate) mod fragments {
     // Parse a meta item , which excluded [], e.g : #[ MetaItem ]
     pub(crate) fn meta_item(p: &mut Parser) {
         fn is_delimiter(p: &mut Parser) -> bool {
-            match p.current() {
-                T!['{'] | T!['('] | T!['['] => true,
-                _ => false,
-            }
+            matches!(p.current(), T!['{'] | T!['('] | T!['['])
         }
 
         if is_delimiter(p) {
diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index d6e8df32a..6e72eea66 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -50,10 +50,8 @@ fn expr_no_struct(p: &mut Parser) {
 }
 
 fn is_expr_stmt_attr_allowed(kind: SyntaxKind) -> bool {
-    match kind {
-        BIN_EXPR | RANGE_EXPR | IF_EXPR => false,
-        _ => true,
-    }
+    let forbid = matches!(kind, BIN_EXPR | RANGE_EXPR);
+    !forbid
 }
 
 pub(super) fn stmt(p: &mut Parser, with_semi: StmtWithSemi) {
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 67a924de5..97642bc24 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -118,7 +118,22 @@ pub(super) fn maybe_item(p: &mut Parser, m: Marker, flavor: ItemFlavor) -> Resul
         && p.at_contextual_kw("default")
         && (match p.nth(1) {
             T![impl] => true,
-            T![fn] | T![type] => {
+            T![unsafe] => {
+                // test default_unsafe_impl
+                // default unsafe impl Foo {}
+
+                // test default_unsafe_fn
+                // impl T for Foo {
+                //     default unsafe fn foo() {}
+                // }
+                if p.nth(2) == T![impl] || p.nth(2) == T![fn] {
+                    p.bump_remap(T![default]);
+                    p.bump(T![unsafe]);
+                    has_mods = true;
+                }
+                false
+            }
+            T![fn] | T![type] | T![const] => {
                 if let ItemFlavor::Mod = flavor {
                     true
                 } else {
@@ -198,6 +213,9 @@ pub(super) fn maybe_item(p: &mut Parser, m: Marker, flavor: ItemFlavor) -> Resul
         //     default type T = Bar;
         //     default fn foo() {}
         // }
+        T![const] => {
+            consts::const_def(p, m);
+        }
 
         // test unsafe_default_impl
         // unsafe default impl Foo {}
diff --git a/crates/ra_parser/src/grammar/paths.rs b/crates/ra_parser/src/grammar/paths.rs
index 332acc1a0..b503af1dc 100644
--- a/crates/ra_parser/src/grammar/paths.rs
+++ b/crates/ra_parser/src/grammar/paths.rs
@@ -3,7 +3,7 @@
 use super::*;
 
 pub(super) const PATH_FIRST: TokenSet =
-    token_set![IDENT, SELF_KW, SUPER_KW, CRATE_KW, COLON, L_ANGLE];
+    token_set![IDENT, T![self], T![super], T![crate], T![:], T![<]];
 
 pub(super) fn is_path_start(p: &Parser) -> bool {
     is_use_path_start(p) || p.at(T![<])
@@ -41,10 +41,7 @@ fn path(p: &mut Parser, mode: Mode) {
     path_segment(p, mode, true);
     let mut qual = path.complete(p, PATH);
     loop {
-        let use_tree = match p.nth(2) {
-            T![*] | T!['{'] => true,
-            _ => false,
-        };
+        let use_tree = matches!(p.nth(2), T![*] | T!['{']);
         if p.at(T![::]) && !use_tree {
             let path = qual.precede(p);
             p.bump(T![::]);
@@ -73,8 +70,10 @@ fn path_segment(p: &mut Parser, mode: Mode, first: bool) {
         }
         p.expect(T![>]);
     } else {
+        let mut empty = true;
         if first {
             p.eat(T![::]);
+            empty = false;
         }
         match p.current() {
             IDENT => {
@@ -86,6 +85,12 @@ fn path_segment(p: &mut Parser, mode: Mode, first: bool) {
             T![self] | T![super] | T![crate] => p.bump_any(),
             _ => {
                 p.err_recover("expected identifier", items::ITEM_RECOVERY_SET);
+                if empty {
+                    // test_err empty_segment
+                    // use crate::;
+                    m.abandon(p);
+                    return;
+                }
             }
         };
     }
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 68fb2fc73..427c0eb49 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -4,7 +4,7 @@ use super::*;
 
 pub(super) const PATTERN_FIRST: TokenSet = expressions::LITERAL_FIRST
     .union(paths::PATH_FIRST)
-    .union(token_set![BOX_KW, REF_KW, MUT_KW, L_PAREN, L_BRACK, AMP, UNDERSCORE, MINUS, DOT]);
+    .union(token_set![T![box], T![ref], T![mut], T!['('], T!['['], T![&], T![_], T![-], T![.]]);
 
 pub(crate) fn pattern(p: &mut Parser) {
     pattern_r(p, PAT_RECOVERY_SET);
@@ -88,7 +88,9 @@ fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option<CompletedMarker> {
             _ => bind_pat(p, true),
         },
 
-        _ if paths::is_use_path_start(p) => path_or_macro_pat(p),
+        // test type_path_in_pattern
+        // fn main() { let <_>::Foo = (); }
+        _ if paths::is_path_start(p) => path_or_macro_pat(p),
         _ if is_literal_pat_start(p) => literal_pat(p),
 
         T![.] if p.at(T![..]) => dot_dot_pat(p),
@@ -138,7 +140,7 @@ fn literal_pat(p: &mut Parser) -> CompletedMarker {
 //     let Bar(..) = ();
 // }
 fn path_or_macro_pat(p: &mut Parser) -> CompletedMarker {
-    assert!(paths::is_use_path_start(p));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     let kind = match p.current() {
diff --git a/crates/ra_parser/src/grammar/type_params.rs b/crates/ra_parser/src/grammar/type_params.rs
index 50e4900c3..d1330d4b9 100644
--- a/crates/ra_parser/src/grammar/type_params.rs
+++ b/crates/ra_parser/src/grammar/type_params.rs
@@ -169,10 +169,7 @@ fn is_where_predicate(p: &mut Parser) -> bool {
 }
 
 fn is_where_clause_end(p: &mut Parser) -> bool {
-    match p.current() {
-        T!['{'] | T![;] | T![=] => true,
-        _ => false,
-    }
+    matches!(p.current(), T!['{'] | T![;] | T![=])
 }
 
 fn where_predicate(p: &mut Parser) {
@@ -191,10 +188,14 @@ fn where_predicate(p: &mut Parser) {
         }
         _ => {
             // test where_pred_for
-            // fn test<F>()
+            // fn for_trait<F>()
             // where
             //    for<'a> F: Fn(&'a str)
             // { }
+            if p.at(T![for]) {
+                types::for_binder(p);
+            }
+
             types::type_(p);
 
             if p.at(T![:]) {
diff --git a/crates/ra_parser/src/grammar/types.rs b/crates/ra_parser/src/grammar/types.rs
index fe1a039cb..9e8e3bd97 100644
--- a/crates/ra_parser/src/grammar/types.rs
+++ b/crates/ra_parser/src/grammar/types.rs
@@ -216,19 +216,21 @@ pub(super) fn for_binder(p: &mut Parser) {
 
 // test for_type
 // type A = for<'a> fn() -> ();
-// fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
-// fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
-// fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
+// type B = for<'a> unsafe extern "C" fn(&'a ()) -> ();
+// type Obj = for<'a> PartialEq<&'a i32>;
 pub(super) fn for_type(p: &mut Parser) {
     assert!(p.at(T![for]));
     let m = p.start();
     for_binder(p);
     match p.current() {
-        T![fn] | T![unsafe] | T![extern] => fn_pointer_type(p),
-        T![&] => reference_type(p),
-        _ if paths::is_path_start(p) => path_type_(p, false),
-        _ => p.error("expected a path"),
+        T![fn] | T![unsafe] | T![extern] => {}
+        // OK: legacy trait object format
+        _ if paths::is_use_path_start(p) => {}
+        _ => {
+            p.error("expected a function pointer or path");
+        }
     }
+    type_no_bounds(p);
     m.complete(p, FOR_TYPE);
 }
 
diff --git a/crates/ra_parser/src/parser.rs b/crates/ra_parser/src/parser.rs
index 4f59b0a23..d797f2cc9 100644
--- a/crates/ra_parser/src/parser.rs
+++ b/crates/ra_parser/src/parser.rs
@@ -127,17 +127,24 @@ impl<'t> Parser<'t> {
 
     fn at_composite2(&self, n: usize, k1: SyntaxKind, k2: SyntaxKind) -> bool {
         let t1 = self.token_source.lookahead_nth(n);
+        if t1.kind != k1 || !t1.is_jointed_to_next {
+            return false;
+        }
         let t2 = self.token_source.lookahead_nth(n + 1);
-        t1.kind == k1 && t1.is_jointed_to_next && t2.kind == k2
+        t2.kind == k2
     }
 
     fn at_composite3(&self, n: usize, k1: SyntaxKind, k2: SyntaxKind, k3: SyntaxKind) -> bool {
         let t1 = self.token_source.lookahead_nth(n);
+        if t1.kind != k1 || !t1.is_jointed_to_next {
+            return false;
+        }
         let t2 = self.token_source.lookahead_nth(n + 1);
+        if t2.kind != k2 || !t2.is_jointed_to_next {
+            return false;
+        }
         let t3 = self.token_source.lookahead_nth(n + 2);
-        (t1.kind == k1 && t1.is_jointed_to_next)
-            && (t2.kind == k2 && t2.is_jointed_to_next)
-            && t3.kind == k3
+        t3.kind == k3
     }
 
     /// Checks if the current token is in `kinds`.
diff --git a/crates/ra_parser/src/syntax_kind.rs b/crates/ra_parser/src/syntax_kind.rs
index 8d6bd057b..63204436c 100644
--- a/crates/ra_parser/src/syntax_kind.rs
+++ b/crates/ra_parser/src/syntax_kind.rs
@@ -20,9 +20,6 @@ impl From<SyntaxKind> for u16 {
 
 impl SyntaxKind {
     pub fn is_trivia(self) -> bool {
-        match self {
-            SyntaxKind::WHITESPACE | SyntaxKind::COMMENT => true,
-            _ => false,
-        }
+        matches!(self, SyntaxKind::WHITESPACE | SyntaxKind::COMMENT)
     }
 }
diff --git a/crates/ra_proc_macro/Cargo.toml b/crates/ra_proc_macro/Cargo.toml
index d009ceb82..c4b6e9e7b 100644
--- a/crates/ra_proc_macro/Cargo.toml
+++ b/crates/ra_proc_macro/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_proc_macro"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_proc_macro_srv/Cargo.toml b/crates/ra_proc_macro_srv/Cargo.toml
index bb3003278..12ce497f8 100644
--- a/crates/ra_proc_macro_srv/Cargo.toml
+++ b/crates/ra_proc_macro_srv/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_proc_macro_srv"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -22,3 +23,4 @@ cargo_metadata = "0.10.0"
 difference = "2.0.0"
 # used as proc macro test target
 serde_derive = "1.0.106"
+ra_toolchain = { path = "../ra_toolchain" }
diff --git a/crates/ra_proc_macro_srv/src/dylib.rs b/crates/ra_proc_macro_srv/src/dylib.rs
index aa84e951c..1addbbd54 100644
--- a/crates/ra_proc_macro_srv/src/dylib.rs
+++ b/crates/ra_proc_macro_srv/src/dylib.rs
@@ -45,7 +45,7 @@ fn find_registrar_symbol(file: &Path) -> io::Result<Option<String>> {
                     // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/dlsym.3.html
                     // Unlike other dyld API's, the symbol name passed to dlsym() must NOT be
                     // prepended with an underscore.
-                    if s.name.starts_with("_") {
+                    if s.name.starts_with('_') {
                         &s.name[1..]
                     } else {
                         &s.name
diff --git a/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt b/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
index bc010cfe9..e6fd21610 100644
--- a/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
+++ b/crates/ra_proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
@@ -14,7 +14,7 @@ SUBTREE $
       PUNCH   , [alone] 4294967295
       IDENT   unused_qualifications 4294967295
   IDENT   const 4294967295
-  IDENT   _IMPL_SERIALIZE_FOR_Foo 4294967295
+  IDENT   _ 4294967295
   PUNCH   : [alone] 4294967295
   SUBTREE () 4294967295
   PUNCH   = [alone] 4294967295
diff --git a/crates/ra_proc_macro_srv/src/tests/mod.rs b/crates/ra_proc_macro_srv/src/tests/mod.rs
index 82cefbb29..8e6f28abd 100644
--- a/crates/ra_proc_macro_srv/src/tests/mod.rs
+++ b/crates/ra_proc_macro_srv/src/tests/mod.rs
@@ -11,7 +11,7 @@ fn test_derive_serialize_proc_macro() {
         "serde_derive",
         "Serialize",
         "1.0",
-        r##"struct Foo {}"##,
+        r"struct Foo {}",
         include_str!("fixtures/test_serialize_proc_macro.txt"),
     );
 }
@@ -22,9 +22,7 @@ fn test_derive_serialize_proc_macro_failed() {
         "serde_derive",
         "Serialize",
         "1.0",
-        r##"
-    struct {}
-"##,
+        r"struct {}",
         r##"
 SUBTREE $
   IDENT   compile_error 4294967295
diff --git a/crates/ra_proc_macro_srv/src/tests/utils.rs b/crates/ra_proc_macro_srv/src/tests/utils.rs
index 84348b5de..dcb00671f 100644
--- a/crates/ra_proc_macro_srv/src/tests/utils.rs
+++ b/crates/ra_proc_macro_srv/src/tests/utils.rs
@@ -2,7 +2,6 @@
 
 use crate::dylib;
 use crate::ProcMacroSrv;
-pub use difference::Changeset as __Changeset;
 use ra_proc_macro::ListMacrosTask;
 use std::str::FromStr;
 use test_utils::assert_eq_text;
@@ -13,7 +12,7 @@ mod fixtures {
 
     // Use current project metadata to get the proc-macro dylib path
     pub fn dylib_path(crate_name: &str, version: &str) -> std::path::PathBuf {
-        let command = Command::new("cargo")
+        let command = Command::new(ra_toolchain::cargo())
             .args(&["check", "--message-format", "json"])
             .output()
             .unwrap()
@@ -45,12 +44,12 @@ pub fn assert_expand(
     crate_name: &str,
     macro_name: &str,
     version: &str,
-    fixture: &str,
+    ra_fixture: &str,
     expect: &str,
 ) {
     let path = fixtures::dylib_path(crate_name, version);
     let expander = dylib::Expander::new(&path).unwrap();
-    let fixture = parse_string(fixture).unwrap();
+    let fixture = parse_string(ra_fixture).unwrap();
 
     let res = expander.expand(macro_name, &fixture.subtree, None).unwrap();
     assert_eq_text!(&format!("{:?}", res), &expect.trim());
diff --git a/crates/ra_prof/Cargo.toml b/crates/ra_prof/Cargo.toml
index c33b5121a..b3d52985a 100644
--- a/crates/ra_prof/Cargo.toml
+++ b/crates/ra_prof/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_prof"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -12,6 +13,7 @@ doctest = false
 ra_arena = { path = "../ra_arena" }
 once_cell = "1.3.1"
 backtrace = { version = "0.3.44", optional = true }
+mimalloc = { version = "0.1.19", default-features = false, optional = true }
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]
 jemallocator = { version = "0.3.2", optional = true }
@@ -20,3 +22,9 @@ jemalloc-ctl = { version = "0.3.3", optional = true }
 [features]
 jemalloc = [ "jemallocator", "jemalloc-ctl" ]
 cpu_profiler = []
+
+# Uncomment to enable for the whole crate graph
+# default = [ "backtrace" ]
+# default = [ "jemalloc" ]
+# default = [ "mimalloc" ]
+# default = [ "cpu_profiler" ]
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index 89df7f04b..b54531b4e 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -19,6 +19,10 @@ pub use crate::{
 #[global_allocator]
 static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
 
+#[cfg(all(feature = "mimalloc"))]
+#[global_allocator]
+static ALLOC: mimalloc::MiMalloc = mimalloc::MiMalloc;
+
 /// Prints backtrace to stderr, useful for debugging.
 #[cfg(feature = "backtrace")]
 pub fn print_backtrace() {
@@ -43,6 +47,7 @@ pub struct Scope {
 }
 
 impl Scope {
+    #[must_use]
     pub fn enter() -> Scope {
         let prev = IN_SCOPE.with(|slot| std::mem::replace(&mut *slot.borrow_mut(), true));
         Scope { prev }
@@ -65,7 +70,8 @@ impl Drop for Scope {
 /// 2. Build with `cpu_profiler` feature.
 /// 3. Tun the code, the *raw* output would be in the `./out.profile` file.
 /// 4. Install pprof for visualization (https://github.com/google/pprof).
-/// 5. Use something like `pprof -svg target/release/rust-analyzer ./out.profile` to see the results.
+/// 5. Bump sampling frequency to once per ms: `export CPUPROFILE_FREQUENCY=1000`
+/// 6. Use something like `pprof -svg target/release/rust-analyzer ./out.profile` to see the results.
 ///
 /// For example, here's how I run profiling on NixOS:
 ///
@@ -73,11 +79,16 @@ impl Drop for Scope {
 /// $ nix-shell -p gperftools --run \
 ///     'cargo run --release -p rust-analyzer -- parse < ~/projects/rustbench/parser.rs > /dev/null'
 /// ```
+///
+/// See this diff for how to profile completions:
+///
+/// https://github.com/rust-analyzer/rust-analyzer/pull/5306
 #[derive(Debug)]
 pub struct CpuProfiler {
     _private: (),
 }
 
+#[must_use]
 pub fn cpu_profiler() -> CpuProfiler {
     #[cfg(feature = "cpu_profiler")]
     {
diff --git a/crates/ra_project_model/Cargo.toml b/crates/ra_project_model/Cargo.toml
index e4a60f4c0..827eb7e28 100644
--- a/crates/ra_project_model/Cargo.toml
+++ b/crates/ra_project_model/Cargo.toml
@@ -3,6 +3,7 @@ edition = "2018"
 name = "ra_project_model"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
@@ -18,6 +19,8 @@ ra_cfg = { path = "../ra_cfg" }
 ra_db = { path = "../ra_db" }
 ra_toolchain = { path = "../ra_toolchain" }
 ra_proc_macro =  { path = "../ra_proc_macro" }
+paths =  { path = "../paths" }
+stdx =  { path = "../stdx" }
 
 serde = { version = "1.0.106", features = ["derive"] }
 serde_json = "1.0.48"
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index a306ce95f..4182ca156 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -9,6 +9,7 @@ use std::{
 
 use anyhow::{Context, Result};
 use cargo_metadata::{BuildScript, CargoOpt, Message, MetadataCommand, PackageId};
+use paths::{AbsPath, AbsPathBuf};
 use ra_arena::{Arena, Idx};
 use ra_db::Edition;
 use rustc_hash::FxHashMap;
@@ -20,11 +21,14 @@ use rustc_hash::FxHashMap;
 /// `CrateGraph`. `CrateGraph` is lower-level: it knows only about the crates,
 /// while this knows about `Packages` & `Targets`: purely cargo-related
 /// concepts.
-#[derive(Debug, Clone)]
+///
+/// We use absolute paths here, `cargo metadata` guarantees to always produce
+/// abs paths.
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct CargoWorkspace {
     packages: Arena<PackageData>,
     targets: Arena<TargetData>,
-    workspace_root: PathBuf,
+    workspace_root: AbsPathBuf,
 }
 
 impl ops::Index<Package> for CargoWorkspace {
@@ -41,7 +45,7 @@ impl ops::Index<Target> for CargoWorkspace {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Default, Clone, Debug, PartialEq, Eq)]
 pub struct CargoConfig {
     /// Do not activate the `default` feature.
     pub no_default_features: bool,
@@ -60,48 +64,36 @@ pub struct CargoConfig {
     pub target: Option<String>,
 }
 
-impl Default for CargoConfig {
-    fn default() -> Self {
-        CargoConfig {
-            no_default_features: false,
-            all_features: true,
-            features: Vec::new(),
-            load_out_dirs_from_check: false,
-            target: None,
-        }
-    }
-}
-
 pub type Package = Idx<PackageData>;
 
 pub type Target = Idx<TargetData>;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct PackageData {
     pub version: String,
     pub name: String,
-    pub manifest: PathBuf,
+    pub manifest: AbsPathBuf,
     pub targets: Vec<Target>,
     pub is_member: bool,
     pub dependencies: Vec<PackageDependency>,
     pub edition: Edition,
     pub features: Vec<String>,
     pub cfgs: Vec<String>,
-    pub out_dir: Option<PathBuf>,
-    pub proc_macro_dylib_path: Option<PathBuf>,
+    pub out_dir: Option<AbsPathBuf>,
+    pub proc_macro_dylib_path: Option<AbsPathBuf>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct PackageDependency {
     pub pkg: Package,
     pub name: String,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct TargetData {
     pub package: Package,
     pub name: String,
-    pub root: PathBuf,
+    pub root: AbsPathBuf,
     pub kind: TargetKind,
     pub is_proc_macro: bool,
 }
@@ -135,19 +127,19 @@ impl TargetKind {
 }
 
 impl PackageData {
-    pub fn root(&self) -> &Path {
+    pub fn root(&self) -> &AbsPath {
         self.manifest.parent().unwrap()
     }
 }
 
 impl CargoWorkspace {
     pub fn from_cargo_metadata(
-        cargo_toml: &Path,
+        cargo_toml: &AbsPath,
         cargo_features: &CargoConfig,
     ) -> Result<CargoWorkspace> {
         let mut meta = MetadataCommand::new();
         meta.cargo_path(ra_toolchain::cargo());
-        meta.manifest_path(cargo_toml);
+        meta.manifest_path(cargo_toml.to_path_buf());
         if cargo_features.all_features {
             meta.features(CargoOpt::AllFeatures);
         } else if cargo_features.no_default_features {
@@ -158,12 +150,12 @@ impl CargoWorkspace {
             meta.features(CargoOpt::SomeFeatures(cargo_features.features.clone()));
         }
         if let Some(parent) = cargo_toml.parent() {
-            meta.current_dir(parent);
+            meta.current_dir(parent.to_path_buf());
         }
         if let Some(target) = cargo_features.target.as_ref() {
             meta.other_options(vec![String::from("--filter-platform"), target.clone()]);
         }
-        let meta = meta.exec().with_context(|| {
+        let mut meta = meta.exec().with_context(|| {
             format!("Failed to run `cargo metadata --manifest-path {}`", cargo_toml.display())
         })?;
 
@@ -183,6 +175,7 @@ impl CargoWorkspace {
 
         let ws_members = &meta.workspace_members;
 
+        meta.packages.sort_by(|a, b| a.id.cmp(&b.id));
         for meta_pkg in meta.packages {
             let cargo_metadata::Package { id, edition, name, manifest_path, version, .. } =
                 meta_pkg;
@@ -193,7 +186,7 @@ impl CargoWorkspace {
             let pkg = packages.alloc(PackageData {
                 name,
                 version: version.to_string(),
-                manifest: manifest_path,
+                manifest: AbsPathBuf::assert(manifest_path),
                 targets: Vec::new(),
                 is_member,
                 edition,
@@ -210,7 +203,7 @@ impl CargoWorkspace {
                 let tgt = targets.alloc(TargetData {
                     package: pkg,
                     name: meta_tgt.name,
-                    root: meta_tgt.src_path.clone(),
+                    root: AbsPathBuf::assert(meta_tgt.src_path.clone()),
                     kind: TargetKind::new(meta_tgt.kind.as_slice()),
                     is_proc_macro,
                 });
@@ -218,7 +211,7 @@ impl CargoWorkspace {
             }
         }
         let resolve = meta.resolve.expect("metadata executed with deps");
-        for node in resolve.nodes {
+        for mut node in resolve.nodes {
             let source = match pkg_by_id.get(&node.id) {
                 Some(&src) => src,
                 // FIXME: replace this and a similar branch below with `.unwrap`, once
@@ -229,6 +222,7 @@ impl CargoWorkspace {
                     continue;
                 }
             };
+            node.deps.sort_by(|a, b| a.pkg.cmp(&b.pkg));
             for dep_node in node.deps {
                 let pkg = match pkg_by_id.get(&dep_node.pkg) {
                     Some(&pkg) => pkg,
@@ -246,21 +240,22 @@ impl CargoWorkspace {
             packages[source].features.extend(node.features);
         }
 
-        Ok(CargoWorkspace { packages, targets, workspace_root: meta.workspace_root })
+        let workspace_root = AbsPathBuf::assert(meta.workspace_root);
+        Ok(CargoWorkspace { packages, targets, workspace_root: workspace_root })
     }
 
     pub fn packages<'a>(&'a self) -> impl Iterator<Item = Package> + ExactSizeIterator + 'a {
         self.packages.iter().map(|(id, _pkg)| id)
     }
 
-    pub fn target_by_root(&self, root: &Path) -> Option<Target> {
+    pub fn target_by_root(&self, root: &AbsPath) -> Option<Target> {
         self.packages()
-            .filter_map(|pkg| self[pkg].targets.iter().find(|&&it| self[it].root == root))
+            .filter_map(|pkg| self[pkg].targets.iter().find(|&&it| &self[it].root == root))
             .next()
             .copied()
     }
 
-    pub fn workspace_root(&self) -> &Path {
+    pub fn workspace_root(&self) -> &AbsPath {
         &self.workspace_root
     }
 
@@ -279,8 +274,8 @@ impl CargoWorkspace {
 
 #[derive(Debug, Clone, Default)]
 pub struct ExternResources {
-    out_dirs: FxHashMap<PackageId, PathBuf>,
-    proc_dylib_paths: FxHashMap<PackageId, PathBuf>,
+    out_dirs: FxHashMap<PackageId, AbsPathBuf>,
+    proc_dylib_paths: FxHashMap<PackageId, AbsPathBuf>,
     cfgs: FxHashMap<PackageId, Vec<String>>,
 }
 
@@ -308,8 +303,13 @@ pub fn load_extern_resources(
         if let Ok(message) = message {
             match message {
                 Message::BuildScriptExecuted(BuildScript { package_id, out_dir, cfgs, .. }) => {
-                    res.out_dirs.insert(package_id.clone(), out_dir);
-                    res.cfgs.insert(package_id, cfgs);
+                    // cargo_metadata crate returns default (empty) path for
+                    // older cargos, which is not absolute, so work around that.
+                    if out_dir != PathBuf::default() {
+                        let out_dir = AbsPathBuf::assert(out_dir);
+                        res.out_dirs.insert(package_id.clone(), out_dir);
+                        res.cfgs.insert(package_id, cfgs);
+                    }
                 }
                 Message::CompilerArtifact(message) => {
                     if message.target.kind.contains(&"proc-macro".to_string()) {
@@ -317,7 +317,8 @@ pub fn load_extern_resources(
                         // Skip rmeta file
                         if let Some(filename) = message.filenames.iter().find(|name| is_dylib(name))
                         {
-                            res.proc_dylib_paths.insert(package_id, filename.clone());
+                            let filename = AbsPathBuf::assert(filename.clone());
+                            res.proc_dylib_paths.insert(package_id, filename);
                         }
                     }
                 }
diff --git a/crates/ra_project_model/src/json_project.rs b/crates/ra_project_model/src/json_project.rs
deleted file mode 100644
index b030c8a6a..000000000
--- a/crates/ra_project_model/src/json_project.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-//! FIXME: write short doc here
-
-use std::path::PathBuf;
-
-use rustc_hash::{FxHashMap, FxHashSet};
-use serde::Deserialize;
-
-/// A root points to the directory which contains Rust crates. rust-analyzer watches all files in
-/// all roots. Roots might be nested.
-#[derive(Clone, Debug, Deserialize)]
-#[serde(transparent)]
-pub struct Root {
-    pub(crate) path: PathBuf,
-}
-
-/// A crate points to the root module of a crate and lists the dependencies of the crate. This is
-/// useful in creating the crate graph.
-#[derive(Clone, Debug, Deserialize)]
-pub struct Crate {
-    pub(crate) root_module: PathBuf,
-    pub(crate) edition: Edition,
-    pub(crate) deps: Vec<Dep>,
-    pub(crate) atom_cfgs: FxHashSet<String>,
-    pub(crate) key_value_cfgs: FxHashMap<String, String>,
-    pub(crate) out_dir: Option<PathBuf>,
-    pub(crate) proc_macro_dylib_path: Option<PathBuf>,
-}
-
-#[derive(Clone, Copy, Debug, Deserialize)]
-#[serde(rename = "edition")]
-pub enum Edition {
-    #[serde(rename = "2015")]
-    Edition2015,
-    #[serde(rename = "2018")]
-    Edition2018,
-}
-
-/// Identifies a crate by position in the crates array.
-#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd)]
-#[serde(transparent)]
-pub struct CrateId(pub usize);
-
-/// A dependency of a crate, identified by its id in the crates array and name.
-#[derive(Clone, Debug, Deserialize)]
-pub struct Dep {
-    #[serde(rename = "crate")]
-    pub(crate) krate: CrateId,
-    pub(crate) name: String,
-}
-
-/// Roots and crates that compose this Rust project.
-#[derive(Clone, Debug, Deserialize)]
-pub struct JsonProject {
-    pub(crate) roots: Vec<Root>,
-    pub(crate) crates: Vec<Crate>,
-}
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index a2e9f65ef..b9c5424bf 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -1,35 +1,35 @@
 //! FIXME: write short doc here
 
 mod cargo_workspace;
-mod json_project;
+mod project_json;
 mod sysroot;
 
 use std::{
-    fs::{read_dir, File, ReadDir},
-    io::{self, BufReader},
-    path::{Path, PathBuf},
+    fs::{self, read_dir, ReadDir},
+    io,
+    path::Path,
     process::{Command, Output},
 };
 
 use anyhow::{bail, Context, Result};
+use paths::{AbsPath, AbsPathBuf};
 use ra_cfg::CfgOptions;
-use ra_db::{CrateGraph, CrateName, Edition, Env, ExternSource, ExternSourceId, FileId};
-use rustc_hash::FxHashMap;
-use serde_json::from_reader;
+use ra_db::{CrateGraph, CrateId, CrateName, Edition, Env, FileId};
+use rustc_hash::{FxHashMap, FxHashSet};
 
 pub use crate::{
     cargo_workspace::{CargoConfig, CargoWorkspace, Package, Target, TargetKind},
-    json_project::JsonProject,
+    project_json::{ProjectJson, ProjectJsonData},
     sysroot::Sysroot,
 };
 pub use ra_proc_macro::ProcMacroClient;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub enum ProjectWorkspace {
     /// Project workspace was discovered by running `cargo metadata` and `rustc --print sysroot`.
     Cargo { cargo: CargoWorkspace, sysroot: Sysroot },
     /// Project workspace was manually specified using a `rust-project.json` file.
-    Json { project: JsonProject },
+    Json { project: ProjectJson },
 }
 
 /// `PackageRoot` describes a package root folder.
@@ -38,44 +38,48 @@ pub enum ProjectWorkspace {
 #[derive(Debug, Clone)]
 pub struct PackageRoot {
     /// Path to the root folder
-    path: PathBuf,
+    path: AbsPathBuf,
     /// Is a member of the current workspace
     is_member: bool,
+    out_dir: Option<AbsPathBuf>,
 }
 impl PackageRoot {
-    pub fn new_member(path: PathBuf) -> PackageRoot {
-        Self { path, is_member: true }
+    pub fn new_member(path: AbsPathBuf) -> PackageRoot {
+        Self { path, is_member: true, out_dir: None }
     }
-    pub fn new_non_member(path: PathBuf) -> PackageRoot {
-        Self { path, is_member: false }
+    pub fn new_non_member(path: AbsPathBuf) -> PackageRoot {
+        Self { path, is_member: false, out_dir: None }
     }
-    pub fn path(&self) -> &Path {
+    pub fn path(&self) -> &AbsPath {
         &self.path
     }
+    pub fn out_dir(&self) -> Option<&AbsPath> {
+        self.out_dir.as_deref()
+    }
     pub fn is_member(&self) -> bool {
         self.is_member
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum ProjectRoot {
-    ProjectJson(PathBuf),
-    CargoToml(PathBuf),
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
+pub enum ProjectManifest {
+    ProjectJson(AbsPathBuf),
+    CargoToml(AbsPathBuf),
 }
 
-impl ProjectRoot {
-    pub fn from_manifest_file(path: PathBuf) -> Result<ProjectRoot> {
+impl ProjectManifest {
+    pub fn from_manifest_file(path: AbsPathBuf) -> Result<ProjectManifest> {
         if path.ends_with("rust-project.json") {
-            return Ok(ProjectRoot::ProjectJson(path));
+            return Ok(ProjectManifest::ProjectJson(path));
         }
         if path.ends_with("Cargo.toml") {
-            return Ok(ProjectRoot::CargoToml(path));
+            return Ok(ProjectManifest::CargoToml(path));
         }
         bail!("project root must point to Cargo.toml or rust-project.json: {}", path.display())
     }
 
-    pub fn discover_single(path: &Path) -> Result<ProjectRoot> {
-        let mut candidates = ProjectRoot::discover(path)?;
+    pub fn discover_single(path: &AbsPath) -> Result<ProjectManifest> {
+        let mut candidates = ProjectManifest::discover(path)?;
         let res = match candidates.pop() {
             None => bail!("no projects"),
             Some(it) => it,
@@ -87,23 +91,23 @@ impl ProjectRoot {
         Ok(res)
     }
 
-    pub fn discover(path: &Path) -> io::Result<Vec<ProjectRoot>> {
+    pub fn discover(path: &AbsPath) -> io::Result<Vec<ProjectManifest>> {
         if let Some(project_json) = find_in_parent_dirs(path, "rust-project.json") {
-            return Ok(vec![ProjectRoot::ProjectJson(project_json)]);
+            return Ok(vec![ProjectManifest::ProjectJson(project_json)]);
         }
         return find_cargo_toml(path)
-            .map(|paths| paths.into_iter().map(ProjectRoot::CargoToml).collect());
+            .map(|paths| paths.into_iter().map(ProjectManifest::CargoToml).collect());
 
-        fn find_cargo_toml(path: &Path) -> io::Result<Vec<PathBuf>> {
+        fn find_cargo_toml(path: &AbsPath) -> io::Result<Vec<AbsPathBuf>> {
             match find_in_parent_dirs(path, "Cargo.toml") {
                 Some(it) => Ok(vec![it]),
                 None => Ok(find_cargo_toml_in_child_dir(read_dir(path)?)),
             }
         }
 
-        fn find_in_parent_dirs(path: &Path, target_file_name: &str) -> Option<PathBuf> {
+        fn find_in_parent_dirs(path: &AbsPath, target_file_name: &str) -> Option<AbsPathBuf> {
             if path.ends_with(target_file_name) {
-                return Some(path.to_owned());
+                return Some(path.to_path_buf());
             }
 
             let mut curr = Some(path);
@@ -119,37 +123,50 @@ impl ProjectRoot {
             None
         }
 
-        fn find_cargo_toml_in_child_dir(entities: ReadDir) -> Vec<PathBuf> {
+        fn find_cargo_toml_in_child_dir(entities: ReadDir) -> Vec<AbsPathBuf> {
             // Only one level down to avoid cycles the easy way and stop a runaway scan with large projects
             entities
                 .filter_map(Result::ok)
                 .map(|it| it.path().join("Cargo.toml"))
                 .filter(|it| it.exists())
+                .map(AbsPathBuf::assert)
                 .collect()
         }
     }
+
+    pub fn discover_all(paths: &[impl AsRef<AbsPath>]) -> Vec<ProjectManifest> {
+        let mut res = paths
+            .iter()
+            .filter_map(|it| ProjectManifest::discover(it.as_ref()).ok())
+            .flatten()
+            .collect::<FxHashSet<_>>()
+            .into_iter()
+            .collect::<Vec<_>>();
+        res.sort();
+        res
+    }
 }
 
 impl ProjectWorkspace {
     pub fn load(
-        root: ProjectRoot,
-        cargo_features: &CargoConfig,
+        manifest: ProjectManifest,
+        cargo_config: &CargoConfig,
         with_sysroot: bool,
     ) -> Result<ProjectWorkspace> {
-        let res = match root {
-            ProjectRoot::ProjectJson(project_json) => {
-                let file = File::open(&project_json).with_context(|| {
-                    format!("Failed to open json file {}", project_json.display())
+        let res = match manifest {
+            ProjectManifest::ProjectJson(project_json) => {
+                let file = fs::read_to_string(&project_json).with_context(|| {
+                    format!("Failed to read json file {}", project_json.display())
                 })?;
-                let reader = BufReader::new(file);
-                ProjectWorkspace::Json {
-                    project: from_reader(reader).with_context(|| {
-                        format!("Failed to deserialize json file {}", project_json.display())
-                    })?,
-                }
+                let data = serde_json::from_str(&file).with_context(|| {
+                    format!("Failed to deserialize json file {}", project_json.display())
+                })?;
+                let project_location = project_json.parent().unwrap().to_path_buf();
+                let project = ProjectJson::new(&project_location, data);
+                ProjectWorkspace::Json { project }
             }
-            ProjectRoot::CargoToml(cargo_toml) => {
-                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_features)
+            ProjectManifest::CargoToml(cargo_toml) => {
+                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_config)
                     .with_context(|| {
                         format!(
                             "Failed to read Cargo metadata from Cargo.toml file {}",
@@ -186,6 +203,7 @@ impl ProjectWorkspace {
                 .map(|pkg| PackageRoot {
                     path: cargo[pkg].root().to_path_buf(),
                     is_member: cargo[pkg].is_member,
+                    out_dir: cargo[pkg].out_dir.clone(),
                 })
                 .chain(sysroot.crates().map(|krate| {
                     PackageRoot::new_non_member(sysroot[krate].root_dir().to_path_buf())
@@ -194,18 +212,7 @@ impl ProjectWorkspace {
         }
     }
 
-    pub fn out_dirs(&self) -> Vec<PathBuf> {
-        match self {
-            ProjectWorkspace::Json { project } => {
-                project.crates.iter().filter_map(|krate| krate.out_dir.as_ref()).cloned().collect()
-            }
-            ProjectWorkspace::Cargo { cargo, sysroot: _ } => {
-                cargo.packages().filter_map(|pkg| cargo[pkg].out_dir.as_ref()).cloned().collect()
-            }
-        }
-    }
-
-    pub fn proc_macro_dylib_paths(&self) -> Vec<PathBuf> {
+    pub fn proc_macro_dylib_paths(&self) -> Vec<AbsPathBuf> {
         match self {
             ProjectWorkspace::Json { project } => project
                 .crates
@@ -223,7 +230,7 @@ impl ProjectWorkspace {
 
     pub fn n_packages(&self) -> usize {
         match self {
-            ProjectWorkspace::Json { project } => project.crates.len(),
+            ProjectWorkspace::Json { project, .. } => project.crates.len(),
             ProjectWorkspace::Cargo { cargo, sysroot } => {
                 cargo.packages().len() + sysroot.crates().len()
             }
@@ -232,61 +239,51 @@ impl ProjectWorkspace {
 
     pub fn to_crate_graph(
         &self,
-        default_cfg_options: &CfgOptions,
-        extern_source_roots: &FxHashMap<PathBuf, ExternSourceId>,
+        target: Option<&str>,
         proc_macro_client: &ProcMacroClient,
-        load: &mut dyn FnMut(&Path) -> Option<FileId>,
+        load: &mut dyn FnMut(&AbsPath) -> Option<FileId>,
     ) -> CrateGraph {
         let mut crate_graph = CrateGraph::default();
         match self {
             ProjectWorkspace::Json { project } => {
+                let mut target_cfg_map = FxHashMap::<Option<&str>, CfgOptions>::default();
                 let crates: FxHashMap<_, _> = project
                     .crates
                     .iter()
                     .enumerate()
                     .filter_map(|(seq_index, krate)| {
-                        let file_id = load(&krate.root_module)?;
-                        let edition = match krate.edition {
-                            json_project::Edition::Edition2015 => Edition::Edition2015,
-                            json_project::Edition::Edition2018 => Edition::Edition2018,
-                        };
-                        let cfg_options = {
-                            let mut opts = default_cfg_options.clone();
-                            for name in &krate.atom_cfgs {
-                                opts.insert_atom(name.into());
-                            }
-                            for (key, value) in &krate.key_value_cfgs {
-                                opts.insert_key_value(key.into(), value.into());
-                            }
-                            opts
-                        };
+                        let file_path = &krate.root_module;
+                        let file_id = load(&file_path)?;
 
                         let mut env = Env::default();
-                        let mut extern_source = ExternSource::default();
                         if let Some(out_dir) = &krate.out_dir {
                             // NOTE: cargo and rustc seem to hide non-UTF-8 strings from env! and option_env!()
                             if let Some(out_dir) = out_dir.to_str().map(|s| s.to_owned()) {
                                 env.set("OUT_DIR", out_dir);
                             }
-                            if let Some(&extern_source_id) = extern_source_roots.get(out_dir) {
-                                extern_source.set_extern_path(&out_dir, extern_source_id);
-                            }
                         }
                         let proc_macro = krate
                             .proc_macro_dylib_path
                             .clone()
                             .map(|it| proc_macro_client.by_dylib_path(&it));
+
+                        let target = krate.target.as_deref().or(target);
+                        let target_cfgs = target_cfg_map
+                            .entry(target.clone())
+                            .or_insert_with(|| get_rustc_cfg_options(target.as_deref()));
+                        let mut cfg_options = krate.cfg.clone();
+                        cfg_options.append(target_cfgs);
+
                         // FIXME: No crate name in json definition such that we cannot add OUT_DIR to env
                         Some((
-                            json_project::CrateId(seq_index),
+                            CrateId(seq_index as u32),
                             crate_graph.add_crate_root(
                                 file_id,
-                                edition,
+                                krate.edition,
                                 // FIXME json definitions can store the crate name
                                 None,
                                 cfg_options,
                                 env,
-                                extern_source,
                                 proc_macro.unwrap_or_default(),
                             ),
                         ))
@@ -295,15 +292,12 @@ impl ProjectWorkspace {
 
                 for (id, krate) in project.crates.iter().enumerate() {
                     for dep in &krate.deps {
-                        let from_crate_id = json_project::CrateId(id);
-                        let to_crate_id = dep.krate;
+                        let from_crate_id = CrateId(id as u32);
+                        let to_crate_id = dep.crate_id;
                         if let (Some(&from), Some(&to)) =
                             (crates.get(&from_crate_id), crates.get(&to_crate_id))
                         {
-                            if crate_graph
-                                .add_dep(from, CrateName::new(&dep.name).unwrap(), to)
-                                .is_err()
-                            {
+                            if crate_graph.add_dep(from, dep.name.clone(), to).is_err() {
                                 log::error!(
                                     "cyclic dependency {:?} -> {:?}",
                                     from_crate_id,
@@ -315,31 +309,22 @@ impl ProjectWorkspace {
                 }
             }
             ProjectWorkspace::Cargo { cargo, sysroot } => {
+                let mut cfg_options = get_rustc_cfg_options(target);
+
                 let sysroot_crates: FxHashMap<_, _> = sysroot
                     .crates()
                     .filter_map(|krate| {
                         let file_id = load(&sysroot[krate].root)?;
 
-                        // Crates from sysroot have `cfg(test)` disabled
-                        let cfg_options = {
-                            let mut opts = default_cfg_options.clone();
-                            opts.remove_atom("test");
-                            opts
-                        };
-
                         let env = Env::default();
-                        let extern_source = ExternSource::default();
                         let proc_macro = vec![];
-                        let crate_name = CrateName::new(&sysroot[krate].name)
-                            .expect("Sysroot crate names should not contain dashes");
-
+                        let name = sysroot[krate].name.clone();
                         let crate_id = crate_graph.add_crate_root(
                             file_id,
                             Edition::Edition2018,
-                            Some(crate_name),
-                            cfg_options,
+                            Some(name),
+                            cfg_options.clone(),
                             env,
-                            extern_source,
                             proc_macro,
                         );
                         Some((krate, crate_id))
@@ -368,6 +353,10 @@ impl ProjectWorkspace {
 
                 let mut pkg_to_lib_crate = FxHashMap::default();
                 let mut pkg_crates = FxHashMap::default();
+
+                // Add test cfg for non-sysroot crates
+                cfg_options.insert_atom("test".into());
+
                 // Next, create crates for each package, target pair
                 for pkg in cargo.packages() {
                     let mut lib_tgt = None;
@@ -376,7 +365,7 @@ impl ProjectWorkspace {
                         if let Some(file_id) = load(root) {
                             let edition = cargo[pkg].edition;
                             let cfg_options = {
-                                let mut opts = default_cfg_options.clone();
+                                let mut opts = cfg_options.clone();
                                 for feature in cargo[pkg].features.iter() {
                                     opts.insert_key_value("feature".into(), feature.into());
                                 }
@@ -392,15 +381,11 @@ impl ProjectWorkspace {
                                 opts
                             };
                             let mut env = Env::default();
-                            let mut extern_source = ExternSource::default();
                             if let Some(out_dir) = &cargo[pkg].out_dir {
                                 // NOTE: cargo and rustc seem to hide non-UTF-8 strings from env! and option_env!()
                                 if let Some(out_dir) = out_dir.to_str().map(|s| s.to_owned()) {
                                     env.set("OUT_DIR", out_dir);
                                 }
-                                if let Some(&extern_source_id) = extern_source_roots.get(out_dir) {
-                                    extern_source.set_extern_path(&out_dir, extern_source_id);
-                                }
                             }
                             let proc_macro = cargo[pkg]
                                 .proc_macro_dylib_path
@@ -411,10 +396,9 @@ impl ProjectWorkspace {
                             let crate_id = crate_graph.add_crate_root(
                                 file_id,
                                 edition,
-                                Some(CrateName::normalize_dashes(&cargo[pkg].name)),
+                                Some(cargo[pkg].name.clone()),
                                 cfg_options,
                                 env,
-                                extern_source,
                                 proc_macro.clone(),
                             );
                             if cargo[tgt].kind == TargetKind::Lib {
@@ -520,20 +504,20 @@ impl ProjectWorkspace {
         crate_graph
     }
 
-    pub fn workspace_root_for(&self, path: &Path) -> Option<&Path> {
+    pub fn workspace_root_for(&self, path: &Path) -> Option<&AbsPath> {
         match self {
             ProjectWorkspace::Cargo { cargo, .. } => {
                 Some(cargo.workspace_root()).filter(|root| path.starts_with(root))
             }
-            ProjectWorkspace::Json { project: JsonProject { roots, .. } } => roots
+            ProjectWorkspace::Json { project: ProjectJson { roots, .. }, .. } => roots
                 .iter()
                 .find(|root| path.starts_with(&root.path))
-                .map(|root| root.path.as_ref()),
+                .map(|root| root.path.as_path()),
         }
     }
 }
 
-pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
+fn get_rustc_cfg_options(target: Option<&str>) -> CfgOptions {
     let mut cfg_options = CfgOptions::default();
 
     // Some nightly-only cfgs, which are required for stdlib
@@ -551,7 +535,7 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
         let mut cmd = Command::new(ra_toolchain::rustc());
         cmd.args(&["--print", "cfg", "-O"]);
         if let Some(target) = target {
-            cmd.args(&["--target", target.as_str()]);
+            cmd.args(&["--target", target]);
         }
         let output = output(cmd)?;
         Ok(String::from_utf8(output.stdout)?)
@@ -573,6 +557,8 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
         Err(e) => log::error!("failed to get rustc cfgs: {:#}", e),
     }
 
+    cfg_options.insert_atom("debug_assertions".into());
+
     cfg_options
 }
 
diff --git a/crates/ra_project_model/src/project_json.rs b/crates/ra_project_model/src/project_json.rs
new file mode 100644
index 000000000..b96227949
--- /dev/null
+++ b/crates/ra_project_model/src/project_json.rs
@@ -0,0 +1,129 @@
+//! FIXME: write short doc here
+
+use std::path::PathBuf;
+
+use paths::{AbsPath, AbsPathBuf};
+use ra_cfg::CfgOptions;
+use ra_db::{CrateId, CrateName, Dependency, Edition};
+use rustc_hash::FxHashSet;
+use serde::{de, Deserialize};
+use stdx::split_delim;
+
+/// Roots and crates that compose this Rust project.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ProjectJson {
+    pub(crate) roots: Vec<Root>,
+    pub(crate) crates: Vec<Crate>,
+}
+
+/// A root points to the directory which contains Rust crates. rust-analyzer watches all files in
+/// all roots. Roots might be nested.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Root {
+    pub(crate) path: AbsPathBuf,
+}
+
+/// A crate points to the root module of a crate and lists the dependencies of the crate. This is
+/// useful in creating the crate graph.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Crate {
+    pub(crate) root_module: AbsPathBuf,
+    pub(crate) edition: Edition,
+    pub(crate) deps: Vec<Dependency>,
+    pub(crate) cfg: CfgOptions,
+    pub(crate) target: Option<String>,
+    pub(crate) out_dir: Option<AbsPathBuf>,
+    pub(crate) proc_macro_dylib_path: Option<AbsPathBuf>,
+}
+
+impl ProjectJson {
+    pub fn new(base: &AbsPath, data: ProjectJsonData) -> ProjectJson {
+        ProjectJson {
+            roots: data.roots.into_iter().map(|path| Root { path: base.join(path) }).collect(),
+            crates: data
+                .crates
+                .into_iter()
+                .map(|crate_data| Crate {
+                    root_module: base.join(crate_data.root_module),
+                    edition: crate_data.edition.into(),
+                    deps: crate_data
+                        .deps
+                        .into_iter()
+                        .map(|dep_data| Dependency {
+                            crate_id: CrateId(dep_data.krate as u32),
+                            name: dep_data.name,
+                        })
+                        .collect::<Vec<_>>(),
+                    cfg: {
+                        let mut cfg = CfgOptions::default();
+                        for entry in &crate_data.cfg {
+                            match split_delim(entry, '=') {
+                                Some((key, value)) => {
+                                    cfg.insert_key_value(key.into(), value.into());
+                                }
+                                None => cfg.insert_atom(entry.into()),
+                            }
+                        }
+                        cfg
+                    },
+                    target: crate_data.target,
+                    out_dir: crate_data.out_dir.map(|it| base.join(it)),
+                    proc_macro_dylib_path: crate_data.proc_macro_dylib_path.map(|it| base.join(it)),
+                })
+                .collect::<Vec<_>>(),
+        }
+    }
+}
+
+#[derive(Deserialize)]
+pub struct ProjectJsonData {
+    roots: Vec<PathBuf>,
+    crates: Vec<CrateData>,
+}
+
+#[derive(Deserialize)]
+struct CrateData {
+    root_module: PathBuf,
+    edition: EditionData,
+    deps: Vec<DepData>,
+    #[serde(default)]
+    cfg: FxHashSet<String>,
+    target: Option<String>,
+    out_dir: Option<PathBuf>,
+    proc_macro_dylib_path: Option<PathBuf>,
+}
+
+#[derive(Deserialize)]
+#[serde(rename = "edition")]
+enum EditionData {
+    #[serde(rename = "2015")]
+    Edition2015,
+    #[serde(rename = "2018")]
+    Edition2018,
+}
+
+impl From<EditionData> for Edition {
+    fn from(data: EditionData) -> Self {
+        match data {
+            EditionData::Edition2015 => Edition::Edition2015,
+            EditionData::Edition2018 => Edition::Edition2018,
+        }
+    }
+}
+
+#[derive(Deserialize)]
+struct DepData {
+    /// Identifies a crate by position in the crates array.
+    #[serde(rename = "crate")]
+    krate: usize,
+    #[serde(deserialize_with = "deserialize_crate_name")]
+    name: CrateName,
+}
+
+fn deserialize_crate_name<'de, D>(de: D) -> Result<CrateName, D::Error>
+where
+    D: de::Deserializer<'de>,
+{
+    let name = String::deserialize(de)?;
+    CrateName::new(&name).map_err(|err| de::Error::custom(format!("invalid crate name: {:?}", err)))
+}
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index a8a196e64..68d134da4 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -1,27 +1,24 @@
 //! FIXME: write short doc here
 
-use std::{
-    env, ops,
-    path::{Path, PathBuf},
-    process::Command,
-};
+use std::{convert::TryFrom, env, ops, path::Path, process::Command};
 
-use anyhow::{bail, Result};
+use anyhow::{bail, format_err, Result};
+use paths::{AbsPath, AbsPathBuf};
 use ra_arena::{Arena, Idx};
 
 use crate::output;
 
-#[derive(Default, Debug, Clone)]
+#[derive(Default, Debug, Clone, Eq, PartialEq)]
 pub struct Sysroot {
     crates: Arena<SysrootCrateData>,
 }
 
 pub type SysrootCrate = Idx<SysrootCrateData>;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct SysrootCrateData {
     pub name: String,
-    pub root: PathBuf,
+    pub root: AbsPathBuf,
     pub deps: Vec<SysrootCrate>,
 }
 
@@ -53,7 +50,7 @@ impl Sysroot {
         self.crates.iter().map(|(id, _data)| id)
     }
 
-    pub fn discover(cargo_toml: &Path) -> Result<Sysroot> {
+    pub fn discover(cargo_toml: &AbsPath) -> Result<Sysroot> {
         let src = get_or_install_rust_src(cargo_toml)?;
         let mut sysroot = Sysroot { crates: Arena::default() };
         for name in SYSROOT_CRATES.trim().lines() {
@@ -86,16 +83,18 @@ impl Sysroot {
     }
 }
 
-fn get_or_install_rust_src(cargo_toml: &Path) -> Result<PathBuf> {
+fn get_or_install_rust_src(cargo_toml: &AbsPath) -> Result<AbsPathBuf> {
     if let Ok(path) = env::var("RUST_SRC_PATH") {
-        return Ok(path.into());
+        let path = AbsPathBuf::try_from(path.as_str())
+            .map_err(|path| format_err!("RUST_SRC_PATH must be absolute: {}", path.display()))?;
+        return Ok(path);
     }
     let current_dir = cargo_toml.parent().unwrap();
     let mut rustc = Command::new(ra_toolchain::rustc());
     rustc.current_dir(current_dir).args(&["--print", "sysroot"]);
     let rustc_output = output(rustc)?;
     let stdout = String::from_utf8(rustc_output.stdout)?;
-    let sysroot_path = Path::new(stdout.trim());
+    let sysroot_path = AbsPath::assert(Path::new(stdout.trim()));
     let src_path = sysroot_path.join("lib/rustlib/src/rust/src");
 
     if !src_path.exists() {
@@ -116,7 +115,7 @@ fn get_or_install_rust_src(cargo_toml: &Path) -> Result<PathBuf> {
 }
 
 impl SysrootCrateData {
-    pub fn root_dir(&self) -> &Path {
+    pub fn root_dir(&self) -> &AbsPath {
         self.root.parent().unwrap()
     }
 }
@@ -127,7 +126,6 @@ core
 alloc
 collections
 libc
-panic_unwind
 proc_macro
 rustc_unicode
 std_unicode
diff --git a/crates/ra_ssr/Cargo.toml b/crates/ra_ssr/Cargo.toml
new file mode 100644
index 000000000..fe098aaee
--- /dev/null
+++ b/crates/ra_ssr/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+edition = "2018"
+name = "ra_ssr"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
+description = "Structural search and replace of Rust code"
+repository = "https://github.com/rust-analyzer/rust-analyzer"
+
+[lib]
+doctest = false
+
+[dependencies]
+ra_text_edit = { path = "../ra_text_edit" }
+ra_syntax = { path = "../ra_syntax" }
+ra_db = { path = "../ra_db" }
+ra_ide_db = { path = "../ra_ide_db" }
+hir = { path = "../ra_hir", package = "ra_hir" }
+rustc-hash = "1.1.0"
+test_utils = { path = "../test_utils" }
diff --git a/crates/ra_ssr/src/errors.rs b/crates/ra_ssr/src/errors.rs
new file mode 100644
index 000000000..c02bacae6
--- /dev/null
+++ b/crates/ra_ssr/src/errors.rs
@@ -0,0 +1,29 @@
+//! Code relating to errors produced by SSR.
+
+/// Constructs an SsrError taking arguments like the format macro.
+macro_rules! _error {
+    ($fmt:expr) => {$crate::SsrError::new(format!($fmt))};
+    ($fmt:expr, $($arg:tt)+) => {$crate::SsrError::new(format!($fmt, $($arg)+))}
+}
+pub(crate) use _error as error;
+
+/// Returns from the current function with an error, supplied by arguments as for format!
+macro_rules! _bail {
+    ($($tokens:tt)*) => {return Err(crate::errors::error!($($tokens)*))}
+}
+pub(crate) use _bail as bail;
+
+#[derive(Debug, PartialEq)]
+pub struct SsrError(pub(crate) String);
+
+impl std::fmt::Display for SsrError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "Parse error: {}", self.0)
+    }
+}
+
+impl SsrError {
+    pub(crate) fn new(message: impl Into<String>) -> SsrError {
+        SsrError(message.into())
+    }
+}
diff --git a/crates/ra_ssr/src/lib.rs b/crates/ra_ssr/src/lib.rs
new file mode 100644
index 000000000..cca4576ce
--- /dev/null
+++ b/crates/ra_ssr/src/lib.rs
@@ -0,0 +1,285 @@
+//! Structural Search Replace
+//!
+//! Allows searching the AST for code that matches one or more patterns and then replacing that code
+//! based on a template.
+
+mod matching;
+mod parsing;
+mod replacing;
+#[macro_use]
+mod errors;
+#[cfg(test)]
+mod tests;
+
+pub use crate::errors::SsrError;
+pub use crate::matching::Match;
+use crate::matching::{record_match_fails_reasons_scope, MatchFailureReason};
+use hir::Semantics;
+use ra_db::{FileId, FileRange};
+use ra_syntax::{ast, AstNode, SmolStr, SyntaxKind, SyntaxNode, TextRange};
+use ra_text_edit::TextEdit;
+use rustc_hash::FxHashMap;
+
+// A structured search replace rule. Create by calling `parse` on a str.
+#[derive(Debug)]
+pub struct SsrRule {
+    /// A structured pattern that we're searching for.
+    pattern: SsrPattern,
+    /// What we'll replace it with.
+    template: parsing::SsrTemplate,
+}
+
+#[derive(Debug)]
+pub struct SsrPattern {
+    raw: parsing::RawSearchPattern,
+    /// Placeholders keyed by the stand-in ident that we use in Rust source code.
+    placeholders_by_stand_in: FxHashMap<SmolStr, parsing::Placeholder>,
+    // We store our search pattern, parsed as each different kind of thing we can look for. As we
+    // traverse the AST, we get the appropriate one of these for the type of node we're on. For many
+    // search patterns, only some of these will be present.
+    expr: Option<SyntaxNode>,
+    type_ref: Option<SyntaxNode>,
+    item: Option<SyntaxNode>,
+    path: Option<SyntaxNode>,
+    pattern: Option<SyntaxNode>,
+}
+
+#[derive(Debug, Default)]
+pub struct SsrMatches {
+    pub matches: Vec<Match>,
+}
+
+/// Searches a crate for pattern matches and possibly replaces them with something else.
+pub struct MatchFinder<'db> {
+    /// Our source of information about the user's code.
+    sema: Semantics<'db, ra_ide_db::RootDatabase>,
+    rules: Vec<SsrRule>,
+}
+
+impl<'db> MatchFinder<'db> {
+    pub fn new(db: &'db ra_ide_db::RootDatabase) -> MatchFinder<'db> {
+        MatchFinder { sema: Semantics::new(db), rules: Vec::new() }
+    }
+
+    pub fn add_rule(&mut self, rule: SsrRule) {
+        self.rules.push(rule);
+    }
+
+    /// Adds a search pattern. For use if you intend to only call `find_matches_in_file`. If you
+    /// intend to do replacement, use `add_rule` instead.
+    pub fn add_search_pattern(&mut self, pattern: SsrPattern) {
+        self.add_rule(SsrRule { pattern, template: "()".parse().unwrap() })
+    }
+
+    pub fn edits_for_file(&self, file_id: FileId) -> Option<TextEdit> {
+        let matches = self.find_matches_in_file(file_id);
+        if matches.matches.is_empty() {
+            None
+        } else {
+            use ra_db::SourceDatabaseExt;
+            Some(replacing::matches_to_edit(&matches, &self.sema.db.file_text(file_id)))
+        }
+    }
+
+    pub fn find_matches_in_file(&self, file_id: FileId) -> SsrMatches {
+        let file = self.sema.parse(file_id);
+        let code = file.syntax();
+        let mut matches = SsrMatches::default();
+        self.find_matches(code, &None, &mut matches);
+        matches
+    }
+
+    /// Finds all nodes in `file_id` whose text is exactly equal to `snippet` and attempts to match
+    /// them, while recording reasons why they don't match. This API is useful for command
+    /// line-based debugging where providing a range is difficult.
+    pub fn debug_where_text_equal(&self, file_id: FileId, snippet: &str) -> Vec<MatchDebugInfo> {
+        use ra_db::SourceDatabaseExt;
+        let file = self.sema.parse(file_id);
+        let mut res = Vec::new();
+        let file_text = self.sema.db.file_text(file_id);
+        let mut remaining_text = file_text.as_str();
+        let mut base = 0;
+        let len = snippet.len() as u32;
+        while let Some(offset) = remaining_text.find(snippet) {
+            let start = base + offset as u32;
+            let end = start + len;
+            self.output_debug_for_nodes_at_range(
+                file.syntax(),
+                FileRange { file_id, range: TextRange::new(start.into(), end.into()) },
+                &None,
+                &mut res,
+            );
+            remaining_text = &remaining_text[offset + snippet.len()..];
+            base = end;
+        }
+        res
+    }
+
+    fn find_matches(
+        &self,
+        code: &SyntaxNode,
+        restrict_range: &Option<FileRange>,
+        matches_out: &mut SsrMatches,
+    ) {
+        for rule in &self.rules {
+            if let Ok(mut m) = matching::get_match(false, rule, &code, restrict_range, &self.sema) {
+                // Continue searching in each of our placeholders.
+                for placeholder_value in m.placeholder_values.values_mut() {
+                    if let Some(placeholder_node) = &placeholder_value.node {
+                        // Don't search our placeholder if it's the entire matched node, otherwise we'd
+                        // find the same match over and over until we got a stack overflow.
+                        if placeholder_node != code {
+                            self.find_matches(
+                                placeholder_node,
+                                restrict_range,
+                                &mut placeholder_value.inner_matches,
+                            );
+                        }
+                    }
+                }
+                matches_out.matches.push(m);
+                return;
+            }
+        }
+        // If we've got a macro call, we already tried matching it pre-expansion, which is the only
+        // way to match the whole macro, now try expanding it and matching the expansion.
+        if let Some(macro_call) = ast::MacroCall::cast(code.clone()) {
+            if let Some(expanded) = self.sema.expand(&macro_call) {
+                if let Some(tt) = macro_call.token_tree() {
+                    // When matching within a macro expansion, we only want to allow matches of
+                    // nodes that originated entirely from within the token tree of the macro call.
+                    // i.e. we don't want to match something that came from the macro itself.
+                    self.find_matches(
+                        &expanded,
+                        &Some(self.sema.original_range(tt.syntax())),
+                        matches_out,
+                    );
+                }
+            }
+        }
+        for child in code.children() {
+            self.find_matches(&child, restrict_range, matches_out);
+        }
+    }
+
+    fn output_debug_for_nodes_at_range(
+        &self,
+        node: &SyntaxNode,
+        range: FileRange,
+        restrict_range: &Option<FileRange>,
+        out: &mut Vec<MatchDebugInfo>,
+    ) {
+        for node in node.children() {
+            let node_range = self.sema.original_range(&node);
+            if node_range.file_id != range.file_id || !node_range.range.contains_range(range.range)
+            {
+                continue;
+            }
+            if node_range.range == range.range {
+                for rule in &self.rules {
+                    let pattern =
+                        rule.pattern.tree_for_kind_with_reason(node.kind()).map(|p| p.clone());
+                    out.push(MatchDebugInfo {
+                        matched: matching::get_match(true, rule, &node, restrict_range, &self.sema)
+                            .map_err(|e| MatchFailureReason {
+                                reason: e.reason.unwrap_or_else(|| {
+                                    "Match failed, but no reason was given".to_owned()
+                                }),
+                            }),
+                        pattern,
+                        node: node.clone(),
+                    });
+                }
+            } else if let Some(macro_call) = ast::MacroCall::cast(node.clone()) {
+                if let Some(expanded) = self.sema.expand(&macro_call) {
+                    if let Some(tt) = macro_call.token_tree() {
+                        self.output_debug_for_nodes_at_range(
+                            &expanded,
+                            range,
+                            &Some(self.sema.original_range(tt.syntax())),
+                            out,
+                        );
+                    }
+                }
+            }
+            self.output_debug_for_nodes_at_range(&node, range, restrict_range, out);
+        }
+    }
+}
+
+pub struct MatchDebugInfo {
+    node: SyntaxNode,
+    /// Our search pattern parsed as the same kind of syntax node as `node`. e.g. expression, item,
+    /// etc. Will be absent if the pattern can't be parsed as that kind.
+    pattern: Result<SyntaxNode, MatchFailureReason>,
+    matched: Result<Match, MatchFailureReason>,
+}
+
+impl std::fmt::Debug for MatchDebugInfo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match &self.matched {
+            Ok(_) => writeln!(f, "Node matched")?,
+            Err(reason) => writeln!(f, "Node failed to match because: {}", reason.reason)?,
+        }
+        writeln!(
+            f,
+            "============ AST ===========\n\
+            {:#?}",
+            self.node
+        )?;
+        writeln!(f, "========= PATTERN ==========")?;
+        match &self.pattern {
+            Ok(pattern) => {
+                writeln!(f, "{:#?}", pattern)?;
+            }
+            Err(err) => {
+                writeln!(f, "{}", err.reason)?;
+            }
+        }
+        writeln!(f, "============================")?;
+        Ok(())
+    }
+}
+
+impl SsrPattern {
+    fn tree_for_kind_with_reason(
+        &self,
+        kind: SyntaxKind,
+    ) -> Result<&SyntaxNode, MatchFailureReason> {
+        record_match_fails_reasons_scope(true, || self.tree_for_kind(kind))
+            .map_err(|e| MatchFailureReason { reason: e.reason.unwrap() })
+    }
+}
+
+impl SsrMatches {
+    /// Returns `self` with any nested matches removed and made into top-level matches.
+    pub fn flattened(self) -> SsrMatches {
+        let mut out = SsrMatches::default();
+        self.flatten_into(&mut out);
+        out
+    }
+
+    fn flatten_into(self, out: &mut SsrMatches) {
+        for mut m in self.matches {
+            for p in m.placeholder_values.values_mut() {
+                std::mem::replace(&mut p.inner_matches, SsrMatches::default()).flatten_into(out);
+            }
+            out.matches.push(m);
+        }
+    }
+}
+
+impl Match {
+    pub fn matched_text(&self) -> String {
+        self.matched_node.text().to_string()
+    }
+}
+
+impl std::error::Error for SsrError {}
+
+#[cfg(test)]
+impl MatchDebugInfo {
+    pub(crate) fn match_failure_reason(&self) -> Option<&str> {
+        self.matched.as_ref().err().map(|r| r.reason.as_str())
+    }
+}
diff --git a/crates/ra_ssr/src/matching.rs b/crates/ra_ssr/src/matching.rs
new file mode 100644
index 000000000..50b29eab2
--- /dev/null
+++ b/crates/ra_ssr/src/matching.rs
@@ -0,0 +1,623 @@
+//! This module is responsible for matching a search pattern against a node in the AST. In the
+//! process of matching, placeholder values are recorded.
+
+use crate::{
+    parsing::{Constraint, NodeKind, Placeholder, SsrTemplate},
+    SsrMatches, SsrPattern, SsrRule,
+};
+use hir::Semantics;
+use ra_db::FileRange;
+use ra_syntax::ast::{AstNode, AstToken};
+use ra_syntax::{ast, SyntaxElement, SyntaxElementChildren, SyntaxKind, SyntaxNode, SyntaxToken};
+use rustc_hash::FxHashMap;
+use std::{cell::Cell, iter::Peekable};
+use test_utils::mark;
+
+// Creates a match error. If we're currently attempting to match some code that we thought we were
+// going to match, as indicated by the --debug-snippet flag, then populate the reason field.
+macro_rules! match_error {
+    ($e:expr) => {{
+            MatchFailed {
+                reason: if recording_match_fail_reasons() {
+                    Some(format!("{}", $e))
+                } else {
+                    None
+                }
+            }
+    }};
+    ($fmt:expr, $($arg:tt)+) => {{
+        MatchFailed {
+            reason: if recording_match_fail_reasons() {
+                Some(format!($fmt, $($arg)+))
+            } else {
+                None
+            }
+        }
+    }};
+}
+
+// Fails the current match attempt, recording the supplied reason if we're recording match fail reasons.
+macro_rules! fail_match {
+    ($($args:tt)*) => {return Err(match_error!($($args)*))};
+}
+
+/// Information about a match that was found.
+#[derive(Debug)]
+pub struct Match {
+    pub(crate) range: FileRange,
+    pub(crate) matched_node: SyntaxNode,
+    pub(crate) placeholder_values: FxHashMap<Var, PlaceholderMatch>,
+    pub(crate) ignored_comments: Vec<ast::Comment>,
+    // A copy of the template for the rule that produced this match. We store this on the match for
+    // if/when we do replacement.
+    pub(crate) template: SsrTemplate,
+}
+
+/// Represents a `$var` in an SSR query.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub(crate) struct Var(pub String);
+
+/// Information about a placeholder bound in a match.
+#[derive(Debug)]
+pub(crate) struct PlaceholderMatch {
+    /// The node that the placeholder matched to. If set, then we'll search for further matches
+    /// within this node. It isn't set when we match tokens within a macro call's token tree.
+    pub(crate) node: Option<SyntaxNode>,
+    pub(crate) range: FileRange,
+    /// More matches, found within `node`.
+    pub(crate) inner_matches: SsrMatches,
+}
+
+#[derive(Debug)]
+pub(crate) struct MatchFailureReason {
+    pub(crate) reason: String,
+}
+
+/// An "error" indicating that matching failed. Use the fail_match! macro to create and return this.
+#[derive(Clone)]
+pub(crate) struct MatchFailed {
+    /// The reason why we failed to match. Only present when debug_active true in call to
+    /// `get_match`.
+    pub(crate) reason: Option<String>,
+}
+
+/// Checks if `code` matches the search pattern found in `search_scope`, returning information about
+/// the match, if it does. Since we only do matching in this module and searching is done by the
+/// parent module, we don't populate nested matches.
+pub(crate) fn get_match(
+    debug_active: bool,
+    rule: &SsrRule,
+    code: &SyntaxNode,
+    restrict_range: &Option<FileRange>,
+    sema: &Semantics<ra_ide_db::RootDatabase>,
+) -> Result<Match, MatchFailed> {
+    record_match_fails_reasons_scope(debug_active, || {
+        Matcher::try_match(rule, code, restrict_range, sema)
+    })
+}
+
+/// Checks if our search pattern matches a particular node of the AST.
+struct Matcher<'db, 'sema> {
+    sema: &'sema Semantics<'db, ra_ide_db::RootDatabase>,
+    /// If any placeholders come from anywhere outside of this range, then the match will be
+    /// rejected.
+    restrict_range: Option<FileRange>,
+    rule: &'sema SsrRule,
+}
+
+/// Which phase of matching we're currently performing. We do two phases because most attempted
+/// matches will fail and it means we can defer more expensive checks to the second phase.
+enum Phase<'a> {
+    /// On the first phase, we perform cheap checks. No state is mutated and nothing is recorded.
+    First,
+    /// On the second phase, we construct the `Match`. Things like what placeholders bind to is
+    /// recorded.
+    Second(&'a mut Match),
+}
+
+impl<'db, 'sema> Matcher<'db, 'sema> {
+    fn try_match(
+        rule: &'sema SsrRule,
+        code: &SyntaxNode,
+        restrict_range: &Option<FileRange>,
+        sema: &'sema Semantics<'db, ra_ide_db::RootDatabase>,
+    ) -> Result<Match, MatchFailed> {
+        let match_state = Matcher { sema, restrict_range: restrict_range.clone(), rule };
+        let pattern_tree = rule.pattern.tree_for_kind(code.kind())?;
+        // First pass at matching, where we check that node types and idents match.
+        match_state.attempt_match_node(&mut Phase::First, &pattern_tree, code)?;
+        match_state.validate_range(&sema.original_range(code))?;
+        let mut the_match = Match {
+            range: sema.original_range(code),
+            matched_node: code.clone(),
+            placeholder_values: FxHashMap::default(),
+            ignored_comments: Vec::new(),
+            template: rule.template.clone(),
+        };
+        // Second matching pass, where we record placeholder matches, ignored comments and maybe do
+        // any other more expensive checks that we didn't want to do on the first pass.
+        match_state.attempt_match_node(&mut Phase::Second(&mut the_match), &pattern_tree, code)?;
+        Ok(the_match)
+    }
+
+    /// Checks that `range` is within the permitted range if any. This is applicable when we're
+    /// processing a macro expansion and we want to fail the match if we're working with a node that
+    /// didn't originate from the token tree of the macro call.
+    fn validate_range(&self, range: &FileRange) -> Result<(), MatchFailed> {
+        if let Some(restrict_range) = &self.restrict_range {
+            if restrict_range.file_id != range.file_id
+                || !restrict_range.range.contains_range(range.range)
+            {
+                fail_match!("Node originated from a macro");
+            }
+        }
+        Ok(())
+    }
+
+    fn attempt_match_node(
+        &self,
+        phase: &mut Phase,
+        pattern: &SyntaxNode,
+        code: &SyntaxNode,
+    ) -> Result<(), MatchFailed> {
+        // Handle placeholders.
+        if let Some(placeholder) = self.get_placeholder(&SyntaxElement::Node(pattern.clone())) {
+            for constraint in &placeholder.constraints {
+                self.check_constraint(constraint, code)?;
+            }
+            if let Phase::Second(matches_out) = phase {
+                let original_range = self.sema.original_range(code);
+                // We validated the range for the node when we started the match, so the placeholder
+                // probably can't fail range validation, but just to be safe...
+                self.validate_range(&original_range)?;
+                matches_out.placeholder_values.insert(
+                    Var(placeholder.ident.to_string()),
+                    PlaceholderMatch::new(code, original_range),
+                );
+            }
+            return Ok(());
+        }
+        // Non-placeholders.
+        if pattern.kind() != code.kind() {
+            fail_match!(
+                "Pattern had a `{}` ({:?}), code had `{}` ({:?})",
+                pattern.text(),
+                pattern.kind(),
+                code.text(),
+                code.kind()
+            );
+        }
+        // Some kinds of nodes have special handling. For everything else, we fall back to default
+        // matching.
+        match code.kind() {
+            SyntaxKind::RECORD_FIELD_LIST => {
+                self.attempt_match_record_field_list(phase, pattern, code)
+            }
+            SyntaxKind::TOKEN_TREE => self.attempt_match_token_tree(phase, pattern, code),
+            _ => self.attempt_match_node_children(phase, pattern, code),
+        }
+    }
+
+    fn attempt_match_node_children(
+        &self,
+        phase: &mut Phase,
+        pattern: &SyntaxNode,
+        code: &SyntaxNode,
+    ) -> Result<(), MatchFailed> {
+        self.attempt_match_sequences(
+            phase,
+            PatternIterator::new(pattern),
+            code.children_with_tokens(),
+        )
+    }
+
+    fn attempt_match_sequences(
+        &self,
+        phase: &mut Phase,
+        pattern_it: PatternIterator,
+        mut code_it: SyntaxElementChildren,
+    ) -> Result<(), MatchFailed> {
+        let mut pattern_it = pattern_it.peekable();
+        loop {
+            match phase.next_non_trivial(&mut code_it) {
+                None => {
+                    if let Some(p) = pattern_it.next() {
+                        fail_match!("Part of the pattern was unmatched: {:?}", p);
+                    }
+                    return Ok(());
+                }
+                Some(SyntaxElement::Token(c)) => {
+                    self.attempt_match_token(phase, &mut pattern_it, &c)?;
+                }
+                Some(SyntaxElement::Node(c)) => match pattern_it.next() {
+                    Some(SyntaxElement::Node(p)) => {
+                        self.attempt_match_node(phase, &p, &c)?;
+                    }
+                    Some(p) => fail_match!("Pattern wanted '{}', code has {}", p, c.text()),
+                    None => fail_match!("Pattern reached end, code has {}", c.text()),
+                },
+            }
+        }
+    }
+
+    fn attempt_match_token(
+        &self,
+        phase: &mut Phase,
+        pattern: &mut Peekable<PatternIterator>,
+        code: &ra_syntax::SyntaxToken,
+    ) -> Result<(), MatchFailed> {
+        phase.record_ignored_comments(code);
+        // Ignore whitespace and comments.
+        if code.kind().is_trivia() {
+            return Ok(());
+        }
+        if let Some(SyntaxElement::Token(p)) = pattern.peek() {
+            // If the code has a comma and the pattern is about to close something, then accept the
+            // comma without advancing the pattern. i.e. ignore trailing commas.
+            if code.kind() == SyntaxKind::COMMA && is_closing_token(p.kind()) {
+                return Ok(());
+            }
+            // Conversely, if the pattern has a comma and the code doesn't, skip that part of the
+            // pattern and continue to match the code.
+            if p.kind() == SyntaxKind::COMMA && is_closing_token(code.kind()) {
+                pattern.next();
+            }
+        }
+        // Consume an element from the pattern and make sure it matches.
+        match pattern.next() {
+            Some(SyntaxElement::Token(p)) => {
+                if p.kind() != code.kind() || p.text() != code.text() {
+                    fail_match!(
+                        "Pattern wanted token '{}' ({:?}), but code had token '{}' ({:?})",
+                        p.text(),
+                        p.kind(),
+                        code.text(),
+                        code.kind()
+                    )
+                }
+            }
+            Some(SyntaxElement::Node(p)) => {
+                // Not sure if this is actually reachable.
+                fail_match!(
+                    "Pattern wanted {:?}, but code had token '{}' ({:?})",
+                    p,
+                    code.text(),
+                    code.kind()
+                );
+            }
+            None => {
+                fail_match!("Pattern exhausted, while code remains: `{}`", code.text());
+            }
+        }
+        Ok(())
+    }
+
+    fn check_constraint(
+        &self,
+        constraint: &Constraint,
+        code: &SyntaxNode,
+    ) -> Result<(), MatchFailed> {
+        match constraint {
+            Constraint::Kind(kind) => {
+                kind.matches(code)?;
+            }
+            Constraint::Not(sub) => {
+                if self.check_constraint(&*sub, code).is_ok() {
+                    fail_match!("Constraint {:?} failed for '{}'", constraint, code.text());
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// We want to allow the records to match in any order, so we have special matching logic for
+    /// them.
+    fn attempt_match_record_field_list(
+        &self,
+        phase: &mut Phase,
+        pattern: &SyntaxNode,
+        code: &SyntaxNode,
+    ) -> Result<(), MatchFailed> {
+        // Build a map keyed by field name.
+        let mut fields_by_name = FxHashMap::default();
+        for child in code.children() {
+            if let Some(record) = ast::RecordField::cast(child.clone()) {
+                if let Some(name) = record.field_name() {
+                    fields_by_name.insert(name.text().clone(), child.clone());
+                }
+            }
+        }
+        for p in pattern.children_with_tokens() {
+            if let SyntaxElement::Node(p) = p {
+                if let Some(name_element) = p.first_child_or_token() {
+                    if self.get_placeholder(&name_element).is_some() {
+                        // If the pattern is using placeholders for field names then order
+                        // independence doesn't make sense. Fall back to regular ordered
+                        // matching.
+                        return self.attempt_match_node_children(phase, pattern, code);
+                    }
+                    if let Some(ident) = only_ident(name_element) {
+                        let code_record = fields_by_name.remove(ident.text()).ok_or_else(|| {
+                            match_error!(
+                                "Placeholder has record field '{}', but code doesn't",
+                                ident
+                            )
+                        })?;
+                        self.attempt_match_node(phase, &p, &code_record)?;
+                    }
+                }
+            }
+        }
+        if let Some(unmatched_fields) = fields_by_name.keys().next() {
+            fail_match!(
+                "{} field(s) of a record literal failed to match, starting with {}",
+                fields_by_name.len(),
+                unmatched_fields
+            );
+        }
+        Ok(())
+    }
+
+    /// Outside of token trees, a placeholder can only match a single AST node, whereas in a token
+    /// tree it can match a sequence of tokens. Note, that this code will only be used when the
+    /// pattern matches the macro invocation. For matches within the macro call, we'll already have
+    /// expanded the macro.
+    fn attempt_match_token_tree(
+        &self,
+        phase: &mut Phase,
+        pattern: &SyntaxNode,
+        code: &ra_syntax::SyntaxNode,
+    ) -> Result<(), MatchFailed> {
+        let mut pattern = PatternIterator::new(pattern).peekable();
+        let mut children = code.children_with_tokens();
+        while let Some(child) = children.next() {
+            if let Some(placeholder) = pattern.peek().and_then(|p| self.get_placeholder(p)) {
+                pattern.next();
+                let next_pattern_token = pattern
+                    .peek()
+                    .and_then(|p| match p {
+                        SyntaxElement::Token(t) => Some(t.clone()),
+                        SyntaxElement::Node(n) => n.first_token(),
+                    })
+                    .map(|p| p.text().to_string());
+                let first_matched_token = child.clone();
+                let mut last_matched_token = child;
+                // Read code tokens util we reach one equal to the next token from our pattern
+                // or we reach the end of the token tree.
+                while let Some(next) = children.next() {
+                    match &next {
+                        SyntaxElement::Token(t) => {
+                            if Some(t.to_string()) == next_pattern_token {
+                                pattern.next();
+                                break;
+                            }
+                        }
+                        SyntaxElement::Node(n) => {
+                            if let Some(first_token) = n.first_token() {
+                                if Some(first_token.to_string()) == next_pattern_token {
+                                    if let Some(SyntaxElement::Node(p)) = pattern.next() {
+                                        // We have a subtree that starts with the next token in our pattern.
+                                        self.attempt_match_token_tree(phase, &p, &n)?;
+                                        break;
+                                    }
+                                }
+                            }
+                        }
+                    };
+                    last_matched_token = next;
+                }
+                if let Phase::Second(match_out) = phase {
+                    match_out.placeholder_values.insert(
+                        Var(placeholder.ident.to_string()),
+                        PlaceholderMatch::from_range(FileRange {
+                            file_id: self.sema.original_range(code).file_id,
+                            range: first_matched_token
+                                .text_range()
+                                .cover(last_matched_token.text_range()),
+                        }),
+                    );
+                }
+                continue;
+            }
+            // Match literal (non-placeholder) tokens.
+            match child {
+                SyntaxElement::Token(token) => {
+                    self.attempt_match_token(phase, &mut pattern, &token)?;
+                }
+                SyntaxElement::Node(node) => match pattern.next() {
+                    Some(SyntaxElement::Node(p)) => {
+                        self.attempt_match_token_tree(phase, &p, &node)?;
+                    }
+                    Some(SyntaxElement::Token(p)) => fail_match!(
+                        "Pattern has token '{}', code has subtree '{}'",
+                        p.text(),
+                        node.text()
+                    ),
+                    None => fail_match!("Pattern has nothing, code has '{}'", node.text()),
+                },
+            }
+        }
+        if let Some(p) = pattern.next() {
+            fail_match!("Reached end of token tree in code, but pattern still has {:?}", p);
+        }
+        Ok(())
+    }
+
+    fn get_placeholder(&self, element: &SyntaxElement) -> Option<&Placeholder> {
+        only_ident(element.clone())
+            .and_then(|ident| self.rule.pattern.placeholders_by_stand_in.get(ident.text()))
+    }
+}
+
+impl Phase<'_> {
+    fn next_non_trivial(&mut self, code_it: &mut SyntaxElementChildren) -> Option<SyntaxElement> {
+        loop {
+            let c = code_it.next();
+            if let Some(SyntaxElement::Token(t)) = &c {
+                self.record_ignored_comments(t);
+                if t.kind().is_trivia() {
+                    continue;
+                }
+            }
+            return c;
+        }
+    }
+
+    fn record_ignored_comments(&mut self, token: &SyntaxToken) {
+        if token.kind() == SyntaxKind::COMMENT {
+            if let Phase::Second(match_out) = self {
+                if let Some(comment) = ast::Comment::cast(token.clone()) {
+                    match_out.ignored_comments.push(comment);
+                }
+            }
+        }
+    }
+}
+
+fn is_closing_token(kind: SyntaxKind) -> bool {
+    kind == SyntaxKind::R_PAREN || kind == SyntaxKind::R_CURLY || kind == SyntaxKind::R_BRACK
+}
+
+pub(crate) fn record_match_fails_reasons_scope<F, T>(debug_active: bool, f: F) -> T
+where
+    F: Fn() -> T,
+{
+    RECORDING_MATCH_FAIL_REASONS.with(|c| c.set(debug_active));
+    let res = f();
+    RECORDING_MATCH_FAIL_REASONS.with(|c| c.set(false));
+    res
+}
+
+// For performance reasons, we don't want to record the reason why every match fails, only the bit
+// of code that the user indicated they thought would match. We use a thread local to indicate when
+// we are trying to match that bit of code. This saves us having to pass a boolean into all the bits
+// of code that can make the decision to not match.
+thread_local! {
+    pub static RECORDING_MATCH_FAIL_REASONS: Cell<bool> = Cell::new(false);
+}
+
+fn recording_match_fail_reasons() -> bool {
+    RECORDING_MATCH_FAIL_REASONS.with(|c| c.get())
+}
+
+impl PlaceholderMatch {
+    fn new(node: &SyntaxNode, range: FileRange) -> Self {
+        Self { node: Some(node.clone()), range, inner_matches: SsrMatches::default() }
+    }
+
+    fn from_range(range: FileRange) -> Self {
+        Self { node: None, range, inner_matches: SsrMatches::default() }
+    }
+}
+
+impl SsrPattern {
+    pub(crate) fn tree_for_kind(&self, kind: SyntaxKind) -> Result<&SyntaxNode, MatchFailed> {
+        let (tree, kind_name) = if ast::Expr::can_cast(kind) {
+            (&self.expr, "expression")
+        } else if ast::TypeRef::can_cast(kind) {
+            (&self.type_ref, "type reference")
+        } else if ast::ModuleItem::can_cast(kind) {
+            (&self.item, "item")
+        } else if ast::Path::can_cast(kind) {
+            (&self.path, "path")
+        } else if ast::Pat::can_cast(kind) {
+            (&self.pattern, "pattern")
+        } else {
+            fail_match!("Matching nodes of kind {:?} is not supported", kind);
+        };
+        match tree {
+            Some(tree) => Ok(tree),
+            None => fail_match!("Pattern cannot be parsed as a {}", kind_name),
+        }
+    }
+}
+
+impl NodeKind {
+    fn matches(&self, node: &SyntaxNode) -> Result<(), MatchFailed> {
+        let ok = match self {
+            Self::Literal => {
+                mark::hit!(literal_constraint);
+                ast::Literal::can_cast(node.kind())
+            }
+        };
+        if !ok {
+            fail_match!("Code '{}' isn't of kind {:?}", node.text(), self);
+        }
+        Ok(())
+    }
+}
+
+// If `node` contains nothing but an ident then return it, otherwise return None.
+fn only_ident(element: SyntaxElement) -> Option<SyntaxToken> {
+    match element {
+        SyntaxElement::Token(t) => {
+            if t.kind() == SyntaxKind::IDENT {
+                return Some(t);
+            }
+        }
+        SyntaxElement::Node(n) => {
+            let mut children = n.children_with_tokens();
+            if let (Some(only_child), None) = (children.next(), children.next()) {
+                return only_ident(only_child);
+            }
+        }
+    }
+    None
+}
+
+struct PatternIterator {
+    iter: SyntaxElementChildren,
+}
+
+impl Iterator for PatternIterator {
+    type Item = SyntaxElement;
+
+    fn next(&mut self) -> Option<SyntaxElement> {
+        while let Some(element) = self.iter.next() {
+            if !element.kind().is_trivia() {
+                return Some(element);
+            }
+        }
+        None
+    }
+}
+
+impl PatternIterator {
+    fn new(parent: &SyntaxNode) -> Self {
+        Self { iter: parent.children_with_tokens() }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{MatchFinder, SsrRule};
+
+    #[test]
+    fn parse_match_replace() {
+        let rule: SsrRule = "foo($x) ==>> bar($x)".parse().unwrap();
+        let input = "fn foo() {} fn main() { foo(1+2); }";
+
+        use ra_db::fixture::WithFixture;
+        let (db, file_id) = ra_ide_db::RootDatabase::with_single_file(input);
+        let mut match_finder = MatchFinder::new(&db);
+        match_finder.add_rule(rule);
+        let matches = match_finder.find_matches_in_file(file_id);
+        assert_eq!(matches.matches.len(), 1);
+        assert_eq!(matches.matches[0].matched_node.text(), "foo(1+2)");
+        assert_eq!(matches.matches[0].placeholder_values.len(), 1);
+        assert_eq!(
+            matches.matches[0].placeholder_values[&Var("x".to_string())]
+                .node
+                .as_ref()
+                .unwrap()
+                .text(),
+            "1+2"
+        );
+
+        let edit = crate::replacing::matches_to_edit(&matches, input);
+        let mut after = input.to_string();
+        edit.apply(&mut after);
+        assert_eq!(after, "fn foo() {} fn main() { bar(1+2); }");
+    }
+}
diff --git a/crates/ra_ssr/src/parsing.rs b/crates/ra_ssr/src/parsing.rs
new file mode 100644
index 000000000..4aee97bb2
--- /dev/null
+++ b/crates/ra_ssr/src/parsing.rs
@@ -0,0 +1,343 @@
+//! This file contains code for parsing SSR rules, which look something like `foo($a) ==>> bar($b)`.
+//! We first split everything before and after the separator `==>>`. Next, both the search pattern
+//! and the replacement template get tokenized by the Rust tokenizer. Tokens are then searched for
+//! placeholders, which start with `$`. For replacement templates, this is the final form. For
+//! search patterns, we go further and parse the pattern as each kind of thing that we can match.
+//! e.g. expressions, type references etc.
+
+use crate::errors::bail;
+use crate::{SsrError, SsrPattern, SsrRule};
+use ra_syntax::{ast, AstNode, SmolStr, SyntaxKind, T};
+use rustc_hash::{FxHashMap, FxHashSet};
+use std::str::FromStr;
+
+#[derive(Clone, Debug)]
+pub(crate) struct SsrTemplate {
+    pub(crate) tokens: Vec<PatternElement>,
+}
+
+#[derive(Debug)]
+pub(crate) struct RawSearchPattern {
+    tokens: Vec<PatternElement>,
+}
+
+// Part of a search or replace pattern.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum PatternElement {
+    Token(Token),
+    Placeholder(Placeholder),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct Placeholder {
+    /// The name of this placeholder. e.g. for "$a", this would be "a"
+    pub(crate) ident: SmolStr,
+    /// A unique name used in place of this placeholder when we parse the pattern as Rust code.
+    stand_in_name: String,
+    pub(crate) constraints: Vec<Constraint>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum Constraint {
+    Kind(NodeKind),
+    Not(Box<Constraint>),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum NodeKind {
+    Literal,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct Token {
+    kind: SyntaxKind,
+    pub(crate) text: SmolStr,
+}
+
+impl FromStr for SsrRule {
+    type Err = SsrError;
+
+    fn from_str(query: &str) -> Result<SsrRule, SsrError> {
+        let mut it = query.split("==>>");
+        let pattern = it.next().expect("at least empty string").trim();
+        let template = it
+            .next()
+            .ok_or_else(|| SsrError("Cannot find delimiter `==>>`".into()))?
+            .trim()
+            .to_string();
+        if it.next().is_some() {
+            return Err(SsrError("More than one delimiter found".into()));
+        }
+        let rule = SsrRule { pattern: pattern.parse()?, template: template.parse()? };
+        validate_rule(&rule)?;
+        Ok(rule)
+    }
+}
+
+impl FromStr for RawSearchPattern {
+    type Err = SsrError;
+
+    fn from_str(pattern_str: &str) -> Result<RawSearchPattern, SsrError> {
+        Ok(RawSearchPattern { tokens: parse_pattern(pattern_str)? })
+    }
+}
+
+impl RawSearchPattern {
+    /// Returns this search pattern as Rust source code that we can feed to the Rust parser.
+    fn as_rust_code(&self) -> String {
+        let mut res = String::new();
+        for t in &self.tokens {
+            res.push_str(match t {
+                PatternElement::Token(token) => token.text.as_str(),
+                PatternElement::Placeholder(placeholder) => placeholder.stand_in_name.as_str(),
+            });
+        }
+        res
+    }
+
+    fn placeholders_by_stand_in(&self) -> FxHashMap<SmolStr, Placeholder> {
+        let mut res = FxHashMap::default();
+        for t in &self.tokens {
+            if let PatternElement::Placeholder(placeholder) = t {
+                res.insert(SmolStr::new(placeholder.stand_in_name.clone()), placeholder.clone());
+            }
+        }
+        res
+    }
+}
+
+impl FromStr for SsrPattern {
+    type Err = SsrError;
+
+    fn from_str(pattern_str: &str) -> Result<SsrPattern, SsrError> {
+        let raw: RawSearchPattern = pattern_str.parse()?;
+        let raw_str = raw.as_rust_code();
+        let res = SsrPattern {
+            expr: ast::Expr::parse(&raw_str).ok().map(|n| n.syntax().clone()),
+            type_ref: ast::TypeRef::parse(&raw_str).ok().map(|n| n.syntax().clone()),
+            item: ast::ModuleItem::parse(&raw_str).ok().map(|n| n.syntax().clone()),
+            path: ast::Path::parse(&raw_str).ok().map(|n| n.syntax().clone()),
+            pattern: ast::Pat::parse(&raw_str).ok().map(|n| n.syntax().clone()),
+            placeholders_by_stand_in: raw.placeholders_by_stand_in(),
+            raw,
+        };
+        if res.expr.is_none()
+            && res.type_ref.is_none()
+            && res.item.is_none()
+            && res.path.is_none()
+            && res.pattern.is_none()
+        {
+            bail!("Pattern is not a valid Rust expression, type, item, path or pattern");
+        }
+        Ok(res)
+    }
+}
+
+impl FromStr for SsrTemplate {
+    type Err = SsrError;
+
+    fn from_str(pattern_str: &str) -> Result<SsrTemplate, SsrError> {
+        let tokens = parse_pattern(pattern_str)?;
+        // Validate that the template is a valid fragment of Rust code. We reuse the validation
+        // logic for search patterns since the only thing that differs is the error message.
+        if SsrPattern::from_str(pattern_str).is_err() {
+            bail!("Replacement is not a valid Rust expression, type, item, path or pattern");
+        }
+        // Our actual template needs to preserve whitespace, so we can't reuse `tokens`.
+        Ok(SsrTemplate { tokens })
+    }
+}
+
+/// Returns `pattern_str`, parsed as a search or replace pattern. If `remove_whitespace` is true,
+/// then any whitespace tokens will be removed, which we do for the search pattern, but not for the
+/// replace pattern.
+fn parse_pattern(pattern_str: &str) -> Result<Vec<PatternElement>, SsrError> {
+    let mut res = Vec::new();
+    let mut placeholder_names = FxHashSet::default();
+    let mut tokens = tokenize(pattern_str)?.into_iter();
+    while let Some(token) = tokens.next() {
+        if token.kind == T![$] {
+            let placeholder = parse_placeholder(&mut tokens)?;
+            if !placeholder_names.insert(placeholder.ident.clone()) {
+                bail!("Name `{}` repeats more than once", placeholder.ident);
+            }
+            res.push(PatternElement::Placeholder(placeholder));
+        } else {
+            res.push(PatternElement::Token(token));
+        }
+    }
+    Ok(res)
+}
+
+/// Checks for errors in a rule. e.g. the replace pattern referencing placeholders that the search
+/// pattern didn't define.
+fn validate_rule(rule: &SsrRule) -> Result<(), SsrError> {
+    let mut defined_placeholders = FxHashSet::default();
+    for p in &rule.pattern.raw.tokens {
+        if let PatternElement::Placeholder(placeholder) = p {
+            defined_placeholders.insert(&placeholder.ident);
+        }
+    }
+    let mut undefined = Vec::new();
+    for p in &rule.template.tokens {
+        if let PatternElement::Placeholder(placeholder) = p {
+            if !defined_placeholders.contains(&placeholder.ident) {
+                undefined.push(format!("${}", placeholder.ident));
+            }
+            if !placeholder.constraints.is_empty() {
+                bail!("Replacement placeholders cannot have constraints");
+            }
+        }
+    }
+    if !undefined.is_empty() {
+        bail!("Replacement contains undefined placeholders: {}", undefined.join(", "));
+    }
+    Ok(())
+}
+
+fn tokenize(source: &str) -> Result<Vec<Token>, SsrError> {
+    let mut start = 0;
+    let (raw_tokens, errors) = ra_syntax::tokenize(source);
+    if let Some(first_error) = errors.first() {
+        bail!("Failed to parse pattern: {}", first_error);
+    }
+    let mut tokens: Vec<Token> = Vec::new();
+    for raw_token in raw_tokens {
+        let token_len = usize::from(raw_token.len);
+        tokens.push(Token {
+            kind: raw_token.kind,
+            text: SmolStr::new(&source[start..start + token_len]),
+        });
+        start += token_len;
+    }
+    Ok(tokens)
+}
+
+fn parse_placeholder(tokens: &mut std::vec::IntoIter<Token>) -> Result<Placeholder, SsrError> {
+    let mut name = None;
+    let mut constraints = Vec::new();
+    if let Some(token) = tokens.next() {
+        match token.kind {
+            SyntaxKind::IDENT => {
+                name = Some(token.text);
+            }
+            T!['{'] => {
+                let token =
+                    tokens.next().ok_or_else(|| SsrError::new("Unexpected end of placeholder"))?;
+                if token.kind == SyntaxKind::IDENT {
+                    name = Some(token.text);
+                }
+                loop {
+                    let token = tokens
+                        .next()
+                        .ok_or_else(|| SsrError::new("Placeholder is missing closing brace '}'"))?;
+                    match token.kind {
+                        T![:] => {
+                            constraints.push(parse_constraint(tokens)?);
+                        }
+                        T!['}'] => break,
+                        _ => bail!("Unexpected token while parsing placeholder: '{}'", token.text),
+                    }
+                }
+            }
+            _ => {
+                bail!("Placeholders should either be $name or ${{name:constraints}}");
+            }
+        }
+    }
+    let name = name.ok_or_else(|| SsrError::new("Placeholder ($) with no name"))?;
+    Ok(Placeholder::new(name, constraints))
+}
+
+fn parse_constraint(tokens: &mut std::vec::IntoIter<Token>) -> Result<Constraint, SsrError> {
+    let constraint_type = tokens
+        .next()
+        .ok_or_else(|| SsrError::new("Found end of placeholder while looking for a constraint"))?
+        .text
+        .to_string();
+    match constraint_type.as_str() {
+        "kind" => {
+            expect_token(tokens, "(")?;
+            let t = tokens.next().ok_or_else(|| {
+                SsrError::new("Unexpected end of constraint while looking for kind")
+            })?;
+            if t.kind != SyntaxKind::IDENT {
+                bail!("Expected ident, found {:?} while parsing kind constraint", t.kind);
+            }
+            expect_token(tokens, ")")?;
+            Ok(Constraint::Kind(NodeKind::from(&t.text)?))
+        }
+        "not" => {
+            expect_token(tokens, "(")?;
+            let sub = parse_constraint(tokens)?;
+            expect_token(tokens, ")")?;
+            Ok(Constraint::Not(Box::new(sub)))
+        }
+        x => bail!("Unsupported constraint type '{}'", x),
+    }
+}
+
+fn expect_token(tokens: &mut std::vec::IntoIter<Token>, expected: &str) -> Result<(), SsrError> {
+    if let Some(t) = tokens.next() {
+        if t.text == expected {
+            return Ok(());
+        }
+        bail!("Expected {} found {}", expected, t.text);
+    }
+    bail!("Expected {} found end of stream", expected);
+}
+
+impl NodeKind {
+    fn from(name: &SmolStr) -> Result<NodeKind, SsrError> {
+        Ok(match name.as_str() {
+            "literal" => NodeKind::Literal,
+            _ => bail!("Unknown node kind '{}'", name),
+        })
+    }
+}
+
+impl Placeholder {
+    fn new(name: SmolStr, constraints: Vec<Constraint>) -> Self {
+        Self { stand_in_name: format!("__placeholder_{}", name), constraints, ident: name }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parser_happy_case() {
+        fn token(kind: SyntaxKind, text: &str) -> PatternElement {
+            PatternElement::Token(Token { kind, text: SmolStr::new(text) })
+        }
+        fn placeholder(name: &str) -> PatternElement {
+            PatternElement::Placeholder(Placeholder::new(SmolStr::new(name), Vec::new()))
+        }
+        let result: SsrRule = "foo($a, $b) ==>> bar($b, $a)".parse().unwrap();
+        assert_eq!(
+            result.pattern.raw.tokens,
+            vec![
+                token(SyntaxKind::IDENT, "foo"),
+                token(T!['('], "("),
+                placeholder("a"),
+                token(T![,], ","),
+                token(SyntaxKind::WHITESPACE, " "),
+                placeholder("b"),
+                token(T![')'], ")"),
+            ]
+        );
+        assert_eq!(
+            result.template.tokens,
+            vec![
+                token(SyntaxKind::IDENT, "bar"),
+                token(T!['('], "("),
+                placeholder("b"),
+                token(T![,], ","),
+                token(SyntaxKind::WHITESPACE, " "),
+                placeholder("a"),
+                token(T![')'], ")"),
+            ]
+        );
+    }
+}
diff --git a/crates/ra_ssr/src/replacing.rs b/crates/ra_ssr/src/replacing.rs
new file mode 100644
index 000000000..e43cc5167
--- /dev/null
+++ b/crates/ra_ssr/src/replacing.rs
@@ -0,0 +1,66 @@
+//! Code for applying replacement templates for matches that have previously been found.
+
+use crate::matching::Var;
+use crate::parsing::PatternElement;
+use crate::{Match, SsrMatches};
+use ra_syntax::ast::AstToken;
+use ra_syntax::TextSize;
+use ra_text_edit::TextEdit;
+
+/// Returns a text edit that will replace each match in `matches` with its corresponding replacement
+/// template. Placeholders in the template will have been substituted with whatever they matched to
+/// in the original code.
+pub(crate) fn matches_to_edit(matches: &SsrMatches, file_src: &str) -> TextEdit {
+    matches_to_edit_at_offset(matches, file_src, 0.into())
+}
+
+fn matches_to_edit_at_offset(
+    matches: &SsrMatches,
+    file_src: &str,
+    relative_start: TextSize,
+) -> TextEdit {
+    let mut edit_builder = ra_text_edit::TextEditBuilder::default();
+    for m in &matches.matches {
+        edit_builder.replace(
+            m.range.range.checked_sub(relative_start).unwrap(),
+            render_replace(m, file_src),
+        );
+    }
+    edit_builder.finish()
+}
+
+fn render_replace(match_info: &Match, file_src: &str) -> String {
+    let mut out = String::new();
+    for r in &match_info.template.tokens {
+        match r {
+            PatternElement::Token(t) => out.push_str(t.text.as_str()),
+            PatternElement::Placeholder(p) => {
+                if let Some(placeholder_value) =
+                    match_info.placeholder_values.get(&Var(p.ident.to_string()))
+                {
+                    let range = &placeholder_value.range.range;
+                    let mut matched_text =
+                        file_src[usize::from(range.start())..usize::from(range.end())].to_owned();
+                    let edit = matches_to_edit_at_offset(
+                        &placeholder_value.inner_matches,
+                        file_src,
+                        range.start(),
+                    );
+                    edit.apply(&mut matched_text);
+                    out.push_str(&matched_text);
+                } else {
+                    // We validated that all placeholder references were valid before we
+                    // started, so this shouldn't happen.
+                    panic!(
+                        "Internal error: replacement referenced unknown placeholder {}",
+                        p.ident
+                    );
+                }
+            }
+        }
+    }
+    for comment in &match_info.ignored_comments {
+        out.push_str(&comment.syntax().to_string());
+    }
+    out
+}
diff --git a/crates/ra_ssr/src/tests.rs b/crates/ra_ssr/src/tests.rs
new file mode 100644
index 000000000..f20ae2cdf
--- /dev/null
+++ b/crates/ra_ssr/src/tests.rs
@@ -0,0 +1,582 @@
+use crate::{MatchFinder, SsrRule};
+use ra_db::{FileId, SourceDatabaseExt};
+use test_utils::mark;
+
+fn parse_error_text(query: &str) -> String {
+    format!("{}", query.parse::<SsrRule>().unwrap_err())
+}
+
+#[test]
+fn parser_empty_query() {
+    assert_eq!(parse_error_text(""), "Parse error: Cannot find delimiter `==>>`");
+}
+
+#[test]
+fn parser_no_delimiter() {
+    assert_eq!(parse_error_text("foo()"), "Parse error: Cannot find delimiter `==>>`");
+}
+
+#[test]
+fn parser_two_delimiters() {
+    assert_eq!(
+        parse_error_text("foo() ==>> a ==>> b "),
+        "Parse error: More than one delimiter found"
+    );
+}
+
+#[test]
+fn parser_repeated_name() {
+    assert_eq!(
+        parse_error_text("foo($a, $a) ==>>"),
+        "Parse error: Name `a` repeats more than once"
+    );
+}
+
+#[test]
+fn parser_invalid_pattern() {
+    assert_eq!(
+        parse_error_text(" ==>> ()"),
+        "Parse error: Pattern is not a valid Rust expression, type, item, path or pattern"
+    );
+}
+
+#[test]
+fn parser_invalid_template() {
+    assert_eq!(
+        parse_error_text("() ==>> )"),
+        "Parse error: Replacement is not a valid Rust expression, type, item, path or pattern"
+    );
+}
+
+#[test]
+fn parser_undefined_placeholder_in_replacement() {
+    assert_eq!(
+        parse_error_text("42 ==>> $a"),
+        "Parse error: Replacement contains undefined placeholders: $a"
+    );
+}
+
+fn single_file(code: &str) -> (ra_ide_db::RootDatabase, FileId) {
+    use ra_db::fixture::WithFixture;
+    ra_ide_db::RootDatabase::with_single_file(code)
+}
+
+fn assert_ssr_transform(rule: &str, input: &str, result: &str) {
+    assert_ssr_transforms(&[rule], input, result);
+}
+
+fn normalize_code(code: &str) -> String {
+    let (db, file_id) = single_file(code);
+    db.file_text(file_id).to_string()
+}
+
+fn assert_ssr_transforms(rules: &[&str], input: &str, result: &str) {
+    let (db, file_id) = single_file(input);
+    let mut match_finder = MatchFinder::new(&db);
+    for rule in rules {
+        let rule: SsrRule = rule.parse().unwrap();
+        match_finder.add_rule(rule);
+    }
+    if let Some(edits) = match_finder.edits_for_file(file_id) {
+        // Note, db.file_text is not necessarily the same as `input`, since fixture parsing alters
+        // stuff.
+        let mut after = db.file_text(file_id).to_string();
+        edits.apply(&mut after);
+        // Likewise, we need to make sure that whatever transformations fixture parsing applies,
+        // also get applied to our expected result.
+        let result = normalize_code(result);
+        assert_eq!(after, result);
+    } else {
+        panic!("No edits were made");
+    }
+}
+
+fn print_match_debug_info(match_finder: &MatchFinder, file_id: FileId, snippet: &str) {
+    let debug_info = match_finder.debug_where_text_equal(file_id, snippet);
+    println!(
+        "Match debug info: {} nodes had text exactly equal to '{}'",
+        debug_info.len(),
+        snippet
+    );
+    for (index, d) in debug_info.iter().enumerate() {
+        println!("Node #{}\n{:#?}\n", index, d);
+    }
+}
+
+fn assert_matches(pattern: &str, code: &str, expected: &[&str]) {
+    let (db, file_id) = single_file(code);
+    let mut match_finder = MatchFinder::new(&db);
+    match_finder.add_search_pattern(pattern.parse().unwrap());
+    let matched_strings: Vec<String> = match_finder
+        .find_matches_in_file(file_id)
+        .flattened()
+        .matches
+        .iter()
+        .map(|m| m.matched_text())
+        .collect();
+    if matched_strings != expected && !expected.is_empty() {
+        print_match_debug_info(&match_finder, file_id, &expected[0]);
+    }
+    assert_eq!(matched_strings, expected);
+}
+
+fn assert_no_match(pattern: &str, code: &str) {
+    let (db, file_id) = single_file(code);
+    let mut match_finder = MatchFinder::new(&db);
+    match_finder.add_search_pattern(pattern.parse().unwrap());
+    let matches = match_finder.find_matches_in_file(file_id).flattened().matches;
+    if !matches.is_empty() {
+        print_match_debug_info(&match_finder, file_id, &matches[0].matched_text());
+        panic!("Got {} matches when we expected none: {:#?}", matches.len(), matches);
+    }
+}
+
+fn assert_match_failure_reason(pattern: &str, code: &str, snippet: &str, expected_reason: &str) {
+    let (db, file_id) = single_file(code);
+    let mut match_finder = MatchFinder::new(&db);
+    match_finder.add_search_pattern(pattern.parse().unwrap());
+    let mut reasons = Vec::new();
+    for d in match_finder.debug_where_text_equal(file_id, snippet) {
+        if let Some(reason) = d.match_failure_reason() {
+            reasons.push(reason.to_owned());
+        }
+    }
+    assert_eq!(reasons, vec![expected_reason]);
+}
+
+#[test]
+fn ssr_function_to_method() {
+    assert_ssr_transform(
+        "my_function($a, $b) ==>> ($a).my_method($b)",
+        "fn my_function() {} fn main() { loop { my_function( other_func(x, y), z + w) } }",
+        "fn my_function() {} fn main() { loop { (other_func(x, y)).my_method(z + w) } }",
+    )
+}
+
+#[test]
+fn ssr_nested_function() {
+    assert_ssr_transform(
+        "foo($a, $b, $c) ==>> bar($c, baz($a, $b))",
+        "fn foo() {} fn main { foo  (x + value.method(b), x+y-z, true && false) }",
+        "fn foo() {} fn main { bar(true && false, baz(x + value.method(b), x+y-z)) }",
+    )
+}
+
+#[test]
+fn ssr_expected_spacing() {
+    assert_ssr_transform(
+        "foo($x) + bar() ==>> bar($x)",
+        "fn foo() {} fn bar() {} fn main() { foo(5) + bar() }",
+        "fn foo() {} fn bar() {} fn main() { bar(5) }",
+    );
+}
+
+#[test]
+fn ssr_with_extra_space() {
+    assert_ssr_transform(
+        "foo($x  ) +    bar() ==>> bar($x)",
+        "fn foo() {} fn bar() {} fn main() { foo(  5 )  +bar(   ) }",
+        "fn foo() {} fn bar() {} fn main() { bar(5) }",
+    );
+}
+
+#[test]
+fn ssr_keeps_nested_comment() {
+    assert_ssr_transform(
+        "foo($x) ==>> bar($x)",
+        "fn foo() {} fn main() { foo(other(5 /* using 5 */)) }",
+        "fn foo() {} fn main() { bar(other(5 /* using 5 */)) }",
+    )
+}
+
+#[test]
+fn ssr_keeps_comment() {
+    assert_ssr_transform(
+        "foo($x) ==>> bar($x)",
+        "fn foo() {} fn main() { foo(5 /* using 5 */) }",
+        "fn foo() {} fn main() { bar(5)/* using 5 */ }",
+    )
+}
+
+#[test]
+fn ssr_struct_lit() {
+    assert_ssr_transform(
+        "foo{a: $a, b: $b} ==>> foo::new($a, $b)",
+        "fn foo() {} fn main() { foo{b:2, a:1} }",
+        "fn foo() {} fn main() { foo::new(1, 2) }",
+    )
+}
+
+#[test]
+fn ignores_whitespace() {
+    assert_matches("1+2", "fn f() -> i32 {1  +  2}", &["1  +  2"]);
+    assert_matches("1 + 2", "fn f() -> i32 {1+2}", &["1+2"]);
+}
+
+#[test]
+fn no_match() {
+    assert_no_match("1 + 3", "fn f() -> i32 {1  +  2}");
+}
+
+#[test]
+fn match_fn_definition() {
+    assert_matches("fn $a($b: $t) {$c}", "fn f(a: i32) {bar()}", &["fn f(a: i32) {bar()}"]);
+}
+
+#[test]
+fn match_struct_definition() {
+    let code = r#"
+        struct Option<T> {}
+        struct Bar {}
+        struct Foo {name: Option<String>}"#;
+    assert_matches("struct $n {$f: Option<String>}", code, &["struct Foo {name: Option<String>}"]);
+}
+
+#[test]
+fn match_expr() {
+    let code = r#"
+        fn foo() {}
+        fn f() -> i32 {foo(40 + 2, 42)}"#;
+    assert_matches("foo($a, $b)", code, &["foo(40 + 2, 42)"]);
+    assert_no_match("foo($a, $b, $c)", code);
+    assert_no_match("foo($a)", code);
+}
+
+#[test]
+fn match_nested_method_calls() {
+    assert_matches(
+        "$a.z().z().z()",
+        "fn f() {h().i().j().z().z().z().d().e()}",
+        &["h().i().j().z().z().z()"],
+    );
+}
+
+// Make sure that our node matching semantics don't differ within macro calls.
+#[test]
+fn match_nested_method_calls_with_macro_call() {
+    assert_matches(
+        "$a.z().z().z()",
+        r#"
+            macro_rules! m1 { ($a:expr) => {$a}; }
+            fn f() {m1!(h().i().j().z().z().z().d().e())}"#,
+        &["h().i().j().z().z().z()"],
+    );
+}
+
+#[test]
+fn match_complex_expr() {
+    let code = r#"
+        fn foo() {} fn bar() {}
+        fn f() -> i32 {foo(bar(40, 2), 42)}"#;
+    assert_matches("foo($a, $b)", code, &["foo(bar(40, 2), 42)"]);
+    assert_no_match("foo($a, $b, $c)", code);
+    assert_no_match("foo($a)", code);
+    assert_matches("bar($a, $b)", code, &["bar(40, 2)"]);
+}
+
+// Trailing commas in the code should be ignored.
+#[test]
+fn match_with_trailing_commas() {
+    // Code has comma, pattern doesn't.
+    assert_matches("foo($a, $b)", "fn foo() {} fn f() {foo(1, 2,);}", &["foo(1, 2,)"]);
+    assert_matches("Foo{$a, $b}", "struct Foo {} fn f() {Foo{1, 2,};}", &["Foo{1, 2,}"]);
+
+    // Pattern has comma, code doesn't.
+    assert_matches("foo($a, $b,)", "fn foo() {} fn f() {foo(1, 2);}", &["foo(1, 2)"]);
+    assert_matches("Foo{$a, $b,}", "struct Foo {} fn f() {Foo{1, 2};}", &["Foo{1, 2}"]);
+}
+
+#[test]
+fn match_type() {
+    assert_matches("i32", "fn f() -> i32 {1  +  2}", &["i32"]);
+    assert_matches(
+        "Option<$a>",
+        "struct Option<T> {} fn f() -> Option<i32> {42}",
+        &["Option<i32>"],
+    );
+    assert_no_match(
+        "Option<$a>",
+        "struct Option<T> {} struct Result<T, E> {} fn f() -> Result<i32, ()> {42}",
+    );
+}
+
+#[test]
+fn match_struct_instantiation() {
+    let code = r#"
+        struct Foo {bar: i32, baz: i32}
+        fn f() {Foo {bar: 1, baz: 2}}"#;
+    assert_matches("Foo {bar: 1, baz: 2}", code, &["Foo {bar: 1, baz: 2}"]);
+    // Now with placeholders for all parts of the struct.
+    assert_matches("Foo {$a: $b, $c: $d}", code, &["Foo {bar: 1, baz: 2}"]);
+    assert_matches("Foo {}", "struct Foo {} fn f() {Foo {}}", &["Foo {}"]);
+}
+
+#[test]
+fn match_path() {
+    let code = r#"
+        mod foo {
+            fn bar() {}
+        }
+        fn f() {foo::bar(42)}"#;
+    assert_matches("foo::bar", code, &["foo::bar"]);
+    assert_matches("$a::bar", code, &["foo::bar"]);
+    assert_matches("foo::$b", code, &["foo::bar"]);
+}
+
+#[test]
+fn match_pattern() {
+    assert_matches("Some($a)", "struct Some(); fn f() {if let Some(x) = foo() {}}", &["Some(x)"]);
+}
+
+#[test]
+fn literal_constraint() {
+    mark::check!(literal_constraint);
+    let code = r#"
+        enum Option<T> { Some(T), None }
+        use Option::Some;
+        fn f1() {
+            let x1 = Some(42);
+            let x2 = Some("foo");
+            let x3 = Some(x1);
+            let x4 = Some(40 + 2);
+            let x5 = Some(true);
+        }
+        "#;
+    assert_matches("Some(${a:kind(literal)})", code, &["Some(42)", "Some(\"foo\")", "Some(true)"]);
+    assert_matches("Some(${a:not(kind(literal))})", code, &["Some(x1)", "Some(40 + 2)"]);
+}
+
+#[test]
+fn match_reordered_struct_instantiation() {
+    assert_matches(
+        "Foo {aa: 1, b: 2, ccc: 3}",
+        "struct Foo {} fn f() {Foo {b: 2, ccc: 3, aa: 1}}",
+        &["Foo {b: 2, ccc: 3, aa: 1}"],
+    );
+    assert_no_match("Foo {a: 1}", "struct Foo {} fn f() {Foo {b: 1}}");
+    assert_no_match("Foo {a: 1}", "struct Foo {} fn f() {Foo {a: 2}}");
+    assert_no_match("Foo {a: 1, b: 2}", "struct Foo {} fn f() {Foo {a: 1}}");
+    assert_no_match("Foo {a: 1, b: 2}", "struct Foo {} fn f() {Foo {b: 2}}");
+    assert_no_match("Foo {a: 1, }", "struct Foo {} fn f() {Foo {a: 1, b: 2}}");
+    assert_no_match("Foo {a: 1, z: 9}", "struct Foo {} fn f() {Foo {a: 1}}");
+}
+
+#[test]
+fn match_macro_invocation() {
+    assert_matches(
+        "foo!($a)",
+        "macro_rules! foo {() => {}} fn() {foo(foo!(foo()))}",
+        &["foo!(foo())"],
+    );
+    assert_matches(
+        "foo!(41, $a, 43)",
+        "macro_rules! foo {() => {}} fn() {foo!(41, 42, 43)}",
+        &["foo!(41, 42, 43)"],
+    );
+    assert_no_match("foo!(50, $a, 43)", "macro_rules! foo {() => {}} fn() {foo!(41, 42, 43}");
+    assert_no_match("foo!(41, $a, 50)", "macro_rules! foo {() => {}} fn() {foo!(41, 42, 43}");
+    assert_matches(
+        "foo!($a())",
+        "macro_rules! foo {() => {}} fn() {foo!(bar())}",
+        &["foo!(bar())"],
+    );
+}
+
+// When matching within a macro expansion, we only allow matches of nodes that originated from
+// the macro call, not from the macro definition.
+#[test]
+fn no_match_expression_from_macro() {
+    assert_no_match(
+        "$a.clone()",
+        r#"
+            macro_rules! m1 {
+                () => {42.clone()}
+            }
+            fn f1() {m1!()}
+            "#,
+    );
+}
+
+// We definitely don't want to allow matching of an expression that part originates from the
+// macro call `42` and part from the macro definition `.clone()`.
+#[test]
+fn no_match_split_expression() {
+    assert_no_match(
+        "$a.clone()",
+        r#"
+            macro_rules! m1 {
+                ($x:expr) => {$x.clone()}
+            }
+            fn f1() {m1!(42)}
+            "#,
+    );
+}
+
+#[test]
+fn replace_function_call() {
+    assert_ssr_transform(
+        "foo() ==>> bar()",
+        "fn foo() {} fn f1() {foo(); foo();}",
+        "fn foo() {} fn f1() {bar(); bar();}",
+    );
+}
+
+#[test]
+fn replace_function_call_with_placeholders() {
+    assert_ssr_transform(
+        "foo($a, $b) ==>> bar($b, $a)",
+        "fn foo() {} fn f1() {foo(5, 42)}",
+        "fn foo() {} fn f1() {bar(42, 5)}",
+    );
+}
+
+#[test]
+fn replace_nested_function_calls() {
+    assert_ssr_transform(
+        "foo($a) ==>> bar($a)",
+        "fn foo() {} fn f1() {foo(foo(42))}",
+        "fn foo() {} fn f1() {bar(bar(42))}",
+    );
+}
+
+#[test]
+fn replace_type() {
+    assert_ssr_transform(
+        "Result<(), $a> ==>> Option<$a>",
+        "struct Result<T, E> {} fn f1() -> Result<(), Vec<Error>> {foo()}",
+        "struct Result<T, E> {} fn f1() -> Option<Vec<Error>> {foo()}",
+    );
+}
+
+#[test]
+fn replace_struct_init() {
+    assert_ssr_transform(
+        "Foo {a: $a, b: $b} ==>> Foo::new($a, $b)",
+        "struct Foo {} fn f1() {Foo{b: 1, a: 2}}",
+        "struct Foo {} fn f1() {Foo::new(2, 1)}",
+    );
+}
+
+#[test]
+fn replace_macro_invocations() {
+    assert_ssr_transform(
+        "try!($a) ==>> $a?",
+        "macro_rules! try {() => {}} fn f1() -> Result<(), E> {bar(try!(foo()));}",
+        "macro_rules! try {() => {}} fn f1() -> Result<(), E> {bar(foo()?);}",
+    );
+    assert_ssr_transform(
+        "foo!($a($b)) ==>> foo($b, $a)",
+        "macro_rules! foo {() => {}} fn f1() {foo!(abc(def() + 2));}",
+        "macro_rules! foo {() => {}} fn f1() {foo(def() + 2, abc);}",
+    );
+}
+
+#[test]
+fn replace_binary_op() {
+    assert_ssr_transform(
+        "$a + $b ==>> $b + $a",
+        "fn f() {2 * 3 + 4 * 5}",
+        "fn f() {4 * 5 + 2 * 3}",
+    );
+    assert_ssr_transform(
+        "$a + $b ==>> $b + $a",
+        "fn f() {1 + 2 + 3 + 4}",
+        "fn f() {4 + 3 + 2 + 1}",
+    );
+}
+
+#[test]
+fn match_binary_op() {
+    assert_matches("$a + $b", "fn f() {1 + 2 + 3 + 4}", &["1 + 2", "1 + 2 + 3", "1 + 2 + 3 + 4"]);
+}
+
+#[test]
+fn multiple_rules() {
+    assert_ssr_transforms(
+        &["$a + 1 ==>> add_one($a)", "$a + $b ==>> add($a, $b)"],
+        "fn f() -> i32 {3 + 2 + 1}",
+        "fn f() -> i32 {add_one(add(3, 2))}",
+    )
+}
+
+#[test]
+fn match_within_macro_invocation() {
+    let code = r#"
+            macro_rules! foo {
+                ($a:stmt; $b:expr) => {
+                    $b
+                };
+            }
+            struct A {}
+            impl A {
+                fn bar() {}
+            }
+            fn f1() {
+                let aaa = A {};
+                foo!(macro_ignores_this(); aaa.bar());
+            }
+        "#;
+    assert_matches("$a.bar()", code, &["aaa.bar()"]);
+}
+
+#[test]
+fn replace_within_macro_expansion() {
+    assert_ssr_transform(
+        "$a.foo() ==>> bar($a)",
+        r#"
+            macro_rules! macro1 {
+                ($a:expr) => {$a}
+            }
+            fn f() {macro1!(5.x().foo().o2())}"#,
+        r#"
+            macro_rules! macro1 {
+                ($a:expr) => {$a}
+            }
+            fn f() {macro1!(bar(5.x()).o2())}"#,
+    )
+}
+
+#[test]
+fn preserves_whitespace_within_macro_expansion() {
+    assert_ssr_transform(
+        "$a + $b ==>> $b - $a",
+        r#"
+            macro_rules! macro1 {
+                ($a:expr) => {$a}
+            }
+            fn f() {macro1!(1   *   2 + 3 + 4}"#,
+        r#"
+            macro_rules! macro1 {
+                ($a:expr) => {$a}
+            }
+            fn f() {macro1!(4 - 3 - 1   *   2}"#,
+    )
+}
+
+#[test]
+fn match_failure_reasons() {
+    let code = r#"
+        fn bar() {}
+        macro_rules! foo {
+            ($a:expr) => {
+                1 + $a + 2
+            };
+        }
+        fn f1() {
+            bar(1, 2);
+            foo!(5 + 43.to_string() + 5);
+        }
+        "#;
+    assert_match_failure_reason(
+        "bar($a, 3)",
+        code,
+        "bar(1, 2)",
+        r#"Pattern wanted token '3' (INT_NUMBER), but code had token '2' (INT_NUMBER)"#,
+    );
+    assert_match_failure_reason(
+        "42.to_string()",
+        code,
+        "43.to_string()",
+        r#"Pattern wanted token '42' (INT_NUMBER), but code had token '43' (INT_NUMBER)"#,
+    );
+}
diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index a8ff2e74f..57cc09854 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 [dependencies]
 itertools = "0.9.0"
 rowan = "0.10.0"
-rustc_lexer = { version = "661.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "666.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 arrayvec = "0.5.1"
 once_cell = "1.3.1"
@@ -31,4 +31,6 @@ serde = { version = "1.0.106", features = ["derive"] }
 
 [dev-dependencies]
 test_utils = { path = "../test_utils" }
+expect = { path = "../expect" }
 walkdir = "2.3.1"
+rayon = "1"
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 664894d1f..26b3c813a 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -41,6 +41,10 @@ pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextSize) ->
     ancestors_at_offset(syntax, offset).find_map(N::cast)
 }
 
+pub fn find_node_at_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
+    find_covering_element(syntax, range).ancestors().find_map(N::cast)
+}
+
 /// Skip to next non `trivia` token
 pub fn skip_trivia_token(mut token: SyntaxToken, direction: Direction) -> Option<SyntaxToken> {
     while token.kind().is_trivia() {
@@ -290,6 +294,11 @@ impl<'a> SyntaxRewriter<'a> {
         N::cast(self.rewrite(node.syntax())).unwrap()
     }
 
+    /// Returns a node that encompasses all replacements to be done by this rewriter.
+    ///
+    /// Passing the returned node to `rewrite` will apply all replacements queued up in `self`.
+    ///
+    /// Returns `None` when there are no replacements.
     pub fn rewrite_root(&self) -> Option<SyntaxNode> {
         assert!(self.f.is_none());
         self.replacements
@@ -298,6 +307,9 @@ impl<'a> SyntaxRewriter<'a> {
                 SyntaxElement::Node(it) => it.clone(),
                 SyntaxElement::Token(it) => it.parent(),
             })
+            // If we only have one replacement, we must return its parent node, since `rewrite` does
+            // not replace the node passed to it.
+            .map(|it| it.parent().unwrap_or(it))
             .fold1(|a, b| least_common_ancestor(&a, &b).unwrap())
     }
 
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 1876afe95..9d02aeef3 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -75,7 +75,7 @@ impl<N> AstChildren<N> {
 impl<N: AstNode> Iterator for AstChildren<N> {
     type Item = N;
     fn next(&mut self) -> Option<N> {
-        self.inner.by_ref().find_map(N::cast)
+        self.inner.find_map(N::cast)
     }
 }
 
@@ -285,6 +285,8 @@ where
     let pred = predicates.next().unwrap();
     let mut bounds = pred.type_bound_list().unwrap().bounds();
 
+    assert!(pred.for_token().is_none());
+    assert!(pred.type_param_list().is_none());
     assert_eq!("T", pred.type_ref().unwrap().syntax().text().to_string());
     assert_bound("Clone", bounds.next());
     assert_bound("Copy", bounds.next());
@@ -322,6 +324,8 @@ where
     let pred = predicates.next().unwrap();
     let mut bounds = pred.type_bound_list().unwrap().bounds();
 
-    assert_eq!("for<'a> F", pred.type_ref().unwrap().syntax().text().to_string());
+    assert!(pred.for_token().is_some());
+    assert_eq!("<'a>", pred.type_param_list().unwrap().syntax().text().to_string());
+    assert_eq!("F", pred.type_ref().unwrap().syntax().text().to_string());
     assert_bound("Fn(&'a str)", bounds.next());
 }
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 29eb3fcb9..abc7a646c 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -189,6 +189,21 @@ impl ast::RecordFieldList {
     }
 }
 
+impl ast::TypeAliasDef {
+    #[must_use]
+    pub fn remove_bounds(&self) -> ast::TypeAliasDef {
+        let colon = match self.colon_token() {
+            Some(it) => it,
+            None => return self.clone(),
+        };
+        let end = match self.type_bound_list() {
+            Some(it) => it.syntax().clone().into(),
+            None => colon.clone().into(),
+        };
+        self.replace_children(colon.into()..=end, iter::empty())
+    }
+}
+
 impl ast::TypeParam {
     #[must_use]
     pub fn remove_bounds(&self) -> ast::TypeParam {
@@ -299,12 +314,8 @@ impl ast::UseTree {
             Some(it) => it,
             None => return self.clone(),
         };
-        let use_tree = make::use_tree(
-            suffix.clone(),
-            self.use_tree_list(),
-            self.alias(),
-            self.star_token().is_some(),
-        );
+        let use_tree =
+            make::use_tree(suffix, self.use_tree_list(), self.alias(), self.star_token().is_some());
         let nested = make::use_tree_list(iter::once(use_tree));
         return make::use_tree(prefix.clone(), Some(nested), None, false);
 
@@ -579,12 +590,17 @@ pub trait AstNodeEdit: AstNode + Clone + Sized {
         rewriter.rewrite_ast(self)
     }
     #[must_use]
-    fn indent(&self, indent: IndentLevel) -> Self {
-        Self::cast(indent.increase_indent(self.syntax().clone())).unwrap()
+    fn indent(&self, level: IndentLevel) -> Self {
+        Self::cast(level.increase_indent(self.syntax().clone())).unwrap()
+    }
+    #[must_use]
+    fn dedent(&self, level: IndentLevel) -> Self {
+        Self::cast(level.decrease_indent(self.syntax().clone())).unwrap()
     }
     #[must_use]
-    fn dedent(&self, indent: IndentLevel) -> Self {
-        Self::cast(indent.decrease_indent(self.syntax().clone())).unwrap()
+    fn reset_indent(&self) -> Self {
+        let level = IndentLevel::from_node(self.syntax());
+        self.dedent(level)
     }
 }
 
diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
index 7771d6759..db5438d68 100644
--- a/crates/ra_syntax/src/ast/expr_extensions.rs
+++ b/crates/ra_syntax/src/ast/expr_extensions.rs
@@ -399,10 +399,7 @@ impl ast::BlockExpr {
             Some(it) => it,
             None => return true,
         };
-        match parent.kind() {
-            FN_DEF | IF_EXPR | WHILE_EXPR | LOOP_EXPR | EFFECT_EXPR => false,
-            _ => true,
-        }
+        !matches!(parent.kind(), FN_DEF | IF_EXPR | WHILE_EXPR | LOOP_EXPR | EFFECT_EXPR)
     }
 }
 
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index 98c38d009..662c6f73e 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -459,16 +459,16 @@ impl ast::RangePat {
 
 impl ast::TokenTree {
     pub fn left_delimiter_token(&self) -> Option<SyntaxToken> {
-        self.syntax().first_child_or_token()?.into_token().filter(|it| match it.kind() {
-            T!['{'] | T!['('] | T!['['] => true,
-            _ => false,
-        })
+        self.syntax()
+            .first_child_or_token()?
+            .into_token()
+            .filter(|it| matches!(it.kind(), T!['{'] | T!['('] | T!['[']))
     }
 
     pub fn right_delimiter_token(&self) -> Option<SyntaxToken> {
-        self.syntax().last_child_or_token()?.into_token().filter(|it| match it.kind() {
-            T!['}'] | T![')'] | T![']'] => true,
-            _ => false,
-        })
+        self.syntax()
+            .last_child_or_token()?
+            .into_token()
+            .filter(|it| matches!(it.kind(), T!['}'] | T![')'] | T![']']))
     }
 }
diff --git a/crates/ra_syntax/src/ast/generated/nodes.rs b/crates/ra_syntax/src/ast/generated/nodes.rs
index cb430ca01..58141da11 100644
--- a/crates/ra_syntax/src/ast/generated/nodes.rs
+++ b/crates/ra_syntax/src/ast/generated/nodes.rs
@@ -2052,6 +2052,8 @@ pub struct WherePred {
 }
 impl ast::TypeBoundsOwner for WherePred {}
 impl WherePred {
+    pub fn for_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![for]) }
+    pub fn type_param_list(&self) -> Option<TypeParamList> { support::child(&self.syntax) }
     pub fn lifetime_token(&self) -> Option<SyntaxToken> {
         support::token(&self.syntax, T![lifetime])
     }
@@ -4849,687 +4851,687 @@ impl AstNode for FieldDefList {
     }
 }
 impl std::fmt::Display for NominalDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for GenericParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for GenericArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeRef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ModuleItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AssocItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Expr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Pat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordInnerPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AttrInput {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Stmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SourceFile {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FnDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RetType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for StructDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UnionDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleFieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleFieldDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumVariantList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumVariant {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TraitDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Module {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ItemList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for StaticDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeAliasDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ImplDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for NeverType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PointerType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArrayType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SliceType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ReferenceType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PlaceholderType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FnPointerType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ForType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ImplTraitType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for DynTraitType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArrayExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LambdaExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for IfExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LoopExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EffectExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ForExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WhileExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ContinueExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BreakExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Label {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BlockExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ReturnExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for CallExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MethodCallExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for IndexExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FieldExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AwaitExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TryExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for CastExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RefExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PrefixExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BoxExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RangeExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BinExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Literal {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchArmList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchArm {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchGuard {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordLit {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordField {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for OrPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RefPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BoxPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BindPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PlaceholderPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for DotDotPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SlicePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RangePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LiteralPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldPatList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleStructPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TuplePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Visibility {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Name {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for NameRef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroCall {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Attr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TokenTree {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeParamList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LifetimeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeBound {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeBoundList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WherePred {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WhereClause {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Abi {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExprStmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LetStmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Condition {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParamList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SelfParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Param {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseTree {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Alias {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseTreeList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternCrateItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArgList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Path {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathSegment {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeArgList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AssocTypeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LifetimeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroItems {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroStmts {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternItemList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternBlock {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MetaItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
diff --git a/crates/ra_syntax/src/ast/generated/tokens.rs b/crates/ra_syntax/src/ast/generated/tokens.rs
index f91befaac..abadd0b61 100644
--- a/crates/ra_syntax/src/ast/generated/tokens.rs
+++ b/crates/ra_syntax/src/ast/generated/tokens.rs
@@ -11,7 +11,7 @@ pub struct Whitespace {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for Whitespace {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -32,7 +32,7 @@ pub struct Comment {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for Comment {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -53,7 +53,7 @@ pub struct String {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for String {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -74,7 +74,7 @@ pub struct RawString {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for RawString {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index da0eb0926..192c610f1 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -75,6 +75,10 @@ pub fn record_field(name: ast::NameRef, expr: Option<ast::Expr>) -> ast::RecordF
     }
 }
 
+pub fn record_field_def(name: ast::NameRef, ty: ast::TypeRef) -> ast::RecordFieldDef {
+    ast_from_text(&format!("struct S {{ {}: {}, }}", name, ty))
+}
+
 pub fn block_expr(
     stmts: impl IntoIterator<Item = ast::Stmt>,
     tail_expr: Option<ast::Expr>,
diff --git a/crates/ra_syntax/src/ast/tokens.rs b/crates/ra_syntax/src/ast/tokens.rs
index 3cd6d99c3..045f69133 100644
--- a/crates/ra_syntax/src/ast/tokens.rs
+++ b/crates/ra_syntax/src/ast/tokens.rs
@@ -1,6 +1,9 @@
 //! There are many AstNodes, but only a few tokens, so we hand-write them here.
 
-use std::convert::{TryFrom, TryInto};
+use std::{
+    borrow::Cow,
+    convert::{TryFrom, TryInto},
+};
 
 use crate::{
     ast::{AstToken, Comment, RawString, String, Whitespace},
@@ -84,7 +87,7 @@ impl Whitespace {
 }
 
 pub struct QuoteOffsets {
-    pub quotes: [TextRange; 2],
+    pub quotes: (TextRange, TextRange),
     pub contents: TextRange,
 }
 
@@ -103,7 +106,7 @@ impl QuoteOffsets {
         let end = TextSize::of(literal);
 
         let res = QuoteOffsets {
-            quotes: [TextRange::new(start, left_quote), TextRange::new(right_quote, end)],
+            quotes: (TextRange::new(start, left_quote), TextRange::new(right_quote, end)),
             contents: TextRange::new(left_quote, right_quote),
         };
         Some(res)
@@ -116,17 +119,17 @@ pub trait HasQuotes: AstToken {
         let offsets = QuoteOffsets::new(text)?;
         let o = self.syntax().text_range().start();
         let offsets = QuoteOffsets {
-            quotes: [offsets.quotes[0] + o, offsets.quotes[1] + o],
+            quotes: (offsets.quotes.0 + o, offsets.quotes.1 + o),
             contents: offsets.contents + o,
         };
         Some(offsets)
     }
     fn open_quote_text_range(&self) -> Option<TextRange> {
-        self.quote_offsets().map(|it| it.quotes[0])
+        self.quote_offsets().map(|it| it.quotes.0)
     }
 
     fn close_quote_text_range(&self) -> Option<TextRange> {
-        self.quote_offsets().map(|it| it.quotes[1])
+        self.quote_offsets().map(|it| it.quotes.1)
     }
 
     fn text_range_between_quotes(&self) -> Option<TextRange> {
@@ -138,11 +141,11 @@ impl HasQuotes for String {}
 impl HasQuotes for RawString {}
 
 pub trait HasStringValue: HasQuotes {
-    fn value(&self) -> Option<std::string::String>;
+    fn value(&self) -> Option<Cow<'_, str>>;
 }
 
 impl HasStringValue for String {
-    fn value(&self) -> Option<std::string::String> {
+    fn value(&self) -> Option<Cow<'_, str>> {
         let text = self.text().as_str();
         let text = &text[self.text_range_between_quotes()? - self.syntax().text_range().start()];
 
@@ -156,15 +159,17 @@ impl HasStringValue for String {
         if has_error {
             return None;
         }
-        Some(buf)
+        // FIXME: don't actually allocate for borrowed case
+        let res = if buf == text { Cow::Borrowed(text) } else { Cow::Owned(buf) };
+        Some(res)
     }
 }
 
 impl HasStringValue for RawString {
-    fn value(&self) -> Option<std::string::String> {
+    fn value(&self) -> Option<Cow<'_, str>> {
         let text = self.text().as_str();
         let text = &text[self.text_range_between_quotes()? - self.syntax().text_range().start()];
-        Some(text.to_string())
+        Some(Cow::Borrowed(text))
     }
 }
 
@@ -335,16 +340,26 @@ pub trait HasFormatSpecifier: AstToken {
                             }
                             c if c == '_' || c.is_alphabetic() => {
                                 read_identifier(&mut chars, &mut callback);
-                                if chars.peek().and_then(|next| next.1.as_ref().ok()).copied()
-                                    != Some('$')
-                                {
-                                    continue;
-                                }
-                                skip_char_and_emit(
-                                    &mut chars,
-                                    FormatSpecifier::DollarSign,
-                                    &mut callback,
-                                );
+                                // can be either width (indicated by dollar sign, or type in which case
+                                // the next sign has to be `}`)
+                                let next =
+                                    chars.peek().and_then(|next| next.1.as_ref().ok()).copied();
+                                match next {
+                                    Some('$') => skip_char_and_emit(
+                                        &mut chars,
+                                        FormatSpecifier::DollarSign,
+                                        &mut callback,
+                                    ),
+                                    Some('}') => {
+                                        skip_char_and_emit(
+                                            &mut chars,
+                                            FormatSpecifier::Close,
+                                            &mut callback,
+                                        );
+                                        continue;
+                                    }
+                                    _ => continue,
+                                };
                             }
                             _ => {}
                         }
@@ -416,17 +431,11 @@ pub trait HasFormatSpecifier: AstToken {
                         }
                     }
 
-                    let mut cloned = chars.clone().take(2);
-                    let first = cloned.next().and_then(|next| next.1.as_ref().ok()).copied();
-                    let second = cloned.next().and_then(|next| next.1.as_ref().ok()).copied();
-                    if first != Some('}') {
-                        continue;
-                    }
-                    if second == Some('}') {
-                        // Escaped format end specifier, `}}`
+                    if let Some((_, Ok('}'))) = chars.peek() {
+                        skip_char_and_emit(&mut chars, FormatSpecifier::Close, &mut callback);
+                    } else {
                         continue;
                     }
-                    skip_char_and_emit(&mut chars, FormatSpecifier::Close, &mut callback);
                 }
                 _ => {
                     while let Some((_, Ok(next_char))) = chars.peek() {
diff --git a/crates/ra_syntax/src/ast/traits.rs b/crates/ra_syntax/src/ast/traits.rs
index bfc05e08b..a8f2454fd 100644
--- a/crates/ra_syntax/src/ast/traits.rs
+++ b/crates/ra_syntax/src/ast/traits.rs
@@ -83,13 +83,22 @@ pub trait DocCommentsOwner: AstNode {
         CommentIter { iter: self.syntax().children_with_tokens() }
     }
 
+    fn doc_comment_text(&self) -> Option<String> {
+        self.doc_comments().doc_comment_text()
+    }
+}
+
+impl CommentIter {
+    pub fn from_syntax_node(syntax_node: &ast::SyntaxNode) -> CommentIter {
+        CommentIter { iter: syntax_node.children_with_tokens() }
+    }
+
     /// Returns the textual content of a doc comment block as a single string.
     /// That is, strips leading `///` (+ optional 1 character of whitespace),
     /// trailing `*/`, trailing whitespace and then joins the lines.
-    fn doc_comment_text(&self) -> Option<String> {
+    pub fn doc_comment_text(self) -> Option<String> {
         let mut has_comments = false;
         let docs = self
-            .doc_comments()
             .filter(|comment| comment.kind().doc.is_some())
             .map(|comment| {
                 has_comments = true;
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index 61e686da5..9b7664576 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -51,7 +51,8 @@ pub use crate::{
     ptr::{AstPtr, SyntaxNodePtr},
     syntax_error::SyntaxError,
     syntax_node::{
-        Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxToken, SyntaxTreeBuilder,
+        Direction, NodeOrToken, SyntaxElement, SyntaxElementChildren, SyntaxNode,
+        SyntaxNodeChildren, SyntaxToken, SyntaxTreeBuilder,
     },
 };
 pub use ra_parser::{SyntaxKind, T};
@@ -167,6 +168,41 @@ impl SourceFile {
     }
 }
 
+impl ast::Path {
+    /// Returns `text`, parsed as a path, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, ra_parser::FragmentKind::Path)
+    }
+}
+
+impl ast::Pat {
+    /// Returns `text`, parsed as a pattern, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, ra_parser::FragmentKind::Pattern)
+    }
+}
+
+impl ast::Expr {
+    /// Returns `text`, parsed as an expression, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, ra_parser::FragmentKind::Expr)
+    }
+}
+
+impl ast::ModuleItem {
+    /// Returns `text`, parsed as an item, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, ra_parser::FragmentKind::Item)
+    }
+}
+
+impl ast::TypeRef {
+    /// Returns `text`, parsed as an type reference, but only if it has no errors.
+    pub fn parse(text: &str) -> Result<Self, ()> {
+        parsing::parse_text_fragment(text, ra_parser::FragmentKind::Type)
+    }
+}
+
 /// Matches a `SyntaxNode` against an `ast` type.
 ///
 /// # Example:
diff --git a/crates/ra_syntax/src/parsing.rs b/crates/ra_syntax/src/parsing.rs
index e5eb80850..0ed3c20ef 100644
--- a/crates/ra_syntax/src/parsing.rs
+++ b/crates/ra_syntax/src/parsing.rs
@@ -6,13 +6,14 @@ mod text_token_source;
 mod text_tree_sink;
 mod reparsing;
 
-use crate::{syntax_node::GreenNode, SyntaxError};
+use crate::{syntax_node::GreenNode, AstNode, SyntaxError, SyntaxNode};
 use text_token_source::TextTokenSource;
 use text_tree_sink::TextTreeSink;
 
 pub use lexer::*;
 
 pub(crate) use self::reparsing::incremental_reparse;
+use ra_parser::SyntaxKind;
 
 pub(crate) fn parse_text(text: &str) -> (GreenNode, Vec<SyntaxError>) {
     let (tokens, lexer_errors) = tokenize(&text);
@@ -27,3 +28,32 @@ pub(crate) fn parse_text(text: &str) -> (GreenNode, Vec<SyntaxError>) {
 
     (tree, parser_errors)
 }
+
+/// Returns `text` parsed as a `T` provided there are no parse errors.
+pub(crate) fn parse_text_fragment<T: AstNode>(
+    text: &str,
+    fragment_kind: ra_parser::FragmentKind,
+) -> Result<T, ()> {
+    let (tokens, lexer_errors) = tokenize(&text);
+    if !lexer_errors.is_empty() {
+        return Err(());
+    }
+
+    let mut token_source = TextTokenSource::new(text, &tokens);
+    let mut tree_sink = TextTreeSink::new(text, &tokens);
+
+    // TextTreeSink assumes that there's at least some root node to which it can attach errors and
+    // tokens. We arbitrarily give it a SourceFile.
+    use ra_parser::TreeSink;
+    tree_sink.start_node(SyntaxKind::SOURCE_FILE);
+    ra_parser::parse_fragment(&mut token_source, &mut tree_sink, fragment_kind);
+    tree_sink.finish_node();
+
+    let (tree, parser_errors) = tree_sink.finish();
+    use ra_parser::TokenSource;
+    if !parser_errors.is_empty() || token_source.current().kind != SyntaxKind::EOF {
+        return Err(());
+    }
+
+    SyntaxNode::new_root(tree).first_child().and_then(T::cast).ok_or(())
+}
diff --git a/crates/ra_syntax/src/parsing/lexer.rs b/crates/ra_syntax/src/parsing/lexer.rs
index 1a5a6dc06..fa3be1016 100644
--- a/crates/ra_syntax/src/parsing/lexer.rs
+++ b/crates/ra_syntax/src/parsing/lexer.rs
@@ -1,6 +1,8 @@
 //! Lexer analyzes raw input string and produces lexemes (tokens).
 //! It is just a bridge to `rustc_lexer`.
 
+use rustc_lexer::{LiteralKind as LK, RawStrError};
+
 use std::convert::TryInto;
 
 use crate::{
@@ -180,8 +182,6 @@ fn rustc_token_kind_to_syntax_kind(
     return (syntax_kind, None);
 
     fn match_literal_kind(kind: &rustc_lexer::LiteralKind) -> (SyntaxKind, Option<&'static str>) {
-        use rustc_lexer::{LexRawStrError, LiteralKind as LK};
-
         #[rustfmt::skip]
         let syntax_kind = match *kind {
             LK::Int { empty_int: false, .. } => INT_NUMBER,
@@ -215,27 +215,27 @@ fn rustc_token_kind_to_syntax_kind(
                 return (BYTE_STRING, Some("Missing trailing `\"` symbol to terminate the byte string literal"))
             }
 
-            LK::RawStr(str) => match str.validate() {
-                Ok(_) => RAW_STRING,
-                Err(LexRawStrError::InvalidStarter) => return (RAW_STRING, Some("Missing `\"` symbol after `#` symbols to begin the raw string literal")),
-                Err(LexRawStrError::NoTerminator { expected, found, .. }) => if expected == found {
+            LK::RawStr { err, .. } => match err {
+                None => RAW_STRING,
+                Some(RawStrError::InvalidStarter { .. }) => return (RAW_STRING, Some("Missing `\"` symbol after `#` symbols to begin the raw string literal")),
+                Some(RawStrError::NoTerminator { expected, found, .. }) => if expected == found {
                     return (RAW_STRING, Some("Missing trailing `\"` to terminate the raw string literal"))
                 } else {
                     return (RAW_STRING, Some("Missing trailing `\"` with `#` symbols to terminate the raw string literal"))
 
                 },
-                Err(LexRawStrError::TooManyDelimiters { .. }) => return (RAW_STRING, Some("Too many `#` symbols: raw strings may be delimited by up to 65535 `#` symbols")),
+                Some(RawStrError::TooManyDelimiters { .. }) => return (RAW_STRING, Some("Too many `#` symbols: raw strings may be delimited by up to 65535 `#` symbols")),
             },
-            LK::RawByteStr(str) => match str.validate() {
-                Ok(_) => RAW_BYTE_STRING,
-                Err(LexRawStrError::InvalidStarter) => return (RAW_BYTE_STRING, Some("Missing `\"` symbol after `#` symbols to begin the raw byte string literal")),
-                Err(LexRawStrError::NoTerminator { expected, found, .. }) => if expected == found {
+            LK::RawByteStr { err, .. } => match err {
+                None => RAW_BYTE_STRING,
+                Some(RawStrError::InvalidStarter { .. }) => return (RAW_BYTE_STRING, Some("Missing `\"` symbol after `#` symbols to begin the raw byte string literal")),
+                Some(RawStrError::NoTerminator { expected, found, .. }) => if expected == found {
                     return (RAW_BYTE_STRING, Some("Missing trailing `\"` to terminate the raw byte string literal"))
                 } else {
                     return (RAW_BYTE_STRING, Some("Missing trailing `\"` with `#` symbols to terminate the raw byte string literal"))
 
                 },
-                Err(LexRawStrError::TooManyDelimiters { .. }) => return (RAW_BYTE_STRING, Some("Too many `#` symbols: raw byte strings may be delimited by up to 65535 `#` symbols")),
+                Some(RawStrError::TooManyDelimiters { .. }) => return (RAW_BYTE_STRING, Some("Too many `#` symbols: raw byte strings may be delimited by up to 65535 `#` symbols")),
             },
         };
 
diff --git a/crates/ra_syntax/src/parsing/reparsing.rs b/crates/ra_syntax/src/parsing/reparsing.rs
index edbc190f8..ed5a42ea3 100644
--- a/crates/ra_syntax/src/parsing/reparsing.rs
+++ b/crates/ra_syntax/src/parsing/reparsing.rs
@@ -120,10 +120,7 @@ fn get_text_after_edit(element: SyntaxElement, edit: &Indel) -> String {
 }
 
 fn is_contextual_kw(text: &str) -> bool {
-    match text {
-        "auto" | "default" | "union" => true,
-        _ => false,
-    }
+    matches!(text, "auto" | "default" | "union")
 }
 
 fn find_reparsable_node(node: &SyntaxNode, range: TextRange) -> Option<(SyntaxNode, Reparser)> {
diff --git a/crates/ra_syntax/src/parsing/text_token_source.rs b/crates/ra_syntax/src/parsing/text_token_source.rs
index 7ddc2c2c3..97aa3e795 100644
--- a/crates/ra_syntax/src/parsing/text_token_source.rs
+++ b/crates/ra_syntax/src/parsing/text_token_source.rs
@@ -1,40 +1,35 @@
-//! FIXME: write short doc here
+//! See `TextTokenSource` docs.
 
-use ra_parser::Token as PToken;
 use ra_parser::TokenSource;
 
 use crate::{parsing::lexer::Token, SyntaxKind::EOF, TextRange, TextSize};
 
+/// Implementation of `ra_parser::TokenSource` that takes tokens from source code text.
 pub(crate) struct TextTokenSource<'t> {
     text: &'t str,
-    /// start position of each token(expect whitespace and comment)
+    /// token and its start position (non-whitespace/comment tokens)
     /// ```non-rust
     ///  struct Foo;
-    /// ^------^---
-    /// |      |  ^-
-    /// 0      7  10
+    ///  ^------^--^-
+    ///  |      |    \________
+    ///  |      \____         \
+    ///  |           \         |
+    ///  (struct, 0) (Foo, 7) (;, 10)
     /// ```
-    /// (token, start_offset): `[(struct, 0), (Foo, 7), (;, 10)]`
-    start_offsets: Vec<TextSize>,
-    /// non-whitespace/comment tokens
-    /// ```non-rust
-    /// struct Foo {}
-    /// ^^^^^^ ^^^ ^^
-    /// ```
-    /// tokens: `[struct, Foo, {, }]`
-    tokens: Vec<Token>,
+    /// `[(struct, 0), (Foo, 7), (;, 10)]`
+    token_offset_pairs: Vec<(Token, TextSize)>,
 
     /// Current token and position
-    curr: (PToken, usize),
+    curr: (ra_parser::Token, usize),
 }
 
 impl<'t> TokenSource for TextTokenSource<'t> {
-    fn current(&self) -> PToken {
+    fn current(&self) -> ra_parser::Token {
         self.curr.0
     }
 
-    fn lookahead_nth(&self, n: usize) -> PToken {
-        mk_token(self.curr.1 + n, &self.start_offsets, &self.tokens)
+    fn lookahead_nth(&self, n: usize) -> ra_parser::Token {
+        mk_token(self.curr.1 + n, &self.token_offset_pairs)
     }
 
     fn bump(&mut self) {
@@ -43,45 +38,47 @@ impl<'t> TokenSource for TextTokenSource<'t> {
         }
 
         let pos = self.curr.1 + 1;
-        self.curr = (mk_token(pos, &self.start_offsets, &self.tokens), pos);
+        self.curr = (mk_token(pos, &self.token_offset_pairs), pos);
     }
 
     fn is_keyword(&self, kw: &str) -> bool {
-        let pos = self.curr.1;
-        if pos >= self.tokens.len() {
-            return false;
-        }
-        let range = TextRange::at(self.start_offsets[pos], self.tokens[pos].len);
-        self.text[range] == *kw
+        self.token_offset_pairs
+            .get(self.curr.1)
+            .map(|(token, offset)| &self.text[TextRange::at(*offset, token.len)] == kw)
+            .unwrap_or(false)
     }
 }
 
-fn mk_token(pos: usize, start_offsets: &[TextSize], tokens: &[Token]) -> PToken {
-    let kind = tokens.get(pos).map(|t| t.kind).unwrap_or(EOF);
-    let is_jointed_to_next = if pos + 1 < start_offsets.len() {
-        start_offsets[pos] + tokens[pos].len == start_offsets[pos + 1]
-    } else {
-        false
+fn mk_token(pos: usize, token_offset_pairs: &[(Token, TextSize)]) -> ra_parser::Token {
+    let (kind, is_jointed_to_next) = match token_offset_pairs.get(pos) {
+        Some((token, offset)) => (
+            token.kind,
+            token_offset_pairs
+                .get(pos + 1)
+                .map(|(_, next_offset)| offset + token.len == *next_offset)
+                .unwrap_or(false),
+        ),
+        None => (EOF, false),
     };
-
-    PToken { kind, is_jointed_to_next }
+    ra_parser::Token { kind, is_jointed_to_next }
 }
 
 impl<'t> TextTokenSource<'t> {
     /// Generate input from tokens(expect comment and whitespace).
     pub fn new(text: &'t str, raw_tokens: &'t [Token]) -> TextTokenSource<'t> {
-        let mut tokens = Vec::new();
-        let mut start_offsets = Vec::new();
-        let mut len = 0.into();
-        for &token in raw_tokens.iter() {
-            if !token.kind.is_trivia() {
-                tokens.push(token);
-                start_offsets.push(len);
-            }
-            len += token.len;
-        }
+        let token_offset_pairs: Vec<_> = raw_tokens
+            .iter()
+            .filter_map({
+                let mut len = 0.into();
+                move |token| {
+                    let pair = if token.kind.is_trivia() { None } else { Some((*token, len)) };
+                    len += token.len;
+                    pair
+                }
+            })
+            .collect();
 
-        let first = mk_token(0, &start_offsets, &tokens);
-        TextTokenSource { text, start_offsets, tokens, curr: (first, 0) }
+        let first = mk_token(0, &token_offset_pairs);
+        TextTokenSource { text, token_offset_pairs, curr: (first, 0) }
     }
 }
diff --git a/crates/ra_syntax/src/parsing/text_tree_sink.rs b/crates/ra_syntax/src/parsing/text_tree_sink.rs
index 22aed1db1..c6b30a02a 100644
--- a/crates/ra_syntax/src/parsing/text_tree_sink.rs
+++ b/crates/ra_syntax/src/parsing/text_tree_sink.rs
@@ -160,7 +160,10 @@ fn n_attached_trivias<'a>(
                             if let Some((peek_kind, peek_text)) =
                                 trivias.peek().map(|(_, pair)| pair)
                             {
-                                if *peek_kind == COMMENT && peek_text.starts_with("///") {
+                                if *peek_kind == COMMENT
+                                    && peek_text.starts_with("///")
+                                    && !peek_text.starts_with("////")
+                                {
                                     continue;
                                 }
                             }
diff --git a/crates/ra_syntax/src/syntax_node.rs b/crates/ra_syntax/src/syntax_node.rs
index e566af7e8..9650b8781 100644
--- a/crates/ra_syntax/src/syntax_node.rs
+++ b/crates/ra_syntax/src/syntax_node.rs
@@ -48,11 +48,11 @@ impl SyntaxTreeBuilder {
 
     pub fn finish(self) -> Parse<SyntaxNode> {
         let (green, errors) = self.finish_raw();
-        let node = SyntaxNode::new_root(green);
         if cfg!(debug_assertions) {
+            let node = SyntaxNode::new_root(green.clone());
             crate::validation::validate_block_structure(&node);
         }
-        Parse::new(node.green().clone(), errors)
+        Parse::new(green, errors)
     }
 
     pub fn token(&mut self, kind: SyntaxKind, text: SmolStr) {
diff --git a/crates/ra_syntax/src/tests.rs b/crates/ra_syntax/src/tests.rs
index aee57db62..8447dcad7 100644
--- a/crates/ra_syntax/src/tests.rs
+++ b/crates/ra_syntax/src/tests.rs
@@ -1,9 +1,12 @@
 use std::{
     fmt::Write,
-    path::{Component, Path, PathBuf},
+    fs,
+    path::{Path, PathBuf},
 };
 
-use test_utils::{collect_rust_files, dir_tests, project_dir, read_text};
+use expect::expect_file;
+use rayon::prelude::*;
+use test_utils::project_dir;
 
 use crate::{fuzz, tokenize, SourceFile, SyntaxError, TextRange, TextSize, Token};
 
@@ -55,6 +58,51 @@ fn parser_tests() {
 }
 
 #[test]
+fn expr_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/expr/ok"],
+        &["parser/fragments/expr/err"],
+        crate::ast::Expr::parse,
+    );
+}
+
+#[test]
+fn path_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/path/ok"],
+        &["parser/fragments/path/err"],
+        crate::ast::Path::parse,
+    );
+}
+
+#[test]
+fn pattern_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/pattern/ok"],
+        &["parser/fragments/pattern/err"],
+        crate::ast::Pat::parse,
+    );
+}
+
+#[test]
+fn item_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/item/ok"],
+        &["parser/fragments/item/err"],
+        crate::ast::ModuleItem::parse,
+    );
+}
+
+#[test]
+fn type_parser_tests() {
+    fragment_parser_dir_test(
+        &["parser/fragments/type/ok"],
+        &["parser/fragments/type/err"],
+        crate::ast::TypeRef::parse,
+    );
+}
+
+#[test]
 fn parser_fuzz_tests() {
     for (_, text) in collect_rust_files(&test_data_dir(), &["parser/fuzz-failures"]) {
         fuzz::check_parser(&text)
@@ -74,33 +122,43 @@ fn reparse_fuzz_tests() {
 /// FIXME: Use this as a benchmark
 #[test]
 fn self_hosting_parsing() {
-    use std::ffi::OsStr;
     let dir = project_dir().join("crates");
-    let mut count = 0;
-    for entry in walkdir::WalkDir::new(dir)
+    let files = walkdir::WalkDir::new(dir)
         .into_iter()
         .filter_entry(|entry| {
-            !entry.path().components().any(|component| {
-                // Get all files which are not in the crates/ra_syntax/test_data folder
-                component == Component::Normal(OsStr::new("test_data"))
-            })
+            // Get all files which are not in the crates/ra_syntax/test_data folder
+            !entry.path().components().any(|component| component.as_os_str() == "test_data")
         })
         .map(|e| e.unwrap())
         .filter(|entry| {
             // Get all `.rs ` files
-            !entry.path().is_dir() && (entry.path().extension() == Some(OsStr::new("rs")))
+            !entry.path().is_dir() && (entry.path().extension().unwrap_or_default() == "rs")
         })
-    {
-        count += 1;
-        let text = read_text(entry.path());
-        if let Err(errors) = SourceFile::parse(&text).ok() {
-            panic!("Parsing errors:\n{:?}\n{}\n", errors, entry.path().display());
-        }
-    }
+        .map(|entry| entry.into_path())
+        .collect::<Vec<_>>();
     assert!(
-        count > 30,
+        files.len() > 100,
         "self_hosting_parsing found too few files - is it running in the right directory?"
-    )
+    );
+
+    let errors = files
+        .into_par_iter()
+        .filter_map(|file| {
+            let text = read_text(&file);
+            match SourceFile::parse(&text).ok() {
+                Ok(_) => None,
+                Err(err) => Some((file, err)),
+            }
+        })
+        .collect::<Vec<_>>();
+
+    if !errors.is_empty() {
+        let errors = errors
+            .into_iter()
+            .map(|(path, err)| format!("{}: {:?}\n", path.display(), err))
+            .collect::<String>();
+        panic!("Parsing errors:\n{}\n", errors);
+    }
 }
 
 fn test_data_dir() -> PathBuf {
@@ -134,3 +192,89 @@ fn dump_tokens_and_errors(tokens: &[Token], errors: &[SyntaxError], text: &str)
     }
     acc
 }
+
+fn fragment_parser_dir_test<T, F>(ok_paths: &[&str], err_paths: &[&str], f: F)
+where
+    T: crate::AstNode,
+    F: Fn(&str) -> Result<T, ()>,
+{
+    dir_tests(&test_data_dir(), ok_paths, "rast", |text, path| {
+        if let Ok(node) = f(text) {
+            format!("{:#?}", crate::ast::AstNode::syntax(&node))
+        } else {
+            panic!("Failed to parse '{:?}'", path);
+        }
+    });
+    dir_tests(&test_data_dir(), err_paths, "rast", |text, path| {
+        if let Ok(_) = f(text) {
+            panic!("'{:?}' successfully parsed when it should have errored", path);
+        } else {
+            "ERROR\n".to_owned()
+        }
+    });
+}
+
+/// Calls callback `f` with input code and file paths for each `.rs` file in `test_data_dir`
+/// subdirectories defined by `paths`.
+///
+/// If the content of the matching output file differs from the output of `f()`
+/// the test will fail.
+///
+/// If there is no matching output file it will be created and filled with the
+/// output of `f()`, but the test will fail.
+fn dir_tests<F>(test_data_dir: &Path, paths: &[&str], outfile_extension: &str, f: F)
+where
+    F: Fn(&str, &Path) -> String,
+{
+    for (path, input_code) in collect_rust_files(test_data_dir, paths) {
+        let actual = f(&input_code, &path);
+        let path = path.with_extension(outfile_extension);
+        expect_file![path].assert_eq(&actual)
+    }
+}
+
+/// Collects all `.rs` files from `dir` subdirectories defined by `paths`.
+fn collect_rust_files(root_dir: &Path, paths: &[&str]) -> Vec<(PathBuf, String)> {
+    paths
+        .iter()
+        .flat_map(|path| {
+            let path = root_dir.to_owned().join(path);
+            rust_files_in_dir(&path).into_iter()
+        })
+        .map(|path| {
+            let text = read_text(&path);
+            (path, text)
+        })
+        .collect()
+}
+
+/// Collects paths to all `.rs` files from `dir` in a sorted `Vec<PathBuf>`.
+fn rust_files_in_dir(dir: &Path) -> Vec<PathBuf> {
+    let mut acc = Vec::new();
+    for file in fs::read_dir(&dir).unwrap() {
+        let file = file.unwrap();
+        let path = file.path();
+        if path.extension().unwrap_or_default() == "rs" {
+            acc.push(path);
+        }
+    }
+    acc.sort();
+    acc
+}
+
+/// Read file and normalize newlines.
+///
+/// `rustc` seems to always normalize `\r\n` newlines to `\n`:
+///
+/// ```
+/// let s = "
+/// ";
+/// assert_eq!(s.as_bytes(), &[10]);
+/// ```
+///
+/// so this should always be correct.
+fn read_text(path: &Path) -> String {
+    fs::read_to_string(path)
+        .unwrap_or_else(|_| panic!("File at {:?} should be valid", path))
+        .replace("\r\n", "\n")
+}
diff --git a/crates/ra_syntax/test_data/parser/err/0004_use_path_bad_segment.rast b/crates/ra_syntax/test_data/parser/err/0004_use_path_bad_segment.rast
index 8c6b89dc2..b3bcf472a 100644
--- a/crates/ra_syntax/test_data/parser/err/0004_use_path_bad_segment.rast
+++ b/crates/ra_syntax/test_data/parser/err/0004_use_path_bad_segment.rast
@@ -9,8 +9,7 @@ [email protected]
             [email protected]
               [email protected] "foo"
         [email protected] "::"
-        [email protected]
-          [email protected]
-            [email protected] "92"
+        [email protected]
+          [email protected] "92"
     [email protected] ";"
 error 9..9: expected identifier
diff --git a/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast b/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
index 7c957fdde..48610a5eb 100644
--- a/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
+++ b/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
@@ -180,44 +180,45 @@ [email protected]
       [email protected]
         [email protected]
           [email protected] "("
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected]
-                      [email protected] "for"
-                      [email protected]
-                        [email protected] "<"
-                      [email protected]
-                        [email protected] "\'a"
-                    [email protected] ">"
-                    [email protected] " "
+          [email protected]
+            [email protected] "for"
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "<"
+                  [email protected]
+                    [email protected] "\'a"
+                  [email protected] ">"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
                     [email protected]
                       [email protected]
                         [email protected]
                           [email protected]
                             [email protected] "Trait"
-                  [email protected] "<"
-                  [email protected]
-                    [email protected] "\'a"
-                [email protected] ">"
-                [email protected]
-                  [email protected] ")"
-              [email protected] " "
-              [email protected] "+"
-              [email protected] " "
-              [email protected]
-                [email protected] "("
-                [email protected]
-                  [email protected]
-                    [email protected]
-                      [email protected]
-                        [email protected] "Copy"
-                [email protected] ")"
-            [email protected] ">"
-            [email protected]
-              [email protected] ";"
+                    [email protected] "<"
+                    [email protected]
+                      [email protected] "\'a"
+                  [email protected] ">"
+                  [email protected]
+                    [email protected] ")"
+                [email protected] " "
+                [email protected] "+"
+                [email protected] " "
+                [email protected]
+                  [email protected] "("
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "Copy"
+                  [email protected] ")"
+              [email protected] ">"
+              [email protected]
+                [email protected] ";"
       [email protected] "\n    "
       [email protected]
         [email protected] "let"
@@ -302,13 +303,12 @@ error 146..146: expected expression
 error 147..147: expected SEMICOLON
 error 148..148: expected expression
 error 149..149: expected SEMICOLON
-error 154..154: expected pattern
-error 155..155: expected IN_KW
-error 155..155: expected expression
-error 157..157: expected a block
+error 155..155: expected type
+error 158..158: expected IN_KW
 error 165..165: expected expression
 error 168..168: expected expression
 error 179..179: expected expression
+error 180..180: expected a block
 error 180..180: expected COMMA
 error 180..180: expected expression
 error 180..180: expected R_PAREN
diff --git a/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast b/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
index 568a4cc02..4d6461d1e 100644
--- a/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
+++ b/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
@@ -12,17 +12,16 @@ [email protected]
       [email protected] "where"
       [email protected] " "
       [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
     [email protected] "\n"
     [email protected]
       [email protected] "{"
       [email protected] "}"
   [email protected] "\n"
-error 26..26: expected a path
+error 26..26: expected type
 error 26..26: expected colon
diff --git a/crates/ra_syntax/test_data/parser/err/0043_default_const.rast b/crates/ra_syntax/test_data/parser/err/0043_default_const.rast
new file mode 100644
index 000000000..8eb583ef8
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0043_default_const.rast
@@ -0,0 +1,40 @@
+[email protected]
+  [email protected]
+    [email protected] "trait"
+    [email protected] " "
+    [email protected]
+      [email protected] "T"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n  "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "default"
+      [email protected] " "
+      [email protected]
+        [email protected] "const"
+        [email protected] " "
+        [email protected]
+          [email protected] "f"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u8"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "0"
+        [email protected] ";"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+error 19..19: expected BANG
+error 19..19: expected `{`, `[`, `(`
+error 19..19: expected SEMICOLON
diff --git a/crates/ra_syntax/test_data/parser/err/0043_default_const.rs b/crates/ra_syntax/test_data/parser/err/0043_default_const.rs
new file mode 100644
index 000000000..80f15474a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0043_default_const.rs
@@ -0,0 +1,3 @@
+trait T {
+  default const f: u8 = 0;
+}
diff --git a/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast
new file mode 100644
index 000000000..cb90f28bc
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast
@@ -0,0 +1,240 @@
+[email protected]
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForRef"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "&"
+        [email protected] "\'a"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u32"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForTup"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "("
+        [email protected]
+          [email protected] "&"
+          [email protected] "\'a"
+          [email protected] " "
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "u32"
+        [email protected] ","
+        [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForSlice"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "["
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u32"
+        [email protected] "]"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForForFn"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'b"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "fn"
+          [email protected]
+            [email protected] "("
+            [email protected]
+              [email protected]
+                [email protected] "&"
+                [email protected] "\'a"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "i32"
+            [email protected] ","
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected] "&"
+                [email protected] "\'b"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "i32"
+            [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_for_for"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "for"
+          [email protected]
+            [email protected] "<"
+            [email protected]
+              [email protected] "\'b"
+            [email protected] ">"
+          [email protected] " "
+          [email protected]
+            [email protected] "for"
+            [email protected]
+              [email protected] "<"
+              [email protected]
+                [email protected] "\'c"
+              [email protected] ">"
+            [email protected] " "
+            [email protected]
+              [email protected] "fn"
+              [email protected]
+                [email protected] "("
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'a"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ","
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'b"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ","
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'c"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Copy"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+error 21..21: expected a function pointer or path
+error 52..52: expected a function pointer or path
+error 88..88: expected a function pointer or path
+error 119..119: expected a function pointer or path
+error 195..195: expected a function pointer or path
diff --git a/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs
new file mode 100644
index 000000000..0e9f8ccb4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs
@@ -0,0 +1,9 @@
+type ForRef = for<'a> &'a u32;
+type ForTup = for<'a> (&'a u32,);
+type ForSlice = for<'a> [u32];
+type ForForFn = for<'a> for<'b> fn(&'a i32, &'b i32);
+fn for_for_for<T>()
+where
+    for<'a> for<'b> for<'c> fn(&'a T, &'b T, &'c T): Copy,
+{
+}
diff --git a/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rast b/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rs b/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rs
new file mode 100644
index 000000000..ca49acb07
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/expr/err/0000_truncated_add.rs
@@ -0,0 +1 @@
+1 +
diff --git a/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rast b/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rast
new file mode 100644
index 000000000..fa78a02a6
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rast
@@ -0,0 +1,8 @@
+[email protected]
+  [email protected]
+    [email protected] "1"
+  [email protected] " "
+  [email protected] "+"
+  [email protected] " "
+  [email protected]
+    [email protected] "2"
diff --git a/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rs b/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rs
new file mode 100644
index 000000000..e0ef58402
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/expr/ok/0000_add.rs
@@ -0,0 +1 @@
+1 + 2
diff --git a/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rast b/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rs b/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rs
new file mode 100644
index 000000000..dc32389bb
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/item/err/0000_extra_keyword.rs
@@ -0,0 +1 @@
+fn fn foo() {}
diff --git a/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rast b/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rast
new file mode 100644
index 000000000..f1e78f388
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rast
@@ -0,0 +1,12 @@
+[email protected]
+  [email protected] "fn"
+  [email protected] " "
+  [email protected]
+    [email protected] "foo"
+  [email protected]
+    [email protected] "("
+    [email protected] ")"
+  [email protected] " "
+  [email protected]
+    [email protected] "{"
+    [email protected] "}"
diff --git a/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rs b/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rs
new file mode 100644
index 000000000..8f3b7ef11
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/item/ok/0000_fn.rs
@@ -0,0 +1 @@
+fn foo() {}
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rast b/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rs b/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rs
new file mode 100644
index 000000000..2046de049
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/err/0000_reserved_word.rs
@@ -0,0 +1 @@
+struct
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rast b/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rs b/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rs
new file mode 100644
index 000000000..745e8d376
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/err/0001_expression.rs
@@ -0,0 +1 @@
+a + b
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rast b/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rast
new file mode 100644
index 000000000..0c5d4360f
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rast
@@ -0,0 +1,4 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected] "foo"
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rs b/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rs
new file mode 100644
index 000000000..257cc5642
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/ok/0000_single_ident.rs
@@ -0,0 +1 @@
+foo
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rast b/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rast
new file mode 100644
index 000000000..4a2b45e6a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rast
@@ -0,0 +1,14 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected] "foo"
+    [email protected] "::"
+    [email protected]
+      [email protected]
+        [email protected] "bar"
+  [email protected] "::"
+  [email protected]
+    [email protected]
+      [email protected] "baz"
diff --git a/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rs b/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rs
new file mode 100644
index 000000000..81e0b21cd
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/path/ok/0001_multipart.rs
@@ -0,0 +1 @@
+foo::bar::baz
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rast b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rs b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rs
new file mode 100644
index 000000000..ae26fc455
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0000_reserved_word.rs
@@ -0,0 +1 @@
+fn
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rast b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rs b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rs
new file mode 100644
index 000000000..61a391d08
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/err/0001_missing_paren.rs
@@ -0,0 +1 @@
+Some(x
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rast b/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rast
new file mode 100644
index 000000000..15eb7f9c6
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rast
@@ -0,0 +1,10 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected] "Some"
+  [email protected] "("
+  [email protected]
+    [email protected]
+      [email protected] "x"
+  [email protected] ")"
diff --git a/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rs b/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rs
new file mode 100644
index 000000000..87114dd78
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/pattern/ok/0000_enum.rs
@@ -0,0 +1 @@
+Some(x)
diff --git a/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rast b/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rast
new file mode 100644
index 000000000..5df7507e2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rast
@@ -0,0 +1 @@
+ERROR
diff --git a/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rs b/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rs
new file mode 100644
index 000000000..caa4d7c09
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/type/err/0000_missing_close.rs
@@ -0,0 +1 @@
+Result<Foo, Bar
diff --git a/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rast b/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rast
new file mode 100644
index 000000000..8831cfa6c
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rast
@@ -0,0 +1,22 @@
+[email protected]
+  [email protected]
+    [email protected]
+      [email protected]
+        [email protected] "Result"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "Foo"
+        [email protected] ","
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "Bar"
+        [email protected] ">"
diff --git a/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rs b/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rs
new file mode 100644
index 000000000..b50b3bb3b
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/fragments/type/ok/0000_result.rs
@@ -0,0 +1 @@
+Result<Foo, Bar>
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.rast b/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.rast
index 0656fdf73..4e3fa704e 100644
--- a/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.rast
+++ b/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.rast
@@ -56,4 +56,3 @@ [email protected]
       [email protected] "}"
   [email protected] "\n"
 error 24..24: attributes are not allowed on BIN_EXPR
-error 44..44: attributes are not allowed on IF_EXPR
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast b/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
index 9be441110..53f7ebaf9 100644
--- a/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
+++ b/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
@@ -17,23 +17,29 @@ [email protected]
       [email protected] "{"
       [email protected] "}"
   [email protected] "\n"
-  ERROR@25..31
+  CONST_DEF@25..46
     [email protected] "unsafe"
-  [email protected] " "
-  [email protected]
+    [email protected] " "
     [email protected] "const"
     [email protected] " "
-    [email protected] "fn"
+    [email protected]
+      [email protected] "fn"
     [email protected] " "
-    [email protected]
-      [email protected] "bar"
-    [email protected]
-      [email protected] "("
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "bar"
+          [email protected]
+            [email protected] "("
+            [email protected] ")"
+  [email protected] " "
+  [email protected]
+    [email protected] "{"
+    [email protected] "}"
   [email protected] "\n"
 error 6..6: expected existential, fn, trait or impl
-error 31..31: expected existential, fn, trait or impl
+error 38..38: expected a name
+error 40..40: expected COLON
+error 46..46: expected SEMICOLON
+error 47..47: expected an item
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rast b/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rast
new file mode 100644
index 000000000..da8505607
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rast
@@ -0,0 +1,15 @@
+[email protected]
+  [email protected]
+    [email protected] "use"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "crate"
+        [email protected] "::"
+        [email protected]
+          [email protected] ";"
+  [email protected] "\n"
+error 11..11: expected identifier
+error 12..12: expected SEMICOLON
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rs b/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rs
new file mode 100644
index 000000000..7510664e1
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/err/0015_empty_segment.rs
@@ -0,0 +1 @@
+use crate::;
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
index 9dc473e43..cd0892451 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
@@ -1,61 +1,60 @@
-[email protected]9
-  FN_DEF@0..48
+SOURCE_FILE@0..54
+  FN_DEF@0..53
     [email protected] "fn"
     [email protected] " "
-    [email protected]
-      [email protected] "test"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "F"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected] ")"
-    [email protected] "\n"
-    [email protected]
-      [email protected] "where"
-      [email protected] "\n   "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "F"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Fn"
-                  [email protected]
-                    [email protected] "("
-                    [email protected]
-                      [email protected]
-                        [email protected] "&"
-                        [email protected] "\'a"
-                        [email protected] " "
-                        [email protected]
-                          [email protected]
-                            [email protected]
-                              [email protected]
-                                [email protected] "str"
-                    [email protected] ")"
-    [email protected] "\n"
-    [email protected]
-      [email protected] "{"
-      [email protected] " "
-      [email protected] "}"
-  [email protected] "\n"
+    [email protected]
+      [email protected] "for_trait"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n   "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
index b448c6178..423bc105b 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
@@ -1,4 +1,4 @@
-fn test<F>()
+fn for_trait<F>()
 where
    for<'a> F: Fn(&'a str)
 { }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
index dfb8d57ad..b26ac2d36 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
@@ -1,4 +1,4 @@
-[email protected]00
+SOURCE_FILE@0..121
   [email protected]
     [email protected] "type"
     [email protected] " "
@@ -29,212 +29,84 @@ [email protected]
             [email protected] ")"
     [email protected] ";"
   [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "foo"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected] "&"
-            [email protected] "\'a"
-            [email protected] " "
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "T"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "bar"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected] "&"
-            [email protected] "\'a"
-            [email protected] " "
-            [email protected] "mut"
-            [email protected] " "
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "T"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "baz"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "<"
-                  [email protected]
-                    [email protected] "&"
-                    [email protected] "\'a"
-                    [email protected] " "
-                    [email protected]
-                      [email protected]
-                        [email protected]
-                          [email protected]
-                            [email protected] "T"
-                  [email protected] " "
-                  [email protected] "as"
-                  [email protected] " "
-                  [email protected]
-                    [email protected]
-                      [email protected]
-                        [email protected]
-                          [email protected] "Baz"
-                  [email protected] ">"
-              [email protected] "::"
-              [email protected]
-                [email protected]
-                  [email protected] "Foo"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "B"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "unsafe"
+        [email protected] " "
+        [email protected]
+          [email protected] "extern"
+          [email protected] " "
+          [email protected] "\"C\""
+        [email protected] " "
+        [email protected] "fn"
+        [email protected]
+          [email protected] "("
+          [email protected]
+            [email protected]
+              [email protected] "&"
+              [email protected] "\'a"
+              [email protected] " "
+              [email protected]
+                [email protected] "("
+                [email protected] ")"
+          [email protected] ")"
+        [email protected] " "
+        [email protected]
+          [email protected] "->"
+          [email protected] " "
+          [email protected]
+            [email protected] "("
+            [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "Obj"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "PartialEq"
+            [email protected]
+              [email protected] "<"
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "i32"
+              [email protected] ">"
+    [email protected] ";"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
index d6774d438..8ac7b9e10 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
@@ -1,4 +1,3 @@
 type A = for<'a> fn() -> ();
-fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
-fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
-fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
+type B = for<'a> unsafe extern "C" fn(&'a ()) -> ();
+type Obj = for<'a> PartialEq<&'a i32>;
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast
new file mode 100644
index 000000000..adb6159f4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast
@@ -0,0 +1,40 @@
+[email protected]
+  [email protected]
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "T"
+    [email protected] " "
+    [email protected] "for"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "default"
+        [email protected] " "
+        [email protected] "unsafe"
+        [email protected] " "
+        [email protected] "fn"
+        [email protected] " "
+        [email protected]
+          [email protected] "foo"
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+        [email protected] " "
+        [email protected]
+          [email protected] "{"
+          [email protected] "}"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs
new file mode 100644
index 000000000..12926cd8a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs
@@ -0,0 +1,3 @@
+impl T for Foo {
+    default unsafe fn foo() {}
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast
new file mode 100644
index 000000000..a9eda5668
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast
@@ -0,0 +1,18 @@
+[email protected]
+  [email protected]
+    [email protected] "default"
+    [email protected] " "
+    [email protected] "unsafe"
+    [email protected] " "
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs
new file mode 100644
index 000000000..ba0998ff4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs
@@ -0,0 +1 @@
+default unsafe impl Foo {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast
new file mode 100644
index 000000000..868899275
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast
@@ -0,0 +1,38 @@
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "main"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected]
+        [email protected] "let"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "<"
+                [email protected]
+                  [email protected] "_"
+                [email protected] ">"
+            [email protected] "::"
+            [email protected]
+              [email protected]
+                [email protected] "Foo"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+        [email protected] ";"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs
new file mode 100644
index 000000000..ebe26834d
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs
@@ -0,0 +1 @@
+fn main() { let <_>::Foo = (); }
diff --git a/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast
new file mode 100644
index 000000000..dab0247ee
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast
@@ -0,0 +1,44 @@
+[email protected]
+  [email protected]
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "T"
+    [email protected] " "
+    [email protected] "for"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n  "
+      [email protected]
+        [email protected] "default"
+        [email protected] " "
+        [email protected] "const"
+        [email protected] " "
+        [email protected]
+          [email protected] "f"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u8"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "0"
+        [email protected] ";"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs
new file mode 100644
index 000000000..dfb3b92dc
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs
@@ -0,0 +1,3 @@
+impl T for Foo {
+  default const f: u8 = 0;
+}
diff --git a/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast
new file mode 100644
index 000000000..503585103
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast
@@ -0,0 +1,392 @@
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_trait"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_ref"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "&"
+          [email protected] "\'a"
+          [email protected] " "
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Debug"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_parens"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "("
+          [email protected]
+            [email protected] "&"
+            [email protected] "\'a"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "F"
+          [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_slice"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "["
+          [email protected]
+            [email protected] "&"
+            [email protected] "\'a"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "F"
+          [email protected] "]"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Eq"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_qpath"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "_t"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected] "&"
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "T"
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "<"
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+                [email protected] " "
+                [email protected] "as"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "Baz"
+                [email protected] ">"
+            [email protected] "::"
+            [email protected]
+              [email protected]
+                [email protected] "Foo"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Iterator"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_for_fn"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "for"
+          [email protected]
+            [email protected] "<"
+            [email protected]
+              [email protected] "\'b"
+            [email protected] ">"
+          [email protected] " "
+          [email protected]
+            [email protected] "fn"
+            [email protected]
+              [email protected] "("
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+              [email protected] ","
+              [email protected] " "
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'b"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+              [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Copy"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs
new file mode 100644
index 000000000..9058c4619
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs
@@ -0,0 +1,30 @@
+fn for_trait<F>()
+where
+    for<'a> F: Fn(&'a str),
+{
+}
+fn for_ref<F>()
+where
+    for<'a> &'a F: Debug,
+{
+}
+fn for_parens<F>()
+where
+    for<'a> (&'a F): Fn(&'a str),
+{
+}
+fn for_slice<F>()
+where
+    for<'a> [&'a F]: Eq,
+{
+}
+fn for_qpath<T>(_t: &T)
+where
+    for<'a> <&'a T as Baz>::Foo: Iterator,
+{
+}
+fn for_for_fn<T>()
+where
+    for<'a> for<'b> fn(&'a T, &'b T): Copy,
+{
+}
diff --git a/crates/ra_text_edit/Cargo.toml b/crates/ra_text_edit/Cargo.toml
index 46a2ab68f..dbb223350 100644
--- a/crates/ra_text_edit/Cargo.toml
+++ b/crates/ra_text_edit/Cargo.toml
@@ -4,6 +4,7 @@ name = "ra_text_edit"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 publish = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/ra_toolchain/Cargo.toml b/crates/ra_toolchain/Cargo.toml
index 1873fbe16..84b748c0a 100644
--- a/crates/ra_toolchain/Cargo.toml
+++ b/crates/ra_toolchain/Cargo.toml
@@ -3,6 +3,10 @@ edition = "2018"
 name = "ra_toolchain"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
 
 [dependencies]
 home = "0.5.3"
diff --git a/crates/ra_toolchain/src/lib.rs b/crates/ra_toolchain/src/lib.rs
index 3d2865e09..9916e52c4 100644
--- a/crates/ra_toolchain/src/lib.rs
+++ b/crates/ra_toolchain/src/lib.rs
@@ -15,6 +15,10 @@ pub fn rustup() -> PathBuf {
     get_path_for_executable("rustup")
 }
 
+pub fn rustfmt() -> PathBuf {
+    get_path_for_executable("rustfmt")
+}
+
 /// Return a `PathBuf` to use for the given executable.
 ///
 /// E.g., `get_path_for_executable("cargo")` may return just `cargo` if that
@@ -42,22 +46,23 @@ fn get_path_for_executable(executable_name: &'static str) -> PathBuf {
         path.push(".cargo");
         path.push("bin");
         path.push(executable_name);
-        if path.is_file() {
+        if let Some(path) = probe(path) {
             return path;
         }
     }
+
     executable_name.into()
 }
 
 fn lookup_in_path(exec: &str) -> bool {
     let paths = env::var_os("PATH").unwrap_or_default();
-    let mut candidates = env::split_paths(&paths).flat_map(|path| {
-        let candidate = path.join(&exec);
-        let with_exe = match env::consts::EXE_EXTENSION {
-            "" => None,
-            it => Some(candidate.with_extension(it)),
-        };
-        iter::once(candidate).chain(with_exe)
-    });
-    candidates.any(|it| it.is_file())
+    env::split_paths(&paths).map(|path| path.join(exec)).find_map(probe).is_some()
+}
+
+fn probe(path: PathBuf) -> Option<PathBuf> {
+    let with_extension = match env::consts::EXE_EXTENSION {
+        "" => None,
+        it => Some(path.with_extension(it)),
+    };
+    iter::once(path).chain(with_extension).find(|it| it.is_file())
 }
diff --git a/crates/ra_tt/Cargo.toml b/crates/ra_tt/Cargo.toml
index f7230a9ca..3c45248c3 100644
--- a/crates/ra_tt/Cargo.toml
+++ b/crates/ra_tt/Cargo.toml
@@ -3,11 +3,13 @@ edition = "2018"
 name = "ra_tt"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
 
 [dependencies]
+stdx = { path = "../stdx" }
 # ideally, `serde` should be enabled by `rust-analyzer`, but we enable it here
 # to reduce number of compilations
 smol_str = { version = "0.1.15", features = ["serde"] }
diff --git a/crates/ra_tt/src/buffer.rs b/crates/ra_tt/src/buffer.rs
index 5967f44cd..02c771f70 100644
--- a/crates/ra_tt/src/buffer.rs
+++ b/crates/ra_tt/src/buffer.rs
@@ -105,10 +105,7 @@ impl<'a> Eq for Cursor<'a> {}
 impl<'a> Cursor<'a> {
     /// Check whether it is eof
     pub fn eof(self) -> bool {
-        match self.buffer.entry(&self.ptr) {
-            None | Some(Entry::End(None)) => true,
-            _ => false,
-        }
+        matches!(self.buffer.entry(&self.ptr), None | Some(Entry::End(None)))
     }
 
     /// If the cursor is pointing at the end of a subtree, returns
diff --git a/crates/ra_tt/src/lib.rs b/crates/ra_tt/src/lib.rs
index 342ddbe32..8faf1cc67 100644
--- a/crates/ra_tt/src/lib.rs
+++ b/crates/ra_tt/src/lib.rs
@@ -1,24 +1,13 @@
 //! `tt` crate defines a `TokenTree` data structure: this is the interface (both
 //! input and output) of macros. It closely mirrors `proc_macro` crate's
 //! `TokenTree`.
-
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident), *) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-        )*
-    }
-}
-
 use std::{
     fmt::{self, Debug},
     panic::RefUnwindSafe,
 };
 
+use stdx::impl_from;
+
 pub use smol_str::SmolStr;
 
 /// Represents identity of the token.
@@ -41,7 +30,7 @@ pub enum TokenTree {
     Leaf(Leaf),
     Subtree(Subtree),
 }
-impl_froms!(TokenTree: Leaf, Subtree);
+impl_from!(Leaf, Subtree for TokenTree);
 
 impl TokenTree {
     pub fn empty() -> Self {
@@ -55,7 +44,7 @@ pub enum Leaf {
     Punct(Punct),
     Ident(Ident),
 }
-impl_froms!(Leaf: Literal, Punct, Ident);
+impl_from!(Literal, Punct, Ident for Leaf);
 
 #[derive(Clone, PartialEq, Eq, Hash, Default)]
 pub struct Subtree {
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 65b487db3..3ed2a689e 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -4,13 +4,14 @@ name = "rust-analyzer"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 autobins = false
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
 
 [[bin]]
 name = "rust-analyzer"
-path = "./src/bin/main.rs"
+path = "src/bin/main.rs"
 
 [dependencies]
 anyhow = "1.0.26"
@@ -20,30 +21,34 @@ globset = "0.4.4"
 itertools = "0.9.0"
 jod-thread = "0.1.0"
 log = "0.4.8"
-lsp-types = { version = "0.74.0", features = ["proposed"] }
-parking_lot = "0.10.0"
+lsp-types = { version = "0.77.0", features = ["proposed"] }
+parking_lot = "0.11.0"
 pico-args = "0.3.1"
 rand = { version = "0.7.3", features = ["small_rng"] }
-relative-path = "1.0.0"
 rustc-hash = "1.1.0"
 serde = { version = "1.0.106", features = ["derive"] }
 serde_json = "1.0.48"
 threadpool = "1.7.1"
+rayon = "1.3.1"
 
 stdx = { path = "../stdx" }
 
-lsp-server = "0.3.1"
-ra_flycheck = { path = "../ra_flycheck" }
+lsp-server = "0.3.3"
+flycheck = { path = "../flycheck" }
 ra_ide = { path = "../ra_ide" }
 ra_prof = { path = "../ra_prof" }
 ra_project_model = { path = "../ra_project_model" }
 ra_syntax = { path = "../ra_syntax" }
 ra_text_edit = { path = "../ra_text_edit" }
-ra_vfs = "0.6.0"
+vfs = { path = "../vfs" }
+vfs-notify = { path = "../vfs-notify" }
 ra_cfg = { path = "../ra_cfg"}
+ra_toolchain = { path = "../ra_toolchain" }
 
 # This should only be used in CLI
 ra_db = { path = "../ra_db" }
+ra_ide_db = { path = "../ra_ide_db" }
+ra_ssr = { path = "../ra_ssr" }
 hir = { path = "../ra_hir", package = "ra_hir" }
 hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
 hir_ty = { path = "../ra_hir_ty", package = "ra_hir_ty" }
@@ -54,10 +59,11 @@ winapi = "0.3.8"
 
 [dev-dependencies]
 tempfile = "3.1.0"
-insta = "0.16.0"
+expect = { path = "../expect" }
 test_utils = { path = "../test_utils" }
 mbe = { path = "../ra_mbe", package = "ra_mbe" }
 tt = { path = "../ra_tt", package = "ra_tt" }
 
 [features]
 jemalloc = [ "ra_prof/jemalloc" ]
+mimalloc = [ "ra_prof/mimalloc" ]
diff --git a/crates/rust-analyzer/build.rs b/crates/rust-analyzer/build.rs
index d4b010c04..5ae76ba30 100644
--- a/crates/rust-analyzer/build.rs
+++ b/crates/rust-analyzer/build.rs
@@ -5,11 +5,14 @@ use std::{env, path::PathBuf, process::Command};
 fn main() {
     set_rerun();
 
-    let rev = rev().unwrap_or_else(|| "???????".to_string());
+    let rev =
+        env::var("RUST_ANALYZER_REV").ok().or_else(rev).unwrap_or_else(|| "???????".to_string());
     println!("cargo:rustc-env=REV={}", rev)
 }
 
 fn set_rerun() {
+    println!("cargo:rerun-if-env-changed=RUST_ANALYZER_REV");
+
     let mut manifest_dir = PathBuf::from(
         env::var("CARGO_MANIFEST_DIR").expect("`CARGO_MANIFEST_DIR` is always set by cargo."),
     );
diff --git a/crates/rust-analyzer/src/bin/args.rs b/crates/rust-analyzer/src/bin/args.rs
index 8e3ca9343..3210416ee 100644
--- a/crates/rust-analyzer/src/bin/args.rs
+++ b/crates/rust-analyzer/src/bin/args.rs
@@ -3,11 +3,13 @@
 //! If run started args, we run the LSP server loop. With a subcommand, we do a
 //! one-time batch processing.
 
+use std::{env, fmt::Write, path::PathBuf};
+
 use anyhow::{bail, Result};
 use pico_args::Arguments;
+use ra_ssr::{SsrPattern, SsrRule};
 use rust_analyzer::cli::{BenchWhat, Position, Verbosity};
-
-use std::{fmt::Write, path::PathBuf};
+use vfs::AbsPathBuf;
 
 pub(crate) struct Args {
     pub(crate) verbosity: Verbosity,
@@ -24,6 +26,7 @@ pub(crate) enum Command {
     },
     Stats {
         randomize: bool,
+        parallel: bool,
         memory_usage: bool,
         only: Option<String>,
         with_deps: bool,
@@ -32,6 +35,7 @@ pub(crate) enum Command {
         with_proc_macro: bool,
     },
     Bench {
+        memory_usage: bool,
         path: PathBuf,
         what: BenchWhat,
         load_output_dirs: bool,
@@ -45,6 +49,13 @@ pub(crate) enum Command {
         /// this would include the parser test files.
         all: bool,
     },
+    Ssr {
+        rules: Vec<SsrRule>,
+    },
+    StructuredSearch {
+        debug_snippet: Option<String>,
+        patterns: Vec<SsrPattern>,
+    },
     ProcMacro,
     RunServer,
     Version,
@@ -94,7 +105,7 @@ USAGE:
     rust-analyzer parse [FLAGS]
 
 FLAGS:
-    -h, --help       Prints help inforamtion
+    -h, --help       Prints help information
         --no-dump"
                     );
                     return Ok(Err(HelpPrinted));
@@ -153,10 +164,14 @@ USAGE:
     rust-analyzer analysis-stats [FLAGS] [OPTIONS] [PATH]
 
 FLAGS:
+    -o, --only              Only analyze items matching this path
     -h, --help              Prints help information
-        --memory-usage
+        --memory-usage      Collect memory usage statistics (requires `--features jemalloc`)
+        --randomize         Randomize order in which crates, modules, and items are processed
+        --parallel          Run type inference in parallel
         --load-output-dirs  Load OUT_DIR values by running `cargo check` before analysis
-        --with-proc-macro    Use ra-proc-macro-srv for proc-macro expanding
+        --with-proc-macro   Use ra-proc-macro-srv for proc-macro expanding
+        --with-deps         Also analyze all dependencies
     -v, --verbose
     -q, --quiet
 
@@ -170,6 +185,7 @@ ARGS:
                 }
 
                 let randomize = matches.contains("--randomize");
+                let parallel = matches.contains("--parallel");
                 let memory_usage = matches.contains("--memory-usage");
                 let only: Option<String> = matches.opt_value_from_str(["-o", "--only"])?;
                 let with_deps: bool = matches.contains("--with-deps");
@@ -185,6 +201,7 @@ ARGS:
 
                 Command::Stats {
                     randomize,
+                    parallel,
                     memory_usage,
                     only,
                     with_deps,
@@ -204,8 +221,9 @@ USAGE:
 
 FLAGS:
     -h, --help          Prints help information
+    --memory-usage      Collect memory usage statistics (requires `--features jemalloc`)
     --load-output-dirs  Load OUT_DIR values by running `cargo check` before analysis
-    --with-proc-macro    Use ra-proc-macro-srv for proc-macro expanding
+    --with-proc-macro   Use ra-proc-macro-srv for proc-macro expanding
     -v, --verbose
 
 OPTIONS:
@@ -225,16 +243,20 @@ ARGS:
                 let complete_path: Option<Position> = matches.opt_value_from_str("--complete")?;
                 let goto_def_path: Option<Position> = matches.opt_value_from_str("--goto-def")?;
                 let what = match (highlight_path, complete_path, goto_def_path) {
-                    (Some(path), None, None) => BenchWhat::Highlight { path: path.into() },
+                    (Some(path), None, None) => {
+                        let path = env::current_dir().unwrap().join(path);
+                        BenchWhat::Highlight { path: AbsPathBuf::assert(path) }
+                    }
                     (None, Some(position), None) => BenchWhat::Complete(position),
                     (None, None, Some(position)) => BenchWhat::GotoDef(position),
                     _ => panic!(
                         "exactly one of  `--highlight`, `--complete` or `--goto-def` must be set"
                     ),
                 };
+                let memory_usage = matches.contains("--memory-usage");
                 let load_output_dirs = matches.contains("--load-output-dirs");
                 let with_proc_macro = matches.contains("--with-proc-macro");
-                Command::Bench { path, what, load_output_dirs, with_proc_macro }
+                Command::Bench { memory_usage, path, what, load_output_dirs, with_proc_macro }
             }
             "diagnostics" => {
                 if matches.contains(["-h", "--help"]) {
@@ -270,6 +292,61 @@ ARGS:
                 Command::Diagnostics { path, load_output_dirs, with_proc_macro, all }
             }
             "proc-macro" => Command::ProcMacro,
+            "ssr" => {
+                if matches.contains(["-h", "--help"]) {
+                    eprintln!(
+                        "\
+rust-analyzer ssr
+
+USAGE:
+    rust-analyzer ssr [FLAGS] [RULE...]
+
+EXAMPLE:
+    rust-analyzer ssr '$a.foo($b) ==> bar($a, $b)'
+
+FLAGS:
+    --debug <snippet>   Prints debug information for any nodes with source exactly equal to <snippet>
+    -h, --help          Prints help information
+
+ARGS:
+    <RULE>              A structured search replace rule"
+                    );
+                    return Ok(Err(HelpPrinted));
+                }
+                let mut rules = Vec::new();
+                while let Some(rule) = matches.free_from_str()? {
+                    rules.push(rule);
+                }
+                Command::Ssr { rules }
+            }
+            "search" => {
+                if matches.contains(["-h", "--help"]) {
+                    eprintln!(
+                        "\
+rust-analyzer search
+
+USAGE:
+    rust-analyzer search [FLAGS] [PATTERN...]
+
+EXAMPLE:
+    rust-analyzer search '$a.foo($b)'
+
+FLAGS:
+    --debug <snippet>   Prints debug information for any nodes with source exactly equal to <snippet>
+    -h, --help          Prints help information
+
+ARGS:
+    <PATTERN>           A structured search pattern"
+                    );
+                    return Ok(Err(HelpPrinted));
+                }
+                let debug_snippet = matches.opt_value_from_str("--debug")?;
+                let mut patterns = Vec::new();
+                while let Some(rule) = matches.free_from_str()? {
+                    patterns.push(rule);
+                }
+                Command::StructuredSearch { patterns, debug_snippet }
+            }
             _ => {
                 print_subcommands();
                 return Ok(Err(HelpPrinted));
@@ -297,6 +374,8 @@ SUBCOMMANDS:
     diagnostics
     proc-macro
     parse
+    search
+    ssr
     symbols"
     )
 }
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index e82fd57de..408892eab 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -3,8 +3,16 @@
 //! Based on cli flags, either spawns an LSP server, or runs a batch analysis
 mod args;
 
+use std::convert::TryFrom;
+
 use lsp_server::Connection;
-use rust_analyzer::{cli, config::Config, from_json, Result};
+use ra_project_model::ProjectManifest;
+use rust_analyzer::{
+    cli,
+    config::{Config, LinkedProject},
+    from_json, Result,
+};
+use vfs::AbsPathBuf;
 
 use crate::args::HelpPrinted;
 
@@ -15,11 +23,15 @@ fn main() -> Result<()> {
         Err(HelpPrinted) => return Ok(()),
     };
     match args.command {
+        args::Command::RunServer => run_server()?,
+        args::Command::ProcMacro => ra_proc_macro_srv::cli::run()?,
+
         args::Command::Parse { no_dump } => cli::parse(no_dump)?,
         args::Command::Symbols => cli::symbols()?,
         args::Command::Highlight { rainbow } => cli::highlight(rainbow)?,
         args::Command::Stats {
             randomize,
+            parallel,
             memory_usage,
             only,
             with_deps,
@@ -33,26 +45,29 @@ fn main() -> Result<()> {
             only.as_ref().map(String::as_ref),
             with_deps,
             randomize,
+            parallel,
             load_output_dirs,
             with_proc_macro,
         )?,
-
-        args::Command::Bench { path, what, load_output_dirs, with_proc_macro } => {
+        args::Command::Bench { memory_usage, path, what, load_output_dirs, with_proc_macro } => {
             cli::analysis_bench(
                 args.verbosity,
                 path.as_ref(),
                 what,
+                memory_usage,
                 load_output_dirs,
                 with_proc_macro,
             )?
         }
-
         args::Command::Diagnostics { path, load_output_dirs, with_proc_macro, all } => {
             cli::diagnostics(path.as_ref(), load_output_dirs, with_proc_macro, all)?
         }
-
-        args::Command::ProcMacro => run_proc_macro_srv()?,
-        args::Command::RunServer => run_server()?,
+        args::Command::Ssr { rules } => {
+            cli::apply_ssr_rules(rules)?;
+        }
+        args::Command::StructuredSearch { patterns, debug_snippet } => {
+            cli::search_for_patterns(patterns, debug_snippet)?;
+        }
         args::Command::Version => println!("rust-analyzer {}", env!("REV")),
     }
     Ok(())
@@ -65,11 +80,6 @@ fn setup_logging() -> Result<()> {
     Ok(())
 }
 
-fn run_proc_macro_srv() -> Result<()> {
-    ra_proc_macro_srv::cli::run()?;
-    Ok(())
-}
-
 fn run_server() -> Result<()> {
     log::info!("lifecycle: server started");
 
@@ -97,28 +107,48 @@ fn run_server() -> Result<()> {
         log::info!("Client '{}' {}", client_info.name, client_info.version.unwrap_or_default());
     }
 
-    let cwd = std::env::current_dir()?;
-    let root = initialize_params.root_uri.and_then(|it| it.to_file_path().ok()).unwrap_or(cwd);
-
-    let workspace_roots = initialize_params
-        .workspace_folders
-        .map(|workspaces| {
-            workspaces.into_iter().filter_map(|it| it.uri.to_file_path().ok()).collect::<Vec<_>>()
-        })
-        .filter(|workspaces| !workspaces.is_empty())
-        .unwrap_or_else(|| vec![root]);
-
     let config = {
-        let mut config = Config::default();
-        if let Some(value) = &initialize_params.initialization_options {
-            config.update(value);
+        let root_path = match initialize_params
+            .root_uri
+            .and_then(|it| it.to_file_path().ok())
+            .and_then(|it| AbsPathBuf::try_from(it).ok())
+        {
+            Some(it) => it,
+            None => {
+                let cwd = std::env::current_dir()?;
+                AbsPathBuf::assert(cwd)
+            }
+        };
+
+        let mut config = Config::new(root_path);
+        if let Some(json) = initialize_params.initialization_options {
+            config.update(json);
         }
         config.update_caps(&initialize_params.capabilities);
 
+        if config.linked_projects.is_empty() {
+            let workspace_roots = initialize_params
+                .workspace_folders
+                .map(|workspaces| {
+                    workspaces
+                        .into_iter()
+                        .filter_map(|it| it.uri.to_file_path().ok())
+                        .filter_map(|it| AbsPathBuf::try_from(it).ok())
+                        .collect::<Vec<_>>()
+                })
+                .filter(|workspaces| !workspaces.is_empty())
+                .unwrap_or_else(|| vec![config.root_path.clone()]);
+
+            config.linked_projects = ProjectManifest::discover_all(&workspace_roots)
+                .into_iter()
+                .map(LinkedProject::from)
+                .collect();
+        }
+
         config
     };
 
-    rust_analyzer::main_loop(workspace_roots, config, connection)?;
+    rust_analyzer::main_loop(config, connection)?;
 
     log::info!("shutting down IO...");
     io_threads.join()?;
diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index 345693524..37d695448 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -2,9 +2,9 @@
 use std::env;
 
 use lsp_types::{
-    CallHierarchyServerCapability, ClientCapabilities, CodeActionOptions,
+    CallHierarchyServerCapability, ClientCapabilities, CodeActionKind, CodeActionOptions,
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
-    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability,
+    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability, HoverProviderCapability,
     ImplementationProviderCapability, RenameOptions, RenameProviderCapability, SaveOptions,
     SelectionRangeProviderCapability, SemanticTokensDocumentProvider, SemanticTokensLegend,
     SemanticTokensOptions, ServerCapabilities, SignatureHelpOptions, TextDocumentSyncCapability,
@@ -28,9 +28,9 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
             }),
             will_save: None,
             will_save_wait_until: None,
-            save: Some(SaveOptions::default()),
+            save: Some(SaveOptions::default().into()),
         })),
-        hover_provider: Some(true),
+        hover_provider: Some(HoverProviderCapability::Simple(true)),
         completion_provider: Some(CompletionOptions {
             resolve_provider: None,
             trigger_characters: Some(vec![":".to_string(), ".".to_string()]),
@@ -87,6 +87,9 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
             "ssr": true,
             "onEnter": true,
             "parentModule": true,
+            "runnables": {
+                "kinds": [ "cargo" ],
+            },
         })),
     }
 }
@@ -103,14 +106,12 @@ fn code_action_capabilities(client_caps: &ClientCapabilities) -> CodeActionProvi
                 // Ideally we would base this off of the client capabilities
                 // but the client is supposed to fall back gracefully for unknown values.
                 code_action_kinds: Some(vec![
-                    lsp_types::code_action_kind::EMPTY.to_string(),
-                    lsp_types::code_action_kind::QUICKFIX.to_string(),
-                    lsp_types::code_action_kind::REFACTOR.to_string(),
-                    lsp_types::code_action_kind::REFACTOR_EXTRACT.to_string(),
-                    lsp_types::code_action_kind::REFACTOR_INLINE.to_string(),
-                    lsp_types::code_action_kind::REFACTOR_REWRITE.to_string(),
-                    lsp_types::code_action_kind::SOURCE.to_string(),
-                    lsp_types::code_action_kind::SOURCE_ORGANIZE_IMPORTS.to_string(),
+                    CodeActionKind::EMPTY,
+                    CodeActionKind::QUICKFIX,
+                    CodeActionKind::REFACTOR,
+                    CodeActionKind::REFACTOR_EXTRACT,
+                    CodeActionKind::REFACTOR_INLINE,
+                    CodeActionKind::REFACTOR_REWRITE,
                 ]),
                 work_done_progress_options: Default::default(),
             })
diff --git a/crates/rust-analyzer/src/cargo_target_spec.rs b/crates/rust-analyzer/src/cargo_target_spec.rs
index 441fb61df..318399624 100644
--- a/crates/rust-analyzer/src/cargo_target_spec.rs
+++ b/crates/rust-analyzer/src/cargo_target_spec.rs
@@ -1,10 +1,11 @@
 //! See `CargoTargetSpec`
 
+use ra_cfg::CfgExpr;
 use ra_ide::{FileId, RunnableKind, TestId};
-use ra_project_model::{self, ProjectWorkspace, TargetKind};
+use ra_project_model::{self, TargetKind};
+use vfs::AbsPathBuf;
 
-use crate::{world::WorldSnapshot, Result};
-use ra_syntax::SmolStr;
+use crate::{global_state::GlobalStateSnapshot, Result};
 
 /// Abstract representation of Cargo target.
 ///
@@ -12,6 +13,7 @@ use ra_syntax::SmolStr;
 /// build/test/run the target.
 #[derive(Clone)]
 pub(crate) struct CargoTargetSpec {
+    pub(crate) workspace_root: AbsPathBuf,
     pub(crate) package: String,
     pub(crate) target: String,
     pub(crate) target_kind: TargetKind,
@@ -19,9 +21,10 @@ pub(crate) struct CargoTargetSpec {
 
 impl CargoTargetSpec {
     pub(crate) fn runnable_args(
+        snap: &GlobalStateSnapshot,
         spec: Option<CargoTargetSpec>,
         kind: &RunnableKind,
-        features_needed: &Vec<SmolStr>,
+        cfgs: &[CfgExpr],
     ) -> Result<(Vec<String>, Vec<String>)> {
         let mut args = Vec::new();
         let mut extra_args = Vec::new();
@@ -76,36 +79,45 @@ impl CargoTargetSpec {
             }
         }
 
-        features_needed.iter().for_each(|feature| {
-            args.push("--features".to_string());
-            args.push(feature.to_string());
-        });
+        if snap.config.cargo.all_features {
+            args.push("--all-features".to_string());
+        } else {
+            let mut features = Vec::new();
+            for cfg in cfgs {
+                required_features(cfg, &mut features);
+            }
+            for feature in &snap.config.cargo.features {
+                features.push(feature.clone());
+            }
+            features.dedup();
+            for feature in features {
+                args.push("--features".to_string());
+                args.push(feature);
+            }
+        }
 
         Ok((args, extra_args))
     }
 
     pub(crate) fn for_file(
-        world: &WorldSnapshot,
+        global_state_snapshot: &GlobalStateSnapshot,
         file_id: FileId,
     ) -> Result<Option<CargoTargetSpec>> {
-        let &crate_id = match world.analysis().crate_for(file_id)?.first() {
-            Some(crate_id) => crate_id,
+        let crate_id = match global_state_snapshot.analysis.crate_for(file_id)?.first() {
+            Some(crate_id) => *crate_id,
             None => return Ok(None),
         };
-        let file_id = world.analysis().crate_root(crate_id)?;
-        let path = world.file_id_to_path(file_id);
-        let res = world.workspaces.iter().find_map(|ws| match ws {
-            ProjectWorkspace::Cargo { cargo, .. } => {
-                let tgt = cargo.target_by_root(&path)?;
-                Some(CargoTargetSpec {
-                    package: cargo.package_flag(&cargo[cargo[tgt].package]),
-                    target: cargo[tgt].name.clone(),
-                    target_kind: cargo[tgt].kind,
-                })
-            }
-            ProjectWorkspace::Json { .. } => None,
-        });
-        Ok(res)
+        let (cargo_ws, target) = match global_state_snapshot.cargo_target_for_crate_root(crate_id) {
+            Some(it) => it,
+            None => return Ok(None),
+        };
+        let res = CargoTargetSpec {
+            workspace_root: cargo_ws.workspace_root().to_path_buf(),
+            package: cargo_ws.package_flag(&cargo_ws[cargo_ws[target].package]),
+            target: cargo_ws[target].name.clone(),
+            target_kind: cargo_ws[target].kind,
+        };
+        Ok(Some(res))
     }
 
     pub(crate) fn push_to(self, buf: &mut Vec<String>, kind: &RunnableKind) {
@@ -140,3 +152,74 @@ impl CargoTargetSpec {
         }
     }
 }
+
+/// Fill minimal features needed
+fn required_features(cfg_expr: &CfgExpr, features: &mut Vec<String>) {
+    match cfg_expr {
+        CfgExpr::KeyValue { key, value } if key == "feature" => features.push(value.to_string()),
+        CfgExpr::All(preds) => {
+            preds.iter().for_each(|cfg| required_features(cfg, features));
+        }
+        CfgExpr::Any(preds) => {
+            for cfg in preds {
+                let len_features = features.len();
+                required_features(cfg, features);
+                if len_features != features.len() {
+                    break;
+                }
+            }
+        }
+        _ => {}
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use mbe::{ast_to_token_tree, TokenMap};
+    use ra_cfg::parse_cfg;
+    use ra_syntax::{
+        ast::{self, AstNode},
+        SmolStr,
+    };
+
+    fn get_token_tree_generated(input: &str) -> (tt::Subtree, TokenMap) {
+        let source_file = ast::SourceFile::parse(input).ok().unwrap();
+        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+        ast_to_token_tree(&tt).unwrap()
+    }
+
+    #[test]
+    fn test_cfg_expr_minimal_features_needed() {
+        let (subtree, _) = get_token_tree_generated(r#"#![cfg(feature = "baz")]"#);
+        let cfg_expr = parse_cfg(&subtree);
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+
+        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+
+        let (subtree, _) =
+            get_token_tree_generated(r#"#![cfg(all(feature = "baz", feature = "foo"))]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert_eq!(min_features, vec![SmolStr::new("baz"), SmolStr::new("foo")]);
+
+        let (subtree, _) =
+            get_token_tree_generated(r#"#![cfg(any(feature = "baz", feature = "foo", unix))]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+
+        let (subtree, _) = get_token_tree_generated(r#"#![cfg(foo)]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert!(min_features.is_empty());
+    }
+}
diff --git a/crates/rust-analyzer/src/cli.rs b/crates/rust-analyzer/src/cli.rs
index 39ce77900..6863f100b 100644
--- a/crates/rust-analyzer/src/cli.rs
+++ b/crates/rust-analyzer/src/cli.rs
@@ -5,6 +5,7 @@ mod analysis_stats;
 mod analysis_bench;
 mod diagnostics;
 mod progress_report;
+mod ssr;
 
 use std::io::Read;
 
@@ -17,6 +18,7 @@ pub use analysis_bench::{analysis_bench, BenchWhat, Position};
 pub use analysis_stats::analysis_stats;
 pub use diagnostics::diagnostics;
 pub use load_cargo::load_cargo;
+pub use ssr::{apply_ssr_rules, search_for_patterns};
 
 #[derive(Clone, Copy)]
 pub enum Verbosity {
@@ -28,16 +30,10 @@ pub enum Verbosity {
 
 impl Verbosity {
     pub fn is_verbose(self) -> bool {
-        match self {
-            Verbosity::Verbose | Verbosity::Spammy => true,
-            _ => false,
-        }
+        matches!(self, Verbosity::Verbose | Verbosity::Spammy)
     }
     pub fn is_spammy(self) -> bool {
-        match self {
-            Verbosity::Spammy => true,
-            _ => false,
-        }
+        matches!(self, Verbosity::Spammy)
     }
 }
 
diff --git a/crates/rust-analyzer/src/cli/analysis_bench.rs b/crates/rust-analyzer/src/cli/analysis_bench.rs
index b20efe98d..9299879b7 100644
--- a/crates/rust-analyzer/src/cli/analysis_bench.rs
+++ b/crates/rust-analyzer/src/cli/analysis_bench.rs
@@ -1,29 +1,28 @@
 //! Benchmark operations like highlighting or goto definition.
 
-use std::{
-    path::{Path, PathBuf},
-    str::FromStr,
-    sync::Arc,
-    time::Instant,
-};
+use std::{env, path::Path, str::FromStr, sync::Arc, time::Instant};
 
 use anyhow::{format_err, Result};
 use ra_db::{
     salsa::{Database, Durability},
-    FileId, SourceDatabaseExt,
+    FileId,
 };
 use ra_ide::{Analysis, AnalysisChange, AnalysisHost, CompletionConfig, FilePosition, LineCol};
+use vfs::AbsPathBuf;
 
-use crate::cli::{load_cargo::load_cargo, Verbosity};
+use crate::{
+    cli::{load_cargo::load_cargo, Verbosity},
+    print_memory_usage,
+};
 
 pub enum BenchWhat {
-    Highlight { path: PathBuf },
+    Highlight { path: AbsPathBuf },
     Complete(Position),
     GotoDef(Position),
 }
 
 pub struct Position {
-    pub path: PathBuf,
+    pub path: AbsPathBuf,
     pub line: u32,
     pub column: u32,
 }
@@ -33,7 +32,9 @@ impl FromStr for Position {
     fn from_str(s: &str) -> Result<Self> {
         let (path_line, column) = rsplit_at_char(s, ':')?;
         let (path, line) = rsplit_at_char(path_line, ':')?;
-        Ok(Position { path: path.into(), line: line.parse()?, column: column.parse()? })
+        let path = env::current_dir().unwrap().join(path);
+        let path = AbsPathBuf::assert(path);
+        Ok(Position { path, line: line.parse()?, column: column.parse()? })
     }
 }
 
@@ -46,6 +47,7 @@ pub fn analysis_bench(
     verbosity: Verbosity,
     path: &Path,
     what: BenchWhat,
+    memory_usage: bool,
     load_output_dirs: bool,
     with_proc_macro: bool,
 ) -> Result<()> {
@@ -53,8 +55,7 @@ pub fn analysis_bench(
 
     let start = Instant::now();
     eprint!("loading: ");
-    let (mut host, roots) = load_cargo(path, load_output_dirs, with_proc_macro)?;
-    let db = host.raw_database();
+    let (mut host, vfs) = load_cargo(path, load_output_dirs, with_proc_macro)?;
     eprintln!("{:?}\n", start.elapsed());
 
     let file_id = {
@@ -62,22 +63,8 @@ pub fn analysis_bench(
             BenchWhat::Highlight { path } => path,
             BenchWhat::Complete(pos) | BenchWhat::GotoDef(pos) => &pos.path,
         };
-        let path = std::env::current_dir()?.join(path).canonicalize()?;
-        roots
-            .iter()
-            .find_map(|(source_root_id, project_root)| {
-                if project_root.is_member() {
-                    for file_id in db.source_root(*source_root_id).walk() {
-                        let rel_path = db.file_relative_path(file_id);
-                        let abs_path = rel_path.to_path(project_root.path());
-                        if abs_path == path {
-                            return Some(file_id);
-                        }
-                    }
-                }
-                None
-            })
-            .ok_or_else(|| format_err!("Can't find {}", path.display()))?
+        let path = path.clone().into();
+        vfs.file_id(&path).ok_or_else(|| format_err!("Can't find {}", path))?
     };
 
     match &what {
@@ -91,10 +78,7 @@ pub fn analysis_bench(
             }
         }
         BenchWhat::Complete(pos) | BenchWhat::GotoDef(pos) => {
-            let is_completion = match what {
-                BenchWhat::Complete(..) => true,
-                _ => false,
-            };
+            let is_completion = matches!(what, BenchWhat::Complete(..));
 
             let offset = host
                 .analysis()
@@ -119,6 +103,11 @@ pub fn analysis_bench(
             }
         }
     }
+
+    if memory_usage {
+        print_memory_usage(host, vfs);
+    }
+
     Ok(())
 }
 
@@ -149,7 +138,20 @@ fn do_work<F: Fn(&Analysis) -> T, T>(host: &mut AnalysisHost, file_id: FileId, w
             let mut text = host.analysis().file_text(file_id).unwrap().to_string();
             text.push_str("\n/* Hello world */\n");
             let mut change = AnalysisChange::new();
-            change.change_file(file_id, Arc::new(text));
+            change.change_file(file_id, Some(Arc::new(text)));
+            host.apply_change(change);
+        }
+        work(&host.analysis());
+        eprintln!("{:?}", start.elapsed());
+    }
+    {
+        let start = Instant::now();
+        eprint!("item change:    ");
+        {
+            let mut text = host.analysis().file_text(file_id).unwrap().to_string();
+            text.push_str("\npub fn _dummy() {}\n");
+            let mut change = AnalysisChange::new();
+            change.change_file(file_id, Some(Arc::new(text)));
             host.apply_change(change);
         }
         work(&host.analysis());
diff --git a/crates/rust-analyzer/src/cli/analysis_stats.rs b/crates/rust-analyzer/src/cli/analysis_stats.rs
index 72183da15..ddb3db6c3 100644
--- a/crates/rust-analyzer/src/cli/analysis_stats.rs
+++ b/crates/rust-analyzer/src/cli/analysis_stats.rs
@@ -1,7 +1,12 @@
 //! Fully type-check project and print various stats, like the number of type
 //! errors.
 
-use std::{collections::HashSet, path::Path, time::Instant};
+use std::{path::Path, time::Instant};
+
+use itertools::Itertools;
+use rand::{seq::SliceRandom, thread_rng};
+use rayon::prelude::*;
+use rustc_hash::FxHashSet;
 
 use hir::{
     db::{AstDatabase, DefDatabase, HirDatabase},
@@ -9,13 +14,25 @@ use hir::{
 };
 use hir_def::FunctionId;
 use hir_ty::{Ty, TypeWalk};
-use itertools::Itertools;
-use ra_db::SourceDatabaseExt;
+use ra_db::{
+    salsa::{self, ParallelDatabase},
+    SourceDatabaseExt,
+};
 use ra_syntax::AstNode;
-use rand::{seq::SliceRandom, thread_rng};
 use stdx::format_to;
 
-use crate::cli::{load_cargo::load_cargo, progress_report::ProgressReport, Result, Verbosity};
+use crate::{
+    cli::{load_cargo::load_cargo, progress_report::ProgressReport, Result, Verbosity},
+    print_memory_usage,
+};
+
+/// Need to wrap Snapshot to provide `Clone` impl for `map_with`
+struct Snap<DB>(DB);
+impl<DB: ParallelDatabase> Clone for Snap<salsa::Snapshot<DB>> {
+    fn clone(&self) -> Snap<salsa::Snapshot<DB>> {
+        Snap(self.0.snapshot())
+    }
+}
 
 pub fn analysis_stats(
     verbosity: Verbosity,
@@ -24,30 +41,19 @@ pub fn analysis_stats(
     only: Option<&str>,
     with_deps: bool,
     randomize: bool,
+    parallel: bool,
     load_output_dirs: bool,
     with_proc_macro: bool,
 ) -> Result<()> {
     let db_load_time = Instant::now();
-    let (mut host, roots) = load_cargo(path, load_output_dirs, with_proc_macro)?;
+    let (host, vfs) = load_cargo(path, load_output_dirs, with_proc_macro)?;
     let db = host.raw_database();
-    println!("Database loaded, {} roots, {:?}", roots.len(), db_load_time.elapsed());
+    println!("Database loaded {:?}", db_load_time.elapsed());
     let analysis_time = Instant::now();
     let mut num_crates = 0;
-    let mut visited_modules = HashSet::new();
+    let mut visited_modules = FxHashSet::default();
     let mut visit_queue = Vec::new();
 
-    let members =
-        roots
-            .into_iter()
-            .filter_map(|(source_root_id, project_root)| {
-                if with_deps || project_root.is_member() {
-                    Some(source_root_id)
-                } else {
-                    None
-                }
-            })
-            .collect::<HashSet<_>>();
-
     let mut krates = Crate::all(db);
     if randomize {
         krates.shuffle(&mut thread_rng());
@@ -55,7 +61,10 @@ pub fn analysis_stats(
     for krate in krates {
         let module = krate.root_module(db).expect("crate without root module");
         let file_id = module.definition_source(db).file_id;
-        if members.contains(&db.file_source_root(file_id.original_file(db))) {
+        let file_id = file_id.original_file(db);
+        let source_root = db.file_source_root(file_id);
+        let source_root = db.source_root(source_root);
+        if !source_root.is_library || with_deps {
             num_crates += 1;
             visit_queue.push(module);
         }
@@ -98,12 +107,26 @@ pub fn analysis_stats(
         funcs.shuffle(&mut thread_rng());
     }
 
-    let inference_time = Instant::now();
     let mut bar = match verbosity {
         Verbosity::Quiet | Verbosity::Spammy => ProgressReport::hidden(),
         _ => ProgressReport::new(funcs.len() as u64),
     };
 
+    if parallel {
+        let inference_time = Instant::now();
+        let snap = Snap(db.snapshot());
+        funcs
+            .par_iter()
+            .map_with(snap, |snap, &f| {
+                let f_id = FunctionId::from(f);
+                snap.0.body(f_id.into());
+                snap.0.infer(f_id.into());
+            })
+            .count();
+        println!("Parallel Inference: {:?}, {}", inference_time.elapsed(), ra_prof::memory_usage());
+    }
+
+    let inference_time = Instant::now();
     bar.tick();
     let mut num_exprs = 0;
     let mut num_exprs_unknown = 0;
@@ -128,9 +151,9 @@ pub fn analysis_stats(
         if verbosity.is_verbose() {
             let src = f.source(db);
             let original_file = src.file_id.original_file(db);
-            let path = db.file_relative_path(original_file);
+            let path = vfs.file_path(original_file);
             let syntax_range = src.value.syntax().text_range();
-            format_to!(msg, " ({:?} {:?})", path, syntax_range);
+            format_to!(msg, " ({} {:?})", path, syntax_range);
         }
         if verbosity.is_spammy() {
             bar.println(msg.to_string());
@@ -196,7 +219,7 @@ pub fn analysis_stats(
                         let root = db.parse_or_expand(src.file_id).unwrap();
                         let node = src.map(|e| e.to_node(&root).syntax().clone());
                         let original_range = original_range(db, node.as_ref());
-                        let path = db.file_relative_path(original_range.file_id);
+                        let path = vfs.file_path(original_range.file_id);
                         let line_index =
                             host.analysis().file_line_index(original_range.file_id).unwrap();
                         let text_range = original_range.range;
@@ -253,12 +276,7 @@ pub fn analysis_stats(
     println!("Total: {:?}, {}", analysis_time.elapsed(), ra_prof::memory_usage());
 
     if memory_usage {
-        for (name, bytes) in host.per_query_memory_usage() {
-            println!("{:>8} {}", bytes, name)
-        }
-        let before = ra_prof::memory_usage();
-        drop(host);
-        println!("leftover: {}", before.allocated - ra_prof::memory_usage().allocated)
+        print_memory_usage(host, vfs);
     }
 
     Ok(())
diff --git a/crates/rust-analyzer/src/cli/diagnostics.rs b/crates/rust-analyzer/src/cli/diagnostics.rs
index 60daefa3e..6f3c1c1f9 100644
--- a/crates/rust-analyzer/src/cli/diagnostics.rs
+++ b/crates/rust-analyzer/src/cli/diagnostics.rs
@@ -1,69 +1,61 @@
 //! Analyze all modules in a project for diagnostics. Exits with a non-zero status
 //! code if any errors are found.
 
+use std::path::Path;
+
 use anyhow::anyhow;
+use rustc_hash::FxHashSet;
+
+use hir::Crate;
 use ra_db::SourceDatabaseExt;
 use ra_ide::Severity;
-use std::{collections::HashSet, path::Path};
 
 use crate::cli::{load_cargo::load_cargo, Result};
-use hir::Semantics;
 
 pub fn diagnostics(
     path: &Path,
     load_output_dirs: bool,
     with_proc_macro: bool,
-    all: bool,
+    _all: bool,
 ) -> Result<()> {
-    let (host, roots) = load_cargo(path, load_output_dirs, with_proc_macro)?;
+    let (host, _vfs) = load_cargo(path, load_output_dirs, with_proc_macro)?;
     let db = host.raw_database();
     let analysis = host.analysis();
-    let semantics = Semantics::new(db);
-    let members = roots
-        .into_iter()
-        .filter_map(|(source_root_id, project_root)| {
-            // filter out dependencies
-            if project_root.is_member() {
-                Some(source_root_id)
-            } else {
-                None
-            }
-        })
-        .collect::<HashSet<_>>();
 
     let mut found_error = false;
-    let mut visited_files = HashSet::new();
-    for source_root_id in members {
-        for file_id in db.source_root(source_root_id).walk() {
-            // Filter out files which are not actually modules (unless `--all` flag is
-            // passed). In the rust-analyzer repository this filters out the parser test files.
-            if semantics.to_module_def(file_id).is_some() || all {
-                if !visited_files.contains(&file_id) {
-                    let crate_name = if let Some(module) = semantics.to_module_def(file_id) {
-                        if let Some(name) = module.krate().display_name(db) {
-                            format!("{}", name)
-                        } else {
-                            String::from("unknown")
-                        }
-                    } else {
-                        String::from("unknown")
-                    };
-                    println!(
-                        "processing crate: {}, module: {}",
-                        crate_name,
-                        db.file_relative_path(file_id)
-                    );
-                    for diagnostic in analysis.diagnostics(file_id).unwrap() {
-                        if matches!(diagnostic.severity, Severity::Error) {
-                            found_error = true;
-                        }
+    let mut visited_files = FxHashSet::default();
 
-                        println!("{:?}", diagnostic);
-                    }
+    let mut work = Vec::new();
+    let krates = Crate::all(db);
+    for krate in krates {
+        let module = krate.root_module(db).expect("crate without root module");
+        let file_id = module.definition_source(db).file_id;
+        let file_id = file_id.original_file(db);
+        let source_root = db.file_source_root(file_id);
+        let source_root = db.source_root(source_root);
+        if !source_root.is_library {
+            work.push(module);
+        }
+    }
 
-                    visited_files.insert(file_id);
+    for module in work {
+        let file_id = module.definition_source(db).file_id.original_file(db);
+        if !visited_files.contains(&file_id) {
+            let crate_name = if let Some(name) = module.krate().display_name(db) {
+                format!("{}", name)
+            } else {
+                String::from("unknown")
+            };
+            println!("processing crate: {}, module: {}", crate_name, _vfs.file_path(file_id));
+            for diagnostic in analysis.diagnostics(file_id).unwrap() {
+                if matches!(diagnostic.severity, Severity::Error) {
+                    found_error = true;
                 }
+
+                println!("{:?}", diagnostic);
             }
+
+            visited_files.insert(file_id);
         }
     }
 
diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index 8eaf75ff6..a43bf2244 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -1,173 +1,96 @@
 //! Loads a Cargo project into a static instance of analysis, without support
 //! for incorporating changes.
-
-use std::path::{Path, PathBuf};
+use std::{path::Path, sync::Arc};
 
 use anyhow::Result;
 use crossbeam_channel::{unbounded, Receiver};
-use ra_db::{ExternSourceId, FileId, SourceRootId};
+use ra_db::CrateGraph;
 use ra_ide::{AnalysisChange, AnalysisHost};
-use ra_project_model::{
-    get_rustc_cfg_options, CargoConfig, PackageRoot, ProcMacroClient, ProjectRoot, ProjectWorkspace,
-};
-use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
-use rustc_hash::{FxHashMap, FxHashSet};
-
-use crate::vfs_glob::RustPackageFilterBuilder;
+use ra_project_model::{CargoConfig, ProcMacroClient, ProjectManifest, ProjectWorkspace};
+use vfs::{loader::Handle, AbsPath, AbsPathBuf};
 
-fn vfs_file_to_id(f: ra_vfs::VfsFile) -> FileId {
-    FileId(f.0)
-}
-fn vfs_root_to_id(r: ra_vfs::VfsRoot) -> SourceRootId {
-    SourceRootId(r.0)
-}
+use crate::reload::{ProjectFolders, SourceRootConfig};
 
 pub fn load_cargo(
     root: &Path,
     load_out_dirs_from_check: bool,
     with_proc_macro: bool,
-) -> Result<(AnalysisHost, FxHashMap<SourceRootId, PackageRoot>)> {
-    let root = std::env::current_dir()?.join(root);
-    let root = ProjectRoot::discover_single(&root)?;
+) -> Result<(AnalysisHost, vfs::Vfs)> {
+    let root = AbsPathBuf::assert(std::env::current_dir()?.join(root));
+    let root = ProjectManifest::discover_single(&root)?;
     let ws = ProjectWorkspace::load(
         root,
         &CargoConfig { load_out_dirs_from_check, ..Default::default() },
         true,
     )?;
 
-    let mut extern_dirs = FxHashSet::default();
-    extern_dirs.extend(ws.out_dirs());
-
-    let mut project_roots = ws.to_roots();
-    project_roots.extend(extern_dirs.iter().cloned().map(PackageRoot::new_non_member));
-
     let (sender, receiver) = unbounded();
-    let sender = Box::new(move |t| sender.send(t).unwrap());
-    let (mut vfs, roots) = Vfs::new(
-        project_roots
-            .iter()
-            .map(|pkg_root| {
-                RootEntry::new(
-                    pkg_root.path().to_owned(),
-                    RustPackageFilterBuilder::default()
-                        .set_member(pkg_root.is_member())
-                        .into_vfs_filter(),
-                )
-            })
-            .collect(),
-        sender,
-        Watch(false),
-    );
-
-    let source_roots = roots
-        .into_iter()
-        .map(|vfs_root| {
-            let source_root_id = vfs_root_to_id(vfs_root);
-            let project_root = project_roots
-                .iter()
-                .find(|it| it.path() == vfs.root2path(vfs_root))
-                .unwrap()
-                .clone();
-            (source_root_id, project_root)
-        })
-        .collect::<FxHashMap<_, _>>();
+    let mut vfs = vfs::Vfs::default();
+    let mut loader = {
+        let loader =
+            vfs_notify::NotifyHandle::spawn(Box::new(move |msg| sender.send(msg).unwrap()));
+        Box::new(loader)
+    };
 
-    let proc_macro_client = if !with_proc_macro {
-        ProcMacroClient::dummy()
-    } else {
+    let proc_macro_client = if with_proc_macro {
         let path = std::env::current_exe()?;
         ProcMacroClient::extern_process(path, &["proc-macro"]).unwrap()
+    } else {
+        ProcMacroClient::dummy()
     };
-    let host = load(&source_roots, ws, &mut vfs, receiver, extern_dirs, &proc_macro_client);
-    Ok((host, source_roots))
+
+    let crate_graph = ws.to_crate_graph(None, &proc_macro_client, &mut |path: &AbsPath| {
+        let contents = loader.load_sync(path);
+        let path = vfs::VfsPath::from(path.to_path_buf());
+        vfs.set_file_contents(path.clone(), contents);
+        vfs.file_id(&path)
+    });
+
+    let project_folders = ProjectFolders::new(&[ws]);
+    loader.set_config(vfs::loader::Config { load: project_folders.load, watch: vec![] });
+
+    log::debug!("crate graph: {:?}", crate_graph);
+    let host = load(crate_graph, project_folders.source_root_config, &mut vfs, &receiver);
+    Ok((host, vfs))
 }
 
-pub(crate) fn load(
-    source_roots: &FxHashMap<SourceRootId, PackageRoot>,
-    ws: ProjectWorkspace,
-    vfs: &mut Vfs,
-    receiver: Receiver<VfsTask>,
-    extern_dirs: FxHashSet<PathBuf>,
-    proc_macro_client: &ProcMacroClient,
+fn load(
+    crate_graph: CrateGraph,
+    source_root_config: SourceRootConfig,
+    vfs: &mut vfs::Vfs,
+    receiver: &Receiver<vfs::loader::Message>,
 ) -> AnalysisHost {
     let lru_cap = std::env::var("RA_LRU_CAP").ok().and_then(|it| it.parse::<usize>().ok());
     let mut host = AnalysisHost::new(lru_cap);
     let mut analysis_change = AnalysisChange::new();
 
     // wait until Vfs has loaded all roots
-    let mut roots_loaded = FxHashSet::default();
-    let mut extern_source_roots = FxHashMap::default();
     for task in receiver {
-        vfs.handle_task(task);
-        let mut done = false;
-        for change in vfs.commit_changes() {
-            match change {
-                VfsChange::AddRoot { root, files } => {
-                    let source_root_id = vfs_root_to_id(root);
-                    let is_local = source_roots[&source_root_id].is_member();
-                    log::debug!(
-                        "loaded source root {:?} with path {:?}",
-                        source_root_id,
-                        vfs.root2path(root)
-                    );
-                    analysis_change.add_root(source_root_id, is_local);
-                    analysis_change.set_debug_root_path(
-                        source_root_id,
-                        source_roots[&source_root_id].path().display().to_string(),
-                    );
-
-                    let vfs_root_path = vfs.root2path(root);
-                    if extern_dirs.contains(&vfs_root_path) {
-                        extern_source_roots.insert(vfs_root_path, ExternSourceId(root.0));
-                    }
-
-                    let mut file_map = FxHashMap::default();
-                    for (vfs_file, path, text) in files {
-                        let file_id = vfs_file_to_id(vfs_file);
-                        analysis_change.add_file(source_root_id, file_id, path.clone(), text);
-                        file_map.insert(path, file_id);
-                    }
-                    roots_loaded.insert(source_root_id);
-                    if roots_loaded.len() == vfs.n_roots() {
-                        done = true;
-                    }
-                }
-                VfsChange::AddFile { root, file, path, text } => {
-                    let source_root_id = vfs_root_to_id(root);
-                    let file_id = vfs_file_to_id(file);
-                    analysis_change.add_file(source_root_id, file_id, path, text);
+        match task {
+            vfs::loader::Message::Progress { n_done, n_total } => {
+                if n_done == n_total {
+                    break;
                 }
-                VfsChange::RemoveFile { .. } | VfsChange::ChangeFile { .. } => {
-                    // We just need the first scan, so just ignore these
+            }
+            vfs::loader::Message::Loaded { files } => {
+                for (path, contents) in files {
+                    vfs.set_file_contents(path.into(), contents)
                 }
             }
         }
-        if done {
-            break;
+    }
+    let changes = vfs.take_changes();
+    for file in changes {
+        if file.exists() {
+            let contents = vfs.file_contents(file.file_id).to_vec();
+            if let Ok(text) = String::from_utf8(contents) {
+                analysis_change.change_file(file.file_id, Some(Arc::new(text)))
+            }
         }
     }
+    let source_roots = source_root_config.partition(&vfs);
+    analysis_change.set_roots(source_roots);
 
-    // FIXME: cfg options?
-    let default_cfg_options = {
-        let mut opts = get_rustc_cfg_options(None);
-        opts.insert_atom("test".into());
-        opts.insert_atom("debug_assertion".into());
-        opts
-    };
-
-    let crate_graph = ws.to_crate_graph(
-        &default_cfg_options,
-        &extern_source_roots,
-        proc_macro_client,
-        &mut |path: &Path| {
-            // Some path from metadata will be non canonicalized, e.g. /foo/../bar/lib.rs
-            let path = path.canonicalize().ok()?;
-            let vfs_file = vfs.load(&path);
-            log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
-            vfs_file.map(vfs_file_to_id)
-        },
-    );
-    log::debug!("crate graph: {:?}", crate_graph);
     analysis_change.set_crate_graph(crate_graph);
 
     host.apply_change(analysis_change);
@@ -183,7 +106,7 @@ mod tests {
     #[test]
     fn test_loading_rust_analyzer() {
         let path = Path::new(env!("CARGO_MANIFEST_DIR")).parent().unwrap().parent().unwrap();
-        let (host, _roots) = load_cargo(path, false, false).unwrap();
+        let (host, _vfs) = load_cargo(path, false, false).unwrap();
         let n_crates = Crate::all(host.raw_database()).len();
         // RA has quite a few crates, but the exact count doesn't matter
         assert!(n_crates > 20);
diff --git a/crates/rust-analyzer/src/cli/ssr.rs b/crates/rust-analyzer/src/cli/ssr.rs
new file mode 100644
index 000000000..4fb829ea5
--- /dev/null
+++ b/crates/rust-analyzer/src/cli/ssr.rs
@@ -0,0 +1,71 @@
+//! Applies structured search replace rules from the command line.
+
+use crate::cli::{load_cargo::load_cargo, Result};
+use ra_ide::SourceFileEdit;
+use ra_ssr::{MatchFinder, SsrPattern, SsrRule};
+
+pub fn apply_ssr_rules(rules: Vec<SsrRule>) -> Result<()> {
+    use ra_db::SourceDatabaseExt;
+    use ra_ide_db::symbol_index::SymbolsDatabase;
+    let (host, vfs) = load_cargo(&std::env::current_dir()?, true, true)?;
+    let db = host.raw_database();
+    let mut match_finder = MatchFinder::new(db);
+    for rule in rules {
+        match_finder.add_rule(rule);
+    }
+    let mut edits = Vec::new();
+    for &root in db.local_roots().iter() {
+        let sr = db.source_root(root);
+        for file_id in sr.iter() {
+            if let Some(edit) = match_finder.edits_for_file(file_id) {
+                edits.push(SourceFileEdit { file_id, edit });
+            }
+        }
+    }
+    for edit in edits {
+        if let Some(path) = vfs.file_path(edit.file_id).as_path() {
+            let mut contents = db.file_text(edit.file_id).to_string();
+            edit.edit.apply(&mut contents);
+            std::fs::write(path, contents)?;
+        }
+    }
+    Ok(())
+}
+
+/// Searches for `patterns`, printing debug information for any nodes whose text exactly matches
+/// `debug_snippet`. This is intended for debugging and probably isn't in it's current form useful
+/// for much else.
+pub fn search_for_patterns(patterns: Vec<SsrPattern>, debug_snippet: Option<String>) -> Result<()> {
+    use ra_db::SourceDatabaseExt;
+    use ra_ide_db::symbol_index::SymbolsDatabase;
+    let (host, vfs) = load_cargo(&std::env::current_dir()?, true, true)?;
+    let db = host.raw_database();
+    let mut match_finder = MatchFinder::new(db);
+    for pattern in patterns {
+        match_finder.add_search_pattern(pattern);
+    }
+    for &root in db.local_roots().iter() {
+        let sr = db.source_root(root);
+        for file_id in sr.iter() {
+            if let Some(debug_snippet) = &debug_snippet {
+                for debug_info in match_finder.debug_where_text_equal(file_id, debug_snippet) {
+                    println!("{:#?}", debug_info);
+                }
+            } else {
+                let matches = match_finder.find_matches_in_file(file_id);
+                if !matches.matches.is_empty() {
+                    let matches = matches.flattened().matches;
+                    if let Some(path) = vfs.file_path(file_id).as_path() {
+                        println!("{} matches in '{}'", matches.len(), path.to_string_lossy());
+                    }
+                    // We could possibly at some point do something more useful than just printing
+                    // the matched text. For now though, that's the easiest thing to do.
+                    for m in matches {
+                        println!("{}", m.matched_text());
+                    }
+                }
+            }
+        }
+    }
+    Ok(())
+}
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index c0f7c2c0c..ed5e52871 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -9,52 +9,79 @@
 
 use std::{ffi::OsString, path::PathBuf};
 
+use flycheck::FlycheckConfig;
 use lsp_types::ClientCapabilities;
-use ra_flycheck::FlycheckConfig;
-use ra_ide::{AssistConfig, CompletionConfig, InlayHintsConfig};
-use ra_project_model::CargoConfig;
+use ra_ide::{AssistConfig, CompletionConfig, HoverConfig, InlayHintsConfig};
+use ra_project_model::{CargoConfig, ProjectJson, ProjectJsonData, ProjectManifest};
 use serde::Deserialize;
+use vfs::AbsPathBuf;
+
+use crate::diagnostics::DiagnosticsConfig;
 
 #[derive(Debug, Clone)]
 pub struct Config {
     pub client_caps: ClientCapsConfig,
 
-    pub with_sysroot: bool,
     pub publish_diagnostics: bool,
+    pub diagnostics: DiagnosticsConfig,
     pub lru_capacity: Option<usize>,
     pub proc_macro_srv: Option<(PathBuf, Vec<OsString>)>,
     pub files: FilesConfig,
     pub notifications: NotificationsConfig,
 
+    pub cargo_autoreload: bool,
     pub cargo: CargoConfig,
     pub rustfmt: RustfmtConfig,
-    pub check: Option<FlycheckConfig>,
+    pub flycheck: Option<FlycheckConfig>,
 
     pub inlay_hints: InlayHintsConfig,
     pub completion: CompletionConfig,
     pub assist: AssistConfig,
     pub call_info_full: bool,
     pub lens: LensConfig,
+    pub hover: HoverConfig,
+
+    pub with_sysroot: bool,
+    pub linked_projects: Vec<LinkedProject>,
+    pub root_path: AbsPathBuf,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum LinkedProject {
+    ProjectManifest(ProjectManifest),
+    InlineJsonProject(ProjectJson),
+}
+
+impl From<ProjectManifest> for LinkedProject {
+    fn from(v: ProjectManifest) -> Self {
+        LinkedProject::ProjectManifest(v)
+    }
+}
+
+impl From<ProjectJson> for LinkedProject {
+    fn from(v: ProjectJson) -> Self {
+        LinkedProject::InlineJsonProject(v)
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct LensConfig {
     pub run: bool,
     pub debug: bool,
-    pub impementations: bool,
+    pub implementations: bool,
 }
 
 impl Default for LensConfig {
     fn default() -> Self {
-        Self { run: true, debug: true, impementations: true }
+        Self { run: true, debug: true, implementations: true }
     }
 }
 
 impl LensConfig {
-    pub const NO_LENS: LensConfig = Self { run: false, debug: false, impementations: false };
+    pub const NO_LENS: LensConfig = Self { run: false, debug: false, implementations: false };
 
     pub fn any(&self) -> bool {
-        self.impementations || self.runnable()
+        self.implementations || self.runnable()
     }
 
     pub fn none(&self) -> bool {
@@ -85,14 +112,8 @@ pub struct NotificationsConfig {
 
 #[derive(Debug, Clone)]
 pub enum RustfmtConfig {
-    Rustfmt {
-        extra_args: Vec<String>,
-    },
-    #[allow(unused)]
-    CustomCommand {
-        command: String,
-        args: Vec<String>,
-    },
+    Rustfmt { extra_args: Vec<String> },
+    CustomCommand { command: String, args: Vec<String> },
 }
 
 #[derive(Debug, Clone, Default)]
@@ -103,27 +124,33 @@ pub struct ClientCapsConfig {
     pub code_action_literals: bool,
     pub work_done_progress: bool,
     pub code_action_group: bool,
+    pub resolve_code_action: bool,
+    pub hover_actions: bool,
+    pub status_notification: bool,
 }
 
-impl Default for Config {
-    fn default() -> Self {
+impl Config {
+    pub fn new(root_path: AbsPathBuf) -> Self {
         Config {
             client_caps: ClientCapsConfig::default(),
 
             with_sysroot: true,
             publish_diagnostics: true,
+            diagnostics: DiagnosticsConfig::default(),
             lru_capacity: None,
             proc_macro_srv: None,
             files: FilesConfig { watcher: FilesWatcher::Notify, exclude: Vec::new() },
             notifications: NotificationsConfig { cargo_toml_not_found: true },
 
+            cargo_autoreload: true,
             cargo: CargoConfig::default(),
             rustfmt: RustfmtConfig::Rustfmt { extra_args: Vec::new() },
-            check: Some(FlycheckConfig::CargoCommand {
+            flycheck: Some(FlycheckConfig::CargoCommand {
                 command: "check".to_string(),
                 all_targets: true,
-                all_features: true,
+                all_features: false,
                 extra_args: Vec::new(),
+                features: Vec::new(),
             }),
 
             inlay_hints: InlayHintsConfig {
@@ -141,116 +168,117 @@ impl Default for Config {
             assist: AssistConfig::default(),
             call_info_full: true,
             lens: LensConfig::default(),
+            hover: HoverConfig::default(),
+            linked_projects: Vec::new(),
+            root_path,
         }
     }
-}
 
-impl Config {
-    #[rustfmt::skip]
-    pub fn update(&mut self, value: &serde_json::Value) {
-        log::info!("Config::update({:#})", value);
-
-        let client_caps = self.client_caps.clone();
-        *self = Default::default();
-        self.client_caps = client_caps;
-
-        set(value, "/withSysroot", &mut self.with_sysroot);
-        set(value, "/diagnostics/enable", &mut self.publish_diagnostics);
-        set(value, "/lruCapacity", &mut self.lru_capacity);
-        self.files.watcher = match get(value, "/files/watcher") {
-            Some("client") => FilesWatcher::Client,
-            Some("notify") | _ => FilesWatcher::Notify
+    pub fn update(&mut self, json: serde_json::Value) {
+        log::info!("Config::update({:#})", json);
+        let data = ConfigData::from_json(json);
+
+        self.with_sysroot = data.withSysroot;
+        self.publish_diagnostics = data.diagnostics_enable;
+        self.diagnostics = DiagnosticsConfig {
+            warnings_as_info: data.diagnostics_warningsAsInfo,
+            warnings_as_hint: data.diagnostics_warningsAsHint,
+        };
+        self.lru_capacity = data.lruCapacity;
+        self.files.watcher = match data.files_watcher.as_str() {
+            "notify" => FilesWatcher::Notify,
+            "client" | _ => FilesWatcher::Client,
+        };
+        self.notifications =
+            NotificationsConfig { cargo_toml_not_found: data.notifications_cargoTomlNotFound };
+        self.cargo_autoreload = data.cargo_autoreload;
+        self.cargo = CargoConfig {
+            no_default_features: data.cargo_noDefaultFeatures,
+            all_features: data.cargo_allFeatures,
+            features: data.cargo_features.clone(),
+            load_out_dirs_from_check: data.cargo_loadOutDirsFromCheck,
+            target: data.cargo_target,
         };
-        set(value, "/notifications/cargoTomlNotFound", &mut self.notifications.cargo_toml_not_found);
-
-        set(value, "/cargo/noDefaultFeatures", &mut self.cargo.no_default_features);
-        set(value, "/cargo/allFeatures", &mut self.cargo.all_features);
-        set(value, "/cargo/features", &mut self.cargo.features);
-        set(value, "/cargo/loadOutDirsFromCheck", &mut self.cargo.load_out_dirs_from_check);
-        set(value, "/cargo/target", &mut self.cargo.target);
-
-        match get(value, "/procMacro/enable") {
-            Some(true) => {
-                if let Ok(path) = std::env::current_exe() {
-                    self.proc_macro_srv = Some((path, vec!["proc-macro".into()]));
-                }
-            }
-            _ => self.proc_macro_srv = None,
-        }
 
-        match get::<Vec<String>>(value, "/rustfmt/overrideCommand") {
+        self.proc_macro_srv = if data.procMacro_enable {
+            std::env::current_exe().ok().map(|path| (path, vec!["proc-macro".into()]))
+        } else {
+            None
+        };
+
+        self.rustfmt = match data.rustfmt_overrideCommand {
             Some(mut args) if !args.is_empty() => {
                 let command = args.remove(0);
-                self.rustfmt = RustfmtConfig::CustomCommand {
-                    command,
-                    args,
-                }
-            }
-            _ => {
-                if let RustfmtConfig::Rustfmt { extra_args } = &mut self.rustfmt {
-                    set(value, "/rustfmt/extraArgs", extra_args);
-                }
+                RustfmtConfig::CustomCommand { command, args }
             }
+            Some(_) | None => RustfmtConfig::Rustfmt { extra_args: data.rustfmt_extraArgs },
         };
 
-        if let Some(false) = get(value, "/checkOnSave/enable") {
-            // check is disabled
-            self.check = None;
-        } else {
-            // check is enabled
-            match get::<Vec<String>>(value, "/checkOnSave/overrideCommand") {
-                // first see if the user has completely overridden the command
+        self.flycheck = if data.checkOnSave_enable {
+            let flycheck_config = match data.checkOnSave_overrideCommand {
                 Some(mut args) if !args.is_empty() => {
                     let command = args.remove(0);
-                    self.check = Some(FlycheckConfig::CustomCommand {
-                        command,
-                        args,
-                    });
-                }
-                // otherwise configure command customizations
-                _ => {
-                    if let Some(FlycheckConfig::CargoCommand { command, extra_args, all_targets, all_features })
-                        = &mut self.check
-                    {
-                        set(value, "/checkOnSave/extraArgs", extra_args);
-                        set(value, "/checkOnSave/command", command);
-                        set(value, "/checkOnSave/allTargets", all_targets);
-                        set(value, "/checkOnSave/allFeatures", all_features);
-                    }
+                    FlycheckConfig::CustomCommand { command, args }
                 }
+                Some(_) | None => FlycheckConfig::CargoCommand {
+                    command: data.checkOnSave_command,
+                    all_targets: data.checkOnSave_allTargets,
+                    all_features: data.checkOnSave_allFeatures.unwrap_or(data.cargo_allFeatures),
+                    features: data.checkOnSave_features.unwrap_or(data.cargo_features),
+                    extra_args: data.checkOnSave_extraArgs,
+                },
             };
-        }
-
-        set(value, "/inlayHints/typeHints", &mut self.inlay_hints.type_hints);
-        set(value, "/inlayHints/parameterHints", &mut self.inlay_hints.parameter_hints);
-        set(value, "/inlayHints/chainingHints", &mut self.inlay_hints.chaining_hints);
-        set(value, "/inlayHints/maxLength", &mut self.inlay_hints.max_length);
-        set(value, "/completion/postfix/enable", &mut self.completion.enable_postfix_completions);
-        set(value, "/completion/addCallParenthesis", &mut self.completion.add_call_parenthesis);
-        set(value, "/completion/addCallArgumentSnippets", &mut self.completion.add_call_argument_snippets);
-        set(value, "/callInfo/full", &mut self.call_info_full);
-
-        let mut lens_enabled = true;
-        set(value, "/lens/enable", &mut lens_enabled);
-        if lens_enabled {
-            set(value, "/lens/run", &mut self.lens.run);
-            set(value, "/lens/debug", &mut self.lens.debug);
-            set(value, "/lens/implementations", &mut self.lens.impementations);
+            Some(flycheck_config)
         } else {
-            self.lens = LensConfig::NO_LENS;
-        }
+            None
+        };
 
-        log::info!("Config::update() = {:#?}", self);
+        self.inlay_hints = InlayHintsConfig {
+            type_hints: data.inlayHints_typeHints,
+            parameter_hints: data.inlayHints_parameterHints,
+            chaining_hints: data.inlayHints_chainingHints,
+            max_length: data.inlayHints_maxLength,
+        };
 
-        fn get<'a, T: Deserialize<'a>>(value: &'a serde_json::Value, pointer: &str) -> Option<T> {
-            value.pointer(pointer).and_then(|it| T::deserialize(it).ok())
-        }
+        self.completion.enable_postfix_completions = data.completion_postfix_enable;
+        self.completion.add_call_parenthesis = data.completion_addCallParenthesis;
+        self.completion.add_call_argument_snippets = data.completion_addCallArgumentSnippets;
+
+        self.call_info_full = data.callInfo_full;
+
+        self.lens = LensConfig {
+            run: data.lens_enable && data.lens_run,
+            debug: data.lens_enable && data.lens_debug,
+            implementations: data.lens_enable && data.lens_implementations,
+        };
 
-        fn set<'a, T: Deserialize<'a>>(value: &'a serde_json::Value, pointer: &str, slot: &mut T) {
-            if let Some(new_value) = get(value, pointer) {
-                *slot = new_value
+        if !data.linkedProjects.is_empty() {
+            self.linked_projects.clear();
+            for linked_project in data.linkedProjects {
+                let linked_project = match linked_project {
+                    ManifestOrProjectJson::Manifest(it) => {
+                        let path = self.root_path.join(it);
+                        match ProjectManifest::from_manifest_file(path) {
+                            Ok(it) => it.into(),
+                            Err(_) => continue,
+                        }
+                    }
+                    ManifestOrProjectJson::ProjectJson(it) => {
+                        ProjectJson::new(&self.root_path, it).into()
+                    }
+                };
+                self.linked_projects.push(linked_project);
             }
         }
+
+        self.hover = HoverConfig {
+            implementations: data.hoverActions_enable && data.hoverActions_implementations,
+            run: data.hoverActions_enable && data.hoverActions_run,
+            debug: data.hoverActions_enable && data.hoverActions_debug,
+            goto_type_def: data.hoverActions_enable && data.hoverActions_gotoTypeDef,
+        };
+
+        log::info!("Config::update() = {:#?}", self);
     }
 
     pub fn update_caps(&mut self, caps: &ClientCapabilities) {
@@ -293,13 +321,101 @@ impl Config {
 
         self.assist.allow_snippets(false);
         if let Some(experimental) = &caps.experimental {
-            let snippet_text_edit =
-                experimental.get("snippetTextEdit").and_then(|it| it.as_bool()) == Some(true);
+            let get_bool =
+                |index: &str| experimental.get(index).and_then(|it| it.as_bool()) == Some(true);
+
+            let snippet_text_edit = get_bool("snippetTextEdit");
             self.assist.allow_snippets(snippet_text_edit);
 
-            let code_action_group =
-                experimental.get("codeActionGroup").and_then(|it| it.as_bool()) == Some(true);
-            self.client_caps.code_action_group = code_action_group
+            self.client_caps.code_action_group = get_bool("codeActionGroup");
+            self.client_caps.resolve_code_action = get_bool("resolveCodeAction");
+            self.client_caps.hover_actions = get_bool("hoverActions");
+            self.client_caps.status_notification = get_bool("statusNotification");
+        }
+    }
+}
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+enum ManifestOrProjectJson {
+    Manifest(PathBuf),
+    ProjectJson(ProjectJsonData),
+}
+
+macro_rules! config_data {
+    (struct $name:ident { $($field:ident: $ty:ty = $default:expr,)*}) => {
+        #[allow(non_snake_case)]
+        struct $name { $($field: $ty,)* }
+        impl $name {
+            fn from_json(mut json: serde_json::Value) -> $name {
+                $name {$(
+                    $field: {
+                        let pointer = stringify!($field).replace('_', "/");
+                        let pointer = format!("/{}", pointer);
+                        json.pointer_mut(&pointer)
+                            .and_then(|it| serde_json::from_value(it.take()).ok())
+                            .unwrap_or($default)
+                    },
+                )*}
+            }
         }
+
+    };
+}
+
+config_data! {
+    struct ConfigData {
+        callInfo_full: bool = true,
+
+        cargo_autoreload: bool           = true,
+        cargo_allFeatures: bool          = false,
+        cargo_features: Vec<String>      = Vec::new(),
+        cargo_loadOutDirsFromCheck: bool = false,
+        cargo_noDefaultFeatures: bool    = false,
+        cargo_target: Option<String>     = None,
+
+        checkOnSave_allFeatures: Option<bool>            = None,
+        checkOnSave_allTargets: bool                     = true,
+        checkOnSave_command: String                      = "check".into(),
+        checkOnSave_enable: bool                         = false,
+        checkOnSave_extraArgs: Vec<String>               = Vec::new(),
+        checkOnSave_features: Option<Vec<String>>        = None,
+        checkOnSave_overrideCommand: Option<Vec<String>> = None,
+
+        completion_addCallArgumentSnippets: bool = true,
+        completion_addCallParenthesis: bool      = true,
+        completion_postfix_enable: bool          = true,
+
+        diagnostics_enable: bool                = true,
+        diagnostics_warningsAsHint: Vec<String> = Vec::new(),
+        diagnostics_warningsAsInfo: Vec<String> = Vec::new(),
+
+        files_watcher: String = "client".into(),
+
+        hoverActions_debug: bool           = true,
+        hoverActions_enable: bool          = true,
+        hoverActions_gotoTypeDef: bool     = true,
+        hoverActions_implementations: bool = true,
+        hoverActions_run: bool             = true,
+
+        inlayHints_chainingHints: bool      = true,
+        inlayHints_maxLength: Option<usize> = None,
+        inlayHints_parameterHints: bool     = true,
+        inlayHints_typeHints: bool          = true,
+
+        lens_debug: bool           = true,
+        lens_enable: bool          = true,
+        lens_implementations: bool = true,
+        lens_run: bool             = true,
+
+        linkedProjects: Vec<ManifestOrProjectJson> = Vec::new(),
+        lruCapacity: Option<usize>                 = None,
+        notifications_cargoTomlNotFound: bool      = true,
+        procMacro_enable: bool                     = false,
+
+        rustfmt_extraArgs: Vec<String>               = Vec::new(),
+        rustfmt_overrideCommand: Option<Vec<String>> = None,
+
+        withSysroot: bool = true,
     }
 }
diff --git a/crates/rust-analyzer/src/diagnostics.rs b/crates/rust-analyzer/src/diagnostics.rs
index 25856c543..d24c55cee 100644
--- a/crates/rust-analyzer/src/diagnostics.rs
+++ b/crates/rust-analyzer/src/diagnostics.rs
@@ -1,45 +1,47 @@
 //! Book keeping for keeping diagnostics easily in sync with the client.
 pub(crate) mod to_proto;
 
-use std::{collections::HashMap, sync::Arc};
+use std::{mem, sync::Arc};
 
-use lsp_types::{Diagnostic, Range};
 use ra_ide::FileId;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::lsp_ext;
 
-pub type CheckFixes = Arc<HashMap<FileId, Vec<Fix>>>;
+pub(crate) type CheckFixes = Arc<FxHashMap<FileId, Vec<Fix>>>;
 
 #[derive(Debug, Default, Clone)]
-pub struct DiagnosticCollection {
-    pub native: HashMap<FileId, Vec<Diagnostic>>,
-    pub check: HashMap<FileId, Vec<Diagnostic>>,
-    pub check_fixes: CheckFixes,
+pub struct DiagnosticsConfig {
+    pub warnings_as_info: Vec<String>,
+    pub warnings_as_hint: Vec<String>,
 }
 
-#[derive(Debug, Clone)]
-pub struct Fix {
-    pub range: Range,
-    pub action: lsp_ext::CodeAction,
+#[derive(Debug, Default, Clone)]
+pub(crate) struct DiagnosticCollection {
+    // FIXME: should be FxHashMap<FileId, Vec<ra_id::Diagnostic>>
+    pub(crate) native: FxHashMap<FileId, Vec<lsp_types::Diagnostic>>,
+    // FIXME: should be Vec<flycheck::Diagnostic>
+    pub(crate) check: FxHashMap<FileId, Vec<lsp_types::Diagnostic>>,
+    pub(crate) check_fixes: CheckFixes,
+    changes: FxHashSet<FileId>,
 }
 
-#[derive(Debug)]
-pub enum DiagnosticTask {
-    ClearCheck,
-    AddCheck(FileId, Diagnostic, Vec<lsp_ext::CodeAction>),
-    SetNative(FileId, Vec<Diagnostic>),
+#[derive(Debug, Clone)]
+pub(crate) struct Fix {
+    pub(crate) range: lsp_types::Range,
+    pub(crate) action: lsp_ext::CodeAction,
 }
 
 impl DiagnosticCollection {
-    pub fn clear_check(&mut self) -> Vec<FileId> {
+    pub(crate) fn clear_check(&mut self) {
         Arc::make_mut(&mut self.check_fixes).clear();
-        self.check.drain().map(|(key, _value)| key).collect()
+        self.changes.extend(self.check.drain().map(|(key, _value)| key))
     }
 
-    pub fn add_check_diagnostic(
+    pub(crate) fn add_check_diagnostic(
         &mut self,
         file_id: FileId,
-        diagnostic: Diagnostic,
+        diagnostic: lsp_types::Diagnostic,
         fixes: Vec<lsp_ext::CodeAction>,
     ) {
         let diagnostics = self.check.entry(file_id).or_default();
@@ -55,34 +57,36 @@ impl DiagnosticCollection {
             .or_default()
             .extend(fixes.into_iter().map(|action| Fix { range: diagnostic.range, action }));
         diagnostics.push(diagnostic);
+        self.changes.insert(file_id);
     }
 
-    pub fn set_native_diagnostics(&mut self, file_id: FileId, diagnostics: Vec<Diagnostic>) {
+    pub(crate) fn set_native_diagnostics(
+        &mut self,
+        file_id: FileId,
+        diagnostics: Vec<lsp_types::Diagnostic>,
+    ) {
         self.native.insert(file_id, diagnostics);
+        self.changes.insert(file_id);
     }
 
-    pub fn diagnostics_for(&self, file_id: FileId) -> impl Iterator<Item = &Diagnostic> {
+    pub(crate) fn diagnostics_for(
+        &self,
+        file_id: FileId,
+    ) -> impl Iterator<Item = &lsp_types::Diagnostic> {
         let native = self.native.get(&file_id).into_iter().flatten();
         let check = self.check.get(&file_id).into_iter().flatten();
         native.chain(check)
     }
 
-    pub fn handle_task(&mut self, task: DiagnosticTask) -> Vec<FileId> {
-        match task {
-            DiagnosticTask::ClearCheck => self.clear_check(),
-            DiagnosticTask::AddCheck(file_id, diagnostic, fixes) => {
-                self.add_check_diagnostic(file_id, diagnostic, fixes);
-                vec![file_id]
-            }
-            DiagnosticTask::SetNative(file_id, diagnostics) => {
-                self.set_native_diagnostics(file_id, diagnostics);
-                vec![file_id]
-            }
+    pub(crate) fn take_changes(&mut self) -> Option<FxHashSet<FileId>> {
+        if self.changes.is_empty() {
+            return None;
         }
+        Some(mem::take(&mut self.changes))
     }
 }
 
-fn are_diagnostics_equal(left: &Diagnostic, right: &Diagnostic) -> bool {
+fn are_diagnostics_equal(left: &lsp_types::Diagnostic, right: &lsp_types::Diagnostic) -> bool {
     left.source == right.source
         && left.severity == right.severity
         && left.range == right.range
diff --git a/crates/rust-analyzer/src/diagnostics/to_proto.rs b/crates/rust-analyzer/src/diagnostics/to_proto.rs
index a500d670a..7be3ef984 100644
--- a/crates/rust-analyzer/src/diagnostics/to_proto.rs
+++ b/crates/rust-analyzer/src/diagnostics/to_proto.rs
@@ -1,28 +1,34 @@
 //! This module provides the functionality needed to convert diagnostics from
 //! `cargo check` json format to the LSP diagnostic format.
-use std::{
-    collections::HashMap,
-    path::{Component, Path, Prefix},
-    str::FromStr,
-};
+use std::{collections::HashMap, path::Path};
 
-use lsp_types::{
-    Diagnostic, DiagnosticRelatedInformation, DiagnosticSeverity, DiagnosticTag, Location,
-    NumberOrString, Position, Range, TextEdit, Url,
-};
-use ra_flycheck::{Applicability, DiagnosticLevel, DiagnosticSpan, DiagnosticSpanMacroExpansion};
+use flycheck::{Applicability, DiagnosticLevel, DiagnosticSpan};
 use stdx::format_to;
 
-use crate::{lsp_ext, Result};
+use crate::{lsp_ext, to_proto::url_from_abs_path};
 
-/// Converts a Rust level string to a LSP severity
-fn map_level_to_severity(val: DiagnosticLevel) -> Option<DiagnosticSeverity> {
-    let res = match val {
-        DiagnosticLevel::Ice => DiagnosticSeverity::Error,
-        DiagnosticLevel::Error => DiagnosticSeverity::Error,
-        DiagnosticLevel::Warning => DiagnosticSeverity::Warning,
-        DiagnosticLevel::Note => DiagnosticSeverity::Information,
-        DiagnosticLevel::Help => DiagnosticSeverity::Hint,
+use super::DiagnosticsConfig;
+
+/// Determines the LSP severity from a diagnostic
+fn diagnostic_severity(
+    config: &DiagnosticsConfig,
+    level: flycheck::DiagnosticLevel,
+    code: Option<flycheck::DiagnosticCode>,
+) -> Option<lsp_types::DiagnosticSeverity> {
+    let res = match level {
+        DiagnosticLevel::Ice => lsp_types::DiagnosticSeverity::Error,
+        DiagnosticLevel::Error => lsp_types::DiagnosticSeverity::Error,
+        DiagnosticLevel::Warning => match &code {
+            Some(code) if config.warnings_as_hint.contains(&code.code) => {
+                lsp_types::DiagnosticSeverity::Hint
+            }
+            Some(code) if config.warnings_as_info.contains(&code.code) => {
+                lsp_types::DiagnosticSeverity::Information
+            }
+            _ => lsp_types::DiagnosticSeverity::Warning,
+        },
+        DiagnosticLevel::Note => lsp_types::DiagnosticSeverity::Information,
+        DiagnosticLevel::Help => lsp_types::DiagnosticSeverity::Hint,
         DiagnosticLevel::Unknown => return None,
     };
     Some(res)
@@ -33,90 +39,50 @@ fn is_from_macro(file_name: &str) -> bool {
     file_name.starts_with('<') && file_name.ends_with('>')
 }
 
-/// Converts a Rust macro span to a LSP location recursively
-fn map_macro_span_to_location(
-    span_macro: &DiagnosticSpanMacroExpansion,
-    workspace_root: &Path,
-) -> Option<Location> {
-    if !is_from_macro(&span_macro.span.file_name) {
-        return Some(map_span_to_location(&span_macro.span, workspace_root));
-    }
-
-    if let Some(expansion) = &span_macro.span.expansion {
-        return map_macro_span_to_location(&expansion, workspace_root);
-    }
-
-    None
-}
-
 /// Converts a Rust span to a LSP location, resolving macro expansion site if neccesary
-fn map_span_to_location(span: &DiagnosticSpan, workspace_root: &Path) -> Location {
-    if span.expansion.is_some() {
-        let expansion = span.expansion.as_ref().unwrap();
-        if let Some(macro_range) = map_macro_span_to_location(&expansion, workspace_root) {
-            return macro_range;
-        }
+fn location(workspace_root: &Path, span: &DiagnosticSpan) -> lsp_types::Location {
+    let mut span = span.clone();
+    while let Some(expansion) = span.expansion {
+        span = expansion.span;
     }
-
-    map_span_to_location_naive(span, workspace_root)
+    return location_naive(workspace_root, &span);
 }
 
 /// Converts a Rust span to a LSP location
-fn map_span_to_location_naive(span: &DiagnosticSpan, workspace_root: &Path) -> Location {
-    let mut file_name = workspace_root.to_path_buf();
-    file_name.push(&span.file_name);
-    let uri = url_from_path_with_drive_lowercasing(file_name).unwrap();
+fn location_naive(workspace_root: &Path, span: &DiagnosticSpan) -> lsp_types::Location {
+    let file_name = workspace_root.join(&span.file_name);
+    let uri = url_from_abs_path(&file_name);
 
     // FIXME: this doesn't handle UTF16 offsets correctly
-    let range = Range::new(
-        Position::new(span.line_start as u64 - 1, span.column_start as u64 - 1),
-        Position::new(span.line_end as u64 - 1, span.column_end as u64 - 1),
+    let range = lsp_types::Range::new(
+        lsp_types::Position::new(span.line_start as u64 - 1, span.column_start as u64 - 1),
+        lsp_types::Position::new(span.line_end as u64 - 1, span.column_end as u64 - 1),
     );
 
-    Location { uri, range }
+    lsp_types::Location { uri, range }
 }
 
-/// Converts a secondary Rust span to a LSP related information
+/// Converts a secondary Rust span to a LSP related inflocation(ormation
 ///
 /// If the span is unlabelled this will return `None`.
-fn map_secondary_span_to_related(
-    span: &DiagnosticSpan,
+fn diagnostic_related_information(
     workspace_root: &Path,
-) -> Option<DiagnosticRelatedInformation> {
+    span: &DiagnosticSpan,
+) -> Option<lsp_types::DiagnosticRelatedInformation> {
     let message = span.label.clone()?;
-    let location = map_span_to_location(span, workspace_root);
-    Some(DiagnosticRelatedInformation { location, message })
-}
-
-/// Determines if diagnostic is related to unused code
-fn is_unused_or_unnecessary(rd: &ra_flycheck::Diagnostic) -> bool {
-    match &rd.code {
-        Some(code) => match code.code.as_str() {
-            "dead_code" | "unknown_lints" | "unreachable_code" | "unused_attributes"
-            | "unused_imports" | "unused_macros" | "unused_variables" => true,
-            _ => false,
-        },
-        None => false,
-    }
-}
-
-/// Determines if diagnostic is related to deprecated code
-fn is_deprecated(rd: &ra_flycheck::Diagnostic) -> bool {
-    match &rd.code {
-        Some(code) => code.code.as_str() == "deprecated",
-        None => false,
-    }
+    let location = location(workspace_root, span);
+    Some(lsp_types::DiagnosticRelatedInformation { location, message })
 }
 
 enum MappedRustChildDiagnostic {
-    Related(DiagnosticRelatedInformation),
+    Related(lsp_types::DiagnosticRelatedInformation),
     SuggestedFix(lsp_ext::CodeAction),
     MessageLine(String),
 }
 
 fn map_rust_child_diagnostic(
-    rd: &ra_flycheck::Diagnostic,
     workspace_root: &Path,
+    rd: &flycheck::Diagnostic,
 ) -> MappedRustChildDiagnostic {
     let spans: Vec<&DiagnosticSpan> = rd.spans.iter().filter(|s| s.is_primary).collect();
     if spans.is_empty() {
@@ -125,43 +91,42 @@ fn map_rust_child_diagnostic(
         return MappedRustChildDiagnostic::MessageLine(rd.message.clone());
     }
 
-    let mut edit_map: HashMap<Url, Vec<TextEdit>> = HashMap::new();
+    let mut edit_map: HashMap<lsp_types::Url, Vec<lsp_types::TextEdit>> = HashMap::new();
     for &span in &spans {
-        match (&span.suggestion_applicability, &span.suggested_replacement) {
-            (Some(Applicability::MachineApplicable), Some(suggested_replacement)) => {
-                let location = map_span_to_location(span, workspace_root);
-                let edit = TextEdit::new(location.range, suggested_replacement.clone());
-                edit_map.entry(location.uri).or_default().push(edit);
-            }
-            _ => {}
+        if let (Some(Applicability::MachineApplicable), Some(suggested_replacement)) =
+            (&span.suggestion_applicability, &span.suggested_replacement)
+        {
+            let location = location(workspace_root, span);
+            let edit = lsp_types::TextEdit::new(location.range, suggested_replacement.clone());
+            edit_map.entry(location.uri).or_default().push(edit);
         }
     }
 
     if edit_map.is_empty() {
-        MappedRustChildDiagnostic::Related(DiagnosticRelatedInformation {
-            location: map_span_to_location(spans[0], workspace_root),
+        MappedRustChildDiagnostic::Related(lsp_types::DiagnosticRelatedInformation {
+            location: location(workspace_root, spans[0]),
             message: rd.message.clone(),
         })
     } else {
         MappedRustChildDiagnostic::SuggestedFix(lsp_ext::CodeAction {
             title: rd.message.clone(),
+            id: None,
             group: None,
-            kind: Some("quickfix".to_string()),
+            kind: Some(lsp_types::CodeActionKind::QUICKFIX),
             edit: Some(lsp_ext::SnippetWorkspaceEdit {
                 // FIXME: there's no good reason to use edit_map here....
                 changes: Some(edit_map),
                 document_changes: None,
             }),
-            command: None,
         })
     }
 }
 
 #[derive(Debug)]
 pub(crate) struct MappedRustDiagnostic {
-    pub location: Location,
-    pub diagnostic: Diagnostic,
-    pub fixes: Vec<lsp_ext::CodeAction>,
+    pub(crate) url: lsp_types::Url,
+    pub(crate) diagnostic: lsp_types::Diagnostic,
+    pub(crate) fixes: Vec<lsp_ext::CodeAction>,
 }
 
 /// Converts a Rust root diagnostic to LSP form
@@ -175,7 +140,8 @@ pub(crate) struct MappedRustDiagnostic {
 ///
 /// If the diagnostic has no primary span this will return `None`
 pub(crate) fn map_rust_diagnostic_to_lsp(
-    rd: &ra_flycheck::Diagnostic,
+    config: &DiagnosticsConfig,
+    rd: &flycheck::Diagnostic,
     workspace_root: &Path,
 ) -> Vec<MappedRustDiagnostic> {
     let primary_spans: Vec<&DiagnosticSpan> = rd.spans.iter().filter(|s| s.is_primary).collect();
@@ -183,7 +149,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
         return Vec::new();
     }
 
-    let severity = map_level_to_severity(rd.level);
+    let severity = diagnostic_severity(config, rd.level.clone(), rd.code.clone());
 
     let mut source = String::from("rustc");
     let mut code = rd.code.as_ref().map(|c| c.code.clone());
@@ -201,7 +167,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
     let mut tags = Vec::new();
 
     for secondary_span in rd.spans.iter().filter(|s| !s.is_primary) {
-        let related = map_secondary_span_to_related(secondary_span, workspace_root);
+        let related = diagnostic_related_information(workspace_root, secondary_span);
         if let Some(related) = related {
             related_information.push(related);
         }
@@ -210,7 +176,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
     let mut fixes = Vec::new();
     let mut message = rd.message.clone();
     for child in &rd.children {
-        let child = map_rust_child_diagnostic(&child, workspace_root);
+        let child = map_rust_child_diagnostic(workspace_root, &child);
         match child {
             MappedRustChildDiagnostic::Related(related) => related_information.push(related),
             MappedRustChildDiagnostic::SuggestedFix(code_action) => fixes.push(code_action),
@@ -224,18 +190,30 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
         }
     }
 
-    if is_unused_or_unnecessary(rd) {
-        tags.push(DiagnosticTag::Unnecessary);
-    }
+    if let Some(code) = &rd.code {
+        let code = code.code.as_str();
+        if matches!(
+            code,
+            "dead_code"
+                | "unknown_lints"
+                | "unreachable_code"
+                | "unused_attributes"
+                | "unused_imports"
+                | "unused_macros"
+                | "unused_variables"
+        ) {
+            tags.push(lsp_types::DiagnosticTag::Unnecessary);
+        }
 
-    if is_deprecated(rd) {
-        tags.push(DiagnosticTag::Deprecated);
+        if matches!(code, "deprecated") {
+            tags.push(lsp_types::DiagnosticTag::Deprecated);
+        }
     }
 
     primary_spans
         .iter()
         .map(|primary_span| {
-            let location = map_span_to_location(&primary_span, workspace_root);
+            let location = location(workspace_root, &primary_span);
 
             let mut message = message.clone();
             if needs_primary_span_label {
@@ -247,17 +225,16 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
             // If error occurs from macro expansion, add related info pointing to
             // where the error originated
             if !is_from_macro(&primary_span.file_name) && primary_span.expansion.is_some() {
-                let def_loc = map_span_to_location_naive(&primary_span, workspace_root);
-                related_information.push(DiagnosticRelatedInformation {
-                    location: def_loc,
+                related_information.push(lsp_types::DiagnosticRelatedInformation {
+                    location: location_naive(workspace_root, &primary_span),
                     message: "Error originated from macro here".to_string(),
                 });
             }
 
-            let diagnostic = Diagnostic {
+            let diagnostic = lsp_types::Diagnostic {
                 range: location.range,
                 severity,
-                code: code.clone().map(NumberOrString::String),
+                code: code.clone().map(lsp_types::NumberOrString::String),
                 source: Some(source.clone()),
                 message,
                 related_information: if related_information.is_empty() {
@@ -268,77 +245,32 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
                 tags: if tags.is_empty() { None } else { Some(tags.clone()) },
             };
 
-            MappedRustDiagnostic { location, diagnostic, fixes: fixes.clone() }
+            MappedRustDiagnostic { url: location.uri, diagnostic, fixes: fixes.clone() }
         })
         .collect()
 }
 
-/// Returns a `Url` object from a given path, will lowercase drive letters if present.
-/// This will only happen when processing windows paths.
-///
-/// When processing non-windows path, this is essentially the same as `Url::from_file_path`.
-pub fn url_from_path_with_drive_lowercasing(path: impl AsRef<Path>) -> Result<Url> {
-    let component_has_windows_drive = path.as_ref().components().any(|comp| {
-        if let Component::Prefix(c) = comp {
-            return matches!(c.kind(), Prefix::Disk(_) | Prefix::VerbatimDisk(_));
-        }
-        false
-    });
-
-    // VSCode expects drive letters to be lowercased, where rust will uppercase the drive letters.
-    let res = if component_has_windows_drive {
-        let url_original = Url::from_file_path(&path)
-            .map_err(|_| format!("can't convert path to url: {}", path.as_ref().display()))?;
-
-        let drive_partition: Vec<&str> = url_original.as_str().rsplitn(2, ':').collect();
-
-        // There is a drive partition, but we never found a colon.
-        // This should not happen, but in this case we just pass it through.
-        if drive_partition.len() == 1 {
-            return Ok(url_original);
-        }
-
-        let joined = drive_partition[1].to_ascii_lowercase() + ":" + drive_partition[0];
-        let url = Url::from_str(&joined).expect("This came from a valid `Url`");
-
-        url
-    } else {
-        Url::from_file_path(&path)
-            .map_err(|_| format!("can't convert path to url: {}", path.as_ref().display()))?
-    };
-    Ok(res)
-}
-
 #[cfg(test)]
+#[cfg(not(windows))]
 mod tests {
     use super::*;
 
-    // `Url` is not able to parse windows paths on unix machines.
-    #[test]
-    #[cfg(target_os = "windows")]
-    fn test_lowercase_drive_letter_with_drive() {
-        let url = url_from_path_with_drive_lowercasing("C:\\Test").unwrap();
+    use expect::{expect_file, ExpectFile};
 
-        assert_eq!(url.to_string(), "file:///c:/Test");
+    fn check(diagnostics_json: &str, expect: ExpectFile) {
+        check_with_config(DiagnosticsConfig::default(), diagnostics_json, expect)
     }
 
-    #[test]
-    #[cfg(target_os = "windows")]
-    fn test_drive_without_colon_passthrough() {
-        let url = url_from_path_with_drive_lowercasing(r#"\\localhost\C$\my_dir"#).unwrap();
-
-        assert_eq!(url.to_string(), "file://localhost/C$/my_dir");
-    }
-
-    #[cfg(not(windows))]
-    fn parse_diagnostic(val: &str) -> ra_flycheck::Diagnostic {
-        serde_json::from_str::<ra_flycheck::Diagnostic>(val).unwrap()
+    fn check_with_config(config: DiagnosticsConfig, diagnostics_json: &str, expect: ExpectFile) {
+        let diagnostic: flycheck::Diagnostic = serde_json::from_str(diagnostics_json).unwrap();
+        let workspace_root = Path::new("/test/");
+        let actual = map_rust_diagnostic_to_lsp(&config, &diagnostic, workspace_root);
+        expect.assert_debug_eq(&actual)
     }
 
     #[test]
-    #[cfg(not(windows))]
-    fn snap_rustc_incompatible_type_for_trait() {
-        let diag = parse_diagnostic(
+    fn rustc_incompatible_type_for_trait() {
+        check(
             r##"{
                 "message": "method `next` has an incompatible type for trait",
                 "code": {
@@ -382,17 +314,97 @@ mod tests {
                 "rendered": "error[E0053]: method `next` has an incompatible type for trait\n  --> compiler/ty/list_iter.rs:52:5\n   |\n52 |     fn next(&self) -> Option<&'list ty::Ref<M>> {\n   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ types differ in mutability\n   |\n   = note: expected type `fn(&mut ty::list_iter::ListIterator<'list, M>) -> std::option::Option<&ty::Ref<M>>`\n              found type `fn(&ty::list_iter::ListIterator<'list, M>) -> std::option::Option<&'list ty::Ref<M>>`\n\n"
             }
             "##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_incompatible_type_for_trait.txt"],
         );
+    }
 
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
+    #[test]
+    fn rustc_unused_variable() {
+        check(
+            r##"{
+    "message": "unused variable: `foo`",
+    "code": {
+        "code": "unused_variables",
+        "explanation": null
+    },
+    "level": "warning",
+    "spans": [
+        {
+            "file_name": "driver/subcommand/repl.rs",
+            "byte_start": 9228,
+            "byte_end": 9231,
+            "line_start": 291,
+            "line_end": 291,
+            "column_start": 9,
+            "column_end": 12,
+            "is_primary": true,
+            "text": [
+                {
+                    "text": "    let foo = 42;",
+                    "highlight_start": 9,
+                    "highlight_end": 12
+                }
+            ],
+            "label": null,
+            "suggested_replacement": null,
+            "suggestion_applicability": null,
+            "expansion": null
+        }
+    ],
+    "children": [
+        {
+            "message": "#[warn(unused_variables)] on by default",
+            "code": null,
+            "level": "note",
+            "spans": [],
+            "children": [],
+            "rendered": null
+        },
+        {
+            "message": "consider prefixing with an underscore",
+            "code": null,
+            "level": "help",
+            "spans": [
+                {
+                    "file_name": "driver/subcommand/repl.rs",
+                    "byte_start": 9228,
+                    "byte_end": 9231,
+                    "line_start": 291,
+                    "line_end": 291,
+                    "column_start": 9,
+                    "column_end": 12,
+                    "is_primary": true,
+                    "text": [
+                        {
+                            "text": "    let foo = 42;",
+                            "highlight_start": 9,
+                            "highlight_end": 12
+                        }
+                    ],
+                    "label": null,
+                    "suggested_replacement": "_foo",
+                    "suggestion_applicability": "MachineApplicable",
+                    "expansion": null
+                }
+            ],
+            "children": [],
+            "rendered": null
+        }
+    ],
+    "rendered": "warning: unused variable: `foo`\n   --> driver/subcommand/repl.rs:291:9\n    |\n291 |     let foo = 42;\n    |         ^^^ help: consider prefixing with an underscore: `_foo`\n    |\n    = note: #[warn(unused_variables)] on by default\n\n"
+    }"##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_unused_variable.txt"],
+        );
     }
 
     #[test]
     #[cfg(not(windows))]
-    fn snap_rustc_unused_variable() {
-        let diag = parse_diagnostic(
+    fn rustc_unused_variable_as_info() {
+        check_with_config(
+            DiagnosticsConfig {
+                warnings_as_info: vec!["unused_variables".to_string()],
+                ..DiagnosticsConfig::default()
+            },
             r##"{
     "message": "unused variable: `foo`",
     "code": {
@@ -465,17 +477,97 @@ mod tests {
     ],
     "rendered": "warning: unused variable: `foo`\n   --> driver/subcommand/repl.rs:291:9\n    |\n291 |     let foo = 42;\n    |         ^^^ help: consider prefixing with an underscore: `_foo`\n    |\n    = note: #[warn(unused_variables)] on by default\n\n"
     }"##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_unused_variable_as_info.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
     #[cfg(not(windows))]
-    fn snap_rustc_wrong_number_of_parameters() {
-        let diag = parse_diagnostic(
+    fn rustc_unused_variable_as_hint() {
+        check_with_config(
+            DiagnosticsConfig {
+                warnings_as_hint: vec!["unused_variables".to_string()],
+                ..DiagnosticsConfig::default()
+            },
+            r##"{
+    "message": "unused variable: `foo`",
+    "code": {
+        "code": "unused_variables",
+        "explanation": null
+    },
+    "level": "warning",
+    "spans": [
+        {
+            "file_name": "driver/subcommand/repl.rs",
+            "byte_start": 9228,
+            "byte_end": 9231,
+            "line_start": 291,
+            "line_end": 291,
+            "column_start": 9,
+            "column_end": 12,
+            "is_primary": true,
+            "text": [
+                {
+                    "text": "    let foo = 42;",
+                    "highlight_start": 9,
+                    "highlight_end": 12
+                }
+            ],
+            "label": null,
+            "suggested_replacement": null,
+            "suggestion_applicability": null,
+            "expansion": null
+        }
+    ],
+    "children": [
+        {
+            "message": "#[warn(unused_variables)] on by default",
+            "code": null,
+            "level": "note",
+            "spans": [],
+            "children": [],
+            "rendered": null
+        },
+        {
+            "message": "consider prefixing with an underscore",
+            "code": null,
+            "level": "help",
+            "spans": [
+                {
+                    "file_name": "driver/subcommand/repl.rs",
+                    "byte_start": 9228,
+                    "byte_end": 9231,
+                    "line_start": 291,
+                    "line_end": 291,
+                    "column_start": 9,
+                    "column_end": 12,
+                    "is_primary": true,
+                    "text": [
+                        {
+                            "text": "    let foo = 42;",
+                            "highlight_start": 9,
+                            "highlight_end": 12
+                        }
+                    ],
+                    "label": null,
+                    "suggested_replacement": "_foo",
+                    "suggestion_applicability": "MachineApplicable",
+                    "expansion": null
+                }
+            ],
+            "children": [],
+            "rendered": null
+        }
+    ],
+    "rendered": "warning: unused variable: `foo`\n   --> driver/subcommand/repl.rs:291:9\n    |\n291 |     let foo = 42;\n    |         ^^^ help: consider prefixing with an underscore: `_foo`\n    |\n    = note: #[warn(unused_variables)] on by default\n\n"
+    }"##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_unused_variable_as_hint.txt"],
+        );
+    }
+
+    #[test]
+    fn rustc_wrong_number_of_parameters() {
+        check(
             r##"{
     "message": "this function takes 2 parameters but 3 parameters were supplied",
     "code": {
@@ -590,17 +682,13 @@ mod tests {
     "children": [],
     "rendered": "error[E0061]: this function takes 2 parameters but 3 parameters were supplied\n   --> compiler/ty/select.rs:104:18\n    |\n104 |               self.add_evidence(target_fixed, evidence_fixed, false);\n    |                    ^^^^^^^^^^^^ expected 2 parameters\n...\n219 | /     pub fn add_evidence(\n220 | |         &mut self,\n221 | |         target_poly: &ty::Ref<ty::Poly>,\n222 | |         evidence_poly: &ty::Ref<ty::Poly>,\n...   |\n230 | |         }\n231 | |     }\n    | |_____- defined here\n\n"
     }"##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_wrong_number_of_parameters.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
-    #[cfg(not(windows))]
-    fn snap_clippy_pass_by_ref() {
-        let diag = parse_diagnostic(
+    fn clippy_pass_by_ref() {
+        check(
             r##"{
     "message": "this argument is passed by reference, but would be more efficient if passed by value",
     "code": {
@@ -711,17 +799,13 @@ mod tests {
     ],
     "rendered": "warning: this argument is passed by reference, but would be more efficient if passed by value\n  --> compiler/mir/tagset.rs:42:24\n   |\n42 |     pub fn is_disjoint(&self, other: Self) -> bool {\n   |                        ^^^^^ help: consider passing by value instead: `self`\n   |\nnote: lint level defined here\n  --> compiler/lib.rs:1:9\n   |\n1  | #![warn(clippy::all)]\n   |         ^^^^^^^^^^^\n   = note: #[warn(clippy::trivially_copy_pass_by_ref)] implied by #[warn(clippy::all)]\n   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#trivially_copy_pass_by_ref\n\n"
     }"##,
+            expect_file!["crates/rust-analyzer/test_data/clippy_pass_by_ref.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
-    #[cfg(not(windows))]
-    fn snap_rustc_mismatched_type() {
-        let diag = parse_diagnostic(
+    fn rustc_mismatched_type() {
+        check(
             r##"{
     "message": "mismatched types",
     "code": {
@@ -755,17 +839,13 @@ mod tests {
     "children": [],
     "rendered": "error[E0308]: mismatched types\n  --> runtime/compiler_support.rs:48:65\n   |\n48 |     let layout = alloc::Layout::from_size_align_unchecked(size, align);\n   |                                                                 ^^^^^ expected usize, found u32\n\n"
     }"##,
+            expect_file!["crates/rust-analyzer/test_data/rustc_mismatched_type.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
-    #[cfg(not(windows))]
-    fn snap_handles_macro_location() {
-        let diag = parse_diagnostic(
+    fn handles_macro_location() {
+        check(
             r##"{
     "rendered": "error[E0277]: can't compare `{integer}` with `&str`\n --> src/main.rs:2:5\n  |\n2 |     assert_eq!(1, \"love\");\n  |     ^^^^^^^^^^^^^^^^^^^^^^ no implementation for `{integer} == &str`\n  |\n  = help: the trait `std::cmp::PartialEq<&str>` is not implemented for `{integer}`\n  = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)\n\n",
     "children": [
@@ -1027,17 +1107,13 @@ mod tests {
         }
     ]
     }"##,
+            expect_file!["crates/rust-analyzer/test_data/handles_macro_location.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
-    #[cfg(not(windows))]
-    fn snap_macro_compiler_error() {
-        let diag = parse_diagnostic(
+    fn macro_compiler_error() {
+        check(
             r##"{
         "rendered": "error: Please register your known path in the path module\n   --> crates/ra_hir_def/src/path.rs:265:9\n    |\n265 |         compile_error!(\"Please register your known path in the path module\")\n    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n    | \n   ::: crates/ra_hir_def/src/data.rs:80:16\n    |\n80  |     let path = path![std::future::Future];\n    |                -------------------------- in this macro invocation\n\n",
         "children": [],
@@ -1257,17 +1333,13 @@ mod tests {
         ]
     }
             "##,
+            expect_file!["crates/rust-analyzer/test_data/macro_compiler_error.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 
     #[test]
-    #[cfg(not(windows))]
     fn snap_multi_line_fix() {
-        let diag = parse_diagnostic(
+        check(
             r##"{
                 "rendered": "warning: returning the result of a let binding from a block\n --> src/main.rs:4:5\n  |\n3 |     let a = (0..10).collect();\n  |     -------------------------- unnecessary let binding\n4 |     a\n  |     ^\n  |\n  = note: `#[warn(clippy::let_and_return)]` on by default\n  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return\nhelp: return the expression directly\n  |\n3 |     \n4 |     (0..10).collect()\n  |\n\n",
                 "children": [
@@ -1391,10 +1463,7 @@ mod tests {
                 ]
             }
             "##,
+            expect_file!["crates/rust-analyzer/test_data/snap_multi_line_fix.txt"],
         );
-
-        let workspace_root = Path::new("/test/");
-        let diag = map_rust_diagnostic_to_lsp(&diag, workspace_root);
-        insta::assert_debug_snapshot!(diag);
     }
 }
diff --git a/crates/rust-analyzer/src/dispatch.rs b/crates/rust-analyzer/src/dispatch.rs
new file mode 100644
index 000000000..891fdb96d
--- /dev/null
+++ b/crates/rust-analyzer/src/dispatch.rs
@@ -0,0 +1,170 @@
+//! A visitor for downcasting arbitrary request (JSON) into a specific type.
+use std::panic;
+
+use serde::{de::DeserializeOwned, Serialize};
+
+use crate::{
+    global_state::{GlobalState, GlobalStateSnapshot},
+    lsp_utils::is_canceled,
+    main_loop::Task,
+    LspError, Result,
+};
+
+pub(crate) struct RequestDispatcher<'a> {
+    pub(crate) req: Option<lsp_server::Request>,
+    pub(crate) global_state: &'a mut GlobalState,
+}
+
+impl<'a> RequestDispatcher<'a> {
+    /// Dispatches the request onto the current thread
+    pub(crate) fn on_sync<R>(
+        &mut self,
+        f: fn(&mut GlobalState, R::Params) -> Result<R::Result>,
+    ) -> Result<&mut Self>
+    where
+        R: lsp_types::request::Request + 'static,
+        R::Params: DeserializeOwned + panic::UnwindSafe + 'static,
+        R::Result: Serialize + 'static,
+    {
+        let (id, params) = match self.parse::<R>() {
+            Some(it) => it,
+            None => {
+                return Ok(self);
+            }
+        };
+        let world = panic::AssertUnwindSafe(&mut *self.global_state);
+        let response = panic::catch_unwind(move || {
+            let result = f(world.0, params);
+            result_to_response::<R>(id, result)
+        })
+        .map_err(|_| format!("sync task {:?} panicked", R::METHOD))?;
+        self.global_state.respond(response);
+        Ok(self)
+    }
+
+    /// Dispatches the request onto thread pool
+    pub(crate) fn on<R>(
+        &mut self,
+        f: fn(GlobalStateSnapshot, R::Params) -> Result<R::Result>,
+    ) -> Result<&mut Self>
+    where
+        R: lsp_types::request::Request + 'static,
+        R::Params: DeserializeOwned + Send + 'static,
+        R::Result: Serialize + 'static,
+    {
+        let (id, params) = match self.parse::<R>() {
+            Some(it) => it,
+            None => {
+                return Ok(self);
+            }
+        };
+
+        self.global_state.task_pool.handle.spawn({
+            let world = self.global_state.snapshot();
+            move || {
+                let result = f(world, params);
+                Task::Response(result_to_response::<R>(id, result))
+            }
+        });
+
+        Ok(self)
+    }
+
+    pub(crate) fn finish(&mut self) {
+        if let Some(req) = self.req.take() {
+            log::error!("unknown request: {:?}", req);
+            let response = lsp_server::Response::new_err(
+                req.id,
+                lsp_server::ErrorCode::MethodNotFound as i32,
+                "unknown request".to_string(),
+            );
+            self.global_state.respond(response)
+        }
+    }
+
+    fn parse<R>(&mut self) -> Option<(lsp_server::RequestId, R::Params)>
+    where
+        R: lsp_types::request::Request + 'static,
+        R::Params: DeserializeOwned + 'static,
+    {
+        let req = self.req.take()?;
+        let (id, params) = match req.extract::<R::Params>(R::METHOD) {
+            Ok(it) => it,
+            Err(req) => {
+                self.req = Some(req);
+                return None;
+            }
+        };
+        Some((id, params))
+    }
+}
+
+fn result_to_response<R>(
+    id: lsp_server::RequestId,
+    result: Result<R::Result>,
+) -> lsp_server::Response
+where
+    R: lsp_types::request::Request + 'static,
+    R::Params: DeserializeOwned + 'static,
+    R::Result: Serialize + 'static,
+{
+    match result {
+        Ok(resp) => lsp_server::Response::new_ok(id, &resp),
+        Err(e) => match e.downcast::<LspError>() {
+            Ok(lsp_error) => lsp_server::Response::new_err(id, lsp_error.code, lsp_error.message),
+            Err(e) => {
+                if is_canceled(&*e) {
+                    lsp_server::Response::new_err(
+                        id,
+                        lsp_server::ErrorCode::ContentModified as i32,
+                        "content modified".to_string(),
+                    )
+                } else {
+                    lsp_server::Response::new_err(
+                        id,
+                        lsp_server::ErrorCode::InternalError as i32,
+                        e.to_string(),
+                    )
+                }
+            }
+        },
+    }
+}
+
+pub(crate) struct NotificationDispatcher<'a> {
+    pub(crate) not: Option<lsp_server::Notification>,
+    pub(crate) global_state: &'a mut GlobalState,
+}
+
+impl<'a> NotificationDispatcher<'a> {
+    pub(crate) fn on<N>(
+        &mut self,
+        f: fn(&mut GlobalState, N::Params) -> Result<()>,
+    ) -> Result<&mut Self>
+    where
+        N: lsp_types::notification::Notification + 'static,
+        N::Params: DeserializeOwned + Send + 'static,
+    {
+        let not = match self.not.take() {
+            Some(it) => it,
+            None => return Ok(self),
+        };
+        let params = match not.extract::<N::Params>(N::METHOD) {
+            Ok(it) => it,
+            Err(not) => {
+                self.not = Some(not);
+                return Ok(self);
+            }
+        };
+        f(self.global_state, params)?;
+        Ok(self)
+    }
+
+    pub(crate) fn finish(&mut self) {
+        if let Some(not) = &self.not {
+            if !not.method.starts_with("$/") {
+                log::error!("unhandled notification: {:?}", not);
+            }
+        }
+    }
+}
diff --git a/crates/rust-analyzer/src/from_proto.rs b/crates/rust-analyzer/src/from_proto.rs
index 4bb16a496..9f8ce3b99 100644
--- a/crates/rust-analyzer/src/from_proto.rs
+++ b/crates/rust-analyzer/src/from_proto.rs
@@ -1,9 +1,21 @@
 //! Conversion lsp_types types to rust-analyzer specific ones.
+use std::convert::TryFrom;
+
 use ra_db::{FileId, FilePosition, FileRange};
-use ra_ide::{LineCol, LineIndex};
+use ra_ide::{AssistKind, LineCol, LineIndex};
 use ra_syntax::{TextRange, TextSize};
+use vfs::AbsPathBuf;
+
+use crate::{global_state::GlobalStateSnapshot, Result};
+
+pub(crate) fn abs_path(url: &lsp_types::Url) -> Result<AbsPathBuf> {
+    let path = url.to_file_path().map_err(|()| "url is not a file")?;
+    Ok(AbsPathBuf::try_from(path).unwrap())
+}
 
-use crate::{world::WorldSnapshot, Result};
+pub(crate) fn vfs_path(url: &lsp_types::Url) -> Result<vfs::VfsPath> {
+    abs_path(url).map(vfs::VfsPath::from)
+}
 
 pub(crate) fn offset(line_index: &LineIndex, position: lsp_types::Position) -> TextSize {
     let line_col = LineCol { line: position.line as u32, col_utf16: position.character as u32 };
@@ -16,27 +28,41 @@ pub(crate) fn text_range(line_index: &LineIndex, range: lsp_types::Range) -> Tex
     TextRange::new(start, end)
 }
 
-pub(crate) fn file_id(world: &WorldSnapshot, url: &lsp_types::Url) -> Result<FileId> {
-    world.uri_to_file_id(url)
+pub(crate) fn file_id(world: &GlobalStateSnapshot, url: &lsp_types::Url) -> Result<FileId> {
+    world.url_to_file_id(url)
 }
 
 pub(crate) fn file_position(
-    world: &WorldSnapshot,
+    world: &GlobalStateSnapshot,
     tdpp: lsp_types::TextDocumentPositionParams,
 ) -> Result<FilePosition> {
     let file_id = file_id(world, &tdpp.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let line_index = world.analysis.file_line_index(file_id)?;
     let offset = offset(&*line_index, tdpp.position);
     Ok(FilePosition { file_id, offset })
 }
 
 pub(crate) fn file_range(
-    world: &WorldSnapshot,
+    world: &GlobalStateSnapshot,
     text_document_identifier: lsp_types::TextDocumentIdentifier,
     range: lsp_types::Range,
 ) -> Result<FileRange> {
     let file_id = file_id(world, &text_document_identifier.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let line_index = world.analysis.file_line_index(file_id)?;
     let range = text_range(&line_index, range);
     Ok(FileRange { file_id, range })
 }
+
+pub(crate) fn assist_kind(kind: lsp_types::CodeActionKind) -> Option<AssistKind> {
+    let assist_kind = match &kind {
+        k if k == &lsp_types::CodeActionKind::EMPTY => AssistKind::None,
+        k if k == &lsp_types::CodeActionKind::QUICKFIX => AssistKind::QuickFix,
+        k if k == &lsp_types::CodeActionKind::REFACTOR => AssistKind::Refactor,
+        k if k == &lsp_types::CodeActionKind::REFACTOR_EXTRACT => AssistKind::RefactorExtract,
+        k if k == &lsp_types::CodeActionKind::REFACTOR_INLINE => AssistKind::RefactorInline,
+        k if k == &lsp_types::CodeActionKind::REFACTOR_REWRITE => AssistKind::RefactorRewrite,
+        _ => return None,
+    };
+
+    Some(assist_kind)
+}
diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
new file mode 100644
index 000000000..94973b90a
--- /dev/null
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -0,0 +1,292 @@
+//! The context or environment in which the language server functions. In our
+//! server implementation this is know as the `WorldState`.
+//!
+//! Each tick provides an immutable snapshot of the state as `WorldSnapshot`.
+
+use std::{sync::Arc, time::Instant};
+
+use crossbeam_channel::{unbounded, Receiver, Sender};
+use flycheck::FlycheckHandle;
+use lsp_types::Url;
+use parking_lot::RwLock;
+use ra_db::{CrateId, VfsPath};
+use ra_ide::{Analysis, AnalysisChange, AnalysisHost, FileId};
+use ra_project_model::{CargoWorkspace, ProcMacroClient, ProjectWorkspace, Target};
+use rustc_hash::{FxHashMap, FxHashSet};
+
+use crate::{
+    config::Config,
+    diagnostics::{CheckFixes, DiagnosticCollection},
+    from_proto,
+    line_endings::LineEndings,
+    main_loop::Task,
+    reload::SourceRootConfig,
+    request_metrics::{LatestRequests, RequestMetrics},
+    thread_pool::TaskPool,
+    to_proto::url_from_abs_path,
+    Result,
+};
+use ra_prof::profile;
+
+#[derive(Eq, PartialEq, Copy, Clone)]
+pub(crate) enum Status {
+    Loading,
+    Ready,
+    Invalid,
+    NeedsReload,
+}
+
+impl Default for Status {
+    fn default() -> Self {
+        Status::Loading
+    }
+}
+
+// Enforces drop order
+pub(crate) struct Handle<H, C> {
+    pub(crate) handle: H,
+    pub(crate) receiver: C,
+}
+
+pub(crate) type ReqHandler = fn(&mut GlobalState, lsp_server::Response);
+pub(crate) type ReqQueue = lsp_server::ReqQueue<(String, Instant), ReqHandler>;
+
+/// `GlobalState` is the primary mutable state of the language server
+///
+/// The most interesting components are `vfs`, which stores a consistent
+/// snapshot of the file systems, and `analysis_host`, which stores our
+/// incremental salsa database.
+///
+/// Note that this struct has more than on impl in various modules!
+pub(crate) struct GlobalState {
+    sender: Sender<lsp_server::Message>,
+    req_queue: ReqQueue,
+    pub(crate) task_pool: Handle<TaskPool<Task>, Receiver<Task>>,
+    pub(crate) loader: Handle<Box<dyn vfs::loader::Handle>, Receiver<vfs::loader::Message>>,
+    pub(crate) flycheck: Option<FlycheckHandle>,
+    pub(crate) flycheck_sender: Sender<flycheck::Message>,
+    pub(crate) flycheck_receiver: Receiver<flycheck::Message>,
+    pub(crate) config: Config,
+    pub(crate) analysis_host: AnalysisHost,
+    pub(crate) diagnostics: DiagnosticCollection,
+    pub(crate) mem_docs: FxHashSet<VfsPath>,
+    pub(crate) vfs: Arc<RwLock<(vfs::Vfs, FxHashMap<FileId, LineEndings>)>>,
+    pub(crate) status: Status,
+    pub(crate) source_root_config: SourceRootConfig,
+    pub(crate) proc_macro_client: ProcMacroClient,
+    pub(crate) workspaces: Arc<Vec<ProjectWorkspace>>,
+    latest_requests: Arc<RwLock<LatestRequests>>,
+}
+
+/// An immutable snapshot of the world's state at a point in time.
+pub(crate) struct GlobalStateSnapshot {
+    pub(crate) config: Config,
+    pub(crate) analysis: Analysis,
+    pub(crate) check_fixes: CheckFixes,
+    pub(crate) latest_requests: Arc<RwLock<LatestRequests>>,
+    vfs: Arc<RwLock<(vfs::Vfs, FxHashMap<FileId, LineEndings>)>>,
+    pub(crate) workspaces: Arc<Vec<ProjectWorkspace>>,
+}
+
+impl GlobalState {
+    pub(crate) fn new(sender: Sender<lsp_server::Message>, config: Config) -> GlobalState {
+        let loader = {
+            let (sender, receiver) = unbounded::<vfs::loader::Message>();
+            let handle: vfs_notify::NotifyHandle =
+                vfs::loader::Handle::spawn(Box::new(move |msg| sender.send(msg).unwrap()));
+            let handle = Box::new(handle) as Box<dyn vfs::loader::Handle>;
+            Handle { handle, receiver }
+        };
+
+        let task_pool = {
+            let (sender, receiver) = unbounded();
+            let handle = TaskPool::new(sender);
+            Handle { handle, receiver }
+        };
+
+        let analysis_host = AnalysisHost::new(config.lru_capacity);
+        let (flycheck_sender, flycheck_receiver) = unbounded();
+        GlobalState {
+            sender,
+            req_queue: ReqQueue::default(),
+            task_pool,
+            loader,
+            flycheck: None,
+            flycheck_sender,
+            flycheck_receiver,
+            config,
+            analysis_host,
+            diagnostics: Default::default(),
+            mem_docs: FxHashSet::default(),
+            vfs: Arc::new(RwLock::new((vfs::Vfs::default(), FxHashMap::default()))),
+            status: Status::default(),
+            source_root_config: SourceRootConfig::default(),
+            proc_macro_client: ProcMacroClient::dummy(),
+            workspaces: Arc::new(Vec::new()),
+            latest_requests: Default::default(),
+        }
+    }
+
+    pub(crate) fn process_changes(&mut self) -> bool {
+        let _p = profile("GlobalState::process_changes");
+        let mut fs_changes = Vec::new();
+        let mut has_fs_changes = false;
+
+        let change = {
+            let mut change = AnalysisChange::new();
+            let (vfs, line_endings_map) = &mut *self.vfs.write();
+            let changed_files = vfs.take_changes();
+            if changed_files.is_empty() {
+                return false;
+            }
+
+            for file in changed_files {
+                if file.is_created_or_deleted() {
+                    if let Some(path) = vfs.file_path(file.file_id).as_path() {
+                        fs_changes.push((path.to_path_buf(), file.change_kind));
+                        has_fs_changes = true;
+                    }
+                }
+
+                let text = if file.exists() {
+                    let bytes = vfs.file_contents(file.file_id).to_vec();
+                    match String::from_utf8(bytes).ok() {
+                        Some(text) => {
+                            let (text, line_endings) = LineEndings::normalize(text);
+                            line_endings_map.insert(file.file_id, line_endings);
+                            Some(Arc::new(text))
+                        }
+                        None => None,
+                    }
+                } else {
+                    None
+                };
+                change.change_file(file.file_id, text);
+            }
+            if has_fs_changes {
+                let roots = self.source_root_config.partition(&vfs);
+                change.set_roots(roots);
+            }
+            change
+        };
+
+        self.analysis_host.apply_change(change);
+        self.maybe_refresh(&fs_changes);
+        true
+    }
+
+    pub(crate) fn snapshot(&self) -> GlobalStateSnapshot {
+        GlobalStateSnapshot {
+            config: self.config.clone(),
+            workspaces: Arc::clone(&self.workspaces),
+            analysis: self.analysis_host.analysis(),
+            vfs: Arc::clone(&self.vfs),
+            latest_requests: Arc::clone(&self.latest_requests),
+            check_fixes: Arc::clone(&self.diagnostics.check_fixes),
+        }
+    }
+
+    pub(crate) fn send_request<R: lsp_types::request::Request>(
+        &mut self,
+        params: R::Params,
+        handler: ReqHandler,
+    ) {
+        let request = self.req_queue.outgoing.register(R::METHOD.to_string(), params, handler);
+        self.send(request.into());
+    }
+    pub(crate) fn complete_request(&mut self, response: lsp_server::Response) {
+        let handler = self.req_queue.outgoing.complete(response.id.clone());
+        handler(self, response)
+    }
+
+    pub(crate) fn send_notification<N: lsp_types::notification::Notification>(
+        &mut self,
+        params: N::Params,
+    ) {
+        let not = lsp_server::Notification::new(N::METHOD.to_string(), params);
+        self.send(not.into());
+    }
+
+    pub(crate) fn register_request(
+        &mut self,
+        request: &lsp_server::Request,
+        request_received: Instant,
+    ) {
+        self.req_queue
+            .incoming
+            .register(request.id.clone(), (request.method.clone(), request_received));
+    }
+    pub(crate) fn respond(&mut self, response: lsp_server::Response) {
+        if let Some((method, start)) = self.req_queue.incoming.complete(response.id.clone()) {
+            let duration = start.elapsed();
+            log::info!("handled req#{} in {:?}", response.id, duration);
+            let metrics = RequestMetrics { id: response.id.clone(), method, duration };
+            self.latest_requests.write().record(metrics);
+            self.send(response.into());
+        }
+    }
+    pub(crate) fn cancel(&mut self, request_id: lsp_server::RequestId) {
+        if let Some(response) = self.req_queue.incoming.cancel(request_id) {
+            self.send(response.into());
+        }
+    }
+
+    fn send(&mut self, message: lsp_server::Message) {
+        self.sender.send(message).unwrap()
+    }
+}
+
+impl Drop for GlobalState {
+    fn drop(&mut self) {
+        self.analysis_host.request_cancellation()
+    }
+}
+
+impl GlobalStateSnapshot {
+    pub(crate) fn url_to_file_id(&self, url: &Url) -> Result<FileId> {
+        url_to_file_id(&self.vfs.read().0, url)
+    }
+
+    pub(crate) fn file_id_to_url(&self, id: FileId) -> Url {
+        file_id_to_url(&self.vfs.read().0, id)
+    }
+
+    pub(crate) fn file_line_endings(&self, id: FileId) -> LineEndings {
+        self.vfs.read().1[&id]
+    }
+
+    pub(crate) fn anchored_path(&self, file_id: FileId, path: &str) -> Url {
+        let mut base = self.vfs.read().0.file_path(file_id);
+        base.pop();
+        let path = base.join(path).unwrap();
+        let path = path.as_path().unwrap();
+        url_from_abs_path(&path)
+    }
+
+    pub(crate) fn cargo_target_for_crate_root(
+        &self,
+        crate_id: CrateId,
+    ) -> Option<(&CargoWorkspace, Target)> {
+        let file_id = self.analysis.crate_root(crate_id).ok()?;
+        let path = self.vfs.read().0.file_path(file_id);
+        let path = path.as_path()?;
+        self.workspaces.iter().find_map(|ws| match ws {
+            ProjectWorkspace::Cargo { cargo, .. } => {
+                cargo.target_by_root(&path).map(|it| (cargo, it))
+            }
+            ProjectWorkspace::Json { .. } => None,
+        })
+    }
+}
+
+pub(crate) fn file_id_to_url(vfs: &vfs::Vfs, id: FileId) -> Url {
+    let path = vfs.file_path(id);
+    let path = path.as_path().unwrap();
+    url_from_abs_path(&path)
+}
+
+pub(crate) fn url_to_file_id(vfs: &vfs::Vfs, url: &Url) -> Result<FileId> {
+    let path = from_proto::vfs_path(url)?;
+    let res = vfs.file_id(&path).ok_or_else(|| format!("file not found: {}", path))?;
+    Ok(res)
+}
diff --git a/crates/rust-analyzer/src/main_loop/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 1f910ff82..d28c700f1 100644
--- a/crates/rust-analyzer/src/main_loop/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -11,41 +11,50 @@ use lsp_server::ErrorCode;
 use lsp_types::{
     CallHierarchyIncomingCall, CallHierarchyIncomingCallsParams, CallHierarchyItem,
     CallHierarchyOutgoingCall, CallHierarchyOutgoingCallsParams, CallHierarchyPrepareParams,
-    CodeLens, Command, CompletionItem, Diagnostic, DocumentFormattingParams, DocumentHighlight,
-    DocumentSymbol, FoldingRange, FoldingRangeParams, Hover, HoverContents, Location,
-    MarkupContent, MarkupKind, Position, PrepareRenameResponse, Range, RenameParams,
-    SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
-    SemanticTokensResult, SymbolInformation, TextDocumentIdentifier, Url, WorkspaceEdit,
+    CodeActionKind, CodeLens, Command, CompletionItem, Diagnostic, DocumentFormattingParams,
+    DocumentHighlight, DocumentSymbol, FoldingRange, FoldingRangeParams, HoverContents, Location,
+    Position, PrepareRenameResponse, Range, RenameParams, SemanticTokensParams,
+    SemanticTokensRangeParams, SemanticTokensRangeResult, SemanticTokensResult, SymbolInformation,
+    TextDocumentIdentifier, Url, WorkspaceEdit,
 };
-use ra_cfg::CfgExpr;
 use ra_ide::{
-    FileId, FilePosition, FileRange, Query, RangeInfo, Runnable, RunnableKind, SearchScope,
-    TextEdit,
+    FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, NavigationTarget, Query,
+    RangeInfo, Runnable, RunnableKind, SearchScope, TextEdit,
 };
 use ra_prof::profile;
 use ra_project_model::TargetKind;
-use ra_syntax::{AstNode, SmolStr, SyntaxKind, TextRange, TextSize};
-use rustc_hash::FxHashMap;
+use ra_syntax::{algo, ast, AstNode, SyntaxKind, TextRange, TextSize};
 use serde::{Deserialize, Serialize};
 use serde_json::to_value;
-use stdx::format_to;
+use stdx::{format_to, split_delim};
 
 use crate::{
     cargo_target_spec::CargoTargetSpec,
     config::RustfmtConfig,
-    diagnostics::DiagnosticTask,
     from_json, from_proto,
+    global_state::{GlobalState, GlobalStateSnapshot},
     lsp_ext::{self, InlayHint, InlayHintsParams},
-    to_proto,
-    world::WorldSnapshot,
-    LspError, Result,
+    to_proto, LspError, Result,
 };
 
-pub fn handle_analyzer_status(world: WorldSnapshot, _: ()) -> Result<String> {
+pub(crate) fn handle_analyzer_status(snap: GlobalStateSnapshot, _: ()) -> Result<String> {
     let _p = profile("handle_analyzer_status");
-    let mut buf = world.status();
+
+    let mut buf = String::new();
+    if snap.workspaces.is_empty() {
+        buf.push_str("no workspaces\n")
+    } else {
+        buf.push_str("workspaces:\n");
+        for w in snap.workspaces.iter() {
+            format_to!(buf, "{} packages loaded\n", w.n_packages());
+        }
+    }
+    buf.push_str("\nanalysis:\n");
+    buf.push_str(
+        &snap.analysis.status().unwrap_or_else(|_| "Analysis retrieval was cancelled".to_owned()),
+    );
     format_to!(buf, "\n\nrequests:\n");
-    let requests = world.latest_requests.read();
+    let requests = snap.latest_requests.read();
     for (is_last, r) in requests.iter() {
         let mark = if is_last { "*" } else { " " };
         format_to!(buf, "{}{:4} {:<36}{}ms\n", mark, r.id, r.method, r.duration.as_millis());
@@ -53,38 +62,49 @@ pub fn handle_analyzer_status(world: WorldSnapshot, _: ()) -> Result<String> {
     Ok(buf)
 }
 
-pub fn handle_syntax_tree(
-    world: WorldSnapshot,
+pub(crate) fn handle_memory_usage(state: &mut GlobalState, _: ()) -> Result<String> {
+    let _p = profile("handle_memory_usage");
+    let mem = state.analysis_host.per_query_memory_usage();
+
+    let mut out = String::new();
+    for (name, bytes) in mem {
+        format_to!(out, "{:>8} {}\n", bytes, name);
+    }
+    Ok(out)
+}
+
+pub(crate) fn handle_syntax_tree(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::SyntaxTreeParams,
 ) -> Result<String> {
     let _p = profile("handle_syntax_tree");
-    let id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(id)?;
+    let id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(id)?;
     let text_range = params.range.map(|r| from_proto::text_range(&line_index, r));
-    let res = world.analysis().syntax_tree(id, text_range)?;
+    let res = snap.analysis.syntax_tree(id, text_range)?;
     Ok(res)
 }
 
-pub fn handle_expand_macro(
-    world: WorldSnapshot,
+pub(crate) fn handle_expand_macro(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::ExpandMacroParams,
 ) -> Result<Option<lsp_ext::ExpandedMacro>> {
     let _p = profile("handle_expand_macro");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
     let offset = from_proto::offset(&line_index, params.position);
 
-    let res = world.analysis().expand_macro(FilePosition { file_id, offset })?;
+    let res = snap.analysis.expand_macro(FilePosition { file_id, offset })?;
     Ok(res.map(|it| lsp_ext::ExpandedMacro { name: it.name, expansion: it.expansion }))
 }
 
-pub fn handle_selection_range(
-    world: WorldSnapshot,
+pub(crate) fn handle_selection_range(
+    snap: GlobalStateSnapshot,
     params: lsp_types::SelectionRangeParams,
 ) -> Result<Option<Vec<lsp_types::SelectionRange>>> {
     let _p = profile("handle_selection_range");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
     let res: Result<Vec<lsp_types::SelectionRange>> = params
         .positions
         .into_iter()
@@ -96,7 +116,7 @@ pub fn handle_selection_range(
                 loop {
                     ranges.push(range);
                     let frange = FileRange { file_id, range };
-                    let next = world.analysis().extend_selection(frange)?;
+                    let next = snap.analysis.extend_selection(frange)?;
                     if next == range {
                         break;
                     } else {
@@ -121,19 +141,19 @@ pub fn handle_selection_range(
     Ok(Some(res?))
 }
 
-pub fn handle_matching_brace(
-    world: WorldSnapshot,
+pub(crate) fn handle_matching_brace(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::MatchingBraceParams,
 ) -> Result<Vec<Position>> {
     let _p = profile("handle_matching_brace");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
     let res = params
         .positions
         .into_iter()
         .map(|position| {
             let offset = from_proto::offset(&line_index, position);
-            let offset = match world.analysis().matching_brace(FilePosition { file_id, offset }) {
+            let offset = match snap.analysis.matching_brace(FilePosition { file_id, offset }) {
                 Ok(Some(matching_brace_offset)) => matching_brace_offset,
                 Err(_) | Ok(None) => offset,
             };
@@ -143,18 +163,18 @@ pub fn handle_matching_brace(
     Ok(res)
 }
 
-pub fn handle_join_lines(
-    world: WorldSnapshot,
+pub(crate) fn handle_join_lines(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::JoinLinesParams,
 ) -> Result<Vec<lsp_types::TextEdit>> {
     let _p = profile("handle_join_lines");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let line_endings = world.file_line_endings(file_id);
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let line_endings = snap.file_line_endings(file_id);
     let mut res = TextEdit::default();
     for range in params.ranges {
         let range = from_proto::text_range(&line_index, range);
-        let edit = world.analysis().join_lines(FileRange { file_id, range })?;
+        let edit = snap.analysis.join_lines(FileRange { file_id, range })?;
         match res.union(edit) {
             Ok(()) => (),
             Err(_edit) => {
@@ -166,38 +186,38 @@ pub fn handle_join_lines(
     Ok(res)
 }
 
-pub fn handle_on_enter(
-    world: WorldSnapshot,
+pub(crate) fn handle_on_enter(
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<Vec<lsp_ext::SnippetTextEdit>>> {
     let _p = profile("handle_on_enter");
-    let position = from_proto::file_position(&world, params)?;
-    let edit = match world.analysis().on_enter(position)? {
+    let position = from_proto::file_position(&snap, params)?;
+    let edit = match snap.analysis.on_enter(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
     let edit = to_proto::snippet_text_edit_vec(&line_index, line_endings, true, edit);
     Ok(Some(edit))
 }
 
 // Don't forget to add new trigger characters to `ServerCapabilities` in `caps.rs`.
-pub fn handle_on_type_formatting(
-    world: WorldSnapshot,
+pub(crate) fn handle_on_type_formatting(
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentOnTypeFormattingParams,
 ) -> Result<Option<Vec<lsp_types::TextEdit>>> {
     let _p = profile("handle_on_type_formatting");
-    let mut position = from_proto::file_position(&world, params.text_document_position)?;
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let mut position = from_proto::file_position(&snap, params.text_document_position)?;
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
 
     // in `ra_ide`, the `on_type` invariant is that
     // `text.char_at(position) == typed_char`.
     position.offset -= TextSize::of('.');
     let char_typed = params.ch.chars().next().unwrap_or('\0');
     assert!({
-        let text = world.analysis().file_text(position.file_id)?;
+        let text = snap.analysis.file_text(position.file_id)?;
         text[usize::from(position.offset)..].starts_with(char_typed)
     });
 
@@ -209,7 +229,7 @@ pub fn handle_on_type_formatting(
         return Ok(None);
     }
 
-    let edit = world.analysis().on_char_typed(position, char_typed)?;
+    let edit = snap.analysis.on_char_typed(position, char_typed)?;
     let mut edit = match edit {
         Some(it) => it,
         None => return Ok(None),
@@ -222,17 +242,17 @@ pub fn handle_on_type_formatting(
     Ok(Some(change))
 }
 
-pub fn handle_document_symbol(
-    world: WorldSnapshot,
+pub(crate) fn handle_document_symbol(
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentSymbolParams,
 ) -> Result<Option<lsp_types::DocumentSymbolResponse>> {
     let _p = profile("handle_document_symbol");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
 
     let mut parents: Vec<(DocumentSymbol, Option<usize>)> = Vec::new();
 
-    for symbol in world.analysis().file_structure(file_id)? {
+    for symbol in snap.analysis.file_structure(file_id)? {
         let doc_symbol = DocumentSymbol {
             name: symbol.label,
             detail: symbol.detail,
@@ -258,10 +278,10 @@ pub fn handle_document_symbol(
         }
     }
 
-    let res = if world.config.client_caps.hierarchical_symbols {
+    let res = if snap.config.client_caps.hierarchical_symbols {
         document_symbols.into()
     } else {
-        let url = to_proto::url(&world, file_id)?;
+        let url = to_proto::url(&snap, file_id);
         let mut symbol_information = Vec::<SymbolInformation>::new();
         for symbol in document_symbols {
             flatten_document_symbol(&symbol, None, &url, &mut symbol_information);
@@ -290,8 +310,8 @@ pub fn handle_document_symbol(
     }
 }
 
-pub fn handle_workspace_symbol(
-    world: WorldSnapshot,
+pub(crate) fn handle_workspace_symbol(
+    snap: GlobalStateSnapshot,
     params: lsp_types::WorkspaceSymbolParams,
 ) -> Result<Option<Vec<SymbolInformation>>> {
     let _p = profile("handle_workspace_symbol");
@@ -309,23 +329,24 @@ pub fn handle_workspace_symbol(
         q.limit(128);
         q
     };
-    let mut res = exec_query(&world, query)?;
+    let mut res = exec_query(&snap, query)?;
     if res.is_empty() && !all_symbols {
         let mut query = Query::new(params.query);
         query.limit(128);
-        res = exec_query(&world, query)?;
+        res = exec_query(&snap, query)?;
     }
 
     return Ok(Some(res));
 
-    fn exec_query(world: &WorldSnapshot, query: Query) -> Result<Vec<SymbolInformation>> {
+    fn exec_query(snap: &GlobalStateSnapshot, query: Query) -> Result<Vec<SymbolInformation>> {
         let mut res = Vec::new();
-        for nav in world.analysis().symbol_search(query)? {
+        for nav in snap.analysis.symbol_search(query)? {
+            let container_name = nav.container_name().map(|v| v.to_string());
             let info = SymbolInformation {
                 name: nav.name().to_string(),
                 kind: to_proto::symbol_kind(nav.kind()),
-                location: to_proto::location(world, nav.file_range())?,
-                container_name: nav.container_name().map(|v| v.to_string()),
+                location: to_proto::location_from_nav(snap, nav)?,
+                container_name,
                 deprecated: None,
             };
             res.push(info);
@@ -334,89 +355,98 @@ pub fn handle_workspace_symbol(
     }
 }
 
-pub fn handle_goto_definition(
-    world: WorldSnapshot,
+pub(crate) fn handle_goto_definition(
+    snap: GlobalStateSnapshot,
     params: lsp_types::GotoDefinitionParams,
 ) -> Result<Option<lsp_types::GotoDefinitionResponse>> {
     let _p = profile("handle_goto_definition");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_definition(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis.goto_definition(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
-pub fn handle_goto_implementation(
-    world: WorldSnapshot,
+pub(crate) fn handle_goto_implementation(
+    snap: GlobalStateSnapshot,
     params: lsp_types::request::GotoImplementationParams,
 ) -> Result<Option<lsp_types::request::GotoImplementationResponse>> {
     let _p = profile("handle_goto_implementation");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_implementation(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis.goto_implementation(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
-pub fn handle_goto_type_definition(
-    world: WorldSnapshot,
+pub(crate) fn handle_goto_type_definition(
+    snap: GlobalStateSnapshot,
     params: lsp_types::request::GotoTypeDefinitionParams,
 ) -> Result<Option<lsp_types::request::GotoTypeDefinitionResponse>> {
     let _p = profile("handle_goto_type_definition");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_type_definition(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis.goto_type_definition(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
-pub fn handle_parent_module(
-    world: WorldSnapshot,
+pub(crate) fn handle_parent_module(
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<lsp_types::GotoDefinitionResponse>> {
     let _p = profile("handle_parent_module");
-    let position = from_proto::file_position(&world, params)?;
-    let navs = world.analysis().parent_module(position)?;
-    let res = to_proto::goto_definition_response(&world, None, navs)?;
+    let position = from_proto::file_position(&snap, params)?;
+    let navs = snap.analysis.parent_module(position)?;
+    let res = to_proto::goto_definition_response(&snap, None, navs)?;
     Ok(Some(res))
 }
 
-pub fn handle_runnables(
-    world: WorldSnapshot,
+pub(crate) fn handle_runnables(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::RunnablesParams,
 ) -> Result<Vec<lsp_ext::Runnable>> {
     let _p = profile("handle_runnables");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
     let offset = params.position.map(|it| from_proto::offset(&line_index, it));
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id)?;
+
+    let expect_test = match offset {
+        Some(offset) => {
+            let source_file = snap.analysis.parse(file_id)?;
+            algo::find_node_at_offset::<ast::MacroCall>(source_file.syntax(), offset)
+                .and_then(|it| it.path()?.segment()?.name_ref())
+                .map_or(false, |it| it.text() == "expect" || it.text() == "expect_file")
+        }
+        None => false,
+    };
+
     let mut res = Vec::new();
-    let workspace_root = world.workspace_root_for(file_id);
-    let cargo_spec = CargoTargetSpec::for_file(&world, file_id)?;
-    for runnable in world.analysis().runnables(file_id)? {
+    for runnable in snap.analysis.runnables(file_id)? {
         if let Some(offset) = offset {
-            if !runnable.range.contains_inclusive(offset) {
+            if !runnable.nav.full_range().contains_inclusive(offset) {
                 continue;
             }
         }
-        // Do not suggest binary run on other target than binary
-        if let RunnableKind::Bin = runnable.kind {
-            if let Some(spec) = &cargo_spec {
-                match spec.target_kind {
-                    TargetKind::Bin => {}
-                    _ => continue,
-                }
-            }
+        if should_skip_target(&runnable, cargo_spec.as_ref()) {
+            continue;
+        }
+        let mut runnable = to_proto::runnable(&snap, file_id, runnable)?;
+        if expect_test {
+            runnable.label = format!("{} + expect", runnable.label);
+            runnable.args.expect_test = Some(true);
         }
-        res.push(to_lsp_runnable(&world, file_id, runnable)?);
+        res.push(runnable);
     }
 
     // Add `cargo check` and `cargo test` for the whole package
@@ -424,42 +454,50 @@ pub fn handle_runnables(
         Some(spec) => {
             for &cmd in ["check", "test"].iter() {
                 res.push(lsp_ext::Runnable {
-                    range: Default::default(),
                     label: format!("cargo {} -p {}", cmd, spec.package),
-                    bin: "cargo".to_string(),
-                    args: vec![cmd.to_string(), "--package".to_string(), spec.package.clone()],
-                    extra_args: Vec::new(),
-                    env: FxHashMap::default(),
-                    cwd: workspace_root.map(|root| root.to_owned()),
+                    location: None,
+                    kind: lsp_ext::RunnableKind::Cargo,
+                    args: lsp_ext::CargoRunnable {
+                        workspace_root: Some(spec.workspace_root.clone().into()),
+                        cargo_args: vec![
+                            cmd.to_string(),
+                            "--package".to_string(),
+                            spec.package.clone(),
+                        ],
+                        executable_args: Vec::new(),
+                        expect_test: None,
+                    },
                 })
             }
         }
         None => {
             res.push(lsp_ext::Runnable {
-                range: Default::default(),
                 label: "cargo check --workspace".to_string(),
-                bin: "cargo".to_string(),
-                args: vec!["check".to_string(), "--workspace".to_string()],
-                extra_args: Vec::new(),
-                env: FxHashMap::default(),
-                cwd: workspace_root.map(|root| root.to_owned()),
+                location: None,
+                kind: lsp_ext::RunnableKind::Cargo,
+                args: lsp_ext::CargoRunnable {
+                    workspace_root: None,
+                    cargo_args: vec!["check".to_string(), "--workspace".to_string()],
+                    executable_args: Vec::new(),
+                    expect_test: None,
+                },
             });
         }
     }
     Ok(res)
 }
 
-pub fn handle_completion(
-    world: WorldSnapshot,
+pub(crate) fn handle_completion(
+    snap: GlobalStateSnapshot,
     params: lsp_types::CompletionParams,
 ) -> Result<Option<lsp_types::CompletionResponse>> {
     let _p = profile("handle_completion");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
     let completion_triggered_after_single_colon = {
         let mut res = false;
         if let Some(ctx) = params.context {
             if ctx.trigger_character.unwrap_or_default() == ":" {
-                let source_file = world.analysis().parse(position.file_id)?;
+                let source_file = snap.analysis.parse(position.file_id)?;
                 let syntax = source_file.syntax();
                 let text = syntax.text();
                 if let Some(next_char) = text.char_at(position.offset) {
@@ -477,12 +515,12 @@ pub fn handle_completion(
         return Ok(None);
     }
 
-    let items = match world.analysis().completions(&world.config.completion, position)? {
+    let items = match snap.analysis.completions(&snap.config.completion, position)? {
         None => return Ok(None),
         Some(items) => items,
     };
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
     let items: Vec<CompletionItem> = items
         .into_iter()
         .map(|item| to_proto::completion_item(&line_index, line_endings, item))
@@ -491,16 +529,16 @@ pub fn handle_completion(
     Ok(Some(items.into()))
 }
 
-pub fn handle_folding_range(
-    world: WorldSnapshot,
+pub(crate) fn handle_folding_range(
+    snap: GlobalStateSnapshot,
     params: FoldingRangeParams,
 ) -> Result<Option<Vec<FoldingRange>>> {
     let _p = profile("handle_folding_range");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let folds = world.analysis().folding_ranges(file_id)?;
-    let text = world.analysis().file_text(file_id)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let line_folding_only = world.config.client_caps.line_folding_only;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let folds = snap.analysis.folding_ranges(file_id)?;
+    let text = snap.analysis.file_text(file_id)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let line_folding_only = snap.config.client_caps.line_folding_only;
     let res = folds
         .into_iter()
         .map(|it| to_proto::folding_range(&*text, &line_index, line_folding_only, it))
@@ -508,17 +546,17 @@ pub fn handle_folding_range(
     Ok(Some(res))
 }
 
-pub fn handle_signature_help(
-    world: WorldSnapshot,
+pub(crate) fn handle_signature_help(
+    snap: GlobalStateSnapshot,
     params: lsp_types::SignatureHelpParams,
 ) -> Result<Option<lsp_types::SignatureHelp>> {
     let _p = profile("handle_signature_help");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let call_info = match world.analysis().call_info(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let call_info = match snap.analysis.call_info(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
-    let concise = !world.config.call_info_full;
+    let concise = !snap.config.call_info_full;
     let mut active_parameter = call_info.active_parameter.map(|it| it as i64);
     if concise && call_info.signature.has_self_param {
         active_parameter = active_parameter.map(|it| it.saturating_sub(1));
@@ -532,46 +570,53 @@ pub fn handle_signature_help(
     }))
 }
 
-pub fn handle_hover(world: WorldSnapshot, params: lsp_types::HoverParams) -> Result<Option<Hover>> {
+pub(crate) fn handle_hover(
+    snap: GlobalStateSnapshot,
+    params: lsp_types::HoverParams,
+) -> Result<Option<lsp_ext::Hover>> {
     let _p = profile("handle_hover");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let info = match world.analysis().hover(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let info = match snap.analysis.hover(position)? {
         None => return Ok(None),
         Some(info) => info,
     };
-    let line_index = world.analysis.file_line_index(position.file_id)?;
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, info.range);
-    let res = Hover {
-        contents: HoverContents::Markup(MarkupContent {
-            kind: MarkupKind::Markdown,
-            value: crate::markdown::format_docs(&info.info.to_markup()),
-        }),
-        range: Some(range),
+    let hover = lsp_ext::Hover {
+        hover: lsp_types::Hover {
+            contents: HoverContents::Markup(to_proto::markup_content(info.info.markup)),
+            range: Some(range),
+        },
+        actions: prepare_hover_actions(&snap, position.file_id, &info.info.actions),
     };
-    Ok(Some(res))
+
+    Ok(Some(hover))
 }
 
-pub fn handle_prepare_rename(
-    world: WorldSnapshot,
+pub(crate) fn handle_prepare_rename(
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<PrepareRenameResponse>> {
     let _p = profile("handle_prepare_rename");
-    let position = from_proto::file_position(&world, params)?;
+    let position = from_proto::file_position(&snap, params)?;
 
-    let optional_change = world.analysis().rename(position, "dummy")?;
+    let optional_change = snap.analysis.rename(position, "dummy")?;
     let range = match optional_change {
         None => return Ok(None),
         Some(it) => it.range,
     };
 
-    let line_index = world.analysis().file_line_index(position.file_id)?;
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, range);
     Ok(Some(PrepareRenameResponse::Range(range)))
 }
 
-pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Option<WorkspaceEdit>> {
+pub(crate) fn handle_rename(
+    snap: GlobalStateSnapshot,
+    params: RenameParams,
+) -> Result<Option<WorkspaceEdit>> {
     let _p = profile("handle_rename");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
 
     if params.new_name.is_empty() {
         return Err(LspError::new(
@@ -581,61 +626,61 @@ pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Optio
         .into());
     }
 
-    let optional_change = world.analysis().rename(position, &*params.new_name)?;
+    let optional_change = snap.analysis.rename(position, &*params.new_name)?;
     let source_change = match optional_change {
         None => return Ok(None),
         Some(it) => it.info,
     };
-    let workspace_edit = to_proto::workspace_edit(&world, source_change)?;
+    let workspace_edit = to_proto::workspace_edit(&snap, source_change)?;
     Ok(Some(workspace_edit))
 }
 
-pub fn handle_references(
-    world: WorldSnapshot,
+pub(crate) fn handle_references(
+    snap: GlobalStateSnapshot,
     params: lsp_types::ReferenceParams,
 ) -> Result<Option<Vec<Location>>> {
     let _p = profile("handle_references");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
 
-    let refs = match world.analysis().find_all_refs(position, None)? {
+    let refs = match snap.analysis.find_all_refs(position, None)? {
         None => return Ok(None),
         Some(refs) => refs,
     };
 
     let locations = if params.context.include_declaration {
         refs.into_iter()
-            .filter_map(|reference| to_proto::location(&world, reference.file_range).ok())
+            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
             .collect()
     } else {
         // Only iterate over the references if include_declaration was false
         refs.references()
             .iter()
-            .filter_map(|reference| to_proto::location(&world, reference.file_range).ok())
+            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
             .collect()
     };
 
     Ok(Some(locations))
 }
 
-pub fn handle_formatting(
-    world: WorldSnapshot,
+pub(crate) fn handle_formatting(
+    snap: GlobalStateSnapshot,
     params: DocumentFormattingParams,
 ) -> Result<Option<Vec<lsp_types::TextEdit>>> {
     let _p = profile("handle_formatting");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let file = world.analysis().file_text(file_id)?;
-    let crate_ids = world.analysis().crate_for(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let file = snap.analysis.file_text(file_id)?;
+    let crate_ids = snap.analysis.crate_for(file_id)?;
 
-    let file_line_index = world.analysis().file_line_index(file_id)?;
+    let file_line_index = snap.analysis.file_line_index(file_id)?;
     let end_position = to_proto::position(&file_line_index, TextSize::of(file.as_str()));
 
-    let mut rustfmt = match &world.config.rustfmt {
+    let mut rustfmt = match &snap.config.rustfmt {
         RustfmtConfig::Rustfmt { extra_args } => {
-            let mut cmd = process::Command::new("rustfmt");
+            let mut cmd = process::Command::new(ra_toolchain::rustfmt());
             cmd.args(extra_args);
             if let Some(&crate_id) = crate_ids.first() {
                 // Assume all crates are in the same edition
-                let edition = world.analysis().crate_edition(crate_id)?;
+                let edition = snap.analysis.crate_edition(crate_id)?;
                 cmd.arg("--edition");
                 cmd.arg(edition.to_string());
             }
@@ -693,141 +738,180 @@ pub fn handle_formatting(
     }]))
 }
 
-pub fn handle_code_action(
-    world: WorldSnapshot,
-    params: lsp_types::CodeActionParams,
-) -> Result<Option<Vec<lsp_ext::CodeAction>>> {
-    let _p = profile("handle_code_action");
-    // We intentionally don't support command-based actions, as those either
-    // requires custom client-code anyway, or requires server-initiated edits.
-    // Server initiated edits break causality, so we avoid those as well.
-    if !world.config.client_caps.code_action_literals {
-        return Ok(None);
-    }
-
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+fn handle_fixes(
+    snap: &GlobalStateSnapshot,
+    params: &lsp_types::CodeActionParams,
+    res: &mut Vec<lsp_ext::CodeAction>,
+) -> Result<()> {
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
     let range = from_proto::text_range(&line_index, params.range);
-    let frange = FileRange { file_id, range };
 
-    let diagnostics = world.analysis().diagnostics(file_id)?;
-    let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
+    match &params.context.only {
+        Some(v) => {
+            if !v.iter().any(|it| {
+                it == &lsp_types::CodeActionKind::EMPTY
+                    || it == &lsp_types::CodeActionKind::QUICKFIX
+            }) {
+                return Ok(());
+            }
+        }
+        None => {}
+    };
+
+    let diagnostics = snap.analysis.diagnostics(file_id)?;
 
     let fixes_from_diagnostics = diagnostics
         .into_iter()
         .filter_map(|d| Some((d.range, d.fix?)))
         .filter(|(diag_range, _fix)| diag_range.intersect(range).is_some())
         .map(|(_range, fix)| fix);
-
     for fix in fixes_from_diagnostics {
         let title = fix.label;
-        let edit = to_proto::snippet_workspace_edit(&world, fix.source_change)?;
-        let action =
-            lsp_ext::CodeAction { title, group: None, kind: None, edit: Some(edit), command: None };
+        let edit = to_proto::snippet_workspace_edit(&snap, fix.source_change)?;
+        let action = lsp_ext::CodeAction {
+            title,
+            id: None,
+            group: None,
+            kind: Some(CodeActionKind::QUICKFIX),
+            edit: Some(edit),
+        };
         res.push(action);
     }
 
-    for fix in world.check_fixes.get(&file_id).into_iter().flatten() {
+    for fix in snap.check_fixes.get(&file_id).into_iter().flatten() {
         let fix_range = from_proto::text_range(&line_index, fix.range);
         if fix_range.intersect(range).is_none() {
             continue;
         }
         res.push(fix.action.clone());
     }
+    Ok(())
+}
+
+pub(crate) fn handle_code_action(
+    mut snap: GlobalStateSnapshot,
+    params: lsp_types::CodeActionParams,
+) -> Result<Option<Vec<lsp_ext::CodeAction>>> {
+    let _p = profile("handle_code_action");
+    // We intentionally don't support command-based actions, as those either
+    // requires custom client-code anyway, or requires server-initiated edits.
+    // Server initiated edits break causality, so we avoid those as well.
+    if !snap.config.client_caps.code_action_literals {
+        return Ok(None);
+    }
+
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let range = from_proto::text_range(&line_index, params.range);
+    let frange = FileRange { file_id, range };
+
+    snap.config.assist.allowed = params
+        .clone()
+        .context
+        .only
+        .map(|it| it.into_iter().filter_map(from_proto::assist_kind).collect());
+
+    let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
+
+    handle_fixes(&snap, &params, &mut res)?;
 
-    for assist in world.analysis().assists(&world.config.assist, frange)?.into_iter() {
-        res.push(to_proto::code_action(&world, assist)?.into());
+    if snap.config.client_caps.resolve_code_action {
+        for (index, assist) in
+            snap.analysis.unresolved_assists(&snap.config.assist, frange)?.into_iter().enumerate()
+        {
+            res.push(to_proto::unresolved_code_action(&snap, assist, index)?);
+        }
+    } else {
+        for assist in snap.analysis.resolved_assists(&snap.config.assist, frange)?.into_iter() {
+            res.push(to_proto::resolved_code_action(&snap, assist)?);
+        }
     }
+
     Ok(Some(res))
 }
 
-pub fn handle_code_lens(
-    world: WorldSnapshot,
+pub(crate) fn handle_resolve_code_action(
+    mut snap: GlobalStateSnapshot,
+    params: lsp_ext::ResolveCodeActionParams,
+) -> Result<Option<lsp_ext::SnippetWorkspaceEdit>> {
+    let _p = profile("handle_resolve_code_action");
+    let file_id = from_proto::file_id(&snap, &params.code_action_params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let range = from_proto::text_range(&line_index, params.code_action_params.range);
+    let frange = FileRange { file_id, range };
+
+    snap.config.assist.allowed = params
+        .code_action_params
+        .context
+        .only
+        .map(|it| it.into_iter().filter_map(from_proto::assist_kind).collect());
+
+    let assists = snap.analysis.resolved_assists(&snap.config.assist, frange)?;
+    let (id_string, index) = split_delim(&params.id, ':').unwrap();
+    let index = index.parse::<usize>().unwrap();
+    let assist = &assists[index];
+    assert!(assist.assist.id.0 == id_string);
+    Ok(to_proto::resolved_code_action(&snap, assist.clone())?.edit)
+}
+
+pub(crate) fn handle_code_lens(
+    snap: GlobalStateSnapshot,
     params: lsp_types::CodeLensParams,
 ) -> Result<Option<Vec<CodeLens>>> {
     let _p = profile("handle_code_lens");
     let mut lenses: Vec<CodeLens> = Default::default();
 
-    if world.config.lens.none() {
+    if snap.config.lens.none() {
         // early return before any db query!
         return Ok(Some(lenses));
     }
 
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let cargo_spec = CargoTargetSpec::for_file(&world, file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id)?;
 
-    if world.config.lens.runnable() {
+    if snap.config.lens.runnable() {
         // Gather runnables
-        for runnable in world.analysis().runnables(file_id)? {
-            let (run_title, debugee) = match &runnable.kind {
-                RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => {
-                    ("▶\u{fe0e} Run Test", true)
-                }
-                RunnableKind::DocTest { .. } => {
-                    // cargo does not support -no-run for doctests
-                    ("▶\u{fe0e} Run Doctest", false)
-                }
-                RunnableKind::Bench { .. } => {
-                    // Nothing wrong with bench debugging
-                    ("Run Bench", true)
-                }
-                RunnableKind::Bin => {
-                    // Do not suggest binary run on other target than binary
-                    match &cargo_spec {
-                        Some(spec) => match spec.target_kind {
-                            TargetKind::Bin => ("Run", true),
-                            _ => continue,
-                        },
-                        None => continue,
-                    }
-                }
-            };
+        for runnable in snap.analysis.runnables(file_id)? {
+            if should_skip_target(&runnable, cargo_spec.as_ref()) {
+                continue;
+            }
 
-            let mut r = to_lsp_runnable(&world, file_id, runnable)?;
-            if world.config.lens.run {
+            let action = runnable.action();
+            let range = to_proto::range(&line_index, runnable.nav.range());
+            let r = to_proto::runnable(&snap, file_id, runnable)?;
+            if snap.config.lens.run {
                 let lens = CodeLens {
-                    range: r.range,
-                    command: Some(Command {
-                        title: run_title.to_string(),
-                        command: "rust-analyzer.runSingle".into(),
-                        arguments: Some(vec![to_value(&r).unwrap()]),
-                    }),
+                    range,
+                    command: Some(run_single_command(&r, action.run_title)),
                     data: None,
                 };
                 lenses.push(lens);
             }
 
-            if debugee && world.config.lens.debug {
-                if r.args[0] == "run" {
-                    r.args[0] = "build".into();
-                } else {
-                    r.args.push("--no-run".into());
-                }
-                let debug_lens = CodeLens {
-                    range: r.range,
-                    command: Some(Command {
-                        title: "Debug".into(),
-                        command: "rust-analyzer.debugSingle".into(),
-                        arguments: Some(vec![to_value(r).unwrap()]),
-                    }),
-                    data: None,
-                };
+            if action.debugee && snap.config.lens.debug {
+                let debug_lens =
+                    CodeLens { range, command: Some(debug_single_command(&r)), data: None };
                 lenses.push(debug_lens);
             }
         }
     }
 
-    if world.config.lens.impementations {
+    if snap.config.lens.implementations {
         // Handle impls
         lenses.extend(
-            world
-                .analysis()
+            snap.analysis
                 .file_structure(file_id)?
                 .into_iter()
-                .filter(|it| match it.kind {
-                    SyntaxKind::TRAIT_DEF | SyntaxKind::STRUCT_DEF | SyntaxKind::ENUM_DEF => true,
-                    _ => false,
+                .filter(|it| {
+                    matches!(
+                        it.kind,
+                        SyntaxKind::TRAIT_DEF
+                            | SyntaxKind::STRUCT_DEF
+                            | SyntaxKind::ENUM_DEF
+                            | SyntaxKind::UNION_DEF
+                    )
                 })
                 .map(|it| {
                     let range = to_proto::range(&line_index, it.node_range);
@@ -857,14 +941,17 @@ enum CodeLensResolveData {
     Impls(lsp_types::request::GotoImplementationParams),
 }
 
-pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Result<CodeLens> {
+pub(crate) fn handle_code_lens_resolve(
+    snap: GlobalStateSnapshot,
+    code_lens: CodeLens,
+) -> Result<CodeLens> {
     let _p = profile("handle_code_lens_resolve");
     let data = code_lens.data.unwrap();
     let resolve = from_json::<Option<CodeLensResolveData>>("CodeLensResolveData", data)?;
     match resolve {
         Some(CodeLensResolveData::Impls(lens_params)) => {
             let locations: Vec<Location> =
-                match handle_goto_implementation(world, lens_params.clone())? {
+                match handle_goto_implementation(snap, lens_params.clone())? {
                     Some(lsp_types::GotoDefinitionResponse::Scalar(loc)) => vec![loc],
                     Some(lsp_types::GotoDefinitionResponse::Array(locs)) => locs,
                     Some(lsp_types::GotoDefinitionResponse::Link(links)) => links
@@ -874,24 +961,13 @@ pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Re
                     _ => vec![],
                 };
 
-            let title = if locations.len() == 1 {
-                "1 implementation".into()
-            } else {
-                format!("{} implementations", locations.len())
-            };
-
-            // We cannot use the 'editor.action.showReferences' command directly
-            // because that command requires vscode types which we convert in the handler
-            // on the client side.
-            let cmd = Command {
+            let title = implementation_title(locations.len());
+            let cmd = show_references_command(
                 title,
-                command: "rust-analyzer.showReferences".into(),
-                arguments: Some(vec![
-                    to_value(&lens_params.text_document_position_params.text_document.uri).unwrap(),
-                    to_value(code_lens.range.start).unwrap(),
-                    to_value(locations).unwrap(),
-                ]),
-            };
+                &lens_params.text_document_position_params.text_document.uri,
+                code_lens.range.start,
+                locations,
+            );
             Ok(CodeLens { range: code_lens.range, command: Some(cmd), data: None })
         }
         None => Ok(CodeLens {
@@ -902,16 +978,16 @@ pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Re
     }
 }
 
-pub fn handle_document_highlight(
-    world: WorldSnapshot,
+pub(crate) fn handle_document_highlight(
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentHighlightParams,
 ) -> Result<Option<Vec<DocumentHighlight>>> {
     let _p = profile("handle_document_highlight");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let line_index = world.analysis().file_line_index(position.file_id)?;
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
 
-    let refs = match world
-        .analysis()
+    let refs = match snap
+        .analysis
         .find_all_refs(position, Some(SearchScope::single_file(position.file_id)))?
     {
         None => return Ok(None),
@@ -929,21 +1005,24 @@ pub fn handle_document_highlight(
     Ok(Some(res))
 }
 
-pub fn handle_ssr(
-    world: WorldSnapshot,
+pub(crate) fn handle_ssr(
+    snap: GlobalStateSnapshot,
     params: lsp_ext::SsrParams,
 ) -> Result<lsp_types::WorkspaceEdit> {
     let _p = profile("handle_ssr");
     let source_change =
-        world.analysis().structural_search_replace(&params.query, params.parse_only)??;
-    to_proto::workspace_edit(&world, source_change)
+        snap.analysis.structural_search_replace(&params.query, params.parse_only)??;
+    to_proto::workspace_edit(&snap, source_change)
 }
 
-pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<DiagnosticTask> {
+pub(crate) fn publish_diagnostics(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+) -> Result<Vec<Diagnostic>> {
     let _p = profile("publish_diagnostics");
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let diagnostics: Vec<Diagnostic> = world
-        .analysis()
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    let diagnostics: Vec<Diagnostic> = snap
+        .analysis
         .diagnostics(file_id)?
         .into_iter()
         .map(|d| Diagnostic {
@@ -956,90 +1035,32 @@ pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<Dia
             tags: None,
         })
         .collect();
-    Ok(DiagnosticTask::SetNative(file_id, diagnostics))
-}
-
-fn to_lsp_runnable(
-    world: &WorldSnapshot,
-    file_id: FileId,
-    runnable: Runnable,
-) -> Result<lsp_ext::Runnable> {
-    let spec = CargoTargetSpec::for_file(world, file_id)?;
-    let target = spec.as_ref().map(|s| s.target.clone());
-    let mut features_needed = vec![];
-    for cfg_expr in &runnable.cfg_exprs {
-        collect_minimal_features_needed(cfg_expr, &mut features_needed);
-    }
-    let (args, extra_args) =
-        CargoTargetSpec::runnable_args(spec, &runnable.kind, &features_needed)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let label = match &runnable.kind {
-        RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
-        RunnableKind::TestMod { path } => format!("test-mod {}", path),
-        RunnableKind::Bench { test_id } => format!("bench {}", test_id),
-        RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
-        RunnableKind::Bin => {
-            target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
-        }
-    };
-    Ok(lsp_ext::Runnable {
-        range: to_proto::range(&line_index, runnable.range),
-        label,
-        bin: "cargo".to_string(),
-        args,
-        extra_args,
-        env: {
-            let mut m = FxHashMap::default();
-            m.insert("RUST_BACKTRACE".to_string(), "short".to_string());
-            m
-        },
-        cwd: world.workspace_root_for(file_id).map(|root| root.to_owned()),
-    })
+    Ok(diagnostics)
 }
 
-/// Fill minimal features needed
-fn collect_minimal_features_needed(cfg_expr: &CfgExpr, features: &mut Vec<SmolStr>) {
-    match cfg_expr {
-        CfgExpr::KeyValue { key, value } if key == "feature" => features.push(value.clone()),
-        CfgExpr::All(preds) => {
-            preds.iter().for_each(|cfg| collect_minimal_features_needed(cfg, features));
-        }
-        CfgExpr::Any(preds) => {
-            for cfg in preds {
-                let len_features = features.len();
-                collect_minimal_features_needed(cfg, features);
-                if len_features != features.len() {
-                    break;
-                }
-            }
-        }
-        _ => {}
-    }
-}
-
-pub fn handle_inlay_hints(
-    world: WorldSnapshot,
+pub(crate) fn handle_inlay_hints(
+    snap: GlobalStateSnapshot,
     params: InlayHintsParams,
 ) -> Result<Vec<InlayHint>> {
     let _p = profile("handle_inlay_hints");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let analysis = world.analysis();
-    let line_index = analysis.file_line_index(file_id)?;
-    Ok(analysis
-        .inlay_hints(file_id, &world.config.inlay_hints)?
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
+    Ok(snap
+        .analysis
+        .inlay_hints(file_id, &snap.config.inlay_hints)?
         .into_iter()
         .map(|it| to_proto::inlay_int(&line_index, it))
         .collect())
 }
 
-pub fn handle_call_hierarchy_prepare(
-    world: WorldSnapshot,
+pub(crate) fn handle_call_hierarchy_prepare(
+    snap: GlobalStateSnapshot,
     params: CallHierarchyPrepareParams,
 ) -> Result<Option<Vec<CallHierarchyItem>>> {
     let _p = profile("handle_call_hierarchy_prepare");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
 
-    let nav_info = match world.analysis().call_hierarchy(position)? {
+    let nav_info = match snap.analysis.call_hierarchy(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1048,24 +1069,24 @@ pub fn handle_call_hierarchy_prepare(
     let res = navs
         .into_iter()
         .filter(|it| it.kind() == SyntaxKind::FN_DEF)
-        .map(|it| to_proto::call_hierarchy_item(&world, it))
+        .map(|it| to_proto::call_hierarchy_item(&snap, it))
         .collect::<Result<Vec<_>>>()?;
 
     Ok(Some(res))
 }
 
-pub fn handle_call_hierarchy_incoming(
-    world: WorldSnapshot,
+pub(crate) fn handle_call_hierarchy_incoming(
+    snap: GlobalStateSnapshot,
     params: CallHierarchyIncomingCallsParams,
 ) -> Result<Option<Vec<CallHierarchyIncomingCall>>> {
     let _p = profile("handle_call_hierarchy_incoming");
     let item = params.item;
 
     let doc = TextDocumentIdentifier::new(item.uri);
-    let frange = from_proto::file_range(&world, doc, item.range)?;
+    let frange = from_proto::file_range(&snap, doc, item.selection_range)?;
     let fpos = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
 
-    let call_items = match world.analysis().incoming_calls(fpos)? {
+    let call_items = match snap.analysis.incoming_calls(fpos)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1074,8 +1095,8 @@ pub fn handle_call_hierarchy_incoming(
 
     for call_item in call_items.into_iter() {
         let file_id = call_item.target.file_id();
-        let line_index = world.analysis().file_line_index(file_id)?;
-        let item = to_proto::call_hierarchy_item(&world, call_item.target)?;
+        let line_index = snap.analysis.file_line_index(file_id)?;
+        let item = to_proto::call_hierarchy_item(&snap, call_item.target)?;
         res.push(CallHierarchyIncomingCall {
             from: item,
             from_ranges: call_item
@@ -1089,18 +1110,18 @@ pub fn handle_call_hierarchy_incoming(
     Ok(Some(res))
 }
 
-pub fn handle_call_hierarchy_outgoing(
-    world: WorldSnapshot,
+pub(crate) fn handle_call_hierarchy_outgoing(
+    snap: GlobalStateSnapshot,
     params: CallHierarchyOutgoingCallsParams,
 ) -> Result<Option<Vec<CallHierarchyOutgoingCall>>> {
     let _p = profile("handle_call_hierarchy_outgoing");
     let item = params.item;
 
     let doc = TextDocumentIdentifier::new(item.uri);
-    let frange = from_proto::file_range(&world, doc, item.range)?;
+    let frange = from_proto::file_range(&snap, doc, item.selection_range)?;
     let fpos = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
 
-    let call_items = match world.analysis().outgoing_calls(fpos)? {
+    let call_items = match snap.analysis.outgoing_calls(fpos)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1109,8 +1130,8 @@ pub fn handle_call_hierarchy_outgoing(
 
     for call_item in call_items.into_iter() {
         let file_id = call_item.target.file_id();
-        let line_index = world.analysis().file_line_index(file_id)?;
-        let item = to_proto::call_hierarchy_item(&world, call_item.target)?;
+        let line_index = snap.analysis.file_line_index(file_id)?;
+        let item = to_proto::call_hierarchy_item(&snap, call_item.target)?;
         res.push(CallHierarchyOutgoingCall {
             to: item,
             from_ranges: call_item
@@ -1124,83 +1145,204 @@ pub fn handle_call_hierarchy_outgoing(
     Ok(Some(res))
 }
 
-pub fn handle_semantic_tokens(
-    world: WorldSnapshot,
+pub(crate) fn handle_semantic_tokens(
+    snap: GlobalStateSnapshot,
     params: SemanticTokensParams,
 ) -> Result<Option<SemanticTokensResult>> {
     let _p = profile("handle_semantic_tokens");
 
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let text = world.analysis().file_text(file_id)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let text = snap.analysis.file_text(file_id)?;
+    let line_index = snap.analysis.file_line_index(file_id)?;
 
-    let highlights = world.analysis().highlight(file_id)?;
+    let highlights = snap.analysis.highlight(file_id)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
     Ok(Some(semantic_tokens.into()))
 }
 
-pub fn handle_semantic_tokens_range(
-    world: WorldSnapshot,
+pub(crate) fn handle_semantic_tokens_range(
+    snap: GlobalStateSnapshot,
     params: SemanticTokensRangeParams,
 ) -> Result<Option<SemanticTokensRangeResult>> {
     let _p = profile("handle_semantic_tokens_range");
 
-    let frange = from_proto::file_range(&world, params.text_document, params.range)?;
-    let text = world.analysis().file_text(frange.file_id)?;
-    let line_index = world.analysis().file_line_index(frange.file_id)?;
+    let frange = from_proto::file_range(&snap, params.text_document, params.range)?;
+    let text = snap.analysis.file_text(frange.file_id)?;
+    let line_index = snap.analysis.file_line_index(frange.file_id)?;
 
-    let highlights = world.analysis().highlight_range(frange)?;
+    let highlights = snap.analysis.highlight_range(frange)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
     Ok(Some(semantic_tokens.into()))
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+fn implementation_title(count: usize) -> String {
+    if count == 1 {
+        "1 implementation".into()
+    } else {
+        format!("{} implementations", count)
+    }
+}
+
+fn show_references_command(
+    title: String,
+    uri: &lsp_types::Url,
+    position: lsp_types::Position,
+    locations: Vec<lsp_types::Location>,
+) -> Command {
+    // We cannot use the 'editor.action.showReferences' command directly
+    // because that command requires vscode types which we convert in the handler
+    // on the client side.
+
+    Command {
+        title,
+        command: "rust-analyzer.showReferences".into(),
+        arguments: Some(vec![
+            to_value(uri).unwrap(),
+            to_value(position).unwrap(),
+            to_value(locations).unwrap(),
+        ]),
+    }
+}
+
+fn run_single_command(runnable: &lsp_ext::Runnable, title: &str) -> Command {
+    Command {
+        title: title.to_string(),
+        command: "rust-analyzer.runSingle".into(),
+        arguments: Some(vec![to_value(runnable).unwrap()]),
+    }
+}
 
-    use mbe::{ast_to_token_tree, TokenMap};
-    use ra_cfg::parse_cfg;
-    use ra_syntax::{
-        ast::{self, AstNode},
-        SmolStr,
+fn debug_single_command(runnable: &lsp_ext::Runnable) -> Command {
+    Command {
+        title: "Debug".into(),
+        command: "rust-analyzer.debugSingle".into(),
+        arguments: Some(vec![to_value(runnable).unwrap()]),
+    }
+}
+
+fn goto_location_command(snap: &GlobalStateSnapshot, nav: &NavigationTarget) -> Option<Command> {
+    let value = if snap.config.client_caps.location_link {
+        let link = to_proto::location_link(snap, None, nav.clone()).ok()?;
+        to_value(link).ok()?
+    } else {
+        let range = FileRange { file_id: nav.file_id(), range: nav.range() };
+        let location = to_proto::location(snap, range).ok()?;
+        to_value(location).ok()?
     };
 
-    fn get_token_tree_generated(input: &str) -> (tt::Subtree, TokenMap) {
-        let source_file = ast::SourceFile::parse(input).ok().unwrap();
-        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
-        ast_to_token_tree(&tt).unwrap()
+    Some(Command {
+        title: nav.name().to_string(),
+        command: "rust-analyzer.gotoLocation".into(),
+        arguments: Some(vec![value]),
+    })
+}
+
+fn to_command_link(command: Command, tooltip: String) -> lsp_ext::CommandLink {
+    lsp_ext::CommandLink { tooltip: Some(tooltip), command }
+}
+
+fn show_impl_command_link(
+    snap: &GlobalStateSnapshot,
+    position: &FilePosition,
+) -> Option<lsp_ext::CommandLinkGroup> {
+    if snap.config.hover.implementations {
+        if let Some(nav_data) = snap.analysis.goto_implementation(*position).unwrap_or(None) {
+            let uri = to_proto::url(snap, position.file_id);
+            let line_index = snap.analysis.file_line_index(position.file_id).ok()?;
+            let position = to_proto::position(&line_index, position.offset);
+            let locations: Vec<_> = nav_data
+                .info
+                .into_iter()
+                .filter_map(|nav| to_proto::location_from_nav(snap, nav).ok())
+                .collect();
+            let title = implementation_title(locations.len());
+            let command = show_references_command(title, &uri, position, locations);
+
+            return Some(lsp_ext::CommandLinkGroup {
+                commands: vec![to_command_link(command, "Go to implementations".into())],
+                ..Default::default()
+            });
+        }
     }
+    None
+}
 
-    #[test]
-    fn test_cfg_expr_minimal_features_needed() {
-        let (subtree, _) = get_token_tree_generated(r#"#![cfg(feature = "baz")]"#);
-        let cfg_expr = parse_cfg(&subtree);
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
+fn runnable_action_links(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    runnable: Runnable,
+) -> Option<lsp_ext::CommandLinkGroup> {
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id).ok()?;
+    if !snap.config.hover.runnable() || should_skip_target(&runnable, cargo_spec.as_ref()) {
+        return None;
+    }
 
-        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+    let action: &'static _ = runnable.action();
+    to_proto::runnable(snap, file_id, runnable).ok().map(|r| {
+        let mut group = lsp_ext::CommandLinkGroup::default();
 
-        let (subtree, _) =
-            get_token_tree_generated(r#"#![cfg(all(feature = "baz", feature = "foo"))]"#);
-        let cfg_expr = parse_cfg(&subtree);
+        if snap.config.hover.run {
+            let run_command = run_single_command(&r, action.run_title);
+            group.commands.push(to_command_link(run_command, r.label.clone()));
+        }
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert_eq!(min_features, vec![SmolStr::new("baz"), SmolStr::new("foo")]);
+        if snap.config.hover.debug {
+            let dbg_command = debug_single_command(&r);
+            group.commands.push(to_command_link(dbg_command, r.label));
+        }
+
+        group
+    })
+}
 
-        let (subtree, _) =
-            get_token_tree_generated(r#"#![cfg(any(feature = "baz", feature = "foo", unix))]"#);
-        let cfg_expr = parse_cfg(&subtree);
+fn goto_type_action_links(
+    snap: &GlobalStateSnapshot,
+    nav_targets: &[HoverGotoTypeData],
+) -> Option<lsp_ext::CommandLinkGroup> {
+    if !snap.config.hover.goto_type_def || nav_targets.is_empty() {
+        return None;
+    }
+
+    Some(lsp_ext::CommandLinkGroup {
+        title: Some("Go to ".into()),
+        commands: nav_targets
+            .iter()
+            .filter_map(|it| {
+                goto_location_command(snap, &it.nav)
+                    .map(|cmd| to_command_link(cmd, it.mod_path.clone()))
+            })
+            .collect(),
+    })
+}
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+fn prepare_hover_actions(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    actions: &[HoverAction],
+) -> Vec<lsp_ext::CommandLinkGroup> {
+    if snap.config.hover.none() || !snap.config.client_caps.hover_actions {
+        return Vec::new();
+    }
 
-        let (subtree, _) = get_token_tree_generated(r#"#![cfg(foo)]"#);
-        let cfg_expr = parse_cfg(&subtree);
+    actions
+        .iter()
+        .filter_map(|it| match it {
+            HoverAction::Implementaion(position) => show_impl_command_link(snap, position),
+            HoverAction::Runnable(r) => runnable_action_links(snap, file_id, r.clone()),
+            HoverAction::GoToType(targets) => goto_type_action_links(snap, targets),
+        })
+        .collect()
+}
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert!(min_features.is_empty());
+fn should_skip_target(runnable: &Runnable, cargo_spec: Option<&CargoTargetSpec>) -> bool {
+    match runnable.kind {
+        RunnableKind::Bin => {
+            // Do not suggest binary run on other target than binary
+            match &cargo_spec {
+                Some(spec) => !matches!(spec.target_kind, TargetKind::Bin | TargetKind::Example),
+                None => true,
+            }
+        }
+        _ => false,
     }
 }
diff --git a/crates/rust-analyzer/src/lib.rs b/crates/rust-analyzer/src/lib.rs
index 57d0e9218..369830973 100644
--- a/crates/rust-analyzer/src/lib.rs
+++ b/crates/rust-analyzer/src/lib.rs
@@ -17,30 +17,74 @@ macro_rules! eprintln {
     ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
 }
 
-mod vfs_glob;
+mod global_state;
+mod reload;
+mod main_loop;
+mod dispatch;
+mod handlers;
 mod caps;
 mod cargo_target_spec;
 mod to_proto;
 mod from_proto;
-mod main_loop;
+mod semantic_tokens;
 mod markdown;
+mod diagnostics;
+mod line_endings;
+mod request_metrics;
+mod lsp_utils;
+mod thread_pool;
 pub mod lsp_ext;
 pub mod config;
-mod world;
-mod diagnostics;
-mod semantic_tokens;
 
 use serde::de::DeserializeOwned;
 
-pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
-pub use crate::{
-    caps::server_capabilities,
-    main_loop::LspError,
-    main_loop::{main_loop, show_message},
-};
+pub type Result<T, E = Box<dyn std::error::Error + Send + Sync>> = std::result::Result<T, E>;
+pub use crate::{caps::server_capabilities, main_loop::main_loop};
+use ra_ide::AnalysisHost;
+use std::fmt;
+use vfs::Vfs;
 
 pub fn from_json<T: DeserializeOwned>(what: &'static str, json: serde_json::Value) -> Result<T> {
     let res = T::deserialize(&json)
         .map_err(|e| format!("Failed to deserialize {}: {}; {}", what, e, json))?;
     Ok(res)
 }
+
+#[derive(Debug)]
+struct LspError {
+    code: i32,
+    message: String,
+}
+
+impl LspError {
+    fn new(code: i32, message: String) -> LspError {
+        LspError { code, message }
+    }
+}
+
+impl fmt::Display for LspError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Language Server request failed with {}. ({})", self.code, self.message)
+    }
+}
+
+impl std::error::Error for LspError {}
+
+fn print_memory_usage(mut host: AnalysisHost, vfs: Vfs) {
+    let mut mem = host.per_query_memory_usage();
+
+    let before = ra_prof::memory_usage();
+    drop(vfs);
+    let vfs = before.allocated - ra_prof::memory_usage().allocated;
+    mem.push(("VFS".into(), vfs));
+
+    let before = ra_prof::memory_usage();
+    drop(host);
+    mem.push(("Unaccounted".into(), before.allocated - ra_prof::memory_usage().allocated));
+
+    mem.push(("Remaining".into(), ra_prof::memory_usage().allocated));
+
+    for (name, bytes) in mem {
+        println!("{:>8} {}", bytes, name);
+    }
+}
diff --git a/crates/rust-analyzer/src/line_endings.rs b/crates/rust-analyzer/src/line_endings.rs
new file mode 100644
index 000000000..9f892f32e
--- /dev/null
+++ b/crates/rust-analyzer/src/line_endings.rs
@@ -0,0 +1,52 @@
+//! We maintain invariant that all internal strings use `\n` as line separator.
+//! This module does line ending conversion and detection (so that we can
+//! convert back to `\r\n` on the way out).
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) enum LineEndings {
+    Unix,
+    Dos,
+}
+
+impl LineEndings {
+    /// Replaces `\r\n` with `\n` in-place in `src`.
+    pub(crate) fn normalize(src: String) -> (String, LineEndings) {
+        if !src.as_bytes().contains(&b'\r') {
+            return (src, LineEndings::Unix);
+        }
+
+        // We replace `\r\n` with `\n` in-place, which doesn't break utf-8 encoding.
+        // While we *can* call `as_mut_vec` and do surgery on the live string
+        // directly, let's rather steal the contents of `src`. This makes the code
+        // safe even if a panic occurs.
+
+        let mut buf = src.into_bytes();
+        let mut gap_len = 0;
+        let mut tail = buf.as_mut_slice();
+        loop {
+            let idx = match find_crlf(&tail[gap_len..]) {
+                None => tail.len(),
+                Some(idx) => idx + gap_len,
+            };
+            tail.copy_within(gap_len..idx, 0);
+            tail = &mut tail[idx - gap_len..];
+            if tail.len() == gap_len {
+                break;
+            }
+            gap_len += 1;
+        }
+
+        // Account for removed `\r`.
+        // After `set_len`, `buf` is guaranteed to contain utf-8 again.
+        let new_len = buf.len() - gap_len;
+        let src = unsafe {
+            buf.set_len(new_len);
+            String::from_utf8_unchecked(buf)
+        };
+        return (src, LineEndings::Dos);
+
+        fn find_crlf(src: &[u8]) -> Option<usize> {
+            src.iter().zip(src.iter().skip(1)).position(|it| it == (&b'\r', &b'\n'))
+        }
+    }
+}
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index acb1dacb6..e216966a9 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -3,8 +3,9 @@
 use std::{collections::HashMap, path::PathBuf};
 
 use lsp_types::request::Request;
-use lsp_types::{Position, Range, TextDocumentIdentifier};
-use rustc_hash::FxHashMap;
+use lsp_types::{
+    notification::Notification, CodeActionKind, Position, Range, TextDocumentIdentifier,
+};
 use serde::{Deserialize, Serialize};
 
 pub enum AnalyzerStatus {}
@@ -15,12 +16,20 @@ impl Request for AnalyzerStatus {
     const METHOD: &'static str = "rust-analyzer/analyzerStatus";
 }
 
-pub enum CollectGarbage {}
+pub enum MemoryUsage {}
 
-impl Request for CollectGarbage {
+impl Request for MemoryUsage {
+    type Params = ();
+    type Result = String;
+    const METHOD: &'static str = "rust-analyzer/memoryUsage";
+}
+
+pub enum ReloadWorkspace {}
+
+impl Request for ReloadWorkspace {
     type Params = ();
     type Result = ();
-    const METHOD: &'static str = "rust-analyzer/collectGarbage";
+    const METHOD: &'static str = "rust-analyzer/reloadWorkspace";
 }
 
 pub enum SyntaxTree {}
@@ -98,6 +107,22 @@ pub struct JoinLinesParams {
     pub ranges: Vec<Range>,
 }
 
+pub enum ResolveCodeActionRequest {}
+
+impl Request for ResolveCodeActionRequest {
+    type Params = ResolveCodeActionParams;
+    type Result = Option<SnippetWorkspaceEdit>;
+    const METHOD: &'static str = "experimental/resolveCodeAction";
+}
+
+/// Params for the ResolveCodeActionRequest
+#[derive(Debug, Eq, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ResolveCodeActionParams {
+    pub code_action_params: lsp_types::CodeActionParams,
+    pub id: String,
+}
+
 pub enum OnEnter {}
 
 impl Request for OnEnter {
@@ -111,7 +136,7 @@ pub enum Runnables {}
 impl Request for Runnables {
     type Params = RunnablesParams;
     type Result = Vec<Runnable>;
-    const METHOD: &'static str = "rust-analyzer/runnables";
+    const METHOD: &'static str = "experimental/runnables";
 }
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -124,13 +149,30 @@ pub struct RunnablesParams {
 #[derive(Deserialize, Serialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct Runnable {
-    pub range: Range,
     pub label: String,
-    pub bin: String,
-    pub args: Vec<String>,
-    pub extra_args: Vec<String>,
-    pub env: FxHashMap<String, String>,
-    pub cwd: Option<PathBuf>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub location: Option<lsp_types::LocationLink>,
+    pub kind: RunnableKind,
+    pub args: CargoRunnable,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(rename_all = "lowercase")]
+pub enum RunnableKind {
+    Cargo,
+}
+
+#[derive(Deserialize, Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct CargoRunnable {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub workspace_root: Option<PathBuf>,
+    // command, --package and --lib stuff
+    pub cargo_args: Vec<String>,
+    // stuff after --
+    pub executable_args: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub expect_test: Option<bool>,
 }
 
 pub enum InlayHints {}
@@ -176,6 +218,22 @@ pub struct SsrParams {
     pub parse_only: bool,
 }
 
+pub enum StatusNotification {}
+
+#[serde(rename_all = "camelCase")]
+#[derive(Serialize, Deserialize)]
+pub enum Status {
+    Loading,
+    Ready,
+    NeedsReload,
+    Invalid,
+}
+
+impl Notification for StatusNotification {
+    type Params = Status;
+    const METHOD: &'static str = "rust-analyzer/status";
+}
+
 pub enum CodeActionRequest {}
 
 impl Request for CodeActionRequest {
@@ -188,11 +246,14 @@ impl Request for CodeActionRequest {
 pub struct CodeAction {
     pub title: String,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub group: Option<String>,
+    pub id: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub kind: Option<String>,
+    pub group: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub command: Option<lsp_types::Command>,
+    pub kind: Option<CodeActionKind>,
+    // We don't handle commands on the client-side
+    // #[serde(skip_serializing_if = "Option::is_none")]
+    // pub command: Option<lsp_types::Command>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub edit: Option<SnippetWorkspaceEdit>,
 }
@@ -228,3 +289,35 @@ pub struct SnippetTextEdit {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub insert_text_format: Option<lsp_types::InsertTextFormat>,
 }
+
+pub enum HoverRequest {}
+
+impl Request for HoverRequest {
+    type Params = lsp_types::HoverParams;
+    type Result = Option<Hover>;
+    const METHOD: &'static str = "textDocument/hover";
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+pub struct Hover {
+    #[serde(flatten)]
+    pub hover: lsp_types::Hover,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub actions: Vec<CommandLinkGroup>,
+}
+
+#[derive(Debug, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct CommandLinkGroup {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub title: Option<String>,
+    pub commands: Vec<CommandLink>,
+}
+
+// LSP v3.15 Command does not have a `tooltip` field, vscode supports one.
+#[derive(Debug, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct CommandLink {
+    #[serde(flatten)]
+    pub command: lsp_types::Command,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tooltip: Option<String>,
+}
diff --git a/crates/rust-analyzer/src/lsp_utils.rs b/crates/rust-analyzer/src/lsp_utils.rs
new file mode 100644
index 000000000..0bc3ff115
--- /dev/null
+++ b/crates/rust-analyzer/src/lsp_utils.rs
@@ -0,0 +1,195 @@
+//! Utilities for LSP-related boilerplate code.
+use std::{error::Error, ops::Range};
+
+use lsp_server::Notification;
+use ra_db::Canceled;
+use ra_ide::LineIndex;
+
+use crate::{from_proto, global_state::GlobalState};
+
+pub(crate) fn is_canceled(e: &(dyn Error + 'static)) -> bool {
+    e.downcast_ref::<Canceled>().is_some()
+}
+
+pub(crate) fn notification_is<N: lsp_types::notification::Notification>(
+    notification: &Notification,
+) -> bool {
+    notification.method == N::METHOD
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub(crate) enum Progress {
+    Begin,
+    Report,
+    End,
+}
+
+impl Progress {
+    pub(crate) fn percentage(done: usize, total: usize) -> f64 {
+        (done as f64 / total.max(1) as f64) * 100.0
+    }
+}
+
+impl GlobalState {
+    pub(crate) fn show_message(&mut self, typ: lsp_types::MessageType, message: String) {
+        let message = message.into();
+        self.send_notification::<lsp_types::notification::ShowMessage>(
+            lsp_types::ShowMessageParams { typ, message },
+        )
+    }
+
+    pub(crate) fn report_progress(
+        &mut self,
+        title: &str,
+        state: Progress,
+        message: Option<String>,
+        percentage: Option<f64>,
+    ) {
+        if !self.config.client_caps.work_done_progress {
+            return;
+        }
+        let token = lsp_types::ProgressToken::String(format!("rustAnalyzer/{}", title));
+        let work_done_progress = match state {
+            Progress::Begin => {
+                self.send_request::<lsp_types::request::WorkDoneProgressCreate>(
+                    lsp_types::WorkDoneProgressCreateParams { token: token.clone() },
+                    |_, _| (),
+                );
+
+                lsp_types::WorkDoneProgress::Begin(lsp_types::WorkDoneProgressBegin {
+                    title: title.into(),
+                    cancellable: None,
+                    message,
+                    percentage,
+                })
+            }
+            Progress::Report => {
+                lsp_types::WorkDoneProgress::Report(lsp_types::WorkDoneProgressReport {
+                    cancellable: None,
+                    message,
+                    percentage,
+                })
+            }
+            Progress::End => {
+                lsp_types::WorkDoneProgress::End(lsp_types::WorkDoneProgressEnd { message })
+            }
+        };
+        self.send_notification::<lsp_types::notification::Progress>(lsp_types::ProgressParams {
+            token,
+            value: lsp_types::ProgressParamsValue::WorkDone(work_done_progress),
+        });
+    }
+}
+
+pub(crate) fn apply_document_changes(
+    old_text: &mut String,
+    content_changes: Vec<lsp_types::TextDocumentContentChangeEvent>,
+) {
+    let mut line_index = LineIndex::new(old_text);
+    // The changes we got must be applied sequentially, but can cross lines so we
+    // have to keep our line index updated.
+    // Some clients (e.g. Code) sort the ranges in reverse. As an optimization, we
+    // remember the last valid line in the index and only rebuild it if needed.
+    // The VFS will normalize the end of lines to `\n`.
+    enum IndexValid {
+        All,
+        UpToLineExclusive(u64),
+    }
+
+    impl IndexValid {
+        fn covers(&self, line: u64) -> bool {
+            match *self {
+                IndexValid::UpToLineExclusive(to) => to > line,
+                _ => true,
+            }
+        }
+    }
+
+    let mut index_valid = IndexValid::All;
+    for change in content_changes {
+        match change.range {
+            Some(range) => {
+                if !index_valid.covers(range.end.line) {
+                    line_index = LineIndex::new(&old_text);
+                }
+                index_valid = IndexValid::UpToLineExclusive(range.start.line);
+                let range = from_proto::text_range(&line_index, range);
+                old_text.replace_range(Range::<usize>::from(range), &change.text);
+            }
+            None => {
+                *old_text = change.text;
+                index_valid = IndexValid::UpToLineExclusive(0);
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use lsp_types::{Position, Range, TextDocumentContentChangeEvent};
+
+    use super::*;
+
+    #[test]
+    fn test_apply_document_changes() {
+        macro_rules! c {
+            [$($sl:expr, $sc:expr; $el:expr, $ec:expr => $text:expr),+] => {
+                vec![$(TextDocumentContentChangeEvent {
+                    range: Some(Range {
+                        start: Position { line: $sl, character: $sc },
+                        end: Position { line: $el, character: $ec },
+                    }),
+                    range_length: None,
+                    text: String::from($text),
+                }),+]
+            };
+        }
+
+        let mut text = String::new();
+        apply_document_changes(&mut text, vec![]);
+        assert_eq!(text, "");
+        apply_document_changes(
+            &mut text,
+            vec![TextDocumentContentChangeEvent {
+                range: None,
+                range_length: None,
+                text: String::from("the"),
+            }],
+        );
+        assert_eq!(text, "the");
+        apply_document_changes(&mut text, c![0, 3; 0, 3 => " quick"]);
+        assert_eq!(text, "the quick");
+        apply_document_changes(&mut text, c![0, 0; 0, 4 => "", 0, 5; 0, 5 => " foxes"]);
+        assert_eq!(text, "quick foxes");
+        apply_document_changes(&mut text, c![0, 11; 0, 11 => "\ndream"]);
+        assert_eq!(text, "quick foxes\ndream");
+        apply_document_changes(&mut text, c![1, 0; 1, 0 => "have "]);
+        assert_eq!(text, "quick foxes\nhave dream");
+        apply_document_changes(
+            &mut text,
+            c![0, 0; 0, 0 => "the ", 1, 4; 1, 4 => " quiet", 1, 16; 1, 16 => "s\n"],
+        );
+        assert_eq!(text, "the quick foxes\nhave quiet dreams\n");
+        apply_document_changes(&mut text, c![0, 15; 0, 15 => "\n", 2, 17; 2, 17 => "\n"]);
+        assert_eq!(text, "the quick foxes\n\nhave quiet dreams\n\n");
+        apply_document_changes(
+            &mut text,
+            c![1, 0; 1, 0 => "DREAM", 2, 0; 2, 0 => "they ", 3, 0; 3, 0 => "DON'T THEY?"],
+        );
+        assert_eq!(text, "the quick foxes\nDREAM\nthey have quiet dreams\nDON'T THEY?\n");
+        apply_document_changes(&mut text, c![0, 10; 1, 5 => "", 2, 0; 2, 12 => ""]);
+        assert_eq!(text, "the quick \nthey have quiet dreams\n");
+
+        text = String::from("❤️");
+        apply_document_changes(&mut text, c![0, 0; 0, 0 => "a"]);
+        assert_eq!(text, "a❤️");
+
+        text = String::from("a\nb");
+        apply_document_changes(&mut text, c![0, 1; 1, 0 => "\nțc", 0, 1; 1, 1 => "d"]);
+        assert_eq!(text, "adcb");
+
+        text = String::from("a\nb");
+        apply_document_changes(&mut text, c![0, 1; 1, 0 => "ț\nc", 0, 2; 0, 2 => "c"]);
+        assert_eq!(text, "ațc\ncb");
+    }
+}
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index f1287d52c..a41f7f564 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -1,75 +1,30 @@
 //! The main loop of `rust-analyzer` responsible for dispatching LSP
 //! requests/replies and notifications back to the client.
-
-mod handlers;
-mod subscriptions;
-pub(crate) mod pending_requests;
-
 use std::{
-    borrow::Cow,
-    env,
-    error::Error,
-    fmt,
-    ops::Range,
-    panic,
-    path::PathBuf,
-    sync::Arc,
+    env, fmt, panic,
     time::{Duration, Instant},
 };
 
-use crossbeam_channel::{never, select, unbounded, RecvError, Sender};
-use itertools::Itertools;
-use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
-use lsp_types::{
-    DidChangeTextDocumentParams, NumberOrString, TextDocumentContentChangeEvent, WorkDoneProgress,
-    WorkDoneProgressBegin, WorkDoneProgressCreateParams, WorkDoneProgressEnd,
-    WorkDoneProgressReport,
-};
-use ra_flycheck::{CheckTask, Status};
-use ra_ide::{Canceled, FileId, LibraryData, LineIndex, SourceRootId};
+use crossbeam_channel::{select, Receiver};
+use lsp_server::{Connection, Notification, Request, Response};
+use lsp_types::notification::Notification as _;
+use ra_db::VfsPath;
+use ra_ide::{Canceled, FileId};
 use ra_prof::profile;
-use ra_project_model::{PackageRoot, ProjectWorkspace};
-use ra_vfs::{VfsFile, VfsTask, Watch};
-use relative_path::RelativePathBuf;
-use rustc_hash::FxHashSet;
-use serde::{de::DeserializeOwned, Serialize};
-use threadpool::ThreadPool;
 
 use crate::{
-    config::{Config, FilesWatcher},
-    diagnostics::{to_proto::url_from_path_with_drive_lowercasing, DiagnosticTask},
-    from_proto, lsp_ext,
-    main_loop::{
-        pending_requests::{PendingRequest, PendingRequests},
-        subscriptions::Subscriptions,
-    },
-    world::{WorldSnapshot, WorldState},
+    config::Config,
+    dispatch::{NotificationDispatcher, RequestDispatcher},
+    from_proto,
+    global_state::{file_id_to_url, url_to_file_id, GlobalState, Status},
+    handlers, lsp_ext,
+    lsp_utils::{apply_document_changes, is_canceled, notification_is, Progress},
     Result,
 };
+use ra_project_model::ProjectWorkspace;
+use vfs::ChangeKind;
 
-#[derive(Debug)]
-pub struct LspError {
-    pub code: i32,
-    pub message: String,
-}
-
-impl LspError {
-    pub const UNKNOWN_FILE: i32 = -32900;
-
-    pub fn new(code: i32, message: String) -> LspError {
-        LspError { code, message }
-    }
-}
-
-impl fmt::Display for LspError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "Language Server request failed with {}. ({})", self.code, self.message)
-    }
-}
-
-impl Error for LspError {}
-
-pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection) -> Result<()> {
+pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
     log::info!("initial config: {:#?}", config);
 
     // Windows scheduler implements priority boosts: if thread waits for an
@@ -91,163 +46,22 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
         SetThreadPriority(thread, thread_priority_above_normal);
     }
 
-    let mut loop_state = LoopState::default();
-    let mut world_state = {
-        let workspaces = {
-            // FIXME: support dynamic workspace loading.
-            let project_roots: FxHashSet<_> = ws_roots
-                .iter()
-                .filter_map(|it| ra_project_model::ProjectRoot::discover(it).ok())
-                .flatten()
-                .collect();
-
-            if project_roots.is_empty() && config.notifications.cargo_toml_not_found {
-                show_message(
-                    lsp_types::MessageType::Error,
-                    format!(
-                        "rust-analyzer failed to discover workspace, no Cargo.toml found, dirs searched: {}",
-                        ws_roots.iter().format_with(", ", |it, f| f(&it.display()))
-                    ),
-                    &connection.sender,
-                );
-            };
-
-            project_roots
-                .into_iter()
-                .filter_map(|root| {
-                    ra_project_model::ProjectWorkspace::load(
-                        root,
-                        &config.cargo,
-                        config.with_sysroot,
-                    )
-                    .map_err(|err| {
-                        log::error!("failed to load workspace: {:#}", err);
-                        show_message(
-                            lsp_types::MessageType::Error,
-                            format!("rust-analyzer failed to load workspace: {:#}", err),
-                            &connection.sender,
-                        );
-                    })
-                    .ok()
-                })
-                .collect::<Vec<_>>()
-        };
-
-        let globs = config
-            .files
-            .exclude
-            .iter()
-            .map(|glob| crate::vfs_glob::Glob::new(glob))
-            .collect::<std::result::Result<Vec<_>, _>>()?;
-
-        if let FilesWatcher::Client = config.files.watcher {
-            let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
-                watchers: workspaces
-                    .iter()
-                    .flat_map(ProjectWorkspace::to_roots)
-                    .filter(PackageRoot::is_member)
-                    .map(|root| format!("{}/**/*.rs", root.path().display()))
-                    .map(|glob_pattern| lsp_types::FileSystemWatcher { glob_pattern, kind: None })
-                    .collect(),
-            };
-            let registration = lsp_types::Registration {
-                id: "file-watcher".to_string(),
-                method: "workspace/didChangeWatchedFiles".to_string(),
-                register_options: Some(serde_json::to_value(registration_options).unwrap()),
-            };
-            let params = lsp_types::RegistrationParams { registrations: vec![registration] };
-            let request = request_new::<lsp_types::request::RegisterCapability>(
-                loop_state.next_request_id(),
-                params,
-            );
-            connection.sender.send(request.into()).unwrap();
-        }
-
-        WorldState::new(
-            ws_roots,
-            workspaces,
-            config.lru_capacity,
-            &globs,
-            Watch(matches!(config.files.watcher, FilesWatcher::Notify)),
-            config,
-        )
-    };
-
-    loop_state.roots_total = world_state.vfs.read().n_roots();
-
-    let pool = ThreadPool::default();
-    let (task_sender, task_receiver) = unbounded::<Task>();
-    let (libdata_sender, libdata_receiver) = unbounded::<LibraryData>();
-
-    log::info!("server initialized, serving requests");
-    {
-        let task_sender = task_sender;
-        let libdata_sender = libdata_sender;
-        loop {
-            log::trace!("selecting");
-            let event = select! {
-                recv(&connection.receiver) -> msg => match msg {
-                    Ok(msg) => Event::Msg(msg),
-                    Err(RecvError) => return Err("client exited without shutdown".into()),
-                },
-                recv(task_receiver) -> task => Event::Task(task.unwrap()),
-                recv(world_state.task_receiver) -> task => match task {
-                    Ok(task) => Event::Vfs(task),
-                    Err(RecvError) => return Err("vfs died".into()),
-                },
-                recv(libdata_receiver) -> data => Event::Lib(data.unwrap()),
-                recv(world_state.flycheck.as_ref().map_or(&never(), |it| &it.task_recv)) -> task => match task {
-                    Ok(task) => Event::CheckWatcher(task),
-                    Err(RecvError) => return Err("check watcher died".into()),
-                }
-            };
-            if let Event::Msg(Message::Request(req)) = &event {
-                if connection.handle_shutdown(&req)? {
-                    break;
-                };
-            }
-            loop_turn(
-                &pool,
-                &task_sender,
-                &libdata_sender,
-                &connection,
-                &mut world_state,
-                &mut loop_state,
-                event,
-            )?;
-        }
-    }
-    world_state.analysis_host.request_cancellation();
-    log::info!("waiting for tasks to finish...");
-    task_receiver.into_iter().for_each(|task| {
-        on_task(task, &connection.sender, &mut loop_state.pending_requests, &mut world_state)
-    });
-    libdata_receiver.into_iter().for_each(drop);
-    log::info!("...tasks have finished");
-    log::info!("joining threadpool...");
-    pool.join();
-    drop(pool);
-    log::info!("...threadpool has finished");
-
-    let vfs = Arc::try_unwrap(world_state.vfs).expect("all snapshots should be dead");
-    drop(vfs);
-
-    Ok(())
-}
-
-#[derive(Debug)]
-enum Task {
-    Respond(Response),
-    Notify(Notification),
-    Diagnostic(DiagnosticTask),
+    GlobalState::new(connection.sender.clone(), config).run(connection.receiver)
 }
 
 enum Event {
-    Msg(Message),
+    Lsp(lsp_server::Message),
     Task(Task),
-    Vfs(VfsTask),
-    Lib(LibraryData),
-    CheckWatcher(CheckTask),
+    Vfs(vfs::loader::Message),
+    Flycheck(flycheck::Message),
+}
+
+#[derive(Debug)]
+pub(crate) enum Task {
+    Response(Response),
+    Diagnostics(Vec<(FileId, Vec<lsp_types::Diagnostic>)>),
+    Workspaces(Vec<anyhow::Result<ProjectWorkspace>>),
+    Unit,
 }
 
 impl fmt::Debug for Event {
@@ -257,19 +71,14 @@ impl fmt::Debug for Event {
         };
 
         match self {
-            Event::Msg(Message::Notification(not)) => {
+            Event::Lsp(lsp_server::Message::Notification(not)) => {
                 if notification_is::<lsp_types::notification::DidOpenTextDocument>(not)
                     || notification_is::<lsp_types::notification::DidChangeTextDocument>(not)
                 {
                     return debug_verbose_not(not, f);
                 }
             }
-            Event::Task(Task::Notify(not)) => {
-                if notification_is::<lsp_types::notification::PublishDiagnostics>(not) {
-                    return debug_verbose_not(not, f);
-                }
-            }
-            Event::Task(Task::Respond(resp)) => {
+            Event::Task(Task::Response(resp)) => {
                 return f
                     .debug_struct("Response")
                     .field("id", &resp.id)
@@ -279,874 +88,441 @@ impl fmt::Debug for Event {
             _ => (),
         }
         match self {
-            Event::Msg(it) => fmt::Debug::fmt(it, f),
+            Event::Lsp(it) => fmt::Debug::fmt(it, f),
             Event::Task(it) => fmt::Debug::fmt(it, f),
             Event::Vfs(it) => fmt::Debug::fmt(it, f),
-            Event::Lib(it) => fmt::Debug::fmt(it, f),
-            Event::CheckWatcher(it) => fmt::Debug::fmt(it, f),
+            Event::Flycheck(it) => fmt::Debug::fmt(it, f),
         }
     }
 }
 
-#[derive(Debug, Default)]
-struct LoopState {
-    next_request_id: u64,
-    pending_responses: FxHashSet<RequestId>,
-    pending_requests: PendingRequests,
-    subscriptions: Subscriptions,
-    // We try not to index more than MAX_IN_FLIGHT_LIBS libraries at the same
-    // time to always have a thread ready to react to input.
-    in_flight_libraries: usize,
-    pending_libraries: Vec<(SourceRootId, Vec<(FileId, RelativePathBuf, Arc<String>)>)>,
-    workspace_loaded: bool,
-    roots_progress_reported: Option<usize>,
-    roots_scanned: usize,
-    roots_total: usize,
-    configuration_request_id: Option<RequestId>,
-}
-
-impl LoopState {
-    fn next_request_id(&mut self) -> RequestId {
-        self.next_request_id += 1;
-        let res: RequestId = self.next_request_id.into();
-        let inserted = self.pending_responses.insert(res.clone());
-        assert!(inserted);
-        res
-    }
-}
-
-fn loop_turn(
-    pool: &ThreadPool,
-    task_sender: &Sender<Task>,
-    libdata_sender: &Sender<LibraryData>,
-    connection: &Connection,
-    world_state: &mut WorldState,
-    loop_state: &mut LoopState,
-    event: Event,
-) -> Result<()> {
-    let loop_start = Instant::now();
-
-    // NOTE: don't count blocking select! call as a loop-turn time
-    let _p = profile("main_loop_inner/loop-turn");
-    log::info!("loop turn = {:?}", event);
-    let queue_count = pool.queued_count();
-    if queue_count > 0 {
-        log::info!("queued count = {}", queue_count);
-    }
-
-    match event {
-        Event::Task(task) => {
-            on_task(task, &connection.sender, &mut loop_state.pending_requests, world_state);
-            world_state.maybe_collect_garbage();
-        }
-        Event::Vfs(task) => {
-            world_state.vfs.write().handle_task(task);
-        }
-        Event::Lib(lib) => {
-            world_state.add_lib(lib);
-            world_state.maybe_collect_garbage();
-            loop_state.in_flight_libraries -= 1;
-            loop_state.roots_scanned += 1;
-        }
-        Event::CheckWatcher(task) => on_check_task(task, world_state, task_sender)?,
-        Event::Msg(msg) => match msg {
-            Message::Request(req) => on_request(
-                world_state,
-                &mut loop_state.pending_requests,
-                pool,
-                task_sender,
-                &connection.sender,
-                loop_start,
-                req,
-            )?,
-            Message::Notification(not) => {
-                on_notification(&connection.sender, world_state, loop_state, not)?;
-            }
-            Message::Response(resp) => {
-                let removed = loop_state.pending_responses.remove(&resp.id);
-                if !removed {
-                    log::error!("unexpected response: {:?}", resp)
-                }
-
-                if Some(&resp.id) == loop_state.configuration_request_id.as_ref() {
-                    loop_state.configuration_request_id = None;
-                    log::debug!("config update response: '{:?}", resp);
-                    let Response { error, result, .. } = resp;
+impl GlobalState {
+    fn next_event(&self, inbox: &Receiver<lsp_server::Message>) -> Option<Event> {
+        select! {
+            recv(inbox) -> msg =>
+                msg.ok().map(Event::Lsp),
 
-                    match (error, result) {
-                        (Some(err), _) => {
-                            log::error!("failed to fetch the server settings: {:?}", err)
-                        }
-                        (None, Some(configs)) => {
-                            if let Some(new_config) = configs.get(0) {
-                                let mut config = world_state.config.clone();
-                                config.update(&new_config);
-                                world_state.update_configuration(config);
-                            }
-                        }
-                        (None, None) => {
-                            log::error!("received empty server settings response from the client")
-                        }
-                    }
-                }
-            }
-        },
-    };
+            recv(self.task_pool.receiver) -> task =>
+                Some(Event::Task(task.unwrap())),
 
-    let mut state_changed = false;
-    if let Some(changes) = world_state.process_changes(&mut loop_state.roots_scanned) {
-        state_changed = true;
-        loop_state.pending_libraries.extend(changes);
-    }
+            recv(self.loader.receiver) -> task =>
+                Some(Event::Vfs(task.unwrap())),
 
-    let max_in_flight_libs = pool.max_count().saturating_sub(2).max(1);
-    while loop_state.in_flight_libraries < max_in_flight_libs {
-        let (root, files) = match loop_state.pending_libraries.pop() {
-            Some(it) => it,
-            None => break,
-        };
-
-        loop_state.in_flight_libraries += 1;
-        let sender = libdata_sender.clone();
-        pool.execute(move || {
-            log::info!("indexing {:?} ... ", root);
-            let data = LibraryData::prepare(root, files);
-            sender.send(data).unwrap();
-        });
-    }
-
-    let show_progress =
-        !loop_state.workspace_loaded && world_state.config.client_caps.work_done_progress;
-
-    if !loop_state.workspace_loaded
-        && loop_state.roots_scanned == loop_state.roots_total
-        && loop_state.pending_libraries.is_empty()
-        && loop_state.in_flight_libraries == 0
-    {
-        state_changed = true;
-        loop_state.workspace_loaded = true;
-        if let Some(flycheck) = &world_state.flycheck {
-            flycheck.update();
+            recv(self.flycheck_receiver) -> task =>
+                Some(Event::Flycheck(task.unwrap())),
         }
     }
 
-    if show_progress {
-        send_startup_progress(&connection.sender, loop_state);
-    }
-
-    if state_changed && loop_state.workspace_loaded {
-        update_file_notifications_on_threadpool(
-            pool,
-            world_state.snapshot(),
-            task_sender.clone(),
-            loop_state.subscriptions.subscriptions(),
-        );
-        pool.execute({
-            let subs = loop_state.subscriptions.subscriptions();
-            let snap = world_state.snapshot();
-            move || snap.analysis().prime_caches(subs).unwrap_or_else(|_: Canceled| ())
-        });
-    }
-
-    let loop_duration = loop_start.elapsed();
-    if loop_duration > Duration::from_millis(100) {
-        log::error!("overly long loop turn: {:?}", loop_duration);
-        if env::var("RA_PROFILE").is_ok() {
-            show_message(
+    fn run(mut self, inbox: Receiver<lsp_server::Message>) -> Result<()> {
+        if self.config.linked_projects.is_empty() && self.config.notifications.cargo_toml_not_found
+        {
+            self.show_message(
                 lsp_types::MessageType::Error,
-                format!("overly long loop turn: {:?}", loop_duration),
-                &connection.sender,
+                "rust-analyzer failed to discover workspace".to_string(),
             );
-        }
-    }
+        };
 
-    Ok(())
-}
+        let save_registration_options = lsp_types::TextDocumentSaveRegistrationOptions {
+            include_text: Some(false),
+            text_document_registration_options: lsp_types::TextDocumentRegistrationOptions {
+                document_selector: Some(vec![
+                    lsp_types::DocumentFilter {
+                        language: None,
+                        scheme: None,
+                        pattern: Some("**/*.rs".into()),
+                    },
+                    lsp_types::DocumentFilter {
+                        language: None,
+                        scheme: None,
+                        pattern: Some("**/Cargo.toml".into()),
+                    },
+                    lsp_types::DocumentFilter {
+                        language: None,
+                        scheme: None,
+                        pattern: Some("**/Cargo.lock".into()),
+                    },
+                ]),
+            },
+        };
 
-fn on_task(
-    task: Task,
-    msg_sender: &Sender<Message>,
-    pending_requests: &mut PendingRequests,
-    state: &mut WorldState,
-) {
-    match task {
-        Task::Respond(response) => {
-            if let Some(completed) = pending_requests.finish(&response.id) {
-                log::info!("handled req#{} in {:?}", completed.id, completed.duration);
-                state.complete_request(completed);
-                msg_sender.send(response.into()).unwrap();
-            }
-        }
-        Task::Notify(n) => {
-            msg_sender.send(n.into()).unwrap();
-        }
-        Task::Diagnostic(task) => on_diagnostic_task(task, msg_sender, state),
-    }
-}
+        let registration = lsp_types::Registration {
+            id: "textDocument/didSave".to_string(),
+            method: "textDocument/didSave".to_string(),
+            register_options: Some(serde_json::to_value(save_registration_options).unwrap()),
+        };
+        self.send_request::<lsp_types::request::RegisterCapability>(
+            lsp_types::RegistrationParams { registrations: vec![registration] },
+            |_, _| (),
+        );
 
-fn on_request(
-    world: &mut WorldState,
-    pending_requests: &mut PendingRequests,
-    pool: &ThreadPool,
-    task_sender: &Sender<Task>,
-    msg_sender: &Sender<Message>,
-    request_received: Instant,
-    req: Request,
-) -> Result<()> {
-    let mut pool_dispatcher = PoolDispatcher {
-        req: Some(req),
-        pool,
-        world,
-        task_sender,
-        msg_sender,
-        pending_requests,
-        request_received,
-    };
-    pool_dispatcher
-        .on_sync::<lsp_ext::CollectGarbage>(|s, ()| Ok(s.collect_garbage()))?
-        .on_sync::<lsp_ext::JoinLines>(|s, p| handlers::handle_join_lines(s.snapshot(), p))?
-        .on_sync::<lsp_ext::OnEnter>(|s, p| handlers::handle_on_enter(s.snapshot(), p))?
-        .on_sync::<lsp_types::request::SelectionRangeRequest>(|s, p| {
-            handlers::handle_selection_range(s.snapshot(), p)
-        })?
-        .on_sync::<lsp_ext::MatchingBrace>(|s, p| handlers::handle_matching_brace(s.snapshot(), p))?
-        .on::<lsp_ext::AnalyzerStatus>(handlers::handle_analyzer_status)?
-        .on::<lsp_ext::SyntaxTree>(handlers::handle_syntax_tree)?
-        .on::<lsp_ext::ExpandMacro>(handlers::handle_expand_macro)?
-        .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)?
-        .on::<lsp_ext::Runnables>(handlers::handle_runnables)?
-        .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)?
-        .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)?
-        .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)?
-        .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)?
-        .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
-        .on::<lsp_types::request::GotoDefinition>(handlers::handle_goto_definition)?
-        .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)?
-        .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)?
-        .on::<lsp_types::request::Completion>(handlers::handle_completion)?
-        .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)?
-        .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)?
-        .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)?
-        .on::<lsp_types::request::SignatureHelpRequest>(handlers::handle_signature_help)?
-        .on::<lsp_types::request::HoverRequest>(handlers::handle_hover)?
-        .on::<lsp_types::request::PrepareRenameRequest>(handlers::handle_prepare_rename)?
-        .on::<lsp_types::request::Rename>(handlers::handle_rename)?
-        .on::<lsp_types::request::References>(handlers::handle_references)?
-        .on::<lsp_types::request::Formatting>(handlers::handle_formatting)?
-        .on::<lsp_types::request::DocumentHighlightRequest>(handlers::handle_document_highlight)?
-        .on::<lsp_types::request::CallHierarchyPrepare>(handlers::handle_call_hierarchy_prepare)?
-        .on::<lsp_types::request::CallHierarchyIncomingCalls>(
-            handlers::handle_call_hierarchy_incoming,
-        )?
-        .on::<lsp_types::request::CallHierarchyOutgoingCalls>(
-            handlers::handle_call_hierarchy_outgoing,
-        )?
-        .on::<lsp_types::request::SemanticTokensRequest>(handlers::handle_semantic_tokens)?
-        .on::<lsp_types::request::SemanticTokensRangeRequest>(
-            handlers::handle_semantic_tokens_range,
-        )?
-        .on::<lsp_ext::Ssr>(handlers::handle_ssr)?
-        .finish();
-    Ok(())
-}
+        self.fetch_workspaces();
 
-fn on_notification(
-    msg_sender: &Sender<Message>,
-    state: &mut WorldState,
-    loop_state: &mut LoopState,
-    not: Notification,
-) -> Result<()> {
-    let not = match notification_cast::<lsp_types::notification::Cancel>(not) {
-        Ok(params) => {
-            let id: RequestId = match params.id {
-                NumberOrString::Number(id) => id.into(),
-                NumberOrString::String(id) => id.into(),
-            };
-            if loop_state.pending_requests.cancel(&id) {
-                let response = Response::new_err(
-                    id,
-                    ErrorCode::RequestCanceled as i32,
-                    "canceled by client".to_string(),
-                );
-                msg_sender.send(response.into()).unwrap()
-            }
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidOpenTextDocument>(not) {
-        Ok(params) => {
-            let uri = params.text_document.uri;
-            let path = uri.to_file_path().map_err(|()| format!("invalid uri: {}", uri))?;
-            if let Some(file_id) =
-                state.vfs.write().add_file_overlay(&path, params.text_document.text)
-            {
-                loop_state.subscriptions.add_sub(FileId(file_id.0));
-            }
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidChangeTextDocument>(not) {
-        Ok(params) => {
-            let DidChangeTextDocumentParams { text_document, content_changes } = params;
-            let world = state.snapshot();
-            let file_id = from_proto::file_id(&world, &text_document.uri)?;
-            let line_index = world.analysis().file_line_index(file_id)?;
-            let uri = text_document.uri;
-            let path = uri.to_file_path().map_err(|()| format!("invalid uri: {}", uri))?;
-            state.vfs.write().change_file_overlay(&path, |old_text| {
-                apply_document_changes(old_text, Cow::Borrowed(&line_index), content_changes);
-            });
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidSaveTextDocument>(not) {
-        Ok(_params) => {
-            if let Some(flycheck) = &state.flycheck {
-                flycheck.update();
-            }
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidCloseTextDocument>(not) {
-        Ok(params) => {
-            let uri = params.text_document.uri;
-            let path = uri.to_file_path().map_err(|()| format!("invalid uri: {}", uri))?;
-            if let Some(file_id) = state.vfs.write().remove_file_overlay(path.as_path()) {
-                loop_state.subscriptions.remove_sub(FileId(file_id.0));
+        while let Some(event) = self.next_event(&inbox) {
+            if let Event::Lsp(lsp_server::Message::Notification(not)) = &event {
+                if not.method == lsp_types::notification::Exit::METHOD {
+                    return Ok(());
+                }
             }
-            let params =
-                lsp_types::PublishDiagnosticsParams { uri, diagnostics: Vec::new(), version: None };
-            let not = notification_new::<lsp_types::notification::PublishDiagnostics>(params);
-            msg_sender.send(not.into()).unwrap();
-            return Ok(());
+            self.handle_event(event)?
         }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidChangeConfiguration>(not) {
-        Ok(_) => {
-            // As stated in https://github.com/microsoft/language-server-protocol/issues/676,
-            // this notification's parameters should be ignored and the actual config queried separately.
-            let request_id = loop_state.next_request_id();
-            let request = request_new::<lsp_types::request::WorkspaceConfiguration>(
-                request_id.clone(),
-                lsp_types::ConfigurationParams {
-                    items: vec![lsp_types::ConfigurationItem {
-                        scope_uri: None,
-                        section: Some("rust-analyzer".to_string()),
-                    }],
-                },
-            );
-            msg_sender.send(request.into())?;
-            loop_state.configuration_request_id = Some(request_id);
 
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    let not = match notification_cast::<lsp_types::notification::DidChangeWatchedFiles>(not) {
-        Ok(params) => {
-            let mut vfs = state.vfs.write();
-            for change in params.changes {
-                let uri = change.uri;
-                let path = uri.to_file_path().map_err(|()| format!("invalid uri: {}", uri))?;
-                vfs.notify_changed(path)
-            }
-            return Ok(());
-        }
-        Err(not) => not,
-    };
-    if not.method.starts_with("$/") {
-        return Ok(());
+        Err("client exited without proper shutdown sequence")?
     }
-    log::error!("unhandled notification: {:?}", not);
-    Ok(())
-}
-
-fn apply_document_changes(
-    old_text: &mut String,
-    mut line_index: Cow<'_, LineIndex>,
-    content_changes: Vec<TextDocumentContentChangeEvent>,
-) {
-    // Remove when https://github.com/rust-analyzer/rust-analyzer/issues/4263 is fixed.
-    let backup_text = old_text.clone();
-    let backup_changes = content_changes.clone();
 
-    // The changes we got must be applied sequentially, but can cross lines so we
-    // have to keep our line index updated.
-    // Some clients (e.g. Code) sort the ranges in reverse. As an optimization, we
-    // remember the last valid line in the index and only rebuild it if needed.
-    enum IndexValid {
-        All,
-        UpToLineExclusive(u64),
-    }
+    fn handle_event(&mut self, event: Event) -> Result<()> {
+        let loop_start = Instant::now();
+        // NOTE: don't count blocking select! call as a loop-turn time
+        let _p = profile("GlobalState::handle_event");
 
-    impl IndexValid {
-        fn covers(&self, line: u64) -> bool {
-            match *self {
-                IndexValid::UpToLineExclusive(to) => to > line,
-                _ => true,
-            }
+        log::info!("handle_event({:?})", event);
+        let queue_count = self.task_pool.handle.len();
+        if queue_count > 0 {
+            log::info!("queued count = {}", queue_count);
         }
-    }
 
-    let mut index_valid = IndexValid::All;
-    for change in content_changes {
-        match change.range {
-            Some(range) => {
-                if !index_valid.covers(range.end.line) {
-                    line_index = Cow::Owned(LineIndex::new(&old_text));
+        let prev_status = self.status;
+        match event {
+            Event::Lsp(msg) => match msg {
+                lsp_server::Message::Request(req) => self.on_request(loop_start, req)?,
+                lsp_server::Message::Notification(not) => {
+                    self.on_notification(not)?;
                 }
-                index_valid = IndexValid::UpToLineExclusive(range.start.line);
-                let range = from_proto::text_range(&line_index, range);
-                let mut text = old_text.to_owned();
-                match std::panic::catch_unwind(move || {
-                    text.replace_range(Range::<usize>::from(range), &change.text);
-                    text
-                }) {
-                    Ok(t) => *old_text = t,
-                    Err(e) => {
-                        eprintln!("Bug in incremental text synchronization. Please report the following output on https://github.com/rust-analyzer/rust-analyzer/issues/4263");
-                        dbg!(&backup_text);
-                        dbg!(&backup_changes);
-                        std::panic::resume_unwind(e);
+                lsp_server::Message::Response(resp) => self.complete_request(resp),
+            },
+            Event::Task(task) => {
+                match task {
+                    Task::Response(response) => self.respond(response),
+                    Task::Diagnostics(diagnostics_per_file) => {
+                        for (file_id, diagnostics) in diagnostics_per_file {
+                            self.diagnostics.set_native_diagnostics(file_id, diagnostics)
+                        }
                     }
+                    Task::Workspaces(workspaces) => self.switch_workspaces(workspaces),
+                    Task::Unit => (),
                 }
+                self.analysis_host.maybe_collect_garbage();
             }
-            None => {
-                *old_text = change.text;
-                index_valid = IndexValid::UpToLineExclusive(0);
-            }
-        }
-    }
-}
-
-fn on_check_task(
-    task: CheckTask,
-    world_state: &mut WorldState,
-    task_sender: &Sender<Task>,
-) -> Result<()> {
-    match task {
-        CheckTask::ClearDiagnostics => {
-            task_sender.send(Task::Diagnostic(DiagnosticTask::ClearCheck))?;
-        }
-
-        CheckTask::AddDiagnostic { workspace_root, diagnostic } => {
-            let diagnostics = crate::diagnostics::to_proto::map_rust_diagnostic_to_lsp(
-                &diagnostic,
-                &workspace_root,
-            );
-            for diag in diagnostics {
-                let path = diag
-                    .location
-                    .uri
-                    .to_file_path()
-                    .map_err(|()| format!("invalid uri: {}", diag.location.uri))?;
-                let file_id = match world_state.vfs.read().path2file(&path) {
-                    Some(file) => FileId(file.0),
-                    None => {
-                        log::error!(
-                            "File with cargo diagnostic not found in VFS: {}",
-                            path.display()
-                        );
-                        return Ok(());
-                    }
-                };
-
-                task_sender.send(Task::Diagnostic(DiagnosticTask::AddCheck(
-                    file_id,
-                    diag.diagnostic,
-                    diag.fixes.into_iter().map(|it| it.into()).collect(),
-                )))?;
-            }
-        }
-
-        CheckTask::Status(status) => {
-            if world_state.config.client_caps.work_done_progress {
-                let progress = match status {
-                    Status::Being => {
-                        lsp_types::WorkDoneProgress::Begin(lsp_types::WorkDoneProgressBegin {
-                            title: "Running `cargo check`".to_string(),
-                            cancellable: Some(false),
-                            message: None,
-                            percentage: None,
-                        })
-                    }
-                    Status::Progress(target) => {
-                        lsp_types::WorkDoneProgress::Report(lsp_types::WorkDoneProgressReport {
-                            cancellable: Some(false),
-                            message: Some(target),
-                            percentage: None,
-                        })
+            Event::Vfs(mut task) => {
+                let _p = profile("GlobalState::handle_event/vfs");
+                loop {
+                    match task {
+                        vfs::loader::Message::Loaded { files } => {
+                            let vfs = &mut self.vfs.write().0;
+                            for (path, contents) in files {
+                                let path = VfsPath::from(path);
+                                if !self.mem_docs.contains(&path) {
+                                    vfs.set_file_contents(path, contents)
+                                }
+                            }
+                        }
+                        vfs::loader::Message::Progress { n_total, n_done } => {
+                            if n_total == 0 {
+                                self.transition(Status::Invalid);
+                            } else {
+                                let state = if n_done == 0 {
+                                    self.transition(Status::Loading);
+                                    Progress::Begin
+                                } else if n_done < n_total {
+                                    Progress::Report
+                                } else {
+                                    assert_eq!(n_done, n_total);
+                                    self.transition(Status::Ready);
+                                    Progress::End
+                                };
+                                self.report_progress(
+                                    "roots scanned",
+                                    state,
+                                    Some(format!("{}/{}", n_done, n_total)),
+                                    Some(Progress::percentage(n_done, n_total)),
+                                )
+                            }
+                        }
                     }
-                    Status::End => {
-                        lsp_types::WorkDoneProgress::End(lsp_types::WorkDoneProgressEnd {
-                            message: None,
-                        })
+                    // Coalesce many VFS event into a single loop turn
+                    task = match self.loader.receiver.try_recv() {
+                        Ok(task) => task,
+                        Err(_) => break,
                     }
-                };
-
-                let params = lsp_types::ProgressParams {
-                    token: lsp_types::ProgressToken::String(
-                        "rustAnalyzer/cargoWatcher".to_string(),
-                    ),
-                    value: lsp_types::ProgressParamsValue::WorkDone(progress),
-                };
-                let not = notification_new::<lsp_types::notification::Progress>(params);
-                task_sender.send(Task::Notify(not)).unwrap();
+                }
             }
-        }
-    };
+            Event::Flycheck(task) => match task {
+                flycheck::Message::AddDiagnostic { workspace_root, diagnostic } => {
+                    let diagnostics = crate::diagnostics::to_proto::map_rust_diagnostic_to_lsp(
+                        &self.config.diagnostics,
+                        &diagnostic,
+                        &workspace_root,
+                    );
+                    for diag in diagnostics {
+                        match url_to_file_id(&self.vfs.read().0, &diag.url) {
+                            Ok(file_id) => self.diagnostics.add_check_diagnostic(
+                                file_id,
+                                diag.diagnostic,
+                                diag.fixes,
+                            ),
+                            Err(err) => {
+                                log::error!("File with cargo diagnostic not found in VFS: {}", err);
+                            }
+                        };
+                    }
+                }
 
-    Ok(())
-}
+                flycheck::Message::Progress(status) => {
+                    let (state, message) = match status {
+                        flycheck::Progress::DidStart => {
+                            self.diagnostics.clear_check();
+                            (Progress::Begin, None)
+                        }
+                        flycheck::Progress::DidCheckCrate(target) => {
+                            (Progress::Report, Some(target))
+                        }
+                        flycheck::Progress::DidCancel => (Progress::End, None),
+                        flycheck::Progress::DidFinish(result) => {
+                            if let Err(err) = result {
+                                log::error!("cargo check failed: {}", err)
+                            }
+                            (Progress::End, None)
+                        }
+                    };
 
-fn on_diagnostic_task(task: DiagnosticTask, msg_sender: &Sender<Message>, state: &mut WorldState) {
-    let subscriptions = state.diagnostics.handle_task(task);
+                    self.report_progress("cargo check", state, message, None);
+                }
+            },
+        }
 
-    for file_id in subscriptions {
-        let path = state.vfs.read().file2path(VfsFile(file_id.0));
-        let uri = match url_from_path_with_drive_lowercasing(&path) {
-            Ok(uri) => uri,
-            Err(err) => {
-                log::error!("Couldn't convert path to url ({}): {}", err, path.display());
-                continue;
+        let state_changed = self.process_changes();
+        if prev_status == Status::Loading && self.status == Status::Ready {
+            if let Some(flycheck) = &self.flycheck {
+                flycheck.update();
             }
-        };
-
-        let diagnostics = state.diagnostics.diagnostics_for(file_id).cloned().collect();
-        let params = lsp_types::PublishDiagnosticsParams { uri, diagnostics, version: None };
-        let not = notification_new::<lsp_types::notification::PublishDiagnostics>(params);
-        msg_sender.send(not.into()).unwrap();
-    }
-}
-
-fn send_startup_progress(sender: &Sender<Message>, loop_state: &mut LoopState) {
-    let total: usize = loop_state.roots_total;
-    let prev = loop_state.roots_progress_reported;
-    let progress = loop_state.roots_scanned;
-    loop_state.roots_progress_reported = Some(progress);
-
-    match (prev, loop_state.workspace_loaded) {
-        (None, false) => {
-            let work_done_progress_create = request_new::<lsp_types::request::WorkDoneProgressCreate>(
-                loop_state.next_request_id(),
-                WorkDoneProgressCreateParams {
-                    token: lsp_types::ProgressToken::String("rustAnalyzer/startup".into()),
-                },
-            );
-            sender.send(work_done_progress_create.into()).unwrap();
-            send_startup_progress_notif(
-                sender,
-                WorkDoneProgress::Begin(WorkDoneProgressBegin {
-                    title: "rust-analyzer".into(),
-                    cancellable: None,
-                    message: Some(format!("{}/{} packages", progress, total)),
-                    percentage: Some(100.0 * progress as f64 / total as f64),
-                }),
-            );
         }
-        (Some(prev), false) if progress != prev => send_startup_progress_notif(
-            sender,
-            WorkDoneProgress::Report(WorkDoneProgressReport {
-                cancellable: None,
-                message: Some(format!("{}/{} packages", progress, total)),
-                percentage: Some(100.0 * progress as f64 / total as f64),
-            }),
-        ),
-        (_, true) => send_startup_progress_notif(
-            sender,
-            WorkDoneProgress::End(WorkDoneProgressEnd {
-                message: Some(format!("rust-analyzer loaded, {} packages", progress)),
-            }),
-        ),
-        _ => {}
-    }
 
-    fn send_startup_progress_notif(sender: &Sender<Message>, work_done_progress: WorkDoneProgress) {
-        let notif =
-            notification_new::<lsp_types::notification::Progress>(lsp_types::ProgressParams {
-                token: lsp_types::ProgressToken::String("rustAnalyzer/startup".into()),
-                value: lsp_types::ProgressParamsValue::WorkDone(work_done_progress),
-            });
-        sender.send(notif.into()).unwrap();
-    }
-}
-
-struct PoolDispatcher<'a> {
-    req: Option<Request>,
-    pool: &'a ThreadPool,
-    world: &'a mut WorldState,
-    pending_requests: &'a mut PendingRequests,
-    msg_sender: &'a Sender<Message>,
-    task_sender: &'a Sender<Task>,
-    request_received: Instant,
-}
+        if self.status == Status::Ready && (state_changed || prev_status == Status::Loading) {
+            let subscriptions = self
+                .mem_docs
+                .iter()
+                .map(|path| self.vfs.read().0.file_id(&path).unwrap())
+                .collect::<Vec<_>>();
 
-impl<'a> PoolDispatcher<'a> {
-    /// Dispatches the request onto the current thread
-    fn on_sync<R>(
-        &mut self,
-        f: fn(&mut WorldState, R::Params) -> Result<R::Result>,
-    ) -> Result<&mut Self>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + panic::UnwindSafe + 'static,
-        R::Result: Serialize + 'static,
-    {
-        let (id, params) = match self.parse::<R>() {
-            Some(it) => it,
-            None => {
-                return Ok(self);
-            }
-        };
-        let world = panic::AssertUnwindSafe(&mut *self.world);
-        let task = panic::catch_unwind(move || {
-            let result = f(world.0, params);
-            result_to_task::<R>(id, result)
-        })
-        .map_err(|_| format!("sync task {:?} panicked", R::METHOD))?;
-        on_task(task, self.msg_sender, self.pending_requests, self.world);
-        Ok(self)
-    }
+            self.update_file_notifications_on_threadpool(subscriptions);
+        }
 
-    /// Dispatches the request onto thread pool
-    fn on<R>(&mut self, f: fn(WorldSnapshot, R::Params) -> Result<R::Result>) -> Result<&mut Self>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + Send + 'static,
-        R::Result: Serialize + 'static,
-    {
-        let (id, params) = match self.parse::<R>() {
-            Some(it) => it,
-            None => {
-                return Ok(self);
+        if let Some(diagnostic_changes) = self.diagnostics.take_changes() {
+            for file_id in diagnostic_changes {
+                let url = file_id_to_url(&self.vfs.read().0, file_id);
+                let diagnostics = self.diagnostics.diagnostics_for(file_id).cloned().collect();
+                self.send_notification::<lsp_types::notification::PublishDiagnostics>(
+                    lsp_types::PublishDiagnosticsParams { uri: url, diagnostics, version: None },
+                );
             }
-        };
+        }
 
-        self.pool.execute({
-            let world = self.world.snapshot();
-            let sender = self.task_sender.clone();
-            move || {
-                let result = f(world, params);
-                let task = result_to_task::<R>(id, result);
-                sender.send(task).unwrap();
+        let loop_duration = loop_start.elapsed();
+        if loop_duration > Duration::from_millis(100) {
+            log::warn!("overly long loop turn: {:?}", loop_duration);
+            if env::var("RA_PROFILE").is_ok() {
+                self.show_message(
+                    lsp_types::MessageType::Error,
+                    format!("overly long loop turn: {:?}", loop_duration),
+                )
             }
-        });
-
-        Ok(self)
+        }
+        Ok(())
     }
 
-    fn parse<R>(&mut self) -> Option<(RequestId, R::Params)>
-    where
-        R: lsp_types::request::Request + 'static,
-        R::Params: DeserializeOwned + 'static,
-    {
-        let req = self.req.take()?;
-        let (id, params) = match req.extract::<R::Params>(R::METHOD) {
-            Ok(it) => it,
-            Err(req) => {
-                self.req = Some(req);
-                return None;
-            }
-        };
-        self.pending_requests.start(PendingRequest {
-            id: id.clone(),
-            method: R::METHOD.to_string(),
-            received: self.request_received,
-        });
-        Some((id, params))
+    fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
+        self.register_request(&req, request_received);
+
+        RequestDispatcher { req: Some(req), global_state: self }
+            .on_sync::<lsp_ext::ReloadWorkspace>(|s, ()| Ok(s.fetch_workspaces()))?
+            .on_sync::<lsp_ext::JoinLines>(|s, p| handlers::handle_join_lines(s.snapshot(), p))?
+            .on_sync::<lsp_ext::OnEnter>(|s, p| handlers::handle_on_enter(s.snapshot(), p))?
+            .on_sync::<lsp_types::request::Shutdown>(|_, ()| Ok(()))?
+            .on_sync::<lsp_types::request::SelectionRangeRequest>(|s, p| {
+                handlers::handle_selection_range(s.snapshot(), p)
+            })?
+            .on_sync::<lsp_ext::MatchingBrace>(|s, p| {
+                handlers::handle_matching_brace(s.snapshot(), p)
+            })?
+            .on_sync::<lsp_ext::MemoryUsage>(|s, p| handlers::handle_memory_usage(s, p))?
+            .on::<lsp_ext::AnalyzerStatus>(handlers::handle_analyzer_status)?
+            .on::<lsp_ext::SyntaxTree>(handlers::handle_syntax_tree)?
+            .on::<lsp_ext::ExpandMacro>(handlers::handle_expand_macro)?
+            .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)?
+            .on::<lsp_ext::Runnables>(handlers::handle_runnables)?
+            .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)?
+            .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)?
+            .on::<lsp_ext::ResolveCodeActionRequest>(handlers::handle_resolve_code_action)?
+            .on::<lsp_ext::HoverRequest>(handlers::handle_hover)?
+            .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)?
+            .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)?
+            .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
+            .on::<lsp_types::request::GotoDefinition>(handlers::handle_goto_definition)?
+            .on::<lsp_types::request::GotoImplementation>(handlers::handle_goto_implementation)?
+            .on::<lsp_types::request::GotoTypeDefinition>(handlers::handle_goto_type_definition)?
+            .on::<lsp_types::request::Completion>(handlers::handle_completion)?
+            .on::<lsp_types::request::CodeLensRequest>(handlers::handle_code_lens)?
+            .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)?
+            .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)?
+            .on::<lsp_types::request::SignatureHelpRequest>(handlers::handle_signature_help)?
+            .on::<lsp_types::request::PrepareRenameRequest>(handlers::handle_prepare_rename)?
+            .on::<lsp_types::request::Rename>(handlers::handle_rename)?
+            .on::<lsp_types::request::References>(handlers::handle_references)?
+            .on::<lsp_types::request::Formatting>(handlers::handle_formatting)?
+            .on::<lsp_types::request::DocumentHighlightRequest>(
+                handlers::handle_document_highlight,
+            )?
+            .on::<lsp_types::request::CallHierarchyPrepare>(
+                handlers::handle_call_hierarchy_prepare,
+            )?
+            .on::<lsp_types::request::CallHierarchyIncomingCalls>(
+                handlers::handle_call_hierarchy_incoming,
+            )?
+            .on::<lsp_types::request::CallHierarchyOutgoingCalls>(
+                handlers::handle_call_hierarchy_outgoing,
+            )?
+            .on::<lsp_types::request::SemanticTokensRequest>(handlers::handle_semantic_tokens)?
+            .on::<lsp_types::request::SemanticTokensRangeRequest>(
+                handlers::handle_semantic_tokens_range,
+            )?
+            .on::<lsp_ext::Ssr>(handlers::handle_ssr)?
+            .finish();
+        Ok(())
     }
-
-    fn finish(&mut self) {
-        match self.req.take() {
-            None => (),
-            Some(req) => {
-                log::error!("unknown request: {:?}", req);
-                let resp = Response::new_err(
-                    req.id,
-                    ErrorCode::MethodNotFound as i32,
-                    "unknown request".to_string(),
+    fn on_notification(&mut self, not: Notification) -> Result<()> {
+        NotificationDispatcher { not: Some(not), global_state: self }
+            .on::<lsp_types::notification::Cancel>(|this, params| {
+                let id: lsp_server::RequestId = match params.id {
+                    lsp_types::NumberOrString::Number(id) => id.into(),
+                    lsp_types::NumberOrString::String(id) => id.into(),
+                };
+                this.cancel(id);
+                Ok(())
+            })?
+            .on::<lsp_types::notification::DidOpenTextDocument>(|this, params| {
+                if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
+                    if !this.mem_docs.insert(path.clone()) {
+                        log::error!("duplicate DidOpenTextDocument: {}", path)
+                    }
+                    this.vfs
+                        .write()
+                        .0
+                        .set_file_contents(path, Some(params.text_document.text.into_bytes()));
+                }
+                Ok(())
+            })?
+            .on::<lsp_types::notification::DidChangeTextDocument>(|this, params| {
+                if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
+                    assert!(this.mem_docs.contains(&path));
+                    let vfs = &mut this.vfs.write().0;
+                    let file_id = vfs.file_id(&path).unwrap();
+                    let mut text = String::from_utf8(vfs.file_contents(file_id).to_vec()).unwrap();
+                    apply_document_changes(&mut text, params.content_changes);
+                    vfs.set_file_contents(path, Some(text.into_bytes()))
+                }
+                Ok(())
+            })?
+            .on::<lsp_types::notification::DidCloseTextDocument>(|this, params| {
+                if let Ok(path) = from_proto::vfs_path(&params.text_document.uri) {
+                    if !this.mem_docs.remove(&path) {
+                        log::error!("orphan DidCloseTextDocument: {}", path)
+                    }
+                    if let Some(path) = path.as_path() {
+                        this.loader.handle.invalidate(path.to_path_buf());
+                    }
+                }
+                this.send_notification::<lsp_types::notification::PublishDiagnostics>(
+                    lsp_types::PublishDiagnosticsParams {
+                        uri: params.text_document.uri,
+                        diagnostics: Vec::new(),
+                        version: None,
+                    },
                 );
-                self.msg_sender.send(resp.into()).unwrap();
-            }
-        }
-    }
-}
-
-fn result_to_task<R>(id: RequestId, result: Result<R::Result>) -> Task
-where
-    R: lsp_types::request::Request + 'static,
-    R::Params: DeserializeOwned + 'static,
-    R::Result: Serialize + 'static,
-{
-    let response = match result {
-        Ok(resp) => Response::new_ok(id, &resp),
-        Err(e) => match e.downcast::<LspError>() {
-            Ok(lsp_error) => {
-                if lsp_error.code == LspError::UNKNOWN_FILE {
-                    // Work-around for https://github.com/rust-analyzer/rust-analyzer/issues/1521
-                    Response::new_ok(id, ())
-                } else {
-                    Response::new_err(id, lsp_error.code, lsp_error.message)
+                Ok(())
+            })?
+            .on::<lsp_types::notification::DidSaveTextDocument>(|this, params| {
+                if let Some(flycheck) = &this.flycheck {
+                    flycheck.update();
                 }
-            }
-            Err(e) => {
-                if is_canceled(&e) {
-                    Response::new_err(
-                        id,
-                        ErrorCode::ContentModified as i32,
-                        "content modified".to_string(),
-                    )
-                } else {
-                    Response::new_err(id, ErrorCode::InternalError as i32, e.to_string())
+                if let Ok(abs_path) = from_proto::abs_path(&params.text_document.uri) {
+                    this.maybe_refresh(&[(abs_path, ChangeKind::Modify)]);
                 }
-            }
-        },
-    };
-    Task::Respond(response)
-}
-
-fn update_file_notifications_on_threadpool(
-    pool: &ThreadPool,
-    world: WorldSnapshot,
-    task_sender: Sender<Task>,
-    subscriptions: Vec<FileId>,
-) {
-    log::trace!("updating notifications for {:?}", subscriptions);
-    if world.config.publish_diagnostics {
-        pool.execute(move || {
-            for file_id in subscriptions {
-                match handlers::publish_diagnostics(&world, file_id) {
-                    Err(e) => {
-                        if !is_canceled(&e) {
-                            log::error!("failed to compute diagnostics: {:?}", e);
+                Ok(())
+            })?
+            .on::<lsp_types::notification::DidChangeConfiguration>(|this, _params| {
+                // As stated in https://github.com/microsoft/language-server-protocol/issues/676,
+                // this notification's parameters should be ignored and the actual config queried separately.
+                this.send_request::<lsp_types::request::WorkspaceConfiguration>(
+                    lsp_types::ConfigurationParams {
+                        items: vec![lsp_types::ConfigurationItem {
+                            scope_uri: None,
+                            section: Some("rust-analyzer".to_string()),
+                        }],
+                    },
+                    |this, resp| {
+                        log::debug!("config update response: '{:?}", resp);
+                        let Response { error, result, .. } = resp;
+
+                        match (error, result) {
+                            (Some(err), _) => {
+                                log::error!("failed to fetch the server settings: {:?}", err)
+                            }
+                            (None, Some(mut configs)) => {
+                                if let Some(json) = configs.get_mut(0) {
+                                    let mut config = this.config.clone();
+                                    config.update(json.take());
+                                    this.update_configuration(config);
+                                }
+                            }
+                            (None, None) => log::error!(
+                                "received empty server settings response from the client"
+                            ),
                         }
-                    }
-                    Ok(task) => {
-                        task_sender.send(Task::Diagnostic(task)).unwrap();
+                    },
+                );
+
+                return Ok(());
+            })?
+            .on::<lsp_types::notification::DidChangeWatchedFiles>(|this, params| {
+                for change in params.changes {
+                    if let Ok(path) = from_proto::abs_path(&change.uri) {
+                        this.loader.handle.invalidate(path);
                     }
                 }
-            }
-        })
+                Ok(())
+            })?
+            .finish();
+        Ok(())
     }
-}
-
-pub fn show_message(
-    typ: lsp_types::MessageType,
-    message: impl Into<String>,
-    sender: &Sender<Message>,
-) {
-    let message = message.into();
-    let params = lsp_types::ShowMessageParams { typ, message };
-    let not = notification_new::<lsp_types::notification::ShowMessage>(params);
-    sender.send(not.into()).unwrap();
-}
-
-fn is_canceled(e: &Box<dyn std::error::Error + Send + Sync>) -> bool {
-    e.downcast_ref::<Canceled>().is_some()
-}
-
-fn notification_is<N: lsp_types::notification::Notification>(notification: &Notification) -> bool {
-    notification.method == N::METHOD
-}
-
-fn notification_cast<N>(notification: Notification) -> std::result::Result<N::Params, Notification>
-where
-    N: lsp_types::notification::Notification,
-    N::Params: DeserializeOwned,
-{
-    notification.extract(N::METHOD)
-}
-
-fn notification_new<N>(params: N::Params) -> Notification
-where
-    N: lsp_types::notification::Notification,
-    N::Params: Serialize,
-{
-    Notification::new(N::METHOD.to_string(), params)
-}
-
-fn request_new<R>(id: RequestId, params: R::Params) -> Request
-where
-    R: lsp_types::request::Request,
-    R::Params: Serialize,
-{
-    Request::new(id, R::METHOD.to_string(), params)
-}
-
-#[cfg(test)]
-mod tests {
-    use std::borrow::Cow;
-
-    use lsp_types::{Position, Range, TextDocumentContentChangeEvent};
-    use ra_ide::LineIndex;
-
-    #[test]
-    fn apply_document_changes() {
-        fn run(text: &mut String, changes: Vec<TextDocumentContentChangeEvent>) {
-            let line_index = Cow::Owned(LineIndex::new(&text));
-            super::apply_document_changes(text, line_index, changes);
-        }
-
-        macro_rules! c {
-            [$($sl:expr, $sc:expr; $el:expr, $ec:expr => $text:expr),+] => {
-                vec![$(TextDocumentContentChangeEvent {
-                    range: Some(Range {
-                        start: Position { line: $sl, character: $sc },
-                        end: Position { line: $el, character: $ec },
-                    }),
-                    range_length: None,
-                    text: String::from($text),
-                }),+]
-            };
+    fn update_file_notifications_on_threadpool(&mut self, subscriptions: Vec<FileId>) {
+        log::trace!("updating notifications for {:?}", subscriptions);
+        if self.config.publish_diagnostics {
+            let snapshot = self.snapshot();
+            let subscriptions = subscriptions.clone();
+            self.task_pool.handle.spawn(move || {
+                let diagnostics = subscriptions
+                    .into_iter()
+                    .filter_map(|file_id| {
+                        handlers::publish_diagnostics(&snapshot, file_id)
+                            .map_err(|err| {
+                                if !is_canceled(&*err) {
+                                    log::error!("failed to compute diagnostics: {:?}", err);
+                                }
+                                ()
+                            })
+                            .ok()
+                            .map(|diags| (file_id, diags))
+                    })
+                    .collect::<Vec<_>>();
+                Task::Diagnostics(diagnostics)
+            })
         }
-
-        let mut text = String::new();
-        run(&mut text, vec![]);
-        assert_eq!(text, "");
-        run(
-            &mut text,
-            vec![TextDocumentContentChangeEvent {
-                range: None,
-                range_length: None,
-                text: String::from("the"),
-            }],
-        );
-        assert_eq!(text, "the");
-        run(&mut text, c![0, 3; 0, 3 => " quick"]);
-        assert_eq!(text, "the quick");
-        run(&mut text, c![0, 0; 0, 4 => "", 0, 5; 0, 5 => " foxes"]);
-        assert_eq!(text, "quick foxes");
-        run(&mut text, c![0, 11; 0, 11 => "\ndream"]);
-        assert_eq!(text, "quick foxes\ndream");
-        run(&mut text, c![1, 0; 1, 0 => "have "]);
-        assert_eq!(text, "quick foxes\nhave dream");
-        run(&mut text, c![0, 0; 0, 0 => "the ", 1, 4; 1, 4 => " quiet", 1, 16; 1, 16 => "s\n"]);
-        assert_eq!(text, "the quick foxes\nhave quiet dreams\n");
-        run(&mut text, c![0, 15; 0, 15 => "\n", 2, 17; 2, 17 => "\n"]);
-        assert_eq!(text, "the quick foxes\n\nhave quiet dreams\n\n");
-        run(
-            &mut text,
-            c![1, 0; 1, 0 => "DREAM", 2, 0; 2, 0 => "they ", 3, 0; 3, 0 => "DON'T THEY?"],
-        );
-        assert_eq!(text, "the quick foxes\nDREAM\nthey have quiet dreams\nDON'T THEY?\n");
-        run(&mut text, c![0, 10; 1, 5 => "", 2, 0; 2, 12 => ""]);
-        assert_eq!(text, "the quick \nthey have quiet dreams\n");
-
-        text = String::from("❤️");
-        run(&mut text, c![0, 0; 0, 0 => "a"]);
-        assert_eq!(text, "a❤️");
-
-        text = String::from("a\nb");
-        run(&mut text, c![0, 1; 1, 0 => "\nțc", 0, 1; 1, 1 => "d"]);
-        assert_eq!(text, "adcb");
-
-        text = String::from("a\nb");
-        run(&mut text, c![0, 1; 1, 0 => "ț\nc", 0, 2; 0, 2 => "c"]);
-        assert_eq!(text, "ațc\ncb");
+        self.task_pool.handle.spawn({
+            let subs = subscriptions;
+            let snap = self.snapshot();
+            move || {
+                snap.analysis.prime_caches(subs).unwrap_or_else(|_: Canceled| ());
+                Task::Unit
+            }
+        });
     }
 }
diff --git a/crates/rust-analyzer/src/main_loop/pending_requests.rs b/crates/rust-analyzer/src/main_loop/pending_requests.rs
deleted file mode 100644
index 73b33e419..000000000
--- a/crates/rust-analyzer/src/main_loop/pending_requests.rs
+++ /dev/null
@@ -1,75 +0,0 @@
-//! Data structures that keep track of inflight requests.
-
-use std::time::{Duration, Instant};
-
-use lsp_server::RequestId;
-use rustc_hash::FxHashMap;
-
-#[derive(Debug)]
-pub struct CompletedRequest {
-    pub id: RequestId,
-    pub method: String,
-    pub duration: Duration,
-}
-
-#[derive(Debug)]
-pub(crate) struct PendingRequest {
-    pub(crate) id: RequestId,
-    pub(crate) method: String,
-    pub(crate) received: Instant,
-}
-
-impl From<PendingRequest> for CompletedRequest {
-    fn from(pending: PendingRequest) -> CompletedRequest {
-        CompletedRequest {
-            id: pending.id,
-            method: pending.method,
-            duration: pending.received.elapsed(),
-        }
-    }
-}
-
-#[derive(Debug, Default)]
-pub(crate) struct PendingRequests {
-    map: FxHashMap<RequestId, PendingRequest>,
-}
-
-impl PendingRequests {
-    pub(crate) fn start(&mut self, request: PendingRequest) {
-        let id = request.id.clone();
-        let prev = self.map.insert(id.clone(), request);
-        assert!(prev.is_none(), "duplicate request with id {}", id);
-    }
-    pub(crate) fn cancel(&mut self, id: &RequestId) -> bool {
-        self.map.remove(id).is_some()
-    }
-    pub(crate) fn finish(&mut self, id: &RequestId) -> Option<CompletedRequest> {
-        self.map.remove(id).map(CompletedRequest::from)
-    }
-}
-
-const N_COMPLETED_REQUESTS: usize = 10;
-
-#[derive(Debug, Default)]
-pub struct LatestRequests {
-    // hand-rolling VecDeque here to print things in a nicer way
-    buf: [Option<CompletedRequest>; N_COMPLETED_REQUESTS],
-    idx: usize,
-}
-
-impl LatestRequests {
-    pub(crate) fn record(&mut self, request: CompletedRequest) {
-        // special case: don't track status request itself
-        if request.method == "rust-analyzer/analyzerStatus" {
-            return;
-        }
-        let idx = self.idx;
-        self.buf[idx] = Some(request);
-        self.idx = (idx + 1) % N_COMPLETED_REQUESTS;
-    }
-
-    pub(crate) fn iter(&self) -> impl Iterator<Item = (bool, &CompletedRequest)> {
-        let idx = self.idx;
-        self.buf.iter().enumerate().filter_map(move |(i, req)| Some((i == idx, req.as_ref()?)))
-    }
-}
diff --git a/crates/rust-analyzer/src/main_loop/subscriptions.rs b/crates/rust-analyzer/src/main_loop/subscriptions.rs
deleted file mode 100644
index 2c76418be..000000000
--- a/crates/rust-analyzer/src/main_loop/subscriptions.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-//! Keeps track of file subscriptions -- the set of currently opened files for
-//! which we want to publish diagnostics, syntax highlighting, etc.
-
-use ra_ide::FileId;
-use rustc_hash::FxHashSet;
-
-#[derive(Default, Debug)]
-pub(crate) struct Subscriptions {
-    subs: FxHashSet<FileId>,
-}
-
-impl Subscriptions {
-    pub(crate) fn add_sub(&mut self, file_id: FileId) {
-        self.subs.insert(file_id);
-    }
-    pub(crate) fn remove_sub(&mut self, file_id: FileId) {
-        self.subs.remove(&file_id);
-    }
-    pub(crate) fn subscriptions(&self) -> Vec<FileId> {
-        self.subs.iter().copied().collect()
-    }
-}
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
new file mode 100644
index 000000000..3f4dbdd8c
--- /dev/null
+++ b/crates/rust-analyzer/src/reload.rs
@@ -0,0 +1,324 @@
+//! Project loading & configuration updates
+use std::{mem, sync::Arc};
+
+use flycheck::FlycheckHandle;
+use ra_db::{CrateGraph, SourceRoot, VfsPath};
+use ra_ide::AnalysisChange;
+use ra_prof::profile;
+use ra_project_model::{PackageRoot, ProcMacroClient, ProjectWorkspace};
+use vfs::{file_set::FileSetConfig, AbsPath, AbsPathBuf, ChangeKind};
+
+use crate::{
+    config::{Config, FilesWatcher, LinkedProject},
+    global_state::{GlobalState, Status},
+    lsp_ext,
+    main_loop::Task,
+};
+
+impl GlobalState {
+    pub(crate) fn update_configuration(&mut self, config: Config) {
+        let _p = profile("GlobalState::update_configuration");
+        let old_config = mem::replace(&mut self.config, config);
+        if self.config.lru_capacity != old_config.lru_capacity {
+            self.analysis_host.update_lru_capacity(old_config.lru_capacity);
+        }
+        if self.config.linked_projects != old_config.linked_projects {
+            self.fetch_workspaces()
+        } else if self.config.flycheck != old_config.flycheck {
+            self.reload_flycheck();
+        }
+    }
+    pub(crate) fn maybe_refresh(&mut self, changes: &[(AbsPathBuf, ChangeKind)]) {
+        if !changes.iter().any(|(path, kind)| is_interesting(path, *kind)) {
+            return;
+        }
+        match self.status {
+            Status::Loading | Status::NeedsReload => return,
+            Status::Ready | Status::Invalid => (),
+        }
+        if self.config.cargo_autoreload {
+            self.fetch_workspaces();
+        } else {
+            self.transition(Status::NeedsReload);
+        }
+
+        fn is_interesting(path: &AbsPath, change_kind: ChangeKind) -> bool {
+            const IMPLICIT_TARGET_FILES: &[&str] = &["build.rs", "src/main.rs", "src/lib.rs"];
+            const IMPLICIT_TARGET_DIRS: &[&str] = &["src/bin", "examples", "tests", "benches"];
+
+            if path.ends_with("Cargo.toml") || path.ends_with("Cargo.lock") {
+                return true;
+            }
+            if change_kind == ChangeKind::Modify {
+                return false;
+            }
+            if path.extension().unwrap_or_default() != "rs" {
+                return false;
+            }
+            if IMPLICIT_TARGET_FILES.iter().any(|it| path.ends_with(it)) {
+                return true;
+            }
+            let parent = match path.parent() {
+                Some(it) => it,
+                None => return false,
+            };
+            if IMPLICIT_TARGET_DIRS.iter().any(|it| parent.ends_with(it)) {
+                return true;
+            }
+            if path.ends_with("main.rs") {
+                let grand_parent = match parent.parent() {
+                    Some(it) => it,
+                    None => return false,
+                };
+                if IMPLICIT_TARGET_DIRS.iter().any(|it| grand_parent.ends_with(it)) {
+                    return true;
+                }
+            }
+            false
+        }
+    }
+    pub(crate) fn transition(&mut self, new_status: Status) {
+        self.status = new_status;
+        if self.config.client_caps.status_notification {
+            let lsp_status = match new_status {
+                Status::Loading => lsp_ext::Status::Loading,
+                Status::Ready => lsp_ext::Status::Ready,
+                Status::Invalid => lsp_ext::Status::Invalid,
+                Status::NeedsReload => lsp_ext::Status::NeedsReload,
+            };
+            self.send_notification::<lsp_ext::StatusNotification>(lsp_status);
+        }
+    }
+    pub(crate) fn fetch_workspaces(&mut self) {
+        self.task_pool.handle.spawn({
+            let linked_projects = self.config.linked_projects.clone();
+            let cargo_config = self.config.cargo.clone();
+            let with_sysroot = self.config.with_sysroot.clone();
+            move || {
+                let workspaces = linked_projects
+                    .iter()
+                    .map(|project| match project {
+                        LinkedProject::ProjectManifest(manifest) => {
+                            ra_project_model::ProjectWorkspace::load(
+                                manifest.clone(),
+                                &cargo_config,
+                                with_sysroot,
+                            )
+                        }
+                        LinkedProject::InlineJsonProject(it) => {
+                            Ok(ra_project_model::ProjectWorkspace::Json { project: it.clone() })
+                        }
+                    })
+                    .collect::<Vec<_>>();
+                Task::Workspaces(workspaces)
+            }
+        });
+    }
+    pub(crate) fn switch_workspaces(&mut self, workspaces: Vec<anyhow::Result<ProjectWorkspace>>) {
+        let _p = profile("GlobalState::switch_workspaces");
+        log::info!("reloading projects: {:?}", self.config.linked_projects);
+
+        let mut has_errors = false;
+        let workspaces = workspaces
+            .into_iter()
+            .filter_map(|res| {
+                res.map_err(|err| {
+                    has_errors = true;
+                    log::error!("failed to load workspace: {:#}", err);
+                    if self.workspaces.is_empty() {
+                        self.show_message(
+                            lsp_types::MessageType::Error,
+                            format!("rust-analyzer failed to load workspace: {:#}", err),
+                        );
+                    }
+                })
+                .ok()
+            })
+            .collect::<Vec<_>>();
+
+        if &*self.workspaces == &workspaces {
+            return;
+        }
+
+        if !self.workspaces.is_empty() && has_errors {
+            return;
+        }
+
+        if let FilesWatcher::Client = self.config.files.watcher {
+            let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
+                watchers: workspaces
+                    .iter()
+                    .flat_map(ProjectWorkspace::to_roots)
+                    .filter(PackageRoot::is_member)
+                    .map(|root| format!("{}/**/*.rs", root.path().display()))
+                    .map(|glob_pattern| lsp_types::FileSystemWatcher { glob_pattern, kind: None })
+                    .collect(),
+            };
+            let registration = lsp_types::Registration {
+                id: "workspace/didChangeWatchedFiles".to_string(),
+                method: "workspace/didChangeWatchedFiles".to_string(),
+                register_options: Some(serde_json::to_value(registration_options).unwrap()),
+            };
+            self.send_request::<lsp_types::request::RegisterCapability>(
+                lsp_types::RegistrationParams { registrations: vec![registration] },
+                |_, _| (),
+            );
+        }
+
+        let mut change = AnalysisChange::new();
+
+        let project_folders = ProjectFolders::new(&workspaces);
+
+        self.proc_macro_client = match &self.config.proc_macro_srv {
+            None => ProcMacroClient::dummy(),
+            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
+                Ok(it) => it,
+                Err(err) => {
+                    log::error!(
+                        "Failed to run ra_proc_macro_srv from path {}, error: {:?}",
+                        path.display(),
+                        err
+                    );
+                    ProcMacroClient::dummy()
+                }
+            },
+        };
+
+        let watch = match self.config.files.watcher {
+            FilesWatcher::Client => vec![],
+            FilesWatcher::Notify => project_folders.watch,
+        };
+        self.loader.handle.set_config(vfs::loader::Config { load: project_folders.load, watch });
+
+        // Create crate graph from all the workspaces
+        let crate_graph = {
+            let mut crate_graph = CrateGraph::default();
+            let vfs = &mut self.vfs.write().0;
+            let loader = &mut self.loader;
+            let mut load = |path: &AbsPath| {
+                let contents = loader.handle.load_sync(path);
+                let path = vfs::VfsPath::from(path.to_path_buf());
+                vfs.set_file_contents(path.clone(), contents);
+                vfs.file_id(&path)
+            };
+            for ws in workspaces.iter() {
+                crate_graph.extend(ws.to_crate_graph(
+                    self.config.cargo.target.as_deref(),
+                    &self.proc_macro_client,
+                    &mut load,
+                ));
+            }
+
+            crate_graph
+        };
+        change.set_crate_graph(crate_graph);
+
+        self.source_root_config = project_folders.source_root_config;
+        self.workspaces = Arc::new(workspaces);
+
+        self.analysis_host.apply_change(change);
+        self.process_changes();
+        self.reload_flycheck();
+    }
+
+    fn reload_flycheck(&mut self) {
+        let config = match self.config.flycheck.clone() {
+            Some(it) => it,
+            None => {
+                self.flycheck = None;
+                return;
+            }
+        };
+
+        let sender = self.flycheck_sender.clone();
+        let sender = Box::new(move |msg| sender.send(msg).unwrap());
+        self.flycheck = self
+            .workspaces
+            .iter()
+            // FIXME: Figure out the multi-workspace situation
+            .find_map(|w| match w {
+                ProjectWorkspace::Cargo { cargo, sysroot: _ } => Some(cargo),
+                ProjectWorkspace::Json { .. } => None,
+            })
+            .map(move |cargo| {
+                let cargo_project_root = cargo.workspace_root().to_path_buf();
+                FlycheckHandle::spawn(sender, config.clone(), cargo_project_root.into())
+            })
+    }
+}
+
+#[derive(Default)]
+pub(crate) struct ProjectFolders {
+    pub(crate) load: Vec<vfs::loader::Entry>,
+    pub(crate) watch: Vec<usize>,
+    pub(crate) source_root_config: SourceRootConfig,
+}
+
+impl ProjectFolders {
+    pub(crate) fn new(workspaces: &[ProjectWorkspace]) -> ProjectFolders {
+        let mut res = ProjectFolders::default();
+        let mut fsc = FileSetConfig::builder();
+        let mut local_filesets = vec![];
+
+        for root in workspaces.iter().flat_map(|it| it.to_roots()) {
+            let path = root.path().to_owned();
+
+            let mut file_set_roots: Vec<VfsPath> = vec![];
+
+            let entry = if root.is_member() {
+                vfs::loader::Entry::local_cargo_package(path.to_path_buf())
+            } else {
+                vfs::loader::Entry::cargo_package_dependency(path.to_path_buf())
+            };
+            res.load.push(entry);
+            if root.is_member() {
+                res.watch.push(res.load.len() - 1);
+            }
+
+            if let Some(out_dir) = root.out_dir() {
+                let out_dir = out_dir.to_path_buf();
+                res.load.push(vfs::loader::Entry::rs_files_recursively(out_dir.clone()));
+                if root.is_member() {
+                    res.watch.push(res.load.len() - 1);
+                }
+                file_set_roots.push(out_dir.into());
+            }
+            file_set_roots.push(path.to_path_buf().into());
+
+            if root.is_member() {
+                local_filesets.push(fsc.len());
+            }
+            fsc.add_file_set(file_set_roots)
+        }
+
+        let fsc = fsc.build();
+        res.source_root_config = SourceRootConfig { fsc, local_filesets };
+
+        res
+    }
+}
+
+#[derive(Default, Debug)]
+pub(crate) struct SourceRootConfig {
+    pub(crate) fsc: FileSetConfig,
+    pub(crate) local_filesets: Vec<usize>,
+}
+
+impl SourceRootConfig {
+    pub(crate) fn partition(&self, vfs: &vfs::Vfs) -> Vec<SourceRoot> {
+        let _p = profile("SourceRootConfig::partition");
+        self.fsc
+            .partition(vfs)
+            .into_iter()
+            .enumerate()
+            .map(|(idx, file_set)| {
+                let is_local = self.local_filesets.contains(&idx);
+                if is_local {
+                    SourceRoot::new_local(file_set)
+                } else {
+                    SourceRoot::new_library(file_set)
+                }
+            })
+            .collect()
+    }
+}
diff --git a/crates/rust-analyzer/src/request_metrics.rs b/crates/rust-analyzer/src/request_metrics.rs
new file mode 100644
index 000000000..b1019e2d6
--- /dev/null
+++ b/crates/rust-analyzer/src/request_metrics.rs
@@ -0,0 +1,37 @@
+//! Records stats about requests
+use std::time::Duration;
+
+use lsp_server::RequestId;
+
+#[derive(Debug)]
+pub(crate) struct RequestMetrics {
+    pub(crate) id: RequestId,
+    pub(crate) method: String,
+    pub(crate) duration: Duration,
+}
+
+const N_COMPLETED_REQUESTS: usize = 10;
+
+#[derive(Debug, Default)]
+pub(crate) struct LatestRequests {
+    // hand-rolling VecDeque here to print things in a nicer way
+    buf: [Option<RequestMetrics>; N_COMPLETED_REQUESTS],
+    idx: usize,
+}
+
+impl LatestRequests {
+    pub(crate) fn record(&mut self, request: RequestMetrics) {
+        // special case: don't track status request itself
+        if request.method == "rust-analyzer/analyzerStatus" {
+            return;
+        }
+        let idx = self.idx;
+        self.buf[idx] = Some(request);
+        self.idx = (idx + 1) % N_COMPLETED_REQUESTS;
+    }
+
+    pub(crate) fn iter(&self) -> impl Iterator<Item = (bool, &RequestMetrics)> {
+        let idx = self.idx;
+        self.buf.iter().enumerate().filter_map(move |(i, req)| Some((i == idx, req.as_ref()?)))
+    }
+}
diff --git a/crates/rust-analyzer/src/semantic_tokens.rs b/crates/rust-analyzer/src/semantic_tokens.rs
index 6f125c37c..576bd8adc 100644
--- a/crates/rust-analyzer/src/semantic_tokens.rs
+++ b/crates/rust-analyzer/src/semantic_tokens.rs
@@ -39,12 +39,15 @@ define_semantic_token_types![
     (BOOLEAN, "boolean"),
     (BUILTIN_TYPE, "builtinType"),
     (ENUM_MEMBER, "enumMember"),
+    (ESCAPE_SEQUENCE, "escapeSequence"),
+    (FORMAT_SPECIFIER, "formatSpecifier"),
+    (GENERIC, "generic"),
     (LIFETIME, "lifetime"),
+    (PUNCTUATION, "punctuation"),
     (SELF_KEYWORD, "selfKeyword"),
     (TYPE_ALIAS, "typeAlias"),
     (UNION, "union"),
     (UNRESOLVED_REFERENCE, "unresolvedReference"),
-    (FORMAT_SPECIFIER, "formatSpecifier"),
 ];
 
 macro_rules! define_semantic_token_modifiers {
@@ -67,6 +70,7 @@ macro_rules! define_semantic_token_modifiers {
 define_semantic_token_modifiers![
     (CONSTANT, "constant"),
     (CONTROL_FLOW, "controlFlow"),
+    (INJECTED, "injected"),
     (MUTABLE, "mutable"),
     (UNSAFE, "unsafe"),
     (ATTRIBUTE_MODIFIER, "attribute"),
diff --git a/crates/rust-analyzer/src/thread_pool.rs b/crates/rust-analyzer/src/thread_pool.rs
new file mode 100644
index 000000000..4fa502925
--- /dev/null
+++ b/crates/rust-analyzer/src/thread_pool.rs
@@ -0,0 +1,35 @@
+//! A thin wrapper around `ThreadPool` to make sure that we join all things
+//! properly.
+use crossbeam_channel::Sender;
+
+pub(crate) struct TaskPool<T> {
+    sender: Sender<T>,
+    inner: threadpool::ThreadPool,
+}
+
+impl<T> TaskPool<T> {
+    pub(crate) fn new(sender: Sender<T>) -> TaskPool<T> {
+        TaskPool { sender, inner: threadpool::ThreadPool::default() }
+    }
+
+    pub(crate) fn spawn<F>(&mut self, task: F)
+    where
+        F: FnOnce() -> T + Send + 'static,
+        T: Send + 'static,
+    {
+        self.inner.execute({
+            let sender = self.sender.clone();
+            move || sender.send(task()).unwrap()
+        })
+    }
+
+    pub(crate) fn len(&self) -> usize {
+        self.inner.queued_count()
+    }
+}
+
+impl<T> Drop for TaskPool<T> {
+    fn drop(&mut self) {
+        self.inner.join()
+    }
+}
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 2fbbb4e63..2fcae9ca3 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -1,15 +1,20 @@
 //! Conversion of rust-analyzer specific types to lsp_types equivalents.
+use std::path::{self, Path};
+
+use itertools::Itertools;
 use ra_db::{FileId, FileRange};
 use ra_ide::{
-    Assist, CompletionItem, CompletionItemKind, Documentation, FileSystemEdit, Fold, FoldKind,
-    FunctionSignature, Highlight, HighlightModifier, HighlightTag, HighlightedRange, Indel,
-    InlayHint, InlayKind, InsertTextFormat, LineIndex, NavigationTarget, ReferenceAccess, Severity,
-    SourceChange, SourceFileEdit, TextEdit,
+    Assist, AssistKind, CompletionItem, CompletionItemKind, Documentation, FileSystemEdit, Fold,
+    FoldKind, FunctionSignature, Highlight, HighlightModifier, HighlightTag, HighlightedRange,
+    Indel, InlayHint, InlayKind, InsertTextFormat, LineIndex, Markup, NavigationTarget,
+    ReferenceAccess, ResolvedAssist, Runnable, Severity, SourceChange, SourceFileEdit, TextEdit,
 };
 use ra_syntax::{SyntaxKind, TextRange, TextSize};
-use ra_vfs::LineEndings;
 
-use crate::{lsp_ext, semantic_tokens, world::WorldSnapshot, Result};
+use crate::{
+    cargo_target_spec::CargoTargetSpec, global_state::GlobalStateSnapshot,
+    line_endings::LineEndings, lsp_ext, semantic_tokens, Result,
+};
 
 pub(crate) fn position(line_index: &LineIndex, offset: TextSize) -> lsp_types::Position {
     let line_col = line_index.line_col(offset);
@@ -95,6 +100,7 @@ pub(crate) fn completion_item_kind(
         CompletionItemKind::TypeParam => lsp_types::CompletionItemKind::TypeParameter,
         CompletionItemKind::Macro => lsp_types::CompletionItemKind::Method,
         CompletionItemKind::Attribute => lsp_types::CompletionItemKind::EnumMember,
+        CompletionItemKind::UnresolvedReference => lsp_types::CompletionItemKind::Reference,
     }
 }
 
@@ -290,6 +296,7 @@ fn semantic_token_type_and_modifiers(
         HighlightTag::SelfType => lsp_types::SemanticTokenType::TYPE,
         HighlightTag::Field => lsp_types::SemanticTokenType::PROPERTY,
         HighlightTag::Function => lsp_types::SemanticTokenType::FUNCTION,
+        HighlightTag::Generic => semantic_tokens::GENERIC,
         HighlightTag::Module => lsp_types::SemanticTokenType::NAMESPACE,
         HighlightTag::Constant => {
             mods |= semantic_tokens::CONSTANT;
@@ -302,6 +309,7 @@ fn semantic_token_type_and_modifiers(
         }
         HighlightTag::EnumVariant => semantic_tokens::ENUM_MEMBER,
         HighlightTag::Macro => lsp_types::SemanticTokenType::MACRO,
+        HighlightTag::ValueParam => lsp_types::SemanticTokenType::PARAMETER,
         HighlightTag::Local => lsp_types::SemanticTokenType::VARIABLE,
         HighlightTag::TypeParam => lsp_types::SemanticTokenType::TYPE_PARAMETER,
         HighlightTag::Lifetime => semantic_tokens::LIFETIME,
@@ -318,12 +326,16 @@ fn semantic_token_type_and_modifiers(
         HighlightTag::UnresolvedReference => semantic_tokens::UNRESOLVED_REFERENCE,
         HighlightTag::FormatSpecifier => semantic_tokens::FORMAT_SPECIFIER,
         HighlightTag::Operator => lsp_types::SemanticTokenType::OPERATOR,
+        HighlightTag::EscapeSequence => semantic_tokens::ESCAPE_SEQUENCE,
+        HighlightTag::Punctuation => semantic_tokens::PUNCTUATION,
     };
 
     for modifier in highlight.modifiers.iter() {
         let modifier = match modifier {
             HighlightModifier::Attribute => semantic_tokens::ATTRIBUTE_MODIFIER,
             HighlightModifier::Definition => lsp_types::SemanticTokenModifier::DECLARATION,
+            HighlightModifier::Documentation => lsp_types::SemanticTokenModifier::DOCUMENTATION,
+            HighlightModifier::Injected => semantic_tokens::INJECTED,
             HighlightModifier::ControlFlow => semantic_tokens::CONTROL_FLOW,
             HighlightModifier::Mutable => semantic_tokens::MUTABLE,
             HighlightModifier::Unsafe => semantic_tokens::UNSAFE,
@@ -343,7 +355,7 @@ pub(crate) fn folding_range(
     let kind = match fold.kind {
         FoldKind::Comment => Some(lsp_types::FoldingRangeKind::Comment),
         FoldKind::Imports => Some(lsp_types::FoldingRangeKind::Imports),
-        FoldKind::Mods | FoldKind::Block => None,
+        FoldKind::Mods | FoldKind::Block | FoldKind::ArgList => None,
     };
 
     let range = range(line_index, fold.range);
@@ -382,41 +394,87 @@ pub(crate) fn folding_range(
     }
 }
 
-pub(crate) fn url(world: &WorldSnapshot, file_id: FileId) -> Result<lsp_types::Url> {
-    world.file_id_to_uri(file_id)
+pub(crate) fn url(snap: &GlobalStateSnapshot, file_id: FileId) -> lsp_types::Url {
+    snap.file_id_to_url(file_id)
+}
+
+/// Returns a `Url` object from a given path, will lowercase drive letters if present.
+/// This will only happen when processing windows paths.
+///
+/// When processing non-windows path, this is essentially the same as `Url::from_file_path`.
+pub(crate) fn url_from_abs_path(path: &Path) -> lsp_types::Url {
+    assert!(path.is_absolute());
+    let url = lsp_types::Url::from_file_path(path).unwrap();
+    match path.components().next() {
+        Some(path::Component::Prefix(prefix)) if matches!(prefix.kind(), path::Prefix::Disk(_) | path::Prefix::VerbatimDisk(_)) =>
+        {
+            // Need to lowercase driver letter
+        }
+        _ => return url,
+    }
+
+    let driver_letter_range = {
+        let (scheme, drive_letter, _rest) = match url.as_str().splitn(3, ':').collect_tuple() {
+            Some(it) => it,
+            None => return url,
+        };
+        let start = scheme.len() + ':'.len_utf8();
+        start..(start + drive_letter.len())
+    };
+
+    // Note: lowercasing the `path` itself doesn't help, the `Url::parse`
+    // machinery *also* canonicalizes the drive letter. So, just massage the
+    // string in place.
+    let mut url = url.into_string();
+    url[driver_letter_range].make_ascii_lowercase();
+    lsp_types::Url::parse(&url).unwrap()
 }
 
 pub(crate) fn versioned_text_document_identifier(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     file_id: FileId,
     version: Option<i64>,
-) -> Result<lsp_types::VersionedTextDocumentIdentifier> {
-    let res = lsp_types::VersionedTextDocumentIdentifier { uri: url(world, file_id)?, version };
-    Ok(res)
+) -> lsp_types::VersionedTextDocumentIdentifier {
+    lsp_types::VersionedTextDocumentIdentifier { uri: url(snap, file_id), version }
 }
 
-pub(crate) fn location(world: &WorldSnapshot, frange: FileRange) -> Result<lsp_types::Location> {
-    let url = url(world, frange.file_id)?;
-    let line_index = world.analysis().file_line_index(frange.file_id)?;
+pub(crate) fn location(
+    snap: &GlobalStateSnapshot,
+    frange: FileRange,
+) -> Result<lsp_types::Location> {
+    let url = url(snap, frange.file_id);
+    let line_index = snap.analysis.file_line_index(frange.file_id)?;
     let range = range(&line_index, frange.range);
     let loc = lsp_types::Location::new(url, range);
     Ok(loc)
 }
 
+/// Perefer using `location_link`, if the client has the cap.
+pub(crate) fn location_from_nav(
+    snap: &GlobalStateSnapshot,
+    nav: NavigationTarget,
+) -> Result<lsp_types::Location> {
+    let url = url(snap, nav.file_id());
+    let line_index = snap.analysis.file_line_index(nav.file_id())?;
+    let range = range(&line_index, nav.full_range());
+    let loc = lsp_types::Location::new(url, range);
+    Ok(loc)
+}
+
 pub(crate) fn location_link(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     src: Option<FileRange>,
     target: NavigationTarget,
 ) -> Result<lsp_types::LocationLink> {
     let origin_selection_range = match src {
         Some(src) => {
-            let line_index = world.analysis().file_line_index(src.file_id)?;
+            let line_index = snap.analysis.file_line_index(src.file_id)?;
             let range = range(&line_index, src.range);
             Some(range)
         }
         None => None,
     };
-    let (target_uri, target_range, target_selection_range) = location_info(world, target)?;
+    let (target_uri, target_range, target_selection_range) = location_info(snap, target)?;
     let res = lsp_types::LocationLink {
         origin_selection_range,
         target_uri,
@@ -427,12 +485,12 @@ pub(crate) fn location_link(
 }
 
 fn location_info(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     target: NavigationTarget,
 ) -> Result<(lsp_types::Url, lsp_types::Range, lsp_types::Range)> {
-    let line_index = world.analysis().file_line_index(target.file_id())?;
+    let line_index = snap.analysis.file_line_index(target.file_id())?;
 
-    let target_uri = url(world, target.file_id())?;
+    let target_uri = url(snap, target.file_id());
     let target_range = range(&line_index, target.full_range());
     let target_selection_range =
         target.focus_range().map(|it| range(&line_index, it)).unwrap_or(target_range);
@@ -440,14 +498,14 @@ fn location_info(
 }
 
 pub(crate) fn goto_definition_response(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     src: Option<FileRange>,
     targets: Vec<NavigationTarget>,
 ) -> Result<lsp_types::GotoDefinitionResponse> {
-    if world.config.client_caps.location_link {
+    if snap.config.client_caps.location_link {
         let links = targets
             .into_iter()
-            .map(|nav| location_link(world, src, nav))
+            .map(|nav| location_link(snap, src, nav))
             .collect::<Result<Vec<_>>>()?;
         Ok(links.into())
     } else {
@@ -455,7 +513,7 @@ pub(crate) fn goto_definition_response(
             .into_iter()
             .map(|nav| {
                 location(
-                    world,
+                    snap,
                     FileRange {
                         file_id: nav.file_id(),
                         range: nav.focus_range().unwrap_or(nav.range()),
@@ -468,13 +526,13 @@ pub(crate) fn goto_definition_response(
 }
 
 pub(crate) fn snippet_text_document_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     is_snippet: bool,
     source_file_edit: SourceFileEdit,
 ) -> Result<lsp_ext::SnippetTextDocumentEdit> {
-    let text_document = versioned_text_document_identifier(world, source_file_edit.file_id, None)?;
-    let line_index = world.analysis().file_line_index(source_file_edit.file_id)?;
-    let line_endings = world.file_line_endings(source_file_edit.file_id);
+    let text_document = versioned_text_document_identifier(snap, source_file_edit.file_id, None);
+    let line_index = snap.analysis.file_line_index(source_file_edit.file_id)?;
+    let line_endings = snap.file_line_endings(source_file_edit.file_id);
     let edits = source_file_edit
         .edit
         .into_iter()
@@ -484,34 +542,33 @@ pub(crate) fn snippet_text_document_edit(
 }
 
 pub(crate) fn resource_op(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     file_system_edit: FileSystemEdit,
-) -> Result<lsp_types::ResourceOp> {
-    let res = match file_system_edit {
-        FileSystemEdit::CreateFile { source_root, path } => {
-            let uri = world.path_to_uri(source_root, &path)?;
+) -> lsp_types::ResourceOp {
+    match file_system_edit {
+        FileSystemEdit::CreateFile { anchor, dst } => {
+            let uri = snap.anchored_path(anchor, &dst);
             lsp_types::ResourceOp::Create(lsp_types::CreateFile { uri, options: None })
         }
-        FileSystemEdit::MoveFile { src, dst_source_root, dst_path } => {
-            let old_uri = world.file_id_to_uri(src)?;
-            let new_uri = world.path_to_uri(dst_source_root, &dst_path)?;
+        FileSystemEdit::MoveFile { src, anchor, dst } => {
+            let old_uri = snap.file_id_to_url(src);
+            let new_uri = snap.anchored_path(anchor, &dst);
             lsp_types::ResourceOp::Rename(lsp_types::RenameFile { old_uri, new_uri, options: None })
         }
-    };
-    Ok(res)
+    }
 }
 
 pub(crate) fn snippet_workspace_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     source_change: SourceChange,
 ) -> Result<lsp_ext::SnippetWorkspaceEdit> {
     let mut document_changes: Vec<lsp_ext::SnippetDocumentChangeOperation> = Vec::new();
     for op in source_change.file_system_edits {
-        let op = resource_op(&world, op)?;
+        let op = resource_op(&snap, op);
         document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Op(op));
     }
     for edit in source_change.source_file_edits {
-        let edit = snippet_text_document_edit(&world, source_change.is_snippet, edit)?;
+        let edit = snippet_text_document_edit(&snap, source_change.is_snippet, edit)?;
         document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Edit(edit));
     }
     let workspace_edit =
@@ -520,11 +577,11 @@ pub(crate) fn snippet_workspace_edit(
 }
 
 pub(crate) fn workspace_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     source_change: SourceChange,
 ) -> Result<lsp_types::WorkspaceEdit> {
     assert!(!source_change.is_snippet);
-    snippet_workspace_edit(world, source_change).map(|it| it.into())
+    snippet_workspace_edit(snap, source_change).map(|it| it.into())
 }
 
 impl From<lsp_ext::SnippetWorkspaceEdit> for lsp_types::WorkspaceEdit {
@@ -562,45 +619,110 @@ impl From<lsp_ext::SnippetWorkspaceEdit> for lsp_types::WorkspaceEdit {
     }
 }
 
-pub fn call_hierarchy_item(
-    world: &WorldSnapshot,
+pub(crate) fn call_hierarchy_item(
+    snap: &GlobalStateSnapshot,
     target: NavigationTarget,
 ) -> Result<lsp_types::CallHierarchyItem> {
     let name = target.name().to_string();
     let detail = target.description().map(|it| it.to_string());
     let kind = symbol_kind(target.kind());
-    let (uri, range, selection_range) = location_info(world, target)?;
+    let (uri, range, selection_range) = location_info(snap, target)?;
     Ok(lsp_types::CallHierarchyItem { name, kind, tags: None, detail, uri, range, selection_range })
 }
 
+pub(crate) fn code_action_kind(kind: AssistKind) -> lsp_types::CodeActionKind {
+    match kind {
+        AssistKind::None | AssistKind::Generate => lsp_types::CodeActionKind::EMPTY,
+        AssistKind::QuickFix => lsp_types::CodeActionKind::QUICKFIX,
+        AssistKind::Refactor => lsp_types::CodeActionKind::REFACTOR,
+        AssistKind::RefactorExtract => lsp_types::CodeActionKind::REFACTOR_EXTRACT,
+        AssistKind::RefactorInline => lsp_types::CodeActionKind::REFACTOR_INLINE,
+        AssistKind::RefactorRewrite => lsp_types::CodeActionKind::REFACTOR_REWRITE,
+    }
+}
+
+pub(crate) fn unresolved_code_action(
+    snap: &GlobalStateSnapshot,
+    assist: Assist,
+    index: usize,
+) -> Result<lsp_ext::CodeAction> {
+    let res = lsp_ext::CodeAction {
+        title: assist.label,
+        id: Some(format!("{}:{}", assist.id.0.to_owned(), index.to_string())),
+        group: assist.group.filter(|_| snap.config.client_caps.code_action_group).map(|gr| gr.0),
+        kind: Some(code_action_kind(assist.id.1)),
+        edit: None,
+    };
+    Ok(res)
+}
+
+pub(crate) fn resolved_code_action(
+    snap: &GlobalStateSnapshot,
+    assist: ResolvedAssist,
+) -> Result<lsp_ext::CodeAction> {
+    let change = assist.source_change;
+    unresolved_code_action(snap, assist.assist, 0).and_then(|it| {
+        Ok(lsp_ext::CodeAction {
+            id: None,
+            edit: Some(snippet_workspace_edit(snap, change)?),
+            ..it
+        })
+    })
+}
+
+pub(crate) fn runnable(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    runnable: Runnable,
+) -> Result<lsp_ext::Runnable> {
+    let spec = CargoTargetSpec::for_file(snap, file_id)?;
+    let workspace_root = spec.as_ref().map(|it| it.workspace_root.clone());
+    let target = spec.as_ref().map(|s| s.target.clone());
+    let (cargo_args, executable_args) =
+        CargoTargetSpec::runnable_args(snap, spec, &runnable.kind, &runnable.cfg_exprs)?;
+    let label = runnable.label(target);
+    let location = location_link(snap, None, runnable.nav)?;
+
+    Ok(lsp_ext::Runnable {
+        label,
+        location: Some(location),
+        kind: lsp_ext::RunnableKind::Cargo,
+        args: lsp_ext::CargoRunnable {
+            workspace_root: workspace_root.map(|it| it.into()),
+            cargo_args,
+            executable_args,
+            expect_test: None,
+        },
+    })
+}
+
+pub(crate) fn markup_content(markup: Markup) -> lsp_types::MarkupContent {
+    lsp_types::MarkupContent { kind: lsp_types::MarkupKind::Markdown, value: markup.into() }
+}
+
 #[cfg(test)]
 mod tests {
-    use test_utils::extract_ranges;
+    use ra_ide::Analysis;
 
     use super::*;
 
     #[test]
     fn conv_fold_line_folding_only_fixup() {
-        let text = r#"<fold>mod a;
+        let text = r#"mod a;
 mod b;
-mod c;</fold>
+mod c;
 
-fn main() <fold>{
-    if cond <fold>{
+fn main() {
+    if cond {
         a::do_a();
-    }</fold> else <fold>{
+    } else {
         b::do_b();
-    }</fold>
-}</fold>"#;
-
-        let (ranges, text) = extract_ranges(text, "fold");
-        assert_eq!(ranges.len(), 4);
-        let folds = vec![
-            Fold { range: ranges[0], kind: FoldKind::Mods },
-            Fold { range: ranges[1], kind: FoldKind::Block },
-            Fold { range: ranges[2], kind: FoldKind::Block },
-            Fold { range: ranges[3], kind: FoldKind::Block },
-        ];
+    }
+}"#;
+
+        let (analysis, file_id) = Analysis::from_single_file(text.to_string());
+        let folds = analysis.folding_ranges(file_id).unwrap();
+        assert_eq!(folds.len(), 4);
 
         let line_index = LineIndex::new(&text);
         let converted: Vec<lsp_types::FoldingRange> =
@@ -615,15 +737,19 @@ fn main() <fold>{
             assert_eq!(folding_range.end_character, None);
         }
     }
-}
 
-pub(crate) fn code_action(world: &WorldSnapshot, assist: Assist) -> Result<lsp_ext::CodeAction> {
-    let res = lsp_ext::CodeAction {
-        title: assist.label,
-        group: if world.config.client_caps.code_action_group { assist.group_label } else { None },
-        kind: Some(String::new()),
-        edit: Some(snippet_workspace_edit(world, assist.source_change)?),
-        command: None,
-    };
-    Ok(res)
+    // `Url` is not able to parse windows paths on unix machines.
+    #[test]
+    #[cfg(target_os = "windows")]
+    fn test_lowercase_drive_letter_with_drive() {
+        let url = url_from_abs_path(Path::new("C:\\Test"));
+        assert_eq!(url.to_string(), "file:///c:/Test");
+    }
+
+    #[test]
+    #[cfg(target_os = "windows")]
+    fn test_drive_without_colon_passthrough() {
+        let url = url_from_abs_path(Path::new(r#"\\localhost\C$\my_dir"#));
+        assert_eq!(url.to_string(), "file://localhost/C$/my_dir");
+    }
 }
diff --git a/crates/rust-analyzer/src/vfs_glob.rs b/crates/rust-analyzer/src/vfs_glob.rs
deleted file mode 100644
index ff37a7008..000000000
--- a/crates/rust-analyzer/src/vfs_glob.rs
+++ /dev/null
@@ -1,98 +0,0 @@
-//! Exclusion rules for vfs.
-//!
-//! By default, we include only `.rs` files, and skip some know offenders like
-//! `/target` or `/node_modules` altogether.
-//!
-//! It's also possible to add custom exclusion globs.
-
-use globset::{GlobSet, GlobSetBuilder};
-use ra_vfs::{Filter, RelativePath};
-
-pub use globset::{Glob, GlobBuilder};
-
-const ALWAYS_IGNORED: &[&str] = &["target/**", "**/node_modules/**", "**/.git/**"];
-const IGNORED_FOR_NON_MEMBERS: &[&str] = &["examples/**", "tests/**", "benches/**"];
-
-pub struct RustPackageFilterBuilder {
-    is_member: bool,
-    exclude: GlobSetBuilder,
-}
-
-impl Default for RustPackageFilterBuilder {
-    fn default() -> RustPackageFilterBuilder {
-        RustPackageFilterBuilder { is_member: false, exclude: GlobSetBuilder::new() }
-    }
-}
-
-impl RustPackageFilterBuilder {
-    pub fn set_member(mut self, is_member: bool) -> RustPackageFilterBuilder {
-        self.is_member = is_member;
-        self
-    }
-
-    pub fn exclude(mut self, globs: impl IntoIterator<Item = Glob>) -> RustPackageFilterBuilder {
-        for glob in globs.into_iter() {
-            self.exclude.add(glob);
-        }
-        self
-    }
-
-    pub fn into_vfs_filter(self) -> Box<dyn Filter> {
-        let RustPackageFilterBuilder { is_member, mut exclude } = self;
-        for &glob in ALWAYS_IGNORED {
-            exclude.add(Glob::new(glob).unwrap());
-        }
-        if !is_member {
-            for &glob in IGNORED_FOR_NON_MEMBERS {
-                exclude.add(Glob::new(glob).unwrap());
-            }
-        }
-        Box::new(RustPackageFilter { exclude: exclude.build().unwrap() })
-    }
-}
-
-struct RustPackageFilter {
-    exclude: GlobSet,
-}
-
-impl Filter for RustPackageFilter {
-    fn include_dir(&self, dir_path: &RelativePath) -> bool {
-        !self.exclude.is_match(dir_path.as_str())
-    }
-
-    fn include_file(&self, file_path: &RelativePath) -> bool {
-        file_path.extension() == Some("rs")
-    }
-}
-
-#[test]
-fn test_globs() {
-    let filter = RustPackageFilterBuilder::default().set_member(true).into_vfs_filter();
-
-    assert!(filter.include_dir(RelativePath::new("src/tests")));
-    assert!(filter.include_dir(RelativePath::new("src/target")));
-    assert!(filter.include_dir(RelativePath::new("tests")));
-    assert!(filter.include_dir(RelativePath::new("benches")));
-
-    assert!(!filter.include_dir(RelativePath::new("target")));
-    assert!(!filter.include_dir(RelativePath::new("src/foo/.git")));
-    assert!(!filter.include_dir(RelativePath::new("foo/node_modules")));
-
-    let filter = RustPackageFilterBuilder::default().set_member(false).into_vfs_filter();
-
-    assert!(filter.include_dir(RelativePath::new("src/tests")));
-    assert!(filter.include_dir(RelativePath::new("src/target")));
-
-    assert!(!filter.include_dir(RelativePath::new("target")));
-    assert!(!filter.include_dir(RelativePath::new("src/foo/.git")));
-    assert!(!filter.include_dir(RelativePath::new("foo/node_modules")));
-    assert!(!filter.include_dir(RelativePath::new("tests")));
-    assert!(!filter.include_dir(RelativePath::new("benches")));
-
-    let filter = RustPackageFilterBuilder::default()
-        .set_member(true)
-        .exclude(std::iter::once(Glob::new("src/llvm-project/**").unwrap()))
-        .into_vfs_filter();
-
-    assert!(!filter.include_dir(RelativePath::new("src/llvm-project/clang")));
-}
diff --git a/crates/rust-analyzer/src/world.rs b/crates/rust-analyzer/src/world.rs
deleted file mode 100644
index 367272925..000000000
--- a/crates/rust-analyzer/src/world.rs
+++ /dev/null
@@ -1,343 +0,0 @@
-//! The context or environment in which the language server functions. In our
-//! server implementation this is know as the `WorldState`.
-//!
-//! Each tick provides an immutable snapshot of the state as `WorldSnapshot`.
-
-use std::{
-    path::{Path, PathBuf},
-    sync::Arc,
-};
-
-use crossbeam_channel::{unbounded, Receiver};
-use lsp_types::Url;
-use parking_lot::RwLock;
-use ra_flycheck::{Flycheck, FlycheckConfig};
-use ra_ide::{
-    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, LibraryData, SourceRootId,
-};
-use ra_project_model::{get_rustc_cfg_options, ProcMacroClient, ProjectWorkspace};
-use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
-use relative_path::RelativePathBuf;
-use stdx::format_to;
-
-use crate::{
-    config::Config,
-    diagnostics::{
-        to_proto::url_from_path_with_drive_lowercasing, CheckFixes, DiagnosticCollection,
-    },
-    main_loop::pending_requests::{CompletedRequest, LatestRequests},
-    vfs_glob::{Glob, RustPackageFilterBuilder},
-    LspError, Result,
-};
-use ra_db::ExternSourceId;
-use rustc_hash::{FxHashMap, FxHashSet};
-
-fn create_flycheck(workspaces: &[ProjectWorkspace], config: &FlycheckConfig) -> Option<Flycheck> {
-    // FIXME: Figure out the multi-workspace situation
-    workspaces
-        .iter()
-        .find_map(|w| match w {
-            ProjectWorkspace::Cargo { cargo, .. } => Some(cargo),
-            ProjectWorkspace::Json { .. } => None,
-        })
-        .map(|cargo| {
-            let cargo_project_root = cargo.workspace_root().to_path_buf();
-            Some(Flycheck::new(config.clone(), cargo_project_root))
-        })
-        .unwrap_or_else(|| {
-            log::warn!("Cargo check watching only supported for cargo workspaces, disabling");
-            None
-        })
-}
-
-/// `WorldState` is the primary mutable state of the language server
-///
-/// The most interesting components are `vfs`, which stores a consistent
-/// snapshot of the file systems, and `analysis_host`, which stores our
-/// incremental salsa database.
-#[derive(Debug)]
-pub struct WorldState {
-    pub config: Config,
-    pub roots: Vec<PathBuf>,
-    pub workspaces: Arc<Vec<ProjectWorkspace>>,
-    pub analysis_host: AnalysisHost,
-    pub vfs: Arc<RwLock<Vfs>>,
-    pub task_receiver: Receiver<VfsTask>,
-    pub latest_requests: Arc<RwLock<LatestRequests>>,
-    pub flycheck: Option<Flycheck>,
-    pub diagnostics: DiagnosticCollection,
-    pub proc_macro_client: ProcMacroClient,
-}
-
-/// An immutable snapshot of the world's state at a point in time.
-pub struct WorldSnapshot {
-    pub config: Config,
-    pub workspaces: Arc<Vec<ProjectWorkspace>>,
-    pub analysis: Analysis,
-    pub latest_requests: Arc<RwLock<LatestRequests>>,
-    pub check_fixes: CheckFixes,
-    vfs: Arc<RwLock<Vfs>>,
-}
-
-impl WorldState {
-    pub fn new(
-        folder_roots: Vec<PathBuf>,
-        workspaces: Vec<ProjectWorkspace>,
-        lru_capacity: Option<usize>,
-        exclude_globs: &[Glob],
-        watch: Watch,
-        config: Config,
-    ) -> WorldState {
-        let mut change = AnalysisChange::new();
-
-        let extern_dirs: FxHashSet<_> =
-            workspaces.iter().flat_map(ProjectWorkspace::out_dirs).collect();
-
-        let roots: Vec<_> = {
-            let create_filter = |is_member| {
-                RustPackageFilterBuilder::default()
-                    .set_member(is_member)
-                    .exclude(exclude_globs.iter().cloned())
-                    .into_vfs_filter()
-            };
-            folder_roots
-                .iter()
-                .map(|path| RootEntry::new(path.clone(), create_filter(true)))
-                .chain(workspaces.iter().flat_map(ProjectWorkspace::to_roots).map(|pkg_root| {
-                    RootEntry::new(pkg_root.path().to_owned(), create_filter(pkg_root.is_member()))
-                }))
-                .chain(
-                    extern_dirs
-                        .iter()
-                        .map(|path| RootEntry::new(path.to_owned(), create_filter(false))),
-                )
-                .collect()
-        };
-
-        let (task_sender, task_receiver) = unbounded();
-        let task_sender = Box::new(move |t| task_sender.send(t).unwrap());
-        let (mut vfs, vfs_roots) = Vfs::new(roots, task_sender, watch);
-
-        let mut extern_source_roots = FxHashMap::default();
-        for r in vfs_roots {
-            let vfs_root_path = vfs.root2path(r);
-            let is_local = folder_roots.iter().any(|it| vfs_root_path.starts_with(it));
-            change.add_root(SourceRootId(r.0), is_local);
-            change.set_debug_root_path(SourceRootId(r.0), vfs_root_path.display().to_string());
-
-            // FIXME: add path2root in vfs to simpily this logic
-            if extern_dirs.contains(&vfs_root_path) {
-                extern_source_roots.insert(vfs_root_path, ExternSourceId(r.0));
-            }
-        }
-
-        // FIXME: Read default cfgs from config
-        let default_cfg_options = {
-            let mut opts = get_rustc_cfg_options(config.cargo.target.as_ref());
-            opts.insert_atom("test".into());
-            opts.insert_atom("debug_assertion".into());
-            opts
-        };
-
-        let proc_macro_client = match &config.proc_macro_srv {
-            None => ProcMacroClient::dummy(),
-            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
-                Ok(it) => it,
-                Err(err) => {
-                    log::error!(
-                        "Failed to run ra_proc_macro_srv from path {}, error: {:?}",
-                        path.display(),
-                        err
-                    );
-                    ProcMacroClient::dummy()
-                }
-            },
-        };
-
-        // Create crate graph from all the workspaces
-        let mut crate_graph = CrateGraph::default();
-        let mut load = |path: &Path| {
-            // Some path from metadata will be non canonicalized, e.g. /foo/../bar/lib.rs
-            let path = path.canonicalize().ok()?;
-            let vfs_file = vfs.load(&path);
-            vfs_file.map(|f| FileId(f.0))
-        };
-        for ws in workspaces.iter() {
-            crate_graph.extend(ws.to_crate_graph(
-                &default_cfg_options,
-                &extern_source_roots,
-                &proc_macro_client,
-                &mut load,
-            ));
-        }
-        change.set_crate_graph(crate_graph);
-
-        let flycheck = config.check.as_ref().and_then(|c| create_flycheck(&workspaces, c));
-
-        let mut analysis_host = AnalysisHost::new(lru_capacity);
-        analysis_host.apply_change(change);
-        WorldState {
-            config,
-            roots: folder_roots,
-            workspaces: Arc::new(workspaces),
-            analysis_host,
-            vfs: Arc::new(RwLock::new(vfs)),
-            task_receiver,
-            latest_requests: Default::default(),
-            flycheck,
-            diagnostics: Default::default(),
-            proc_macro_client,
-        }
-    }
-
-    pub fn update_configuration(&mut self, config: Config) {
-        self.analysis_host.update_lru_capacity(config.lru_capacity);
-        if config.check != self.config.check {
-            self.flycheck =
-                config.check.as_ref().and_then(|it| create_flycheck(&self.workspaces, it));
-        }
-
-        self.config = config;
-    }
-
-    /// Returns a vec of libraries
-    /// FIXME: better API here
-    pub fn process_changes(
-        &mut self,
-        roots_scanned: &mut usize,
-    ) -> Option<Vec<(SourceRootId, Vec<(FileId, RelativePathBuf, Arc<String>)>)>> {
-        let changes = self.vfs.write().commit_changes();
-        if changes.is_empty() {
-            return None;
-        }
-        let mut libs = Vec::new();
-        let mut change = AnalysisChange::new();
-        for c in changes {
-            match c {
-                VfsChange::AddRoot { root, files } => {
-                    let root_path = self.vfs.read().root2path(root);
-                    let is_local = self.roots.iter().any(|r| root_path.starts_with(r));
-                    if is_local {
-                        *roots_scanned += 1;
-                        for (file, path, text) in files {
-                            change.add_file(SourceRootId(root.0), FileId(file.0), path, text);
-                        }
-                    } else {
-                        let files = files
-                            .into_iter()
-                            .map(|(vfsfile, path, text)| (FileId(vfsfile.0), path, text))
-                            .collect();
-                        libs.push((SourceRootId(root.0), files));
-                    }
-                }
-                VfsChange::AddFile { root, file, path, text } => {
-                    change.add_file(SourceRootId(root.0), FileId(file.0), path, text);
-                }
-                VfsChange::RemoveFile { root, file, path } => {
-                    change.remove_file(SourceRootId(root.0), FileId(file.0), path)
-                }
-                VfsChange::ChangeFile { file, text } => {
-                    change.change_file(FileId(file.0), text);
-                }
-            }
-        }
-        self.analysis_host.apply_change(change);
-        Some(libs)
-    }
-
-    pub fn add_lib(&mut self, data: LibraryData) {
-        let mut change = AnalysisChange::new();
-        change.add_library(data);
-        self.analysis_host.apply_change(change);
-    }
-
-    pub fn snapshot(&self) -> WorldSnapshot {
-        WorldSnapshot {
-            config: self.config.clone(),
-            workspaces: Arc::clone(&self.workspaces),
-            analysis: self.analysis_host.analysis(),
-            vfs: Arc::clone(&self.vfs),
-            latest_requests: Arc::clone(&self.latest_requests),
-            check_fixes: Arc::clone(&self.diagnostics.check_fixes),
-        }
-    }
-
-    pub fn maybe_collect_garbage(&mut self) {
-        self.analysis_host.maybe_collect_garbage()
-    }
-
-    pub fn collect_garbage(&mut self) {
-        self.analysis_host.collect_garbage()
-    }
-
-    pub fn complete_request(&mut self, request: CompletedRequest) {
-        self.latest_requests.write().record(request)
-    }
-}
-
-impl WorldSnapshot {
-    pub fn analysis(&self) -> &Analysis {
-        &self.analysis
-    }
-
-    pub fn uri_to_file_id(&self, uri: &Url) -> Result<FileId> {
-        let path = uri.to_file_path().map_err(|()| format!("invalid uri: {}", uri))?;
-        let file = self.vfs.read().path2file(&path).ok_or_else(|| {
-            // Show warning as this file is outside current workspace
-            // FIXME: just handle such files, and remove `LspError::UNKNOWN_FILE`.
-            LspError {
-                code: LspError::UNKNOWN_FILE,
-                message: "Rust file outside current workspace is not supported yet.".to_string(),
-            }
-        })?;
-        Ok(FileId(file.0))
-    }
-
-    pub fn file_id_to_uri(&self, id: FileId) -> Result<Url> {
-        let path = self.vfs.read().file2path(VfsFile(id.0));
-        let url = url_from_path_with_drive_lowercasing(path)?;
-
-        Ok(url)
-    }
-
-    pub fn file_id_to_path(&self, id: FileId) -> PathBuf {
-        self.vfs.read().file2path(VfsFile(id.0))
-    }
-
-    pub fn file_line_endings(&self, id: FileId) -> LineEndings {
-        self.vfs.read().file_line_endings(VfsFile(id.0))
-    }
-
-    pub fn path_to_uri(&self, root: SourceRootId, path: &RelativePathBuf) -> Result<Url> {
-        let base = self.vfs.read().root2path(VfsRoot(root.0));
-        let path = path.to_path(base);
-        let url = Url::from_file_path(&path)
-            .map_err(|_| format!("can't convert path to url: {}", path.display()))?;
-        Ok(url)
-    }
-
-    pub fn status(&self) -> String {
-        let mut buf = String::new();
-        if self.workspaces.is_empty() {
-            buf.push_str("no workspaces\n")
-        } else {
-            buf.push_str("workspaces:\n");
-            for w in self.workspaces.iter() {
-                format_to!(buf, "{} packages loaded\n", w.n_packages());
-            }
-        }
-        buf.push_str("\nanalysis:\n");
-        buf.push_str(
-            &self
-                .analysis
-                .status()
-                .unwrap_or_else(|_| "Analysis retrieval was cancelled".to_owned()),
-        );
-        buf
-    }
-
-    pub fn workspace_root_for(&self, file_id: FileId) -> Option<&Path> {
-        let path = self.vfs.read().file2path(VfsFile(file_id.0));
-        self.workspaces.iter().find_map(|ws| ws.workspace_root_for(&path))
-    }
-}
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_clippy_pass_by_ref.snap b/crates/rust-analyzer/test_data/clippy_pass_by_ref.txt
index d7f9ec049..d06517126 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_clippy_pass_by_ref.snap
+++ b/crates/rust-analyzer/test_data/clippy_pass_by_ref.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/compiler/mir/tagset.rs",
-            range: Range {
-                start: Position {
-                    line: 41,
-                    character: 23,
-                },
-                end: Position {
-                    line: 41,
-                    character: 28,
-                },
-            },
-        },
+        url: "file:///test/compiler/mir/tagset.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_handles_macro_location.snap b/crates/rust-analyzer/test_data/handles_macro_location.txt
index a59faf254..f5de2f07f 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_handles_macro_location.snap
+++ b/crates/rust-analyzer/test_data/handles_macro_location.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/src/main.rs",
-            range: Range {
-                start: Position {
-                    line: 1,
-                    character: 4,
-                },
-                end: Position {
-                    line: 1,
-                    character: 26,
-                },
-            },
-        },
+        url: "file:///test/src/main.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_macro_compiler_error.snap b/crates/rust-analyzer/test_data/macro_compiler_error.txt
index 3c78e7f36..f695db73c 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_macro_compiler_error.snap
+++ b/crates/rust-analyzer/test_data/macro_compiler_error.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/crates/ra_hir_def/src/data.rs",
-            range: Range {
-                start: Position {
-                    line: 79,
-                    character: 15,
-                },
-                end: Position {
-                    line: 79,
-                    character: 41,
-                },
-            },
-        },
+        url: "file:///test/crates/ra_hir_def/src/data.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_incompatible_type_for_trait.snap b/crates/rust-analyzer/test_data/rustc_incompatible_type_for_trait.txt
index 46d0c56d2..fc54440be 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_incompatible_type_for_trait.snap
+++ b/crates/rust-analyzer/test_data/rustc_incompatible_type_for_trait.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/compiler/ty/list_iter.rs",
-            range: Range {
-                start: Position {
-                    line: 51,
-                    character: 4,
-                },
-                end: Position {
-                    line: 51,
-                    character: 47,
-                },
-            },
-        },
+        url: "file:///test/compiler/ty/list_iter.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_mismatched_type.snap b/crates/rust-analyzer/test_data/rustc_mismatched_type.txt
index 4182929ba..c269af218 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_mismatched_type.snap
+++ b/crates/rust-analyzer/test_data/rustc_mismatched_type.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/runtime/compiler_support.rs",
-            range: Range {
-                start: Position {
-                    line: 47,
-                    character: 64,
-                },
-                end: Position {
-                    line: 47,
-                    character: 69,
-                },
-            },
-        },
+        url: "file:///test/runtime/compiler_support.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap b/crates/rust-analyzer/test_data/rustc_unused_variable.txt
index 6dd3fcb2e..084632757 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
+++ b/crates/rust-analyzer/test_data/rustc_unused_variable.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/driver/subcommand/repl.rs",
-            range: Range {
-                start: Position {
-                    line: 290,
-                    character: 8,
-                },
-                end: Position {
-                    line: 290,
-                    character: 11,
-                },
-            },
-        },
+        url: "file:///test/driver/subcommand/repl.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
@@ -50,11 +34,13 @@ expression: diag
         fixes: [
             CodeAction {
                 title: "consider prefixing with an underscore",
+                id: None,
                 group: None,
                 kind: Some(
-                    "quickfix",
+                    CodeActionKind(
+                        "quickfix",
+                    ),
                 ),
-                command: None,
                 edit: Some(
                     SnippetWorkspaceEdit {
                         changes: Some(
diff --git a/crates/rust-analyzer/test_data/rustc_unused_variable_as_hint.txt b/crates/rust-analyzer/test_data/rustc_unused_variable_as_hint.txt
new file mode 100644
index 000000000..d637923c5
--- /dev/null
+++ b/crates/rust-analyzer/test_data/rustc_unused_variable_as_hint.txt
@@ -0,0 +1,71 @@
+[
+    MappedRustDiagnostic {
+        url: "file:///test/driver/subcommand/repl.rs",
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 290,
+                    character: 8,
+                },
+                end: Position {
+                    line: 290,
+                    character: 11,
+                },
+            },
+            severity: Some(
+                Hint,
+            ),
+            code: Some(
+                String(
+                    "unused_variables",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "unused variable: `foo`\n#[warn(unused_variables)] on by default",
+            related_information: None,
+            tags: Some(
+                [
+                    Unnecessary,
+                ],
+            ),
+        },
+        fixes: [
+            CodeAction {
+                title: "consider prefixing with an underscore",
+                id: None,
+                group: None,
+                kind: Some(
+                    CodeActionKind(
+                        "quickfix",
+                    ),
+                ),
+                edit: Some(
+                    SnippetWorkspaceEdit {
+                        changes: Some(
+                            {
+                                "file:///test/driver/subcommand/repl.rs": [
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 290,
+                                                character: 8,
+                                            },
+                                            end: Position {
+                                                line: 290,
+                                                character: 11,
+                                            },
+                                        },
+                                        new_text: "_foo",
+                                    },
+                                ],
+                            },
+                        ),
+                        document_changes: None,
+                    },
+                ),
+            },
+        ],
+    },
+]
diff --git a/crates/rust-analyzer/test_data/rustc_unused_variable_as_info.txt b/crates/rust-analyzer/test_data/rustc_unused_variable_as_info.txt
new file mode 100644
index 000000000..6b48f16ed
--- /dev/null
+++ b/crates/rust-analyzer/test_data/rustc_unused_variable_as_info.txt
@@ -0,0 +1,71 @@
+[
+    MappedRustDiagnostic {
+        url: "file:///test/driver/subcommand/repl.rs",
+        diagnostic: Diagnostic {
+            range: Range {
+                start: Position {
+                    line: 290,
+                    character: 8,
+                },
+                end: Position {
+                    line: 290,
+                    character: 11,
+                },
+            },
+            severity: Some(
+                Information,
+            ),
+            code: Some(
+                String(
+                    "unused_variables",
+                ),
+            ),
+            source: Some(
+                "rustc",
+            ),
+            message: "unused variable: `foo`\n#[warn(unused_variables)] on by default",
+            related_information: None,
+            tags: Some(
+                [
+                    Unnecessary,
+                ],
+            ),
+        },
+        fixes: [
+            CodeAction {
+                title: "consider prefixing with an underscore",
+                id: None,
+                group: None,
+                kind: Some(
+                    CodeActionKind(
+                        "quickfix",
+                    ),
+                ),
+                edit: Some(
+                    SnippetWorkspaceEdit {
+                        changes: Some(
+                            {
+                                "file:///test/driver/subcommand/repl.rs": [
+                                    TextEdit {
+                                        range: Range {
+                                            start: Position {
+                                                line: 290,
+                                                character: 8,
+                                            },
+                                            end: Position {
+                                                line: 290,
+                                                character: 11,
+                                            },
+                                        },
+                                        new_text: "_foo",
+                                    },
+                                ],
+                            },
+                        ),
+                        document_changes: None,
+                    },
+                ),
+            },
+        ],
+    },
+]
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_wrong_number_of_parameters.snap b/crates/rust-analyzer/test_data/rustc_wrong_number_of_parameters.txt
index f6ab05004..efe37261d 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_wrong_number_of_parameters.snap
+++ b/crates/rust-analyzer/test_data/rustc_wrong_number_of_parameters.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/compiler/ty/select.rs",
-            range: Range {
-                start: Position {
-                    line: 103,
-                    character: 17,
-                },
-                end: Position {
-                    line: 103,
-                    character: 29,
-                },
-            },
-        },
+        url: "file:///test/compiler/ty/select.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap b/crates/rust-analyzer/test_data/snap_multi_line_fix.txt
index c40cfdcdc..2c4cbea16 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
+++ b/crates/rust-analyzer/test_data/snap_multi_line_fix.txt
@@ -1,22 +1,6 @@
----
-source: crates/rust-analyzer/src/diagnostics/to_proto.rs
-expression: diag
----
 [
     MappedRustDiagnostic {
-        location: Location {
-            uri: "file:///test/src/main.rs",
-            range: Range {
-                start: Position {
-                    line: 3,
-                    character: 4,
-                },
-                end: Position {
-                    line: 3,
-                    character: 5,
-                },
-            },
-        },
+        url: "file:///test/src/main.rs",
         diagnostic: Diagnostic {
             range: Range {
                 start: Position {
@@ -65,11 +49,13 @@ expression: diag
         fixes: [
             CodeAction {
                 title: "return the expression directly",
+                id: None,
                 group: None,
                 kind: Some(
-                    "quickfix",
+                    CodeActionKind(
+                        "quickfix",
+                    ),
                 ),
-                command: None,
                 edit: Some(
                     SnippetWorkspaceEdit {
                         changes: Some(
diff --git a/crates/rust-analyzer/tests/heavy_tests/main.rs b/crates/rust-analyzer/tests/heavy_tests/main.rs
index 405ddb362..7b908d30c 100644
--- a/crates/rust-analyzer/tests/heavy_tests/main.rs
+++ b/crates/rust-analyzer/tests/heavy_tests/main.rs
@@ -4,9 +4,7 @@ use std::{collections::HashMap, path::PathBuf, time::Instant};
 
 use lsp_types::{
     notification::DidOpenTextDocument,
-    request::{
-        CodeActionRequest, Completion, Formatting, GotoDefinition, GotoTypeDefinition, HoverRequest,
-    },
+    request::{CodeActionRequest, Completion, Formatting, GotoTypeDefinition, HoverRequest},
     CodeActionContext, CodeActionParams, CompletionParams, DidOpenTextDocumentParams,
     DocumentFormattingParams, FormattingOptions, GotoDefinitionParams, HoverParams,
     PartialResultParams, Position, Range, TextDocumentItem, TextDocumentPositionParams,
@@ -31,12 +29,12 @@ fn completes_items_from_standard_library() {
     let project_start = Instant::now();
     let server = Project::with_fixture(
         r#"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- src/lib.rs
+//- /src/lib.rs
 use std::collections::Spam;
 "#,
     )
@@ -54,81 +52,35 @@ use std::collections::Spam;
         partial_result_params: PartialResultParams::default(),
         work_done_progress_params: WorkDoneProgressParams::default(),
     });
-    assert!(format!("{}", res).contains("HashMap"));
+    assert!(res.to_string().contains("HashMap"));
     eprintln!("completion took {:?}", completion_start.elapsed());
 }
 
 #[test]
-fn test_runnables_no_project() {
-    if skip_slow_tests() {
-        return;
-    }
-
-    let server = project(
-        r"
-//- lib.rs
-#[test]
-fn foo() {
-}
-",
-    );
-    server.wait_until_workspace_is_loaded();
-    server.request::<Runnables>(
-        RunnablesParams { text_document: server.doc_id("lib.rs"), position: None },
-        json!([
-          {
-            "args": [ "test" ],
-            "extraArgs": [ "foo", "--nocapture" ],
-            "bin": "cargo",
-            "env": { "RUST_BACKTRACE": "short" },
-            "cwd": null,
-            "label": "test foo",
-            "range": {
-              "end": { "character": 1, "line": 2 },
-              "start": { "character": 0, "line": 0 }
-            }
-          },
-          {
-            "args": ["check", "--workspace"],
-            "extraArgs": [],
-            "bin": "cargo",
-            "env": {},
-            "cwd": null,
-            "label": "cargo check --workspace",
-            "range": {
-              "end": { "character": 0, "line": 0 },
-              "start": { "character": 0, "line": 0 }
-            }
-          }
-        ]),
-    );
-}
-
-#[test]
 fn test_runnables_project() {
     if skip_slow_tests() {
         return;
     }
 
     let code = r#"
-//- foo/Cargo.toml
+//- /foo/Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- foo/src/lib.rs
+//- /foo/src/lib.rs
 pub fn foo() {}
 
-//- foo/tests/spam.rs
+//- /foo/tests/spam.rs
 #[test]
 fn test_eggs() {}
 
-//- bar/Cargo.toml
+//- /bar/Cargo.toml
 [package]
 name = "bar"
 version = "0.0.0"
 
-//- bar/src/main.rs
+//- /bar/src/main.rs
 fn main() {}
 "#;
 
@@ -138,42 +90,44 @@ fn main() {}
     server.request::<Runnables>(
         RunnablesParams { text_document: server.doc_id("foo/tests/spam.rs"), position: None },
         json!([
-            {
-              "args": [ "test", "--package", "foo", "--test", "spam" ],
-              "extraArgs": [ "test_eggs", "--exact", "--nocapture" ],
-              "bin": "cargo",
-              "env": { "RUST_BACKTRACE": "short" },
-              "label": "test test_eggs",
-              "range": {
-                "end": { "character": 17, "line": 1 },
-                "start": { "character": 0, "line": 0 }
-              },
-              "cwd": server.path().join("foo")
+          {
+            "args": {
+              "cargoArgs": ["test", "--package", "foo", "--test", "spam"],
+              "executableArgs": ["test_eggs", "--exact", "--nocapture"],
+              "workspaceRoot": server.path().join("foo")
             },
-            {
-              "args": [ "check", "--package", "foo" ],
-              "extraArgs": [],
-              "bin": "cargo",
-              "env": {},
-              "label": "cargo check -p foo",
-              "range": {
-                "end": { "character": 0, "line": 0 },
+            "kind": "cargo",
+            "label": "test test_eggs",
+            "location": {
+              "targetRange": {
+                "end": { "character": 17, "line": 1 },
                 "start": { "character": 0, "line": 0 }
               },
-              "cwd": server.path().join("foo")
-            },
-            {
-              "args": [ "test", "--package", "foo" ],
-              "extraArgs": [],
-              "bin": "cargo",
-              "env": {},
-              "label": "cargo test -p foo",
-              "range": {
-                "end": { "character": 0, "line": 0 },
-                "start": { "character": 0, "line": 0 }
+              "targetSelectionRange": {
+                "end": { "character": 12, "line": 1 },
+                "start": { "character": 3, "line": 1 }
               },
-              "cwd": server.path().join("foo")
+              "targetUri": "file:///[..]/tests/spam.rs"
             }
+          },
+          {
+            "args": {
+              "cargoArgs": ["check", "--package", "foo"],
+              "executableArgs": [],
+              "workspaceRoot": server.path().join("foo")
+            },
+            "kind": "cargo",
+            "label": "cargo check -p foo"
+          },
+          {
+            "args": {
+              "cargoArgs": ["test", "--package", "foo"],
+              "executableArgs": [],
+              "workspaceRoot": server.path().join("foo")
+            },
+            "kind": "cargo",
+            "label": "cargo test -p foo"
+          }
         ]),
     );
 }
@@ -186,12 +140,12 @@ fn test_format_document() {
 
     let server = project(
         r#"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- src/lib.rs
+//- /src/lib.rs
 mod bar;
 
 fn main() {
@@ -224,14 +178,8 @@ fn main() {}
 pub use std::collections::HashMap;
 "#,
                 "range": {
-                    "end": {
-                        "character": 0,
-                        "line": 7
-                    },
-                    "start": {
-                        "character": 0,
-                        "line": 0
-                    }
+                    "end": { "character": 0, "line": 6 },
+                    "start": { "character": 0, "line": 0 }
                 }
             }
         ]),
@@ -246,13 +194,13 @@ fn test_format_document_2018() {
 
     let server = project(
         r#"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 edition = "2018"
 
-//- src/lib.rs
+//- /src/lib.rs
 mod bar;
 
 async fn test() {
@@ -290,14 +238,8 @@ fn main() {}
 pub use std::collections::HashMap;
 "#,
                 "range": {
-                    "end": {
-                        "character": 0,
-                        "line": 10
-                    },
-                    "start": {
-                        "character": 0,
-                        "line": 0
-                    }
+                    "end": { "character": 0, "line": 9 },
+                    "start": { "character": 0, "line": 0 }
                 }
             }
         ]),
@@ -312,12 +254,12 @@ fn test_missing_module_code_action() {
 
     let server = project(
         r#"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- src/lib.rs
+//- /src/lib.rs
 mod bar;
 
 fn main() {}
@@ -342,6 +284,7 @@ fn main() {}
                 }
               ]
             },
+            "kind": "quickfix",
             "title": "Create module"
         }]),
     );
@@ -374,17 +317,16 @@ fn test_missing_module_code_action_in_json_project() {
             "root_module": path.join("src/lib.rs"),
             "deps": [],
             "edition": "2015",
-            "atom_cfgs": [],
-            "key_value_cfgs": {}
+            "cfg": [ "cfg_atom_1", "feature=cfg_1"],
         } ]
     });
 
     let code = format!(
         r#"
-//- rust-project.json
+//- /rust-project.json
 {PROJECT}
 
-//- src/lib.rs
+//- /src/lib.rs
 mod bar;
 
 fn main() {{}}
@@ -413,6 +355,7 @@ fn main() {{}}
                 }
               ]
             },
+            "kind": "quickfix",
             "title": "Create module"
         }]),
     );
@@ -436,15 +379,15 @@ fn diagnostics_dont_block_typing() {
     }
 
     let librs: String = (0..10).map(|i| format!("mod m{};", i)).collect();
-    let libs: String = (0..10).map(|i| format!("//- src/m{}.rs\nfn foo() {{}}\n\n", i)).collect();
+    let libs: String = (0..10).map(|i| format!("//- /src/m{}.rs\nfn foo() {{}}\n\n", i)).collect();
     let server = Project::with_fixture(&format!(
         r#"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- src/lib.rs
+//- /src/lib.rs
 {}
 
 {}
@@ -494,16 +437,17 @@ fn preserves_dos_line_endings() {
 
     let server = Project::with_fixture(
         &"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = \"foo\"
 version = \"0.0.0\"
 
-//- src/main.rs
+//- /src/main.rs
 /// Some Docs\r\nfn main() {}
 ",
     )
     .server();
+    server.wait_until_workspace_is_loaded();
 
     server.request::<OnEnter>(
         TextDocumentPositionParams {
@@ -529,12 +473,12 @@ fn out_dirs_check() {
 
     let server = Project::with_fixture(
         r###"
-//- Cargo.toml
+//- /Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
 
-//- build.rs
+//- /build.rs
 use std::{env, fs, path::Path};
 
 fn main() {
@@ -549,7 +493,12 @@ fn main() {
     println!("cargo:rustc-cfg=featlike=\"set\"");
     println!("cargo:rerun-if-changed=build.rs");
 }
-//- src/main.rs
+//- /src/main.rs
+#[rustc_builtin_macro] macro_rules! include {}
+#[rustc_builtin_macro] macro_rules! include_str {}
+#[rustc_builtin_macro] macro_rules! concat {}
+#[rustc_builtin_macro] macro_rules! env {}
+
 include!(concat!(env!("OUT_DIR"), "/hello.rs"));
 
 #[cfg(atom_cfg)]
@@ -564,10 +513,9 @@ struct B;
 fn main() {
     let va = A;
     let vb = B;
-    message();
+    let should_be_str = message();
+    let another_str = include_str!("main.rs");
 }
-
-fn main() { message(); }
 "###,
     )
     .with_config(|config| {
@@ -575,54 +523,43 @@ fn main() { message(); }
     })
     .server();
     server.wait_until_workspace_is_loaded();
-    let res = server.send_request::<GotoDefinition>(GotoDefinitionParams {
+    let res = server.send_request::<HoverRequest>(HoverParams {
+        text_document_position_params: TextDocumentPositionParams::new(
+            server.doc_id("src/main.rs"),
+            Position::new(19, 10),
+        ),
+        work_done_progress_params: Default::default(),
+    });
+    assert!(res.to_string().contains("&str"));
+    let res = server.send_request::<HoverRequest>(HoverParams {
         text_document_position_params: TextDocumentPositionParams::new(
             server.doc_id("src/main.rs"),
-            Position::new(14, 8),
+            Position::new(20, 10),
         ),
         work_done_progress_params: Default::default(),
-        partial_result_params: Default::default(),
     });
-    assert!(format!("{}", res).contains("hello.rs"));
+    assert!(res.to_string().contains("&str"));
     server.request::<GotoTypeDefinition>(
         GotoDefinitionParams {
             text_document_position_params: TextDocumentPositionParams::new(
                 server.doc_id("src/main.rs"),
-                Position::new(12, 9),
+                Position::new(17, 9),
             ),
             work_done_progress_params: Default::default(),
             partial_result_params: Default::default(),
         },
         json!([{
             "originSelectionRange": {
-                "end": {
-                    "character": 10,
-                    "line": 12
-                },
-                "start": {
-                    "character": 8,
-                    "line": 12
-                }
+                "end": { "character": 10, "line": 17 },
+                "start": { "character": 8, "line": 17 }
             },
             "targetRange": {
-                "end": {
-                    "character": 9,
-                    "line": 3
-                },
-                "start": {
-                    "character": 0,
-                    "line": 2
-                }
+                "end": { "character": 9, "line": 8 },
+                "start": { "character": 0, "line": 7 }
             },
             "targetSelectionRange": {
-                "end": {
-                    "character": 8,
-                    "line": 3
-                },
-                "start": {
-                    "character": 7,
-                    "line": 3
-                }
+                "end": { "character": 8, "line": 8 },
+                "start": { "character": 7, "line": 8 }
             },
             "targetUri": "file:///[..]src/main.rs"
         }]),
@@ -631,41 +568,23 @@ fn main() { message(); }
         GotoDefinitionParams {
             text_document_position_params: TextDocumentPositionParams::new(
                 server.doc_id("src/main.rs"),
-                Position::new(13, 9),
+                Position::new(18, 9),
             ),
             work_done_progress_params: Default::default(),
             partial_result_params: Default::default(),
         },
         json!([{
             "originSelectionRange": {
-                "end": {
-                    "character": 10,
-                    "line": 13
-                },
-                "start": {
-                    "character": 8,
-                    "line":13
-                }
+                "end": { "character": 10, "line": 18 },
+                "start": { "character": 8, "line": 18 }
             },
             "targetRange": {
-                "end": {
-                    "character": 9,
-                    "line": 7
-                },
-                "start": {
-                    "character": 0,
-                    "line":6
-                }
+                "end": { "character": 9, "line": 12 },
+                "start": { "character": 0, "line":11 }
             },
             "targetSelectionRange": {
-                "end": {
-                    "character": 8,
-                    "line": 7
-                },
-                "start": {
-                    "character": 7,
-                    "line": 7
-                }
+                "end": { "character": 8, "line": 12 },
+                "start": { "character": 7, "line": 12 }
             },
             "targetUri": "file:///[..]src/main.rs"
         }]),
@@ -679,7 +598,7 @@ fn resolve_proc_macro() {
     }
     let server = Project::with_fixture(
         r###"
-//- foo/Cargo.toml
+//- /foo/Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
@@ -687,7 +606,7 @@ edition = "2018"
 [dependencies]
 bar = {path = "../bar"}
 
-//- foo/src/main.rs
+//- /foo/src/main.rs
 use bar::Bar;
 trait Bar {
   fn bar();
@@ -698,7 +617,7 @@ fn main() {
   Foo::bar();
 }
 
-//- bar/Cargo.toml
+//- /bar/Cargo.toml
 [package]
 name = "bar"
 version = "0.0.0"
@@ -707,7 +626,7 @@ edition = "2018"
 [lib]
 proc-macro = true
 
-//- bar/src/lib.rs
+//- /bar/src/lib.rs
 extern crate proc_macro;
 use proc_macro::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
 macro_rules! t {
diff --git a/crates/rust-analyzer/tests/heavy_tests/support.rs b/crates/rust-analyzer/tests/heavy_tests/support.rs
index 66a6f4d54..e51796d36 100644
--- a/crates/rust-analyzer/tests/heavy_tests/support.rs
+++ b/crates/rust-analyzer/tests/heavy_tests/support.rs
@@ -9,20 +9,19 @@ use std::{
 use crossbeam_channel::{after, select, Receiver};
 use lsp_server::{Connection, Message, Notification, Request};
 use lsp_types::{
-    notification::{DidOpenTextDocument, Exit},
-    request::Shutdown,
-    DidOpenTextDocumentParams, TextDocumentIdentifier, TextDocumentItem, Url, WorkDoneProgress,
+    notification::Exit, request::Shutdown, TextDocumentIdentifier, Url, WorkDoneProgress,
 };
 use lsp_types::{ProgressParams, ProgressParamsValue};
-use serde::Serialize;
-use serde_json::{to_string_pretty, Value};
-use tempfile::TempDir;
-use test_utils::{find_mismatch, parse_fixture};
-
+use ra_project_model::ProjectManifest;
 use rust_analyzer::{
-    config::{ClientCapsConfig, Config},
+    config::{ClientCapsConfig, Config, FilesConfig, FilesWatcher, LinkedProject},
     main_loop,
 };
+use serde::Serialize;
+use serde_json::{to_string_pretty, Value};
+use tempfile::TempDir;
+use test_utils::{find_mismatch, Fixture};
+use vfs::AbsPathBuf;
 
 pub struct Project<'a> {
     fixture: &'a str,
@@ -42,7 +41,7 @@ impl<'a> Project<'a> {
         self
     }
 
-    pub fn root(mut self, path: &str) -> Project<'a> {
+    pub(crate) fn root(mut self, path: &str) -> Project<'a> {
         self.roots.push(path.into());
         self
     }
@@ -65,16 +64,23 @@ impl<'a> Project<'a> {
             ra_prof::init_from(crate::PROFILE);
         });
 
-        let mut paths = vec![];
-
-        for entry in parse_fixture(self.fixture) {
-            let path = tmp_dir.path().join(entry.meta.path().as_str());
+        for entry in Fixture::parse(self.fixture) {
+            let path = tmp_dir.path().join(&entry.path['/'.len_utf8()..]);
             fs::create_dir_all(path.parent().unwrap()).unwrap();
             fs::write(path.as_path(), entry.text.as_bytes()).unwrap();
-            paths.push((path, entry.text));
         }
 
-        let roots = self.roots.into_iter().map(|root| tmp_dir.path().join(root)).collect();
+        let tmp_dir_path = AbsPathBuf::assert(tmp_dir.path().to_path_buf());
+        let mut roots =
+            self.roots.into_iter().map(|root| tmp_dir_path.join(root)).collect::<Vec<_>>();
+        if roots.is_empty() {
+            roots.push(tmp_dir_path.clone());
+        }
+        let linked_projects = roots
+            .into_iter()
+            .map(|it| ProjectManifest::discover_single(&it).unwrap())
+            .map(LinkedProject::from)
+            .collect::<Vec<_>>();
 
         let mut config = Config {
             client_caps: ClientCapsConfig {
@@ -84,14 +90,15 @@ impl<'a> Project<'a> {
                 ..Default::default()
             },
             with_sysroot: self.with_sysroot,
-            ..Config::default()
+            linked_projects,
+            files: FilesConfig { watcher: FilesWatcher::Client, exclude: Vec::new() },
+            ..Config::new(tmp_dir_path)
         };
-
         if let Some(f) = &self.config {
             f(&mut config)
         }
 
-        Server::new(tmp_dir, config, roots, paths)
+        Server::new(tmp_dir, config)
     }
 }
 
@@ -109,36 +116,15 @@ pub struct Server {
 }
 
 impl Server {
-    fn new(
-        dir: TempDir,
-        config: Config,
-        roots: Vec<PathBuf>,
-        files: Vec<(PathBuf, String)>,
-    ) -> Server {
-        let path = dir.path().to_path_buf();
-
-        let roots = if roots.is_empty() { vec![path] } else { roots };
+    fn new(dir: TempDir, config: Config) -> Server {
         let (connection, client) = Connection::memory();
 
         let _thread = jod_thread::Builder::new()
             .name("test server".to_string())
-            .spawn(move || main_loop(roots, config, connection).unwrap())
+            .spawn(move || main_loop(config, connection).unwrap())
             .expect("failed to spawn a thread");
 
-        let res =
-            Server { req_id: Cell::new(1), dir, messages: Default::default(), client, _thread };
-
-        for (path, text) in files {
-            res.notification::<DidOpenTextDocument>(DidOpenTextDocumentParams {
-                text_document: TextDocumentItem {
-                    uri: Url::from_file_path(path).unwrap(),
-                    language_id: "rust".to_string(),
-                    version: 0,
-                    text,
-                },
-            })
-        }
-        res
+        Server { req_id: Cell::new(1), dir, messages: Default::default(), client, _thread }
     }
 
     pub fn doc_id(&self, rel_path: &str) -> TextDocumentIdentifier {
@@ -188,8 +174,21 @@ impl Server {
         self.client.sender.send(r.into()).unwrap();
         while let Some(msg) = self.recv() {
             match msg {
-                Message::Request(req) if req.method == "window/workDoneProgress/create" => (),
-                Message::Request(req) => panic!("unexpected request: {:?}", req),
+                Message::Request(req) => {
+                    if req.method == "window/workDoneProgress/create" {
+                        continue;
+                    }
+                    if req.method == "client/registerCapability" {
+                        let params = req.params.to_string();
+                        if ["workspace/didChangeWatchedFiles", "textDocument/didSave"]
+                            .iter()
+                            .any(|&it| params.contains(it))
+                        {
+                            continue;
+                        }
+                    }
+                    panic!("unexpected request: {:?}", req)
+                }
                 Message::Notification(_) => (),
                 Message::Response(res) => {
                     assert_eq!(res.id, id);
@@ -209,7 +208,7 @@ impl Server {
                     ProgressParams {
                         token: lsp_types::ProgressToken::String(ref token),
                         value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(_)),
-                    } if token == "rustAnalyzer/startup" => true,
+                    } if token == "rustAnalyzer/roots scanned" => true,
                     _ => false,
                 }
             }
diff --git a/crates/stdx/Cargo.toml b/crates/stdx/Cargo.toml
index f9e380c10..4c0b85861 100644
--- a/crates/stdx/Cargo.toml
+++ b/crates/stdx/Cargo.toml
@@ -3,6 +3,7 @@ name = "stdx"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
 edition = "2018"
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
diff --git a/crates/stdx/src/lib.rs b/crates/stdx/src/lib.rs
index 71a57fba2..988853ed2 100644
--- a/crates/stdx/src/lib.rs
+++ b/crates/stdx/src/lib.rs
@@ -1,31 +1,13 @@
 //! Missing batteries for standard libraries.
-
 use std::{cell::Cell, fmt, time::Instant};
 
+mod macros;
+
 #[inline(always)]
 pub fn is_ci() -> bool {
     option_env!("CI").is_some()
 }
 
-#[macro_export]
-macro_rules! eprintln {
-    ($($tt:tt)*) => {{
-        if $crate::is_ci() {
-            panic!("Forgot to remove debug-print?")
-        }
-        std::eprintln!($($tt)*)
-    }}
-}
-
-/// Appends formatted string to a `String`.
-#[macro_export]
-macro_rules! format_to {
-    ($buf:expr) => ();
-    ($buf:expr, $lit:literal $($arg:tt)*) => {
-        { use ::std::fmt::Write as _; let _ = ::std::write!($buf, $lit $($arg)*); }
-    };
-}
-
 pub trait SepBy: Sized {
     /// Returns an `impl fmt::Display`, which joins elements via a separator.
     fn sep_by<'a>(self, sep: &'a str) -> SepByBuilder<'a, Self>;
@@ -88,6 +70,8 @@ where
         Ok(())
     }
 }
+
+#[must_use]
 pub fn timeit(label: &'static str) -> impl Drop {
     struct Guard {
         label: &'static str,
@@ -124,3 +108,90 @@ pub fn replace(buf: &mut String, from: char, to: &str) {
     // FIXME: do this in place.
     *buf = buf.replace(from, to)
 }
+
+pub fn split_delim(haystack: &str, delim: char) -> Option<(&str, &str)> {
+    let idx = haystack.find(delim)?;
+    Some((&haystack[..idx], &haystack[idx + delim.len_utf8()..]))
+}
+
+pub fn trim_indent(mut text: &str) -> String {
+    if text.starts_with('\n') {
+        text = &text[1..];
+    }
+    let indent = text
+        .lines()
+        .filter(|it| !it.trim().is_empty())
+        .map(|it| it.len() - it.trim_start().len())
+        .min()
+        .unwrap_or(0);
+    lines_with_ends(text)
+        .map(
+            |line| {
+                if line.len() <= indent {
+                    line.trim_start_matches(' ')
+                } else {
+                    &line[indent..]
+                }
+            },
+        )
+        .collect()
+}
+
+pub fn lines_with_ends(text: &str) -> LinesWithEnds {
+    LinesWithEnds { text }
+}
+
+pub struct LinesWithEnds<'a> {
+    text: &'a str,
+}
+
+impl<'a> Iterator for LinesWithEnds<'a> {
+    type Item = &'a str;
+    fn next(&mut self) -> Option<&'a str> {
+        if self.text.is_empty() {
+            return None;
+        }
+        let idx = self.text.find('\n').map_or(self.text.len(), |it| it + 1);
+        let (res, next) = self.text.split_at(idx);
+        self.text = next;
+        Some(res)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_trim_indent() {
+        assert_eq!(trim_indent(""), "");
+        assert_eq!(
+            trim_indent(
+                "
+            hello
+            world
+"
+            ),
+            "hello\nworld\n"
+        );
+        assert_eq!(
+            trim_indent(
+                "
+            hello
+            world"
+            ),
+            "hello\nworld"
+        );
+        assert_eq!(trim_indent("    hello\n    world\n"), "hello\nworld\n");
+        assert_eq!(
+            trim_indent(
+                "
+            fn main() {
+                return 92;
+            }
+        "
+            ),
+            "fn main() {\n    return 92;\n}\n"
+        );
+    }
+}
diff --git a/crates/stdx/src/macros.rs b/crates/stdx/src/macros.rs
new file mode 100644
index 000000000..bf298460f
--- /dev/null
+++ b/crates/stdx/src/macros.rs
@@ -0,0 +1,40 @@
+//! Convenience macros.
+#[macro_export]
+macro_rules! eprintln {
+    ($($tt:tt)*) => {{
+        if $crate::is_ci() {
+            panic!("Forgot to remove debug-print?")
+        }
+        std::eprintln!($($tt)*)
+    }}
+}
+
+/// Appends formatted string to a `String`.
+#[macro_export]
+macro_rules! format_to {
+    ($buf:expr) => ();
+    ($buf:expr, $lit:literal $($arg:tt)*) => {
+        { use ::std::fmt::Write as _; let _ = ::std::write!($buf, $lit $($arg)*); }
+    };
+}
+
+// Generates `From` impls for `Enum E { Foo(Foo), Bar(Bar) }` enums
+#[macro_export]
+macro_rules! impl_from {
+    ($($variant:ident $(($($sub_variant:ident),*))?),* for $enum:ident) => {
+        $(
+            impl From<$variant> for $enum {
+                fn from(it: $variant) -> $enum {
+                    $enum::$variant(it)
+                }
+            }
+            $($(
+                impl From<$sub_variant> for $enum {
+                    fn from(it: $sub_variant) -> $enum {
+                        $enum::$variant($variant::$sub_variant(it))
+                    }
+                }
+            )*)?
+        )*
+    }
+}
diff --git a/crates/test_utils/Cargo.toml b/crates/test_utils/Cargo.toml
index 4d185b01c..e719f4f7c 100644
--- a/crates/test_utils/Cargo.toml
+++ b/crates/test_utils/Cargo.toml
@@ -3,15 +3,15 @@ edition = "2018"
 name = "test_utils"
 version = "0.1.0"
 authors = ["rust-analyzer developers"]
+license = "MIT OR Apache-2.0"
 
 [lib]
 doctest = false
 
 [dependencies]
+# Avoid adding deps here, this crate is widely used in tests it should compile fast!
 difference = "2.0.0"
 text-size = "1.0.0"
 serde_json = "1.0.48"
-relative-path = "1.0.0"
 rustc-hash = "1.1.0"
-
-ra_cfg = { path = "../ra_cfg" }
\ No newline at end of file
+stdx = { path = "../stdx" }
diff --git a/crates/test_utils/src/fixture.rs b/crates/test_utils/src/fixture.rs
new file mode 100644
index 000000000..ed764046b
--- /dev/null
+++ b/crates/test_utils/src/fixture.rs
@@ -0,0 +1,142 @@
+//! Defines `Fixture` -- a convenient way to describe the initial state of
+//! rust-analyzer database from a single string.
+
+use rustc_hash::FxHashMap;
+use stdx::{lines_with_ends, split_delim, trim_indent};
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Fixture {
+    pub path: String,
+    pub text: String,
+    pub krate: Option<String>,
+    pub deps: Vec<String>,
+    pub cfg_atoms: Vec<String>,
+    pub cfg_key_values: Vec<(String, String)>,
+    pub edition: Option<String>,
+    pub env: FxHashMap<String, String>,
+}
+
+impl Fixture {
+    /// Parses text which looks like this:
+    ///
+    ///  ```not_rust
+    ///  //- some meta
+    ///  line 1
+    ///  line 2
+    ///  // - other meta
+    ///  ```
+    pub fn parse(ra_fixture: &str) -> Vec<Fixture> {
+        let fixture = trim_indent(ra_fixture);
+
+        let mut res: Vec<Fixture> = Vec::new();
+
+        let default = if ra_fixture.contains("//-") { None } else { Some("//- /main.rs") };
+
+        for (ix, line) in default.into_iter().chain(lines_with_ends(&fixture)).enumerate() {
+            if line.contains("//-") {
+                assert!(
+                    line.starts_with("//-"),
+                    "Metadata line {} has invalid indentation. \
+                     All metadata lines need to have the same indentation.\n\
+                     The offending line: {:?}",
+                    ix,
+                    line
+                );
+            }
+
+            if line.starts_with("//-") {
+                let meta = Fixture::parse_meta_line(line);
+                res.push(meta)
+            } else if let Some(entry) = res.last_mut() {
+                entry.text.push_str(line);
+            }
+        }
+
+        res
+    }
+
+    //- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
+    fn parse_meta_line(meta: &str) -> Fixture {
+        assert!(meta.starts_with("//-"));
+        let meta = meta["//-".len()..].trim();
+        let components = meta.split_ascii_whitespace().collect::<Vec<_>>();
+
+        let path = components[0].to_string();
+        assert!(path.starts_with('/'));
+
+        let mut krate = None;
+        let mut deps = Vec::new();
+        let mut edition = None;
+        let mut cfg_atoms = Vec::new();
+        let mut cfg_key_values = Vec::new();
+        let mut env = FxHashMap::default();
+        for component in components[1..].iter() {
+            let (key, value) = split_delim(component, ':').unwrap();
+            match key {
+                "crate" => krate = Some(value.to_string()),
+                "deps" => deps = value.split(',').map(|it| it.to_string()).collect(),
+                "edition" => edition = Some(value.to_string()),
+                "cfg" => {
+                    for entry in value.split(',') {
+                        match split_delim(entry, '=') {
+                            Some((k, v)) => cfg_key_values.push((k.to_string(), v.to_string())),
+                            None => cfg_atoms.push(entry.to_string()),
+                        }
+                    }
+                }
+                "env" => {
+                    for key in value.split(',') {
+                        if let Some((k, v)) = split_delim(key, '=') {
+                            env.insert(k.into(), v.into());
+                        }
+                    }
+                }
+                _ => panic!("bad component: {:?}", component),
+            }
+        }
+
+        Fixture {
+            path,
+            text: String::new(),
+            krate: krate,
+            deps,
+            cfg_atoms,
+            cfg_key_values,
+            edition,
+            env,
+        }
+    }
+}
+
+#[test]
+#[should_panic]
+fn parse_fixture_checks_further_indented_metadata() {
+    Fixture::parse(
+        r"
+        //- /lib.rs
+          mod bar;
+
+          fn foo() {}
+          //- /bar.rs
+          pub fn baz() {}
+          ",
+    );
+}
+
+#[test]
+fn parse_fixture_gets_full_meta() {
+    let parsed = Fixture::parse(
+        r"
+    //- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b,atom env:OUTDIR=path/to,OTHER=foo
+    mod m;
+    ",
+    );
+    assert_eq!(1, parsed.len());
+
+    let meta = &parsed[0];
+    assert_eq!("mod m;\n", meta.text);
+
+    assert_eq!("foo", meta.krate.as_ref().unwrap());
+    assert_eq!("/lib.rs", meta.path);
+    assert_eq!(2, meta.env.len());
+}
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 1bd97215c..ad586c882 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -8,20 +8,22 @@
 
 #[macro_use]
 pub mod mark;
+mod fixture;
 
 use std::{
-    fs,
-    path::{Path, PathBuf},
+    convert::{TryFrom, TryInto},
+    env, fs,
+    path::PathBuf,
 };
 
-pub use ra_cfg::CfgOptions;
-
-pub use relative_path::{RelativePath, RelativePathBuf};
-pub use rustc_hash::FxHashMap;
 use serde_json::Value;
+use stdx::lines_with_ends;
 use text_size::{TextRange, TextSize};
 
 pub use difference::Changeset as __Changeset;
+pub use rustc_hash::FxHashMap;
+
+pub use crate::fixture::Fixture;
 
 pub const CURSOR_MARKER: &str = "<|>";
 
@@ -43,7 +45,7 @@ macro_rules! assert_eq_text {
             if left.trim() == right.trim() {
                 eprintln!("Left:\n{:?}\n\nRight:\n{:?}\n\nWhitespace difference\n", left, right);
             } else {
-                let changeset = $crate::__Changeset::new(right, left, "\n");
+                let changeset = $crate::__Changeset::new(left, right, "\n");
                 eprintln!("Left:\n{}\n\nRight:\n{}\n\nDiff:\n{}\n", left, right, changeset);
             }
             eprintln!($($tt)*);
@@ -97,7 +99,7 @@ impl From<RangeOrOffset> for TextRange {
     fn from(selection: RangeOrOffset) -> Self {
         match selection {
             RangeOrOffset::Range(it) => it,
-            RangeOrOffset::Offset(it) => TextRange::new(it, it),
+            RangeOrOffset::Offset(it) => TextRange::empty(it),
         }
     }
 }
@@ -116,8 +118,8 @@ pub fn extract_range_or_offset(text: &str) -> (RangeOrOffset, String) {
 }
 
 /// Extracts ranges, marked with `<tag> </tag>` pairs from the `text`
-pub fn extract_ranges(mut text: &str, tag: &str) -> (Vec<TextRange>, String) {
-    let open = format!("<{}>", tag);
+pub fn extract_tags(mut text: &str, tag: &str) -> (Vec<(TextRange, Option<String>)>, String) {
+    let open = format!("<{}", tag);
     let close = format!("</{}>", tag);
     let mut ranges = Vec::new();
     let mut res = String::new();
@@ -132,22 +134,35 @@ pub fn extract_ranges(mut text: &str, tag: &str) -> (Vec<TextRange>, String) {
                 res.push_str(&text[..i]);
                 text = &text[i..];
                 if text.starts_with(&open) {
-                    text = &text[open.len()..];
+                    let close_open = text.find('>').unwrap();
+                    let attr = text[open.len()..close_open].trim();
+                    let attr = if attr.is_empty() { None } else { Some(attr.to_string()) };
+                    text = &text[close_open + '>'.len_utf8()..];
                     let from = TextSize::of(&res);
-                    stack.push(from);
+                    stack.push((from, attr));
                 } else if text.starts_with(&close) {
                     text = &text[close.len()..];
-                    let from = stack.pop().unwrap_or_else(|| panic!("unmatched </{}>", tag));
+                    let (from, attr) =
+                        stack.pop().unwrap_or_else(|| panic!("unmatched </{}>", tag));
                     let to = TextSize::of(&res);
-                    ranges.push(TextRange::new(from, to));
+                    ranges.push((TextRange::new(from, to), attr));
+                } else {
+                    res.push('<');
+                    text = &text['<'.len_utf8()..];
                 }
             }
         }
     }
     assert!(stack.is_empty(), "unmatched <{}>", tag);
-    ranges.sort_by_key(|r| (r.start(), r.end()));
+    ranges.sort_by_key(|r| (r.0.start(), r.0.end()));
     (ranges, res)
 }
+#[test]
+fn test_extract_tags() {
+    let (tags, text) = extract_tags(r#"<tag fn>fn <tag>main</tag>() {}</tag>"#, "tag");
+    let actual = tags.into_iter().map(|(range, attr)| (&text[range], attr)).collect::<Vec<_>>();
+    assert_eq!(actual, vec![("fn main() {}", Some("fn".into())), ("main", None),]);
+}
 
 /// Inserts `<|>` marker into the `text` at `offset`.
 pub fn add_cursor(text: &str, offset: TextSize) -> String {
@@ -159,294 +174,108 @@ pub fn add_cursor(text: &str, offset: TextSize) -> String {
     res
 }
 
-#[derive(Debug, Eq, PartialEq)]
-pub struct FixtureEntry {
-    pub meta: FixtureMeta,
-    pub text: String,
-}
-
-#[derive(Debug, Eq, PartialEq)]
-pub enum FixtureMeta {
-    Root { path: RelativePathBuf },
-    File(FileMeta),
-}
-
-#[derive(Debug, Eq, PartialEq)]
-pub struct FileMeta {
-    pub path: RelativePathBuf,
-    pub crate_name: Option<String>,
-    pub deps: Vec<String>,
-    pub cfg: CfgOptions,
-    pub edition: Option<String>,
-    pub env: FxHashMap<String, String>,
-}
-
-impl FixtureMeta {
-    pub fn path(&self) -> &RelativePath {
-        match self {
-            FixtureMeta::Root { path } => &path,
-            FixtureMeta::File(f) => &f.path,
-        }
-    }
-
-    pub fn crate_name(&self) -> Option<&String> {
-        match self {
-            FixtureMeta::File(f) => f.crate_name.as_ref(),
-            _ => None,
-        }
-    }
-
-    pub fn cfg_options(&self) -> Option<&CfgOptions> {
-        match self {
-            FixtureMeta::File(f) => Some(&f.cfg),
-            _ => None,
-        }
-    }
-
-    pub fn edition(&self) -> Option<&String> {
-        match self {
-            FixtureMeta::File(f) => f.edition.as_ref(),
-            _ => None,
-        }
-    }
-
-    pub fn env(&self) -> impl Iterator<Item = (&String, &String)> {
-        struct EnvIter<'a> {
-            iter: Option<std::collections::hash_map::Iter<'a, String, String>>,
-        }
-
-        impl<'a> EnvIter<'a> {
-            fn new(meta: &'a FixtureMeta) -> Self {
-                Self {
-                    iter: match meta {
-                        FixtureMeta::File(f) => Some(f.env.iter()),
-                        _ => None,
-                    },
+/// Extracts `//^ some text` annotations
+pub fn extract_annotations(text: &str) -> Vec<(TextRange, String)> {
+    let mut res = Vec::new();
+    let mut prev_line_start: Option<TextSize> = None;
+    let mut line_start: TextSize = 0.into();
+    let mut prev_line_annotations: Vec<(TextSize, usize)> = Vec::new();
+    for line in lines_with_ends(text) {
+        let mut this_line_annotations = Vec::new();
+        if let Some(idx) = line.find("//") {
+            let annotation_offset = TextSize::of(&line[..idx + "//".len()]);
+            for annotation in extract_line_annotations(&line[idx + "//".len()..]) {
+                match annotation {
+                    LineAnnotation::Annotation { mut range, content } => {
+                        range += annotation_offset;
+                        this_line_annotations.push((range.end(), res.len()));
+                        res.push((range + prev_line_start.unwrap(), content))
+                    }
+                    LineAnnotation::Continuation { mut offset, content } => {
+                        offset += annotation_offset;
+                        let &(_, idx) = prev_line_annotations
+                            .iter()
+                            .find(|&&(off, _idx)| off == offset)
+                            .unwrap();
+                        res[idx].1.push('\n');
+                        res[idx].1.push_str(&content);
+                        res[idx].1.push('\n');
+                    }
                 }
             }
         }
 
-        impl<'a> Iterator for EnvIter<'a> {
-            type Item = (&'a String, &'a String);
-            fn next(&mut self) -> Option<Self::Item> {
-                self.iter.as_mut().and_then(|i| i.next())
-            }
-        }
-
-        EnvIter::new(self)
-    }
-}
+        prev_line_start = Some(line_start);
+        line_start += TextSize::of(line);
 
-/// Parses text which looks like this:
-///
-///  ```not_rust
-///  //- some meta
-///  line 1
-///  line 2
-///  // - other meta
-///  ```
-pub fn parse_fixture(ra_fixture: &str) -> Vec<FixtureEntry> {
-    let fixture = indent_first_line(ra_fixture);
-    let margin = fixture_margin(&fixture);
-
-    let mut lines = fixture
-        .split('\n') // don't use `.lines` to not drop `\r\n`
-        .enumerate()
-        .filter_map(|(ix, line)| {
-            if line.len() >= margin {
-                assert!(line[..margin].trim().is_empty());
-                let line_content = &line[margin..];
-                if !line_content.starts_with("//-") {
-                    assert!(
-                        !line_content.contains("//-"),
-                        r#"Metadata line {} has invalid indentation. All metadata lines need to have the same indentation.
-The offending line: {:?}"#,
-                        ix,
-                        line
-                    );
-                }
-                Some(line_content)
-            } else {
-                assert!(line.trim().is_empty());
-                None
-            }
-        });
-
-    let mut res: Vec<FixtureEntry> = Vec::new();
-    for line in lines.by_ref() {
-        if line.starts_with("//-") {
-            let meta = line["//-".len()..].trim().to_string();
-            let meta = parse_meta(&meta);
-            res.push(FixtureEntry { meta, text: String::new() })
-        } else if let Some(entry) = res.last_mut() {
-            entry.text.push_str(line);
-            entry.text.push('\n');
-        }
+        prev_line_annotations = this_line_annotations;
     }
     res
 }
 
-//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
-fn parse_meta(meta: &str) -> FixtureMeta {
-    let components = meta.split_ascii_whitespace().collect::<Vec<_>>();
-
-    if components[0] == "root" {
-        let path: RelativePathBuf = components[1].into();
-        assert!(path.starts_with("/") && path.ends_with("/"));
-        return FixtureMeta::Root { path };
-    }
+enum LineAnnotation {
+    Annotation { range: TextRange, content: String },
+    Continuation { offset: TextSize, content: String },
+}
 
-    let path: RelativePathBuf = components[0].into();
-    assert!(path.starts_with("/"));
-
-    let mut krate = None;
-    let mut deps = Vec::new();
-    let mut edition = None;
-    let mut cfg = CfgOptions::default();
-    let mut env = FxHashMap::default();
-    for component in components[1..].iter() {
-        let (key, value) = split1(component, ':').unwrap();
-        match key {
-            "crate" => krate = Some(value.to_string()),
-            "deps" => deps = value.split(',').map(|it| it.to_string()).collect(),
-            "edition" => edition = Some(value.to_string()),
-            "cfg" => {
-                for key in value.split(',') {
-                    match split1(key, '=') {
-                        None => cfg.insert_atom(key.into()),
-                        Some((k, v)) => cfg.insert_key_value(k.into(), v.into()),
-                    }
-                }
-            }
-            "env" => {
-                for key in value.split(',') {
-                    if let Some((k, v)) = split1(key, '=') {
-                        env.insert(k.into(), v.into());
-                    }
-                }
+fn extract_line_annotations(mut line: &str) -> Vec<LineAnnotation> {
+    let mut res = Vec::new();
+    let mut offset: TextSize = 0.into();
+    let marker: fn(char) -> bool = if line.contains('^') { |c| c == '^' } else { |c| c == '|' };
+    loop {
+        match line.find(marker) {
+            Some(idx) => {
+                offset += TextSize::try_from(idx).unwrap();
+                line = &line[idx..];
             }
-            _ => panic!("bad component: {:?}", component),
+            None => break,
+        };
+
+        let mut len = line.chars().take_while(|&it| it == '^').count();
+        let mut continuation = false;
+        if len == 0 {
+            assert!(line.starts_with('|'));
+            continuation = true;
+            len = 1;
         }
+        let range = TextRange::at(offset, len.try_into().unwrap());
+        let next = line[len..].find(marker).map_or(line.len(), |it| it + len);
+        let content = line[len..][..next - len].trim().to_string();
+
+        let annotation = if continuation {
+            LineAnnotation::Continuation { offset: range.end(), content }
+        } else {
+            LineAnnotation::Annotation { range, content }
+        };
+        res.push(annotation);
+
+        line = &line[next..];
+        offset += TextSize::try_from(next).unwrap();
     }
 
-    FixtureMeta::File(FileMeta { path, crate_name: krate, deps, edition, cfg, env })
-}
-
-fn split1(haystack: &str, delim: char) -> Option<(&str, &str)> {
-    let idx = haystack.find(delim)?;
-    Some((&haystack[..idx], &haystack[idx + delim.len_utf8()..]))
-}
-
-/// Adjusts the indentation of the first line to the minimum indentation of the rest of the lines.
-/// This allows fixtures to start off in a different indentation, e.g. to align the first line with
-/// the other lines visually:
-/// ```
-/// let fixture = "//- /lib.rs
-///                mod foo;
-///                //- /foo.rs
-///                fn bar() {}
-/// ";
-/// assert_eq!(fixture_margin(fixture),
-/// "               //- /lib.rs
-///                mod foo;
-///                //- /foo.rs
-///                fn bar() {}
-/// ")
-/// ```
-fn indent_first_line(fixture: &str) -> String {
-    if fixture.is_empty() {
-        return String::new();
-    }
-    let mut lines = fixture.lines();
-    let first_line = lines.next().unwrap();
-    if first_line.contains("//-") {
-        let rest = lines.collect::<Vec<_>>().join("\n");
-        let fixed_margin = fixture_margin(&rest);
-        let fixed_indent = fixed_margin - indent_len(first_line);
-        format!("\n{}{}\n{}", " ".repeat(fixed_indent), first_line, rest)
-    } else {
-        fixture.to_owned()
-    }
-}
-
-fn fixture_margin(fixture: &str) -> usize {
-    fixture
-        .lines()
-        .filter(|it| it.trim_start().starts_with("//-"))
-        .map(indent_len)
-        .next()
-        .expect("empty fixture")
-}
-
-fn indent_len(s: &str) -> usize {
-    s.len() - s.trim_start().len()
+    res
 }
 
 #[test]
-#[should_panic]
-fn parse_fixture_checks_further_indented_metadata() {
-    parse_fixture(
-        r"
-        //- /lib.rs
-          mod bar;
-
-          fn foo() {}
-          //- /bar.rs
-          pub fn baz() {}
-          ",
+fn test_extract_annotations() {
+    let text = stdx::trim_indent(
+        r#"
+fn main() {
+    let (x,     y) = (9, 2);
+       //^ def  ^ def
+    zoo + 1
+} //^^^ type:
+  //  | i32
+    "#,
     );
-}
-
-#[test]
-fn parse_fixture_can_handle_dedented_first_line() {
-    let fixture = "//- /lib.rs
-                   mod foo;
-                   //- /foo.rs
-                   struct Bar;
-";
+    let res = extract_annotations(&text)
+        .into_iter()
+        .map(|(range, ann)| (&text[range], ann))
+        .collect::<Vec<_>>();
     assert_eq!(
-        parse_fixture(fixture),
-        parse_fixture(
-            "//- /lib.rs
-mod foo;
-//- /foo.rs
-struct Bar;
-"
-        )
-    )
-}
-
-#[test]
-fn parse_fixture_gets_full_meta() {
-    let parsed = parse_fixture(
-        r"
-    //- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b,atom env:OUTDIR=path/to,OTHER=foo
-    mod m;
-    ",
+        res,
+        vec![("x", "def".into()), ("y", "def".into()), ("zoo", "type:\ni32\n".into()),]
     );
-    assert_eq!(1, parsed.len());
-
-    let parsed = &parsed[0];
-    assert_eq!("mod m;\n\n", parsed.text);
-
-    let meta = &parsed.meta;
-    assert_eq!("foo", meta.crate_name().unwrap());
-    assert_eq!("/lib.rs", meta.path());
-    assert!(meta.cfg_options().is_some());
-    assert_eq!(2, meta.env().count());
-}
-
-/// Same as `parse_fixture`, except it allow empty fixture
-pub fn parse_single_fixture(ra_fixture: &str) -> Option<FixtureEntry> {
-    if !ra_fixture.lines().any(|it| it.trim_start().starts_with("//-")) {
-        return None;
-    }
-
-    let fixtures = parse_fixture(ra_fixture);
-    if fixtures.len() > 1 {
-        panic!("too many fixtures");
-    }
-    fixtures.into_iter().nth(0)
 }
 
 // Comparison functionality borrowed from cargo:
@@ -536,85 +365,6 @@ pub fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a
     }
 }
 
-/// Calls callback `f` with input code and file paths for each `.rs` file in `test_data_dir`
-/// subdirectories defined by `paths`.
-///
-/// If the content of the matching output file differs from the output of `f()`
-/// the test will fail.
-///
-/// If there is no matching output file it will be created and filled with the
-/// output of `f()`, but the test will fail.
-pub fn dir_tests<F>(test_data_dir: &Path, paths: &[&str], outfile_extension: &str, f: F)
-where
-    F: Fn(&str, &Path) -> String,
-{
-    for (path, input_code) in collect_rust_files(test_data_dir, paths) {
-        let actual = f(&input_code, &path);
-        let path = path.with_extension(outfile_extension);
-        if !path.exists() {
-            println!("\nfile: {}", path.display());
-            println!("No .txt file with expected result, creating...\n");
-            println!("{}\n{}", input_code, actual);
-            fs::write(&path, &actual).unwrap();
-            panic!("No expected result");
-        }
-        let expected = read_text(&path);
-        assert_equal_text(&expected, &actual, &path);
-    }
-}
-
-/// Collects all `.rs` files from `dir` subdirectories defined by `paths`.
-pub fn collect_rust_files(root_dir: &Path, paths: &[&str]) -> Vec<(PathBuf, String)> {
-    paths
-        .iter()
-        .flat_map(|path| {
-            let path = root_dir.to_owned().join(path);
-            rust_files_in_dir(&path).into_iter()
-        })
-        .map(|path| {
-            let text = read_text(&path);
-            (path, text)
-        })
-        .collect()
-}
-
-/// Collects paths to all `.rs` files from `dir` in a sorted `Vec<PathBuf>`.
-fn rust_files_in_dir(dir: &Path) -> Vec<PathBuf> {
-    let mut acc = Vec::new();
-    for file in fs::read_dir(&dir).unwrap() {
-        let file = file.unwrap();
-        let path = file.path();
-        if path.extension().unwrap_or_default() == "rs" {
-            acc.push(path);
-        }
-    }
-    acc.sort();
-    acc
-}
-
-/// Returns the path to the root directory of `rust-analyzer` project.
-pub fn project_dir() -> PathBuf {
-    let dir = env!("CARGO_MANIFEST_DIR");
-    PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
-}
-
-/// Read file and normalize newlines.
-///
-/// `rustc` seems to always normalize `\r\n` newlines to `\n`:
-///
-/// ```
-/// let s = "
-/// ";
-/// assert_eq!(s.as_bytes(), &[10]);
-/// ```
-///
-/// so this should always be correct.
-pub fn read_text(path: &Path) -> String {
-    fs::read_to_string(path)
-        .unwrap_or_else(|_| panic!("File at {:?} should be valid", path))
-        .replace("\r\n", "\n")
-}
-
 /// Returns `false` if slow tests should not run, otherwise returns `true` and
 /// also creates a file at `./target/.slow_tests_cookie` which serves as a flag
 /// that slow tests did run.
@@ -629,27 +379,8 @@ pub fn skip_slow_tests() -> bool {
     should_skip
 }
 
-const REWRITE: bool = false;
-
-/// Asserts that `expected` and `actual` strings are equal. If they differ only
-/// in trailing or leading whitespace the test won't fail and
-/// the contents of `actual` will be written to the file located at `path`.
-fn assert_equal_text(expected: &str, actual: &str, path: &Path) {
-    if expected == actual {
-        return;
-    }
-    let dir = project_dir();
-    let pretty_path = path.strip_prefix(&dir).unwrap_or_else(|_| path);
-    if expected.trim() == actual.trim() {
-        println!("whitespace difference, rewriting");
-        println!("file: {}\n", pretty_path.display());
-        fs::write(path, actual).unwrap();
-        return;
-    }
-    if REWRITE {
-        println!("rewriting {}", pretty_path.display());
-        fs::write(path, actual).unwrap();
-        return;
-    }
-    assert_eq_text!(expected, actual, "file: {}", pretty_path.display());
+/// Returns the path to the root directory of `rust-analyzer` project.
+pub fn project_dir() -> PathBuf {
+    let dir = env!("CARGO_MANIFEST_DIR");
+    PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
 }
diff --git a/crates/test_utils/src/mark.rs b/crates/test_utils/src/mark.rs
index 7c309a894..97f5a93ad 100644
--- a/crates/test_utils/src/mark.rs
+++ b/crates/test_utils/src/mark.rs
@@ -62,7 +62,7 @@ pub struct MarkChecker {
 
 impl MarkChecker {
     pub fn new(mark: &'static AtomicUsize) -> MarkChecker {
-        let value_on_entry = mark.load(Ordering::SeqCst);
+        let value_on_entry = mark.load(Ordering::Relaxed);
         MarkChecker { mark, value_on_entry }
     }
 }
@@ -72,7 +72,7 @@ impl Drop for MarkChecker {
         if std::thread::panicking() {
             return;
         }
-        let value_on_exit = self.mark.load(Ordering::SeqCst);
+        let value_on_exit = self.mark.load(Ordering::Relaxed);
         assert!(value_on_exit > self.value_on_entry, "mark was not hit")
     }
 }
diff --git a/crates/vfs-notify/Cargo.toml b/crates/vfs-notify/Cargo.toml
new file mode 100644
index 000000000..95c56ffa6
--- /dev/null
+++ b/crates/vfs-notify/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "vfs-notify"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
+
+[dependencies]
+log = "0.4.8"
+rustc-hash = "1.0"
+jod-thread = "0.1.0"
+walkdir = "2.3.1"
+globset = "0.4.5"
+crossbeam-channel = "0.4.0"
+notify = "5.0.0-pre.3"
+
+vfs = { path = "../vfs" }
+paths = { path = "../paths" }
diff --git a/crates/vfs-notify/src/include.rs b/crates/vfs-notify/src/include.rs
new file mode 100644
index 000000000..59da3d77a
--- /dev/null
+++ b/crates/vfs-notify/src/include.rs
@@ -0,0 +1,42 @@
+//! See `Include`.
+use std::convert::TryFrom;
+
+use globset::{Glob, GlobSet, GlobSetBuilder};
+use paths::{RelPath, RelPathBuf};
+
+/// `Include` is the opposite of .gitignore.
+///
+/// It describes the set of files inside some directory.
+///
+/// The current implementation is very limited, it allows including file globs
+/// and recursively excluding directories.
+#[derive(Debug, Clone)]
+pub(crate) struct Include {
+    include_files: GlobSet,
+    exclude_dirs: Vec<RelPathBuf>,
+}
+
+impl Include {
+    pub(crate) fn new(include: Vec<String>) -> Include {
+        let mut include_files = GlobSetBuilder::new();
+        let mut exclude_dirs = Vec::new();
+
+        for glob in include {
+            if glob.starts_with("!/") {
+                if let Ok(path) = RelPathBuf::try_from(&glob["!/".len()..]) {
+                    exclude_dirs.push(path)
+                }
+            } else {
+                include_files.add(Glob::new(&glob).unwrap());
+            }
+        }
+        let include_files = include_files.build().unwrap();
+        Include { include_files, exclude_dirs }
+    }
+    pub(crate) fn include_file(&self, path: &RelPath) -> bool {
+        self.include_files.is_match(path)
+    }
+    pub(crate) fn exclude_dir(&self, path: &RelPath) -> bool {
+        self.exclude_dirs.iter().any(|excluded| path.starts_with(excluded))
+    }
+}
diff --git a/crates/vfs-notify/src/lib.rs b/crates/vfs-notify/src/lib.rs
new file mode 100644
index 000000000..6aaa53f63
--- /dev/null
+++ b/crates/vfs-notify/src/lib.rs
@@ -0,0 +1,230 @@
+//! An implementation of `loader::Handle`, based on `walkdir` and `notify`.
+//!
+//! The file watching bits here are untested and quite probably buggy. For this
+//! reason, by default we don't watch files and rely on editor's file watching
+//! capabilities.
+//!
+//! Hopefully, one day a reliable file watching/walking crate appears on
+//! crates.io, and we can reduce this to trivial glue code.
+mod include;
+
+use std::convert::{TryFrom, TryInto};
+
+use crossbeam_channel::{never, select, unbounded, Receiver, Sender};
+use notify::{RecommendedWatcher, RecursiveMode, Watcher};
+use paths::{AbsPath, AbsPathBuf};
+use vfs::loader;
+use walkdir::WalkDir;
+
+use crate::include::Include;
+
+#[derive(Debug)]
+pub struct NotifyHandle {
+    // Relative order of fields below is significant.
+    sender: Sender<Message>,
+    thread: jod_thread::JoinHandle,
+}
+
+#[derive(Debug)]
+enum Message {
+    Config(loader::Config),
+    Invalidate(AbsPathBuf),
+}
+
+impl loader::Handle for NotifyHandle {
+    fn spawn(sender: loader::Sender) -> NotifyHandle {
+        let actor = NotifyActor::new(sender);
+        let (sender, receiver) = unbounded::<Message>();
+        let thread = jod_thread::spawn(move || actor.run(receiver));
+        NotifyHandle { sender, thread }
+    }
+    fn set_config(&mut self, config: loader::Config) {
+        self.sender.send(Message::Config(config)).unwrap()
+    }
+    fn invalidate(&mut self, path: AbsPathBuf) {
+        self.sender.send(Message::Invalidate(path)).unwrap();
+    }
+    fn load_sync(&mut self, path: &AbsPath) -> Option<Vec<u8>> {
+        read(path)
+    }
+}
+
+type NotifyEvent = notify::Result<notify::Event>;
+
+struct NotifyActor {
+    sender: loader::Sender,
+    config: Vec<(AbsPathBuf, Include, bool)>,
+    // Drop order is significant.
+    watcher: Option<(RecommendedWatcher, Receiver<NotifyEvent>)>,
+}
+
+#[derive(Debug)]
+enum Event {
+    Message(Message),
+    NotifyEvent(NotifyEvent),
+}
+
+impl NotifyActor {
+    fn new(sender: loader::Sender) -> NotifyActor {
+        NotifyActor { sender, config: Vec::new(), watcher: None }
+    }
+    fn next_event(&self, receiver: &Receiver<Message>) -> Option<Event> {
+        let watcher_receiver = self.watcher.as_ref().map(|(_, receiver)| receiver);
+        select! {
+            recv(receiver) -> it => it.ok().map(Event::Message),
+            recv(watcher_receiver.unwrap_or(&never())) -> it => Some(Event::NotifyEvent(it.unwrap())),
+        }
+    }
+    fn run(mut self, inbox: Receiver<Message>) {
+        while let Some(event) = self.next_event(&inbox) {
+            log::debug!("vfs-notify event: {:?}", event);
+            match event {
+                Event::Message(msg) => match msg {
+                    Message::Config(config) => {
+                        self.watcher = None;
+                        if !config.watch.is_empty() {
+                            let (watcher_sender, watcher_receiver) = unbounded();
+                            let watcher = log_notify_error(Watcher::new_immediate(move |event| {
+                                watcher_sender.send(event).unwrap()
+                            }));
+                            self.watcher = watcher.map(|it| (it, watcher_receiver));
+                        }
+
+                        let n_total = config.load.len();
+                        self.send(loader::Message::Progress { n_total, n_done: 0 });
+
+                        self.config.clear();
+
+                        for (i, entry) in config.load.into_iter().enumerate() {
+                            let watch = config.watch.contains(&i);
+                            let files = self.load_entry(entry, watch);
+                            self.send(loader::Message::Loaded { files });
+                            self.send(loader::Message::Progress { n_total, n_done: i + 1 });
+                        }
+                        self.config.sort_by(|x, y| x.0.cmp(&y.0));
+                    }
+                    Message::Invalidate(path) => {
+                        let contents = read(path.as_path());
+                        let files = vec![(path, contents)];
+                        self.send(loader::Message::Loaded { files });
+                    }
+                },
+                Event::NotifyEvent(event) => {
+                    if let Some(event) = log_notify_error(event) {
+                        let files = event
+                            .paths
+                            .into_iter()
+                            .map(|path| AbsPathBuf::try_from(path).unwrap())
+                            .filter_map(|path| {
+                                let is_dir = path.is_dir();
+                                let is_file = path.is_file();
+
+                                let config_idx =
+                                    match self.config.binary_search_by(|it| it.0.cmp(&path)) {
+                                        Ok(it) => it,
+                                        Err(it) => it.saturating_sub(1),
+                                    };
+                                let include = self.config.get(config_idx).and_then(|it| {
+                                    let rel_path = path.strip_prefix(&it.0)?;
+                                    Some((rel_path, &it.1))
+                                });
+
+                                if let Some((rel_path, include)) = include {
+                                    if is_dir && include.exclude_dir(&rel_path)
+                                        || is_file && !include.include_file(&rel_path)
+                                    {
+                                        return None;
+                                    }
+                                }
+
+                                if is_dir {
+                                    self.watch(path);
+                                    return None;
+                                }
+                                if !is_file {
+                                    return None;
+                                }
+                                let contents = read(&path);
+                                Some((path, contents))
+                            })
+                            .collect();
+                        self.send(loader::Message::Loaded { files })
+                    }
+                }
+            }
+        }
+    }
+    fn load_entry(
+        &mut self,
+        entry: loader::Entry,
+        watch: bool,
+    ) -> Vec<(AbsPathBuf, Option<Vec<u8>>)> {
+        match entry {
+            loader::Entry::Files(files) => files
+                .into_iter()
+                .map(|file| {
+                    if watch {
+                        self.watch(file.clone())
+                    }
+                    let contents = read(file.as_path());
+                    (file, contents)
+                })
+                .collect::<Vec<_>>(),
+            loader::Entry::Directory { path, include } => {
+                let include = Include::new(include);
+                self.config.push((path.clone(), include.clone(), watch));
+
+                let files = WalkDir::new(&path)
+                    .into_iter()
+                    .filter_entry(|entry| {
+                        let abs_path: &AbsPath = entry.path().try_into().unwrap();
+                        match abs_path.strip_prefix(&path) {
+                            Some(rel_path) => {
+                                !(entry.file_type().is_dir() && include.exclude_dir(rel_path))
+                            }
+                            None => false,
+                        }
+                    })
+                    .filter_map(|entry| entry.ok())
+                    .filter_map(|entry| {
+                        let is_dir = entry.file_type().is_dir();
+                        let is_file = entry.file_type().is_file();
+                        let abs_path = AbsPathBuf::try_from(entry.into_path()).unwrap();
+                        if is_dir && watch {
+                            self.watch(abs_path.clone());
+                        }
+                        let rel_path = abs_path.strip_prefix(&path)?;
+                        if is_file && include.include_file(&rel_path) {
+                            Some(abs_path)
+                        } else {
+                            None
+                        }
+                    });
+
+                files
+                    .map(|file| {
+                        let contents = read(file.as_path());
+                        (file, contents)
+                    })
+                    .collect()
+            }
+        }
+    }
+
+    fn watch(&mut self, path: AbsPathBuf) {
+        if let Some((watcher, _)) = &mut self.watcher {
+            log_notify_error(watcher.watch(&path, RecursiveMode::NonRecursive));
+        }
+    }
+    fn send(&mut self, msg: loader::Message) {
+        (self.sender)(msg)
+    }
+}
+
+fn read(path: &AbsPath) -> Option<Vec<u8>> {
+    std::fs::read(path).ok()
+}
+
+fn log_notify_error<T>(res: notify::Result<T>) -> Option<T> {
+    res.map_err(|err| log::warn!("notify error: {}", err)).ok()
+}
diff --git a/crates/vfs/Cargo.toml b/crates/vfs/Cargo.toml
new file mode 100644
index 000000000..b74cdb7ff
--- /dev/null
+++ b/crates/vfs/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "vfs"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+edition = "2018"
+license = "MIT OR Apache-2.0"
+
+[lib]
+doctest = false
+
+[dependencies]
+rustc-hash = "1.0"
+fst = "0.4"
+
+paths = { path = "../paths" }
diff --git a/crates/vfs/src/file_set.rs b/crates/vfs/src/file_set.rs
new file mode 100644
index 000000000..e5e2ef530
--- /dev/null
+++ b/crates/vfs/src/file_set.rs
@@ -0,0 +1,172 @@
+//! Partitions a list of files into disjoint subsets.
+//!
+//! Files which do not belong to any explicitly configured `FileSet` belong to
+//! the default `FileSet`.
+use std::fmt;
+
+use fst::{IntoStreamer, Streamer};
+use rustc_hash::FxHashMap;
+
+use crate::{FileId, Vfs, VfsPath};
+
+#[derive(Default, Clone, Eq, PartialEq)]
+pub struct FileSet {
+    files: FxHashMap<VfsPath, FileId>,
+    paths: FxHashMap<FileId, VfsPath>,
+}
+
+impl FileSet {
+    pub fn len(&self) -> usize {
+        self.files.len()
+    }
+    pub fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        let mut base = self.paths[&anchor].clone();
+        base.pop();
+        let path = base.join(path)?;
+        let res = self.files.get(&path).copied();
+        res
+    }
+    pub fn insert(&mut self, file_id: FileId, path: VfsPath) {
+        self.files.insert(path.clone(), file_id);
+        self.paths.insert(file_id, path);
+    }
+    pub fn iter(&self) -> impl Iterator<Item = FileId> + '_ {
+        self.paths.keys().copied()
+    }
+}
+
+impl fmt::Debug for FileSet {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("FileSet").field("n_files", &self.files.len()).finish()
+    }
+}
+
+#[derive(Debug)]
+pub struct FileSetConfig {
+    n_file_sets: usize,
+    map: fst::Map<Vec<u8>>,
+}
+
+impl Default for FileSetConfig {
+    fn default() -> Self {
+        FileSetConfig::builder().build()
+    }
+}
+
+impl FileSetConfig {
+    pub fn builder() -> FileSetConfigBuilder {
+        FileSetConfigBuilder::default()
+    }
+    pub fn partition(&self, vfs: &Vfs) -> Vec<FileSet> {
+        let mut scratch_space = Vec::new();
+        let mut res = vec![FileSet::default(); self.len()];
+        for (file_id, path) in vfs.iter() {
+            let root = self.classify(&path, &mut scratch_space);
+            res[root].insert(file_id, path.clone())
+        }
+        res
+    }
+    fn len(&self) -> usize {
+        self.n_file_sets
+    }
+    fn classify(&self, path: &VfsPath, scratch_space: &mut Vec<u8>) -> usize {
+        scratch_space.clear();
+        path.encode(scratch_space);
+        let automaton = PrefixOf::new(scratch_space.as_slice());
+        let mut longest_prefix = self.len() - 1;
+        let mut stream = self.map.search(automaton).into_stream();
+        while let Some((_, v)) = stream.next() {
+            longest_prefix = v as usize;
+        }
+        longest_prefix
+    }
+}
+
+pub struct FileSetConfigBuilder {
+    roots: Vec<Vec<VfsPath>>,
+}
+
+impl Default for FileSetConfigBuilder {
+    fn default() -> Self {
+        FileSetConfigBuilder { roots: Vec::new() }
+    }
+}
+
+impl FileSetConfigBuilder {
+    pub fn len(&self) -> usize {
+        self.roots.len()
+    }
+    pub fn add_file_set(&mut self, roots: Vec<VfsPath>) {
+        self.roots.push(roots)
+    }
+    pub fn build(self) -> FileSetConfig {
+        let n_file_sets = self.roots.len() + 1;
+        let map = {
+            let mut entries = Vec::new();
+            for (i, paths) in self.roots.into_iter().enumerate() {
+                for p in paths {
+                    let mut buf = Vec::new();
+                    p.encode(&mut buf);
+                    entries.push((buf, i as u64));
+                }
+            }
+            entries.sort();
+            entries.dedup_by(|(a, _), (b, _)| a == b);
+            fst::Map::from_iter(entries).unwrap()
+        };
+        FileSetConfig { n_file_sets, map }
+    }
+}
+
+struct PrefixOf<'a> {
+    prefix_of: &'a [u8],
+}
+
+impl<'a> PrefixOf<'a> {
+    fn new(prefix_of: &'a [u8]) -> Self {
+        Self { prefix_of }
+    }
+}
+
+impl fst::Automaton for PrefixOf<'_> {
+    type State = usize;
+    fn start(&self) -> usize {
+        0
+    }
+    fn is_match(&self, &state: &usize) -> bool {
+        state != !0
+    }
+    fn can_match(&self, &state: &usize) -> bool {
+        state != !0
+    }
+    fn accept(&self, &state: &usize, byte: u8) -> usize {
+        if self.prefix_of.get(state) == Some(&byte) {
+            state + 1
+        } else {
+            !0
+        }
+    }
+}
+
+#[test]
+fn test_partitioning() {
+    let mut file_set = FileSetConfig::builder();
+    file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo".into())]);
+    file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo/bar/baz".into())]);
+    let file_set = file_set.build();
+
+    let mut vfs = Vfs::default();
+    vfs.set_file_contents(VfsPath::new_virtual_path("/foo/src/lib.rs".into()), Some(Vec::new()));
+    vfs.set_file_contents(
+        VfsPath::new_virtual_path("/foo/src/bar/baz/lib.rs".into()),
+        Some(Vec::new()),
+    );
+    vfs.set_file_contents(
+        VfsPath::new_virtual_path("/foo/bar/baz/lib.rs".into()),
+        Some(Vec::new()),
+    );
+    vfs.set_file_contents(VfsPath::new_virtual_path("/quux/lib.rs".into()), Some(Vec::new()));
+
+    let partition = file_set.partition(&vfs).into_iter().map(|it| it.len()).collect::<Vec<_>>();
+    assert_eq!(partition, vec![2, 1, 1]);
+}
diff --git a/crates/vfs/src/lib.rs b/crates/vfs/src/lib.rs
new file mode 100644
index 000000000..cdf6f1fd0
--- /dev/null
+++ b/crates/vfs/src/lib.rs
@@ -0,0 +1,140 @@
+//! # Virtual File System
+//!
+//! VFS stores all files read by rust-analyzer. Reading file contents from VFS
+//! always returns the same contents, unless VFS was explicitly modified with
+//! `set_file_contents`. All changes to VFS are logged, and can be retrieved via
+//! `take_changes` method. The pack of changes is then pushed to `salsa` and
+//! triggers incremental recomputation.
+//!
+//! Files in VFS are identified with `FileId`s -- interned paths. The notion of
+//! the path, `VfsPath` is somewhat abstract: at the moment, it is represented
+//! as an `std::path::PathBuf` internally, but this is an implementation detail.
+//!
+//! VFS doesn't do IO or file watching itself. For that, see the `loader`
+//! module. `loader::Handle` is an object-safe trait which abstracts both file
+//! loading and file watching. `Handle` is dynamically configured with a set of
+//! directory entries which should be scanned and watched. `Handle` then
+//! asynchronously pushes file changes. Directory entries are configured in
+//! free-form via list of globs, it's up to the `Handle` to interpret the globs
+//! in any specific way.
+//!
+//! A simple `WalkdirLoaderHandle` is provided, which doesn't implement watching
+//! and just scans the directory using walkdir.
+//!
+//! VFS stores a flat list of files. `FileSet` can partition this list of files
+//! into disjoint sets of files. Traversal-like operations (including getting
+//! the neighbor file by the relative path) are handled by the `FileSet`.
+//! `FileSet`s are also pushed to salsa and cause it to re-check `mod foo;`
+//! declarations when files are created or deleted.
+//!
+//! `file_set::FileSet` and `loader::Entry` play similar, but different roles.
+//! Both specify the "set of paths/files", one is geared towards file watching,
+//! the other towards salsa changes. In particular, single `file_set::FileSet`
+//! may correspond to several `loader::Entry`. For example, a crate from
+//! crates.io which uses code generation would have two `Entries` -- for sources
+//! in `~/.cargo`, and for generated code in `./target/debug/build`. It will
+//! have a single `FileSet` which unions the two sources.
+mod vfs_path;
+mod path_interner;
+pub mod file_set;
+pub mod loader;
+
+use std::{fmt, mem};
+
+use crate::path_interner::PathInterner;
+
+pub use crate::vfs_path::VfsPath;
+pub use paths::{AbsPath, AbsPathBuf};
+
+#[derive(Copy, Clone, Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct FileId(pub u32);
+
+#[derive(Default)]
+pub struct Vfs {
+    interner: PathInterner,
+    data: Vec<Option<Vec<u8>>>,
+    changes: Vec<ChangedFile>,
+}
+
+pub struct ChangedFile {
+    pub file_id: FileId,
+    pub change_kind: ChangeKind,
+}
+
+impl ChangedFile {
+    pub fn exists(&self) -> bool {
+        self.change_kind != ChangeKind::Delete
+    }
+    pub fn is_created_or_deleted(&self) -> bool {
+        matches!(self.change_kind, ChangeKind::Create | ChangeKind::Delete)
+    }
+}
+
+#[derive(Eq, PartialEq, Copy, Clone, Debug)]
+pub enum ChangeKind {
+    Create,
+    Modify,
+    Delete,
+}
+
+impl Vfs {
+    pub fn len(&self) -> usize {
+        self.data.len()
+    }
+    pub fn file_id(&self, path: &VfsPath) -> Option<FileId> {
+        self.interner.get(path).filter(|&it| self.get(it).is_some())
+    }
+    pub fn file_path(&self, file_id: FileId) -> VfsPath {
+        self.interner.lookup(file_id).clone()
+    }
+    pub fn file_contents(&self, file_id: FileId) -> &[u8] {
+        self.get(file_id).as_deref().unwrap()
+    }
+    pub fn iter(&self) -> impl Iterator<Item = (FileId, &VfsPath)> + '_ {
+        (0..self.data.len())
+            .map(|it| FileId(it as u32))
+            .filter(move |&file_id| self.get(file_id).is_some())
+            .map(move |file_id| {
+                let path = self.interner.lookup(file_id);
+                (file_id, path)
+            })
+    }
+    pub fn set_file_contents(&mut self, path: VfsPath, contents: Option<Vec<u8>>) {
+        let file_id = self.alloc_file_id(path);
+        let change_kind = match (&self.get(file_id), &contents) {
+            (None, None) => return,
+            (None, Some(_)) => ChangeKind::Create,
+            (Some(_), None) => ChangeKind::Delete,
+            (Some(old), Some(new)) if old == new => return,
+            (Some(_), Some(_)) => ChangeKind::Modify,
+        };
+
+        *self.get_mut(file_id) = contents;
+        self.changes.push(ChangedFile { file_id, change_kind })
+    }
+    pub fn has_changes(&self) -> bool {
+        !self.changes.is_empty()
+    }
+    pub fn take_changes(&mut self) -> Vec<ChangedFile> {
+        mem::take(&mut self.changes)
+    }
+    fn alloc_file_id(&mut self, path: VfsPath) -> FileId {
+        let file_id = self.interner.intern(path);
+        let idx = file_id.0 as usize;
+        let len = self.data.len().max(idx + 1);
+        self.data.resize_with(len, || None);
+        file_id
+    }
+    fn get(&self, file_id: FileId) -> &Option<Vec<u8>> {
+        &self.data[file_id.0 as usize]
+    }
+    fn get_mut(&mut self, file_id: FileId) -> &mut Option<Vec<u8>> {
+        &mut self.data[file_id.0 as usize]
+    }
+}
+
+impl fmt::Debug for Vfs {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Vfs").field("n_files", &self.data.len()).finish()
+    }
+}
diff --git a/crates/vfs/src/loader.rs b/crates/vfs/src/loader.rs
new file mode 100644
index 000000000..6de2e5b3f
--- /dev/null
+++ b/crates/vfs/src/loader.rs
@@ -0,0 +1,71 @@
+//! Object safe interface for file watching and reading.
+use std::fmt;
+
+use paths::{AbsPath, AbsPathBuf};
+
+#[derive(Debug)]
+pub enum Entry {
+    Files(Vec<AbsPathBuf>),
+    Directory { path: AbsPathBuf, include: Vec<String> },
+}
+
+#[derive(Debug)]
+pub struct Config {
+    pub load: Vec<Entry>,
+    pub watch: Vec<usize>,
+}
+
+pub enum Message {
+    Progress { n_total: usize, n_done: usize },
+    Loaded { files: Vec<(AbsPathBuf, Option<Vec<u8>>)> },
+}
+
+pub type Sender = Box<dyn Fn(Message) + Send>;
+
+pub trait Handle: fmt::Debug {
+    fn spawn(sender: Sender) -> Self
+    where
+        Self: Sized;
+    fn set_config(&mut self, config: Config);
+    fn invalidate(&mut self, path: AbsPathBuf);
+    fn load_sync(&mut self, path: &AbsPath) -> Option<Vec<u8>>;
+}
+
+impl Entry {
+    pub fn rs_files_recursively(base: AbsPathBuf) -> Entry {
+        Entry::Directory { path: base, include: globs(&["*.rs", "!/.git/"]) }
+    }
+    pub fn local_cargo_package(base: AbsPathBuf) -> Entry {
+        Entry::Directory { path: base, include: globs(&["*.rs", "!/target/", "!/.git/"]) }
+    }
+    pub fn cargo_package_dependency(base: AbsPathBuf) -> Entry {
+        Entry::Directory {
+            path: base,
+            include: globs(&["*.rs", "!/tests/", "!/examples/", "!/benches/", "!/.git/"]),
+        }
+    }
+}
+
+fn globs(globs: &[&str]) -> Vec<String> {
+    globs.iter().map(|it| it.to_string()).collect()
+}
+
+impl fmt::Debug for Message {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Message::Loaded { files } => {
+                f.debug_struct("Loaded").field("n_files", &files.len()).finish()
+            }
+            Message::Progress { n_total, n_done } => f
+                .debug_struct("Progress")
+                .field("n_total", n_total)
+                .field("n_done", n_done)
+                .finish(),
+        }
+    }
+}
+
+#[test]
+fn handle_is_object_safe() {
+    fn _assert(_: &dyn Handle) {}
+}
diff --git a/crates/vfs/src/path_interner.rs b/crates/vfs/src/path_interner.rs
new file mode 100644
index 000000000..4f70d61e8
--- /dev/null
+++ b/crates/vfs/src/path_interner.rs
@@ -0,0 +1,31 @@
+//! Maps paths to compact integer ids. We don't care about clearings paths which
+//! no longer exist -- the assumption is total size of paths we ever look at is
+//! not too big.
+use rustc_hash::FxHashMap;
+
+use crate::{FileId, VfsPath};
+
+#[derive(Default)]
+pub(crate) struct PathInterner {
+    map: FxHashMap<VfsPath, FileId>,
+    vec: Vec<VfsPath>,
+}
+
+impl PathInterner {
+    pub(crate) fn get(&self, path: &VfsPath) -> Option<FileId> {
+        self.map.get(path).copied()
+    }
+    pub(crate) fn intern(&mut self, path: VfsPath) -> FileId {
+        if let Some(id) = self.get(&path) {
+            return id;
+        }
+        let id = FileId(self.vec.len() as u32);
+        self.map.insert(path.clone(), id);
+        self.vec.push(path);
+        id
+    }
+
+    pub(crate) fn lookup(&self, id: FileId) -> &VfsPath {
+        &self.vec[id.0 as usize]
+    }
+}
diff --git a/crates/vfs/src/vfs_path.rs b/crates/vfs/src/vfs_path.rs
new file mode 100644
index 000000000..04a42264e
--- /dev/null
+++ b/crates/vfs/src/vfs_path.rs
@@ -0,0 +1,146 @@
+//! Abstract-ish representation of paths for VFS.
+use std::fmt;
+
+use paths::{AbsPath, AbsPathBuf};
+
+/// Long-term, we want to support files which do not reside in the file-system,
+/// so we treat VfsPaths as opaque identifiers.
+#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+pub struct VfsPath(VfsPathRepr);
+
+impl VfsPath {
+    /// Creates an "in-memory" path from `/`-separates string.
+    /// This is most useful for testing, to avoid windows/linux differences
+    pub fn new_virtual_path(path: String) -> VfsPath {
+        assert!(path.starts_with('/'));
+        VfsPath(VfsPathRepr::VirtualPath(VirtualPath(path)))
+    }
+
+    pub fn as_path(&self) -> Option<&AbsPath> {
+        match &self.0 {
+            VfsPathRepr::PathBuf(it) => Some(it.as_path()),
+            VfsPathRepr::VirtualPath(_) => None,
+        }
+    }
+    pub fn join(&self, path: &str) -> Option<VfsPath> {
+        match &self.0 {
+            VfsPathRepr::PathBuf(it) => {
+                let res = it.join(path).normalize();
+                Some(VfsPath(VfsPathRepr::PathBuf(res)))
+            }
+            VfsPathRepr::VirtualPath(it) => {
+                let res = it.join(path)?;
+                Some(VfsPath(VfsPathRepr::VirtualPath(res)))
+            }
+        }
+    }
+    pub fn pop(&mut self) -> bool {
+        match &mut self.0 {
+            VfsPathRepr::PathBuf(it) => it.pop(),
+            VfsPathRepr::VirtualPath(it) => it.pop(),
+        }
+    }
+    pub fn starts_with(&self, other: &VfsPath) -> bool {
+        match (&self.0, &other.0) {
+            (VfsPathRepr::PathBuf(lhs), VfsPathRepr::PathBuf(rhs)) => lhs.starts_with(rhs),
+            (VfsPathRepr::PathBuf(_), _) => false,
+            (VfsPathRepr::VirtualPath(lhs), VfsPathRepr::VirtualPath(rhs)) => lhs.starts_with(rhs),
+            (VfsPathRepr::VirtualPath(_), _) => false,
+        }
+    }
+
+    // Don't make this `pub`
+    pub(crate) fn encode(&self, buf: &mut Vec<u8>) {
+        let tag = match &self.0 {
+            VfsPathRepr::PathBuf(_) => 0,
+            VfsPathRepr::VirtualPath(_) => 1,
+        };
+        buf.push(tag);
+        match &self.0 {
+            VfsPathRepr::PathBuf(it) => {
+                let path: &std::ffi::OsStr = it.as_os_str();
+                #[cfg(windows)]
+                {
+                    use std::os::windows::ffi::OsStrExt;
+                    for wchar in path.encode_wide() {
+                        buf.extend(wchar.to_le_bytes().iter().copied());
+                    }
+                }
+                #[cfg(unix)]
+                {
+                    use std::os::unix::ffi::OsStrExt;
+                    buf.extend(path.as_bytes());
+                }
+                #[cfg(not(any(windows, unix)))]
+                {
+                    buf.extend(path.to_string_lossy().as_bytes());
+                }
+            }
+            VfsPathRepr::VirtualPath(VirtualPath(s)) => buf.extend(s.as_bytes()),
+        }
+    }
+}
+
+#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+enum VfsPathRepr {
+    PathBuf(AbsPathBuf),
+    VirtualPath(VirtualPath),
+}
+
+impl From<AbsPathBuf> for VfsPath {
+    fn from(v: AbsPathBuf) -> Self {
+        VfsPath(VfsPathRepr::PathBuf(v.normalize()))
+    }
+}
+
+impl fmt::Display for VfsPath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match &self.0 {
+            VfsPathRepr::PathBuf(it) => fmt::Display::fmt(&it.display(), f),
+            VfsPathRepr::VirtualPath(VirtualPath(it)) => fmt::Display::fmt(it, f),
+        }
+    }
+}
+
+impl fmt::Debug for VfsPath {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, f)
+    }
+}
+
+impl fmt::Debug for VfsPathRepr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match &self {
+            VfsPathRepr::PathBuf(it) => fmt::Debug::fmt(&it.display(), f),
+            VfsPathRepr::VirtualPath(VirtualPath(it)) => fmt::Debug::fmt(&it, f),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
+struct VirtualPath(String);
+
+impl VirtualPath {
+    fn starts_with(&self, other: &VirtualPath) -> bool {
+        self.0.starts_with(&other.0)
+    }
+    fn pop(&mut self) -> bool {
+        let pos = match self.0.rfind('/') {
+            Some(pos) => pos,
+            None => return false,
+        };
+        self.0 = self.0[..pos].to_string();
+        true
+    }
+    fn join(&self, mut path: &str) -> Option<VirtualPath> {
+        let mut res = self.clone();
+        while path.starts_with("../") {
+            if !res.pop() {
+                return None;
+            }
+            path = &path["../".len()..]
+        }
+        res.0 = format!("{}/{}", res.0, path);
+        Some(res)
+    }
+}