105 files changed, 4847 insertions, 3976 deletions

diff --git a/crates/ra_assists/Cargo.toml b/crates/ra_assists/Cargo.toml
index 02966bbda..beebccbd9 100644
--- a/crates/ra_assists/Cargo.toml
+++ b/crates/ra_assists/Cargo.toml
@@ -6,11 +6,9 @@ authors = ["rust-analyzer developers"]
 
 [dependencies]
 format-buf = "1.0.0"
-once_cell = "1.0.1"
 join_to_string = "0.1.3"
 itertools = "0.8.0"
-arrayvec = "0.4.10"
-rustc-hash = "1.0.1"
+rustc_lexer = "0.1.0"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_text_edit = { path = "../ra_text_edit" }
diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index 189cad7d0..e270c5d60 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -138,6 +138,7 @@ impl AssistBuilder {
 
     /// Replaces specified `node` of text with a given string, reindenting the
     /// string to maintain `node`'s existing indent.
+    // FIXME: remove in favor of ra_syntax::edit::IndentLevel::increase_indent
     pub(crate) fn replace_node_and_indent(
         &mut self,
         node: &SyntaxNode,
diff --git a/crates/ra_assists/src/assists/early_return.rs b/crates/ra_assists/src/assists/early_return.rs
new file mode 100644
index 000000000..8c975714c
--- /dev/null
+++ b/crates/ra_assists/src/assists/early_return.rs
@@ -0,0 +1,276 @@
+//! FIXME: write short doc here
+
+use crate::{
+    assist_ctx::{Assist, AssistCtx},
+    AssistId,
+};
+use hir::db::HirDatabase;
+use ra_syntax::{
+    algo::replace_children,
+    ast::edit::IndentLevel,
+    ast::make,
+    ast::Block,
+    ast::ContinueExpr,
+    ast::IfExpr,
+    ast::ReturnExpr,
+    AstNode,
+    SyntaxKind::{FN_DEF, LOOP_EXPR, L_CURLY, R_CURLY, WHILE_EXPR, WHITESPACE},
+};
+use std::ops::RangeInclusive;
+
+pub(crate) fn convert_to_guarded_return(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let if_expr: IfExpr = ctx.node_at_offset()?;
+    let expr = if_expr.condition()?.expr()?;
+    let then_block = if_expr.then_branch()?.block()?;
+    if if_expr.else_branch().is_some() {
+        return None;
+    }
+
+    let parent_block = if_expr.syntax().parent()?.ancestors().find_map(Block::cast)?;
+
+    if parent_block.expr()? != if_expr.clone().into() {
+        return None;
+    }
+
+    // check for early return and continue
+    let first_in_then_block = then_block.syntax().first_child()?.clone();
+    if ReturnExpr::can_cast(first_in_then_block.kind())
+        || ContinueExpr::can_cast(first_in_then_block.kind())
+        || first_in_then_block
+            .children()
+            .any(|x| ReturnExpr::can_cast(x.kind()) || ContinueExpr::can_cast(x.kind()))
+    {
+        return None;
+    }
+
+    let parent_container = parent_block.syntax().parent()?.parent()?;
+
+    let early_expression = match parent_container.kind() {
+        WHILE_EXPR | LOOP_EXPR => Some("continue;"),
+        FN_DEF => Some("return;"),
+        _ => None,
+    }?;
+
+    if then_block.syntax().first_child_or_token().map(|t| t.kind() == L_CURLY).is_none() {
+        return None;
+    }
+
+    then_block.syntax().last_child_or_token().filter(|t| t.kind() == R_CURLY)?;
+    let cursor_position = ctx.frange.range.start();
+
+    ctx.add_action(AssistId("convert_to_guarded_return"), "convert to guarded return", |edit| {
+        let if_indent_level = IndentLevel::from_node(&if_expr.syntax());
+        let new_if_expr =
+            if_indent_level.increase_indent(make::if_expression(&expr, early_expression));
+        let then_block_items = IndentLevel::from(1).decrease_indent(then_block.clone());
+        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 new_if_and_then_statements = new_if_expr.syntax().children_with_tokens().chain(
+            then_block_items
+                .syntax()
+                .children_with_tokens()
+                .skip(1)
+                .take_while(|i| *i != end_of_then),
+        );
+        let new_block = replace_children(
+            &parent_block.syntax(),
+            RangeInclusive::new(
+                if_expr.clone().syntax().clone().into(),
+                if_expr.syntax().clone().into(),
+            ),
+            &mut new_if_and_then_statements,
+        );
+        edit.target(if_expr.syntax().text_range());
+        edit.replace_ast(parent_block, Block::cast(new_block).unwrap());
+        edit.set_cursor(cursor_position);
+    });
+    ctx.build()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+
+    #[test]
+    fn convert_inside_fn() {
+        check_assist(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                bar();
+                if<|> true {
+                    foo();
+
+                    //comment
+                    bar();
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                bar();
+                if<|> !true {
+                    return;
+                }
+                foo();
+
+                //comment
+                bar();
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn convert_inside_while() {
+        check_assist(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                while true {
+                    if<|> true {
+                        foo();
+                        bar();
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                while true {
+                    if<|> !true {
+                        continue;
+                    }
+                    foo();
+                    bar();
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn convert_inside_loop() {
+        check_assist(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                loop {
+                    if<|> true {
+                        foo();
+                        bar();
+                    }
+                }
+            }
+            "#,
+            r#"
+            fn main() {
+                loop {
+                    if<|> !true {
+                        continue;
+                    }
+                    foo();
+                    bar();
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_already_converted_if() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                if<|> true {
+                    return;
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_already_converted_loop() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                loop {
+                    if<|> true {
+                        continue;
+                    }
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_return() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                if<|> true {
+                    return
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_else_branch() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                if<|> true {
+                    foo();
+                } else {
+                    bar()
+                }
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_statements_aftert_if() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                if<|> true {
+                    foo();
+                }
+                bar();
+            }
+            "#,
+        );
+    }
+
+    #[test]
+    fn ignore_statements_inside_if() {
+        check_assist_not_applicable(
+            convert_to_guarded_return,
+            r#"
+            fn main() {
+                if false {
+                    if<|> true {
+                        foo();
+                    }
+                }
+            }
+            "#,
+        );
+    }
+}
diff --git a/crates/ra_assists/src/assists/fill_match_arms.rs b/crates/ra_assists/src/assists/fill_match_arms.rs
index 7335cce09..e3f30b5de 100644
--- a/crates/ra_assists/src/assists/fill_match_arms.rs
+++ b/crates/ra_assists/src/assists/fill_match_arms.rs
@@ -3,7 +3,7 @@
 use std::iter;
 
 use hir::{db::HirDatabase, Adt, HasSource};
-use ra_syntax::ast::{self, make, AstNode, NameOwner};
+use ra_syntax::ast::{self, edit::IndentLevel, make, AstNode, NameOwner};
 
 use crate::{Assist, AssistCtx, AssistId};
 
@@ -30,15 +30,19 @@ pub(crate) fn fill_match_arms(mut ctx: AssistCtx<impl HirDatabase>) -> Option<As
     let variant_list = enum_def.variant_list()?;
 
     ctx.add_action(AssistId("fill_match_arms"), "fill match arms", |edit| {
-        let variants = variant_list.variants();
-        let arms = variants
-            .filter_map(build_pat)
-            .map(|pat| make::match_arm(iter::once(pat), make::expr_unit()));
-        let new_arm_list = make::match_arm_list(arms);
+        let indent_level = IndentLevel::from_node(match_arm_list.syntax());
+
+        let new_arm_list = {
+            let variants = variant_list.variants();
+            let arms = variants
+                .filter_map(build_pat)
+                .map(|pat| make::match_arm(iter::once(pat), make::expr_unit()));
+            indent_level.increase_indent(make::match_arm_list(arms))
+        };
 
         edit.target(match_expr.syntax().text_range());
         edit.set_cursor(expr.syntax().text_range().start());
-        edit.replace_node_and_indent(match_arm_list.syntax(), new_arm_list.syntax().text());
+        edit.replace_ast(match_arm_list, new_arm_list);
     });
 
     ctx.build()
diff --git a/crates/ra_assists/src/assists/move_bounds.rs b/crates/ra_assists/src/assists/move_bounds.rs
index f791d22b0..d2444b6b9 100644
--- a/crates/ra_assists/src/assists/move_bounds.rs
+++ b/crates/ra_assists/src/assists/move_bounds.rs
@@ -18,7 +18,7 @@ pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>)
     }
 
     let parent = type_param_list.syntax().parent()?;
-    if parent.children_with_tokens().find(|it| it.kind() == WHERE_CLAUSE).is_some() {
+    if parent.children_with_tokens().any(|it| it.kind() == WHERE_CLAUSE) {
         return None;
     }
 
diff --git a/crates/ra_assists/src/assists/raw_string.rs b/crates/ra_assists/src/assists/raw_string.rs
index 388ee7e97..2d2e31e51 100644
--- a/crates/ra_assists/src/assists/raw_string.rs
+++ b/crates/ra_assists/src/assists/raw_string.rs
@@ -2,6 +2,7 @@
 
 use hir::db::HirDatabase;
 use ra_syntax::{ast::AstNode, ast::Literal, TextRange, TextUnit};
+use rustc_lexer;
 
 use crate::{Assist, AssistCtx, AssistId};
 
@@ -10,13 +11,51 @@ pub(crate) fn make_raw_string(mut ctx: AssistCtx<impl HirDatabase>) -> Option<As
     if literal.token().kind() != ra_syntax::SyntaxKind::STRING {
         return None;
     }
+    let token = literal.token();
+    let text = token.text().as_str();
+    let usual_string_range = find_usual_string_range(text)?;
+    let start_of_inside = usual_string_range.start().to_usize() + 1;
+    let end_of_inside = usual_string_range.end().to_usize();
+    let inside_str = &text[start_of_inside..end_of_inside];
+    let mut unescaped = String::with_capacity(inside_str.len());
+    let mut error = Ok(());
+    rustc_lexer::unescape::unescape_str(
+        inside_str,
+        &mut |_, unescaped_char| match unescaped_char {
+            Ok(c) => unescaped.push(c),
+            Err(_) => error = Err(()),
+        },
+    );
+    if error.is_err() {
+        return None;
+    }
     ctx.add_action(AssistId("make_raw_string"), "make raw string", |edit| {
         edit.target(literal.syntax().text_range());
-        edit.insert(literal.syntax().text_range().start(), "r");
+        let max_hash_streak = count_hashes(&unescaped);
+        let mut hashes = String::with_capacity(max_hash_streak + 1);
+        for _ in 0..hashes.capacity() {
+            hashes.push('#');
+        }
+        edit.replace(
+            literal.syntax().text_range(),
+            format!("r{}\"{}\"{}", hashes, unescaped, hashes),
+        );
     });
     ctx.build()
 }
 
+fn count_hashes(s: &str) -> usize {
+    let mut max_hash_streak = 0usize;
+    for idx in s.match_indices("\"#").map(|(i, _)| i) {
+        let (_, sub) = s.split_at(idx + 1);
+        let nb_hash = sub.chars().take_while(|c| *c == '#').count();
+        if nb_hash > max_hash_streak {
+            max_hash_streak = nb_hash;
+        }
+    }
+    max_hash_streak
+}
+
 fn find_usual_string_range(s: &str) -> Option<TextRange> {
     Some(TextRange::from_to(
         TextUnit::from(s.find('"')? as u32),
@@ -94,10 +133,10 @@ mod test {
             make_raw_string,
             r#"
             fn f() {
-                let s = <|>"random string";
+                let s = <|>"random\nstring";
             }
             "#,
-            r#""random string""#,
+            r#""random\nstring""#,
         );
     }
 
@@ -107,44 +146,69 @@ mod test {
             make_raw_string,
             r#"
             fn f() {
-                let s = <|>"random string";
+                let s = <|>"random\nstring";
             }
             "#,
-            r#"
+            r##"
             fn f() {
-                let s = <|>r"random string";
+                let s = <|>r#"random
+string"#;
             }
-            "#,
+            "##,
         )
     }
 
     #[test]
-    fn make_raw_string_with_escaped_works() {
+    fn make_raw_string_hashes_inside_works() {
         check_assist(
             make_raw_string,
-            r#"
+            r###"
             fn f() {
-                let s = <|>"random\nstring";
+                let s = <|>"#random##\nstring";
             }
-            "#,
-            r#"
+            "###,
+            r####"
             fn f() {
-                let s = <|>r"random\nstring";
+                let s = <|>r#"#random##
+string"#;
             }
-            "#,
+            "####,
         )
     }
 
     #[test]
-    fn make_raw_string_not_works() {
-        check_assist_not_applicable(
+    fn make_raw_string_closing_hashes_inside_works() {
+        check_assist(
+            make_raw_string,
+            r###"
+            fn f() {
+                let s = <|>"#random\"##\nstring";
+            }
+            "###,
+            r####"
+            fn f() {
+                let s = <|>r###"#random"##
+string"###;
+            }
+            "####,
+        )
+    }
+
+    #[test]
+    fn make_raw_string_nothing_to_unescape_works() {
+        check_assist(
             make_raw_string,
             r#"
             fn f() {
-                let s = <|>r"random string";
+                let s = <|>"random string";
             }
             "#,
-        );
+            r##"
+            fn f() {
+                let s = <|>r#"random string"#;
+            }
+            "##,
+        )
     }
 
     #[test]
@@ -369,4 +433,14 @@ mod test {
             "#,
         );
     }
+
+    #[test]
+    fn count_hashes_test() {
+        assert_eq!(0, count_hashes("abc"));
+        assert_eq!(0, count_hashes("###"));
+        assert_eq!(1, count_hashes("\"#abc"));
+        assert_eq!(0, count_hashes("#abc"));
+        assert_eq!(2, count_hashes("#ab\"##c"));
+        assert_eq!(4, count_hashes("#ab\"##\"####c"));
+    }
 }
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index d2376c475..ab77b46a9 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -108,6 +108,7 @@ mod assists {
     mod add_missing_impl_members;
     mod move_guard;
     mod move_bounds;
+    mod early_return;
 
     pub(crate) fn all<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assist>] {
         &[
@@ -135,6 +136,7 @@ mod assists {
             raw_string::make_raw_string,
             raw_string::make_usual_string,
             raw_string::remove_hash,
+            early_return::convert_to_guarded_return,
         ]
     }
 }
diff --git a/crates/ra_batch/Cargo.toml b/crates/ra_batch/Cargo.toml
index 62850746f..c85da7a2c 100644
--- a/crates/ra_batch/Cargo.toml
+++ b/crates/ra_batch/Cargo.toml
@@ -9,7 +9,7 @@ log = "0.4.5"
 rustc-hash = "1.0"
 crossbeam-channel = "0.3.5"
 
-ra_vfs = "0.4.0"
+ra_vfs = "0.5.0"
 ra_vfs_glob = { path = "../ra_vfs_glob" }
 ra_db = { path = "../ra_db" }
 ra_ide_api = { path = "../ra_ide_api" }
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index a5fc2a23e..df49eb13d 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -43,8 +43,12 @@ pub fn load_cargo(root: &Path) -> Result<(AnalysisHost, FxHashMap<SourceRootId,
     );
 
     // FIXME: cfg options?
-    let default_cfg_options =
-        get_rustc_cfg_options().atom("test".into()).atom("debug_assertion".into());
+    let default_cfg_options = {
+        let mut opts = get_rustc_cfg_options();
+        opts.insert_atom("test".into());
+        opts.insert_atom("debug_assertion".into());
+        opts
+    };
 
     let (crate_graph, _crate_names) =
         ws.to_crate_graph(&default_cfg_options, &mut |path: &Path| {
@@ -137,14 +141,8 @@ 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).unwrap();
-        let mut n_crates = 0;
-        for (root, _) in roots {
-            for _krate in Crate::source_root_crates(host.raw_database(), root) {
-                n_crates += 1;
-            }
-        }
-
+        let (host, _roots) = load_cargo(path).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/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs
index e1c92fbba..1bee3eb99 100644
--- a/crates/ra_cfg/src/lib.rs
+++ b/crates/ra_cfg/src/lib.rs
@@ -36,26 +36,20 @@ impl CfgOptions {
         self.check(&parse_cfg(attr))
     }
 
-    pub fn atom(mut self, name: SmolStr) -> CfgOptions {
-        self.atoms.insert(name);
-        self
+    pub fn insert_atom(&mut self, key: SmolStr) {
+        self.atoms.insert(key);
     }
 
-    pub fn key_value(mut self, key: SmolStr, value: SmolStr) -> CfgOptions {
-        self.key_values.insert((key, value));
-        self
+    pub fn remove_atom(&mut self, name: &str) {
+        self.atoms.remove(name);
     }
 
-    /// Shortcut to set features
-    pub fn features(mut self, iter: impl IntoIterator<Item = SmolStr>) -> CfgOptions {
-        for feat in iter {
-            self = self.key_value("feature".into(), feat);
-        }
-        self
+    pub fn insert_key_value(&mut self, key: SmolStr, value: SmolStr) {
+        self.key_values.insert((key, value));
     }
 
-    pub fn remove_atom(mut self, name: &SmolStr) -> CfgOptions {
-        self.atoms.remove(name);
-        self
+    /// Shortcut to set features
+    pub fn insert_features(&mut self, iter: impl IntoIterator<Item = SmolStr>) {
+        iter.into_iter().for_each(|feat| self.insert_key_value("feature".into(), feat));
     }
 }
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index 67e727a88..fcd102e8b 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 [dependencies]
 pico-args = "0.3.0"
 flexi_logger = "0.14.0"
-indicatif = "0.11.0"
+indicatif = "0.12.0"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_ide_api = { path = "../ra_ide_api" }
diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 727f1e62b..8bbe5d9e8 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -8,7 +8,7 @@ use std::{
 
 use ra_db::{
     salsa::{Database, Durability},
-    FileId, SourceDatabase,
+    FileId, SourceDatabaseExt,
 };
 use ra_ide_api::{Analysis, AnalysisChange, AnalysisHost, FilePosition, LineCol};
 
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index a8a110bd9..cda5cafb8 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -2,7 +2,7 @@
 
 use std::{collections::HashSet, fmt::Write, path::Path, time::Instant};
 
-use ra_db::SourceDatabase;
+use ra_db::SourceDatabaseExt;
 use ra_hir::{AssocItem, Crate, HasBodySource, HasSource, HirDisplay, ModuleDef, Ty, TypeWalk};
 use ra_syntax::AstNode;
 
@@ -22,16 +22,29 @@ pub fn run(
     let mut num_crates = 0;
     let mut visited_modules = HashSet::new();
     let mut visit_queue = Vec::new();
-    for (source_root_id, project_root) in roots {
-        if project_root.is_member() {
-            for krate in Crate::source_root_crates(db, source_root_id) {
-                num_crates += 1;
-                let module =
-                    krate.root_module(db).expect("crate in source root without root module");
-                visit_queue.push(module);
-            }
+
+    let members = roots
+        .into_iter()
+        .filter_map(
+            |(source_root_id, project_root)| {
+                if project_root.is_member() {
+                    Some(source_root_id)
+                } else {
+                    None
+                }
+            },
+        )
+        .collect::<HashSet<_>>();
+
+    for krate in Crate::all(db) {
+        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))) {
+            num_crates += 1;
+            visit_queue.push(module);
         }
     }
+
     println!("Crates in this dir: {}", num_crates);
     let mut num_decls = 0;
     let mut funcs = Vec::new();
@@ -130,7 +143,7 @@ pub fn run(
                         );
                         bar.println(format!(
                             "{} {}:{}-{}:{}: Expected {}, got {}",
-                            path.display(),
+                            path,
                             start.line + 1,
                             start.col_utf16,
                             end.line + 1,
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index c141f1a88..3394ae8ce 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -6,7 +6,7 @@ authors = ["rust-analyzer developers"]
 
 [dependencies]
 salsa = "0.13.0"
-relative-path = "0.4.0"
+relative-path = "1.0.0"
 rustc-hash = "1.0"
 
 ra_syntax = { path = "../ra_syntax" }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index 23148096c..eafa95921 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -48,9 +48,6 @@ impl SourceRoot {
     pub fn new_library() -> SourceRoot {
         SourceRoot { is_library: true, ..SourceRoot::new() }
     }
-    pub fn file_by_relative_path(&self, path: &RelativePath) -> Option<FileId> {
-        self.files.get(path).copied()
-    }
     pub fn insert_file(&mut self, path: RelativePathBuf, file_id: FileId) {
         self.files.insert(path, file_id);
     }
@@ -60,6 +57,9 @@ impl SourceRoot {
     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()
+    }
 }
 
 /// `CrateGraph` is a bit of information which turns a set of text files into a
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 603daed37..fc5d6d396 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -6,7 +6,7 @@ use std::{panic, sync::Arc};
 
 use ra_prof::profile;
 use ra_syntax::{ast, Parse, SourceFile, TextRange, TextUnit};
-use relative_path::RelativePathBuf;
+use relative_path::{RelativePath, RelativePathBuf};
 
 pub use crate::{
     cancellation::Canceled,
@@ -64,16 +64,39 @@ pub struct FileRange {
 
 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>>;
+}
+
 /// Database which stores all significant input facts: source code and project
 /// model. Everything else in rust-analyzer is derived from these queries.
 #[salsa::query_group(SourceDatabaseStorage)]
-pub trait SourceDatabase: CheckCanceled + std::fmt::Debug {
-    /// Text of the file.
-    #[salsa::input]
-    fn file_text(&self, file_id: FileId) -> Arc<String>;
+pub trait SourceDatabase: CheckCanceled + FileLoader + std::fmt::Debug {
     // Parses the file into the syntax tree.
     #[salsa::invoke(parse_query)]
     fn parse(&self, file_id: FileId) -> Parse<ast::SourceFile>;
+
+    /// The crate graph.
+    #[salsa::input]
+    fn crate_graph(&self) -> Arc<CrateGraph>;
+}
+
+fn parse_query(db: &impl SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
+    let _p = profile("parse_query");
+    let text = db.file_text(file_id);
+    SourceFile::parse(&*text)
+}
+
+/// We don't want to give HIR knowledge of source roots, hence we extract these
+/// methods into a separate DB.
+#[salsa::query_group(SourceDatabaseExtStorage)]
+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;
@@ -83,21 +106,48 @@ pub trait SourceDatabase: CheckCanceled + std::fmt::Debug {
     /// Contents of the source root.
     #[salsa::input]
     fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
+
     fn source_root_crates(&self, id: SourceRootId) -> Arc<Vec<CrateId>>;
-    /// The crate graph.
-    #[salsa::input]
-    fn crate_graph(&self) -> Arc<CrateGraph>;
 }
 
-fn source_root_crates(db: &impl SourceDatabase, id: SourceRootId) -> Arc<Vec<CrateId>> {
+fn source_root_crates(
+    db: &(impl SourceDatabaseExt + SourceDatabase),
+    id: SourceRootId,
+) -> Arc<Vec<CrateId>> {
     let root = db.source_root(id);
     let graph = db.crate_graph();
     let res = root.walk().filter_map(|it| graph.crate_id_for_crate_root(it)).collect::<Vec<_>>();
     Arc::new(res)
 }
 
-fn parse_query(db: &impl SourceDatabase, file_id: FileId) -> Parse<ast::SourceFile> {
-    let _p = profile("parse_query");
-    let text = db.file_text(file_id);
-    SourceFile::parse(&*text)
+/// Silly workaround for cyclic deps between the traits
+pub struct FileLoaderDelegate<T>(pub T);
+
+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);
+            // Workaround for relative path API: turn `lib.rs` into ``.
+            if !path.pop() {
+                path = RelativePathBuf::default();
+            }
+            path.push(relative_path);
+            path.normalize()
+        };
+        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)
+    }
+
+    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+        let source_root = self.0.file_source_root(file_id);
+        self.0.source_root_crates(source_root)
+    }
 }
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index cc117f84d..edf1fa49b 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -5,9 +5,9 @@ version = "0.1.0"
 authors = ["rust-analyzer developers"]
 
 [dependencies]
-arrayvec = "0.4.10"
+arrayvec = "0.5.1"
 log = "0.4.5"
-relative-path = "0.4.0"
+relative-path = "1.0.0"
 rustc-hash = "1.0"
 parking_lot = "0.9.0"
 ena = "0.13"
diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index 99d286215..3e9cd3c63 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -9,7 +9,7 @@ use ra_syntax::ast::{self, NameOwner, StructKind, TypeAscriptionOwner};
 use crate::{
     db::{AstDatabase, DefDatabase, HirDatabase},
     type_ref::TypeRef,
-    AsName, Enum, EnumVariant, FieldSource, HasSource, Name, Source, Struct, StructField,
+    AsName, Enum, EnumVariant, FieldSource, HasSource, Module, Name, Source, Struct, StructField,
 };
 
 impl Struct {
@@ -170,12 +170,20 @@ impl VariantDef {
         }
     }
 
-    pub(crate) fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
+    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
         match self {
             VariantDef::Struct(it) => it.field(db, name),
             VariantDef::EnumVariant(it) => it.field(db, name),
         }
     }
+
+    pub fn module(self, db: &impl HirDatabase) -> Module {
+        match self {
+            VariantDef::Struct(it) => it.module(db),
+            VariantDef::EnumVariant(it) => it.module(db),
+        }
+    }
+
     pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         match self {
             VariantDef::Struct(it) => it.variant_data(db),
diff --git a/crates/ra_hir/src/attr.rs b/crates/ra_hir/src/attr.rs
index f67e80bfd..bd159a566 100644
--- a/crates/ra_hir/src/attr.rs
+++ b/crates/ra_hir/src/attr.rs
@@ -63,14 +63,24 @@ impl Attr {
         self.path.as_ident().map_or(false, |s| s.to_string() == name)
     }
 
+    // FIXME: handle cfg_attr :-)
     pub(crate) fn as_cfg(&self) -> Option<&Subtree> {
-        if self.is_simple_atom("cfg") {
-            match &self.input {
-                Some(AttrInput::TokenTree(subtree)) => Some(subtree),
-                _ => None,
-            }
-        } else {
-            None
+        if !self.is_simple_atom("cfg") {
+            return None;
+        }
+        match &self.input {
+            Some(AttrInput::TokenTree(subtree)) => Some(subtree),
+            _ => None,
+        }
+    }
+
+    pub(crate) fn as_path(&self) -> Option<&SmolStr> {
+        if !self.is_simple_atom("path") {
+            return None;
+        }
+        match &self.input {
+            Some(AttrInput::Literal(it)) => Some(it),
+            _ => None,
         }
     }
 
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index e3a7e8e3c..8eb3c577d 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -5,7 +5,7 @@ pub(crate) mod docs;
 
 use std::sync::Arc;
 
-use ra_db::{CrateId, Edition, FileId, SourceRootId};
+use ra_db::{CrateId, Edition, FileId};
 use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
@@ -24,7 +24,7 @@ use crate::{
         U8, USIZE,
     },
     nameres::{CrateModuleId, ImportId, ModuleScope, Namespace},
-    resolve::{Resolver, TypeNs},
+    resolve::{Resolver, Scope, TypeNs},
     traits::TraitData,
     ty::{
         primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness},
@@ -76,10 +76,8 @@ impl Crate {
         crate_graph.edition(self.crate_id)
     }
 
-    // FIXME: should this be in source_binder?
-    pub fn source_root_crates(db: &impl DefDatabase, source_root: SourceRootId) -> Vec<Crate> {
-        let crate_ids = db.source_root_crates(source_root);
-        crate_ids.iter().map(|&crate_id| Crate { crate_id }).collect()
+    pub fn all(db: &impl DefDatabase) -> Vec<Crate> {
+        db.crate_graph().iter().map(|crate_id| Crate { crate_id }).collect()
     }
 }
 
@@ -465,7 +463,7 @@ impl Enum {
         // ...and add generic params, if present
         let p = self.generic_params(db);
         let r = if !p.params.is_empty() { r.push_generic_params_scope(p) } else { r };
-        r
+        r.push_scope(Scope::AdtScope(self.into()))
     }
 }
 
@@ -569,6 +567,14 @@ impl DefWithBody {
             DefWithBody::Static(s) => s.krate(db),
         }
     }
+
+    pub fn module(self, db: &impl HirDatabase) -> Module {
+        match self {
+            DefWithBody::Const(c) => c.module(db),
+            DefWithBody::Function(f) => f.module(db),
+            DefWithBody::Static(s) => s.module(db),
+        }
+    }
 }
 
 pub trait HasBody: Copy {
@@ -789,6 +795,20 @@ impl Const {
         ImplBlock::containing(module_impls, self.into())
     }
 
+    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
+        db.trait_items_index(self.module(db)).get_parent_trait(self.into())
+    }
+
+    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
+        if let Some(impl_block) = self.impl_block(db) {
+            Some(impl_block.into())
+        } else if let Some(trait_) = self.parent_trait(db) {
+            Some(trait_.into())
+        } else {
+            None
+        }
+    }
+
     // FIXME: move to a more general type for 'body-having' items
     /// Builds a resolver for code inside this item.
     pub(crate) fn resolver(self, db: &impl HirDatabase) -> Resolver {
@@ -1075,3 +1095,13 @@ impl From<AssocItem> for crate::generics::GenericDef {
         }
     }
 }
+
+impl AssocItem {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
+        match self {
+            AssocItem::Function(f) => f.module(db),
+            AssocItem::Const(c) => c.module(db),
+            AssocItem::TypeAlias(t) => t.module(db),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/code_model/docs.rs b/crates/ra_hir/src/code_model/docs.rs
index 9675e397f..8533b4f5e 100644
--- a/crates/ra_hir/src/code_model/docs.rs
+++ b/crates/ra_hir/src/code_model/docs.rs
@@ -6,21 +6,19 @@ use ra_syntax::ast;
 
 use crate::{
     db::{AstDatabase, DefDatabase, HirDatabase},
-    Const, Enum, EnumVariant, FieldSource, Function, HasSource, MacroDef, Module, Static, Struct,
-    StructField, Trait, TypeAlias, Union,
+    Adt, Const, Enum, EnumVariant, FieldSource, Function, HasSource, MacroDef, Module, Static,
+    Struct, StructField, Trait, TypeAlias, Union,
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum DocDef {
     Module(Module),
     StructField(StructField),
-    Struct(Struct),
-    Enum(Enum),
+    Adt(Adt),
     EnumVariant(EnumVariant),
     Static(Static),
     Const(Const),
     Function(Function),
-    Union(Union),
     Trait(Trait),
     TypeAlias(TypeAlias),
     MacroDef(MacroDef),
@@ -29,13 +27,11 @@ pub enum DocDef {
 impl_froms!(
     DocDef: Module,
     StructField,
-    Struct,
-    Enum,
+    Adt(Struct, Enum, Union),
     EnumVariant,
     Static,
     Const,
     Function,
-    Union,
     Trait,
     TypeAlias,
     MacroDef
@@ -79,13 +75,15 @@ pub(crate) fn documentation_query(
             FieldSource::Named(named) => docs_from_ast(&named),
             FieldSource::Pos(..) => None,
         },
-        DocDef::Struct(it) => docs_from_ast(&it.source(db).ast),
-        DocDef::Enum(it) => docs_from_ast(&it.source(db).ast),
+        DocDef::Adt(it) => match it {
+            Adt::Struct(it) => docs_from_ast(&it.source(db).ast),
+            Adt::Enum(it) => docs_from_ast(&it.source(db).ast),
+            Adt::Union(it) => docs_from_ast(&it.source(db).ast),
+        },
         DocDef::EnumVariant(it) => docs_from_ast(&it.source(db).ast),
         DocDef::Static(it) => docs_from_ast(&it.source(db).ast),
         DocDef::Const(it) => docs_from_ast(&it.source(db).ast),
         DocDef::Function(it) => docs_from_ast(&it.source(db).ast),
-        DocDef::Union(it) => docs_from_ast(&it.source(db).ast),
         DocDef::Trait(it) => docs_from_ast(&it.source(db).ast),
         DocDef::TypeAlias(it) => docs_from_ast(&it.source(db).ast),
         DocDef::MacroDef(it) => docs_from_ast(&it.source(db).ast),
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 73d7d6fb6..489a3b19c 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -111,37 +111,37 @@ pub trait DefDatabase: InternDatabase + HirDebugDatabase {
     #[salsa::invoke(CrateDefMap::crate_def_map_query)]
     fn crate_def_map(&self, krate: Crate) -> Arc<CrateDefMap>;
 
-    #[salsa::invoke(crate::impl_block::impls_in_module_with_source_map_query)]
+    #[salsa::invoke(ModuleImplBlocks::impls_in_module_with_source_map_query)]
     fn impls_in_module_with_source_map(
         &self,
         module: Module,
     ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>);
 
-    #[salsa::invoke(crate::impl_block::impls_in_module)]
+    #[salsa::invoke(ModuleImplBlocks::impls_in_module_query)]
     fn impls_in_module(&self, module: Module) -> Arc<ModuleImplBlocks>;
 
     #[salsa::invoke(crate::generics::GenericParams::generic_params_query)]
     fn generic_params(&self, def: GenericDef) -> Arc<GenericParams>;
 
-    #[salsa::invoke(crate::FnData::fn_data_query)]
+    #[salsa::invoke(FnData::fn_data_query)]
     fn fn_data(&self, func: Function) -> Arc<FnData>;
 
-    #[salsa::invoke(crate::type_alias::type_alias_data_query)]
+    #[salsa::invoke(TypeAliasData::type_alias_data_query)]
     fn type_alias_data(&self, typ: TypeAlias) -> Arc<TypeAliasData>;
 
-    #[salsa::invoke(crate::ConstData::const_data_query)]
+    #[salsa::invoke(ConstData::const_data_query)]
     fn const_data(&self, konst: Const) -> Arc<ConstData>;
 
-    #[salsa::invoke(crate::ConstData::static_data_query)]
+    #[salsa::invoke(ConstData::static_data_query)]
     fn static_data(&self, konst: Static) -> Arc<ConstData>;
 
-    #[salsa::invoke(crate::lang_item::LangItems::module_lang_items_query)]
+    #[salsa::invoke(LangItems::module_lang_items_query)]
     fn module_lang_items(&self, module: Module) -> Option<Arc<LangItems>>;
 
-    #[salsa::invoke(crate::lang_item::LangItems::crate_lang_items_query)]
+    #[salsa::invoke(LangItems::crate_lang_items_query)]
     fn crate_lang_items(&self, krate: Crate) -> Arc<LangItems>;
 
-    #[salsa::invoke(crate::lang_item::LangItems::lang_item_query)]
+    #[salsa::invoke(LangItems::lang_item_query)]
     fn lang_item(&self, start_crate: Crate, item: SmolStr) -> Option<LangItemTarget>;
 
     #[salsa::invoke(crate::code_model::docs::documentation_query)]
diff --git a/crates/ra_hir/src/debug.rs b/crates/ra_hir/src/debug.rs
index 87f3180c3..48b69000b 100644
--- a/crates/ra_hir/src/debug.rs
+++ b/crates/ra_hir/src/debug.rs
@@ -22,7 +22,7 @@ use std::fmt;
 
 use ra_db::{CrateId, FileId};
 
-use crate::{db::HirDatabase, Crate, Module, Name};
+use crate::{db::HirDatabase, Crate, HirFileId, Module, Name};
 
 impl Crate {
     pub fn debug(self, db: &impl HirDebugDatabase) -> impl fmt::Debug + '_ {
@@ -36,6 +36,12 @@ impl Module {
     }
 }
 
+impl HirFileId {
+    pub fn debug(self, db: &impl HirDebugDatabase) -> impl fmt::Debug + '_ {
+        debug_fn(move |fmt| db.debug_hir_file_id(self, fmt))
+    }
+}
+
 pub trait HirDebugHelper: HirDatabase {
     fn crate_name(&self, _krate: CrateId) -> Option<String> {
         None
@@ -48,6 +54,7 @@ pub trait HirDebugHelper: HirDatabase {
 pub trait HirDebugDatabase {
     fn debug_crate(&self, krate: Crate, fmt: &mut fmt::Formatter<'_>) -> fmt::Result;
     fn debug_module(&self, module: Module, fmt: &mut fmt::Formatter<'_>) -> fmt::Result;
+    fn debug_hir_file_id(&self, file_id: HirFileId, fmt: &mut fmt::Formatter<'_>) -> fmt::Result;
 }
 
 impl<DB: HirDebugHelper> HirDebugDatabase for DB {
@@ -62,12 +69,19 @@ impl<DB: HirDebugHelper> HirDebugDatabase for DB {
 
     fn debug_module(&self, module: Module, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let file_id = module.definition_source(self).file_id.original_file(self);
-        let path = self.file_path(file_id);
+        let path = self.file_path(file_id).unwrap_or_else(|| "N/A".to_string());
         fmt.debug_struct("Module")
             .field("name", &module.name(self).unwrap_or_else(Name::missing))
-            .field("path", &path.unwrap_or_else(|| "N/A".to_string()))
+            .field("path", &path)
             .finish()
     }
+
+    fn debug_hir_file_id(&self, file_id: HirFileId, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let original = file_id.original_file(self);
+        let path = self.file_path(original).unwrap_or_else(|| "N/A".to_string());
+        let is_macro = file_id != original.into();
+        fmt.debug_struct("HirFileId").field("path", &path).field("macro", &is_macro).finish()
+    }
 }
 
 fn debug_fn(f: impl Fn(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Debug {
diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index a012f33f7..f80d8eb5f 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -189,14 +189,14 @@ impl Module {
             ModuleSource::SourceFile(_) => None,
         };
 
-        let source_root_id = db.file_source_root(src.file_id.original_file(db));
-        db.source_root_crates(source_root_id).iter().map(|&crate_id| Crate { crate_id }).find_map(
-            |krate| {
+        db.relevant_crates(src.file_id.original_file(db))
+            .iter()
+            .map(|&crate_id| Crate { crate_id })
+            .find_map(|krate| {
                 let def_map = db.crate_def_map(krate);
                 let module_id = def_map.find_module_by_source(src.file_id, decl_id)?;
                 Some(Module { krate, module_id })
-            },
-        )
+            })
     }
 }
 
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index a3b65cc79..499dcafea 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -50,16 +50,6 @@ impl HirFileId {
         }
     }
 
-    /// XXX: this is a temporary function, which should go away when we implement the
-    /// nameresolution+macro expansion combo. Prefer using `original_file` if
-    /// possible.
-    pub fn as_original_file(self) -> FileId {
-        match self.0 {
-            HirFileIdRepr::File(file_id) => file_id,
-            HirFileIdRepr::Macro(_r) => panic!("macro generated file: {:?}", self),
-        }
-    }
-
     /// Get the crate which the macro lives in, if it is a macro file.
     pub(crate) fn macro_crate(self, db: &impl AstDatabase) -> Option<Crate> {
         match self.0 {
@@ -95,11 +85,7 @@ impl HirFileId {
                 // Note:
                 // The final goal we would like to make all parse_macro success,
                 // such that the following log will not call anyway.
-                log::warn!(
-                    "fail on macro_parse: (reason: {}) {}",
-                    err,
-                    macro_call_id.debug_dump(db)
-                );
+                log::warn!("fail on macro_parse: (reason: {})", err,);
             })
             .ok()?;
         match macro_file.macro_file_kind {
@@ -377,35 +363,6 @@ impl AstItemDef<ast::TypeAliasDef> for TypeAliasId {
     }
 }
 
-impl MacroCallId {
-    pub fn debug_dump(self, db: &impl AstDatabase) -> String {
-        let loc = self.loc(db);
-        let node = loc.ast_id.to_node(db);
-        let syntax_str = {
-            let mut res = String::new();
-            node.syntax().text().for_each_chunk(|chunk| {
-                if !res.is_empty() {
-                    res.push(' ')
-                }
-                res.push_str(chunk)
-            });
-            res
-        };
-
-        // dump the file name
-        let file_id: HirFileId = self.loc(db).ast_id.file_id();
-        let original = file_id.original_file(db);
-        let macro_rules = db.macro_def(loc.def);
-
-        format!(
-            "macro call [file: {:?}] : {}\nhas rules: {}",
-            db.file_relative_path(original),
-            syntax_str,
-            macro_rules.is_some()
-        )
-    }
-}
-
 /// 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.
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 55dfc393b..33ef87563 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -176,6 +176,25 @@ pub struct ModuleImplBlocks {
 }
 
 impl ModuleImplBlocks {
+    pub(crate) fn impls_in_module_with_source_map_query(
+        db: &(impl DefDatabase + AstDatabase),
+        module: Module,
+    ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
+        let mut source_map = ImplSourceMap::default();
+        let crate_graph = db.crate_graph();
+        let cfg_options = crate_graph.cfg_options(module.krate.crate_id());
+
+        let result = ModuleImplBlocks::collect(db, cfg_options, module, &mut source_map);
+        (Arc::new(result), Arc::new(source_map))
+    }
+
+    pub(crate) fn impls_in_module_query(
+        db: &impl DefDatabase,
+        module: Module,
+    ) -> Arc<ModuleImplBlocks> {
+        db.impls_in_module_with_source_map(module).0
+    }
+
     fn collect(
         db: &(impl DefDatabase + AstDatabase),
         cfg_options: &CfgOptions,
@@ -264,19 +283,3 @@ impl ModuleImplBlocks {
         }
     }
 }
-
-pub(crate) fn impls_in_module_with_source_map_query(
-    db: &(impl DefDatabase + AstDatabase),
-    module: Module,
-) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
-    let mut source_map = ImplSourceMap::default();
-    let crate_graph = db.crate_graph();
-    let cfg_options = crate_graph.cfg_options(module.krate.crate_id());
-
-    let result = ModuleImplBlocks::collect(db, cfg_options, module, &mut source_map);
-    (Arc::new(result), Arc::new(source_map))
-}
-
-pub(crate) fn impls_in_module(db: &impl DefDatabase, module: Module) -> Arc<ModuleImplBlocks> {
-    db.impls_in_module_with_source_map(module).0
-}
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 4340e9d34..ca261e8f5 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -51,6 +51,7 @@ mod lang_item;
 mod generics;
 mod resolve;
 pub mod diagnostics;
+mod util;
 
 mod code_model;
 
@@ -71,7 +72,7 @@ pub use self::{
     either::Either,
     expr::ExprScopes,
     from_source::FromSource,
-    generics::{GenericParam, GenericParams, HasGenericParams},
+    generics::{GenericDef, GenericParam, GenericParams, HasGenericParams},
     ids::{HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroFile},
     impl_block::ImplBlock,
     name::Name,
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index f750986b8..0b278deb3 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -5,10 +5,10 @@ use std::{panic, sync::Arc};
 use parking_lot::Mutex;
 use ra_cfg::CfgOptions;
 use ra_db::{
-    salsa, CrateGraph, CrateId, Edition, FileId, FilePosition, SourceDatabase, SourceRoot,
-    SourceRootId,
+    salsa, CrateGraph, CrateId, Edition, FileId, FileLoader, FileLoaderDelegate, FilePosition,
+    SourceDatabase, SourceDatabaseExt, SourceRoot, SourceRootId,
 };
-use relative_path::RelativePathBuf;
+use relative_path::{RelativePath, RelativePathBuf};
 use rustc_hash::FxHashMap;
 use test_utils::{extract_offset, parse_fixture, CURSOR_MARKER};
 
@@ -17,6 +17,7 @@ use crate::{db, debug::HirDebugHelper, diagnostics::DiagnosticSink};
 pub const WORKSPACE: SourceRootId = SourceRootId(0);
 
 #[salsa::database(
+    ra_db::SourceDatabaseExtStorage,
     ra_db::SourceDatabaseStorage,
     db::InternDatabaseStorage,
     db::AstDatabaseStorage,
@@ -34,6 +35,22 @@ pub struct MockDatabase {
 
 impl panic::RefUnwindSafe for MockDatabase {}
 
+impl FileLoader for MockDatabase {
+    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 relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+        FileLoaderDelegate(self).relevant_crates(file_id)
+    }
+}
+
 impl HirDebugHelper for MockDatabase {
     fn crate_name(&self, krate: CrateId) -> Option<String> {
         self.crate_names.get(&krate).cloned()
@@ -278,7 +295,10 @@ macro_rules! crate_graph {
             $crate_path:literal,
             $($edition:literal,)?
             [$($dep:literal),*]
-            $(,$cfg:expr)?
+            $(, cfg = {
+                $($key:literal $(= $value:literal)?),*
+                $(,)?
+            })?
         ),
     )*) => {{
         let mut res = $crate::mock::CrateGraphFixture::default();
@@ -286,7 +306,19 @@ macro_rules! crate_graph {
             #[allow(unused_mut, unused_assignments)]
             let mut edition = ra_db::Edition::Edition2018;
             $(edition = ra_db::Edition::from_string($edition);)?
-            let cfg_options = { ::ra_cfg::CfgOptions::default() $(; $cfg)? };
+            let cfg_options = {
+                #[allow(unused_mut)]
+                let mut cfg = ::ra_cfg::CfgOptions::default();
+                $(
+                    $(
+                        if 0 == 0 $(+ { drop($value); 1})? {
+                            cfg.insert_atom($key.into());
+                        }
+                        $(cfg.insert_key_value($key.into(), $value.into());)?
+                    )*
+                )?
+                cfg
+            };
             res.0.push((
                 $crate_name.to_string(),
                 ($crate_path.to_string(), edition, cfg_options, vec![$($dep.to_string()),*])
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index cef2dc9d2..b5fe16bfa 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -7,14 +7,13 @@ use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
+    attr::Attr,
     db::DefDatabase,
     ids::{AstItemDef, LocationCtx, MacroCallId, MacroCallLoc, MacroDefId, MacroFileKind},
     name::MACRO_RULES,
     nameres::{
-        diagnostics::DefDiagnostic,
-        mod_resolution::{resolve_submodule, ParentModule},
-        raw, Crate, CrateDefMap, CrateModuleId, ModuleData, ModuleDef, PerNs, ReachedFixedPoint,
-        Resolution, ResolveMode,
+        diagnostics::DefDiagnostic, mod_resolution::ModDir, raw, Crate, CrateDefMap, CrateModuleId,
+        ModuleData, ModuleDef, PerNs, ReachedFixedPoint, Resolution, ResolveMode,
     },
     Adt, AstId, Const, Enum, Function, HirFileId, MacroDef, Module, Name, Path, PathKind, Static,
     Struct, Trait, TypeAlias, Union,
@@ -45,6 +44,7 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         glob_imports: FxHashMap::default(),
         unresolved_imports: Vec::new(),
         unexpanded_macros: Vec::new(),
+        mod_dirs: FxHashMap::default(),
         macro_stack_monitor: MacroStackMonitor::default(),
         cfg_options,
     };
@@ -87,6 +87,7 @@ struct DefCollector<'a, DB> {
     glob_imports: FxHashMap<CrateModuleId, Vec<(CrateModuleId, raw::ImportId)>>,
     unresolved_imports: Vec<(CrateModuleId, raw::ImportId, raw::ImportData)>,
     unexpanded_macros: Vec<(CrateModuleId, AstId<ast::MacroCall>, Path)>,
+    mod_dirs: FxHashMap<CrateModuleId, ModDir>,
 
     /// Some macro use `$tt:tt which mean we have to handle the macro perfectly
     /// To prevent stack overflow, we add a deep counter here for prevent that.
@@ -107,11 +108,10 @@ where
         self.def_map.modules[module_id].definition = Some(file_id);
         ModCollector {
             def_collector: &mut *self,
-            attr_path: None,
             module_id,
             file_id: file_id.into(),
             raw_items: &raw_items,
-            parent_module: None,
+            mod_dir: ModDir::root(),
         }
         .collect(raw_items.items());
 
@@ -481,13 +481,13 @@ where
         if !self.macro_stack_monitor.is_poison(macro_def_id) {
             let file_id: HirFileId = macro_call_id.as_file(MacroFileKind::Items);
             let raw_items = self.db.raw_items(file_id);
+            let mod_dir = self.mod_dirs[&module_id].clone();
             ModCollector {
                 def_collector: &mut *self,
                 file_id,
-                attr_path: None,
                 module_id,
                 raw_items: &raw_items,
-                parent_module: None,
+                mod_dir,
             }
             .collect(raw_items.items());
         } else {
@@ -508,9 +508,8 @@ struct ModCollector<'a, D> {
     def_collector: D,
     module_id: CrateModuleId,
     file_id: HirFileId,
-    attr_path: Option<&'a SmolStr>,
     raw_items: &'a raw::RawItems,
-    parent_module: Option<ParentModule<'a>>,
+    mod_dir: ModDir,
 }
 
 impl<DB> ModCollector<'_, &'_ mut DefCollector<'_, DB>>
@@ -518,6 +517,10 @@ where
     DB: DefDatabase,
 {
     fn collect(&mut self, items: &[raw::RawItem]) {
+        // 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());
+
         // Prelude module is always considered to be `#[macro_use]`.
         if let Some(prelude_module) = self.def_collector.def_map.prelude {
             if prelude_module.krate != self.def_collector.def_map.krate {
@@ -530,7 +533,7 @@ where
         // `#[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 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 {
@@ -541,9 +544,11 @@ where
         }
 
         for item in items {
-            if self.is_cfg_enabled(&item.attrs) {
+            if self.is_cfg_enabled(item.attrs()) {
                 match item.kind {
-                    raw::RawItemKind::Module(m) => self.collect_module(&self.raw_items[m]),
+                    raw::RawItemKind::Module(m) => {
+                        self.collect_module(&self.raw_items[m], item.attrs())
+                    }
                     raw::RawItemKind::Import(import_id) => self
                         .def_collector
                         .unresolved_imports
@@ -555,53 +560,48 @@ where
         }
     }
 
-    fn collect_module(&mut self, module: &raw::ModuleData) {
+    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &[Attr]) {
+        let path_attr = self.path_attr(attrs);
+        let is_macro_use = self.is_macro_use(attrs);
         match module {
             // inline module, just recurse
-            raw::ModuleData::Definition { name, items, ast_id, attr_path, is_macro_use } => {
+            raw::ModuleData::Definition { name, items, ast_id } => {
                 let module_id =
                     self.push_child_module(name.clone(), ast_id.with_file_id(self.file_id), None);
-                let parent_module = ParentModule { name, attr_path: attr_path.as_ref() };
 
                 ModCollector {
                     def_collector: &mut *self.def_collector,
                     module_id,
-                    attr_path: attr_path.as_ref(),
                     file_id: self.file_id,
                     raw_items: self.raw_items,
-                    parent_module: Some(parent_module),
+                    mod_dir: self.mod_dir.descend_into_definition(name, path_attr),
                 }
                 .collect(&*items);
-                if *is_macro_use {
+                if is_macro_use {
                     self.import_all_legacy_macros(module_id);
                 }
             }
             // out of line module, resolve, parse and recurse
-            raw::ModuleData::Declaration { name, ast_id, attr_path, is_macro_use } => {
+            raw::ModuleData::Declaration { name, ast_id } => {
                 let ast_id = ast_id.with_file_id(self.file_id);
-                let is_root = self.def_collector.def_map.modules[self.module_id].parent.is_none();
-                match resolve_submodule(
+                match self.mod_dir.resolve_declaration(
                     self.def_collector.db,
                     self.file_id,
-                    self.attr_path,
                     name,
-                    is_root,
-                    attr_path.as_ref(),
-                    self.parent_module,
+                    path_attr,
                 ) {
-                    Ok(file_id) => {
+                    Ok((file_id, mod_dir)) => {
                         let module_id = self.push_child_module(name.clone(), ast_id, Some(file_id));
                         let raw_items = self.def_collector.db.raw_items(file_id.into());
                         ModCollector {
                             def_collector: &mut *self.def_collector,
                             module_id,
-                            attr_path: attr_path.as_ref(),
                             file_id: file_id.into(),
                             raw_items: &raw_items,
-                            parent_module: None,
+                            mod_dir,
                         }
                         .collect(raw_items.items());
-                        if *is_macro_use {
+                        if is_macro_use {
                             self.import_all_legacy_macros(module_id);
                         }
                     }
@@ -714,12 +714,16 @@ where
         }
     }
 
-    fn is_cfg_enabled(&self, attrs: &raw::Attrs) -> bool {
-        attrs.as_ref().map_or(true, |attrs| {
-            attrs
-                .iter()
-                .all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
-        })
+    fn is_cfg_enabled(&self, attrs: &[Attr]) -> bool {
+        attrs.iter().all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
+    }
+
+    fn path_attr<'a>(&self, attrs: &'a [Attr]) -> Option<&'a SmolStr> {
+        attrs.iter().find_map(|attr| attr.as_path())
+    }
+
+    fn is_macro_use<'a>(&self, attrs: &'a [Attr]) -> bool {
+        attrs.iter().any(|attr| attr.is_simple_atom("macro_use"))
     }
 }
 
@@ -747,6 +751,7 @@ mod tests {
             glob_imports: FxHashMap::default(),
             unresolved_imports: Vec::new(),
             unexpanded_macros: Vec::new(),
+            mod_dirs: FxHashMap::default(),
             macro_stack_monitor: monitor,
             cfg_options: &CfgOptions::default(),
         };
diff --git a/crates/ra_hir/src/nameres/mod_resolution.rs b/crates/ra_hir/src/nameres/mod_resolution.rs
index 3aa32bd66..e8b808514 100644
--- a/crates/ra_hir/src/nameres/mod_resolution.rs
+++ b/crates/ra_hir/src/nameres/mod_resolution.rs
@@ -1,187 +1,87 @@
 //! This module resolves `mod foo;` declaration to file.
-
-use std::{borrow::Cow, sync::Arc};
-
-use ra_db::{FileId, SourceRoot};
+use ra_db::FileId;
 use ra_syntax::SmolStr;
 use relative_path::RelativePathBuf;
 
 use crate::{db::DefDatabase, HirFileId, Name};
 
-#[derive(Clone, Copy)]
-pub(super) struct ParentModule<'a> {
-    pub(super) name: &'a Name,
-    pub(super) attr_path: Option<&'a SmolStr>,
+#[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,
+    /// inside `./foo.rs`, mods with `#[path]` should *not* be relative to `./foo/`
+    root_non_dir_owner: bool,
 }
 
-impl<'a> ParentModule<'a> {
-    fn attribute_path(&self) -> Option<&SmolStr> {
-        self.attr_path.filter(|p| !p.is_empty())
+impl ModDir {
+    pub(super) fn root() -> ModDir {
+        ModDir { path: RelativePathBuf::default(), root_non_dir_owner: false }
     }
-}
 
-pub(super) fn resolve_submodule(
-    db: &impl DefDatabase,
-    file_id: HirFileId,
-    mod_attr_path: Option<&SmolStr>,
-    name: &Name,
-    is_root: bool,
-    attr_path: Option<&SmolStr>,
-    parent_module: Option<ParentModule<'_>>,
-) -> Result<FileId, RelativePathBuf> {
-    let file_id = file_id.original_file(db);
-    let source_root_id = db.file_source_root(file_id);
-    let path = db.file_relative_path(file_id);
-    let root = RelativePathBuf::default();
-    let dir_path = path.parent().unwrap_or(&root);
-    let mod_name = path.file_stem().unwrap_or("unknown");
-
-    let resolve_mode = match (attr_path.filter(|p| !p.is_empty()), parent_module) {
-        (Some(file_path), Some(parent_module)) => {
-            let file_path = normalize_attribute_path(file_path);
-            match parent_module.attribute_path() {
-                Some(parent_module_attr_path) => {
-                    let path = dir_path
-                        .join(format!(
-                            "{}/{}",
-                            normalize_attribute_path(parent_module_attr_path),
-                            file_path
-                        ))
-                        .normalize();
-                    ResolutionMode::InlineModuleWithAttributePath(
-                        InsideInlineModuleMode::WithAttributePath(path),
-                    )
-                }
-                None => {
-                    let path =
-                        dir_path.join(format!("{}/{}", parent_module.name, file_path)).normalize();
-                    ResolutionMode::InsideInlineModule(InsideInlineModuleMode::WithAttributePath(
-                        path,
-                    ))
+    pub(super) fn descend_into_definition(
+        &self,
+        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()),
+            Some(attr_path) => {
+                if self.root_non_dir_owner {
+                    // Workaround for relative path API: turn `lib.rs` into ``.
+                    if !path.pop() {
+                        path = RelativePathBuf::default();
+                    }
                 }
+                path.push(attr_path);
             }
         }
-        (None, Some(parent_module)) => match parent_module.attribute_path() {
-            Some(parent_module_attr_path) => {
-                let path = dir_path.join(format!(
-                    "{}/{}.rs",
-                    normalize_attribute_path(parent_module_attr_path),
-                    name
-                ));
-                ResolutionMode::InlineModuleWithAttributePath(InsideInlineModuleMode::File(path))
+        ModDir { path, root_non_dir_owner: false }
+    }
+
+    pub(super) fn resolve_declaration(
+        &self,
+        db: &impl DefDatabase,
+        file_id: HirFileId,
+        name: &Name,
+        attr_path: Option<&SmolStr>,
+    ) -> Result<(FileId, ModDir), RelativePathBuf> {
+        let empty_path = RelativePathBuf::default();
+        let file_id = file_id.original_file(db);
+
+        let mut candidate_files = Vec::new();
+        match attr_to_path(attr_path) {
+            Some(attr_path) => {
+                let base = if self.root_non_dir_owner {
+                    self.path.parent().unwrap_or(&empty_path)
+                } else {
+                    &self.path
+                };
+                candidate_files.push(base.join(attr_path))
             }
             None => {
-                let path = dir_path.join(format!("{}/{}.rs", parent_module.name, name));
-                ResolutionMode::InsideInlineModule(InsideInlineModuleMode::File(path))
-            }
-        },
-        (Some(file_path), None) => {
-            let file_path = normalize_attribute_path(file_path);
-            let path = dir_path.join(file_path.as_ref()).normalize();
-            ResolutionMode::OutOfLine(OutOfLineMode::WithAttributePath(path))
-        }
-        (None, None) => {
-            let is_dir_owner = is_root || mod_name == "mod" || mod_attr_path.is_some();
-            if is_dir_owner {
-                let file_mod = dir_path.join(format!("{}.rs", name));
-                let dir_mod = dir_path.join(format!("{}/mod.rs", name));
-                ResolutionMode::OutOfLine(OutOfLineMode::RootOrModRs {
-                    file: file_mod,
-                    directory: dir_mod,
-                })
-            } else {
-                let path = dir_path.join(format!("{}/{}.rs", mod_name, name));
-                ResolutionMode::OutOfLine(OutOfLineMode::FileInDirectory(path))
+                candidate_files.push(self.path.join(&format!("{}.rs", name)));
+                candidate_files.push(self.path.join(&format!("{}/mod.rs", name)));
             }
-        }
-    };
-
-    resolve_mode.resolve(db.source_root(source_root_id))
-}
-
-fn normalize_attribute_path(file_path: &SmolStr) -> Cow<str> {
-    let current_dir = "./";
-    let windows_path_separator = r#"\"#;
-    let current_dir_normalize = if file_path.starts_with(current_dir) {
-        &file_path[current_dir.len()..]
-    } else {
-        file_path.as_str()
-    };
-    if current_dir_normalize.contains(windows_path_separator) {
-        Cow::Owned(current_dir_normalize.replace(windows_path_separator, "/"))
-    } else {
-        Cow::Borrowed(current_dir_normalize)
-    }
-}
-
-enum OutOfLineMode {
-    RootOrModRs { file: RelativePathBuf, directory: RelativePathBuf },
-    FileInDirectory(RelativePathBuf),
-    WithAttributePath(RelativePathBuf),
-}
-
-impl OutOfLineMode {
-    pub fn resolve(&self, source_root: Arc<SourceRoot>) -> Result<FileId, RelativePathBuf> {
-        match self {
-            OutOfLineMode::RootOrModRs { file, directory } => {
-                match source_root.file_by_relative_path(file) {
-                    None => resolve_simple_path(source_root, directory).map_err(|_| file.clone()),
-                    file_id => resolve_find_result(file_id, file),
+        };
+
+        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 }));
             }
-            OutOfLineMode::FileInDirectory(path) => resolve_simple_path(source_root, path),
-            OutOfLineMode::WithAttributePath(path) => resolve_simple_path(source_root, path),
         }
+        Err(candidate_files.remove(0))
     }
 }
 
-enum InsideInlineModuleMode {
-    File(RelativePathBuf),
-    WithAttributePath(RelativePathBuf),
-}
-
-impl InsideInlineModuleMode {
-    pub fn resolve(&self, source_root: Arc<SourceRoot>) -> Result<FileId, RelativePathBuf> {
-        match self {
-            InsideInlineModuleMode::File(path) => resolve_simple_path(source_root, path),
-            InsideInlineModuleMode::WithAttributePath(path) => {
-                resolve_simple_path(source_root, path)
-            }
-        }
-    }
-}
-
-enum ResolutionMode {
-    OutOfLine(OutOfLineMode),
-    InsideInlineModule(InsideInlineModuleMode),
-    InlineModuleWithAttributePath(InsideInlineModuleMode),
-}
-
-impl ResolutionMode {
-    pub fn resolve(&self, source_root: Arc<SourceRoot>) -> Result<FileId, RelativePathBuf> {
-        use self::ResolutionMode::*;
-
-        match self {
-            OutOfLine(mode) => mode.resolve(source_root),
-            InsideInlineModule(mode) => mode.resolve(source_root),
-            InlineModuleWithAttributePath(mode) => mode.resolve(source_root),
-        }
-    }
-}
-
-fn resolve_simple_path(
-    source_root: Arc<SourceRoot>,
-    path: &RelativePathBuf,
-) -> Result<FileId, RelativePathBuf> {
-    resolve_find_result(source_root.file_by_relative_path(path), path)
-}
-
-fn resolve_find_result(
-    file_id: Option<FileId>,
-    path: &RelativePathBuf,
-) -> Result<FileId, RelativePathBuf> {
-    match file_id {
-        Some(file_id) => Ok(file_id.clone()),
-        None => Err(path.clone()),
-    }
+fn attr_to_path(attr: Option<&SmolStr>) -> Option<RelativePathBuf> {
+    attr.and_then(|it| RelativePathBuf::from_path(&it.replace("\\", "/")).ok())
 }
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 623b343c4..57f2929c3 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -5,7 +5,7 @@ use std::{ops::Index, sync::Arc};
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
-    AstNode, AstPtr, SmolStr, SourceFile,
+    AstNode, AstPtr, SourceFile,
 };
 use test_utils::tested_by;
 
@@ -121,14 +121,20 @@ impl Index<Macro> for RawItems {
 }
 
 // Avoid heap allocation on items without attributes.
-pub(super) type Attrs = Option<Arc<[Attr]>>;
+type Attrs = Option<Arc<[Attr]>>;
 
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub(super) struct RawItem {
-    pub(super) attrs: Attrs,
+    attrs: Attrs,
     pub(super) kind: RawItemKind,
 }
 
+impl RawItem {
+    pub(super) fn attrs(&self) -> &[Attr] {
+        self.attrs.as_ref().map_or(&[], |it| &*it)
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub(super) enum RawItemKind {
     Module(Module),
@@ -143,19 +149,8 @@ impl_arena_id!(Module);
 
 #[derive(Debug, PartialEq, Eq)]
 pub(super) enum ModuleData {
-    Declaration {
-        name: Name,
-        ast_id: FileAstId<ast::Module>,
-        attr_path: Option<SmolStr>,
-        is_macro_use: bool,
-    },
-    Definition {
-        name: Name,
-        ast_id: FileAstId<ast::Module>,
-        items: Vec<RawItem>,
-        attr_path: Option<SmolStr>,
-        is_macro_use: bool,
-    },
+    Declaration { name: Name, ast_id: FileAstId<ast::Module> },
+    Definition { name: Name, ast_id: FileAstId<ast::Module>, items: Vec<RawItem> },
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -286,28 +281,17 @@ impl<DB: AstDatabase> RawItemsCollector<&DB> {
         let attrs = self.parse_attrs(&module);
 
         let ast_id = self.source_ast_id_map.ast_id(&module);
-        // FIXME: cfg_attr
-        let is_macro_use = module.has_atom_attr("macro_use");
         if module.has_semi() {
-            let attr_path = extract_mod_path_attribute(&module);
-            let item = self.raw_items.modules.alloc(ModuleData::Declaration {
-                name,
-                ast_id,
-                attr_path,
-                is_macro_use,
-            });
+            let item = self.raw_items.modules.alloc(ModuleData::Declaration { name, ast_id });
             self.push_item(current_module, attrs, RawItemKind::Module(item));
             return;
         }
 
         if let Some(item_list) = module.item_list() {
-            let attr_path = extract_mod_path_attribute(&module);
             let item = self.raw_items.modules.alloc(ModuleData::Definition {
                 name,
                 ast_id,
                 items: Vec::new(),
-                attr_path,
-                is_macro_use,
             });
             self.process_module(Some(item), item_list);
             self.push_item(current_module, attrs, RawItemKind::Module(item));
@@ -417,16 +401,3 @@ impl<DB: AstDatabase> RawItemsCollector<&DB> {
         Attr::from_attrs_owner(self.file_id, item, self.db)
     }
 }
-
-fn extract_mod_path_attribute(module: &ast::Module) -> Option<SmolStr> {
-    module.attrs().into_iter().find_map(|attr| {
-        attr.as_simple_key_value().and_then(|(name, value)| {
-            let is_path = name == "path";
-            if is_path {
-                Some(value)
-            } else {
-                None
-            }
-        })
-    })
-}
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index 34dd79574..8c6b40aaf 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -7,7 +7,6 @@ mod mod_resolution;
 use std::sync::Arc;
 
 use insta::assert_snapshot;
-use ra_cfg::CfgOptions;
 use ra_db::SourceDatabase;
 use test_utils::covers;
 
@@ -561,12 +560,12 @@ fn cfg_test() {
         "#,
         crate_graph! {
             "main": ("/main.rs", ["std"]),
-            "std": ("/lib.rs", [], CfgOptions::default()
-                .atom("test".into())
-                .key_value("feature".into(), "foo".into())
-                .key_value("feature".into(), "bar".into())
-                .key_value("opt".into(), "42".into())
-            ),
+            "std": ("/lib.rs", [], cfg = {
+                "test",
+                "feature" = "foo",
+                "feature" = "bar",
+                "opt" = "42",
+            }),
         },
     );
 
diff --git a/crates/ra_hir/src/nameres/tests/incremental.rs b/crates/ra_hir/src/nameres/tests/incremental.rs
index c41862a0b..af9c39760 100644
--- a/crates/ra_hir/src/nameres/tests/incremental.rs
+++ b/crates/ra_hir/src/nameres/tests/incremental.rs
@@ -2,7 +2,7 @@ use super::*;
 
 use std::sync::Arc;
 
-use ra_db::SourceDatabase;
+use ra_db::{SourceDatabase, SourceDatabaseExt};
 
 fn check_def_map_is_not_recomputed(initial: &str, file_change: &str) {
     let (mut db, pos) = MockDatabase::with_position(initial);
diff --git a/crates/ra_hir/src/nameres/tests/macros.rs b/crates/ra_hir/src/nameres/tests/macros.rs
index e4b408394..4f52ad2c5 100644
--- a/crates/ra_hir/src/nameres/tests/macros.rs
+++ b/crates/ra_hir/src/nameres/tests/macros.rs
@@ -38,21 +38,34 @@ fn macro_rules_can_define_modules() {
         }
         m!(n1);
 
+        mod m {
+            m!(n3)
+        }
+
         //- /n1.rs
         m!(n2)
         //- /n1/n2.rs
         struct X;
+        //- /m/n3.rs
+        struct Y;
         ",
     );
     assert_snapshot!(map, @r###"
-   ⋮crate
-   ⋮n1: t
-   ⋮
-   ⋮crate::n1
-   ⋮n2: t
-   ⋮
-   ⋮crate::n1::n2
-   ⋮X: t v
+    crate
+    m: t
+    n1: t
+    
+    crate::m
+    n3: t
+    
+    crate::m::n3
+    Y: t v
+    
+    crate::n1
+    n2: t
+    
+    crate::n1::n2
+    X: t v
     "###);
 }
 
diff --git a/crates/ra_hir/src/nameres/tests/mod_resolution.rs b/crates/ra_hir/src/nameres/tests/mod_resolution.rs
index e3e6f1e95..f569aacdc 100644
--- a/crates/ra_hir/src/nameres/tests/mod_resolution.rs
+++ b/crates/ra_hir/src/nameres/tests/mod_resolution.rs
@@ -26,6 +26,33 @@ fn name_res_works_for_broken_modules() {
 }
 
 #[test]
+fn nested_module_resolution() {
+    let map = def_map(
+        "
+        //- /lib.rs
+        mod n1;
+
+        //- /n1.rs
+        mod n2;
+
+        //- /n1/n2.rs
+        struct X;
+        ",
+    );
+
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮n1: t
+        ⋮
+        ⋮crate::n1
+        ⋮n2: t
+        ⋮
+        ⋮crate::n1::n2
+        ⋮X: t v
+    "###);
+}
+
+#[test]
 fn module_resolution_works_for_non_standard_filenames() {
     let map = def_map_with_crate_graph(
         "
@@ -53,18 +80,15 @@ fn module_resolution_works_for_non_standard_filenames() {
 
 #[test]
 fn module_resolution_works_for_raw_modules() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         "
-        //- /library.rs
+        //- /lib.rs
         mod r#async;
         use self::r#async::Bar;
 
         //- /async.rs
         pub struct Bar;
         ",
-        crate_graph! {
-            "library": ("/library.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -79,9 +103,9 @@ fn module_resolution_works_for_raw_modules() {
 
 #[test]
 fn module_resolution_decl_path() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
-        //- /library.rs
+        //- /lib.rs
         #[path = "bar/baz/foo.rs"]
         mod foo;
         use self::foo::Bar;
@@ -89,9 +113,6 @@ fn module_resolution_decl_path() {
         //- /bar/baz/foo.rs
         pub struct Bar;
         "###,
-        crate_graph! {
-            "library": ("/library.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -106,7 +127,7 @@ fn module_resolution_decl_path() {
 
 #[test]
 fn module_resolution_module_with_path_in_mod_rs() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -120,9 +141,6 @@ fn module_resolution_module_with_path_in_mod_rs() {
         //- /foo/baz.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -140,7 +158,7 @@ fn module_resolution_module_with_path_in_mod_rs() {
 
 #[test]
 fn module_resolution_module_with_path_non_crate_root() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -154,9 +172,6 @@ fn module_resolution_module_with_path_non_crate_root() {
         //- /baz.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -174,7 +189,7 @@ fn module_resolution_module_with_path_non_crate_root() {
 
 #[test]
 fn module_resolution_module_decl_path_super() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "bar/baz/module.rs"]
@@ -184,9 +199,6 @@ fn module_resolution_module_decl_path_super() {
         //- /bar/baz/module.rs
         use super::Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -201,7 +213,7 @@ fn module_resolution_module_decl_path_super() {
 
 #[test]
 fn module_resolution_explicit_path_mod_rs() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "module/mod.rs"]
@@ -210,9 +222,6 @@ fn module_resolution_explicit_path_mod_rs() {
         //- /module/mod.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -226,7 +235,7 @@ fn module_resolution_explicit_path_mod_rs() {
 
 #[test]
 fn module_resolution_relative_path() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -238,9 +247,6 @@ fn module_resolution_relative_path() {
         //- /sub.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -257,7 +263,7 @@ fn module_resolution_relative_path() {
 
 #[test]
 fn module_resolution_relative_path_2() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -269,9 +275,6 @@ fn module_resolution_relative_path_2() {
         //- /sub.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -288,7 +291,7 @@ fn module_resolution_relative_path_2() {
 
 #[test]
 fn module_resolution_explicit_path_mod_rs_2() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "module/bar/mod.rs"]
@@ -297,9 +300,6 @@ fn module_resolution_explicit_path_mod_rs_2() {
         //- /module/bar/mod.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -313,7 +313,7 @@ fn module_resolution_explicit_path_mod_rs_2() {
 
 #[test]
 fn module_resolution_explicit_path_mod_rs_with_win_separator() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "module\bar\mod.rs"]
@@ -322,9 +322,6 @@ fn module_resolution_explicit_path_mod_rs_with_win_separator() {
         //- /module/bar/mod.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -338,7 +335,7 @@ fn module_resolution_explicit_path_mod_rs_with_win_separator() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_with_path_attribute() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "models"]
@@ -349,9 +346,6 @@ fn module_resolution_decl_inside_inline_module_with_path_attribute() {
         //- /models/bar.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -368,7 +362,7 @@ fn module_resolution_decl_inside_inline_module_with_path_attribute() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo {
@@ -378,9 +372,6 @@ fn module_resolution_decl_inside_inline_module() {
         //- /foo/bar.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -397,7 +388,7 @@ fn module_resolution_decl_inside_inline_module() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_2_with_path_attribute() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "models/db"]
@@ -408,9 +399,6 @@ fn module_resolution_decl_inside_inline_module_2_with_path_attribute() {
         //- /models/db/bar.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -427,7 +415,7 @@ fn module_resolution_decl_inside_inline_module_2_with_path_attribute() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_3() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "models/db"]
@@ -439,9 +427,6 @@ fn module_resolution_decl_inside_inline_module_3() {
         //- /models/db/users.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -458,7 +443,7 @@ fn module_resolution_decl_inside_inline_module_3() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_empty_path() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = ""]
@@ -467,12 +452,9 @@ fn module_resolution_decl_inside_inline_module_empty_path() {
             mod bar;
         }
 
-        //- /foo/users.rs
+        //- /users.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -489,32 +471,25 @@ fn module_resolution_decl_inside_inline_module_empty_path() {
 
 #[test]
 fn module_resolution_decl_empty_path() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
-        #[path = ""]
+        #[path = ""] // Should try to read `/` (a directory)
         mod foo;
 
         //- /foo.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
         ⋮crate
-        ⋮foo: t
-        ⋮
-        ⋮crate::foo
-        ⋮Baz: t v
     "###);
 }
 
 #[test]
 fn module_resolution_decl_inside_inline_module_relative_path() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path = "./models"]
@@ -525,9 +500,6 @@ fn module_resolution_decl_inside_inline_module_relative_path() {
         //- /models/bar.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -544,7 +516,7 @@ fn module_resolution_decl_inside_inline_module_relative_path() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_in_crate_root() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo {
@@ -556,9 +528,6 @@ fn module_resolution_decl_inside_inline_module_in_crate_root() {
         //- /foo/baz.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -576,7 +545,7 @@ fn module_resolution_decl_inside_inline_module_in_crate_root() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_in_mod_rs() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -591,9 +560,6 @@ fn module_resolution_decl_inside_inline_module_in_mod_rs() {
         //- /foo/bar/qwe.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -614,7 +580,7 @@ fn module_resolution_decl_inside_inline_module_in_mod_rs() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_in_non_crate_root() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -626,12 +592,9 @@ fn module_resolution_decl_inside_inline_module_in_non_crate_root() {
         }
         use self::bar::baz::Baz;
 
-        //- /bar/qwe.rs
+        //- /foo/bar/qwe.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -652,7 +615,7 @@ fn module_resolution_decl_inside_inline_module_in_non_crate_root() {
 
 #[test]
 fn module_resolution_decl_inside_inline_module_in_non_crate_root_2() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         mod foo;
@@ -667,9 +630,6 @@ fn module_resolution_decl_inside_inline_module_in_non_crate_root_2() {
         //- /bar/baz.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -709,7 +669,7 @@ fn unresolved_module_diagnostics() {
 
 #[test]
 fn module_resolution_decl_inside_module_in_non_crate_root_2() {
-    let map = def_map_with_crate_graph(
+    let map = def_map(
         r###"
         //- /main.rs
         #[path="module/m2.rs"]
@@ -721,9 +681,6 @@ fn module_resolution_decl_inside_module_in_non_crate_root_2() {
         //- /module/submod.rs
         pub struct Baz;
         "###,
-        crate_graph! {
-            "main": ("/main.rs", []),
-        },
     );
 
     assert_snapshot!(map, @r###"
@@ -737,3 +694,66 @@ fn module_resolution_decl_inside_module_in_non_crate_root_2() {
         ⋮Baz: t v
     "###);
 }
+
+#[test]
+fn nested_out_of_line_module() {
+    let map = def_map(
+        r###"
+        //- /lib.rs
+        mod a {
+            mod b {
+                mod c;
+            }
+        }
+
+        //- /a/b/c.rs
+        struct X;
+        "###,
+    );
+
+    assert_snapshot!(map, @r###"
+    crate
+    a: t
+    
+    crate::a
+    b: t
+    
+    crate::a::b
+    c: t
+    
+    crate::a::b::c
+    X: t v
+    "###);
+}
+
+#[test]
+fn nested_out_of_line_module_with_path() {
+    let map = def_map(
+        r###"
+        //- /lib.rs
+        mod a {
+            #[path = "d/e"]
+            mod b {
+                mod c;
+            }
+        }
+
+        //- /a/d/e/c.rs
+        struct X;
+        "###,
+    );
+
+    assert_snapshot!(map, @r###"
+    crate
+    a: t
+    
+    crate::a
+    b: t
+    
+    crate::a::b
+    c: t
+    
+    crate::a::b::c
+    X: t v
+    "###);
+}
diff --git a/crates/ra_hir/src/resolve.rs b/crates/ra_hir/src/resolve.rs
index 39f8e1d8a..3c797c0c3 100644
--- a/crates/ra_hir/src/resolve.rs
+++ b/crates/ra_hir/src/resolve.rs
@@ -43,8 +43,10 @@ pub(crate) enum Scope {
     ModuleScope(ModuleItemMap),
     /// Brings the generic parameters of an item into scope
     GenericParams(Arc<GenericParams>),
-    /// Brings `Self` into scope
+    /// Brings `Self` in `impl` block into scope
     ImplBlockScope(ImplBlock),
+    /// Brings `Self` in enum, struct and union definitions into scope
+    AdtScope(Adt),
     /// Local bindings
     ExprScope(ExprScope),
 }
@@ -54,6 +56,7 @@ pub enum TypeNs {
     SelfType(ImplBlock),
     GenericParam(u32),
     Adt(Adt),
+    AdtSelfType(Adt),
     EnumVariant(EnumVariant),
     TypeAlias(TypeAlias),
     BuiltinType(BuiltinType),
@@ -151,6 +154,12 @@ impl Resolver {
                         return Some((TypeNs::SelfType(*impl_), idx));
                     }
                 }
+                Scope::AdtScope(adt) => {
+                    if first_name == &SELF_TYPE {
+                        let idx = if path.segments.len() == 1 { None } else { Some(1) };
+                        return Some((TypeNs::AdtSelfType(*adt), idx));
+                    }
+                }
                 Scope::ModuleScope(m) => {
                     let (module_def, idx) = m.crate_def_map.resolve_path(db, m.module_id, path);
                     let res = match module_def.take_types()? {
@@ -200,7 +209,10 @@ impl Resolver {
         let skip_to_mod = path.kind != PathKind::Plain && !path.is_self();
         for scope in self.scopes.iter().rev() {
             match scope {
-                Scope::ExprScope(_) | Scope::GenericParams(_) | Scope::ImplBlockScope(_)
+                Scope::AdtScope(_)
+                | Scope::ExprScope(_)
+                | Scope::GenericParams(_)
+                | Scope::ImplBlockScope(_)
                     if skip_to_mod =>
                 {
                     continue
@@ -233,7 +245,13 @@ impl Resolver {
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
-                Scope::ImplBlockScope(_) => continue,
+                Scope::AdtScope(adt) if n_segments > 1 => {
+                    if first_name == &SELF_TYPE {
+                        let ty = TypeNs::AdtSelfType(*adt);
+                        return Some(ResolveValueResult::Partial(ty, 1));
+                    }
+                }
+                Scope::ImplBlockScope(_) | Scope::AdtScope(_) => continue,
 
                 Scope::ModuleScope(m) => {
                     let (module_def, idx) = m.crate_def_map.resolve_path(db, m.module_id, path);
@@ -389,7 +407,8 @@ pub enum ScopeDef {
     ModuleDef(ModuleDef),
     MacroDef(MacroDef),
     GenericParam(u32),
-    SelfType(ImplBlock),
+    ImplSelfType(ImplBlock),
+    AdtSelfType(Adt),
     LocalBinding(PatId),
     Unknown,
 }
@@ -437,7 +456,10 @@ impl Scope {
                 }
             }
             Scope::ImplBlockScope(i) => {
-                f(SELF_TYPE, ScopeDef::SelfType(*i));
+                f(SELF_TYPE, ScopeDef::ImplSelfType(*i));
+            }
+            Scope::AdtScope(i) => {
+                f(SELF_TYPE, ScopeDef::AdtSelfType(*i));
             }
             Scope::ExprScope(e) => {
                 e.expr_scopes.entries(e.scope_id).iter().for_each(|e| {
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 088335e66..a907d6a9f 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -216,7 +216,7 @@ impl SourceAnalyzer {
         let types = self.resolver.resolve_path_in_type_ns_fully(db, &path).map(|ty| match ty {
             TypeNs::SelfType(it) => PathResolution::SelfType(it),
             TypeNs::GenericParam(it) => PathResolution::GenericParam(it),
-            TypeNs::Adt(it) => PathResolution::Def(it.into()),
+            TypeNs::AdtSelfType(it) | TypeNs::Adt(it) => PathResolution::Def(it.into()),
             TypeNs::EnumVariant(it) => PathResolution::Def(it.into()),
             TypeNs::TypeAlias(it) => PathResolution::Def(it.into()),
             TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index d161735e8..cc9746f6d 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -17,8 +17,8 @@ use std::sync::Arc;
 use std::{fmt, iter, mem};
 
 use crate::{
-    db::HirDatabase, expr::ExprId, type_ref::Mutability, Adt, Crate, DefWithBody, GenericParams,
-    HasGenericParams, Name, Trait, TypeAlias,
+    db::HirDatabase, expr::ExprId, type_ref::Mutability, util::make_mut_slice, Adt, Crate,
+    DefWithBody, GenericParams, HasGenericParams, Name, Trait, TypeAlias,
 };
 use display::{HirDisplay, HirFormatter};
 
@@ -308,12 +308,9 @@ impl Substs {
     }
 
     pub fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
-        // Without an Arc::make_mut_slice, we can't avoid the clone here:
-        let mut v: Vec<_> = self.0.iter().cloned().collect();
-        for t in &mut v {
+        for t in make_mut_slice(&mut self.0) {
             t.walk_mut(f);
         }
-        self.0 = v.into();
     }
 
     pub fn as_single(&self) -> &Ty {
@@ -330,8 +327,7 @@ impl Substs {
                 .params_including_parent()
                 .into_iter()
                 .map(|p| Ty::Param { idx: p.idx, name: p.name.clone() })
-                .collect::<Vec<_>>()
-                .into(),
+                .collect(),
         )
     }
 
@@ -342,8 +338,7 @@ impl Substs {
                 .params_including_parent()
                 .into_iter()
                 .map(|p| Ty::Bound(p.idx))
-                .collect::<Vec<_>>()
-                .into(),
+                .collect(),
         )
     }
 
@@ -541,12 +536,9 @@ impl TypeWalk for FnSig {
     }
 
     fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
-        // Without an Arc::make_mut_slice, we can't avoid the clone here:
-        let mut v: Vec<_> = self.params_and_return.iter().cloned().collect();
-        for t in &mut v {
+        for t in make_mut_slice(&mut self.params_and_return) {
             t.walk_mut(f);
         }
-        self.params_and_return = v.into();
     }
 }
 
@@ -756,11 +748,9 @@ impl TypeWalk for Ty {
                 p_ty.parameters.walk_mut(f);
             }
             Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                let mut v: Vec<_> = predicates.iter().cloned().collect();
-                for p in &mut v {
+                for p in make_mut_slice(predicates) {
                     p.walk_mut(f);
                 }
-                *predicates = v.into();
             }
             Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index ca9aefc42..ebaff998e 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -14,7 +14,6 @@
 //! the `ena` crate, which is extracted from rustc.
 
 use std::borrow::Cow;
-use std::iter::{repeat, repeat_with};
 use std::mem;
 use std::ops::Index;
 use std::sync::Arc;
@@ -27,33 +26,39 @@ use ra_prof::profile;
 use test_utils::tested_by;
 
 use super::{
-    autoderef, lower, method_resolution, op, primitive,
+    lower, primitive,
     traits::{Guidance, Obligation, ProjectionPredicate, Solution},
-    ApplicationTy, CallableDef, InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef,
-    Ty, TypableDef, TypeCtor, TypeWalk,
+    ApplicationTy, InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypableDef,
+    TypeCtor, TypeWalk,
 };
 use crate::{
     adt::VariantDef,
     code_model::TypeAlias,
     db::HirDatabase,
     diagnostics::DiagnosticSink,
-    expr::{
-        self, Array, BinaryOp, BindingAnnotation, Body, Expr, ExprId, Literal, Pat, PatId,
-        RecordFieldPat, Statement, UnaryOp,
-    },
-    generics::{GenericParams, HasGenericParams},
-    lang_item::LangItemTarget,
+    expr::{BindingAnnotation, Body, ExprId, PatId},
     name,
-    nameres::Namespace,
-    path::{known, GenericArg, GenericArgs},
+    path::known,
     resolve::{Resolver, TypeNs},
     ty::infer::diagnostics::InferenceDiagnostic,
     type_ref::{Mutability, TypeRef},
-    Adt, AssocItem, ConstData, DefWithBody, FnData, Function, HasBody, Name, Path, StructField,
+    Adt, AssocItem, ConstData, DefWithBody, FnData, Function, HasBody, Path, StructField,
 };
 
+macro_rules! ty_app {
+    ($ctor:pat, $param:pat) => {
+        crate::ty::Ty::Apply(crate::ty::ApplicationTy { ctor: $ctor, parameters: $param })
+    };
+    ($ctor:pat) => {
+        ty_app!($ctor, _)
+    };
+}
+
 mod unify;
 mod path;
+mod expr;
+mod pat;
+mod coerce;
 
 /// The entry point of type inference.
 pub fn infer_query(db: &impl HirDatabase, def: DefWithBody) -> Arc<InferenceResult> {
@@ -197,15 +202,6 @@ struct InferenceContext<'a, D: HirDatabase> {
     coerce_unsized_map: FxHashMap<(TypeCtor, TypeCtor), usize>,
 }
 
-macro_rules! ty_app {
-    ($ctor:pat, $param:pat) => {
-        Ty::Apply(ApplicationTy { ctor: $ctor, parameters: $param })
-    };
-    ($ctor:pat) => {
-        ty_app!($ctor, _)
-    };
-}
-
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn new(db: &'a D, body: Arc<Body>, resolver: Resolver) -> Self {
         InferenceContext {
@@ -221,45 +217,6 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
     }
 
-    fn init_coerce_unsized_map(
-        db: &'a D,
-        resolver: &Resolver,
-    ) -> FxHashMap<(TypeCtor, TypeCtor), usize> {
-        let krate = resolver.krate().unwrap();
-        let impls = match db.lang_item(krate, "coerce_unsized".into()) {
-            Some(LangItemTarget::Trait(trait_)) => db.impls_for_trait(krate, trait_),
-            _ => return FxHashMap::default(),
-        };
-
-        impls
-            .iter()
-            .filter_map(|impl_block| {
-                // `CoerseUnsized` has one generic parameter for the target type.
-                let trait_ref = impl_block.target_trait_ref(db)?;
-                let cur_from_ty = trait_ref.substs.0.get(0)?;
-                let cur_to_ty = trait_ref.substs.0.get(1)?;
-
-                match (&cur_from_ty, cur_to_ty) {
-                    (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => {
-                        // FIXME: We return the first non-equal bound as the type parameter to coerce to unsized type.
-                        // This works for smart-pointer-like coercion, which covers all impls from std.
-                        st1.iter().zip(st2.iter()).enumerate().find_map(|(i, (ty1, ty2))| {
-                            match (ty1, ty2) {
-                                (Ty::Param { idx: p1, .. }, Ty::Param { idx: p2, .. })
-                                    if p1 != p2 =>
-                                {
-                                    Some(((*ctor1, *ctor2), i))
-                                }
-                                _ => None,
-                            }
-                        })
-                    }
-                    _ => None,
-                }
-            })
-            .collect()
-    }
-
     fn resolve_all(mut self) -> InferenceResult {
         // FIXME resolve obligations as well (use Guidance if necessary)
         let mut result = mem::replace(&mut self.result, InferenceResult::default());
@@ -457,7 +414,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     // recursive type
                     return tv.fallback_value();
                 }
-                if let Some(known_ty) = self.var_unification_table.probe_value(inner).known() {
+                if let Some(known_ty) =
+                    self.var_unification_table.inlined_probe_value(inner).known()
+                {
                     // known_ty may contain other variables that are known by now
                     tv_stack.push(inner);
                     let result = self.resolve_ty_as_possible(tv_stack, known_ty.clone());
@@ -485,7 +444,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             match &*ty {
                 Ty::Infer(tv) => {
                     let inner = tv.to_inner();
-                    match self.var_unification_table.probe_value(inner).known() {
+                    match self.var_unification_table.inlined_probe_value(inner).known() {
                         Some(known_ty) => {
                             // The known_ty can't be a type var itself
                             ty = Cow::Owned(known_ty.clone());
@@ -533,7 +492,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     // recursive type
                     return tv.fallback_value();
                 }
-                if let Some(known_ty) = self.var_unification_table.probe_value(inner).known() {
+                if let Some(known_ty) =
+                    self.var_unification_table.inlined_probe_value(inner).known()
+                {
                     // known_ty may contain other variables that are known by now
                     tv_stack.push(inner);
                     let result = self.resolve_ty_completely(tv_stack, known_ty.clone());
@@ -559,6 +520,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
                 Some(TypeNs::Adt(Adt::Struct(it))) => it.into(),
                 Some(TypeNs::Adt(Adt::Union(it))) => it.into(),
+                Some(TypeNs::AdtSelfType(adt)) => adt.into(),
                 Some(TypeNs::EnumVariant(it)) => it.into(),
                 Some(TypeNs::TypeAlias(it)) => it.into(),
 
@@ -594,1080 +556,6 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
     }
 
-    fn infer_tuple_struct_pat(
-        &mut self,
-        path: Option<&Path>,
-        subpats: &[PatId],
-        expected: &Ty,
-        default_bm: BindingMode,
-    ) -> Ty {
-        let (ty, def) = self.resolve_variant(path);
-
-        self.unify(&ty, expected);
-
-        let substs = ty.substs().unwrap_or_else(Substs::empty);
-
-        for (i, &subpat) in subpats.iter().enumerate() {
-            let expected_ty = def
-                .and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
-                .map_or(Ty::Unknown, |field| field.ty(self.db))
-                .subst(&substs);
-            let expected_ty = self.normalize_associated_types_in(expected_ty);
-            self.infer_pat(subpat, &expected_ty, default_bm);
-        }
-
-        ty
-    }
-
-    fn infer_record_pat(
-        &mut self,
-        path: Option<&Path>,
-        subpats: &[RecordFieldPat],
-        expected: &Ty,
-        default_bm: BindingMode,
-        id: PatId,
-    ) -> Ty {
-        let (ty, def) = self.resolve_variant(path);
-        if let Some(variant) = def {
-            self.write_variant_resolution(id.into(), variant);
-        }
-
-        self.unify(&ty, expected);
-
-        let substs = ty.substs().unwrap_or_else(Substs::empty);
-
-        for subpat in subpats {
-            let matching_field = def.and_then(|it| it.field(self.db, &subpat.name));
-            let expected_ty =
-                matching_field.map_or(Ty::Unknown, |field| field.ty(self.db)).subst(&substs);
-            let expected_ty = self.normalize_associated_types_in(expected_ty);
-            self.infer_pat(subpat.pat, &expected_ty, default_bm);
-        }
-
-        ty
-    }
-
-    fn infer_pat(&mut self, pat: PatId, mut expected: &Ty, mut default_bm: BindingMode) -> Ty {
-        let body = Arc::clone(&self.body); // avoid borrow checker problem
-
-        let is_non_ref_pat = match &body[pat] {
-            Pat::Tuple(..)
-            | 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 {
-            while let Some((inner, mutability)) = expected.as_reference() {
-                expected = inner;
-                default_bm = match default_bm {
-                    BindingMode::Move => BindingMode::Ref(mutability),
-                    BindingMode::Ref(Mutability::Shared) => BindingMode::Ref(Mutability::Shared),
-                    BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability),
-                }
-            }
-        } else if let Pat::Ref { .. } = &body[pat] {
-            tested_by!(match_ergonomics_ref);
-            // When you encounter a `&pat` pattern, reset to Move.
-            // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
-            default_bm = BindingMode::Move;
-        }
-
-        // Lose mutability.
-        let default_bm = default_bm;
-        let expected = expected;
-
-        let ty = match &body[pat] {
-            Pat::Tuple(ref args) => {
-                let expectations = match expected.as_tuple() {
-                    Some(parameters) => &*parameters.0,
-                    _ => &[],
-                };
-                let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
-
-                let inner_tys = args
-                    .iter()
-                    .zip(expectations_iter)
-                    .map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm))
-                    .collect();
-
-                Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
-            }
-            Pat::Ref { pat, mutability } => {
-                let expectation = match expected.as_reference() {
-                    Some((inner_ty, exp_mut)) => {
-                        if *mutability != exp_mut {
-                            // FIXME: emit type error?
-                        }
-                        inner_ty
-                    }
-                    _ => &Ty::Unknown,
-                };
-                let subty = self.infer_pat(*pat, expectation, default_bm);
-                Ty::apply_one(TypeCtor::Ref(*mutability), subty)
-            }
-            Pat::TupleStruct { path: p, args: subpats } => {
-                self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm)
-            }
-            Pat::Record { path: p, args: fields } => {
-                self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat)
-            }
-            Pat::Path(path) => {
-                // FIXME use correct resolver for the surrounding expression
-                let resolver = self.resolver.clone();
-                self.infer_path(&resolver, &path, pat.into()).unwrap_or(Ty::Unknown)
-            }
-            Pat::Bind { mode, name: _, subpat } => {
-                let mode = if mode == &BindingAnnotation::Unannotated {
-                    default_bm
-                } else {
-                    BindingMode::convert(*mode)
-                };
-                let inner_ty = if let Some(subpat) = subpat {
-                    self.infer_pat(*subpat, expected, default_bm)
-                } else {
-                    expected.clone()
-                };
-                let inner_ty = self.insert_type_vars_shallow(inner_ty);
-
-                let bound_ty = match mode {
-                    BindingMode::Ref(mutability) => {
-                        Ty::apply_one(TypeCtor::Ref(mutability), inner_ty.clone())
-                    }
-                    BindingMode::Move => inner_ty.clone(),
-                };
-                let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
-                self.write_pat_ty(pat, bound_ty);
-                return inner_ty;
-            }
-            _ => Ty::Unknown,
-        };
-        // use a new type variable if we got Ty::Unknown here
-        let ty = self.insert_type_vars_shallow(ty);
-        self.unify(&ty, expected);
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
-        self.write_pat_ty(pat, ty.clone());
-        ty
-    }
-
-    fn substs_for_method_call(
-        &mut self,
-        def_generics: Option<Arc<GenericParams>>,
-        generic_args: Option<&GenericArgs>,
-        receiver_ty: &Ty,
-    ) -> Substs {
-        let (parent_param_count, param_count) =
-            def_generics.as_ref().map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
-        let mut substs = Vec::with_capacity(parent_param_count + param_count);
-        // Parent arguments are unknown, except for the receiver type
-        if let Some(parent_generics) = def_generics.and_then(|p| p.parent_params.clone()) {
-            for param in &parent_generics.params {
-                if param.name == name::SELF_TYPE {
-                    substs.push(receiver_ty.clone());
-                } else {
-                    substs.push(Ty::Unknown);
-                }
-            }
-        }
-        // handle provided type arguments
-        if let Some(generic_args) = generic_args {
-            // if args are provided, it should be all of them, but we can't rely on that
-            for arg in generic_args.args.iter().take(param_count) {
-                match arg {
-                    GenericArg::Type(type_ref) => {
-                        let ty = self.make_ty(type_ref);
-                        substs.push(ty);
-                    }
-                }
-            }
-        };
-        let supplied_params = substs.len();
-        for _ in supplied_params..parent_param_count + param_count {
-            substs.push(Ty::Unknown);
-        }
-        assert_eq!(substs.len(), parent_param_count + param_count);
-        Substs(substs.into())
-    }
-
-    fn register_obligations_for_call(&mut self, callable_ty: &Ty) {
-        if let Ty::Apply(a_ty) = callable_ty {
-            if let TypeCtor::FnDef(def) = a_ty.ctor {
-                let generic_predicates = self.db.generic_predicates(def.into());
-                for predicate in generic_predicates.iter() {
-                    let predicate = predicate.clone().subst(&a_ty.parameters);
-                    if let Some(obligation) = Obligation::from_predicate(predicate) {
-                        self.obligations.push(obligation);
-                    }
-                }
-                // add obligation for trait implementation, if this is a trait method
-                match def {
-                    CallableDef::Function(f) => {
-                        if let Some(trait_) = f.parent_trait(self.db) {
-                            // construct a TraitDef
-                            let substs = a_ty.parameters.prefix(
-                                trait_.generic_params(self.db).count_params_including_parent(),
-                            );
-                            self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
-                        }
-                    }
-                    CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
-                }
-            }
-        }
-    }
-
-    fn infer_method_call(
-        &mut self,
-        tgt_expr: ExprId,
-        receiver: ExprId,
-        args: &[ExprId],
-        method_name: &Name,
-        generic_args: Option<&GenericArgs>,
-    ) -> Ty {
-        let receiver_ty = self.infer_expr(receiver, &Expectation::none());
-        let canonicalized_receiver = self.canonicalizer().canonicalize_ty(receiver_ty.clone());
-        let resolved = method_resolution::lookup_method(
-            &canonicalized_receiver.value,
-            self.db,
-            method_name,
-            &self.resolver,
-        );
-        let (derefed_receiver_ty, method_ty, def_generics) = match resolved {
-            Some((ty, func)) => {
-                let ty = canonicalized_receiver.decanonicalize_ty(ty);
-                self.write_method_resolution(tgt_expr, func);
-                (
-                    ty,
-                    self.db.type_for_def(func.into(), Namespace::Values),
-                    Some(func.generic_params(self.db)),
-                )
-            }
-            None => (receiver_ty, Ty::Unknown, None),
-        };
-        let substs = self.substs_for_method_call(def_generics, generic_args, &derefed_receiver_ty);
-        let method_ty = method_ty.apply_substs(substs);
-        let method_ty = self.insert_type_vars(method_ty);
-        self.register_obligations_for_call(&method_ty);
-        let (expected_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) {
-            Some(sig) => {
-                if !sig.params().is_empty() {
-                    (sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone())
-                } else {
-                    (Ty::Unknown, Vec::new(), sig.ret().clone())
-                }
-            }
-            None => (Ty::Unknown, Vec::new(), Ty::Unknown),
-        };
-        // Apply autoref so the below unification works correctly
-        // FIXME: return correct autorefs from lookup_method
-        let actual_receiver_ty = match expected_receiver_ty.as_reference() {
-            Some((_, mutability)) => Ty::apply_one(TypeCtor::Ref(mutability), derefed_receiver_ty),
-            _ => derefed_receiver_ty,
-        };
-        self.unify(&expected_receiver_ty, &actual_receiver_ty);
-
-        self.check_call_arguments(args, &param_tys);
-        let ret_ty = self.normalize_associated_types_in(ret_ty);
-        ret_ty
-    }
-
-    /// Infer type of expression with possibly implicit coerce to the expected type.
-    /// Return the type after possible coercion.
-    fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
-        let ty = self.infer_expr_inner(expr, &expected);
-        let ty = if !self.coerce(&ty, &expected.ty) {
-            self.result
-                .type_mismatches
-                .insert(expr, TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() });
-            // Return actual type when type mismatch.
-            // This is needed for diagnostic when return type mismatch.
-            ty
-        } else if expected.ty == Ty::Unknown {
-            ty
-        } else {
-            expected.ty.clone()
-        };
-
-        self.resolve_ty_as_possible(&mut vec![], ty)
-    }
-
-    /// Merge two types from different branches, with possible implicit coerce.
-    ///
-    /// Note that it is only possible that one type are coerced to another.
-    /// Coercing both types to another least upper bound type is not possible in rustc,
-    /// which will simply result in "incompatible types" error.
-    fn coerce_merge_branch<'t>(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
-        if self.coerce(ty1, ty2) {
-            ty2.clone()
-        } else if self.coerce(ty2, ty1) {
-            ty1.clone()
-        } else {
-            tested_by!(coerce_merge_fail_fallback);
-            // For incompatible types, we use the latter one as result
-            // to be better recovery for `if` without `else`.
-            ty2.clone()
-        }
-    }
-
-    /// Unify two types, but may coerce the first one to the second one
-    /// using "implicit coercion rules" if needed.
-    ///
-    /// See: https://doc.rust-lang.org/nomicon/coercions.html
-    fn coerce(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
-        let from_ty = self.resolve_ty_shallow(from_ty).into_owned();
-        let to_ty = self.resolve_ty_shallow(to_ty);
-        self.coerce_inner(from_ty, &to_ty)
-    }
-
-    fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool {
-        match (&from_ty, to_ty) {
-            // Never type will make type variable to fallback to Never Type instead of Unknown.
-            (ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => {
-                let var = self.new_maybe_never_type_var();
-                self.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
-                return true;
-            }
-            (ty_app!(TypeCtor::Never), _) => return true,
-
-            // Trivial cases, this should go after `never` check to
-            // avoid infer result type to be never
-            _ => {
-                if self.unify_inner_trivial(&from_ty, &to_ty) {
-                    return true;
-                }
-            }
-        }
-
-        // Pointer weakening and function to pointer
-        match (&mut from_ty, to_ty) {
-            // `*mut T`, `&mut T, `&T`` -> `*const T`
-            // `&mut T` -> `&T`
-            // `&mut T` -> `*mut T`
-            (ty_app!(c1@TypeCtor::RawPtr(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
-            | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
-            | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::Ref(Mutability::Shared)))
-            | (ty_app!(c1@TypeCtor::Ref(Mutability::Mut)), ty_app!(c2@TypeCtor::RawPtr(_))) => {
-                *c1 = *c2;
-            }
-
-            // Illegal mutablity conversion
-            (
-                ty_app!(TypeCtor::RawPtr(Mutability::Shared)),
-                ty_app!(TypeCtor::RawPtr(Mutability::Mut)),
-            )
-            | (
-                ty_app!(TypeCtor::Ref(Mutability::Shared)),
-                ty_app!(TypeCtor::Ref(Mutability::Mut)),
-            ) => return false,
-
-            // `{function_type}` -> `fn()`
-            (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnPtr { .. })) => {
-                match from_ty.callable_sig(self.db) {
-                    None => return false,
-                    Some(sig) => {
-                        let num_args = sig.params_and_return.len() as u16 - 1;
-                        from_ty =
-                            Ty::apply(TypeCtor::FnPtr { num_args }, Substs(sig.params_and_return));
-                    }
-                }
-            }
-
-            _ => {}
-        }
-
-        if let Some(ret) = self.try_coerce_unsized(&from_ty, &to_ty) {
-            return ret;
-        }
-
-        // Auto Deref if cannot coerce
-        match (&from_ty, to_ty) {
-            // FIXME: DerefMut
-            (ty_app!(TypeCtor::Ref(_), st1), ty_app!(TypeCtor::Ref(_), st2)) => {
-                self.unify_autoderef_behind_ref(&st1[0], &st2[0])
-            }
-
-            // Otherwise, normal unify
-            _ => self.unify(&from_ty, to_ty),
-        }
-    }
-
-    /// Coerce a type using `from_ty: CoerceUnsized<ty_ty>`
-    ///
-    /// See: https://doc.rust-lang.org/nightly/std/marker/trait.CoerceUnsized.html
-    fn try_coerce_unsized(&mut self, from_ty: &Ty, to_ty: &Ty) -> Option<bool> {
-        let (ctor1, st1, ctor2, st2) = match (from_ty, to_ty) {
-            (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => (ctor1, st1, ctor2, st2),
-            _ => return None,
-        };
-
-        let coerce_generic_index = *self.coerce_unsized_map.get(&(*ctor1, *ctor2))?;
-
-        // Check `Unsize` first
-        match self.check_unsize_and_coerce(
-            st1.0.get(coerce_generic_index)?,
-            st2.0.get(coerce_generic_index)?,
-            0,
-        ) {
-            Some(true) => {}
-            ret => return ret,
-        }
-
-        let ret = st1
-            .iter()
-            .zip(st2.iter())
-            .enumerate()
-            .filter(|&(idx, _)| idx != coerce_generic_index)
-            .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
-
-        Some(ret)
-    }
-
-    /// Check if `from_ty: Unsize<to_ty>`, and coerce to `to_ty` if it holds.
-    ///
-    /// It should not be directly called. It is only used by `try_coerce_unsized`.
-    ///
-    /// See: https://doc.rust-lang.org/nightly/std/marker/trait.Unsize.html
-    fn check_unsize_and_coerce(&mut self, from_ty: &Ty, to_ty: &Ty, depth: usize) -> Option<bool> {
-        if depth > 1000 {
-            panic!("Infinite recursion in coercion");
-        }
-
-        match (&from_ty, &to_ty) {
-            // `[T; N]` -> `[T]`
-            (ty_app!(TypeCtor::Array, st1), ty_app!(TypeCtor::Slice, st2)) => {
-                Some(self.unify(&st1[0], &st2[0]))
-            }
-
-            // `T` -> `dyn Trait` when `T: Trait`
-            (_, Ty::Dyn(_)) => {
-                // FIXME: Check predicates
-                Some(true)
-            }
-
-            // `(..., T)` -> `(..., U)` when `T: Unsize<U>`
-            (
-                ty_app!(TypeCtor::Tuple { cardinality: len1 }, st1),
-                ty_app!(TypeCtor::Tuple { cardinality: len2 }, st2),
-            ) => {
-                if len1 != len2 || *len1 == 0 {
-                    return None;
-                }
-
-                match self.check_unsize_and_coerce(
-                    st1.last().unwrap(),
-                    st2.last().unwrap(),
-                    depth + 1,
-                ) {
-                    Some(true) => {}
-                    ret => return ret,
-                }
-
-                let ret = st1[..st1.len() - 1]
-                    .iter()
-                    .zip(&st2[..st2.len() - 1])
-                    .all(|(ty1, ty2)| self.unify(ty1, ty2));
-
-                Some(ret)
-            }
-
-            // Foo<..., T, ...> is Unsize<Foo<..., U, ...>> if:
-            // - T: Unsize<U>
-            // - Foo is a struct
-            // - Only the last field of Foo has a type involving T
-            // - T is not part of the type of any other fields
-            // - Bar<T>: Unsize<Bar<U>>, if the last field of Foo has type Bar<T>
-            (
-                ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
-                ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
-            ) if struct1 == struct2 => {
-                let fields = struct1.fields(self.db);
-                let (last_field, prev_fields) = fields.split_last()?;
-
-                // Get the generic parameter involved in the last field.
-                let unsize_generic_index = {
-                    let mut index = None;
-                    let mut multiple_param = false;
-                    last_field.ty(self.db).walk(&mut |ty| match ty {
-                        &Ty::Param { idx, .. } => {
-                            if index.is_none() {
-                                index = Some(idx);
-                            } else if Some(idx) != index {
-                                multiple_param = true;
-                            }
-                        }
-                        _ => {}
-                    });
-
-                    if multiple_param {
-                        return None;
-                    }
-                    index?
-                };
-
-                // Check other fields do not involve it.
-                let mut multiple_used = false;
-                prev_fields.iter().for_each(|field| {
-                    field.ty(self.db).walk(&mut |ty| match ty {
-                        &Ty::Param { idx, .. } if idx == unsize_generic_index => {
-                            multiple_used = true
-                        }
-                        _ => {}
-                    })
-                });
-                if multiple_used {
-                    return None;
-                }
-
-                let unsize_generic_index = unsize_generic_index as usize;
-
-                // Check `Unsize` first
-                match self.check_unsize_and_coerce(
-                    st1.get(unsize_generic_index)?,
-                    st2.get(unsize_generic_index)?,
-                    depth + 1,
-                ) {
-                    Some(true) => {}
-                    ret => return ret,
-                }
-
-                // Then unify other parameters
-                let ret = st1
-                    .iter()
-                    .zip(st2.iter())
-                    .enumerate()
-                    .filter(|&(idx, _)| idx != unsize_generic_index)
-                    .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
-
-                Some(ret)
-            }
-
-            _ => None,
-        }
-    }
-
-    /// Unify `from_ty` to `to_ty` with optional auto Deref
-    ///
-    /// Note that the parameters are already stripped the outer reference.
-    fn unify_autoderef_behind_ref(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
-        let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
-        let to_ty = self.resolve_ty_shallow(&to_ty);
-        // FIXME: Auto DerefMut
-        for derefed_ty in
-            autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
-        {
-            let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
-            match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
-                // Stop when constructor matches.
-                (ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => {
-                    // It will not recurse to `coerce`.
-                    return self.unify_substs(st1, st2, 0);
-                }
-                _ => {}
-            }
-        }
-
-        false
-    }
-
-    fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
-        let ty = self.infer_expr_inner(tgt_expr, expected);
-        let could_unify = self.unify(&ty, &expected.ty);
-        if !could_unify {
-            self.result.type_mismatches.insert(
-                tgt_expr,
-                TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
-            );
-        }
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
-        ty
-    }
-
-    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] {
-            Expr::Missing => Ty::Unknown,
-            Expr::If { condition, then_branch, else_branch } => {
-                // if let is desugared to match, so this is always simple if
-                self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
-
-                let then_ty = self.infer_expr_inner(*then_branch, &expected);
-                let else_ty = match else_branch {
-                    Some(else_branch) => self.infer_expr_inner(*else_branch, &expected),
-                    None => Ty::unit(),
-                };
-
-                self.coerce_merge_branch(&then_ty, &else_ty)
-            }
-            Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
-            Expr::TryBlock { body } => {
-                let _inner = self.infer_expr(*body, expected);
-                // FIXME should be std::result::Result<{inner}, _>
-                Ty::Unknown
-            }
-            Expr::Loop { body } => {
-                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
-                // FIXME handle break with value
-                Ty::simple(TypeCtor::Never)
-            }
-            Expr::While { condition, body } => {
-                // while let is desugared to a match loop, so this is always simple while
-                self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
-                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
-                Ty::unit()
-            }
-            Expr::For { iterable, body, pat } => {
-                let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
-
-                let pat_ty = match self.resolve_into_iter_item() {
-                    Some(into_iter_item_alias) => {
-                        let pat_ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: pat_ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: into_iter_item_alias,
-                                parameters: Substs::single(iterable_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], pat_ty)
-                    }
-                    None => Ty::Unknown,
-                };
-
-                self.infer_pat(*pat, &pat_ty, BindingMode::default());
-                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
-                Ty::unit()
-            }
-            Expr::Lambda { body, args, arg_types } => {
-                assert_eq!(args.len(), arg_types.len());
-
-                let mut sig_tys = Vec::new();
-
-                for (arg_pat, arg_type) in args.iter().zip(arg_types.iter()) {
-                    let expected = if let Some(type_ref) = arg_type {
-                        self.make_ty(type_ref)
-                    } else {
-                        Ty::Unknown
-                    };
-                    let arg_ty = self.infer_pat(*arg_pat, &expected, BindingMode::default());
-                    sig_tys.push(arg_ty);
-                }
-
-                // add return type
-                let ret_ty = self.new_type_var();
-                sig_tys.push(ret_ty.clone());
-                let sig_ty = Ty::apply(
-                    TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
-                    Substs(sig_tys.into()),
-                );
-                let closure_ty = Ty::apply_one(
-                    TypeCtor::Closure { def: self.body.owner(), expr: tgt_expr },
-                    sig_ty,
-                );
-
-                // Eagerly try to relate the closure type with the expected
-                // type, otherwise we often won't have enough information to
-                // infer the body.
-                self.coerce(&closure_ty, &expected.ty);
-
-                self.infer_expr(*body, &Expectation::has_type(ret_ty));
-                closure_ty
-            }
-            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)
-                    }
-                };
-                self.register_obligations_for_call(&callee_ty);
-                self.check_call_arguments(args, &param_tys);
-                let ret_ty = self.normalize_associated_types_in(ret_ty);
-                ret_ty
-            }
-            Expr::MethodCall { receiver, args, method_name, generic_args } => self
-                .infer_method_call(tgt_expr, *receiver, &args, &method_name, generic_args.as_ref()),
-            Expr::Match { expr, arms } => {
-                let input_ty = self.infer_expr(*expr, &Expectation::none());
-
-                let mut result_ty = self.new_maybe_never_type_var();
-
-                for arm in arms {
-                    for &pat in &arm.pats {
-                        let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default());
-                    }
-                    if let Some(guard_expr) = arm.guard {
-                        self.infer_expr(
-                            guard_expr,
-                            &Expectation::has_type(Ty::simple(TypeCtor::Bool)),
-                        );
-                    }
-
-                    let arm_ty = self.infer_expr_inner(arm.expr, &expected);
-                    result_ty = self.coerce_merge_branch(&result_ty, &arm_ty);
-                }
-
-                result_ty
-            }
-            Expr::Path(p) => {
-                // FIXME this could be more efficient...
-                let resolver = expr::resolver_for_expr(self.body.clone(), self.db, tgt_expr);
-                self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or(Ty::Unknown)
-            }
-            Expr::Continue => Ty::simple(TypeCtor::Never),
-            Expr::Break { expr } => {
-                if let Some(expr) = expr {
-                    // FIXME handle break with value
-                    self.infer_expr(*expr, &Expectation::none());
-                }
-                Ty::simple(TypeCtor::Never)
-            }
-            Expr::Return { expr } => {
-                if let Some(expr) = expr {
-                    self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
-                }
-                Ty::simple(TypeCtor::Never)
-            }
-            Expr::RecordLit { path, fields, spread } => {
-                let (ty, def_id) = self.resolve_variant(path.as_ref());
-                if let Some(variant) = def_id {
-                    self.write_variant_resolution(tgt_expr.into(), variant);
-                }
-
-                self.unify(&ty, &expected.ty);
-
-                let substs = ty.substs().unwrap_or_else(Substs::empty);
-                for (field_idx, field) in fields.iter().enumerate() {
-                    let field_ty = def_id
-                        .and_then(|it| match it.field(self.db, &field.name) {
-                            Some(field) => Some(field),
-                            None => {
-                                self.push_diagnostic(InferenceDiagnostic::NoSuchField {
-                                    expr: tgt_expr,
-                                    field: field_idx,
-                                });
-                                None
-                            }
-                        })
-                        .map_or(Ty::Unknown, |field| field.ty(self.db))
-                        .subst(&substs);
-                    self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
-                }
-                if let Some(expr) = spread {
-                    self.infer_expr(*expr, &Expectation::has_type(ty.clone()));
-                }
-                ty
-            }
-            Expr::Field { expr, name } => {
-                let receiver_ty = self.infer_expr(*expr, &Expectation::none());
-                let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
-                let ty = autoderef::autoderef(
-                    self.db,
-                    &self.resolver.clone(),
-                    canonicalized.value.clone(),
-                )
-                .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
-                    Ty::Apply(a_ty) => match a_ty.ctor {
-                        TypeCtor::Tuple { .. } => name
-                            .as_tuple_index()
-                            .and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
-                        TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
-                            self.write_field_resolution(tgt_expr, field);
-                            field.ty(self.db).subst(&a_ty.parameters)
-                        }),
-                        _ => None,
-                    },
-                    _ => None,
-                })
-                .unwrap_or(Ty::Unknown);
-                let ty = self.insert_type_vars(ty);
-                self.normalize_associated_types_in(ty)
-            }
-            Expr::Await { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                let ty = match self.resolve_future_future_output() {
-                    Some(future_future_output_alias) => {
-                        let ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: future_future_output_alias,
-                                parameters: Substs::single(inner_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], ty)
-                    }
-                    None => Ty::Unknown,
-                };
-                ty
-            }
-            Expr::Try { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                let ty = match self.resolve_ops_try_ok() {
-                    Some(ops_try_ok_alias) => {
-                        let ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: ops_try_ok_alias,
-                                parameters: Substs::single(inner_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], ty)
-                    }
-                    None => Ty::Unknown,
-                };
-                ty
-            }
-            Expr::Cast { expr, type_ref } => {
-                let _inner_ty = self.infer_expr(*expr, &Expectation::none());
-                let cast_ty = self.make_ty(type_ref);
-                // FIXME check the cast...
-                cast_ty
-            }
-            Expr::Ref { expr, mutability } => {
-                let expectation =
-                    if let Some((exp_inner, exp_mutability)) = &expected.ty.as_reference() {
-                        if *exp_mutability == Mutability::Mut && *mutability == Mutability::Shared {
-                            // FIXME: throw type error - expected mut reference but found shared ref,
-                            // which cannot be coerced
-                        }
-                        Expectation::has_type(Ty::clone(exp_inner))
-                    } else {
-                        Expectation::none()
-                    };
-                // FIXME reference coercions etc.
-                let inner_ty = self.infer_expr(*expr, &expectation);
-                Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
-            }
-            Expr::Box { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                if let Some(box_) = self.resolve_boxed_box() {
-                    Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
-                } else {
-                    Ty::Unknown
-                }
-            }
-            Expr::UnaryOp { expr, op } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                match op {
-                    UnaryOp::Deref => {
-                        let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
-                        if let Some(derefed_ty) =
-                            autoderef::deref(self.db, &self.resolver, &canonicalized.value)
-                        {
-                            canonicalized.decanonicalize_ty(derefed_ty.value)
-                        } else {
-                            Ty::Unknown
-                        }
-                    }
-                    UnaryOp::Neg => {
-                        match &inner_ty {
-                            Ty::Apply(a_ty) => match a_ty.ctor {
-                                TypeCtor::Int(primitive::UncertainIntTy::Unknown)
-                                | TypeCtor::Int(primitive::UncertainIntTy::Known(
-                                    primitive::IntTy {
-                                        signedness: primitive::Signedness::Signed,
-                                        ..
-                                    },
-                                ))
-                                | TypeCtor::Float(..) => inner_ty,
-                                _ => Ty::Unknown,
-                            },
-                            Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => {
-                                inner_ty
-                            }
-                            // FIXME: resolve ops::Neg trait
-                            _ => Ty::Unknown,
-                        }
-                    }
-                    UnaryOp::Not => {
-                        match &inner_ty {
-                            Ty::Apply(a_ty) => match a_ty.ctor {
-                                TypeCtor::Bool | TypeCtor::Int(_) => inner_ty,
-                                _ => Ty::Unknown,
-                            },
-                            Ty::Infer(InferTy::IntVar(..)) => inner_ty,
-                            // FIXME: resolve ops::Not trait for inner_ty
-                            _ => Ty::Unknown,
-                        }
-                    }
-                }
-            }
-            Expr::BinaryOp { lhs, rhs, op } => match op {
-                Some(op) => {
-                    let lhs_expectation = match op {
-                        BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)),
-                        _ => Expectation::none(),
-                    };
-                    let lhs_ty = self.infer_expr(*lhs, &lhs_expectation);
-                    // FIXME: find implementation of trait corresponding to operation
-                    // symbol and resolve associated `Output` type
-                    let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty);
-                    let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation));
-
-                    // FIXME: similar as above, return ty is often associated trait type
-                    op::binary_op_return_ty(*op, rhs_ty)
-                }
-                _ => Ty::Unknown,
-            },
-            Expr::Index { base, index } => {
-                let _base_ty = self.infer_expr(*base, &Expectation::none());
-                let _index_ty = self.infer_expr(*index, &Expectation::none());
-                // FIXME: use `std::ops::Index::Output` to figure out the real return type
-                Ty::Unknown
-            }
-            Expr::Tuple { exprs } => {
-                let mut tys = match &expected.ty {
-                    ty_app!(TypeCtor::Tuple { .. }, st) => st
-                        .iter()
-                        .cloned()
-                        .chain(repeat_with(|| self.new_type_var()))
-                        .take(exprs.len())
-                        .collect::<Vec<_>>(),
-                    _ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
-                };
-
-                for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
-                    self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone()));
-                }
-
-                Ty::apply(TypeCtor::Tuple { cardinality: tys.len() as u16 }, Substs(tys.into()))
-            }
-            Expr::Array(array) => {
-                let elem_ty = match &expected.ty {
-                    ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
-                        st.as_single().clone()
-                    }
-                    _ => self.new_type_var(),
-                };
-
-                match array {
-                    Array::ElementList(items) => {
-                        for expr in items.iter() {
-                            self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
-                        }
-                    }
-                    Array::Repeat { initializer, repeat } => {
-                        self.infer_expr_coerce(
-                            *initializer,
-                            &Expectation::has_type(elem_ty.clone()),
-                        );
-                        self.infer_expr(
-                            *repeat,
-                            &Expectation::has_type(Ty::simple(TypeCtor::Int(
-                                primitive::UncertainIntTy::Known(primitive::IntTy::usize()),
-                            ))),
-                        );
-                    }
-                }
-
-                Ty::apply_one(TypeCtor::Array, elem_ty)
-            }
-            Expr::Literal(lit) => match lit {
-                Literal::Bool(..) => Ty::simple(TypeCtor::Bool),
-                Literal::String(..) => {
-                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
-                }
-                Literal::ByteString(..) => {
-                    let byte_type = Ty::simple(TypeCtor::Int(primitive::UncertainIntTy::Known(
-                        primitive::IntTy::u8(),
-                    )));
-                    let slice_type = Ty::apply_one(TypeCtor::Slice, byte_type);
-                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), slice_type)
-                }
-                Literal::Char(..) => Ty::simple(TypeCtor::Char),
-                Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int(*ty)),
-                Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float(*ty)),
-            },
-        };
-        // use a new type variable if we got Ty::Unknown here
-        let ty = self.insert_type_vars_shallow(ty);
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
-        self.write_expr_ty(tgt_expr, ty.clone());
-        ty
-    }
-
-    fn infer_block(
-        &mut self,
-        statements: &[Statement],
-        tail: Option<ExprId>,
-        expected: &Expectation,
-    ) -> Ty {
-        let mut diverges = false;
-        for stmt in statements {
-            match stmt {
-                Statement::Let { pat, type_ref, initializer } => {
-                    let decl_ty =
-                        type_ref.as_ref().map(|tr| self.make_ty(tr)).unwrap_or(Ty::Unknown);
-
-                    // Always use the declared type when specified
-                    let mut ty = decl_ty.clone();
-
-                    if let Some(expr) = initializer {
-                        let actual_ty =
-                            self.infer_expr_coerce(*expr, &Expectation::has_type(decl_ty.clone()));
-                        if decl_ty == Ty::Unknown {
-                            ty = actual_ty;
-                        }
-                    }
-
-                    let ty = self.resolve_ty_as_possible(&mut vec![], ty);
-                    self.infer_pat(*pat, &ty, BindingMode::default());
-                }
-                Statement::Expr(expr) => {
-                    if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
-                        diverges = true;
-                    }
-                }
-            }
-        }
-
-        let ty = if let Some(expr) = tail {
-            self.infer_expr_coerce(expr, expected)
-        } else {
-            self.coerce(&Ty::unit(), &expected.ty);
-            Ty::unit()
-        };
-        if diverges {
-            Ty::simple(TypeCtor::Never)
-        } else {
-            ty
-        }
-    }
-
-    fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) {
-        // Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 --
-        // We do this in a pretty awful way: first we type-check any arguments
-        // that are not closures, then we type-check the closures. This is so
-        // that we have more information about the types of arguments when we
-        // type-check the functions. This isn't really the right way to do this.
-        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,
-                };
-
-                if is_closure != check_closures {
-                    continue;
-                }
-
-                let param_ty = self.normalize_associated_types_in(param_ty);
-                self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
-            }
-        }
-    }
-
     fn collect_const(&mut self, data: &ConstData) {
         self.return_ty = self.make_ty(data.type_ref());
     }
diff --git a/crates/ra_hir/src/ty/infer/coerce.rs b/crates/ra_hir/src/ty/infer/coerce.rs
new file mode 100644
index 000000000..0429a9866
--- /dev/null
+++ b/crates/ra_hir/src/ty/infer/coerce.rs
@@ -0,0 +1,336 @@
+//! Coercion logic. Coercions are certain type conversions that can implicitly
+//! happen in certain places, e.g. weakening `&mut` to `&` or deref coercions
+//! like going from `&Vec<T>` to `&[T]`.
+//!
+//! See: https://doc.rust-lang.org/nomicon/coercions.html
+
+use rustc_hash::FxHashMap;
+
+use test_utils::tested_by;
+
+use super::{InferTy, InferenceContext, TypeVarValue};
+use crate::{
+    db::HirDatabase,
+    lang_item::LangItemTarget,
+    resolve::Resolver,
+    ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
+    type_ref::Mutability,
+    Adt,
+};
+
+impl<'a, D: HirDatabase> InferenceContext<'a, D> {
+    /// Unify two types, but may coerce the first one to the second one
+    /// using "implicit coercion rules" if needed.
+    pub(super) fn coerce(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
+        let from_ty = self.resolve_ty_shallow(from_ty).into_owned();
+        let to_ty = self.resolve_ty_shallow(to_ty);
+        self.coerce_inner(from_ty, &to_ty)
+    }
+
+    /// Merge two types from different branches, with possible implicit coerce.
+    ///
+    /// Note that it is only possible that one type are coerced to another.
+    /// Coercing both types to another least upper bound type is not possible in rustc,
+    /// which will simply result in "incompatible types" error.
+    pub(super) fn coerce_merge_branch<'t>(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
+        if self.coerce(ty1, ty2) {
+            ty2.clone()
+        } else if self.coerce(ty2, ty1) {
+            ty1.clone()
+        } else {
+            tested_by!(coerce_merge_fail_fallback);
+            // For incompatible types, we use the latter one as result
+            // to be better recovery for `if` without `else`.
+            ty2.clone()
+        }
+    }
+
+    pub(super) fn init_coerce_unsized_map(
+        db: &'a D,
+        resolver: &Resolver,
+    ) -> FxHashMap<(TypeCtor, TypeCtor), usize> {
+        let krate = resolver.krate().unwrap();
+        let impls = match db.lang_item(krate, "coerce_unsized".into()) {
+            Some(LangItemTarget::Trait(trait_)) => db.impls_for_trait(krate, trait_),
+            _ => return FxHashMap::default(),
+        };
+
+        impls
+            .iter()
+            .filter_map(|impl_block| {
+                // `CoerseUnsized` has one generic parameter for the target type.
+                let trait_ref = impl_block.target_trait_ref(db)?;
+                let cur_from_ty = trait_ref.substs.0.get(0)?;
+                let cur_to_ty = trait_ref.substs.0.get(1)?;
+
+                match (&cur_from_ty, cur_to_ty) {
+                    (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => {
+                        // FIXME: We return the first non-equal bound as the type parameter to coerce to unsized type.
+                        // This works for smart-pointer-like coercion, which covers all impls from std.
+                        st1.iter().zip(st2.iter()).enumerate().find_map(|(i, (ty1, ty2))| {
+                            match (ty1, ty2) {
+                                (Ty::Param { idx: p1, .. }, Ty::Param { idx: p2, .. })
+                                    if p1 != p2 =>
+                                {
+                                    Some(((*ctor1, *ctor2), i))
+                                }
+                                _ => None,
+                            }
+                        })
+                    }
+                    _ => None,
+                }
+            })
+            .collect()
+    }
+
+    fn coerce_inner(&mut self, mut from_ty: Ty, to_ty: &Ty) -> bool {
+        match (&from_ty, to_ty) {
+            // Never type will make type variable to fallback to Never Type instead of Unknown.
+            (ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => {
+                let var = self.new_maybe_never_type_var();
+                self.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
+                return true;
+            }
+            (ty_app!(TypeCtor::Never), _) => return true,
+
+            // Trivial cases, this should go after `never` check to
+            // avoid infer result type to be never
+            _ => {
+                if self.unify_inner_trivial(&from_ty, &to_ty) {
+                    return true;
+                }
+            }
+        }
+
+        // Pointer weakening and function to pointer
+        match (&mut from_ty, to_ty) {
+            // `*mut T`, `&mut T, `&T`` -> `*const T`
+            // `&mut T` -> `&T`
+            // `&mut T` -> `*mut T`
+            (ty_app!(c1@TypeCtor::RawPtr(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
+            | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::RawPtr(Mutability::Shared)))
+            | (ty_app!(c1@TypeCtor::Ref(_)), ty_app!(c2@TypeCtor::Ref(Mutability::Shared)))
+            | (ty_app!(c1@TypeCtor::Ref(Mutability::Mut)), ty_app!(c2@TypeCtor::RawPtr(_))) => {
+                *c1 = *c2;
+            }
+
+            // Illegal mutablity conversion
+            (
+                ty_app!(TypeCtor::RawPtr(Mutability::Shared)),
+                ty_app!(TypeCtor::RawPtr(Mutability::Mut)),
+            )
+            | (
+                ty_app!(TypeCtor::Ref(Mutability::Shared)),
+                ty_app!(TypeCtor::Ref(Mutability::Mut)),
+            ) => return false,
+
+            // `{function_type}` -> `fn()`
+            (ty_app!(TypeCtor::FnDef(_)), ty_app!(TypeCtor::FnPtr { .. })) => {
+                match from_ty.callable_sig(self.db) {
+                    None => return false,
+                    Some(sig) => {
+                        let num_args = sig.params_and_return.len() as u16 - 1;
+                        from_ty =
+                            Ty::apply(TypeCtor::FnPtr { num_args }, Substs(sig.params_and_return));
+                    }
+                }
+            }
+
+            _ => {}
+        }
+
+        if let Some(ret) = self.try_coerce_unsized(&from_ty, &to_ty) {
+            return ret;
+        }
+
+        // Auto Deref if cannot coerce
+        match (&from_ty, to_ty) {
+            // FIXME: DerefMut
+            (ty_app!(TypeCtor::Ref(_), st1), ty_app!(TypeCtor::Ref(_), st2)) => {
+                self.unify_autoderef_behind_ref(&st1[0], &st2[0])
+            }
+
+            // Otherwise, normal unify
+            _ => self.unify(&from_ty, to_ty),
+        }
+    }
+
+    /// Coerce a type using `from_ty: CoerceUnsized<ty_ty>`
+    ///
+    /// See: https://doc.rust-lang.org/nightly/std/marker/trait.CoerceUnsized.html
+    fn try_coerce_unsized(&mut self, from_ty: &Ty, to_ty: &Ty) -> Option<bool> {
+        let (ctor1, st1, ctor2, st2) = match (from_ty, to_ty) {
+            (ty_app!(ctor1, st1), ty_app!(ctor2, st2)) => (ctor1, st1, ctor2, st2),
+            _ => return None,
+        };
+
+        let coerce_generic_index = *self.coerce_unsized_map.get(&(*ctor1, *ctor2))?;
+
+        // Check `Unsize` first
+        match self.check_unsize_and_coerce(
+            st1.0.get(coerce_generic_index)?,
+            st2.0.get(coerce_generic_index)?,
+            0,
+        ) {
+            Some(true) => {}
+            ret => return ret,
+        }
+
+        let ret = st1
+            .iter()
+            .zip(st2.iter())
+            .enumerate()
+            .filter(|&(idx, _)| idx != coerce_generic_index)
+            .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
+
+        Some(ret)
+    }
+
+    /// Check if `from_ty: Unsize<to_ty>`, and coerce to `to_ty` if it holds.
+    ///
+    /// It should not be directly called. It is only used by `try_coerce_unsized`.
+    ///
+    /// See: https://doc.rust-lang.org/nightly/std/marker/trait.Unsize.html
+    fn check_unsize_and_coerce(&mut self, from_ty: &Ty, to_ty: &Ty, depth: usize) -> Option<bool> {
+        if depth > 1000 {
+            panic!("Infinite recursion in coercion");
+        }
+
+        match (&from_ty, &to_ty) {
+            // `[T; N]` -> `[T]`
+            (ty_app!(TypeCtor::Array, st1), ty_app!(TypeCtor::Slice, st2)) => {
+                Some(self.unify(&st1[0], &st2[0]))
+            }
+
+            // `T` -> `dyn Trait` when `T: Trait`
+            (_, Ty::Dyn(_)) => {
+                // FIXME: Check predicates
+                Some(true)
+            }
+
+            // `(..., T)` -> `(..., U)` when `T: Unsize<U>`
+            (
+                ty_app!(TypeCtor::Tuple { cardinality: len1 }, st1),
+                ty_app!(TypeCtor::Tuple { cardinality: len2 }, st2),
+            ) => {
+                if len1 != len2 || *len1 == 0 {
+                    return None;
+                }
+
+                match self.check_unsize_and_coerce(
+                    st1.last().unwrap(),
+                    st2.last().unwrap(),
+                    depth + 1,
+                ) {
+                    Some(true) => {}
+                    ret => return ret,
+                }
+
+                let ret = st1[..st1.len() - 1]
+                    .iter()
+                    .zip(&st2[..st2.len() - 1])
+                    .all(|(ty1, ty2)| self.unify(ty1, ty2));
+
+                Some(ret)
+            }
+
+            // Foo<..., T, ...> is Unsize<Foo<..., U, ...>> if:
+            // - T: Unsize<U>
+            // - Foo is a struct
+            // - Only the last field of Foo has a type involving T
+            // - T is not part of the type of any other fields
+            // - Bar<T>: Unsize<Bar<U>>, if the last field of Foo has type Bar<T>
+            (
+                ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
+                ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
+            ) if struct1 == struct2 => {
+                let fields = struct1.fields(self.db);
+                let (last_field, prev_fields) = fields.split_last()?;
+
+                // Get the generic parameter involved in the last field.
+                let unsize_generic_index = {
+                    let mut index = None;
+                    let mut multiple_param = false;
+                    last_field.ty(self.db).walk(&mut |ty| match ty {
+                        &Ty::Param { idx, .. } => {
+                            if index.is_none() {
+                                index = Some(idx);
+                            } else if Some(idx) != index {
+                                multiple_param = true;
+                            }
+                        }
+                        _ => {}
+                    });
+
+                    if multiple_param {
+                        return None;
+                    }
+                    index?
+                };
+
+                // Check other fields do not involve it.
+                let mut multiple_used = false;
+                prev_fields.iter().for_each(|field| {
+                    field.ty(self.db).walk(&mut |ty| match ty {
+                        &Ty::Param { idx, .. } if idx == unsize_generic_index => {
+                            multiple_used = true
+                        }
+                        _ => {}
+                    })
+                });
+                if multiple_used {
+                    return None;
+                }
+
+                let unsize_generic_index = unsize_generic_index as usize;
+
+                // Check `Unsize` first
+                match self.check_unsize_and_coerce(
+                    st1.get(unsize_generic_index)?,
+                    st2.get(unsize_generic_index)?,
+                    depth + 1,
+                ) {
+                    Some(true) => {}
+                    ret => return ret,
+                }
+
+                // Then unify other parameters
+                let ret = st1
+                    .iter()
+                    .zip(st2.iter())
+                    .enumerate()
+                    .filter(|&(idx, _)| idx != unsize_generic_index)
+                    .all(|(_, (ty1, ty2))| self.unify(ty1, ty2));
+
+                Some(ret)
+            }
+
+            _ => None,
+        }
+    }
+
+    /// Unify `from_ty` to `to_ty` with optional auto Deref
+    ///
+    /// Note that the parameters are already stripped the outer reference.
+    fn unify_autoderef_behind_ref(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
+        let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
+        let to_ty = self.resolve_ty_shallow(&to_ty);
+        // FIXME: Auto DerefMut
+        for derefed_ty in
+            autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
+        {
+            let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
+            match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
+                // Stop when constructor matches.
+                (ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => {
+                    // It will not recurse to `coerce`.
+                    return self.unify_substs(st1, st2, 0);
+                }
+                _ => {}
+            }
+        }
+
+        false
+    }
+}
diff --git a/crates/ra_hir/src/ty/infer/expr.rs b/crates/ra_hir/src/ty/infer/expr.rs
new file mode 100644
index 000000000..f8807c742
--- /dev/null
+++ b/crates/ra_hir/src/ty/infer/expr.rs
@@ -0,0 +1,658 @@
+//! Type inference for expressions.
+
+use std::iter::{repeat, repeat_with};
+use std::sync::Arc;
+
+use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
+use crate::{
+    db::HirDatabase,
+    expr::{self, Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
+    generics::{GenericParams, HasGenericParams},
+    name,
+    nameres::Namespace,
+    path::{GenericArg, GenericArgs},
+    ty::{
+        autoderef, method_resolution, op, primitive, CallableDef, InferTy, Mutability, Obligation,
+        ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
+    },
+    Adt, Name,
+};
+
+impl<'a, D: HirDatabase> InferenceContext<'a, D> {
+    pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
+        let ty = self.infer_expr_inner(tgt_expr, expected);
+        let could_unify = self.unify(&ty, &expected.ty);
+        if !could_unify {
+            self.result.type_mismatches.insert(
+                tgt_expr,
+                TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
+            );
+        }
+        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        ty
+    }
+
+    /// Infer type of expression with possibly implicit coerce to the expected type.
+    /// Return the type after possible coercion.
+    fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
+        let ty = self.infer_expr_inner(expr, &expected);
+        let ty = if !self.coerce(&ty, &expected.ty) {
+            self.result
+                .type_mismatches
+                .insert(expr, TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() });
+            // Return actual type when type mismatch.
+            // This is needed for diagnostic when return type mismatch.
+            ty
+        } else if expected.ty == Ty::Unknown {
+            ty
+        } else {
+            expected.ty.clone()
+        };
+
+        self.resolve_ty_as_possible(&mut vec![], ty)
+    }
+
+    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] {
+            Expr::Missing => Ty::Unknown,
+            Expr::If { condition, then_branch, else_branch } => {
+                // if let is desugared to match, so this is always simple if
+                self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
+
+                let then_ty = self.infer_expr_inner(*then_branch, &expected);
+                let else_ty = match else_branch {
+                    Some(else_branch) => self.infer_expr_inner(*else_branch, &expected),
+                    None => Ty::unit(),
+                };
+
+                self.coerce_merge_branch(&then_ty, &else_ty)
+            }
+            Expr::Block { statements, tail } => self.infer_block(statements, *tail, expected),
+            Expr::TryBlock { body } => {
+                let _inner = self.infer_expr(*body, expected);
+                // FIXME should be std::result::Result<{inner}, _>
+                Ty::Unknown
+            }
+            Expr::Loop { body } => {
+                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
+                // FIXME handle break with value
+                Ty::simple(TypeCtor::Never)
+            }
+            Expr::While { condition, body } => {
+                // while let is desugared to a match loop, so this is always simple while
+                self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool)));
+                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
+                Ty::unit()
+            }
+            Expr::For { iterable, body, pat } => {
+                let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
+
+                let pat_ty = match self.resolve_into_iter_item() {
+                    Some(into_iter_item_alias) => {
+                        let pat_ty = self.new_type_var();
+                        let projection = ProjectionPredicate {
+                            ty: pat_ty.clone(),
+                            projection_ty: ProjectionTy {
+                                associated_ty: into_iter_item_alias,
+                                parameters: Substs::single(iterable_ty),
+                            },
+                        };
+                        self.obligations.push(Obligation::Projection(projection));
+                        self.resolve_ty_as_possible(&mut vec![], pat_ty)
+                    }
+                    None => Ty::Unknown,
+                };
+
+                self.infer_pat(*pat, &pat_ty, BindingMode::default());
+                self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
+                Ty::unit()
+            }
+            Expr::Lambda { body, args, arg_types } => {
+                assert_eq!(args.len(), arg_types.len());
+
+                let mut sig_tys = Vec::new();
+
+                for (arg_pat, arg_type) in args.iter().zip(arg_types.iter()) {
+                    let expected = if let Some(type_ref) = arg_type {
+                        self.make_ty(type_ref)
+                    } else {
+                        Ty::Unknown
+                    };
+                    let arg_ty = self.infer_pat(*arg_pat, &expected, BindingMode::default());
+                    sig_tys.push(arg_ty);
+                }
+
+                // add return type
+                let ret_ty = self.new_type_var();
+                sig_tys.push(ret_ty.clone());
+                let sig_ty = Ty::apply(
+                    TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
+                    Substs(sig_tys.into()),
+                );
+                let closure_ty = Ty::apply_one(
+                    TypeCtor::Closure { def: self.body.owner(), expr: tgt_expr },
+                    sig_ty,
+                );
+
+                // Eagerly try to relate the closure type with the expected
+                // type, otherwise we often won't have enough information to
+                // infer the body.
+                self.coerce(&closure_ty, &expected.ty);
+
+                self.infer_expr(*body, &Expectation::has_type(ret_ty));
+                closure_ty
+            }
+            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)
+                    }
+                };
+                self.register_obligations_for_call(&callee_ty);
+                self.check_call_arguments(args, &param_tys);
+                let ret_ty = self.normalize_associated_types_in(ret_ty);
+                ret_ty
+            }
+            Expr::MethodCall { receiver, args, method_name, generic_args } => self
+                .infer_method_call(tgt_expr, *receiver, &args, &method_name, generic_args.as_ref()),
+            Expr::Match { expr, arms } => {
+                let input_ty = self.infer_expr(*expr, &Expectation::none());
+
+                let mut result_ty = self.new_maybe_never_type_var();
+
+                for arm in arms {
+                    for &pat in &arm.pats {
+                        let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default());
+                    }
+                    if let Some(guard_expr) = arm.guard {
+                        self.infer_expr(
+                            guard_expr,
+                            &Expectation::has_type(Ty::simple(TypeCtor::Bool)),
+                        );
+                    }
+
+                    let arm_ty = self.infer_expr_inner(arm.expr, &expected);
+                    result_ty = self.coerce_merge_branch(&result_ty, &arm_ty);
+                }
+
+                result_ty
+            }
+            Expr::Path(p) => {
+                // FIXME this could be more efficient...
+                let resolver = expr::resolver_for_expr(self.body.clone(), self.db, tgt_expr);
+                self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or(Ty::Unknown)
+            }
+            Expr::Continue => Ty::simple(TypeCtor::Never),
+            Expr::Break { expr } => {
+                if let Some(expr) = expr {
+                    // FIXME handle break with value
+                    self.infer_expr(*expr, &Expectation::none());
+                }
+                Ty::simple(TypeCtor::Never)
+            }
+            Expr::Return { expr } => {
+                if let Some(expr) = expr {
+                    self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
+                }
+                Ty::simple(TypeCtor::Never)
+            }
+            Expr::RecordLit { path, fields, spread } => {
+                let (ty, def_id) = self.resolve_variant(path.as_ref());
+                if let Some(variant) = def_id {
+                    self.write_variant_resolution(tgt_expr.into(), variant);
+                }
+
+                self.unify(&ty, &expected.ty);
+
+                let substs = ty.substs().unwrap_or_else(Substs::empty);
+                for (field_idx, field) in fields.iter().enumerate() {
+                    let field_ty = def_id
+                        .and_then(|it| match it.field(self.db, &field.name) {
+                            Some(field) => Some(field),
+                            None => {
+                                self.push_diagnostic(InferenceDiagnostic::NoSuchField {
+                                    expr: tgt_expr,
+                                    field: field_idx,
+                                });
+                                None
+                            }
+                        })
+                        .map_or(Ty::Unknown, |field| field.ty(self.db))
+                        .subst(&substs);
+                    self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
+                }
+                if let Some(expr) = spread {
+                    self.infer_expr(*expr, &Expectation::has_type(ty.clone()));
+                }
+                ty
+            }
+            Expr::Field { expr, name } => {
+                let receiver_ty = self.infer_expr(*expr, &Expectation::none());
+                let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
+                let ty = autoderef::autoderef(
+                    self.db,
+                    &self.resolver.clone(),
+                    canonicalized.value.clone(),
+                )
+                .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
+                    Ty::Apply(a_ty) => match a_ty.ctor {
+                        TypeCtor::Tuple { .. } => name
+                            .as_tuple_index()
+                            .and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
+                        TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
+                            self.write_field_resolution(tgt_expr, field);
+                            field.ty(self.db).subst(&a_ty.parameters)
+                        }),
+                        _ => None,
+                    },
+                    _ => None,
+                })
+                .unwrap_or(Ty::Unknown);
+                let ty = self.insert_type_vars(ty);
+                self.normalize_associated_types_in(ty)
+            }
+            Expr::Await { expr } => {
+                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let ty = match self.resolve_future_future_output() {
+                    Some(future_future_output_alias) => {
+                        let ty = self.new_type_var();
+                        let projection = ProjectionPredicate {
+                            ty: ty.clone(),
+                            projection_ty: ProjectionTy {
+                                associated_ty: future_future_output_alias,
+                                parameters: Substs::single(inner_ty),
+                            },
+                        };
+                        self.obligations.push(Obligation::Projection(projection));
+                        self.resolve_ty_as_possible(&mut vec![], ty)
+                    }
+                    None => Ty::Unknown,
+                };
+                ty
+            }
+            Expr::Try { expr } => {
+                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let ty = match self.resolve_ops_try_ok() {
+                    Some(ops_try_ok_alias) => {
+                        let ty = self.new_type_var();
+                        let projection = ProjectionPredicate {
+                            ty: ty.clone(),
+                            projection_ty: ProjectionTy {
+                                associated_ty: ops_try_ok_alias,
+                                parameters: Substs::single(inner_ty),
+                            },
+                        };
+                        self.obligations.push(Obligation::Projection(projection));
+                        self.resolve_ty_as_possible(&mut vec![], ty)
+                    }
+                    None => Ty::Unknown,
+                };
+                ty
+            }
+            Expr::Cast { expr, type_ref } => {
+                let _inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let cast_ty = self.make_ty(type_ref);
+                // FIXME check the cast...
+                cast_ty
+            }
+            Expr::Ref { expr, mutability } => {
+                let expectation =
+                    if let Some((exp_inner, exp_mutability)) = &expected.ty.as_reference() {
+                        if *exp_mutability == Mutability::Mut && *mutability == Mutability::Shared {
+                            // FIXME: throw type error - expected mut reference but found shared ref,
+                            // which cannot be coerced
+                        }
+                        Expectation::has_type(Ty::clone(exp_inner))
+                    } else {
+                        Expectation::none()
+                    };
+                // FIXME reference coercions etc.
+                let inner_ty = self.infer_expr(*expr, &expectation);
+                Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
+            }
+            Expr::Box { expr } => {
+                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                if let Some(box_) = self.resolve_boxed_box() {
+                    Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
+                } else {
+                    Ty::Unknown
+                }
+            }
+            Expr::UnaryOp { expr, op } => {
+                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                match op {
+                    UnaryOp::Deref => {
+                        let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty);
+                        if let Some(derefed_ty) =
+                            autoderef::deref(self.db, &self.resolver, &canonicalized.value)
+                        {
+                            canonicalized.decanonicalize_ty(derefed_ty.value)
+                        } else {
+                            Ty::Unknown
+                        }
+                    }
+                    UnaryOp::Neg => {
+                        match &inner_ty {
+                            Ty::Apply(a_ty) => match a_ty.ctor {
+                                TypeCtor::Int(primitive::UncertainIntTy::Unknown)
+                                | TypeCtor::Int(primitive::UncertainIntTy::Known(
+                                    primitive::IntTy {
+                                        signedness: primitive::Signedness::Signed,
+                                        ..
+                                    },
+                                ))
+                                | TypeCtor::Float(..) => inner_ty,
+                                _ => Ty::Unknown,
+                            },
+                            Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => {
+                                inner_ty
+                            }
+                            // FIXME: resolve ops::Neg trait
+                            _ => Ty::Unknown,
+                        }
+                    }
+                    UnaryOp::Not => {
+                        match &inner_ty {
+                            Ty::Apply(a_ty) => match a_ty.ctor {
+                                TypeCtor::Bool | TypeCtor::Int(_) => inner_ty,
+                                _ => Ty::Unknown,
+                            },
+                            Ty::Infer(InferTy::IntVar(..)) => inner_ty,
+                            // FIXME: resolve ops::Not trait for inner_ty
+                            _ => Ty::Unknown,
+                        }
+                    }
+                }
+            }
+            Expr::BinaryOp { lhs, rhs, op } => match op {
+                Some(op) => {
+                    let lhs_expectation = match op {
+                        BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)),
+                        _ => Expectation::none(),
+                    };
+                    let lhs_ty = self.infer_expr(*lhs, &lhs_expectation);
+                    // FIXME: find implementation of trait corresponding to operation
+                    // symbol and resolve associated `Output` type
+                    let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty);
+                    let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation));
+
+                    // FIXME: similar as above, return ty is often associated trait type
+                    op::binary_op_return_ty(*op, rhs_ty)
+                }
+                _ => Ty::Unknown,
+            },
+            Expr::Index { base, index } => {
+                let _base_ty = self.infer_expr(*base, &Expectation::none());
+                let _index_ty = self.infer_expr(*index, &Expectation::none());
+                // FIXME: use `std::ops::Index::Output` to figure out the real return type
+                Ty::Unknown
+            }
+            Expr::Tuple { exprs } => {
+                let mut tys = match &expected.ty {
+                    ty_app!(TypeCtor::Tuple { .. }, st) => st
+                        .iter()
+                        .cloned()
+                        .chain(repeat_with(|| self.new_type_var()))
+                        .take(exprs.len())
+                        .collect::<Vec<_>>(),
+                    _ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
+                };
+
+                for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
+                    self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone()));
+                }
+
+                Ty::apply(TypeCtor::Tuple { cardinality: tys.len() as u16 }, Substs(tys.into()))
+            }
+            Expr::Array(array) => {
+                let elem_ty = match &expected.ty {
+                    ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
+                        st.as_single().clone()
+                    }
+                    _ => self.new_type_var(),
+                };
+
+                match array {
+                    Array::ElementList(items) => {
+                        for expr in items.iter() {
+                            self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone()));
+                        }
+                    }
+                    Array::Repeat { initializer, repeat } => {
+                        self.infer_expr_coerce(
+                            *initializer,
+                            &Expectation::has_type(elem_ty.clone()),
+                        );
+                        self.infer_expr(
+                            *repeat,
+                            &Expectation::has_type(Ty::simple(TypeCtor::Int(
+                                primitive::UncertainIntTy::Known(primitive::IntTy::usize()),
+                            ))),
+                        );
+                    }
+                }
+
+                Ty::apply_one(TypeCtor::Array, elem_ty)
+            }
+            Expr::Literal(lit) => match lit {
+                Literal::Bool(..) => Ty::simple(TypeCtor::Bool),
+                Literal::String(..) => {
+                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
+                }
+                Literal::ByteString(..) => {
+                    let byte_type = Ty::simple(TypeCtor::Int(primitive::UncertainIntTy::Known(
+                        primitive::IntTy::u8(),
+                    )));
+                    let slice_type = Ty::apply_one(TypeCtor::Slice, byte_type);
+                    Ty::apply_one(TypeCtor::Ref(Mutability::Shared), slice_type)
+                }
+                Literal::Char(..) => Ty::simple(TypeCtor::Char),
+                Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int(*ty)),
+                Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float(*ty)),
+            },
+        };
+        // use a new type variable if we got Ty::Unknown here
+        let ty = self.insert_type_vars_shallow(ty);
+        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        self.write_expr_ty(tgt_expr, ty.clone());
+        ty
+    }
+
+    fn infer_block(
+        &mut self,
+        statements: &[Statement],
+        tail: Option<ExprId>,
+        expected: &Expectation,
+    ) -> Ty {
+        let mut diverges = false;
+        for stmt in statements {
+            match stmt {
+                Statement::Let { pat, type_ref, initializer } => {
+                    let decl_ty =
+                        type_ref.as_ref().map(|tr| self.make_ty(tr)).unwrap_or(Ty::Unknown);
+
+                    // Always use the declared type when specified
+                    let mut ty = decl_ty.clone();
+
+                    if let Some(expr) = initializer {
+                        let actual_ty =
+                            self.infer_expr_coerce(*expr, &Expectation::has_type(decl_ty.clone()));
+                        if decl_ty == Ty::Unknown {
+                            ty = actual_ty;
+                        }
+                    }
+
+                    let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+                    self.infer_pat(*pat, &ty, BindingMode::default());
+                }
+                Statement::Expr(expr) => {
+                    if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
+                        diverges = true;
+                    }
+                }
+            }
+        }
+
+        let ty = if let Some(expr) = tail {
+            self.infer_expr_coerce(expr, expected)
+        } else {
+            self.coerce(&Ty::unit(), &expected.ty);
+            Ty::unit()
+        };
+        if diverges {
+            Ty::simple(TypeCtor::Never)
+        } else {
+            ty
+        }
+    }
+
+    fn infer_method_call(
+        &mut self,
+        tgt_expr: ExprId,
+        receiver: ExprId,
+        args: &[ExprId],
+        method_name: &Name,
+        generic_args: Option<&GenericArgs>,
+    ) -> Ty {
+        let receiver_ty = self.infer_expr(receiver, &Expectation::none());
+        let canonicalized_receiver = self.canonicalizer().canonicalize_ty(receiver_ty.clone());
+        let resolved = method_resolution::lookup_method(
+            &canonicalized_receiver.value,
+            self.db,
+            method_name,
+            &self.resolver,
+        );
+        let (derefed_receiver_ty, method_ty, def_generics) = match resolved {
+            Some((ty, func)) => {
+                let ty = canonicalized_receiver.decanonicalize_ty(ty);
+                self.write_method_resolution(tgt_expr, func);
+                (
+                    ty,
+                    self.db.type_for_def(func.into(), Namespace::Values),
+                    Some(func.generic_params(self.db)),
+                )
+            }
+            None => (receiver_ty, Ty::Unknown, None),
+        };
+        let substs = self.substs_for_method_call(def_generics, generic_args, &derefed_receiver_ty);
+        let method_ty = method_ty.apply_substs(substs);
+        let method_ty = self.insert_type_vars(method_ty);
+        self.register_obligations_for_call(&method_ty);
+        let (expected_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) {
+            Some(sig) => {
+                if !sig.params().is_empty() {
+                    (sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone())
+                } else {
+                    (Ty::Unknown, Vec::new(), sig.ret().clone())
+                }
+            }
+            None => (Ty::Unknown, Vec::new(), Ty::Unknown),
+        };
+        // Apply autoref so the below unification works correctly
+        // FIXME: return correct autorefs from lookup_method
+        let actual_receiver_ty = match expected_receiver_ty.as_reference() {
+            Some((_, mutability)) => Ty::apply_one(TypeCtor::Ref(mutability), derefed_receiver_ty),
+            _ => derefed_receiver_ty,
+        };
+        self.unify(&expected_receiver_ty, &actual_receiver_ty);
+
+        self.check_call_arguments(args, &param_tys);
+        let ret_ty = self.normalize_associated_types_in(ret_ty);
+        ret_ty
+    }
+
+    fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) {
+        // Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 --
+        // We do this in a pretty awful way: first we type-check any arguments
+        // that are not closures, then we type-check the closures. This is so
+        // that we have more information about the types of arguments when we
+        // type-check the functions. This isn't really the right way to do this.
+        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,
+                };
+
+                if is_closure != check_closures {
+                    continue;
+                }
+
+                let param_ty = self.normalize_associated_types_in(param_ty);
+                self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
+            }
+        }
+    }
+
+    fn substs_for_method_call(
+        &mut self,
+        def_generics: Option<Arc<GenericParams>>,
+        generic_args: Option<&GenericArgs>,
+        receiver_ty: &Ty,
+    ) -> Substs {
+        let (parent_param_count, param_count) =
+            def_generics.as_ref().map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
+        let mut substs = Vec::with_capacity(parent_param_count + param_count);
+        // Parent arguments are unknown, except for the receiver type
+        if let Some(parent_generics) = def_generics.and_then(|p| p.parent_params.clone()) {
+            for param in &parent_generics.params {
+                if param.name == name::SELF_TYPE {
+                    substs.push(receiver_ty.clone());
+                } else {
+                    substs.push(Ty::Unknown);
+                }
+            }
+        }
+        // handle provided type arguments
+        if let Some(generic_args) = generic_args {
+            // if args are provided, it should be all of them, but we can't rely on that
+            for arg in generic_args.args.iter().take(param_count) {
+                match arg {
+                    GenericArg::Type(type_ref) => {
+                        let ty = self.make_ty(type_ref);
+                        substs.push(ty);
+                    }
+                }
+            }
+        };
+        let supplied_params = substs.len();
+        for _ in supplied_params..parent_param_count + param_count {
+            substs.push(Ty::Unknown);
+        }
+        assert_eq!(substs.len(), parent_param_count + param_count);
+        Substs(substs.into())
+    }
+
+    fn register_obligations_for_call(&mut self, callable_ty: &Ty) {
+        if let Ty::Apply(a_ty) = callable_ty {
+            if let TypeCtor::FnDef(def) = a_ty.ctor {
+                let generic_predicates = self.db.generic_predicates(def.into());
+                for predicate in generic_predicates.iter() {
+                    let predicate = predicate.clone().subst(&a_ty.parameters);
+                    if let Some(obligation) = Obligation::from_predicate(predicate) {
+                        self.obligations.push(obligation);
+                    }
+                }
+                // add obligation for trait implementation, if this is a trait method
+                match def {
+                    CallableDef::Function(f) => {
+                        if let Some(trait_) = f.parent_trait(self.db) {
+                            // construct a TraitDef
+                            let substs = a_ty.parameters.prefix(
+                                trait_.generic_params(self.db).count_params_including_parent(),
+                            );
+                            self.obligations.push(Obligation::Trait(TraitRef { trait_, substs }));
+                        }
+                    }
+                    CallableDef::Struct(_) | CallableDef::EnumVariant(_) => {}
+                }
+            }
+        }
+    }
+}
diff --git a/crates/ra_hir/src/ty/infer/pat.rs b/crates/ra_hir/src/ty/infer/pat.rs
new file mode 100644
index 000000000..c125ddfbc
--- /dev/null
+++ b/crates/ra_hir/src/ty/infer/pat.rs
@@ -0,0 +1,180 @@
+//! Type inference for patterns.
+
+use std::iter::repeat;
+use std::sync::Arc;
+
+use test_utils::tested_by;
+
+use super::{BindingMode, InferenceContext};
+use crate::{
+    db::HirDatabase,
+    expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
+    ty::{Mutability, Substs, Ty, TypeCtor, TypeWalk},
+    Name, Path,
+};
+
+impl<'a, D: HirDatabase> InferenceContext<'a, D> {
+    fn infer_tuple_struct_pat(
+        &mut self,
+        path: Option<&Path>,
+        subpats: &[PatId],
+        expected: &Ty,
+        default_bm: BindingMode,
+    ) -> Ty {
+        let (ty, def) = self.resolve_variant(path);
+
+        self.unify(&ty, expected);
+
+        let substs = ty.substs().unwrap_or_else(Substs::empty);
+
+        for (i, &subpat) in subpats.iter().enumerate() {
+            let expected_ty = def
+                .and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
+                .map_or(Ty::Unknown, |field| field.ty(self.db))
+                .subst(&substs);
+            let expected_ty = self.normalize_associated_types_in(expected_ty);
+            self.infer_pat(subpat, &expected_ty, default_bm);
+        }
+
+        ty
+    }
+
+    fn infer_record_pat(
+        &mut self,
+        path: Option<&Path>,
+        subpats: &[RecordFieldPat],
+        expected: &Ty,
+        default_bm: BindingMode,
+        id: PatId,
+    ) -> Ty {
+        let (ty, def) = self.resolve_variant(path);
+        if let Some(variant) = def {
+            self.write_variant_resolution(id.into(), variant);
+        }
+
+        self.unify(&ty, expected);
+
+        let substs = ty.substs().unwrap_or_else(Substs::empty);
+
+        for subpat in subpats {
+            let matching_field = def.and_then(|it| it.field(self.db, &subpat.name));
+            let expected_ty =
+                matching_field.map_or(Ty::Unknown, |field| field.ty(self.db)).subst(&substs);
+            let expected_ty = self.normalize_associated_types_in(expected_ty);
+            self.infer_pat(subpat.pat, &expected_ty, default_bm);
+        }
+
+        ty
+    }
+
+    pub(super) fn infer_pat(
+        &mut self,
+        pat: PatId,
+        mut expected: &Ty,
+        mut default_bm: BindingMode,
+    ) -> Ty {
+        let body = Arc::clone(&self.body); // avoid borrow checker problem
+
+        let is_non_ref_pat = match &body[pat] {
+            Pat::Tuple(..)
+            | 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 {
+            while let Some((inner, mutability)) = expected.as_reference() {
+                expected = inner;
+                default_bm = match default_bm {
+                    BindingMode::Move => BindingMode::Ref(mutability),
+                    BindingMode::Ref(Mutability::Shared) => BindingMode::Ref(Mutability::Shared),
+                    BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability),
+                }
+            }
+        } else if let Pat::Ref { .. } = &body[pat] {
+            tested_by!(match_ergonomics_ref);
+            // When you encounter a `&pat` pattern, reset to Move.
+            // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
+            default_bm = BindingMode::Move;
+        }
+
+        // Lose mutability.
+        let default_bm = default_bm;
+        let expected = expected;
+
+        let ty = match &body[pat] {
+            Pat::Tuple(ref args) => {
+                let expectations = match expected.as_tuple() {
+                    Some(parameters) => &*parameters.0,
+                    _ => &[],
+                };
+                let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
+
+                let inner_tys = args
+                    .iter()
+                    .zip(expectations_iter)
+                    .map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm))
+                    .collect();
+
+                Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
+            }
+            Pat::Ref { pat, mutability } => {
+                let expectation = match expected.as_reference() {
+                    Some((inner_ty, exp_mut)) => {
+                        if *mutability != exp_mut {
+                            // FIXME: emit type error?
+                        }
+                        inner_ty
+                    }
+                    _ => &Ty::Unknown,
+                };
+                let subty = self.infer_pat(*pat, expectation, default_bm);
+                Ty::apply_one(TypeCtor::Ref(*mutability), subty)
+            }
+            Pat::TupleStruct { path: p, args: subpats } => {
+                self.infer_tuple_struct_pat(p.as_ref(), subpats, expected, default_bm)
+            }
+            Pat::Record { path: p, args: fields } => {
+                self.infer_record_pat(p.as_ref(), fields, expected, default_bm, pat)
+            }
+            Pat::Path(path) => {
+                // FIXME use correct resolver for the surrounding expression
+                let resolver = self.resolver.clone();
+                self.infer_path(&resolver, &path, pat.into()).unwrap_or(Ty::Unknown)
+            }
+            Pat::Bind { mode, name: _, subpat } => {
+                let mode = if mode == &BindingAnnotation::Unannotated {
+                    default_bm
+                } else {
+                    BindingMode::convert(*mode)
+                };
+                let inner_ty = if let Some(subpat) = subpat {
+                    self.infer_pat(*subpat, expected, default_bm)
+                } else {
+                    expected.clone()
+                };
+                let inner_ty = self.insert_type_vars_shallow(inner_ty);
+
+                let bound_ty = match mode {
+                    BindingMode::Ref(mutability) => {
+                        Ty::apply_one(TypeCtor::Ref(mutability), inner_ty.clone())
+                    }
+                    BindingMode::Move => inner_ty.clone(),
+                };
+                let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
+                self.write_pat_ty(pat, bound_ty);
+                return inner_ty;
+            }
+            _ => Ty::Unknown,
+        };
+        // use a new type variable if we got Ty::Unknown here
+        let ty = self.insert_type_vars_shallow(ty);
+        self.unify(&ty, expected);
+        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        self.write_pat_ty(pat, ty.clone());
+        ty
+    }
+}
diff --git a/crates/ra_hir/src/ty/infer/unify.rs b/crates/ra_hir/src/ty/infer/unify.rs
index d161aa6b3..ca33cc7f8 100644
--- a/crates/ra_hir/src/ty/infer/unify.rs
+++ b/crates/ra_hir/src/ty/infer/unify.rs
@@ -6,6 +6,7 @@ use crate::ty::{
     Canonical, InEnvironment, InferTy, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty,
     TypeWalk,
 };
+use crate::util::make_mut_slice;
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     pub(super) fn canonicalizer<'b>(&'b mut self) -> Canonicalizer<'a, 'b, D>
@@ -53,7 +54,9 @@ where
                     // recursive type
                     return tv.fallback_value();
                 }
-                if let Some(known_ty) = self.ctx.var_unification_table.probe_value(inner).known() {
+                if let Some(known_ty) =
+                    self.ctx.var_unification_table.inlined_probe_value(inner).known()
+                {
                     self.var_stack.push(inner);
                     let result = self.do_canonicalize_ty(known_ty.clone());
                     self.var_stack.pop();
@@ -74,10 +77,11 @@ where
         })
     }
 
-    fn do_canonicalize_trait_ref(&mut self, trait_ref: TraitRef) -> TraitRef {
-        let substs =
-            trait_ref.substs.iter().map(|ty| self.do_canonicalize_ty(ty.clone())).collect();
-        TraitRef { trait_: trait_ref.trait_, substs: Substs(substs) }
+    fn do_canonicalize_trait_ref(&mut self, mut trait_ref: TraitRef) -> TraitRef {
+        for ty in make_mut_slice(&mut trait_ref.substs.0) {
+            *ty = self.do_canonicalize_ty(ty.clone());
+        }
+        trait_ref
     }
 
     fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
@@ -87,10 +91,11 @@ where
         }
     }
 
-    fn do_canonicalize_projection_ty(&mut self, projection_ty: ProjectionTy) -> ProjectionTy {
-        let params =
-            projection_ty.parameters.iter().map(|ty| self.do_canonicalize_ty(ty.clone())).collect();
-        ProjectionTy { associated_ty: projection_ty.associated_ty, parameters: Substs(params) }
+    fn do_canonicalize_projection_ty(&mut self, mut projection_ty: ProjectionTy) -> ProjectionTy {
+        for ty in make_mut_slice(&mut projection_ty.parameters.0) {
+            *ty = self.do_canonicalize_ty(ty.clone());
+        }
+        projection_ty
     }
 
     fn do_canonicalize_projection_predicate(
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index 4b67c82e7..366556134 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -22,6 +22,7 @@ use crate::{
     resolve::{Resolver, TypeNs},
     ty::Adt,
     type_ref::{TypeBound, TypeRef},
+    util::make_mut_slice,
     BuiltinType, Const, Enum, EnumVariant, Function, ModuleDef, Path, Static, Struct, StructField,
     Trait, TypeAlias, Union,
 };
@@ -31,11 +32,11 @@ impl Ty {
         match type_ref {
             TypeRef::Never => Ty::simple(TypeCtor::Never),
             TypeRef::Tuple(inner) => {
-                let inner_tys =
-                    inner.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect::<Vec<_>>();
+                let inner_tys: Arc<[Ty]> =
+                    inner.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect();
                 Ty::apply(
                     TypeCtor::Tuple { cardinality: inner_tys.len() as u16 },
-                    Substs(inner_tys.into()),
+                    Substs(inner_tys),
                 )
             }
             TypeRef::Path(path) => Ty::from_hir_path(db, resolver, path),
@@ -57,9 +58,7 @@ impl Ty {
             }
             TypeRef::Placeholder => Ty::Unknown,
             TypeRef::Fn(params) => {
-                let inner_tys =
-                    params.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect::<Vec<_>>();
-                let sig = Substs(inner_tys.into());
+                let sig = Substs(params.iter().map(|tr| Ty::from_hir(db, resolver, tr)).collect());
                 Ty::apply(TypeCtor::FnPtr { num_args: sig.len() as u16 - 1 }, sig)
             }
             TypeRef::DynTrait(bounds) => {
@@ -69,8 +68,8 @@ impl Ty {
                     .flat_map(|b| {
                         GenericPredicate::from_type_bound(db, resolver, b, self_ty.clone())
                     })
-                    .collect::<Vec<_>>();
-                Ty::Dyn(predicates.into())
+                    .collect();
+                Ty::Dyn(predicates)
             }
             TypeRef::ImplTrait(bounds) => {
                 let self_ty = Ty::Bound(0);
@@ -79,8 +78,8 @@ impl Ty {
                     .flat_map(|b| {
                         GenericPredicate::from_type_bound(db, resolver, b, self_ty.clone())
                     })
-                    .collect::<Vec<_>>();
-                Ty::Opaque(predicates.into())
+                    .collect();
+                Ty::Opaque(predicates)
             }
             TypeRef::Error => Ty::Unknown,
         }
@@ -175,6 +174,7 @@ impl Ty {
                 Ty::Param { idx, name }
             }
             TypeNs::SelfType(impl_block) => impl_block.target_ty(db),
+            TypeNs::AdtSelfType(adt) => adt.ty(db),
 
             TypeNs::Adt(it) => Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into()),
             TypeNs::BuiltinType(it) => {
@@ -391,10 +391,7 @@ impl TraitRef {
     ) -> Self {
         let mut substs = TraitRef::substs_from_path(db, resolver, segment, resolved);
         if let Some(self_ty) = explicit_self_ty {
-            // FIXME this could be nicer
-            let mut substs_vec = substs.0.to_vec();
-            substs_vec[0] = self_ty;
-            substs.0 = substs_vec.into();
+            make_mut_slice(&mut substs.0)[0] = self_ty;
         }
         TraitRef { trait_: resolved, substs }
     }
@@ -557,13 +554,12 @@ pub(crate) fn generic_predicates_for_param_query(
     param_idx: u32,
 ) -> Arc<[GenericPredicate]> {
     let resolver = def.resolver(db);
-    let predicates = resolver
+    resolver
         .where_predicates_in_scope()
         // we have to filter out all other predicates *first*, before attempting to lower them
         .filter(|pred| Ty::from_hir_only_param(db, &resolver, &pred.type_ref) == Some(param_idx))
         .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
-        .collect::<Vec<_>>();
-    predicates.into()
+        .collect()
 }
 
 pub(crate) fn trait_env(
@@ -584,11 +580,10 @@ pub(crate) fn generic_predicates_query(
     def: GenericDef,
 ) -> Arc<[GenericPredicate]> {
     let resolver = def.resolver(db);
-    let predicates = resolver
+    resolver
         .where_predicates_in_scope()
         .flat_map(|pred| GenericPredicate::from_where_predicate(db, &resolver, pred))
-        .collect::<Vec<_>>();
-    predicates.into()
+        .collect()
 }
 
 /// Resolve the default type params from generics
@@ -602,9 +597,9 @@ pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDef) ->
         .map(|p| {
             p.default.as_ref().map_or(Ty::Unknown, |path| Ty::from_hir_path(db, &resolver, path))
         })
-        .collect::<Vec<_>>();
+        .collect();
 
-    Substs(defaults.into())
+    Substs(defaults)
 }
 
 fn fn_sig_for_fn(db: &impl HirDatabase, def: Function) -> FnSig {
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 25dad81eb..c12326643 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -3,7 +3,6 @@ use std::sync::Arc;
 
 use insta::assert_snapshot;
 
-use ra_cfg::CfgOptions;
 use ra_db::{salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
@@ -62,7 +61,7 @@ impl S {
 "#,
     );
     db.set_crate_graph_from_fixture(crate_graph! {
-        "main": ("/main.rs", ["foo"], CfgOptions::default().atom("test".into())),
+        "main": ("/main.rs", ["foo"], cfg = { "test" }),
         "foo": ("/foo.rs", []),
     });
     assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
@@ -135,6 +134,25 @@ mod boxed {
 }
 
 #[test]
+fn infer_adt_self() {
+    let (db, pos) = MockDatabase::with_position(
+        r#"
+//- /main.rs
+enum Nat { Succ(Self), Demo(Nat), Zero }
+
+fn test() {
+    let foo: Nat = Nat::Zero;
+    if let Nat::Succ(x) = foo {
+        x<|>
+    }
+}
+
+"#,
+    );
+    assert_eq!("Nat", type_at_pos(&db, pos));
+}
+
+#[test]
 fn infer_try() {
     let (mut db, pos) = MockDatabase::with_position(
         r#"
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index b0f67ae50..0cb5c3798 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -89,7 +89,7 @@ pub(crate) fn impls_for_trait_query(
     }
     let crate_impl_blocks = db.impls_in_crate(krate);
     impls.extend(crate_impl_blocks.lookup_impl_blocks_for_trait(trait_));
-    impls.into_iter().collect::<Vec<_>>().into()
+    impls.into_iter().collect()
 }
 
 /// A set of clauses that we assume to be true. E.g. if we are inside this function:
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 2642a54bf..00aaf65d9 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -126,8 +126,7 @@ impl ToChalk for Substs {
                 chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
                 chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
             })
-            .collect::<Vec<_>>()
-            .into();
+            .collect();
         Substs(tys)
     }
 }
@@ -491,15 +490,16 @@ pub(crate) fn trait_datum_query(
             },
             associated_ty_ids: Vec::new(),
             where_clauses: Vec::new(),
-            flags: chalk_rust_ir::TraitFlags {
-                non_enumerable: true,
-                auto: false,
-                marker: false,
-                upstream: true,
-                fundamental: false,
-            },
         };
-        return Arc::new(TraitDatum { binders: make_binders(trait_datum_bound, 1) });
+
+        let flags = chalk_rust_ir::TraitFlags {
+            auto: false,
+            marker: false,
+            upstream: true,
+            fundamental: false,
+            non_enumerable: true,
+        };
+        return Arc::new(TraitDatum { binders: make_binders(trait_datum_bound, 1), flags });
     }
     let trait_: Trait = from_chalk(db, trait_id);
     debug!("trait {:?} = {:?}", trait_id, trait_.name(db));
@@ -525,8 +525,9 @@ pub(crate) fn trait_datum_query(
         .map(|type_alias| type_alias.to_chalk(db))
         .collect();
     let trait_datum_bound =
-        chalk_rust_ir::TraitDatumBound { trait_ref, where_clauses, flags, associated_ty_ids };
-    let trait_datum = TraitDatum { binders: make_binders(trait_datum_bound, bound_vars.len()) };
+        chalk_rust_ir::TraitDatumBound { trait_ref, where_clauses, associated_ty_ids };
+    let trait_datum =
+        TraitDatum { binders: make_binders(trait_datum_bound, bound_vars.len()), flags };
     Arc::new(trait_datum)
 }
 
@@ -632,18 +633,20 @@ fn impl_block_datum(
         })
         .collect();
 
-    let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
-        trait_ref: if negative {
-            chalk_rust_ir::PolarizedTraitRef::Negative(trait_ref)
-        } else {
-            chalk_rust_ir::PolarizedTraitRef::Positive(trait_ref)
-        },
-        where_clauses,
-        associated_ty_values,
-        impl_type,
+    let polarity = if negative {
+        chalk_rust_ir::Polarity::Negative
+    } else {
+        chalk_rust_ir::Polarity::Positive
     };
+
+    let impl_datum_bound =
+        chalk_rust_ir::ImplDatumBound { trait_ref, where_clauses, associated_ty_values };
     debug!("impl_datum: {:?}", impl_datum_bound);
-    let impl_datum = ImplDatum { binders: make_binders(impl_datum_bound, bound_vars.len()) };
+    let impl_datum = ImplDatum {
+        binders: make_binders(impl_datum_bound, bound_vars.len()),
+        impl_type,
+        polarity,
+    };
     Arc::new(impl_datum)
 }
 
@@ -653,12 +656,15 @@ fn invalid_impl_datum() -> Arc<ImplDatum> {
         parameters: vec![chalk_ir::Ty::BoundVar(0).cast()],
     };
     let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
-        trait_ref: chalk_rust_ir::PolarizedTraitRef::Positive(trait_ref),
+        trait_ref,
         where_clauses: Vec::new(),
         associated_ty_values: Vec::new(),
+    };
+    let impl_datum = ImplDatum {
+        binders: make_binders(impl_datum_bound, 1),
         impl_type: chalk_rust_ir::ImplType::External,
+        polarity: chalk_rust_ir::Polarity::Positive,
     };
-    let impl_datum = ImplDatum { binders: make_binders(impl_datum_bound, 1) };
     Arc::new(impl_datum)
 }
 
@@ -713,12 +719,15 @@ fn closure_fn_trait_impl_datum(
     let impl_type = chalk_rust_ir::ImplType::External;
 
     let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
-        trait_ref: chalk_rust_ir::PolarizedTraitRef::Positive(trait_ref.to_chalk(db)),
+        trait_ref: trait_ref.to_chalk(db),
         where_clauses: Vec::new(),
         associated_ty_values: vec![output_ty_value],
+    };
+    let impl_datum = ImplDatum {
+        binders: make_binders(impl_datum_bound, num_args as usize + 1),
         impl_type,
+        polarity: chalk_rust_ir::Polarity::Positive,
     };
-    let impl_datum = ImplDatum { binders: make_binders(impl_datum_bound, num_args as usize + 1) };
     Some(Arc::new(impl_datum))
 }
 
diff --git a/crates/ra_hir/src/type_alias.rs b/crates/ra_hir/src/type_alias.rs
index 3b38c4740..674a46102 100644
--- a/crates/ra_hir/src/type_alias.rs
+++ b/crates/ra_hir/src/type_alias.rs
@@ -17,12 +17,14 @@ pub struct TypeAliasData {
     pub(crate) type_ref: Option<TypeRef>,
 }
 
-pub(crate) fn type_alias_data_query(
-    db: &(impl DefDatabase + AstDatabase),
-    typ: TypeAlias,
-) -> Arc<TypeAliasData> {
-    let node = typ.source(db).ast;
-    let name = node.name().map_or_else(Name::missing, |n| n.as_name());
-    let type_ref = node.type_ref().map(TypeRef::from_ast);
-    Arc::new(TypeAliasData { name, type_ref })
+impl TypeAliasData {
+    pub(crate) fn type_alias_data_query(
+        db: &(impl DefDatabase + AstDatabase),
+        typ: TypeAlias,
+    ) -> Arc<TypeAliasData> {
+        let node = typ.source(db).ast;
+        let name = node.name().map_or_else(Name::missing, |n| n.as_name());
+        let type_ref = node.type_ref().map(TypeRef::from_ast);
+        Arc::new(TypeAliasData { name, type_ref })
+    }
 }
diff --git a/crates/ra_hir/src/util.rs b/crates/ra_hir/src/util.rs
new file mode 100644
index 000000000..0095ee45d
--- /dev/null
+++ b/crates/ra_hir/src/util.rs
@@ -0,0 +1,12 @@
+//! Internal utility functions.
+
+use std::sync::Arc;
+
+/// Helper for mutating `Arc<[T]>` (i.e. `Arc::make_mut` for Arc slices).
+/// The underlying values are cloned if there are other strong references.
+pub(crate) fn make_mut_slice<T: Clone>(a: &mut Arc<[T]>) -> &mut [T] {
+    if Arc::get_mut(a).is_none() {
+        *a = a.iter().cloned().collect();
+    }
+    Arc::get_mut(a).unwrap()
+}
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide_api/Cargo.toml
index f919a2d61..f9bf0c686 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide_api/Cargo.toml
@@ -12,13 +12,14 @@ format-buf = "1.0.0"
 itertools = "0.8.0"
 join_to_string = "0.1.3"
 log = "0.4.5"
-relative-path = "0.4.0"
+relative-path = "1.0.0"
 rayon = "1.0.2"
 fst = { version = "0.3.1", default-features = false }
 rustc-hash = "1.0"
 unicase = "2.2.0"
 superslice = "1.0.0"
 rand = { version = "0.7.0", features = ["small_rng"] }
+once_cell = "1.2.0"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_text_edit = { path = "../ra_text_edit" }
diff --git a/crates/ra_ide_api/src/change.rs b/crates/ra_ide_api/src/change.rs
index 09913787b..050249c0e 100644
--- a/crates/ra_ide_api/src/change.rs
+++ b/crates/ra_ide_api/src/change.rs
@@ -4,7 +4,7 @@ use std::{fmt, sync::Arc, time};
 
 use ra_db::{
     salsa::{Database, Durability, SweepStrategy},
-    CrateGraph, CrateId, FileId, SourceDatabase, SourceRoot, SourceRootId,
+    CrateGraph, CrateId, FileId, SourceDatabase, SourceDatabaseExt, SourceRoot, SourceRootId,
 };
 use ra_prof::{memory_usage, profile, Bytes};
 use ra_syntax::SourceFile;
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index 28c8324d0..b4df6ee2a 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -119,27 +119,28 @@ mod tests {
             ",
         ),
         @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "foo",
-       ⋮        source_range: [187; 187),
-       ⋮        delete: [187; 187),
-       ⋮        insert: "foo()$0",
-       ⋮        kind: Method,
-       ⋮        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",
-       ⋮        ),
-       ⋮    },
-       ⋮]
+        [
+            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",
+                ),
+            },
+        ]
         "###
         );
     }
@@ -158,24 +159,25 @@ mod tests {
             ",
         ),
         @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "foo",
-       ⋮        source_range: [126; 126),
-       ⋮        delete: [126; 126),
-       ⋮        insert: "foo()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "fn foo(&self)",
-       ⋮    },
-       ⋮    CompletionItem {
-       ⋮        label: "the_field",
-       ⋮        source_range: [126; 126),
-       ⋮        delete: [126; 126),
-       ⋮        insert: "the_field",
-       ⋮        kind: Field,
-       ⋮        detail: "(u32, i32)",
-       ⋮    },
-       ⋮]
+        [
+            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)",
+            },
+        ]
         "###
         );
     }
@@ -210,16 +212,17 @@ mod tests {
             ",
         ),
         @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "the_method",
-       ⋮        source_range: [144; 144),
-       ⋮        delete: [144; 144),
-       ⋮        insert: "the_method()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "fn the_method(&self)",
-       ⋮    },
-       ⋮]
+        [
+            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)",
+            },
+        ]
         "###
         );
     }
@@ -238,16 +241,17 @@ mod tests {
             ",
             ),
             @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "the_method",
-       ⋮        source_range: [151; 151),
-       ⋮        delete: [151; 151),
-       ⋮        insert: "the_method()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "fn the_method(&self)",
-       ⋮    },
-       ⋮]
+        [
+            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)",
+            },
+        ]
         "###
         );
     }
@@ -266,16 +270,17 @@ mod tests {
             ",
             ),
             @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "the_method",
-       ⋮        source_range: [155; 155),
-       ⋮        delete: [155; 155),
-       ⋮        insert: "the_method()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "fn the_method(&self)",
-       ⋮    },
-       ⋮]
+        [
+            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)",
+            },
+        ]
         "###
         );
     }
@@ -317,16 +322,17 @@ mod tests {
             ",
         ),
         @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "the_method",
-       ⋮        source_range: [249; 249),
-       ⋮        delete: [249; 249),
-       ⋮        insert: "the_method()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "fn the_method(&self)",
-       ⋮    },
-       ⋮]
+        [
+            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)",
+            },
+        ]
         "###
         );
     }
@@ -386,16 +392,17 @@ mod tests {
             ",
         ),
         @r###"
-       ⋮[
-       ⋮    CompletionItem {
-       ⋮        label: "blah",
-       ⋮        source_range: [299; 300),
-       ⋮        delete: [299; 300),
-       ⋮        insert: "blah()$0",
-       ⋮        kind: Method,
-       ⋮        detail: "pub fn blah(&self)",
-       ⋮    },
-       ⋮]
+        [
+            CompletionItem {
+                label: "blah()",
+                source_range: [299; 300),
+                delete: [299; 300),
+                insert: "blah()$0",
+                kind: Method,
+                lookup: "blah",
+                detail: "pub fn blah(&self)",
+            },
+        ]
         "###
         );
     }
diff --git a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs b/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
index d808b2357..09f743c66 100644
--- a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
+++ b/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
@@ -56,6 +56,16 @@ mod tests {
             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 {
                     () => {}
                 }
@@ -68,13 +78,61 @@ mod tests {
             @r##"[
     CompletionItem {
         label: "vec!",
-        source_range: [46; 46),
-        delete: [46; 46),
+        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()",
+    },
+]
+        "###
+        );
+    }
 }
diff --git a/crates/ra_ide_api/src/completion/complete_path.rs b/crates/ra_ide_api/src/completion/complete_path.rs
index e01197fe4..23dece73c 100644
--- a/crates/ra_ide_api/src/completion/complete_path.rs
+++ b/crates/ra_ide_api/src/completion/complete_path.rs
@@ -375,19 +375,22 @@ mod tests {
                 fn foo() { let _ = S::<|> }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "m",
-        source_range: [100; 100),
-        delete: [100; 100),
-        insert: "m()$0",
-        kind: Function,
-        detail: "fn m()",
-        documentation: Documentation(
-            "An associated method",
-        ),
-    },
-]"###
+            @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",
+                ),
+            },
+        ]
+        "###
         );
     }
 
@@ -474,19 +477,22 @@ mod tests {
                 fn foo() { let _ = S::<|> }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "m",
-        source_range: [100; 100),
-        delete: [100; 100),
-        insert: "m()$0",
-        kind: Function,
-        detail: "fn m()",
-        documentation: Documentation(
-            "An associated method",
-        ),
-    },
-]"###
+            @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",
+                ),
+            },
+        ]
+        "###
         );
     }
 
@@ -507,19 +513,22 @@ mod tests {
                 fn foo() { let _ = U::<|> }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "m",
-        source_range: [101; 101),
-        delete: [101; 101),
-        insert: "m()$0",
-        kind: Function,
-        detail: "fn m()",
-        documentation: Documentation(
-            "An associated method",
-        ),
-    },
-]"###
+            @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",
+                ),
+            },
+        ]
+        "###
         );
     }
 
@@ -564,24 +573,28 @@ mod tests {
                 }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "bar",
-        source_range: [185; 185),
-        delete: [185; 185),
-        insert: "bar()$0",
-        kind: Function,
-        detail: "fn bar()",
-    },
-    CompletionItem {
-        label: "foo",
-        source_range: [185; 185),
-        delete: [185; 185),
-        insert: "foo()$0",
-        kind: Function,
-        detail: "fn foo()",
-    },
-]"###
+            @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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -600,24 +613,27 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn main()",
-    },
-]"###
+            @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()",
+            },
+        ]
+        "###
         );
     }
 }
diff --git a/crates/ra_ide_api/src/completion/complete_postfix.rs b/crates/ra_ide_api/src/completion/complete_postfix.rs
index 445a02676..555cecb73 100644
--- a/crates/ra_ide_api/src/completion/complete_postfix.rs
+++ b/crates/ra_ide_api/src/completion/complete_postfix.rs
@@ -8,7 +8,7 @@ use crate::{
     CompletionItem,
 };
 use hir::{Ty, TypeCtor};
-use ra_syntax::{ast::AstNode, TextRange};
+use ra_syntax::{ast::AstNode, TextRange, TextUnit};
 use ra_text_edit::TextEditBuilder;
 
 fn postfix_snippet(ctx: &CompletionContext, label: &str, detail: &str, snippet: &str) -> Builder {
@@ -42,7 +42,13 @@ fn is_bool_or_unknown(ty: Option<Ty>) -> bool {
 
 pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
     if let Some(dot_receiver) = &ctx.dot_receiver {
-        let receiver_text = dot_receiver.syntax().text().to_string();
+        let receiver_text = if ctx.dot_receiver_is_ambiguous_float_literal {
+            let text = dot_receiver.syntax().text();
+            let without_dot = ..text.len() - TextUnit::of_char('.');
+            text.slice(without_dot).to_string()
+        } else {
+            dot_receiver.syntax().text().to_string()
+        };
         let receiver_ty = ctx.analyzer.type_of(ctx.db, &dot_receiver);
         if is_bool_or_unknown(receiver_ty) {
             postfix_snippet(ctx, "if", "if expr {}", &format!("if {} {{$0}}", receiver_text))
@@ -209,4 +215,61 @@ mod tests {
 ]"###
         );
     }
+
+    #[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: "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",
+    },
+]"###
+        );
+    }
 }
diff --git a/crates/ra_ide_api/src/completion/complete_scope.rs b/crates/ra_ide_api/src/completion/complete_scope.rs
index 515a6285c..4e56de3f5 100644
--- a/crates/ra_ide_api/src/completion/complete_scope.rs
+++ b/crates/ra_ide_api/src/completion/complete_scope.rs
@@ -145,32 +145,35 @@ mod tests {
                 }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "quux",
-        source_range: [91; 91),
-        delete: [91; 91),
-        insert: "quux($0)",
-        kind: Function,
-        detail: "fn quux(x: i32)",
-    },
-    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",
-    },
-]"###
+            @r###"
+        [
+            CompletionItem {
+                label: "quux(…)",
+                source_range: [91; 91),
+                delete: [91; 91),
+                insert: "quux($0)",
+                kind: Function,
+                lookup: "quux",
+                detail: "fn quux(x: i32)",
+            },
+            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",
+            },
+        ]
+        "###
         );
     }
 
@@ -190,31 +193,34 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn quux()",
-    },
-]"###
+            @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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -230,23 +236,26 @@ mod tests {
                 }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "quux",
-        source_range: [95; 95),
-        delete: [95; 95),
-        insert: "quux()$0",
-        kind: Function,
-        detail: "fn quux()",
-    },
-    CompletionItem {
-        label: "x",
-        source_range: [95; 95),
-        delete: [95; 95),
-        insert: "x",
-        kind: Binding,
-    },
-]"###
+            @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,
+            },
+        ]
+        "###
         );
     }
 
@@ -260,23 +269,26 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "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>()",
+            },
+        ]
+        "###
         );
     }
 
@@ -290,22 +302,56 @@ mod tests {
                 }
                 "
             ),
-            @r###"[
-    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",
-        kind: Struct,
-    },
-]"###
+            @r###"
+        [
+            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",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[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,
+            },
+        ]
+        "###
         );
     }
 
@@ -321,30 +367,33 @@ mod tests {
                 }
                 "
         ),
-        @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,
-        detail: "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()",
+            },
+        ]
+        "###
             );
     }
 
@@ -384,23 +433,26 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -413,23 +465,26 @@ mod tests {
                 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,
-        detail: "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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -447,24 +502,27 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn foo()",
-    },
-]"###
+            @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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -509,30 +567,33 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn foo()",
-    },
-    CompletionItem {
-        label: "std",
-        source_range: [18; 18),
-        delete: [18; 18),
-        insert: "std",
-        kind: Module,
-    },
-]"#
+            @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,
+            },
+        ]
+        "###
         );
     }
 
@@ -569,54 +630,57 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn main()",
-    },
-]"##
+            @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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -635,24 +699,27 @@ mod tests {
                 }
                 "
             ),
-            @r##"[
-    CompletionItem {
-        label: "foo",
-        source_range: [49; 49),
-        delete: [49; 49),
-        insert: "foo()$0",
-        kind: Function,
-        detail: "fn foo()",
-    },
-    CompletionItem {
-        label: "foo!",
-        source_range: [49; 49),
-        delete: [49; 49),
-        insert: "foo!($0)",
-        kind: Macro,
-        detail: "macro_rules! 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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -671,24 +738,27 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "fn main()",
-    },
-]"##
+            @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()",
+            },
+        ]
+        "###
         );
     }
 
@@ -707,24 +777,27 @@ mod tests {
                 }
                 "
             ),
-            @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,
-        detail: "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()",
+            },
+        ]
+        "###
         );
     }
 }
diff --git a/crates/ra_ide_api/src/completion/completion_context.rs b/crates/ra_ide_api/src/completion/completion_context.rs
index e9ad06965..64cbc0f98 100644
--- a/crates/ra_ide_api/src/completion/completion_context.rs
+++ b/crates/ra_ide_api/src/completion/completion_context.rs
@@ -38,8 +38,11 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) is_new_item: bool,
     /// The receiver if this is a field or method access, i.e. writing something.<|>
     pub(super) dot_receiver: Option<ast::Expr>,
+    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,
+    pub(super) is_path_type: bool,
+    pub(super) has_type_args: bool,
 }
 
 impl<'a> CompletionContext<'a> {
@@ -76,6 +79,9 @@ impl<'a> CompletionContext<'a> {
             is_new_item: false,
             dot_receiver: None,
             is_call: false,
+            is_path_type: false,
+            has_type_args: false,
+            dot_receiver_is_ambiguous_float_literal: false,
         };
         ctx.fill(&original_parse, position.offset);
         Some(ctx)
@@ -176,6 +182,9 @@ impl<'a> CompletionContext<'a> {
                 .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::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();
+
             if let Some(mut path) = hir::Path::from_ast(path.clone()) {
                 if !path.is_ident() {
                     path.segments.pop().unwrap();
@@ -228,6 +237,16 @@ impl<'a> CompletionContext<'a> {
                 .expr()
                 .map(|e| e.syntax().text_range())
                 .and_then(|r| find_node_with_range(original_file.syntax(), r));
+            self.dot_receiver_is_ambiguous_float_literal = if let Some(ast::Expr::Literal(l)) =
+                &self.dot_receiver
+            {
+                match l.kind() {
+                    ast::LiteralKind::FloatNumber { suffix: _ } => l.token().text().ends_with('.'),
+                    _ => false,
+                }
+            } else {
+                false
+            }
         }
         if let Some(method_call_expr) = ast::MethodCallExpr::cast(parent) {
             // As above
diff --git a/crates/ra_ide_api/src/completion/completion_item.rs b/crates/ra_ide_api/src/completion/completion_item.rs
index b1f0390ec..3e6933bc1 100644
--- a/crates/ra_ide_api/src/completion/completion_item.rs
+++ b/crates/ra_ide_api/src/completion/completion_item.rs
@@ -216,6 +216,10 @@ impl Builder {
         self.lookup = Some(lookup.into());
         self
     }
+    pub(crate) fn label(mut self, label: impl Into<String>) -> Builder {
+        self.label = label.into();
+        self
+    }
     pub(crate) fn insert_text(mut self, insert_text: impl Into<String>) -> Builder {
         self.insert_text = Some(insert_text.into());
         self
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide_api/src/completion/presentation.rs
index 48028a2f9..aed4ce6d4 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide_api/src/completion/presentation.rs
@@ -1,12 +1,12 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{Docs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
+use hir::{db::HirDatabase, Docs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
 use test_utils::tested_by;
 
 use crate::completion::{
-    CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
+    db, CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
 };
 
 use crate::display::{const_label, function_label, macro_label, type_label};
@@ -44,54 +44,56 @@ impl Completions {
     ) {
         use hir::ModuleDef::*;
 
-        let mut completion_kind = CompletionKind::Reference;
-        let (kind, docs) = match resolution {
-            ScopeDef::ModuleDef(Module(it)) => (CompletionItemKind::Module, it.docs(ctx.db)),
+        let completion_kind = match resolution {
+            ScopeDef::ModuleDef(BuiltinType(..)) => CompletionKind::BuiltinType,
+            _ => CompletionKind::Reference,
+        };
+
+        let kind = match resolution {
+            ScopeDef::ModuleDef(Module(..)) => CompletionItemKind::Module,
             ScopeDef::ModuleDef(Function(func)) => {
                 return self.add_function_with_name(ctx, Some(local_name), *func);
             }
-            ScopeDef::ModuleDef(Adt(hir::Adt::Struct(it))) => {
-                (CompletionItemKind::Struct, it.docs(ctx.db))
-            }
-            ScopeDef::ModuleDef(Adt(hir::Adt::Union(it))) => {
-                (CompletionItemKind::Struct, it.docs(ctx.db))
-            }
-            ScopeDef::ModuleDef(Adt(hir::Adt::Enum(it))) => {
-                (CompletionItemKind::Enum, it.docs(ctx.db))
-            }
-            ScopeDef::ModuleDef(EnumVariant(it)) => {
-                (CompletionItemKind::EnumVariant, it.docs(ctx.db))
-            }
-            ScopeDef::ModuleDef(Const(it)) => (CompletionItemKind::Const, it.docs(ctx.db)),
-            ScopeDef::ModuleDef(Static(it)) => (CompletionItemKind::Static, it.docs(ctx.db)),
-            ScopeDef::ModuleDef(Trait(it)) => (CompletionItemKind::Trait, it.docs(ctx.db)),
-            ScopeDef::ModuleDef(TypeAlias(it)) => (CompletionItemKind::TypeAlias, it.docs(ctx.db)),
-            ScopeDef::ModuleDef(BuiltinType(..)) => {
-                completion_kind = CompletionKind::BuiltinType;
-                (CompletionItemKind::BuiltinType, None)
-            }
-            ScopeDef::GenericParam(..) => (CompletionItemKind::TypeParam, None),
-            ScopeDef::LocalBinding(..) => (CompletionItemKind::Binding, None),
-            ScopeDef::SelfType(..) => (
-                CompletionItemKind::TypeParam, // (does this need its own kind?)
-                None,
-            ),
+            ScopeDef::ModuleDef(Adt(hir::Adt::Struct(_))) => CompletionItemKind::Struct,
+            // FIXME: add CompletionItemKind::Union
+            ScopeDef::ModuleDef(Adt(hir::Adt::Union(_))) => CompletionItemKind::Struct,
+            ScopeDef::ModuleDef(Adt(hir::Adt::Enum(_))) => CompletionItemKind::Enum,
+
+            ScopeDef::ModuleDef(EnumVariant(..)) => CompletionItemKind::EnumVariant,
+            ScopeDef::ModuleDef(Const(..)) => CompletionItemKind::Const,
+            ScopeDef::ModuleDef(Static(..)) => CompletionItemKind::Static,
+            ScopeDef::ModuleDef(Trait(..)) => CompletionItemKind::Trait,
+            ScopeDef::ModuleDef(TypeAlias(..)) => CompletionItemKind::TypeAlias,
+            ScopeDef::ModuleDef(BuiltinType(..)) => CompletionItemKind::BuiltinType,
+            ScopeDef::GenericParam(..) => CompletionItemKind::TypeParam,
+            ScopeDef::LocalBinding(..) => CompletionItemKind::Binding,
+            // (does this need its own kind?)
+            ScopeDef::AdtSelfType(..) | ScopeDef::ImplSelfType(..) => CompletionItemKind::TypeParam,
             ScopeDef::MacroDef(mac) => {
-                self.add_macro(ctx, Some(local_name), *mac);
-                return;
+                return self.add_macro(ctx, Some(local_name), *mac);
             }
             ScopeDef::Unknown => {
-                self.add(CompletionItem::new(
+                return self.add(CompletionItem::new(
                     CompletionKind::Reference,
                     ctx.source_range(),
                     local_name,
                 ));
-                return;
             }
         };
 
+        let docs = match resolution {
+            ScopeDef::ModuleDef(Module(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Adt(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(EnumVariant(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Const(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Static(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(Trait(it)) => it.docs(ctx.db),
+            ScopeDef::ModuleDef(TypeAlias(it)) => it.docs(ctx.db),
+            _ => None,
+        };
+
         let mut completion_item =
-            CompletionItem::new(completion_kind, ctx.source_range(), local_name);
+            CompletionItem::new(completion_kind, ctx.source_range(), local_name.clone());
         if let ScopeDef::LocalBinding(pat_id) = resolution {
             let ty = ctx
                 .analyzer
@@ -100,6 +102,28 @@ impl Completions {
                 .map(|t| t.display(ctx.db).to_string());
             completion_item = completion_item.set_detail(ty);
         };
+
+        // If not an import, add parenthesis automatically.
+        if ctx.is_path_type
+            && !ctx.has_type_args
+            && ctx.db.feature_flags.get("completion.insertion.add-call-parenthesis")
+        {
+            let generic_def: Option<hir::GenericDef> = match resolution {
+                ScopeDef::ModuleDef(Adt(it)) => Some((*it).into()),
+                ScopeDef::ModuleDef(TypeAlias(it)) => Some((*it).into()),
+                _ => None,
+            };
+            if let Some(def) = generic_def {
+                if has_non_default_type_params(def, ctx.db) {
+                    tested_by!(inserts_angle_brackets_for_generics);
+                    completion_item = completion_item
+                        .lookup_by(local_name.clone())
+                        .label(format!("{}<…>", local_name))
+                        .insert_snippet(format!("{}<$0>", local_name));
+                }
+            }
+        }
+
         completion_item.kind(kind).set_documentation(docs).add_to(self)
     }
 
@@ -107,6 +131,33 @@ impl Completions {
         self.add_function_with_name(ctx, None, func)
     }
 
+    fn guess_macro_braces(&self, macro_name: &str, docs: &str) -> &'static str {
+        let mut votes = [0, 0, 0];
+        for (idx, s) in docs.match_indices(&macro_name) {
+            let (before, after) = (&docs[..idx], &docs[idx + s.len()..]);
+            // Ensure to match the full word
+            if after.starts_with("!")
+                && before
+                    .chars()
+                    .rev()
+                    .next()
+                    .map_or(true, |c| c != '_' && !c.is_ascii_alphanumeric())
+            {
+                // It may have spaces before the braces like `foo! {}`
+                match after[1..].chars().find(|&c| !c.is_whitespace()) {
+                    Some('{') => votes[0] += 1,
+                    Some('[') => votes[1] += 1,
+                    Some('(') => votes[2] += 1,
+                    _ => {}
+                }
+            }
+        }
+
+        // Insert a space before `{}`.
+        // We prefer the last one when some votes equal.
+        *votes.iter().zip(&[" {$0}", "[$0]", "($0)"]).max_by_key(|&(&vote, _)| vote).unwrap().1
+    }
+
     pub(crate) fn add_macro(
         &mut self,
         ctx: &CompletionContext,
@@ -117,10 +168,9 @@ impl Completions {
         if let Some(name) = name {
             let detail = macro_label(&ast_node);
 
-            let macro_braces_to_insert = match name.as_str() {
-                "vec" => "[$0]",
-                _ => "($0)",
-            };
+            let docs = macro_.docs(ctx.db);
+            let macro_braces_to_insert =
+                self.guess_macro_braces(&name, docs.as_ref().map_or("", |s| s.as_str()));
             let macro_declaration = name + "!";
 
             let builder = CompletionItem::new(
@@ -129,7 +179,7 @@ impl Completions {
                 &macro_declaration,
             )
             .kind(CompletionItemKind::Macro)
-            .set_documentation(macro_.docs(ctx.db))
+            .set_documentation(docs)
             .detail(detail)
             .insert_snippet(macro_declaration + macro_braces_to_insert);
 
@@ -148,28 +198,31 @@ impl Completions {
         let ast_node = func.source(ctx.db).ast;
         let detail = function_label(&ast_node);
 
-        let mut builder = CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name)
-            .kind(if data.has_self_param() {
-                CompletionItemKind::Method
-            } else {
-                CompletionItemKind::Function
-            })
-            .set_documentation(func.docs(ctx.db))
-            .detail(detail);
-        // If not an import, add parenthesis automatically.
+        let mut builder =
+            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.clone())
+                .kind(if data.has_self_param() {
+                    CompletionItemKind::Method
+                } else {
+                    CompletionItemKind::Function
+                })
+                .set_documentation(func.docs(ctx.db))
+                .detail(detail);
+
+        // Add `<>` for generic types
         if ctx.use_item_syntax.is_none()
             && !ctx.is_call
             && ctx.db.feature_flags.get("completion.insertion.add-call-parenthesis")
         {
             tested_by!(inserts_parens_for_function_calls);
-            let snippet =
+            let (snippet, label) =
                 if data.params().is_empty() || data.has_self_param() && data.params().len() == 1 {
-                    format!("{}()$0", data.name())
+                    (format!("{}()$0", data.name()), format!("{}()", name))
                 } else {
-                    format!("{}($0)", data.name())
+                    (format!("{}($0)", data.name()), format!("{}(…)", name))
                 };
-            builder = builder.insert_snippet(snippet);
+            builder = builder.lookup_by(name.clone()).label(label).insert_snippet(snippet);
         }
+
         self.add(builder)
     }
 
@@ -213,7 +266,6 @@ impl Completions {
             .separator(", ")
             .surround_with("(", ")")
             .to_string();
-
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.to_string())
             .kind(CompletionItemKind::EnumVariant)
             .set_documentation(variant.docs(ctx.db))
@@ -222,6 +274,11 @@ impl Completions {
     }
 }
 
+fn has_non_default_type_params(def: hir::GenericDef, db: &db::RootDatabase) -> bool {
+    let subst = db.generic_defaults(def);
+    subst.iter().any(|ty| ty == &Ty::Unknown)
+}
+
 #[cfg(test)]
 mod tests {
     use crate::completion::{do_completion, CompletionItem, CompletionKind};
@@ -242,24 +299,28 @@ mod tests {
                 fn main() { no_<|> }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "main",
-        source_range: [61; 64),
-        delete: [61; 64),
-        insert: "main()$0",
-        kind: Function,
-        detail: "fn main()",
-    },
-    CompletionItem {
-        label: "no_args",
-        source_range: [61; 64),
-        delete: [61; 64),
-        insert: "no_args()$0",
-        kind: Function,
-        detail: "fn no_args()",
-    },
-]"###
+            @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(
@@ -268,24 +329,28 @@ mod tests {
                 fn main() { with_<|> }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "main",
-        source_range: [80; 85),
-        delete: [80; 85),
-        insert: "main()$0",
-        kind: Function,
-        detail: "fn main()",
-    },
-    CompletionItem {
-        label: "with_args",
-        source_range: [80; 85),
-        delete: [80; 85),
-        insert: "with_args($0)",
-        kind: Function,
-        detail: "fn with_args(x: i32, y: String)",
-    },
-]"###
+            @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($0)",
+                kind: Function,
+                lookup: "with_args",
+                detail: "fn with_args(x: i32, y: String)",
+            },
+        ]
+        "###
         );
         assert_debug_snapshot!(
             do_reference_completion(
@@ -299,16 +364,19 @@ mod tests {
                 }
                 "
             ),
-            @r###"[
-    CompletionItem {
-        label: "foo",
-        source_range: [163; 164),
-        delete: [163; 164),
-        insert: "foo()$0",
-        kind: Method,
-        detail: "fn foo(&self)",
-    },
-]"###
+            @r###"
+        [
+            CompletionItem {
+                label: "foo()",
+                source_range: [163; 164),
+                delete: [163; 164),
+                insert: "foo()$0",
+                kind: Method,
+                lookup: "foo",
+                detail: "fn foo(&self)",
+            },
+        ]
+        "###
         );
     }
 
@@ -389,4 +457,123 @@ mod tests {
 ]"#
         );
     }
+
+    #[test]
+    fn inserts_angle_brackets_for_generics() {
+        covers!(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($0)",
+                kind: Function,
+                lookup: "foo",
+                detail: "fn foo(xs: Ve)",
+            },
+        ]
+        "###
+        );
+        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($0)",
+                kind: Function,
+                lookup: "foo",
+                detail: "fn foo(xs: Ve)",
+            },
+        ]
+        "###
+        );
+        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($0)",
+                kind: Function,
+                lookup: "foo",
+                detail: "fn foo(xs: Ve)",
+            },
+        ]
+        "###
+        );
+        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($0)",
+                kind: Function,
+                lookup: "foo",
+                detail: "fn foo(xs: Ve<i128>)",
+            },
+        ]
+        "###
+        );
+    }
 }
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index ea0714add..9146b647a 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -4,8 +4,10 @@ use std::sync::Arc;
 
 use ra_db::{
     salsa::{self, Database, Durability},
-    Canceled, CheckCanceled, CrateId, FileId, SourceDatabase, SourceRootId,
+    Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase,
+    SourceDatabaseExt, SourceRootId,
 };
+use relative_path::RelativePath;
 use rustc_hash::FxHashMap;
 
 use crate::{
@@ -15,6 +17,7 @@ use crate::{
 
 #[salsa::database(
     ra_db::SourceDatabaseStorage,
+    ra_db::SourceDatabaseExtStorage,
     LineIndexDatabaseStorage,
     symbol_index::SymbolsDatabaseStorage,
     hir::db::InternDatabaseStorage,
@@ -31,6 +34,22 @@ pub(crate) struct RootDatabase {
     pub(crate) last_gc_check: crate::wasm_shims::Instant,
 }
 
+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 relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+        FileLoaderDelegate(self).relevant_crates(file_id)
+    }
+}
+
 impl hir::debug::HirDebugHelper for RootDatabase {
     fn crate_name(&self, krate: CrateId) -> Option<String> {
         self.debug_data.crate_names.get(&krate).cloned()
@@ -39,7 +58,7 @@ impl hir::debug::HirDebugHelper for RootDatabase {
         let source_root_id = self.file_source_root(file_id);
         let source_root_path = self.debug_data.root_paths.get(&source_root_id)?;
         let file_path = self.file_relative_path(file_id);
-        Some(format!("{}/{}", source_root_path, file_path.display()))
+        Some(format!("{}/{}", source_root_path, file_path))
     }
 }
 
@@ -104,7 +123,7 @@ pub(crate) trait LineIndexDatabase: ra_db::SourceDatabase + CheckCanceled {
     fn line_index(&self, file_id: FileId) -> Arc<LineIndex>;
 }
 
-fn line_index(db: &impl ra_db::SourceDatabase, file_id: FileId) -> Arc<LineIndex> {
+fn line_index(db: &impl LineIndexDatabase, file_id: FileId) -> Arc<LineIndex> {
     let text = db.file_text(file_id);
     Arc::new(LineIndex::new(&*text))
 }
diff --git a/crates/ra_ide_api/src/diagnostics.rs b/crates/ra_ide_api/src/diagnostics.rs
index 0435188c8..8743a3a79 100644
--- a/crates/ra_ide_api/src/diagnostics.rs
+++ b/crates/ra_ide_api/src/diagnostics.rs
@@ -4,7 +4,7 @@ use std::cell::RefCell;
 
 use hir::diagnostics::{AstDiagnostic, Diagnostic as _, DiagnosticSink};
 use itertools::Itertools;
-use ra_db::SourceDatabase;
+use ra_db::{SourceDatabase, SourceDatabaseExt};
 use ra_prof::profile;
 use ra_syntax::{
     algo,
@@ -12,6 +12,7 @@ use ra_syntax::{
     Location, SyntaxNode, TextRange, T,
 };
 use ra_text_edit::{TextEdit, TextEditBuilder};
+use relative_path::RelativePath;
 
 use crate::{db::RootDatabase, Diagnostic, FileId, FileSystemEdit, SourceChange, SourceFileEdit};
 
@@ -47,8 +48,14 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         })
     })
     .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
-        let source_root = db.file_source_root(d.source().file_id.original_file(db));
-        let create_file = FileSystemEdit::CreateFile { source_root, path: d.candidate.clone() };
+        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 create_file = FileSystemEdit::CreateFile { source_root, path };
         let fix = SourceChange::file_system_edit("create module", create_file);
         res.borrow_mut().push(Diagnostic {
             range: d.highlight_range(),
diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide_api/src/display/navigation_target.rs
index d0b1a8a2a..5cb67fb95 100644
--- a/crates/ra_ide_api/src/display/navigation_target.rs
+++ b/crates/ra_ide_api/src/display/navigation_target.rs
@@ -119,7 +119,7 @@ impl NavigationTarget {
 
     pub(crate) fn from_module(db: &RootDatabase, module: hir::Module) -> NavigationTarget {
         let src = module.definition_source(db);
-        let file_id = src.file_id.as_original_file();
+        let file_id = src.file_id.original_file(db);
         let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
         match src.ast {
             ModuleSource::SourceFile(node) => {
@@ -139,7 +139,7 @@ impl NavigationTarget {
     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 file_id = src.file_id.as_original_file();
+            let file_id = src.file_id.original_file(db);
             return NavigationTarget::from_syntax(
                 file_id,
                 name,
@@ -213,7 +213,7 @@ impl NavigationTarget {
     ) -> NavigationTarget {
         let src = impl_block.source(db);
         NavigationTarget::from_syntax(
-            src.file_id.as_original_file(),
+            src.file_id.original_file(db),
             "impl".into(),
             None,
             src.ast.syntax(),
diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide_api/src/extend_selection.rs
index 33fefb541..602757e92 100644
--- a/crates/ra_ide_api/src/extend_selection.rs
+++ b/crates/ra_ide_api/src/extend_selection.rs
@@ -32,6 +32,7 @@ fn try_extend_selection(root: &SyntaxNode, range: TextRange) -> Option<TextRange
         PARAM_LIST,
         ARG_LIST,
         ARRAY_EXPR,
+        TUPLE_EXPR,
     ];
 
     if range.is_empty() {
@@ -245,6 +246,8 @@ mod tests {
         do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|>];"#, &["33", ", 33"]);
         do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", ", 33"]);
 
+        do_check(r#"fn main() { (1, 2<|>) }"#, &["2", ", 2", "(1, 2)"]);
+
         do_check(
             r#"
 const FOO: [usize; 2] = [
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 41a88314f..1f3fa6c57 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -10,7 +10,7 @@ use ra_syntax::{
 use crate::{
     db::RootDatabase,
     display::ShortLabel,
-    name_ref_kind::{classify_name_ref, NameRefKind::*},
+    references::{classify_name_ref, NameKind::*},
     FilePosition, NavigationTarget, RangeInfo,
 };
 
@@ -54,13 +54,11 @@ pub(crate) fn reference_definition(
 ) -> ReferenceResult {
     use self::ReferenceResult::*;
 
-    let analyzer = hir::SourceAnalyzer::new(db, file_id, name_ref.syntax(), None);
-
-    match classify_name_ref(db, &analyzer, name_ref) {
+    let name_kind = classify_name_ref(db, file_id, &name_ref).map(|d| d.kind);
+    match name_kind {
         Some(Macro(mac)) => return Exact(NavigationTarget::from_macro_def(db, mac)),
-        Some(FieldAccess(field)) => return Exact(NavigationTarget::from_field(db, field)),
+        Some(Field(field)) => return Exact(NavigationTarget::from_field(db, field)),
         Some(AssocItem(assoc)) => return Exact(NavigationTarget::from_assoc_item(db, assoc)),
-        Some(Method(func)) => return Exact(NavigationTarget::from_def_source(db, func)),
         Some(Def(def)) => match NavigationTarget::from_def(db, def) {
             Some(nav) => return Exact(nav),
             None => return Approximate(vec![]),
@@ -70,7 +68,7 @@ pub(crate) fn reference_definition(
                 return Exact(NavigationTarget::from_adt_def(db, def_id));
             }
         }
-        Some(Pat(pat)) => return Exact(NavigationTarget::from_pat(db, file_id, pat)),
+        Some(Pat((_, pat))) => return Exact(NavigationTarget::from_pat(db, file_id, pat)),
         Some(SelfParam(par)) => return Exact(NavigationTarget::from_self_param(file_id, par)),
         Some(GenericParam(_)) => {
             // FIXME: go to the generic param def
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 24b161c5c..ba328efa1 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -14,7 +14,7 @@ use crate::{
         description_from_symbol, docs_from_symbol, macro_label, rust_code_markup,
         rust_code_markup_with_doc, ShortLabel,
     },
-    name_ref_kind::{classify_name_ref, NameRefKind::*},
+    references::{classify_name_ref, NameKind::*},
     FilePosition, FileRange, RangeInfo,
 };
 
@@ -99,17 +99,14 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
 
     let mut range = None;
     if let Some(name_ref) = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset) {
-        let analyzer = hir::SourceAnalyzer::new(db, position.file_id, name_ref.syntax(), None);
-
         let mut no_fallback = false;
-
-        match classify_name_ref(db, &analyzer, &name_ref) {
-            Some(Method(it)) => res.extend(from_def_source(db, it)),
+        let name_kind = classify_name_ref(db, position.file_id, &name_ref).map(|d| d.kind);
+        match name_kind {
             Some(Macro(it)) => {
                 let src = it.source(db);
                 res.extend(hover_text(src.ast.doc_comment_text(), Some(macro_label(&src.ast))));
             }
-            Some(FieldAccess(it)) => {
+            Some(Field(it)) => {
                 let src = it.source(db);
                 if let hir::FieldSource::Named(it) = src.ast {
                     res.extend(hover_text(it.doc_comment_text(), it.short_label()));
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 24f1b91f6..19669a7f0 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -19,7 +19,6 @@ mod feature_flags;
 mod status;
 mod completion;
 mod runnables;
-mod name_ref_kind;
 mod goto_definition;
 mod goto_type_definition;
 mod extend_selection;
@@ -52,7 +51,7 @@ use std::sync::Arc;
 use ra_cfg::CfgOptions;
 use ra_db::{
     salsa::{self, ParallelDatabase},
-    CheckCanceled, SourceDatabase,
+    CheckCanceled, FileLoader, SourceDatabase,
 };