187 files changed, 13463 insertions, 9824 deletions

diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index 0ea84d548..993aebc47 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -1,5 +1,5 @@
 //! This module defines `AssistCtx` -- the API surface that is exposed to assists.
-use hir::{db::HirDatabase, SourceAnalyzer};
+use hir::{db::HirDatabase, InFile, SourceAnalyzer};
 use ra_db::FileRange;
 use ra_fmt::{leading_indent, reindent};
 use ra_syntax::{
@@ -117,7 +117,7 @@ impl<'a, DB: HirDatabase> AssistCtx<'a, DB> {
         node: &SyntaxNode,
         offset: Option<TextUnit>,
     ) -> SourceAnalyzer {
-        SourceAnalyzer::new(self.db, hir::Source::new(self.frange.file_id.into(), node), offset)
+        SourceAnalyzer::new(self.db, InFile::new(self.frange.file_id.into(), node), offset)
     }
 
     pub(crate) fn covering_node_for_range(&self, range: TextRange) -> SyntaxElement {
diff --git a/crates/ra_assists/src/assists/add_custom_impl.rs b/crates/ra_assists/src/assists/add_custom_impl.rs
new file mode 100644
index 000000000..037306fd6
--- /dev/null
+++ b/crates/ra_assists/src/assists/add_custom_impl.rs
@@ -0,0 +1,206 @@
+//! FIXME: write short doc here
+
+use crate::{Assist, AssistCtx, AssistId};
+use hir::db::HirDatabase;
+use join_to_string::join;
+use ra_syntax::{
+    ast::{self, AstNode},
+    Direction, SmolStr,
+    SyntaxKind::{IDENT, WHITESPACE},
+    TextRange, TextUnit,
+};
+
+const DERIVE_TRAIT: &'static str = "derive";
+
+// Assist: add_custom_impl
+//
+// Adds impl block for derived trait.
+//
+// ```
+// #[derive(Deb<|>ug, Display)]
+// struct S;
+// ```
+// ->
+// ```
+// #[derive(Display)]
+// struct S;
+//
+// impl Debug for S {
+//
+// }
+// ```
+pub(crate) fn add_custom_impl(ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let input = ctx.find_node_at_offset::<ast::AttrInput>()?;
+    let attr = input.syntax().parent().and_then(ast::Attr::cast)?;
+
+    let attr_name = attr
+        .syntax()
+        .descendants_with_tokens()
+        .filter(|t| t.kind() == IDENT)
+        .find_map(|i| i.into_token())
+        .filter(|t| *t.text() == DERIVE_TRAIT)?
+        .text()
+        .clone();
+
+    let trait_token =
+        ctx.token_at_offset().filter(|t| t.kind() == IDENT && *t.text() != attr_name).next()?;
+
+    let annotated = attr.syntax().siblings(Direction::Next).find_map(|s| ast::Name::cast(s))?;
+    let annotated_name = annotated.syntax().text().to_string();
+    let start_offset = annotated.syntax().parent()?.text_range().end();
+
+    ctx.add_assist(AssistId("add_custom_impl"), "add custom impl", |edit| {
+        edit.target(attr.syntax().text_range());
+
+        let new_attr_input = input
+            .syntax()
+            .descendants_with_tokens()
+            .filter(|t| t.kind() == IDENT)
+            .filter_map(|t| t.into_token().map(|t| t.text().clone()))
+            .filter(|t| t != trait_token.text())
+            .collect::<Vec<SmolStr>>();
+        let has_more_derives = new_attr_input.len() > 0;
+        let new_attr_input =
+            join(new_attr_input.iter()).separator(", ").surround_with("(", ")").to_string();
+        let new_attr_input_len = new_attr_input.len();
+
+        let mut buf = String::new();
+        buf.push_str("\n\nimpl ");
+        buf.push_str(trait_token.text().as_str());
+        buf.push_str(" for ");
+        buf.push_str(annotated_name.as_str());
+        buf.push_str(" {\n");
+
+        let cursor_delta = if has_more_derives {
+            edit.replace(input.syntax().text_range(), new_attr_input);
+            input.syntax().text_range().len() - TextUnit::from_usize(new_attr_input_len)
+        } else {
+            let attr_range = attr.syntax().text_range();
+            edit.delete(attr_range);
+
+            let line_break_range = attr
+                .syntax()
+                .next_sibling_or_token()
+                .filter(|t| t.kind() == WHITESPACE)
+                .map(|t| t.text_range())
+                .unwrap_or(TextRange::from_to(TextUnit::from(0), TextUnit::from(0)));
+            edit.delete(line_break_range);
+
+            attr_range.len() + line_break_range.len()
+        };
+
+        edit.set_cursor(start_offset + TextUnit::of_str(&buf) - cursor_delta);
+        buf.push_str("\n}");
+        edit.insert(start_offset, buf);
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+
+    #[test]
+    fn add_custom_impl_for_unique_input() {
+        check_assist(
+            add_custom_impl,
+            "
+#[derive(Debu<|>g)]
+struct Foo {
+    bar: String,
+}
+            ",
+            "
+struct Foo {
+    bar: String,
+}
+
+impl Debug for Foo {
+<|>
+}
+            ",
+        )
+    }
+
+    #[test]
+    fn add_custom_impl_for_with_visibility_modifier() {
+        check_assist(
+            add_custom_impl,
+            "
+#[derive(Debug<|>)]
+pub struct Foo {
+    bar: String,
+}
+            ",
+            "
+pub struct Foo {
+    bar: String,
+}
+
+impl Debug for Foo {
+<|>
+}
+            ",
+        )
+    }
+
+    #[test]
+    fn add_custom_impl_when_multiple_inputs() {
+        check_assist(
+            add_custom_impl,
+            "
+#[derive(Display, Debug<|>, Serialize)]
+struct Foo {}
+            ",
+            "
+#[derive(Display, Serialize)]
+struct Foo {}
+
+impl Debug for Foo {
+<|>
+}
+            ",
+        )
+    }
+
+    #[test]
+    fn test_ignore_derive_macro_without_input() {
+        check_assist_not_applicable(
+            add_custom_impl,
+            "
+#[derive(<|>)]
+struct Foo {}
+            ",
+        )
+    }
+
+    #[test]
+    fn test_ignore_if_cursor_on_param() {
+        check_assist_not_applicable(
+            add_custom_impl,
+            "
+#[derive<|>(Debug)]
+struct Foo {}
+            ",
+        );
+
+        check_assist_not_applicable(
+            add_custom_impl,
+            "
+#[derive(Debug)<|>]
+struct Foo {}
+            ",
+        )
+    }
+
+    #[test]
+    fn test_ignore_if_not_derive() {
+        check_assist_not_applicable(
+            add_custom_impl,
+            "
+#[allow(non_camel_<|>case_types)]
+struct Foo {}
+            ",
+        )
+    }
+}
diff --git a/crates/ra_assists/src/assists/add_import.rs b/crates/ra_assists/src/assists/add_import.rs
index 363ade016..b8752cbad 100644
--- a/crates/ra_assists/src/assists/add_import.rs
+++ b/crates/ra_assists/src/assists/add_import.rs
@@ -578,17 +578,21 @@ fn apply_auto_import(
 
 fn collect_hir_path_segments(path: &hir::Path) -> Option<Vec<SmolStr>> {
     let mut ps = Vec::<SmolStr>::with_capacity(10);
-    match path.kind {
+    match path.kind() {
         hir::PathKind::Abs => ps.push("".into()),
         hir::PathKind::Crate => ps.push("crate".into()),
         hir::PathKind::Plain => {}
-        hir::PathKind::Self_ => ps.push("self".into()),
-        hir::PathKind::Super => ps.push("super".into()),
-        hir::PathKind::Type(_) | hir::PathKind::DollarCrate(_) => return None,
-    }
-    for s in path.segments.iter() {
-        ps.push(s.name.to_string().into());
+        hir::PathKind::Super(0) => ps.push("self".into()),
+        hir::PathKind::Super(lvl) => {
+            let mut chain = "super".to_string();
+            for _ in 0..*lvl {
+                chain += "::super";
+            }
+            ps.push(chain.into());
+        }
+        hir::PathKind::DollarCrate(_) => return None,
     }
+    ps.extend(path.segments().iter().map(|it| it.name.to_string().into()));
     Some(ps)
 }
 
diff --git a/crates/ra_assists/src/assists/add_new.rs b/crates/ra_assists/src/assists/add_new.rs
index 8f68bd5fb..b2f946fac 100644
--- a/crates/ra_assists/src/assists/add_new.rs
+++ b/crates/ra_assists/src/assists/add_new.rs
@@ -1,5 +1,5 @@
 use format_buf::format;
-use hir::{db::HirDatabase, FromSource};
+use hir::{db::HirDatabase, FromSource, InFile};
 use join_to_string::join;
 use ra_syntax::{
     ast::{
@@ -56,42 +56,39 @@ pub(crate) fn add_new(ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
         let vis = vis.as_ref().map(String::as_str).unwrap_or("");
         write!(&mut buf, "    {}fn new(", vis).unwrap();
 
-        join(field_list.fields().map(|f| {
-            format!(
-                "{}: {}",
-                f.name().unwrap().syntax().text(),
-                f.ascribed_type().unwrap().syntax().text()
-            )
+        join(field_list.fields().filter_map(|f| {
+            Some(format!("{}: {}", f.name()?.syntax().text(), f.ascribed_type()?.syntax().text()))
         }))
         .separator(", ")
         .to_buf(&mut buf);
 
         buf.push_str(") -> Self { Self {");
 
-        join(field_list.fields().map(|f| f.name().unwrap().syntax().text()))
+        join(field_list.fields().filter_map(|f| Some(f.name()?.syntax().text())))
             .separator(", ")
             .surround_with(" ", " ")
             .to_buf(&mut buf);
 
         buf.push_str("} }");
 
-        let (start_offset, end_offset) = if let Some(impl_block) = impl_block {
-            buf.push('\n');
-            let start = impl_block
-                .syntax()
-                .descendants_with_tokens()
-                .find(|t| t.kind() == T!['{'])
-                .unwrap()
-                .text_range()
-                .end();
-
-            (start, TextUnit::from_usize(1))
-        } else {
-            buf = generate_impl_text(&strukt, &buf);
-            let start = strukt.syntax().text_range().end();
-
-            (start, TextUnit::from_usize(3))
-        };
+        let (start_offset, end_offset) = impl_block
+            .and_then(|impl_block| {
+                buf.push('\n');
+                let start = impl_block
+                    .syntax()
+                    .descendants_with_tokens()
+                    .find(|t| t.kind() == T!['{'])?
+                    .text_range()
+                    .end();
+
+                Some((start, TextUnit::from_usize(1)))
+            })
+            .unwrap_or_else(|| {
+                buf = generate_impl_text(&strukt, &buf);
+                let start = strukt.syntax().text_range().end();
+
+                (start, TextUnit::from_usize(3))
+            });
 
         edit.set_cursor(start_offset + TextUnit::of_str(&buf) - end_offset);
         edit.insert(start_offset, buf);
@@ -141,44 +138,41 @@ fn find_struct_impl(
     })?;
 
     let struct_ty = {
-        let src = hir::Source { file_id: ctx.frange.file_id.into(), value: strukt.clone() };
-        hir::Struct::from_source(db, src).unwrap().ty(db)
+        let src = InFile { file_id: ctx.frange.file_id.into(), value: strukt.clone() };
+        hir::Struct::from_source(db, src)?.ty(db)
     };
 
-    let mut found_new_fn = false;
-
-    let block = module.descendants().filter_map(ast::ImplBlock::cast).find(|impl_blk| {
-        if found_new_fn {
-            return false;
-        }
-
-        let src = hir::Source { file_id: ctx.frange.file_id.into(), value: impl_blk.clone() };
-        let blk = hir::ImplBlock::from_source(db, src).unwrap();
+    let block = module.descendants().filter_map(ast::ImplBlock::cast).find_map(|impl_blk| {
+        let src = InFile { file_id: ctx.frange.file_id.into(), value: impl_blk.clone() };
+        let blk = hir::ImplBlock::from_source(db, src)?;
 
         let same_ty = blk.target_ty(db) == struct_ty;
         let not_trait_impl = blk.target_trait(db).is_none();
 
         if !(same_ty && not_trait_impl) {
-            return false;
+            None
+        } else {
+            Some(impl_blk)
         }
-
-        found_new_fn = has_new_fn(impl_blk);
-        true
     });
 
-    if found_new_fn {
-        None
-    } else {
-        Some(block)
+    if let Some(ref impl_blk) = block {
+        if has_new_fn(impl_blk) {
+            return None;
+        }
     }
+
+    Some(block)
 }
 
 fn has_new_fn(imp: &ast::ImplBlock) -> bool {
     if let Some(il) = imp.item_list() {
         for item in il.impl_items() {
             if let ast::ImplItem::FnDef(f) = item {
-                if f.name().unwrap().text().eq_ignore_ascii_case("new") {
-                    return true;
+                if let Some(name) = f.name() {
+                    if name.text().eq_ignore_ascii_case("new") {
+                        return true;
+                    }
                 }
             }
         }
diff --git a/crates/ra_assists/src/assists/early_return.rs b/crates/ra_assists/src/assists/early_return.rs
index 264412526..023917aca 100644
--- a/crates/ra_assists/src/assists/early_return.rs
+++ b/crates/ra_assists/src/assists/early_return.rs
@@ -83,8 +83,8 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx<impl HirDatabase>) -> Opt
     let parent_container = parent_block.syntax().parent()?.parent()?;
 
     let early_expression: ast::Expr = match parent_container.kind() {
-        WHILE_EXPR | LOOP_EXPR => make::expr_continue().into(),
-        FN_DEF => make::expr_return().into(),
+        WHILE_EXPR | LOOP_EXPR => make::expr_continue(),
+        FN_DEF => make::expr_return(),
         _ => return None,
     };
 
@@ -116,13 +116,13 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx<impl HirDatabase>) -> Opt
                             )
                             .into(),
                         ),
-                        make::expr_path(make::path_from_name_ref(make::name_ref("it"))).into(),
+                        make::expr_path(make::path_from_name_ref(make::name_ref("it"))),
                     );
 
                     let sad_arm = make::match_arm(
                         // FIXME: would be cool to use `None` or `Err(_)` if appropriate
                         once(make::placeholder_pat().into()),
-                        early_expression.into(),
+                        early_expression,
                     );
 
                     make::expr_match(cond_expr, make::match_arm_list(vec![happy_arm, sad_arm]))
@@ -130,7 +130,7 @@ pub(crate) fn convert_to_guarded_return(ctx: AssistCtx<impl HirDatabase>) -> Opt
 
                 let let_stmt = make::let_stmt(
                     make::bind_pat(make::name(&bound_ident.syntax().to_string())).into(),
-                    Some(match_expr.into()),
+                    Some(match_expr),
                 );
                 let let_stmt = if_indent_level.increase_indent(let_stmt);
                 replace(let_stmt.syntax(), &then_block, &parent_block, &if_expr)
diff --git a/crates/ra_assists/src/doc_tests/generated.rs b/crates/ra_assists/src/doc_tests/generated.rs
index 3c716c2d1..4586eeb59 100644
--- a/crates/ra_assists/src/doc_tests/generated.rs
+++ b/crates/ra_assists/src/doc_tests/generated.rs
@@ -3,6 +3,25 @@
 use super::check;
 
 #[test]
+fn doctest_add_custom_impl() {
+    check(
+        "add_custom_impl",
+        r#####"
+#[derive(Deb<|>ug, Display)]
+struct S;
+"#####,
+        r#####"
+#[derive(Display)]
+struct S;
+
+impl Debug for S {
+
+}
+"#####,
+    )
+}
+
+#[test]
 fn doctest_add_derive() {
     check(
         "add_derive",
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index a372bd8b9..98fb20b22 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -95,6 +95,7 @@ mod assists {
     mod add_derive;
     mod add_explicit_type;
     mod add_impl;
+    mod add_custom_impl;
     mod add_new;
     mod apply_demorgan;
     mod invert_if;
@@ -121,6 +122,7 @@ mod assists {
             add_derive::add_derive,
             add_explicit_type::add_explicit_type,
             add_impl::add_impl,
+            add_custom_impl::add_custom_impl,
             add_new::add_new,
             apply_demorgan::apply_demorgan,
             invert_if::invert_if,
diff --git a/crates/ra_assists/src/test_db.rs b/crates/ra_assists/src/test_db.rs
index 523259fd4..d5249f308 100644
--- a/crates/ra_assists/src/test_db.rs
+++ b/crates/ra_assists/src/test_db.rs
@@ -43,5 +43,3 @@ impl FileLoader for TestDB {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
 }
-
-impl hir::debug::HirDebugHelper for TestDB {}
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index 2c9645c00..7744ba85a 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -22,7 +22,7 @@ fn vfs_root_to_id(r: ra_vfs::VfsRoot) -> SourceRootId {
 
 pub fn load_cargo(root: &Path) -> Result<(AnalysisHost, FxHashMap<SourceRootId, PackageRoot>)> {
     let root = std::env::current_dir()?.join(root);
-    let ws = ProjectWorkspace::discover(root.as_ref())?;
+    let ws = ProjectWorkspace::discover(root.as_ref(), &Default::default())?;
     let project_roots = ws.to_roots();
     let (sender, receiver) = unbounded();
     let sender = Box::new(move |t| sender.send(t).unwrap());
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index c7e0d0f0f..12af075f7 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -7,12 +7,14 @@ publish = false
 
 [dependencies]
 pico-args = "0.3.0"
-flexi_logger = "0.14.0"
+env_logger = { version = "0.7.1", default-features = false, features = ["humantime"] }
 
 ra_syntax = { path = "../ra_syntax" }
 ra_ide = { path = "../ra_ide" }
 ra_batch = { path = "../ra_batch" }
-ra_hir = { path = "../ra_hir" }
+hir = { path = "../ra_hir", package = "ra_hir" }
+hir_ty = { path = "../ra_hir_ty", package = "ra_hir_ty" }
+hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
 ra_db = { path = "../ra_db" }
 
 [dependencies.ra_prof]
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index 9b1802a5f..ac65415a5 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -2,8 +2,13 @@
 
 use std::{collections::HashSet, fmt::Write, path::Path, time::Instant};
 
+use hir::{
+    db::{DefDatabase, HirDatabase},
+    AssocItem, Crate, HasSource, HirDisplay, ModuleDef,
+};
+use hir_def::FunctionId;
+use hir_ty::{Ty, TypeWalk};
 use ra_db::SourceDatabaseExt;
-use ra_hir::{AssocItem, Crate, HasSource, HirDisplay, ModuleDef, Ty, TypeWalk};
 use ra_syntax::AstNode;
 
 use crate::{progress_report::ProgressReport, Result, Verbosity};
@@ -101,8 +106,9 @@ pub fn run(
                 continue;
             }
         }
-        let body = f.body(db);
-        let inference_result = f.infer(db);
+        let f_id = FunctionId::from(f);
+        let body = db.body(f_id.into());
+        let inference_result = db.infer(f_id.into());
         for (expr_id, _) in body.exprs.iter() {
             let ty = &inference_result[expr_id];
             num_exprs += 1;
@@ -122,7 +128,8 @@ pub fn run(
             if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr_id) {
                 num_type_mismatches += 1;
                 if verbosity.is_verbose() {
-                    let src = f.body_source_map(db).expr_syntax(expr_id);
+                    let (_, sm) = db.body_with_source_map(f_id.into());
+                    let src = sm.expr_syntax(expr_id);
                     if let Some(src) = src {
                         // FIXME: it might be nice to have a function (on Analysis?) that goes from Source<T> -> (LineCol, LineCol) directly
                         let original_file = src.file_id.original_file(db);
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index fe847e611..3808590ab 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -7,7 +7,6 @@ mod progress_report;
 
 use std::{error::Error, fmt::Write, io::Read};
 
-use flexi_logger::Logger;
 use pico_args::Arguments;
 use ra_ide::{file_structure, Analysis};
 use ra_prof::profile;
@@ -32,7 +31,7 @@ impl Verbosity {
 }
 
 fn main() -> Result<()> {
-    Logger::with_env_or_str("error").start()?;
+    env_logger::try_init()?;
 
     let subcommand = match std::env::args_os().nth(1) {
         None => {
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index b6d851776..2a7ed20d1 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -235,6 +235,15 @@ impl FromStr for Edition {
     }
 }
 
+impl fmt::Display for Edition {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            Edition::Edition2015 => "2015",
+            Edition::Edition2018 => "2018",
+        })
+    }
+}
+
 impl Dependency {
     pub fn crate_id(&self) -> CrateId {
         self.crate_id
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index e79361e7c..7dc31ad3c 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -10,9 +10,11 @@ doctest = false
 [dependencies]
 log = "0.4.5"
 rustc-hash = "1.0"
+either = "1.5"
 
 ra_syntax = { path = "../ra_syntax" }
 ra_db = { path = "../ra_db" }
+ra_prof = { path = "../ra_prof" }
 hir_expand = { path = "../ra_hir_expand", package = "ra_hir_expand" }
 hir_def = { path = "../ra_hir_def", package = "ra_hir_def" }
 hir_ty = { path = "../ra_hir_ty", package = "ra_hir_ty" }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 38d66c2a7..bcfc0d03e 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -1,36 +1,35 @@
 //! FIXME: write short doc here
-
-pub(crate) mod src;
-
 use std::sync::Arc;
 
+use either::Either;
 use hir_def::{
     adt::VariantData,
-    body::{Body, BodySourceMap},
     builtin_type::BuiltinType,
     docs::Documentation,
     expr::{BindingAnnotation, Pat, PatId},
+    nameres::ModuleSource,
     per_ns::PerNs,
     resolver::HasResolver,
     type_ref::{Mutability, TypeRef},
-    AdtId, AstItemDef, ConstId, ContainerId, DefWithBodyId, EnumId, FunctionId, GenericDefId,
-    HasModule, ImplId, LocalEnumVariantId, LocalImportId, LocalModuleId, LocalStructFieldId,
-    Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId, UnionId,
+    AdtId, ConstId, DefWithBodyId, EnumId, FunctionId, HasModule, ImplId, LocalEnumVariantId,
+    LocalModuleId, LocalStructFieldId, Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
+    TypeParamId, UnionId,
 };
 use hir_expand::{
     diagnostics::DiagnosticSink,
-    name::{self, AsName},
-    AstId, MacroDefId,
+    name::{name, AsName},
+    MacroDefId,
+};
+use hir_ty::{
+    autoderef, display::HirFormatter, expr::ExprValidator, ApplicationTy, Canonical, InEnvironment,
+    TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
 };
-use hir_ty::expr::ExprValidator;
-use ra_db::{CrateId, Edition, FileId, FilePosition};
-use ra_syntax::{ast, AstNode, SyntaxNode};
+use ra_db::{CrateId, Edition, FileId};
+use ra_syntax::ast;
 
 use crate::{
     db::{DefDatabase, HirDatabase},
-    ty::display::HirFormatter,
-    ty::{self, InEnvironment, InferenceResult, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk},
-    CallableDef, Either, HirDisplay, Name, Source,
+    CallableDef, HirDisplay, InFile, Name,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
@@ -38,7 +37,7 @@ use crate::{
 /// root module.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Crate {
-    pub(crate) crate_id: CrateId,
+    pub(crate) id: CrateId,
 }
 
 #[derive(Debug)]
@@ -48,91 +47,43 @@ pub struct CrateDependency {
 }
 
 impl Crate {
-    pub fn crate_id(self) -> CrateId {
-        self.crate_id
-    }
-
     pub fn dependencies(self, db: &impl DefDatabase) -> Vec<CrateDependency> {
         db.crate_graph()
-            .dependencies(self.crate_id)
+            .dependencies(self.id)
             .map(|dep| {
-                let krate = Crate { crate_id: dep.crate_id() };
+                let krate = Crate { id: dep.crate_id() };
                 let name = dep.as_name();
                 CrateDependency { krate, name }
             })
             .collect()
     }
 
-    pub fn root_module(self, db: &impl DefDatabase) -> Option<Module> {
-        let module_id = db.crate_def_map(self.crate_id).root;
-        Some(Module::new(self, module_id))
-    }
-
-    pub fn edition(self, db: &impl DefDatabase) -> Edition {
+    // FIXME: add `transitive_reverse_dependencies`.
+    pub fn reverse_dependencies(self, db: &impl DefDatabase) -> Vec<Crate> {
         let crate_graph = db.crate_graph();
-        crate_graph.edition(self.crate_id)
-    }
-
-    pub fn all(db: &impl DefDatabase) -> Vec<Crate> {
-        db.crate_graph().iter().map(|crate_id| Crate { crate_id }).collect()
+        crate_graph
+            .iter()
+            .filter(|&krate| crate_graph.dependencies(krate).any(|it| it.crate_id == self.id))
+            .map(|id| Crate { id })
+            .collect()
     }
-}
-
-pub enum ModuleSource {
-    SourceFile(ast::SourceFile),
-    Module(ast::Module),
-}
 
-impl ModuleSource {
-    pub fn new(
-        db: &impl DefDatabase,
-        file_id: Option<FileId>,
-        decl_id: Option<AstId<ast::Module>>,
-    ) -> ModuleSource {
-        match (file_id, decl_id) {
-            (Some(file_id), _) => {
-                let source_file = db.parse(file_id).tree();
-                ModuleSource::SourceFile(source_file)
-            }
-            (None, Some(item_id)) => {
-                let module = item_id.to_node(db);
-                assert!(module.item_list().is_some(), "expected inline module");
-                ModuleSource::Module(module)
-            }
-            (None, None) => panic!(),
-        }
+    pub fn root_module(self, db: &impl DefDatabase) -> Option<Module> {
+        let module_id = db.crate_def_map(self.id).root;
+        Some(Module::new(self, module_id))
     }
 
-    // FIXME: this methods do not belong here
-    pub fn from_position(db: &impl DefDatabase, position: FilePosition) -> ModuleSource {
-        let parse = db.parse(position.file_id);
-        match &ra_syntax::algo::find_node_at_offset::<ast::Module>(
-            parse.tree().syntax(),
-            position.offset,
-        ) {
-            Some(m) if !m.has_semi() => ModuleSource::Module(m.clone()),
-            _ => {
-                let source_file = parse.tree();
-                ModuleSource::SourceFile(source_file)
-            }
-        }
+    pub fn root_file(self, db: &impl DefDatabase) -> FileId {
+        db.crate_graph().crate_root(self.id)
     }
 
-    pub fn from_child_node(db: &impl DefDatabase, child: Source<&SyntaxNode>) -> ModuleSource {
-        if let Some(m) =
-            child.value.ancestors().filter_map(ast::Module::cast).find(|it| !it.has_semi())
-        {
-            ModuleSource::Module(m)
-        } else {
-            let file_id = child.file_id.original_file(db);
-            let source_file = db.parse(file_id).tree();
-            ModuleSource::SourceFile(source_file)
-        }
+    pub fn edition(self, db: &impl DefDatabase) -> Edition {
+        let crate_graph = db.crate_graph();
+        crate_graph.edition(self.id)
     }
 
-    pub fn from_file_id(db: &impl DefDatabase, file_id: FileId) -> ModuleSource {
-        let source_file = db.parse(file_id).tree();
-        ModuleSource::SourceFile(source_file)
+    pub fn all(db: &impl DefDatabase) -> Vec<Crate> {
+        db.crate_graph().iter().map(|id| Crate { id }).collect()
     }
 }
 
@@ -171,7 +122,7 @@ pub use hir_def::attr::Attrs;
 
 impl Module {
     pub(crate) fn new(krate: Crate, crate_module_id: LocalModuleId) -> Module {
-        Module { id: ModuleId { krate: krate.crate_id, local_id: crate_module_id } }
+        Module { id: ModuleId { krate: krate.id, local_id: crate_module_id } }
     }
 
     /// Name of this module.
@@ -189,7 +140,7 @@ impl Module {
 
     /// Returns the crate this module is part of.
     pub fn krate(self) -> Crate {
-        Crate { crate_id: self.id.krate }
+        Crate { id: self.id.krate }
     }
 
     /// Topmost parent of this module. Every module has a `crate_root`, but some
@@ -200,13 +151,6 @@ impl Module {
         self.with_module_id(def_map.root)
     }
 
-    /// Finds a child module with the specified name.
-    pub fn child(self, db: &impl DefDatabase, name: &Name) -> Option<Module> {
-        let def_map = db.crate_def_map(self.id.krate);
-        let child_id = def_map[self.id.local_id].children.get(name)?;
-        Some(self.with_module_id(*child_id))
-    }
-
     /// Iterates over all child modules.
     pub fn children(self, db: &impl DefDatabase) -> impl Iterator<Item = Module> {
         let def_map = db.crate_def_map(self.id.krate);
@@ -236,13 +180,11 @@ impl Module {
     }
 
     /// Returns a `ModuleScope`: a set of items, visible in this module.
-    pub fn scope(self, db: &impl HirDatabase) -> Vec<(Name, ScopeDef, Option<Import>)> {
+    pub fn scope(self, db: &impl HirDatabase) -> Vec<(Name, ScopeDef)> {
         db.crate_def_map(self.id.krate)[self.id.local_id]
             .scope
             .entries()
-            .map(|(name, res)| {
-                (name.clone(), res.def.into(), res.import.map(|id| Import { parent: self, id }))
-            })
+            .map(|(name, def)| (name.clone(), def.into()))
             .collect()
     }
 
@@ -277,19 +219,14 @@ impl Module {
 
     pub fn impl_blocks(self, db: &impl DefDatabase) -> Vec<ImplBlock> {
         let def_map = db.crate_def_map(self.id.krate);
-        def_map[self.id.local_id].impls.iter().copied().map(ImplBlock::from).collect()
+        def_map[self.id.local_id].scope.impls().map(ImplBlock::from).collect()
     }
 
-    fn with_module_id(self, module_id: LocalModuleId) -> Module {
+    pub(crate) fn with_module_id(self, module_id: LocalModuleId) -> Module {
         Module::new(self.krate(), module_id)
     }
 }
 
-pub struct Import {
-    pub(crate) parent: Module,
-    pub(crate) id: LocalImportId,
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StructField {
     pub(crate) parent: VariantDef,
@@ -307,8 +244,10 @@ impl StructField {
         self.parent.variant_data(db).fields()[self.id].name.clone()
     }
 
-    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
-        db.field_types(self.parent.into())[self.id].clone()
+    pub fn ty(&self, db: &impl HirDatabase) -> Type {
+        let var_id = self.parent.into();
+        let ty = db.field_types(var_id)[self.id].clone();
+        Type::new(db, self.parent.module(db).id.krate.into(), var_id, ty)
     }
 
     pub fn parent_def(&self, _db: &impl HirDatabase) -> VariantDef {
@@ -323,7 +262,7 @@ pub struct Struct {
 
 impl Struct {
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.module(db) }
+        Module { id: self.id.lookup(db).container.module(db) }
     }
 
     pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
@@ -343,21 +282,8 @@ impl Struct {
             .collect()
     }
 
-    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
-        db.struct_data(self.id.into())
-            .variant_data
-            .fields()
-            .iter()
-            .find(|(_id, data)| data.name == *name)
-            .map(|(id, _)| StructField { parent: self.into(), id })
-    }
-
     pub fn ty(self, db: &impl HirDatabase) -> Type {
-        Type::from_def(db, self.id.module(db).krate, self.id)
-    }
-
-    pub fn constructor_ty(self, db: &impl HirDatabase) -> Ty {
-        db.value_ty(self.id.into())
+        Type::from_def(db, self.id.lookup(db).container.module(db).krate, self.id)
     }
 
     fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
@@ -376,11 +302,11 @@ impl Union {
     }
 
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.module(db) }
+        Module { id: self.id.lookup(db).container.module(db) }
     }
 
     pub fn ty(self, db: &impl HirDatabase) -> Type {
-        Type::from_def(db, self.id.module(db).krate, self.id)
+        Type::from_def(db, self.id.lookup(db).container.module(db).krate, self.id)
     }
 
     pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
@@ -392,15 +318,6 @@ impl Union {
             .collect()
     }
 
-    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
-        db.union_data(self.id)
-            .variant_data
-            .fields()
-            .iter()
-            .find(|(_id, data)| data.name == *name)
-            .map(|(id, _)| StructField { parent: self.into(), id })
-    }
-
     fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.union_data(self.id).variant_data.clone()
     }
@@ -413,7 +330,7 @@ pub struct Enum {
 
 impl Enum {
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.module(db) }
+        Module { id: self.id.lookup(db).container.module(db) }
     }
 
     pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
@@ -432,13 +349,8 @@ impl Enum {
             .collect()
     }
 
-    pub fn variant(self, db: &impl DefDatabase, name: &Name) -> Option<EnumVariant> {
-        let id = db.enum_data(self.id).variant(name)?;
-        Some(EnumVariant { parent: self, id })
-    }
-
     pub fn ty(self, db: &impl HirDatabase) -> Type {
-        Type::from_def(db, self.id.module(db).krate, self.id)
+        Type::from_def(db, self.id.lookup(db).container.module(db).krate, self.id)
     }
 }
 
@@ -468,14 +380,6 @@ impl EnumVariant {
             .collect()
     }
 
-    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
-        self.variant_data(db)
-            .fields()
-            .iter()
-            .find(|(_id, data)| data.name == *name)
-            .map(|(id, _)| StructField { parent: self.into(), id })
-    }
-
     pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
         db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
     }
@@ -593,48 +497,8 @@ impl Function {
         db.function_data(self.id).params.clone()
     }
 
-    pub fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
-        db.body_with_source_map(self.id.into()).1
-    }
-
-    pub fn body(self, db: &impl HirDatabase) -> Arc<Body> {
-        db.body(self.id.into())
-    }
-
-    pub fn ty(self, db: &impl HirDatabase) -> Ty {
-        db.value_ty(self.id.into())
-    }
-
-    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.id.into())
-    }
-
-    /// The containing impl block, if this is a method.
-    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
-        match self.container(db) {
-            Some(Container::ImplBlock(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    /// The containing trait, if this is a trait method definition.
-    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
-        match self.container(db) {
-            Some(Container::Trait(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
-        match self.id.lookup(db).container {
-            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
-            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
-            ContainerId::ModuleId(_) => None,
-        }
-    }
-
     pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
-        let infer = self.infer(db);
+        let infer = db.infer(self.id.into());
         infer.add_diagnostics(db, self.id, sink);
         let mut validator = ExprValidator::new(self.id, infer, sink);
         validator.validate_body(db);
@@ -658,34 +522,6 @@ impl Const {
     pub fn name(self, db: &impl HirDatabase) -> Option<Name> {
         db.const_data(self.id).name.clone()
     }
-
-    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.id.into())
-    }
-
-    /// The containing impl block, if this is a type alias.
-    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
-        match self.container(db) {
-            Some(Container::ImplBlock(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    /// The containing trait, if this is a trait type alias definition.
-    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
-        match self.container(db) {
-            Some(Container::Trait(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
-        match self.id.lookup(db).container {
-            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
-            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
-            ContainerId::ModuleId(_) => None,
-        }
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -701,10 +537,6 @@ impl Static {
     pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
         Some(self.module(db).krate())
     }
-
-    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
-        db.infer(self.id.into())
-    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -714,7 +546,7 @@ pub struct Trait {
 
 impl Trait {
     pub fn module(self, db: &impl DefDatabase) -> Module {
-        Module { id: self.id.module(db) }
+        Module { id: self.id.lookup(db).container.module(db) }
     }
 
     pub fn name(self, db: &impl DefDatabase) -> Name {
@@ -749,30 +581,6 @@ impl TypeAlias {
         Some(self.module(db).krate())
     }
 
-    /// The containing impl block, if this is a type alias.
-    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
-        match self.container(db) {
-            Some(Container::ImplBlock(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    /// The containing trait, if this is a trait type alias definition.
-    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
-        match self.container(db) {
-            Some(Container::Trait(it)) => Some(it),
-            _ => None,
-        }
-    }
-
-    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
-        match self.id.lookup(db).container {
-            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
-            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
-            ContainerId::ModuleId(_) => None,
-        }
-    }
-
     pub fn type_ref(self, db: &impl DefDatabase) -> Option<TypeRef> {
         db.type_alias_data(self.id).type_ref.clone()
     }
@@ -791,14 +599,6 @@ pub struct MacroDef {
     pub(crate) id: MacroDefId,
 }
 
-impl MacroDef {}
-
-pub enum Container {
-    Trait(Trait),
-    ImplBlock(ImplBlock),
-}
-impl_froms!(Container: Trait, ImplBlock);
-
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum AssocItem {
     Function(Function),
@@ -819,15 +619,6 @@ impl AssocItem {
             AssocItem::TypeAlias(t) => t.module(db),
         }
     }
-
-    pub fn container(self, db: &impl DefDatabase) -> Container {
-        match self {
-            AssocItem::Function(f) => f.container(db),
-            AssocItem::Const(c) => c.container(db),
-            AssocItem::TypeAlias(t) => t.container(db),
-        }
-        .expect("AssocItem without container")
-    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
@@ -869,7 +660,7 @@ impl Local {
     }
 
     pub fn is_self(self, db: &impl HirDatabase) -> bool {
-        self.name(db) == Some(name::SELF_PARAM)
+        self.name(db) == Some(name![self])
     }
 
     pub fn is_mut(self, db: &impl HirDatabase) -> bool {
@@ -901,18 +692,30 @@ impl Local {
         Type { krate, ty: InEnvironment { value: ty, environment } }
     }
 
-    pub fn source(self, db: &impl HirDatabase) -> Source<Either<ast::BindPat, ast::SelfParam>> {
+    pub fn source(self, db: &impl HirDatabase) -> InFile<Either<ast::BindPat, ast::SelfParam>> {
         let (_body, source_map) = db.body_with_source_map(self.parent.into());
         let src = source_map.pat_syntax(self.pat_id).unwrap(); // Hmm...
         let root = src.file_syntax(db);
-        src.map(|ast| ast.map(|it| it.cast().unwrap().to_node(&root), |it| it.to_node(&root)))
+        src.map(|ast| {
+            ast.map_left(|it| it.cast().unwrap().to_node(&root)).map_right(|it| it.to_node(&root))
+        })
     }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub struct GenericParam {
-    pub(crate) parent: GenericDefId,
-    pub(crate) idx: u32,
+pub struct TypeParam {
+    pub(crate) id: TypeParamId,
+}
+
+impl TypeParam {
+    pub fn name(self, db: &impl HirDatabase) -> Name {
+        let params = db.generic_params(self.id.parent);
+        params.types[self.id.local_id].name.clone()
+    }
+
+    pub fn module(self, db: &impl HirDatabase) -> Module {
+        self.id.parent.module(db).into()
+    }
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -922,11 +725,11 @@ pub struct ImplBlock {
 
 impl ImplBlock {
     pub fn all_in_crate(db: &impl HirDatabase, krate: Crate) -> Vec<ImplBlock> {
-        let impls = db.impls_in_crate(krate.crate_id);
+        let impls = db.impls_in_crate(krate.id);
         impls.all_impls().map(Self::from).collect()
     }
     pub fn for_trait(db: &impl HirDatabase, krate: Crate, trait_: Trait) -> Vec<ImplBlock> {
-        let impls = db.impls_in_crate(krate.crate_id);
+        let impls = db.impls_in_crate(krate.id);
         impls.lookup_impl_blocks_for_trait(trait_.id).map(Self::from).collect()
     }
 
@@ -943,7 +746,10 @@ impl ImplBlock {
         let resolver = self.id.resolver(db);
         let environment = TraitEnvironment::lower(db, &resolver);
         let ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
-        Type { krate: self.id.module(db).krate, ty: InEnvironment { value: ty, environment } }
+        Type {
+            krate: self.id.lookup(db).container.module(db).krate,
+            ty: InEnvironment { value: ty, environment },
+        }
     }
 
     pub fn items(&self, db: &impl DefDatabase) -> Vec<AssocItem> {
@@ -955,11 +761,11 @@ impl ImplBlock {
     }
 
     pub fn module(&self, db: &impl DefDatabase) -> Module {
-        self.id.module(db).into()
+        self.id.lookup(db).container.module(db).into()
     }
 
     pub fn krate(&self, db: &impl DefDatabase) -> Crate {
-        Crate { crate_id: self.module(db).id.krate }
+        Crate { id: self.module(db).id.krate }
     }
 }
 
@@ -970,15 +776,19 @@ pub struct Type {
 }
 
 impl Type {
+    fn new(db: &impl HirDatabase, krate: CrateId, lexical_env: impl HasResolver, ty: Ty) -> Type {
+        let resolver = lexical_env.resolver(db);
+        let environment = TraitEnvironment::lower(db, &resolver);
+        Type { krate, ty: InEnvironment { value: ty, environment } }
+    }
+
     fn from_def(
         db: &impl HirDatabase,
         krate: CrateId,
         def: impl HasResolver + Into<TyDefId>,
     ) -> Type {
-        let resolver = def.resolver(db);
-        let environment = TraitEnvironment::lower(db, &resolver);
         let ty = db.ty(def.into());
-        Type { krate, ty: InEnvironment { value: ty, environment } }
+        Type::new(db, krate, def, ty)
     }
 
     pub fn is_bool(&self) -> bool {
@@ -1028,7 +838,7 @@ impl Type {
     pub fn fields(&self, db: &impl HirDatabase) -> Vec<(StructField, Type)> {
         if let Ty::Apply(a_ty) = &self.ty.value {
             match a_ty.ctor {
-                ty::TypeCtor::Adt(AdtId::StructId(s)) => {
+                TypeCtor::Adt(AdtId::StructId(s)) => {
                     let var_def = s.into();
                     return db
                         .field_types(var_def)
@@ -1050,7 +860,7 @@ impl Type {
         let mut res = Vec::new();
         if let Ty::Apply(a_ty) = &self.ty.value {
             match a_ty.ctor {
-                ty::TypeCtor::Tuple { .. } => {
+                TypeCtor::Tuple { .. } => {
                     for ty in a_ty.parameters.iter() {
                         let ty = ty.clone().subst(&a_ty.parameters);
                         res.push(self.derived(ty));
@@ -1069,11 +879,16 @@ impl Type {
     ) -> Vec<(StructField, Type)> {
         // FIXME: check that ty and def match
         match &self.ty.value {
-            Ty::Apply(a_ty) => def
-                .fields(db)
-                .into_iter()
-                .map(|it| (it, self.derived(it.ty(db).subst(&a_ty.parameters))))
-                .collect(),
+            Ty::Apply(a_ty) => {
+                let field_types = db.field_types(def.into());
+                def.fields(db)
+                    .into_iter()
+                    .map(|it| {
+                        let ty = field_types[it.id].clone().subst(&a_ty.parameters);
+                        (it, self.derived(ty))
+                    })
+                    .collect()
+            }
             _ => Vec::new(),
         }
     }
@@ -1081,10 +896,10 @@ impl Type {
     pub fn autoderef<'a>(&'a self, db: &'a impl HirDatabase) -> impl Iterator<Item = Type> + 'a {
         // There should be no inference vars in types passed here
         // FIXME check that?
-        let canonical = crate::ty::Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: self.ty.value.clone(), num_vars: 0 };
         let environment = self.ty.environment.clone();
         let ty = InEnvironment { value: canonical, environment: environment.clone() };
-        ty::autoderef(db, Some(self.krate), ty)
+        autoderef(db, Some(self.krate), ty)
             .map(|canonical| canonical.value)
             .map(move |ty| self.derived(ty))
     }
@@ -1097,7 +912,7 @@ impl Type {
         krate: Crate,
         mut callback: impl FnMut(AssocItem) -> Option<T>,
     ) -> Option<T> {
-        for krate in self.ty.value.def_crates(db, krate.crate_id)? {
+        for krate in self.ty.value.def_crates(db, krate.id)? {
             let impls = db.impls_in_crate(krate);
 
             for impl_block in impls.lookup_impl_blocks(&self.ty.value) {
@@ -1111,11 +926,6 @@ impl Type {
         None
     }
 
-    // FIXME: remove
-    pub fn into_ty(self) -> Ty {
-        self.ty.value
-    }
-
     pub fn as_adt(&self) -> Option<Adt> {
         let (adt, _subst) = self.ty.value.as_adt()?;
         Some(adt.into())
@@ -1124,15 +934,14 @@ impl Type {
     // FIXME: provide required accessors such that it becomes implementable from outside.
     pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
         match (&self.ty.value, &other.ty.value) {
-            (Ty::Apply(a_original_ty), Ty::Apply(ty::ApplicationTy { ctor, parameters })) => {
-                match ctor {
-                    TypeCtor::Ref(..) => match parameters.as_single() {
-                        Ty::Apply(a_ty) => a_original_ty.ctor == a_ty.ctor,
-                        _ => false,
-                    },
-                    _ => a_original_ty.ctor == *ctor,
-                }
-            }
+            (Ty::Apply(a_original_ty), Ty::Apply(ApplicationTy { ctor, parameters })) => match ctor
+            {
+                TypeCtor::Ref(..) => match parameters.as_single() {
+                    Ty::Apply(a_ty) => a_original_ty.ctor == a_ty.ctor,
+                    _ => false,
+                },
+                _ => a_original_ty.ctor == *ctor,
+            },
             _ => false,
         }
     }
@@ -1155,7 +964,7 @@ impl HirDisplay for Type {
 pub enum ScopeDef {
     ModuleDef(ModuleDef),
     MacroDef(MacroDef),
-    GenericParam(GenericParam),
+    GenericParam(TypeParam),
     ImplSelfType(ImplBlock),
     AdtSelfType(Adt),
     Local(Local),
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
deleted file mode 100644
index bf3ee0834..000000000
--- a/crates/ra_hir/src/code_model/src.rs
+++ /dev/null
@@ -1,128 +0,0 @@
-//! FIXME: write short doc here
-
-use hir_def::{AstItemDef, HasChildSource, HasSource as _, Lookup, VariantId};
-use hir_expand::either::Either;
-use ra_syntax::ast;
-
-use crate::{
-    db::DefDatabase, Const, Enum, EnumVariant, FieldSource, Function, ImplBlock, Import, MacroDef,
-    Module, ModuleSource, Static, Struct, StructField, Trait, TypeAlias, Union,
-};
-
-pub use hir_expand::Source;
-
-pub trait HasSource {
-    type Ast;
-    fn source(self, db: &impl DefDatabase) -> Source<Self::Ast>;
-}
-
-/// NB: Module is !HasSource, because it has two source nodes at the same time:
-/// definition and declaration.
-impl Module {
-    /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
-    pub fn definition_source(self, db: &impl DefDatabase) -> Source<ModuleSource> {
-        let def_map = db.crate_def_map(self.id.krate);
-        let src = def_map[self.id.local_id].definition_source(db);
-        src.map(|it| match it {
-            Either::A(it) => ModuleSource::SourceFile(it),
-            Either::B(it) => ModuleSource::Module(it),
-        })
-    }
-
-    /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
-    /// `None` for the crate root.
-    pub fn declaration_source(self, db: &impl DefDatabase) -> Option<Source<ast::Module>> {
-        let def_map = db.crate_def_map(self.id.krate);
-        def_map[self.id.local_id].declaration_source(db)
-    }
-}
-
-impl HasSource for StructField {
-    type Ast = FieldSource;
-    fn source(self, db: &impl DefDatabase) -> Source<FieldSource> {
-        let var = VariantId::from(self.parent);
-        let src = var.child_source(db);
-        src.map(|it| match it[self.id].clone() {
-            Either::A(it) => FieldSource::Pos(it),
-            Either::B(it) => FieldSource::Named(it),
-        })
-    }
-}
-impl HasSource for Struct {
-    type Ast = ast::StructDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::StructDef> {
-        self.id.source(db)
-    }
-}
-impl HasSource for Union {
-    type Ast = ast::UnionDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::UnionDef> {
-        self.id.source(db)
-    }
-}
-impl HasSource for Enum {
-    type Ast = ast::EnumDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::EnumDef> {
-        self.id.source(db)
-    }
-}
-impl HasSource for EnumVariant {
-    type Ast = ast::EnumVariant;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::EnumVariant> {
-        self.parent.id.child_source(db).map(|map| map[self.id].clone())
-    }
-}
-impl HasSource for Function {
-    type Ast = ast::FnDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::FnDef> {
-        self.id.lookup(db).source(db)
-    }
-}
-impl HasSource for Const {
-    type Ast = ast::ConstDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::ConstDef> {
-        self.id.lookup(db).source(db)
-    }
-}
-impl HasSource for Static {
-    type Ast = ast::StaticDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::StaticDef> {
-        self.id.lookup(db).source(db)
-    }
-}
-impl HasSource for Trait {
-    type Ast = ast::TraitDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::TraitDef> {
-        self.id.source(db)
-    }
-}
-impl HasSource for TypeAlias {
-    type Ast = ast::TypeAliasDef;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::TypeAliasDef> {
-        self.id.lookup(db).source(db)
-    }
-}
-impl HasSource for MacroDef {
-    type Ast = ast::MacroCall;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::MacroCall> {
-        Source { file_id: self.id.ast_id.file_id(), value: self.id.ast_id.to_node(db) }
-    }
-}
-impl HasSource for ImplBlock {
-    type Ast = ast::ImplBlock;
-    fn source(self, db: &impl DefDatabase) -> Source<ast::ImplBlock> {
-        self.id.source(db)
-    }
-}
-impl HasSource for Import {
-    type Ast = Either<ast::UseTree, ast::ExternCrateItem>;
-
-    /// Returns the syntax of the last path segment corresponding to this import
-    fn source(self, db: &impl DefDatabase) -> Source<Self::Ast> {
-        let src = self.parent.definition_source(db);
-        let (_, source_map) = db.raw_items_with_source_map(src.file_id);
-        let root = db.parse_or_expand(src.file_id).unwrap();
-        let ptr = source_map.get(self.id);
-        src.with_value(ptr.map(|it| it.to_node(&root), |it| it.to_node(&root)))
-    }
-}
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index bfae3660b..f5ffd64fa 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -4,8 +4,8 @@ pub use hir_def::db::{
     BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQuery, CrateLangItemsQuery,
     DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery, ExprScopesQuery,
     FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternDatabase, InternDatabaseStorage,
-    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, RawItemsWithSourceMapQuery,
-    StaticDataQuery, StructDataQuery, TraitDataQuery, TypeAliasDataQuery,
+    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery, StructDataQuery,
+    TraitDataQuery, TypeAliasDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, MacroArgQuery, MacroDefQuery, MacroExpandQuery,
diff --git a/crates/ra_hir/src/debug.rs b/crates/ra_hir/src/debug.rs
deleted file mode 100644
index 7a2810f71..000000000
--- a/crates/ra_hir/src/debug.rs
+++ /dev/null
@@ -1,94 +0,0 @@
-//! XXX: This does not work at the moment.
-//!
-//! printf debugging infrastructure for rust-analyzer.
-//!
-//! When you print a hir type, like a module, using `eprintln!("{:?}", module)`,
-//! you usually get back a numeric ID, which doesn't tell you much:
-//! `Module(92)`.
-//!
-//! This module adds convenience `debug` methods to various types, which resolve
-//! the id to a human-readable location info:
-//!
-//! ```not_rust
-//! eprintln!("{:?}", module.debug(db));
-//! =>
-//! Module { name: collections, path: "liballoc/collections/mod.rs" }
-//! ```
-//!
-//! Note that to get this info, we might need to execute queries! So
-//!
-//! * don't use the `debug` methods for logging
-//! * when debugging, be aware that interference is possible.
-
-use std::fmt;
-
-use hir_expand::HirFileId;
-use ra_db::{CrateId, FileId};
-
-use crate::{db::HirDatabase, Crate, Module, Name};
-
-impl Crate {
-    pub fn debug(self, db: &impl HirDebugDatabase) -> impl fmt::Debug + '_ {
-        debug_fn(move |fmt| db.debug_crate(self, fmt))
-    }
-}
-
-impl Module {
-    pub fn debug(self, db: &impl HirDebugDatabase) -> impl fmt::Debug + '_ {
-        debug_fn(move |fmt| db.debug_module(self, fmt))
-    }
-}
-
-pub trait HirDebugHelper: HirDatabase {
-    fn crate_name(&self, _krate: CrateId) -> Option<String> {
-        None
-    }
-    fn file_path(&self, _file_id: FileId) -> Option<String> {
-        None
-    }
-}
-
-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 {
-    fn debug_crate(&self, krate: Crate, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let mut builder = fmt.debug_tuple("Crate");
-        match self.crate_name(krate.crate_id) {
-            Some(name) => builder.field(&name),
-            None => builder.field(&krate.crate_id),
-        }
-        .finish()
-    }
-
-    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).unwrap_or_else(|| "N/A".to_string());
-        fmt.debug_struct("Module")
-            .field("name", &module.name(self).unwrap_or_else(Name::missing))
-            .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 {
-    struct DebugFn<F>(F);
-
-    impl<F: Fn(&mut fmt::Formatter<'_>) -> fmt::Result> fmt::Debug for DebugFn<F> {
-        fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-            (&self.0)(fmt)
-        }
-    }
-
-    DebugFn(f)
-}
diff --git a/crates/ra_hir/src/from_id.rs b/crates/ra_hir/src/from_id.rs
index e96a18d12..75a1a7772 100644
--- a/crates/ra_hir/src/from_id.rs
+++ b/crates/ra_hir/src/from_id.rs
@@ -9,16 +9,10 @@ use hir_def::{
 };
 
 use crate::{
-    Adt, AssocItem, AttrDef, Crate, DefWithBody, EnumVariant, GenericDef, ModuleDef, StructField,
+    Adt, AssocItem, AttrDef, DefWithBody, EnumVariant, GenericDef, ModuleDef, StructField,
     VariantDef,
 };
 
-impl From<ra_db::CrateId> for Crate {
-    fn from(crate_id: ra_db::CrateId) -> Self {
-        Crate { crate_id }
-    }
-}
-
 macro_rules! from_id {
     ($(($id:path, $ty:path)),*) => {$(
         impl From<$id> for $ty {
@@ -26,10 +20,16 @@ macro_rules! from_id {
                 $ty { id }
             }
         }
+        impl From<$ty> for $id {
+            fn from(ty: $ty) -> $id {
+                ty.id
+            }
+        }
     )*}
 }
 
 from_id![
+    (ra_db::CrateId, crate::Crate),
     (hir_def::ModuleId, crate::Module),
     (hir_def::StructId, crate::Struct),
     (hir_def::UnionId, crate::Union),
diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index 9f7c22b21..6314be8d4 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -1,219 +1,140 @@
-//! FIXME: write short doc here
+//! Finds a corresponding hir data structure for a syntax node in a specific
+//! file.
 
-use hir_def::{AstItemDef, LocationCtx, ModuleId};
+use hir_def::{
+    child_by_source::ChildBySource, dyn_map::DynMap, keys, keys::Key, nameres::ModuleSource,
+    ConstId, DefWithBodyId, EnumId, EnumVariantId, FunctionId, GenericDefId, ImplId, ModuleId,
+    StaticId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
+};
 use hir_expand::{name::AsName, AstId, MacroDefId, MacroDefKind};
+use ra_db::FileId;
+use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode, NameOwner},
-    match_ast, AstPtr, SyntaxNode,
+    match_ast, SyntaxNode,
 };
 
 use crate::{
-    db::{AstDatabase, DefDatabase, HirDatabase},
-    AssocItem, Const, DefWithBody, Enum, EnumVariant, FieldSource, Function, HasSource, ImplBlock,
-    Local, MacroDef, Module, ModuleDef, ModuleSource, Source, Static, Struct, StructField, Trait,
-    TypeAlias, Union, VariantDef,
+    db::{DefDatabase, HirDatabase},
+    Const, DefWithBody, Enum, EnumVariant, FieldSource, Function, ImplBlock, InFile, Local,
+    MacroDef, Module, Static, Struct, StructField, Trait, TypeAlias, TypeParam, Union,
 };
 
 pub trait FromSource: Sized {
     type Ast;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self>;
+    fn from_source(db: &impl DefDatabase, src: InFile<Self::Ast>) -> Option<Self>;
 }
 
-impl FromSource for Struct {
-    type Ast = ast::StructDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id = from_source(db, src)?;
-        Some(Struct { id })
-    }
-}
-impl FromSource for Union {
-    type Ast = ast::UnionDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id = from_source(db, src)?;
-        Some(Union { id })
-    }
-}
-impl FromSource for Enum {
-    type Ast = ast::EnumDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id = from_source(db, src)?;
-        Some(Enum { id })
-    }
-}
-impl FromSource for Trait {
-    type Ast = ast::TraitDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id = from_source(db, src)?;
-        Some(Trait { id })
-    }
-}
-impl FromSource for Function {
-    type Ast = ast::FnDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let items = match Container::find(db, src.as_ref().map(|it| it.syntax()))? {
-            Container::Trait(it) => it.items(db),
-            Container::ImplBlock(it) => it.items(db),
-            Container::Module(m) => {
-                return m
-                    .declarations(db)
-                    .into_iter()
-                    .filter_map(|it| match it {
-                        ModuleDef::Function(it) => Some(it),
-                        _ => None,
-                    })
-                    .find(|it| same_source(&it.source(db), &src))
-            }
-        };
-        items
-            .into_iter()
-            .filter_map(|it| match it {
-                AssocItem::Function(it) => Some(it),
-                _ => None,
-            })
-            .find(|it| same_source(&it.source(db), &src))
-    }
+pub trait FromSourceByContainer: Sized {
+    type Ast: AstNode + 'static;
+    type Id: Copy + 'static;
+    const KEY: Key<Self::Ast, Self::Id>;
 }
 
-impl FromSource for Const {
-    type Ast = ast::ConstDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let items = match Container::find(db, src.as_ref().map(|it| it.syntax()))? {
-            Container::Trait(it) => it.items(db),
-            Container::ImplBlock(it) => it.items(db),
-            Container::Module(m) => {
-                return m
-                    .declarations(db)
-                    .into_iter()
-                    .filter_map(|it| match it {
-                        ModuleDef::Const(it) => Some(it),
-                        _ => None,
-                    })
-                    .find(|it| same_source(&it.source(db), &src))
-            }
-        };
-        items
-            .into_iter()
-            .filter_map(|it| match it {
-                AssocItem::Const(it) => Some(it),
-                _ => None,
-            })
-            .find(|it| same_source(&it.source(db), &src))
-    }
-}
-impl FromSource for Static {
-    type Ast = ast::StaticDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let module = match Container::find(db, src.as_ref().map(|it| it.syntax()))? {
-            Container::Module(it) => it,
-            Container::Trait(_) | Container::ImplBlock(_) => return None,
-        };
-        module
-            .declarations(db)
-            .into_iter()
-            .filter_map(|it| match it {
-                ModuleDef::Static(it) => Some(it),
-                _ => None,
-            })
-            .find(|it| same_source(&it.source(db), &src))
+impl<T: FromSourceByContainer> FromSource for T
+where
+    T: From<<T as FromSourceByContainer>::Id>,
+{
+    type Ast = <T as FromSourceByContainer>::Ast;
+    fn from_source(db: &impl DefDatabase, src: InFile<Self::Ast>) -> Option<Self> {
+        analyze_container(db, src.as_ref().map(|it| it.syntax()))[T::KEY]
+            .get(&src)
+            .copied()
+            .map(Self::from)
     }
 }
 
-impl FromSource for TypeAlias {
-    type Ast = ast::TypeAliasDef;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let items = match Container::find(db, src.as_ref().map(|it| it.syntax()))? {
-            Container::Trait(it) => it.items(db),
-            Container::ImplBlock(it) => it.items(db),
-            Container::Module(m) => {
-                return m
-                    .declarations(db)
-                    .into_iter()
-                    .filter_map(|it| match it {
-                        ModuleDef::TypeAlias(it) => Some(it),
-                        _ => None,
-                    })
-                    .find(|it| same_source(&it.source(db), &src))
-            }
-        };
-        items
-            .into_iter()
-            .filter_map(|it| match it {
-                AssocItem::TypeAlias(it) => Some(it),
-                _ => None,
-            })
-            .find(|it| same_source(&it.source(db), &src))
-    }
+macro_rules! from_source_by_container_impls {
+    ($(($hir:ident, $id:ident, $ast:path, $key:path)),* ,) => {$(
+        impl FromSourceByContainer for $hir {
+            type Ast = $ast;
+            type Id = $id;
+            const KEY: Key<Self::Ast, Self::Id> = $key;
+        }
+    )*}
 }
 
+from_source_by_container_impls![
+    (Struct, StructId, ast::StructDef, keys::STRUCT),
+    (Union, UnionId, ast::UnionDef, keys::UNION),
+    (Enum, EnumId, ast::EnumDef, keys::ENUM),
+    (Trait, TraitId, ast::TraitDef, keys::TRAIT),
+    (Function, FunctionId, ast::FnDef, keys::FUNCTION),
+    (Static, StaticId, ast::StaticDef, keys::STATIC),
+    (Const, ConstId, ast::ConstDef, keys::CONST),
+    (TypeAlias, TypeAliasId, ast::TypeAliasDef, keys::TYPE_ALIAS),
+    (ImplBlock, ImplId, ast::ImplBlock, keys::IMPL),
+];
+
 impl FromSource for MacroDef {
     type Ast = ast::MacroCall;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
+    fn from_source(db: &impl DefDatabase, src: InFile<Self::Ast>) -> Option<Self> {
         let kind = MacroDefKind::Declarative;
 
         let module_src = ModuleSource::from_child_node(db, src.as_ref().map(|it| it.syntax()));
-        let module = Module::from_definition(db, Source::new(src.file_id, module_src))?;
-        let krate = module.krate().crate_id();
+        let module = Module::from_definition(db, InFile::new(src.file_id, module_src))?;
+        let krate = Some(module.krate().id);
 
-        let ast_id = AstId::new(src.file_id, db.ast_id_map(src.file_id).ast_id(&src.value));
+        let ast_id = Some(AstId::new(src.file_id, db.ast_id_map(src.file_id).ast_id(&src.value)));
 
         let id: MacroDefId = MacroDefId { krate, ast_id, kind };
         Some(MacroDef { id })
     }
 }
 
-impl FromSource for ImplBlock {
-    type Ast = ast::ImplBlock;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let id = from_source(db, src)?;
-        Some(ImplBlock { id })
-    }
-}
-
 impl FromSource for EnumVariant {
     type Ast = ast::EnumVariant;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
+    fn from_source(db: &impl DefDatabase, src: InFile<Self::Ast>) -> Option<Self> {
         let parent_enum = src.value.parent_enum();
-        let src_enum = Source { file_id: src.file_id, value: parent_enum };
-        let variants = Enum::from_source(db, src_enum)?.variants(db);
-        variants.into_iter().find(|v| same_source(&v.source(db), &src))
+        let src_enum = InFile { file_id: src.file_id, value: parent_enum };
+        let parent_enum = Enum::from_source(db, src_enum)?;
+        parent_enum.id.child_by_source(db)[keys::ENUM_VARIANT]
+            .get(&src)
+            .copied()
+            .map(EnumVariant::from)
     }
 }
 
 impl FromSource for StructField {
     type Ast = FieldSource;
-    fn from_source(db: &(impl DefDatabase + AstDatabase), src: Source<Self::Ast>) -> Option<Self> {
-        let variant_def: VariantDef = match src.value {
-            FieldSource::Named(ref field) => {
+    fn from_source(db: &impl DefDatabase, src: InFile<Self::Ast>) -> Option<Self> {
+        let src = src.as_ref();
+
+        // FIXME this is buggy
+        let variant_id: VariantId = match src.value {
+            FieldSource::Named(field) => {
                 let value = field.syntax().ancestors().find_map(ast::StructDef::cast)?;
-                let src = Source { file_id: src.file_id, value };
+                let src = InFile { file_id: src.file_id, value };
                 let def = Struct::from_source(db, src)?;
-                VariantDef::from(def)
+                def.id.into()
             }
-            FieldSource::Pos(ref field) => {
+            FieldSource::Pos(field) => {
                 let value = field.syntax().ancestors().find_map(ast::EnumVariant::cast)?;
-                let src = Source { file_id: src.file_id, value };
+                let src = InFile { file_id: src.file_id, value };
                 let def = EnumVariant::from_source(db, src)?;
-                VariantDef::from(def)
+                EnumVariantId::from(def).into()
             }
         };
-        variant_def
-            .variant_data(db)
-            .fields()
-            .iter()
-            .map(|(id, _)| StructField { parent: variant_def, id })
-            .find(|f| f.source(db) == src)
+
+        let dyn_map = variant_id.child_by_source(db);
+        match src.value {
+            FieldSource::Pos(it) => dyn_map[keys::TUPLE_FIELD].get(&src.with_value(it.clone())),
+            FieldSource::Named(it) => dyn_map[keys::RECORD_FIELD].get(&src.with_value(it.clone())),
+        }
+        .copied()
+        .map(StructField::from)
     }
 }
 
 impl Local {
-    pub fn from_source(db: &impl HirDatabase, src: Source<ast::BindPat>) -> Option<Self> {
+    pub fn from_source(db: &impl HirDatabase, src: InFile<ast::BindPat>) -> Option<Self> {
         let file_id = src.file_id;
         let parent: DefWithBody = src.value.syntax().ancestors().find_map(|it| {
             let res = match_ast! {
                 match it {
-                    ast::ConstDef(value) => { Const::from_source(db, Source { value, file_id})?.into() },
-                    ast::StaticDef(value) => { Static::from_source(db, Source { value, file_id})?.into() },
-                    ast::FnDef(value) => { Function::from_source(db, Source { value, file_id})?.into() },
+                    ast::ConstDef(value) => { Const::from_source(db, InFile { value, file_id})?.into() },
+                    ast::StaticDef(value) => { Static::from_source(db, InFile { value, file_id})?.into() },
+                    ast::FnDef(value) => { Function::from_source(db, InFile { value, file_id})?.into() },
                     _ => return None,
                 }
             };
@@ -226,84 +147,111 @@ impl Local {
     }
 }
 
+impl TypeParam {
+    pub fn from_source(db: &impl HirDatabase, src: InFile<ast::TypeParam>) -> Option<Self> {
+        let file_id = src.file_id;
+        let parent: GenericDefId = src.value.syntax().ancestors().find_map(|it| {
+            let res = match_ast! {
+                match it {
+                    ast::FnDef(value) => { Function::from_source(db, InFile { value, file_id})?.id.into() },
+                    ast::StructDef(value) => { Struct::from_source(db, InFile { value, file_id})?.id.into() },
+                    ast::EnumDef(value) => { Enum::from_source(db, InFile { value, file_id})?.id.into() },
+                    ast::TraitDef(value) => { Trait::from_source(db, InFile { value, file_id})?.id.into() },
+                    ast::TypeAliasDef(value) => { TypeAlias::from_source(db, InFile { value, file_id})?.id.into() },
+                    ast::ImplBlock(value) => { ImplBlock::from_source(db, InFile { value, file_id})?.id.into() },
+                    _ => return None,
+                }
+            };
+            Some(res)
+        })?;
+        let &id = parent.child_by_source(db)[keys::TYPE_PARAM].get(&src)?;
+        Some(TypeParam { id })
+    }
+}
+
 impl Module {
-    pub fn from_declaration(db: &impl DefDatabase, src: Source<ast::Module>) -> Option<Self> {
+    pub fn from_declaration(db: &impl DefDatabase, src: InFile<ast::Module>) -> Option<Self> {
+        let _p = profile("Module::from_declaration");
         let parent_declaration = src.value.syntax().ancestors().skip(1).find_map(ast::Module::cast);
 
         let parent_module = match parent_declaration {
             Some(parent_declaration) => {
-                let src_parent = Source { file_id: src.file_id, value: parent_declaration };
+                let src_parent = InFile { file_id: src.file_id, value: parent_declaration };
                 Module::from_declaration(db, src_parent)
             }
-            _ => {
-                let src_parent = Source {
-                    file_id: src.file_id,
-                    value: ModuleSource::new(db, Some(src.file_id.original_file(db)), None),
-                };
+            None => {
+                let source_file = db.parse(src.file_id.original_file(db)).tree();
+                let src_parent =
+                    InFile { file_id: src.file_id, value: ModuleSource::SourceFile(source_file) };
                 Module::from_definition(db, src_parent)
             }
         }?;
 
-        let child_name = src.value.name()?;
-        parent_module.child(db, &child_name.as_name())
+        let child_name = src.value.name()?.as_name();
+        let def_map = db.crate_def_map(parent_module.id.krate);
+        let child_id = def_map[parent_module.id.local_id].children.get(&child_name)?;
+        Some(parent_module.with_module_id(*child_id))
     }
 
-    pub fn from_definition(db: &impl DefDatabase, src: Source<ModuleSource>) -> Option<Self> {
+    pub fn from_definition(db: &impl DefDatabase, src: InFile<ModuleSource>) -> Option<Self> {
+        let _p = profile("Module::from_definition");
         match src.value {
             ModuleSource::Module(ref module) => {
                 assert!(!module.has_semi());
                 return Module::from_declaration(
                     db,
-                    Source { file_id: src.file_id, value: module.clone() },
+                    InFile { file_id: src.file_id, value: module.clone() },
                 );
             }
             ModuleSource::SourceFile(_) => (),
         };
 
         let original_file = src.file_id.original_file(db);
+        Module::from_file(db, original_file)
+    }
 
-        let (krate, local_id) = db.relevant_crates(original_file).iter().find_map(|&crate_id| {
+    fn from_file(db: &impl DefDatabase, file: FileId) -> Option<Self> {
+        let _p = profile("Module::from_file");
+        let (krate, local_id) = db.relevant_crates(file).iter().find_map(|&crate_id| {
             let crate_def_map = db.crate_def_map(crate_id);
-            let local_id = crate_def_map.modules_for_file(original_file).next()?;
+            let local_id = crate_def_map.modules_for_file(file).next()?;
             Some((crate_id, local_id))
         })?;
         Some(Module { id: ModuleId { krate, local_id } })
     }
 }
 
-fn from_source<N, DEF>(db: &(impl DefDatabase + AstDatabase), src: Source<N>) -> Option<DEF>
-where
-    N: AstNode,
-    DEF: AstItemDef<N>,
-{
-    let module_src = ModuleSource::from_child_node(db, src.as_ref().map(|it| it.syntax()));
-    let module = Module::from_definition(db, Source::new(src.file_id, module_src))?;
-    let ctx = LocationCtx::new(db, module.id, src.file_id);
-    let items = db.ast_id_map(src.file_id);
-    let item_id = items.ast_id(&src.value);
-    Some(DEF::from_ast_id(ctx, item_id))
-}
-
-enum Container {
-    Trait(Trait),
-    ImplBlock(ImplBlock),
-    Module(Module),
-}
+fn analyze_container(db: &impl DefDatabase, src: InFile<&SyntaxNode>) -> DynMap {
+    let _p = profile("analyze_container");
+    return child_by_source(db, src).unwrap_or_default();
 
-impl Container {
-    fn find(db: &impl DefDatabase, src: Source<&SyntaxNode>) -> Option<Container> {
-        // FIXME: this doesn't try to handle nested declarations
-        for container in src.value.ancestors() {
+    fn child_by_source(db: &impl DefDatabase, src: InFile<&SyntaxNode>) -> Option<DynMap> {
+        for container in src.value.ancestors().skip(1) {
             let res = match_ast! {
                 match container {
                     ast::TraitDef(it) => {
-                        let c = Trait::from_source(db, src.with_value(it))?;
-                        Container::Trait(c)
+                        let def = Trait::from_source(db, src.with_value(it))?;
+                        def.id.child_by_source(db)
                     },
                     ast::ImplBlock(it) => {
-                        let c = ImplBlock::from_source(db, src.with_value(it))?;
-                        Container::ImplBlock(c)
-                     },
+                        let def = ImplBlock::from_source(db, src.with_value(it))?;
+                        def.id.child_by_source(db)
+                    },
+                    ast::FnDef(it) => {
+                        let def = Function::from_source(db, src.with_value(it))?;
+                        DefWithBodyId::from(def.id)
+                            .child_by_source(db)
+                    },
+                    ast::StaticDef(it) => {
+                        let def = Static::from_source(db, src.with_value(it))?;
+                        DefWithBodyId::from(def.id)
+                            .child_by_source(db)
+                    },
+                    ast::ConstDef(it) => {
+                        let def = Const::from_source(db, src.with_value(it))?;
+                        DefWithBodyId::from(def.id)
+                            .child_by_source(db)
+                    },
                     _ => { continue },
                 }
             };
@@ -312,16 +260,6 @@ impl Container {
 
         let module_source = ModuleSource::from_child_node(db, src);
         let c = Module::from_definition(db, src.with_value(module_source))?;
-        Some(Container::Module(c))
+        Some(c.id.child_by_source(db))
     }
 }
-
-/// XXX: AST Nodes and SyntaxNodes have identity equality semantics: nodes are
-/// equal if they point to exactly the same object.
-///
-/// In general, we do not guarantee that we have exactly one instance of a
-/// syntax tree for each file. We probably should add such guarantee, but, for
-/// the time being, we will use identity-less AstPtr comparison.
-fn same_source<N: AstNode>(s1: &Source<N>, s2: &Source<N>) -> bool {
-    s1.as_ref().map(AstPtr::new) == s2.as_ref().map(AstPtr::new)
-}
diff --git a/crates/ra_hir/src/has_source.rs b/crates/ra_hir/src/has_source.rs
new file mode 100644
index 000000000..5541266e2
--- /dev/null
+++ b/crates/ra_hir/src/has_source.rs
@@ -0,0 +1,127 @@
+//! FIXME: write short doc here
+
+use either::Either;
+use hir_def::{
+    nameres::ModuleSource,
+    src::{HasChildSource, HasSource as _},
+    Lookup, VariantId,
+};
+use ra_syntax::ast;
+
+use crate::{
+    db::DefDatabase, Const, Enum, EnumVariant, FieldSource, Function, ImplBlock, MacroDef, Module,
+    Static, Struct, StructField, Trait, TypeAlias, TypeParam, Union,
+};
+
+pub use hir_expand::InFile;
+
+pub trait HasSource {
+    type Ast;
+    fn source(self, db: &impl DefDatabase) -> InFile<Self::Ast>;
+}
+
+/// NB: Module is !HasSource, because it has two source nodes at the same time:
+/// definition and declaration.
+impl Module {
+    /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
+    pub fn definition_source(self, db: &impl DefDatabase) -> InFile<ModuleSource> {
+        let def_map = db.crate_def_map(self.id.krate);
+        def_map[self.id.local_id].definition_source(db)
+    }
+
+    /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
+    /// `None` for the crate root.
+    pub fn declaration_source(self, db: &impl DefDatabase) -> Option<InFile<ast::Module>> {
+        let def_map = db.crate_def_map(self.id.krate);
+        def_map[self.id.local_id].declaration_source(db)
+    }
+}
+
+impl HasSource for StructField {
+    type Ast = FieldSource;
+    fn source(self, db: &impl DefDatabase) -> InFile<FieldSource> {
+        let var = VariantId::from(self.parent);
+        let src = var.child_source(db);
+        src.map(|it| match it[self.id].clone() {
+            Either::Left(it) => FieldSource::Pos(it),
+            Either::Right(it) => FieldSource::Named(it),
+        })
+    }
+}
+impl HasSource for Struct {
+    type Ast = ast::StructDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::StructDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for Union {
+    type Ast = ast::UnionDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::UnionDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for Enum {
+    type Ast = ast::EnumDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::EnumDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for EnumVariant {
+    type Ast = ast::EnumVariant;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::EnumVariant> {
+        self.parent.id.child_source(db).map(|map| map[self.id].clone())
+    }
+}
+impl HasSource for Function {
+    type Ast = ast::FnDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::FnDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for Const {
+    type Ast = ast::ConstDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::ConstDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for Static {
+    type Ast = ast::StaticDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::StaticDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for Trait {
+    type Ast = ast::TraitDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::TraitDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for TypeAlias {
+    type Ast = ast::TypeAliasDef;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::TypeAliasDef> {
+        self.id.lookup(db).source(db)
+    }
+}
+impl HasSource for MacroDef {
+    type Ast = ast::MacroCall;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::MacroCall> {
+        InFile {
+            file_id: self.id.ast_id.expect("MacroDef without ast_id").file_id,
+            value: self.id.ast_id.expect("MacroDef without ast_id").to_node(db),
+        }
+    }
+}
+impl HasSource for ImplBlock {
+    type Ast = ast::ImplBlock;
+    fn source(self, db: &impl DefDatabase) -> InFile<ast::ImplBlock> {
+        self.id.lookup(db).source(db)
+    }
+}
+
+impl HasSource for TypeParam {
+    type Ast = Either<ast::TraitDef, ast::TypeParam>;
+    fn source(self, db: &impl DefDatabase) -> InFile<Self::Ast> {
+        let child_source = self.id.parent.child_source(db);
+        child_source.map(|it| it[self.id.local_id].clone())
+    }
+}
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3c12c61f0..0008a8858 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -26,42 +26,38 @@ macro_rules! impl_froms {
     }
 }
 
-pub mod debug;
-
 pub mod db;
 pub mod source_binder;
 
-mod ty;
 pub mod diagnostics;
 
 mod from_id;
 mod code_model;
 
-pub mod from_source;
+mod has_source;
+mod from_source;
 
 pub use crate::{
     code_model::{
-        src::HasSource, Adt, AssocItem, AttrDef, Const, Container, Crate, CrateDependency,
-        DefWithBody, Docs, Enum, EnumVariant, FieldSource, Function, GenericDef, GenericParam,
-        HasAttrs, ImplBlock, Import, Local, MacroDef, Module, ModuleDef, ModuleSource, ScopeDef,
-        Static, Struct, StructField, Trait, Type, TypeAlias, Union, VariantDef,
+        Adt, AssocItem, AttrDef, Const, Crate, CrateDependency, DefWithBody, Docs, Enum,
+        EnumVariant, FieldSource, Function, GenericDef, HasAttrs, ImplBlock, Local, MacroDef,
+        Module, ModuleDef, ScopeDef, Static, Struct, StructField, Trait, Type, TypeAlias,
+        TypeParam, Union, VariantDef,
     },
     from_source::FromSource,
+    has_source::HasSource,
     source_binder::{PathResolution, ScopeEntryWithSyntax, SourceAnalyzer},
-    ty::{
-        display::HirDisplay,
-        primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness, Uncertain},
-        ApplicationTy, CallableDef, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
-    },
 };
 
 pub use hir_def::{
     body::scope::ExprScopes,
     builtin_type::BuiltinType,
     docs::Documentation,
-    path::{Path, PathKind},
+    nameres::ModuleSource,
+    path::{ModPath, Path, PathKind},
     type_ref::Mutability,
 };
 pub use hir_expand::{
-    either::Either, name::Name, HirFileId, MacroCallId, MacroCallLoc, MacroDefId, MacroFile, Source,
+    name::Name, HirFileId, InFile, MacroCallId, MacroCallLoc, MacroDefId, MacroFile, Origin,
 };
+pub use hir_ty::{display::HirDisplay, CallableDef};
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 76c493f1a..85b378483 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -7,19 +7,26 @@
 //! purely for "IDE needs".
 use std::sync::Arc;
 
+use either::Either;
 use hir_def::{
     body::{
         scope::{ExprScopes, ScopeId},
         BodySourceMap,
     },
     expr::{ExprId, PatId},
-    path::known,
+    nameres::ModuleSource,
+    path::path,
     resolver::{self, resolver_for_scope, HasResolver, Resolver, TypeNs, ValueNs},
     AssocItemId, DefWithBodyId,
 };
 use hir_expand::{
-    hygiene::Hygiene, name::AsName, AstId, HirFileId, MacroCallId, MacroFileKind, Source,
+    hygiene::Hygiene, name::AsName, AstId, HirFileId, InFile, MacroCallId, MacroCallKind,
 };
+use hir_ty::{
+    method_resolution::{self, implements_trait},
+    Canonical, InEnvironment, InferenceResult, TraitEnvironment, Ty,
+};
+use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode},
     match_ast, AstPtr,
@@ -28,16 +35,12 @@ use ra_syntax::{
 };
 
 use crate::{
-    db::HirDatabase,
-    ty::{
-        method_resolution::{self, implements_trait},
-        InEnvironment, TraitEnvironment, Ty,
-    },
-    Adt, AssocItem, Const, DefWithBody, Either, Enum, EnumVariant, FromSource, Function,
-    GenericParam, Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Type, TypeAlias,
+    db::HirDatabase, Adt, AssocItem, Const, DefWithBody, Enum, EnumVariant, FromSource, Function,
+    ImplBlock, Local, MacroDef, Name, Path, ScopeDef, Static, Struct, Trait, Type, TypeAlias,
+    TypeParam,
 };
 
-fn try_get_resolver_for_node(db: &impl HirDatabase, node: Source<&SyntaxNode>) -> Option<Resolver> {
+fn try_get_resolver_for_node(db: &impl HirDatabase, node: InFile<&SyntaxNode>) -> Option<Resolver> {
     match_ast! {
         match (node.value) {
             ast::Module(it) => {
@@ -45,7 +48,7 @@ fn try_get_resolver_for_node(db: &impl HirDatabase, node: Source<&SyntaxNode>) -
                 Some(crate::Module::from_declaration(db, src)?.id.resolver(db))
             },
              ast::SourceFile(it) => {
-                let src = node.with_value(crate::ModuleSource::SourceFile(it));
+                let src = node.with_value(ModuleSource::SourceFile(it));
                 Some(crate::Module::from_definition(db, src)?.id.resolver(db))
             },
             ast::StructDef(it) => {
@@ -56,6 +59,14 @@ fn try_get_resolver_for_node(db: &impl HirDatabase, node: Source<&SyntaxNode>) -
                 let src = node.with_value(it);
                 Some(Enum::from_source(db, src)?.id.resolver(db))
             },
+            ast::ImplBlock(it) => {
+                let src = node.with_value(it);
+                Some(ImplBlock::from_source(db, src)?.id.resolver(db))
+            },
+            ast::TraitDef(it) => {
+                let src = node.with_value(it);
+                Some(Trait::from_source(db, src)?.id.resolver(db))
+            },
             _ => match node.value.kind() {
                 FN_DEF | CONST_DEF | STATIC_DEF => {
                     let def = def_with_body_from_child_node(db, node)?;
@@ -71,14 +82,16 @@ fn try_get_resolver_for_node(db: &impl HirDatabase, node: Source<&SyntaxNode>) -
 
 fn def_with_body_from_child_node(
     db: &impl HirDatabase,
-    child: Source<&SyntaxNode>,
+    child: InFile<&SyntaxNode>,
 ) -> Option<DefWithBody> {
-    child.value.ancestors().find_map(|node| {
+    let _p = profile("def_with_body_from_child_node");
+    child.cloned().ancestors_with_macros(db).find_map(|node| {
+        let n = &node.value;
         match_ast! {
-            match node {
-                ast::FnDef(def)  => { return Function::from_source(db, child.with_value(def)).map(DefWithBody::from); },
-                ast::ConstDef(def) => { return Const::from_source(db, child.with_value(def)).map(DefWithBody::from); },
-                ast::StaticDef(def) => { return Static::from_source(db, child.with_value(def)).map(DefWithBody::from); },
+            match n {
+                ast::FnDef(def)  => { return Function::from_source(db, node.with_value(def)).map(DefWithBody::from); },
+                ast::ConstDef(def) => { return Const::from_source(db, node.with_value(def)).map(DefWithBody::from); },
+                ast::StaticDef(def) => { return Static::from_source(db, node.with_value(def)).map(DefWithBody::from); },
                 _ => { None },
             }
         }
@@ -93,7 +106,7 @@ pub struct SourceAnalyzer {
     resolver: Resolver,
     body_owner: Option<DefWithBody>,
     body_source_map: Option<Arc<BodySourceMap>>,
-    infer: Option<Arc<crate::ty::InferenceResult>>,
+    infer: Option<Arc<InferenceResult>>,
     scopes: Option<Arc<ExprScopes>>,
 }
 
@@ -104,7 +117,7 @@ pub enum PathResolution {
     /// A local binding (only value namespace)
     Local(Local),
     /// A generic parameter
-    GenericParam(GenericParam),
+    TypeParam(TypeParam),
     SelfType(crate::ImplBlock),
     Macro(MacroDef),
     AssocItem(crate::AssocItem),
@@ -132,8 +145,8 @@ pub struct ReferenceDescriptor {
     pub name: String,
 }
 
+#[derive(Debug)]
 pub struct Expansion {
-    macro_file_kind: MacroFileKind,
     macro_call_id: MacroCallId,
 }
 
@@ -141,23 +154,24 @@ impl Expansion {
     pub fn map_token_down(
         &self,
         db: &impl HirDatabase,
-        token: Source<&SyntaxToken>,
-    ) -> Option<Source<SyntaxToken>> {
+        token: InFile<&SyntaxToken>,
+    ) -> Option<InFile<SyntaxToken>> {
         let exp_info = self.file_id().expansion_info(db)?;
         exp_info.map_token_down(token)
     }
 
     pub fn file_id(&self) -> HirFileId {
-        self.macro_call_id.as_file(self.macro_file_kind)
+        self.macro_call_id.as_file()
     }
 }
 
 impl SourceAnalyzer {
     pub fn new(
         db: &impl HirDatabase,
-        node: Source<&SyntaxNode>,
+        node: InFile<&SyntaxNode>,
         offset: Option<TextUnit>,
     ) -> SourceAnalyzer {
+        let _p = profile("SourceAnalyzer::new");
         let def_with_body = def_with_body_from_child_node(db, node);
         if let Some(def) = def_with_body {
             let (_body, source_map) = db.body_with_source_map(def.into());
@@ -192,12 +206,12 @@ impl SourceAnalyzer {
     }
 
     fn expr_id(&self, expr: &ast::Expr) -> Option<ExprId> {
-        let src = Source { file_id: self.file_id, value: expr };
+        let src = InFile { file_id: self.file_id, value: expr };
         self.body_source_map.as_ref()?.node_expr(src)
     }
 
     fn pat_id(&self, pat: &ast::Pat) -> Option<PatId> {
-        let src = Source { file_id: self.file_id, value: pat };
+        let src = InFile { file_id: self.file_id, value: pat };
         self.body_source_map.as_ref()?.node_pat(src)
     }
 
@@ -226,7 +240,13 @@ impl SourceAnalyzer {
     }
 
     pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<crate::StructField> {
-        let expr_id = self.expr_id(&field.expr()?)?;
+        let expr_id = match field.expr() {
+            Some(it) => self.expr_id(&it)?,
+            None => {
+                let src = InFile { file_id: self.file_id, value: field };
+                self.body_source_map.as_ref()?.field_init_shorthand_expr(src)?
+            }
+        };
         self.infer.as_ref()?.record_field_resolution(expr_id).map(|it| it.into())
     }
 
@@ -243,11 +263,11 @@ impl SourceAnalyzer {
     pub fn resolve_macro_call(
         &self,
         db: &impl HirDatabase,
-        macro_call: Source<&ast::MacroCall>,
+        macro_call: InFile<&ast::MacroCall>,
     ) -> Option<MacroDef> {
         let hygiene = Hygiene::new(db, macro_call.file_id);
         let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &hygiene))?;
-        self.resolver.resolve_path_as_macro(db, &path).map(|it| it.into())
+        self.resolver.resolve_path_as_macro(db, path.mod_path()).map(|it| it.into())
     }
 
     pub fn resolve_hir_path(
@@ -255,43 +275,42 @@ impl SourceAnalyzer {
         db: &impl HirDatabase,
         path: &crate::Path,
     ) -> Option<PathResolution> {
-        let types = self.resolver.resolve_path_in_type_ns_fully(db, &path).map(|ty| match ty {
-            TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
-            TypeNs::GenericParam(idx) => PathResolution::GenericParam(GenericParam {
-                parent: self.resolver.generic_def().unwrap(),
-                idx,
-            }),
-            TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
-                PathResolution::Def(Adt::from(it).into())
-            }
-            TypeNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
-            TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
-            TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
-            TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
-        });
-        let values = self.resolver.resolve_path_in_value_ns_fully(db, &path).and_then(|val| {
-            let res = match val {
-                ValueNs::LocalBinding(pat_id) => {
-                    let var = Local { parent: self.body_owner?, pat_id };
-                    PathResolution::Local(var)
+        let types =
+            self.resolver.resolve_path_in_type_ns_fully(db, path.mod_path()).map(|ty| match ty {
+                TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
+                TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
+                TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
+                    PathResolution::Def(Adt::from(it).into())
                 }
-                ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
-                ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
-                ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
-                ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
-                ValueNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
-            };
-            Some(res)
-        });
+                TypeNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+                TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
+                TypeNs::BuiltinType(it) => PathResolution::Def(it.into()),
+                TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
+            });
+        let values =
+            self.resolver.resolve_path_in_value_ns_fully(db, path.mod_path()).and_then(|val| {
+                let res = match val {
+                    ValueNs::LocalBinding(pat_id) => {
+                        let var = Local { parent: self.body_owner?, pat_id };
+                        PathResolution::Local(var)
+                    }
+                    ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
+                    ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
+                    ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
+                    ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
+                    ValueNs::EnumVariantId(it) => PathResolution::Def(EnumVariant::from(it).into()),
+                };
+                Some(res)
+            });
 
         let items = self
             .resolver
-            .resolve_module_path(db, &path)
+            .resolve_module_path_in_items(db, path.mod_path())
             .take_types()
             .map(|it| PathResolution::Def(it.into()));
         types.or(values).or(items).or_else(|| {
             self.resolver
-                .resolve_path_as_macro(db, &path)
+                .resolve_path_as_macro(db, path.mod_path())
                 .map(|def| PathResolution::Macro(def.into()))
         })
     }
@@ -318,7 +337,7 @@ impl SourceAnalyzer {
         let name = name_ref.as_name();
         let source_map = self.body_source_map.as_ref()?;
         let scopes = self.scopes.as_ref()?;
-        let scope = scope_for(scopes, source_map, Source::new(self.file_id, name_ref.syntax()))?;
+        let scope = scope_for(scopes, source_map, InFile::new(self.file_id, name_ref.syntax()))?;
         let entry = scopes.resolve_name_in_scope(scope, &name)?;
         Some(ScopeEntryWithSyntax {
             name: entry.name().clone(),
@@ -332,10 +351,7 @@ impl SourceAnalyzer {
                 resolver::ScopeDef::PerNs(it) => it.into(),
                 resolver::ScopeDef::ImplSelfType(it) => ScopeDef::ImplSelfType(it.into()),
                 resolver::ScopeDef::AdtSelfType(it) => ScopeDef::AdtSelfType(it.into()),
-                resolver::ScopeDef::GenericParam(idx) => {
-                    let parent = self.resolver.generic_def().unwrap();
-                    ScopeDef::GenericParam(GenericParam { parent, idx })
-                }
+                resolver::ScopeDef::GenericParam(id) => ScopeDef::GenericParam(TypeParam { id }),
                 resolver::ScopeDef::Local(pat_id) => {
                     let parent = self.resolver.body_owner().unwrap().into();
                     ScopeDef::Local(Local { parent, pat_id })
@@ -349,7 +365,7 @@ impl SourceAnalyzer {
     // should switch to general reference search infra there.
     pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
         let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
-        let ptr = Either::A(AstPtr::new(&ast::Pat::from(pat.clone())));
+        let ptr = Either::Left(AstPtr::new(&ast::Pat::from(pat.clone())));
         fn_def
             .syntax()
             .descendants()
@@ -375,7 +391,7 @@ impl SourceAnalyzer {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = crate::ty::Canonical { value: ty.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: ty.ty.value.clone(), num_vars: 0 };
         method_resolution::iterate_method_candidates(
             &canonical,
             db,
@@ -399,7 +415,7 @@ impl SourceAnalyzer {
         // There should be no inference vars in types passed here
         // FIXME check that?
         // FIXME replace Unknown by bound vars here
-        let canonical = crate::ty::Canonical { value: ty.ty.value.clone(), num_vars: 0 };
+        let canonical = Canonical { value: ty.ty.value.clone(), num_vars: 0 };
         method_resolution::iterate_method_candidates(
             &canonical,
             db,
@@ -410,24 +426,10 @@ impl SourceAnalyzer {
         )
     }
 
-    // pub fn autoderef<'a>(
-    //     &'a self,
-    //     db: &'a impl HirDatabase,
-    //     ty: Ty,
-    // ) -> impl Iterator<Item = Ty> + 'a {
-    //     // There should be no inference vars in types passed here
-    //     // FIXME check that?
-    //     let canonical = crate::ty::Canonical { value: ty, num_vars: 0 };
-    //     let krate = self.resolver.krate();
-    //     let environment = TraitEnvironment::lower(db, &self.resolver);
-    //     let ty = crate::ty::InEnvironment { value: canonical, environment };
-    //     crate::ty::autoderef(db, krate, ty).map(|canonical| canonical.value)
-    // }
-
     /// Checks that particular type `ty` implements `std::future::Future`.
     /// This function is used in `.await` syntax completion.
-    pub fn impls_future(&self, db: &impl HirDatabase, ty: Ty) -> bool {
-        let std_future_path = known::std_future_future();
+    pub fn impls_future(&self, db: &impl HirDatabase, ty: Type) -> bool {
+        let std_future_path = path![std::future::Future];
 
         let std_future_trait = match self.resolver.resolve_known_trait(db, &std_future_path) {
             Some(it) => it.into(),
@@ -439,43 +441,40 @@ impl SourceAnalyzer {
             _ => return false,
         };
 
-        let canonical_ty = crate::ty::Canonical { value: ty, num_vars: 0 };
+        let canonical_ty = Canonical { value: ty.ty.value, num_vars: 0 };
         implements_trait(&canonical_ty, db, &self.resolver, krate.into(), std_future_trait)
     }
 
     pub fn expand(
         &self,
         db: &impl HirDatabase,
-        macro_call: Source<&ast::MacroCall>,
+        macro_call: InFile<&ast::MacroCall>,
     ) -> Option<Expansion> {
         let def = self.resolve_macro_call(db, macro_call)?.id;
         let ast_id = AstId::new(
             macro_call.file_id,
             db.ast_id_map(macro_call.file_id).ast_id(macro_call.value),
         );
-        Some(Expansion {
-            macro_call_id: def.as_call_id(db, ast_id),
-            macro_file_kind: to_macro_file_kind(macro_call.value),
-        })
+        Some(Expansion { macro_call_id: def.as_call_id(db, MacroCallKind::FnLike(ast_id)) })
     }
 }
 
 fn scope_for(
     scopes: &ExprScopes,
     source_map: &BodySourceMap,
-    node: Source<&SyntaxNode>,
+    node: InFile<&SyntaxNode>,
 ) -> Option<ScopeId> {
     node.value
         .ancestors()
         .filter_map(ast::Expr::cast)
-        .filter_map(|it| source_map.node_expr(Source::new(node.file_id, &it)))
+        .filter_map(|it| source_map.node_expr(InFile::new(node.file_id, &it)))
         .find_map(|it| scopes.scope_for(it))
 }
 
 fn scope_for_offset(
     scopes: &ExprScopes,
     source_map: &BodySourceMap,
-    offset: Source<TextUnit>,
+    offset: InFile<TextUnit>,
 ) -> Option<ScopeId> {
     scopes
         .scope_by_expr()
@@ -540,35 +539,3 @@ fn adjust(
         })
         .map(|(_ptr, scope)| *scope)
 }
-
-/// Given a `ast::MacroCall`, return what `MacroKindFile` it belongs to.
-/// FIXME: Not completed
-fn to_macro_file_kind(macro_call: &ast::MacroCall) -> MacroFileKind {
-    let syn = macro_call.syntax();
-    let parent = match syn.parent() {
-        Some(it) => it,
-        None => {
-            // FIXME:
-            // If it is root, which means the parent HirFile
-            // MacroKindFile must be non-items
-            // return expr now.
-            return MacroFileKind::Expr;
-        }
-    };
-
-    match parent.kind() {
-        MACRO_ITEMS | SOURCE_FILE => MacroFileKind::Items,
-        LET_STMT => {
-            // FIXME: Handle Pattern
-            MacroFileKind::Expr
-        }
-        EXPR_STMT => MacroFileKind::Statements,
-        BLOCK => MacroFileKind::Statements,
-        ARG_LIST => MacroFileKind::Expr,
-        TRY_EXPR => MacroFileKind::Expr,
-        _ => {
-            // Unknown , Just guess it is `Items`
-            MacroFileKind::Items
-        }
-    }
-}
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
deleted file mode 100644
index 4ed69c00d..000000000
--- a/crates/ra_hir/src/ty.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-//! The type system. We currently use this to infer types for completion, hover
-//! information and various assists.
-
-pub use hir_ty::*;
diff --git a/crates/ra_hir_def/Cargo.toml b/crates/ra_hir_def/Cargo.toml
index 7e65f4c1d..2c368f690 100644
--- a/crates/ra_hir_def/Cargo.toml
+++ b/crates/ra_hir_def/Cargo.toml
@@ -11,6 +11,9 @@ doctest = false
 log = "0.4.5"
 once_cell = "1.0.1"
 rustc-hash = "1.0"
+either = "1.5"
+anymap = "0.12"
+drop_bomb = "0.1.4"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index 3666529b0..d9ea693e3 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -2,17 +2,18 @@
 
 use std::sync::Arc;
 
+use either::Either;
 use hir_expand::{
-    either::Either,
     name::{AsName, Name},
-    Source,
+    InFile,
 };
 use ra_arena::{map::ArenaMap, Arena};
+use ra_prof::profile;
 use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
-    db::DefDatabase, trace::Trace, type_ref::TypeRef, AstItemDef, EnumId, HasChildSource,
-    LocalEnumVariantId, LocalStructFieldId, StructId, UnionId, VariantId,
+    db::DefDatabase, src::HasChildSource, src::HasSource, trace::Trace, type_ref::TypeRef, EnumId,
+    LocalEnumVariantId, LocalStructFieldId, Lookup, StructId, UnionId, VariantId,
 };
 
 /// Note that we use `StructData` for unions as well!
@@ -50,14 +51,14 @@ pub struct StructFieldData {
 
 impl StructData {
     pub(crate) fn struct_data_query(db: &impl DefDatabase, id: StructId) -> Arc<StructData> {
-        let src = id.source(db);
+        let src = id.lookup(db).source(db);
         let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let variant_data = VariantData::new(src.value.kind());
         let variant_data = Arc::new(variant_data);
         Arc::new(StructData { name, variant_data })
     }
     pub(crate) fn union_data_query(db: &impl DefDatabase, id: UnionId) -> Arc<StructData> {
-        let src = id.source(db);
+        let src = id.lookup(db).source(db);
         let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let variant_data = VariantData::new(
             src.value
@@ -72,7 +73,8 @@ impl StructData {
 
 impl EnumData {
     pub(crate) fn enum_data_query(db: &impl DefDatabase, e: EnumId) -> Arc<EnumData> {
-        let src = e.source(db);
+        let _p = profile("enum_data_query");
+        let src = e.lookup(db).source(db);
         let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let mut trace = Trace::new_for_arena();
         lower_enum(&mut trace, &src.value);
@@ -88,8 +90,8 @@ impl EnumData {
 impl HasChildSource for EnumId {
     type ChildId = LocalEnumVariantId;
     type Value = ast::EnumVariant;
-    fn child_source(&self, db: &impl DefDatabase) -> Source<ArenaMap<Self::ChildId, Self::Value>> {
-        let src = self.source(db);
+    fn child_source(&self, db: &impl DefDatabase) -> InFile<ArenaMap<Self::ChildId, Self::Value>> {
+        let src = self.lookup(db).source(db);
         let mut trace = Trace::new_for_map();
         lower_enum(&mut trace, &src.value);
         src.with_value(trace.into_map())
@@ -145,7 +147,7 @@ impl HasChildSource for VariantId {
     type ChildId = LocalStructFieldId;
     type Value = Either<ast::TupleFieldDef, ast::RecordFieldDef>;
 
-    fn child_source(&self, db: &impl DefDatabase) -> Source<ArenaMap<Self::ChildId, Self::Value>> {
+    fn child_source(&self, db: &impl DefDatabase) -> InFile<ArenaMap<Self::ChildId, Self::Value>> {
         let src = match self {
             VariantId::EnumVariantId(it) => {
                 // I don't really like the fact that we call into parent source
@@ -153,8 +155,8 @@ impl HasChildSource for VariantId {
                 let src = it.parent.child_source(db);
                 src.map(|map| map[it.local_id].kind())
             }
-            VariantId::StructId(it) => it.source(db).map(|it| it.kind()),
-            VariantId::UnionId(it) => it.source(db).map(|it| {
+            VariantId::StructId(it) => it.lookup(db).source(db).map(|it| it.kind()),
+            VariantId::UnionId(it) => it.lookup(db).source(db).map(|it| {
                 it.record_field_def_list()
                     .map(ast::StructKind::Record)
                     .unwrap_or(ast::StructKind::Unit)
@@ -184,7 +186,7 @@ fn lower_struct(
         ast::StructKind::Tuple(fl) => {
             for (i, fd) in fl.fields().enumerate() {
                 trace.alloc(
-                    || Either::A(fd.clone()),
+                    || Either::Left(fd.clone()),
                     || StructFieldData {
                         name: Name::new_tuple_field(i),
                         type_ref: TypeRef::from_ast_opt(fd.type_ref()),
@@ -196,7 +198,7 @@ fn lower_struct(
         ast::StructKind::Record(fl) => {
             for fd in fl.fields() {
                 trace.alloc(
-                    || Either::B(fd.clone()),
+                    || Either::Right(fd.clone()),
                     || StructFieldData {
                         name: fd.name().map(|n| n.as_name()).unwrap_or_else(Name::missing),
                         type_ref: TypeRef::from_ast_opt(fd.ascribed_type()),
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index fffb22201..9efa4970c 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -2,7 +2,8 @@
 
 use std::{ops, sync::Arc};
 
-use hir_expand::{either::Either, hygiene::Hygiene, AstId, Source};
+use either::Either;
+use hir_expand::{hygiene::Hygiene, AstId, InFile};
 use mbe::ast_to_token_tree;
 use ra_syntax::{
     ast::{self, AstNode, AttrsOwner},
@@ -11,7 +12,7 @@ use ra_syntax::{
 use tt::Subtree;
 
 use crate::{
-    db::DefDatabase, path::Path, AdtId, AstItemDef, AttrDefId, HasChildSource, HasSource, Lookup,
+    db::DefDatabase, path::ModPath, src::HasChildSource, src::HasSource, AdtId, AttrDefId, Lookup,
 };
 
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
@@ -44,8 +45,8 @@ impl Attrs {
             AttrDefId::StructFieldId(it) => {
                 let src = it.parent.child_source(db);
                 match &src.value[it.local_id] {
-                    Either::A(_tuple) => Attrs::default(),
-                    Either::B(record) => Attrs::from_attrs_owner(db, src.with_value(record)),
+                    Either::Left(_tuple) => Attrs::default(),
+                    Either::Right(record) => Attrs::from_attrs_owner(db, src.with_value(record)),
                 }
             }
             AttrDefId::EnumVariantId(var_id) => {
@@ -54,13 +55,15 @@ impl Attrs {
                 Attrs::from_attrs_owner(db, src.map(|it| it as &dyn AttrsOwner))
             }
             AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-                AdtId::EnumId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-                AdtId::UnionId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
+                AdtId::StructId(it) => attrs_from_loc(it.lookup(db), db),
+                AdtId::EnumId(it) => attrs_from_loc(it.lookup(db), db),
+                AdtId::UnionId(it) => attrs_from_loc(it.lookup(db), db),
             },
-            AttrDefId::TraitId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
-            AttrDefId::MacroDefId(it) => attrs_from_ast(it.ast_id, db),
-            AttrDefId::ImplId(it) => attrs_from_ast(it.lookup_intern(db).ast_id, db),
+            AttrDefId::TraitId(it) => attrs_from_loc(it.lookup(db), db),
+            AttrDefId::MacroDefId(it) => {
+                it.ast_id.map_or_else(Default::default, |ast_id| attrs_from_ast(ast_id, db))
+            }
+            AttrDefId::ImplId(it) => attrs_from_loc(it.lookup(db), db),
             AttrDefId::ConstId(it) => attrs_from_loc(it.lookup(db), db),
             AttrDefId::StaticId(it) => attrs_from_loc(it.lookup(db), db),
             AttrDefId::FunctionId(it) => attrs_from_loc(it.lookup(db), db),
@@ -68,7 +71,7 @@ impl Attrs {
         }
     }
 
-    fn from_attrs_owner(db: &impl DefDatabase, owner: Source<&dyn AttrsOwner>) -> Attrs {
+    fn from_attrs_owner(db: &impl DefDatabase, owner: InFile<&dyn AttrsOwner>) -> Attrs {
         let hygiene = Hygiene::new(db, owner.file_id);
         Attrs::new(owner.value, &hygiene)
     }
@@ -91,7 +94,7 @@ impl Attrs {
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Attr {
-    pub(crate) path: Path,
+    pub(crate) path: ModPath,
     pub(crate) input: Option<AttrInput>,
 }
 
@@ -103,7 +106,7 @@ pub enum AttrInput {
 
 impl Attr {
     fn from_src(ast: ast::Attr, hygiene: &Hygiene) -> Option<Attr> {
-        let path = Path::from_src(ast.path()?, hygiene)?;
+        let path = ModPath::from_src(ast.path()?, hygiene)?;
         let input = match ast.input() {
             None => None,
             Some(ast::AttrInput::Literal(lit)) => {
@@ -157,7 +160,7 @@ where
     N: ast::AttrsOwner,
     D: DefDatabase,
 {
-    let src = Source::new(src.file_id(), src.to_node(db));
+    let src = InFile::new(src.file_id, src.to_node(db));
     Attrs::from_attrs_owner(db, src.as_ref().map(|it| it as &dyn AttrsOwner))
 }
 
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index a57a0176d..d3e4c50ae 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -3,58 +3,75 @@
 mod lower;
 pub mod scope;
 
-use std::{ops::Index, sync::Arc};
+use std::{mem, ops::Index, sync::Arc};
 
+use drop_bomb::DropBomb;
+use either::Either;
 use hir_expand::{
-    either::Either, hygiene::Hygiene, AstId, HirFileId, MacroDefId, MacroFileKind, Source,
+    ast_id_map::AstIdMap, hygiene::Hygiene, AstId, HirFileId, InFile, MacroCallKind, MacroDefId,
 };
 use ra_arena::{map::ArenaMap, Arena};
+use ra_prof::profile;
 use ra_syntax::{ast, AstNode, AstPtr};
 use rustc_hash::FxHashMap;
 
 use crate::{
     db::DefDatabase,
     expr::{Expr, ExprId, Pat, PatId},
+    item_scope::BuiltinShadowMode,
+    item_scope::ItemScope,
     nameres::CrateDefMap,
-    path::Path,
-    DefWithBodyId, HasModule, HasSource, Lookup, ModuleId,
+    path::{ModPath, Path},
+    src::HasSource,
+    DefWithBodyId, HasModule, Lookup, ModuleId,
 };
 
-struct Expander {
+pub(crate) struct Expander {
     crate_def_map: Arc<CrateDefMap>,
     current_file_id: HirFileId,
     hygiene: Hygiene,
+    ast_id_map: Arc<AstIdMap>,
     module: ModuleId,
 }
 
 impl Expander {
-    fn new(db: &impl DefDatabase, current_file_id: HirFileId, module: ModuleId) -> Expander {
+    pub(crate) fn new(
+        db: &impl DefDatabase,
+        current_file_id: HirFileId,
+        module: ModuleId,
+    ) -> Expander {
         let crate_def_map = db.crate_def_map(module.krate);
         let hygiene = Hygiene::new(db, current_file_id);
-        Expander { crate_def_map, current_file_id, hygiene, module }
+        let ast_id_map = db.ast_id_map(current_file_id);
+        Expander { crate_def_map, current_file_id, hygiene, ast_id_map, module }
     }
 
-    fn enter_expand(
+    pub(crate) fn enter_expand<T: ast::AstNode, DB: DefDatabase>(
         &mut self,
-        db: &impl DefDatabase,
+        db: &DB,
         macro_call: ast::MacroCall,
-    ) -> Option<(Mark, ast::Expr)> {
+    ) -> Option<(Mark, T)> {
         let ast_id = AstId::new(
             self.current_file_id,
             db.ast_id_map(self.current_file_id).ast_id(&macro_call),
         );
 
-        if let Some(path) = macro_call.path().and_then(|path| self.parse_path(path)) {
+        if let Some(path) = macro_call.path().and_then(|path| self.parse_mod_path(path)) {
             if let Some(def) = self.resolve_path_as_macro(db, &path) {
-                let call_id = def.as_call_id(db, ast_id);
-                let file_id = call_id.as_file(MacroFileKind::Expr);
+                let call_id = def.as_call_id(db, MacroCallKind::FnLike(ast_id));
+                let file_id = call_id.as_file();
                 if let Some(node) = db.parse_or_expand(file_id) {
-                    if let Some(expr) = ast::Expr::cast(node) {
+                    if let Some(expr) = T::cast(node) {
                         log::debug!("macro expansion {:#?}", expr.syntax());
 
-                        let mark = Mark { file_id: self.current_file_id };
+                        let mark = Mark {
+                            file_id: self.current_file_id,
+                            ast_id_map: mem::take(&mut self.ast_id_map),
+                            bomb: DropBomb::new("expansion mark dropped"),
+                        };
                         self.hygiene = Hygiene::new(db, file_id);
                         self.current_file_id = file_id;
+                        self.ast_id_map = db.ast_id_map(file_id);
 
                         return Some((mark, expr));
                     }
@@ -67,37 +84,44 @@ impl Expander {
         None
     }
 
-    fn exit(&mut self, db: &impl DefDatabase, mark: Mark) {
+    pub(crate) fn exit(&mut self, db: &impl DefDatabase, mut mark: Mark) {
         self.hygiene = Hygiene::new(db, mark.file_id);
         self.current_file_id = mark.file_id;
-        std::mem::forget(mark);
+        self.ast_id_map = mem::take(&mut mark.ast_id_map);
+        mark.bomb.defuse();
     }
 
-    fn to_source<T>(&self, value: T) -> Source<T> {
-        Source { file_id: self.current_file_id, value }
+    pub(crate) fn to_source<T>(&self, value: T) -> InFile<T> {
+        InFile { file_id: self.current_file_id, value }
     }
 
     fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
         Path::from_src(path, &self.hygiene)
     }
 
-    fn resolve_path_as_macro(&self, db: &impl DefDatabase, path: &Path) -> Option<MacroDefId> {
-        self.crate_def_map.resolve_path(db, self.module.local_id, path).0.take_macros()
+    fn parse_mod_path(&mut self, path: ast::Path) -> Option<ModPath> {
+        ModPath::from_src(path, &self.hygiene)
     }
-}
 
-struct Mark {
-    file_id: HirFileId,
-}
+    fn resolve_path_as_macro(&self, db: &impl DefDatabase, path: &ModPath) -> Option<MacroDefId> {
+        self.crate_def_map
+            .resolve_path(db, self.module.local_id, path, BuiltinShadowMode::Other)
+            .0
+            .take_macros()
+    }
 
-impl Drop for Mark {
-    fn drop(&mut self) {
-        if !std::thread::panicking() {
-            panic!("dropped mark")
-        }
+    fn ast_id<N: AstNode>(&self, item: &N) -> AstId<N> {
+        let file_local_id = self.ast_id_map.ast_id(item);
+        AstId::new(self.current_file_id, file_local_id)
     }
 }
 
+pub(crate) struct Mark {
+    file_id: HirFileId,
+    ast_id_map: Arc<AstIdMap>,
+    bomb: DropBomb,
+}
+
 /// The body of an item (function, const etc.).
 #[derive(Debug, Eq, PartialEq)]
 pub struct Body {
@@ -112,13 +136,14 @@ pub struct Body {
     pub params: Vec<PatId>,
     /// The `ExprId` of the actual body expression.
     pub body_expr: ExprId,
+    pub item_scope: ItemScope,
 }
 
 pub type ExprPtr = Either<AstPtr<ast::Expr>, AstPtr<ast::RecordField>>;
-pub type ExprSource = Source<ExprPtr>;
+pub type ExprSource = InFile<ExprPtr>;
 
 pub type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>;
-pub type PatSource = Source<PatPtr>;
+pub type PatSource = InFile<PatPtr>;
 
 /// An item body together with the mapping from syntax nodes to HIR expression
 /// IDs. This is needed to go from e.g. a position in a file to the HIR
@@ -145,6 +170,7 @@ impl Body {
         db: &impl DefDatabase,
         def: DefWithBodyId,
     ) -> (Arc<Body>, Arc<BodySourceMap>) {
+        let _p = profile("body_with_source_map_query");
         let mut params = None;
 
         let (file_id, module, body) = match def {
@@ -166,7 +192,7 @@ impl Body {
             }
         };
         let expander = Expander::new(db, file_id, module);
-        let (body, source_map) = Body::new(db, expander, params, body);
+        let (body, source_map) = Body::new(db, def, expander, params, body);
         (Arc::new(body), Arc::new(source_map))
     }
 
@@ -176,11 +202,12 @@ impl Body {
 
     fn new(
         db: &impl DefDatabase,
+        def: DefWithBodyId,
         expander: Expander,
         params: Option<ast::ParamList>,
         body: Option<ast::Expr>,
     ) -> (Body, BodySourceMap) {
-        lower::lower(db, expander, params, body)
+        lower::lower(db, def, expander, params, body)
     }
 }
 
@@ -205,8 +232,13 @@ impl BodySourceMap {
         self.expr_map_back.get(expr).copied()
     }
 
-    pub fn node_expr(&self, node: Source<&ast::Expr>) -> Option<ExprId> {
-        let src = node.map(|it| Either::A(AstPtr::new(it)));
+    pub fn node_expr(&self, node: InFile<&ast::Expr>) -> Option<ExprId> {
+        let src = node.map(|it| Either::Left(AstPtr::new(it)));
+        self.expr_map.get(&src).cloned()
+    }
+
+    pub fn field_init_shorthand_expr(&self, node: InFile<&ast::RecordField>) -> Option<ExprId> {
+        let src = node.map(|it| Either::Right(AstPtr::new(it)));
         self.expr_map.get(&src).cloned()
     }
 
@@ -214,8 +246,8 @@ impl BodySourceMap {
         self.pat_map_back.get(pat).copied()
     }
 
-    pub fn node_pat(&self, node: Source<&ast::Pat>) -> Option<PatId> {
-        let src = node.map(|it| Either::A(AstPtr::new(it)));
+    pub fn node_pat(&self, node: InFile<&ast::Pat>) -> Option<PatId> {
+        let src = node.map(|it| Either::Left(AstPtr::new(it)));
         self.pat_map.get(&src).cloned()
     }
 
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 331736cb2..5323af097 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -1,14 +1,13 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
 
-use hir_expand::{
-    either::Either,
-    name::{self, AsName, Name},
-};
+use either::Either;
+
+use hir_expand::name::{name, AsName, Name};
 use ra_arena::Arena;
 use ra_syntax::{
     ast::{
-        self, ArgListOwner, ArrayExprKind, LiteralKind, LoopBodyOwner, NameOwner,
+        self, ArgListOwner, ArrayExprKind, LiteralKind, LoopBodyOwner, ModuleItemOwner, NameOwner,
         TypeAscriptionOwner,
     },
     AstNode, AstPtr,
@@ -26,23 +25,28 @@ use crate::{
     path::GenericArgs,
     path::Path,
     type_ref::{Mutability, TypeRef},
+    ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern, ModuleDefId, StaticLoc,
+    StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
 pub(super) fn lower(
     db: &impl DefDatabase,
+    def: DefWithBodyId,
     expander: Expander,
     params: Option<ast::ParamList>,
     body: Option<ast::Expr>,
 ) -> (Body, BodySourceMap) {
     ExprCollector {
-        expander,
         db,
+        def,
+        expander,
         source_map: BodySourceMap::default(),
         body: Body {
             exprs: Arena::default(),
             pats: Arena::default(),
             params: Vec::new(),
             body_expr: ExprId::dummy(),
+            item_scope: Default::default(),
         },
     }
     .collect(params, body)
@@ -50,6 +54,7 @@ pub(super) fn lower(
 
 struct ExprCollector<DB> {
     db: DB,
+    def: DefWithBodyId,
     expander: Expander,
 
     body: Body,
@@ -70,11 +75,11 @@ where
                 let ptr = AstPtr::new(&self_param);
                 let param_pat = self.alloc_pat(
                     Pat::Bind {
-                        name: name::SELF_PARAM,
+                        name: name![self],
                         mode: BindingAnnotation::Unannotated,
                         subpat: None,
                     },
-                    Either::B(ptr),
+                    Either::Right(ptr),
                 );
                 self.body.params.push(param_pat);
             }
@@ -94,7 +99,7 @@ where
     }
 
     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
-        let ptr = Either::A(ptr);
+        let ptr = Either::Left(ptr);
         let id = self.body.exprs.alloc(expr);
         let src = self.expander.to_source(ptr);
         self.source_map.expr_map.insert(src, id);
@@ -107,7 +112,7 @@ where
         self.body.exprs.alloc(expr)
     }
     fn alloc_expr_field_shorthand(&mut self, expr: Expr, ptr: AstPtr<ast::RecordField>) -> ExprId {
-        let ptr = Either::B(ptr);
+        let ptr = Either::Right(ptr);
         let id = self.body.exprs.alloc(expr);
         let src = self.expander.to_source(ptr);
         self.source_map.expr_map.insert(src, id);
@@ -277,7 +282,7 @@ where
             ast::Expr::ParenExpr(e) => {
                 let inner = self.collect_expr_opt(e.expr());
                 // make the paren expr point to the inner expression as well
-                let src = self.expander.to_source(Either::A(syntax_ptr));
+                let src = self.expander.to_source(Either::Left(syntax_ptr));
                 self.source_map.expr_map.insert(src, inner);
                 inner
             }
@@ -367,8 +372,9 @@ where
                         arg_types.push(type_ref);
                     }
                 }
+                let ret_type = e.ret_type().and_then(|r| r.type_ref()).map(TypeRef::from_ast);
                 let body = self.collect_expr_opt(e.body());
-                self.alloc_expr(Expr::Lambda { args, arg_types, body }, syntax_ptr)
+                self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
             }
             ast::Expr::BinExpr(e) => {
                 let lhs = self.collect_expr_opt(e.lhs());
@@ -429,10 +435,17 @@ where
                 let index = self.collect_expr_opt(e.index());
                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
             }
-
-            // FIXME implement HIR for these:
-            ast::Expr::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::Expr::RangeExpr(e) => {
+                let lhs = e.start().map(|lhs| self.collect_expr(lhs));
+                let rhs = e.end().map(|rhs| self.collect_expr(rhs));
+                match e.op_kind() {
+                    Some(range_type) => {
+                        self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
+                    }
+                    None => self.alloc_expr(Expr::Missing, syntax_ptr),
+                }
+            }
+            // FIXME expand to statements in statement position
             ast::Expr::MacroCall(e) => match self.expander.enter_expand(self.db, e) {
                 Some((mark, expansion)) => {
                     let id = self.collect_expr(expansion);
@@ -441,6 +454,9 @@ where
                 }
                 None => self.alloc_expr(Expr::Missing, syntax_ptr),
             },
+
+            // FIXME implement HIR for these:
+            ast::Expr::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
         }
     }
 
@@ -458,6 +474,7 @@ where
             Some(block) => block,
             None => return self.alloc_expr(Expr::Missing, syntax_node_ptr),
         };
+        self.collect_block_items(&block);
         let statements = block
             .statements()
             .map(|s| match s {
@@ -474,6 +491,63 @@ where
         self.alloc_expr(Expr::Block { statements, tail }, syntax_node_ptr)
     }
 
+    fn collect_block_items(&mut self, block: &ast::Block) {
+        let container = ContainerId::DefWithBodyId(self.def);
+        for item in block.items() {
+            let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
+                ast::ModuleItem::FnDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (
+                        FunctionLoc { container: container.into(), ast_id }.intern(self.db).into(),
+                        def.name(),
+                    )
+                }
+                ast::ModuleItem::TypeAliasDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (
+                        TypeAliasLoc { container: container.into(), ast_id }.intern(self.db).into(),
+                        def.name(),
+                    )
+                }
+                ast::ModuleItem::ConstDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (
+                        ConstLoc { container: container.into(), ast_id }.intern(self.db).into(),
+                        def.name(),
+                    )
+                }
+                ast::ModuleItem::StaticDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (StaticLoc { container, ast_id }.intern(self.db).into(), def.name())
+                }
+                ast::ModuleItem::StructDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (StructLoc { container, ast_id }.intern(self.db).into(), def.name())
+                }
+                ast::ModuleItem::EnumDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (EnumLoc { container, ast_id }.intern(self.db).into(), def.name())
+                }
+                ast::ModuleItem::UnionDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (UnionLoc { container, ast_id }.intern(self.db).into(), def.name())
+                }
+                ast::ModuleItem::TraitDef(def) => {
+                    let ast_id = self.expander.ast_id(&def);
+                    (TraitLoc { container, ast_id }.intern(self.db).into(), def.name())
+                }
+                ast::ModuleItem::ImplBlock(_)
+                | ast::ModuleItem::UseItem(_)
+                | ast::ModuleItem::ExternCrateItem(_)
+                | ast::ModuleItem::Module(_) => continue,
+            };
+            self.body.item_scope.define_def(def);
+            if let Some(name) = name {
+                self.body.item_scope.push_res(name.as_name(), def.into());
+            }
+        }
+    }
+
     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
         if let Some(block) = expr {
             self.collect_block(block)
@@ -541,7 +615,7 @@ where
             ast::Pat::SlicePat(_) | ast::Pat::RangePat(_) => Pat::Missing,
         };
         let ptr = AstPtr::new(&pat);
-        self.alloc_pat(pattern, Either::A(ptr))
+        self.alloc_pat(pattern, Either::Left(ptr))
     }
 
     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
diff --git a/crates/ra_hir_def/src/body/scope.rs b/crates/ra_hir_def/src/body/scope.rs
index 625aa39dd..a63552327 100644
--- a/crates/ra_hir_def/src/body/scope.rs
+++ b/crates/ra_hir_def/src/body/scope.rs
@@ -171,7 +171,7 @@ fn compute_expr_scopes(expr: ExprId, body: &Body, scopes: &mut ExprScopes, scope
 
 #[cfg(test)]
 mod tests {
-    use hir_expand::{name::AsName, Source};
+    use hir_expand::{name::AsName, InFile};
     use ra_db::{fixture::WithFixture, FileId, SourceDatabase};
     use ra_syntax::{algo::find_node_at_offset, ast, AstNode};
     use test_utils::{assert_eq_text, covers, extract_offset};
@@ -183,8 +183,8 @@ mod tests {
         let crate_def_map = db.crate_def_map(krate);
 
         let module = crate_def_map.modules_for_file(file_id).next().unwrap();
-        let (_, res) = crate_def_map[module].scope.entries().next().unwrap();
-        match res.def.take_values().unwrap() {
+        let (_, def) = crate_def_map[module].scope.entries().next().unwrap();
+        match def.take_values().unwrap() {
             ModuleDefId::FunctionId(it) => it,
             _ => panic!(),
         }
@@ -211,7 +211,7 @@ mod tests {
         let (_body, source_map) = db.body_with_source_map(function.into());
 
         let expr_id = source_map
-            .node_expr(Source { file_id: file_id.into(), value: &marker.into() })
+            .node_expr(InFile { file_id: file_id.into(), value: &marker.into() })
             .unwrap();
         let scope = scopes.scope_for(expr_id);
 
@@ -318,7 +318,7 @@ mod tests {
         let expr_scope = {
             let expr_ast = name_ref.syntax().ancestors().find_map(ast::Expr::cast).unwrap();
             let expr_id =
-                source_map.node_expr(Source { file_id: file_id.into(), value: &expr_ast }).unwrap();
+                source_map.node_expr(InFile { file_id: file_id.into(), value: &expr_ast }).unwrap();
             scopes.scope_for(expr_id).unwrap()
         };
 
diff --git a/crates/ra_hir_def/src/builtin_type.rs b/crates/ra_hir_def/src/builtin_type.rs
index 5e8157144..d14901a9b 100644
--- a/crates/ra_hir_def/src/builtin_type.rs
+++ b/crates/ra_hir_def/src/builtin_type.rs
@@ -5,7 +5,7 @@
 
 use std::fmt;
 
-use hir_expand::name::{self, Name};
+use hir_expand::name::{name, Name};
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum Signedness {
@@ -52,26 +52,26 @@ pub enum BuiltinType {
 impl BuiltinType {
     #[rustfmt::skip]
     pub const ALL: &'static [(Name, BuiltinType)] = &[
-        (name::CHAR, BuiltinType::Char),
-        (name::BOOL, BuiltinType::Bool),
-        (name::STR,  BuiltinType::Str ),
-
-        (name::ISIZE, BuiltinType::Int(BuiltinInt::ISIZE)),
-        (name::I8,    BuiltinType::Int(BuiltinInt::I8)),
-        (name::I16,   BuiltinType::Int(BuiltinInt::I16)),
-        (name::I32,   BuiltinType::Int(BuiltinInt::I32)),
-        (name::I64,   BuiltinType::Int(BuiltinInt::I64)),
-        (name::I128,  BuiltinType::Int(BuiltinInt::I128)),
-
-        (name::USIZE, BuiltinType::Int(BuiltinInt::USIZE)),
-        (name::U8,    BuiltinType::Int(BuiltinInt::U8)),
-        (name::U16,   BuiltinType::Int(BuiltinInt::U16)),
-        (name::U32,   BuiltinType::Int(BuiltinInt::U32)),
-        (name::U64,   BuiltinType::Int(BuiltinInt::U64)),
-        (name::U128,  BuiltinType::Int(BuiltinInt::U128)),
-
-        (name::F32, BuiltinType::Float(BuiltinFloat::F32)),
-        (name::F64, BuiltinType::Float(BuiltinFloat::F64)),
+        (name![char], BuiltinType::Char),
+        (name![bool], BuiltinType::Bool),
+        (name![str],  BuiltinType::Str),
+
+        (name![isize], BuiltinType::Int(BuiltinInt::ISIZE)),
+        (name![i8],    BuiltinType::Int(BuiltinInt::I8)),
+        (name![i16],   BuiltinType::Int(BuiltinInt::I16)),
+        (name![i32],   BuiltinType::Int(BuiltinInt::I32)),
+        (name![i64],   BuiltinType::Int(BuiltinInt::I64)),
+        (name![i128],  BuiltinType::Int(BuiltinInt::I128)),
+
+        (name![usize], BuiltinType::Int(BuiltinInt::USIZE)),
+        (name![u8],    BuiltinType::Int(BuiltinInt::U8)),
+        (name![u16],   BuiltinType::Int(BuiltinInt::U16)),
+        (name![u32],   BuiltinType::Int(BuiltinInt::U32)),
+        (name![u64],   BuiltinType::Int(BuiltinInt::U64)),
+        (name![u128],  BuiltinType::Int(BuiltinInt::U128)),
+
+        (name![f32], BuiltinType::Float(BuiltinFloat::F32)),
+        (name![f64], BuiltinType::Float(BuiltinFloat::F64)),
     ];
 }
 
diff --git a/crates/ra_hir_def/src/child_by_source.rs b/crates/ra_hir_def/src/child_by_source.rs
new file mode 100644
index 000000000..8b6c773ee
--- /dev/null
+++ b/crates/ra_hir_def/src/child_by_source.rs
@@ -0,0 +1,177 @@
+//! When *constructing* `hir`, we start at some parent syntax node and recursively
+//! lower the children.
+//!
+//! This modules allows one to go in the opposite direction: start with a syntax
+//! node for a *child*, and get its hir.
+
+use either::Either;
+
+use crate::{
+    db::DefDatabase,
+    dyn_map::DynMap,
+    item_scope::ItemScope,
+    keys,
+    src::{HasChildSource, HasSource},
+    AdtId, AssocItemId, DefWithBodyId, EnumId, EnumVariantId, ImplId, Lookup, ModuleDefId,
+    ModuleId, StructFieldId, TraitId, VariantId,
+};
+
+pub trait ChildBySource {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap;
+}
+
+impl ChildBySource for TraitId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+
+        let data = db.trait_data(*self);
+        for (_name, item) in data.items.iter() {
+            match *item {
+                AssocItemId::FunctionId(func) => {
+                    let src = func.lookup(db).source(db);
+                    res[keys::FUNCTION].insert(src, func)
+                }
+                AssocItemId::ConstId(konst) => {
+                    let src = konst.lookup(db).source(db);
+                    res[keys::CONST].insert(src, konst)
+                }
+                AssocItemId::TypeAliasId(ty) => {
+                    let src = ty.lookup(db).source(db);
+                    res[keys::TYPE_ALIAS].insert(src, ty)
+                }
+            }
+        }
+
+        res
+    }
+}
+
+impl ChildBySource for ImplId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+
+        let data = db.impl_data(*self);
+        for &item in data.items.iter() {
+            match item {
+                AssocItemId::FunctionId(func) => {
+                    let src = func.lookup(db).source(db);
+                    res[keys::FUNCTION].insert(src, func)
+                }
+                AssocItemId::ConstId(konst) => {
+                    let src = konst.lookup(db).source(db);
+                    res[keys::CONST].insert(src, konst)
+                }
+                AssocItemId::TypeAliasId(ty) => {
+                    let src = ty.lookup(db).source(db);
+                    res[keys::TYPE_ALIAS].insert(src, ty)
+                }
+            }
+        }
+
+        res
+    }
+}
+
+impl ChildBySource for ModuleId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let crate_def_map = db.crate_def_map(self.krate);
+        let module_data = &crate_def_map[self.local_id];
+        module_data.scope.child_by_source(db)
+    }
+}
+
+impl ChildBySource for ItemScope {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+        self.declarations().for_each(|item| add_module_def(db, &mut res, item));
+        self.impls().for_each(|imp| add_impl(db, &mut res, imp));
+        return res;
+
+        fn add_module_def(db: &impl DefDatabase, map: &mut DynMap, item: ModuleDefId) {
+            match item {
+                ModuleDefId::FunctionId(func) => {
+                    let src = func.lookup(db).source(db);
+                    map[keys::FUNCTION].insert(src, func)
+                }
+                ModuleDefId::ConstId(konst) => {
+                    let src = konst.lookup(db).source(db);
+                    map[keys::CONST].insert(src, konst)
+                }
+                ModuleDefId::StaticId(statik) => {
+                    let src = statik.lookup(db).source(db);
+                    map[keys::STATIC].insert(src, statik)
+                }
+                ModuleDefId::TypeAliasId(ty) => {
+                    let src = ty.lookup(db).source(db);
+                    map[keys::TYPE_ALIAS].insert(src, ty)
+                }
+                ModuleDefId::TraitId(trait_) => {
+                    let src = trait_.lookup(db).source(db);
+                    map[keys::TRAIT].insert(src, trait_)
+                }
+                ModuleDefId::AdtId(adt) => match adt {
+                    AdtId::StructId(strukt) => {
+                        let src = strukt.lookup(db).source(db);
+                        map[keys::STRUCT].insert(src, strukt)
+                    }
+                    AdtId::UnionId(union_) => {
+                        let src = union_.lookup(db).source(db);
+                        map[keys::UNION].insert(src, union_)
+                    }
+                    AdtId::EnumId(enum_) => {
+                        let src = enum_.lookup(db).source(db);
+                        map[keys::ENUM].insert(src, enum_)
+                    }
+                },
+                _ => (),
+            }
+        }
+        fn add_impl(db: &impl DefDatabase, map: &mut DynMap, imp: ImplId) {
+            let src = imp.lookup(db).source(db);
+            map[keys::IMPL].insert(src, imp)
+        }
+    }
+}
+
+impl ChildBySource for VariantId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+
+        let arena_map = self.child_source(db);
+        let arena_map = arena_map.as_ref();
+        for (local_id, source) in arena_map.value.iter() {
+            let id = StructFieldId { parent: *self, local_id };
+            match source {
+                Either::Left(source) => {
+                    res[keys::TUPLE_FIELD].insert(arena_map.with_value(source.clone()), id)
+                }
+                Either::Right(source) => {
+                    res[keys::RECORD_FIELD].insert(arena_map.with_value(source.clone()), id)
+                }
+            }
+        }
+        res
+    }
+}
+
+impl ChildBySource for EnumId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+
+        let arena_map = self.child_source(db);
+        let arena_map = arena_map.as_ref();
+        for (local_id, source) in arena_map.value.iter() {
+            let id = EnumVariantId { parent: *self, local_id };
+            res[keys::ENUM_VARIANT].insert(arena_map.with_value(source.clone()), id)
+        }
+
+        res
+    }
+}
+
+impl ChildBySource for DefWithBodyId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let body = db.body(*self);
+        body.item_scope.child_by_source(db)
+    }
+}
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index fee10b237..1aa9a9b7d 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -3,16 +3,17 @@
 use std::sync::Arc;
 
 use hir_expand::{
-    name::{self, AsName, Name},
-    AstId,
+    name::{name, AsName, Name},
+    AstId, InFile,
 };
-use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
+use ra_syntax::ast::{self, AstNode, ImplItem, ModuleItemOwner, NameOwner, TypeAscriptionOwner};
 
 use crate::{
     db::DefDatabase,
+    src::HasSource,
     type_ref::{Mutability, TypeRef},
-    AssocItemId, AstItemDef, ConstId, ConstLoc, ContainerId, FunctionId, FunctionLoc, HasSource,
-    ImplId, Intern, Lookup, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
+    AssocContainerId, AssocItemId, ConstId, ConstLoc, Expander, FunctionId, FunctionLoc, HasModule,
+    ImplId, Intern, Lookup, ModuleId, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -36,7 +37,7 @@ impl FunctionData {
                 let self_type = if let Some(type_ref) = self_param.ascribed_type() {
                     TypeRef::from_ast(type_ref)
                 } else {
-                    let self_type = TypeRef::Path(name::SELF_TYPE.into());
+                    let self_type = TypeRef::Path(name![Self].into());
                     match self_param.kind() {
                         ast::SelfParamKind::Owned => self_type,
                         ast::SelfParamKind::Ref => {
@@ -93,12 +94,12 @@ pub struct TraitData {
 
 impl TraitData {
     pub(crate) fn trait_data_query(db: &impl DefDatabase, tr: TraitId) -> Arc<TraitData> {
-        let src = tr.source(db);
+        let src = tr.lookup(db).source(db);
         let name = src.value.name().map_or_else(Name::missing, |n| n.as_name());
         let auto = src.value.is_auto();
         let ast_id_map = db.ast_id_map(src.file_id);
 
-        let container = ContainerId::TraitId(tr);
+        let container = AssocContainerId::TraitId(tr);
         let items = if let Some(item_list) = src.value.item_list() {
             item_list
                 .impl_items()
@@ -166,46 +167,24 @@ pub struct ImplData {
 
 impl ImplData {
     pub(crate) fn impl_data_query(db: &impl DefDatabase, id: ImplId) -> Arc<ImplData> {
-        let src = id.source(db);
-        let items = db.ast_id_map(src.file_id);
+        let impl_loc = id.lookup(db);
+        let src = impl_loc.source(db);
 
         let target_trait = src.value.target_trait().map(TypeRef::from_ast);
         let target_type = TypeRef::from_ast_opt(src.value.target_type());
         let is_negative = src.value.is_negative();
+        let module_id = impl_loc.container.module(db);
 
-        let items = if let Some(item_list) = src.value.item_list() {
-            item_list
-                .impl_items()
-                .map(|item_node| match item_node {
-                    ast::ImplItem::FnDef(it) => {
-                        let def = FunctionLoc {
-                            container: ContainerId::ImplId(id),
-                            ast_id: AstId::new(src.file_id, items.ast_id(&it)),
-                        }
-                        .intern(db);
-                        def.into()
-                    }
-                    ast::ImplItem::ConstDef(it) => {
-                        let def = ConstLoc {
-                            container: ContainerId::ImplId(id),
-                            ast_id: AstId::new(src.file_id, items.ast_id(&it)),
-                        }
-                        .intern(db);
-                        def.into()
-                    }
-                    ast::ImplItem::TypeAliasDef(it) => {
-                        let def = TypeAliasLoc {
-                            container: ContainerId::ImplId(id),
-                            ast_id: AstId::new(src.file_id, items.ast_id(&it)),
-                        }
-                        .intern(db);
-                        def.into()
-                    }
-                })
-                .collect()
-        } else {
-            Vec::new()
-        };
+        let mut items = Vec::new();
+        if let Some(item_list) = src.value.item_list() {
+            items.extend(collect_impl_items(db, item_list.impl_items(), src.file_id, id));
+            items.extend(collect_impl_items_in_macros(
+                db,
+                module_id,
+                &src.with_value(item_list),
+                id,
+            ));
+        }
 
         let res = ImplData { target_trait, target_type, items, is_negative };
         Arc::new(res)
@@ -236,3 +215,92 @@ impl ConstData {
         ConstData { name, type_ref }
     }
 }
+
+fn collect_impl_items_in_macros(
+    db: &impl DefDatabase,
+    module_id: ModuleId,
+    impl_block: &InFile<ast::ItemList>,
+    id: ImplId,
+) -> Vec<AssocItemId> {
+    let mut expander = Expander::new(db, impl_block.file_id, module_id);
+    let mut res = Vec::new();
+
+    // We set a limit to protect against infinite recursion
+    let limit = 100;
+
+    for m in impl_block.value.syntax().children().filter_map(ast::MacroCall::cast) {
+        res.extend(collect_impl_items_in_macro(db, &mut expander, m, id, limit))
+    }
+
+    res
+}
+
+fn collect_impl_items_in_macro(
+    db: &impl DefDatabase,
+    expander: &mut Expander,
+    m: ast::MacroCall,
+    id: ImplId,
+    limit: usize,
+) -> Vec<AssocItemId> {
+    if limit == 0 {
+        return Vec::new();
+    }
+
+    if let Some((mark, items)) = expander.enter_expand(db, m) {
+        let items: InFile<ast::MacroItems> = expander.to_source(items);
+        let mut res = collect_impl_items(
+            db,
+            items.value.items().filter_map(|it| ImplItem::cast(it.syntax().clone())),
+            items.file_id,
+            id,
+        );
+        // Recursive collect macros
+        // Note that ast::ModuleItem do not include ast::MacroCall
+        // We cannot use ModuleItemOwner::items here
+        for it in items.value.syntax().children().filter_map(ast::MacroCall::cast) {
+            res.extend(collect_impl_items_in_macro(db, expander, it, id, limit - 1))
+        }
+        expander.exit(db, mark);
+        res
+    } else {
+        Vec::new()
+    }
+}
+
+fn collect_impl_items(
+    db: &impl DefDatabase,
+    impl_items: impl Iterator<Item = ImplItem>,
+    file_id: crate::HirFileId,
+    id: ImplId,
+) -> Vec<AssocItemId> {
+    let items = db.ast_id_map(file_id);
+
+    impl_items
+        .map(|item_node| match item_node {
+            ast::ImplItem::FnDef(it) => {
+                let def = FunctionLoc {
+                    container: AssocContainerId::ImplId(id),
+                    ast_id: AstId::new(file_id, items.ast_id(&it)),
+                }
+                .intern(db);
+                def.into()
+            }
+            ast::ImplItem::ConstDef(it) => {
+                let def = ConstLoc {
+                    container: AssocContainerId::ImplId(id),
+                    ast_id: AstId::new(file_id, items.ast_id(&it)),
+                }
+                .intern(db);
+                def.into()
+            }
+            ast::ImplItem::TypeAliasDef(it) => {
+                let def = TypeAliasLoc {
+                    container: AssocContainerId::ImplId(id),
+                    ast_id: AstId::new(file_id, items.ast_id(&it)),
+                }
+                .intern(db);
+                def.into()
+            }
+        })
+        .collect()
+}
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index ef5611ffc..c55fd4111 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 
 use hir_expand::{db::AstDatabase, HirFileId};
 use ra_db::{salsa, CrateId, SourceDatabase};
-use ra_syntax::{ast, SmolStr};
+use ra_syntax::SmolStr;
 
 use crate::{
     adt::{EnumData, StructData},
@@ -13,13 +13,10 @@ use crate::{
     docs::Documentation,
     generics::GenericParams,
     lang_item::{LangItemTarget, LangItems},
-    nameres::{
-        raw::{ImportSourceMap, RawItems},
-        CrateDefMap,
-    },
-    AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, FunctionId, FunctionLoc, GenericDefId,
-    ImplId, ItemLoc, ModuleId, StaticId, StaticLoc, StructId, TraitId, TypeAliasId, TypeAliasLoc,
-    UnionId,
+    nameres::{raw::RawItems, CrateDefMap},
+    AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, EnumLoc, FunctionId, FunctionLoc,
+    GenericDefId, ImplId, ImplLoc, ModuleId, StaticId, StaticLoc, StructId, StructLoc, TraitId,
+    TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc,
 };
 
 #[salsa::query_group(InternDatabaseStorage)]
@@ -27,31 +24,25 @@ pub trait InternDatabase: SourceDatabase {
     #[salsa::interned]
     fn intern_function(&self, loc: FunctionLoc) -> FunctionId;
     #[salsa::interned]
-    fn intern_struct(&self, loc: ItemLoc<ast::StructDef>) -> StructId;
+    fn intern_struct(&self, loc: StructLoc) -> StructId;
     #[salsa::interned]
-    fn intern_union(&self, loc: ItemLoc<ast::UnionDef>) -> UnionId;
+    fn intern_union(&self, loc: UnionLoc) -> UnionId;
     #[salsa::interned]
-    fn intern_enum(&self, loc: ItemLoc<ast::EnumDef>) -> EnumId;
+    fn intern_enum(&self, loc: EnumLoc) -> EnumId;
     #[salsa::interned]
     fn intern_const(&self, loc: ConstLoc) -> ConstId;
     #[salsa::interned]
     fn intern_static(&self, loc: StaticLoc) -> StaticId;
     #[salsa::interned]
-    fn intern_trait(&self, loc: ItemLoc<ast::TraitDef>) -> TraitId;
+    fn intern_trait(&self, loc: TraitLoc) -> TraitId;
     #[salsa::interned]
     fn intern_type_alias(&self, loc: TypeAliasLoc) -> TypeAliasId;
     #[salsa::interned]
-    fn intern_impl(&self, loc: ItemLoc<ast::ImplBlock>) -> ImplId;
+    fn intern_impl(&self, loc: ImplLoc) -> ImplId;
 }
 
 #[salsa::query_group(DefDatabaseStorage)]
 pub trait DefDatabase: InternDatabase + AstDatabase {
-    #[salsa::invoke(RawItems::raw_items_with_source_map_query)]
-    fn raw_items_with_source_map(
-        &self,
-        file_id: HirFileId,
-    ) -> (Arc<RawItems>, Arc<ImportSourceMap>);
-
     #[salsa::invoke(RawItems::raw_items_query)]
     fn raw_items(&self, file_id: HirFileId) -> Arc<RawItems>;
 
diff --git a/crates/ra_hir_def/src/diagnostics.rs b/crates/ra_hir_def/src/diagnostics.rs
index eda9b2269..095498429 100644
--- a/crates/ra_hir_def/src/diagnostics.rs
+++ b/crates/ra_hir_def/src/diagnostics.rs
@@ -6,7 +6,7 @@ use hir_expand::diagnostics::Diagnostic;
 use ra_db::RelativePathBuf;
 use ra_syntax::{ast, AstPtr, SyntaxNodePtr};
 
-use hir_expand::{HirFileId, Source};
+use hir_expand::{HirFileId, InFile};
 
 #[derive(Debug)]
 pub struct UnresolvedModule {
@@ -19,8 +19,8 @@ impl Diagnostic for UnresolvedModule {
     fn message(&self) -> String {
         "unresolved module".to_string()
     }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.decl.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.decl.into() }
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
diff --git a/crates/ra_hir_def/src/docs.rs b/crates/ra_hir_def/src/docs.rs
index 34ed9b7a5..b29f142e3 100644
--- a/crates/ra_hir_def/src/docs.rs
+++ b/crates/ra_hir_def/src/docs.rs
@@ -5,10 +5,14 @@
 
 use std::sync::Arc;
 
-use hir_expand::either::Either;
+use either::Either;
 use ra_syntax::ast;
 
-use crate::{db::DefDatabase, AdtId, AstItemDef, AttrDefId, HasChildSource, HasSource, Lookup};
+use crate::{
+    db::DefDatabase,
+    src::{HasChildSource, HasSource},
+    AdtId, AttrDefId, Lookup,
+};
 
 /// Holds documentation
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -42,21 +46,21 @@ impl Documentation {
             AttrDefId::StructFieldId(it) => {
                 let src = it.parent.child_source(db);
                 match &src.value[it.local_id] {
-                    Either::A(_tuple) => None,
-                    Either::B(record) => docs_from_ast(record),
+                    Either::Left(_tuple) => None,
+                    Either::Right(record) => docs_from_ast(record),
                 }
             }
             AttrDefId::AdtId(it) => match it {
-                AdtId::StructId(it) => docs_from_ast(&it.source(db).value),
-                AdtId::EnumId(it) => docs_from_ast(&it.source(db).value),
-                AdtId::UnionId(it) => docs_from_ast(&it.source(db).value),
+                AdtId::StructId(it) => docs_from_ast(&it.lookup(db).source(db).value),
+                AdtId::EnumId(it) => docs_from_ast(&it.lookup(db).source(db).value),
+                AdtId::UnionId(it) => docs_from_ast(&it.lookup(db).source(db).value),
             },
             AttrDefId::EnumVariantId(it) => {
                 let src = it.parent.child_source(db);
                 docs_from_ast(&src.value[it.local_id])
             }
-            AttrDefId::TraitId(it) => docs_from_ast(&it.source(db).value),
-            AttrDefId::MacroDefId(it) => docs_from_ast(&it.ast_id.to_node(db)),
+            AttrDefId::TraitId(it) => docs_from_ast(&it.lookup(db).source(db).value),
+            AttrDefId::MacroDefId(it) => docs_from_ast(&it.ast_id?.to_node(db)),
             AttrDefId::ConstId(it) => docs_from_ast(&it.lookup(db).source(db).value),
             AttrDefId::StaticId(it) => docs_from_ast(&it.lookup(db).source(db).value),
             AttrDefId::FunctionId(it) => docs_from_ast(&it.lookup(db).source(db).value),
diff --git a/crates/ra_hir_def/src/dyn_map.rs b/crates/ra_hir_def/src/dyn_map.rs
new file mode 100644
index 000000000..6f269d7b0
--- /dev/null
+++ b/crates/ra_hir_def/src/dyn_map.rs
@@ -0,0 +1,108 @@
+//! This module defines a `DynMap` -- a container for heterogeneous maps.
+//!
+//! This means that `DynMap` stores a bunch of hash maps inside, and those maps
+//! can be of different types.
+//!
+//! It is used like this:
+//!
+//! ```
+//! // keys define submaps of a `DynMap`
+//! const STRING_TO_U32: Key<String, u32> = Key::new();
+//! const U32_TO_VEC: Key<u32, Vec<bool>> = Key::new();
+//!
+//! // Note: concrete type, no type params!
+//! let mut map = DynMap::new();
+//!
+//! // To access a specific map, index the `DynMap` by `Key`:
+//! map[STRING_TO_U32].insert("hello".to_string(), 92);
+//! let value = map[U32_TO_VEC].get(92);
+//! assert!(value.is_none());
+//! ```
+//!
+//! This is a work of fiction. Any similarities to Kotlin's `BindingContext` are
+//! a coincidence.
+use std::{
+    hash::Hash,
+    marker::PhantomData,
+    ops::{Index, IndexMut},
+};
+
+use anymap::Map;
+use rustc_hash::FxHashMap;
+
+pub struct Key<K, V, P = (K, V)> {
+    _phantom: PhantomData<(K, V, P)>,
+}
+
+impl<K, V, P> Key<K, V, P> {
+    pub(crate) const fn new() -> Key<K, V, P> {
+        Key { _phantom: PhantomData }
+    }
+}
+
+impl<K, V, P> Copy for Key<K, V, P> {}
+
+impl<K, V, P> Clone for Key<K, V, P> {
+    fn clone(&self) -> Key<K, V, P> {
+        *self
+    }
+}
+
+pub trait Policy {
+    type K;
+    type V;
+
+    fn insert(map: &mut DynMap, key: Self::K, value: Self::V);
+    fn get<'a>(map: &'a DynMap, key: &Self::K) -> Option<&'a Self::V>;
+}
+
+impl<K: Hash + Eq + 'static, V: 'static> Policy for (K, V) {
+    type K = K;
+    type V = V;
+    fn insert(map: &mut DynMap, key: K, value: V) {
+        map.map.entry::<FxHashMap<K, V>>().or_insert_with(Default::default).insert(key, value);
+    }
+    fn get<'a>(map: &'a DynMap, key: &K) -> Option<&'a V> {
+        map.map.get::<FxHashMap<K, V>>()?.get(key)
+    }
+}
+
+pub struct DynMap {
+    pub(crate) map: Map,
+}
+
+impl Default for DynMap {
+    fn default() -> Self {
+        DynMap { map: Map::new() }
+    }
+}
+
+#[repr(transparent)]
+pub struct KeyMap<KEY> {
+    map: DynMap,
+    _phantom: PhantomData<KEY>,
+}
+
+impl<P: Policy> KeyMap<Key<P::K, P::V, P>> {
+    pub fn insert(&mut self, key: P::K, value: P::V) {
+        P::insert(&mut self.map, key, value)
+    }
+    pub fn get(&self, key: &P::K) -> Option<&P::V> {
+        P::get(&self.map, key)
+    }
+}
+
+impl<P: Policy> Index<Key<P::K, P::V, P>> for DynMap {
+    type Output = KeyMap<Key<P::K, P::V, P>>;
+    fn index(&self, _key: Key<P::K, P::V, P>) -> &Self::Output {
+        // Safe due to `#[repr(transparent)]`.
+        unsafe { std::mem::transmute::<&DynMap, &KeyMap<Key<P::K, P::V, P>>>(self) }
+    }
+}
+
+impl<P: Policy> IndexMut<Key<P::K, P::V, P>> for DynMap {
+    fn index_mut(&mut self, _key: Key<P::K, P::V, P>) -> &mut Self::Output {
+        // Safe due to `#[repr(transparent)]`.
+        unsafe { std::mem::transmute::<&mut DynMap, &mut KeyMap<Key<P::K, P::V, P>>>(self) }
+    }
+}
diff --git a/crates/ra_hir_def/src/expr.rs b/crates/ra_hir_def/src/expr.rs
index 04c1d8f69..a75ef9970 100644
--- a/crates/ra_hir_def/src/expr.rs
+++ b/crates/ra_hir_def/src/expr.rs
@@ -14,6 +14,7 @@
 
 use hir_expand::name::Name;
 use ra_arena::{impl_arena_id, RawId};
+use ra_syntax::ast::RangeOp;
 
 use crate::{
     builtin_type::{BuiltinFloat, BuiltinInt},
@@ -130,6 +131,11 @@ pub enum Expr {
         rhs: ExprId,
         op: Option<BinaryOp>,
     },
+    Range {
+        lhs: Option<ExprId>,
+        rhs: Option<ExprId>,
+        range_type: RangeOp,
+    },
     Index {
         base: ExprId,
         index: ExprId,
@@ -137,6 +143,7 @@ pub enum Expr {
     Lambda {
         args: Vec<PatId>,
         arg_types: Vec<Option<TypeRef>>,
+        ret_type: Option<TypeRef>,
         body: ExprId,
     },
     Tuple {
@@ -288,6 +295,14 @@ impl Expr {
                 f(*lhs);
                 f(*rhs);
             }
+            Expr::Range { lhs, rhs, .. } => {
+                if let Some(lhs) = rhs {
+                    f(*lhs);
+                }
+                if let Some(rhs) = lhs {
+                    f(*rhs);
+                }
+            }
             Expr::Index { base, index } => {
                 f(*base);
                 f(*index);
diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs
index 3f94e40e4..e9c28c730 100644
--- a/crates/ra_hir_def/src/generics.rs
+++ b/crates/ra_hir_def/src/generics.rs
@@ -4,20 +4,29 @@
 //! in rustc.
 use std::sync::Arc;
 
-use hir_expand::name::{self, AsName, Name};
+use either::Either;
+use hir_expand::{
+    name::{name, AsName, Name},
+    InFile,
+};
+use ra_arena::{map::ArenaMap, Arena};
+use ra_db::FileId;
 use ra_syntax::ast::{self, NameOwner, TypeBoundsOwner, TypeParamsOwner};
 
 use crate::{
+    child_by_source::ChildBySource,
     db::DefDatabase,
+    dyn_map::DynMap,
+    keys,
+    src::HasChildSource,
+    src::HasSource,
     type_ref::{TypeBound, TypeRef},
-    AdtId, AstItemDef, ContainerId, GenericDefId, HasSource, Lookup,
+    AdtId, GenericDefId, LocalTypeParamId, Lookup, TypeParamId,
 };
 
 /// Data about a generic parameter (to a function, struct, impl, ...).
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct GenericParam {
-    // FIXME: give generic params proper IDs
-    pub idx: u32,
+pub struct TypeParamData {
     pub name: Name,
     pub default: Option<TypeRef>,
 }
@@ -25,8 +34,8 @@ pub struct GenericParam {
 /// Data about the generic parameters of a function, struct, impl, etc.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct GenericParams {
-    pub parent_params: Option<Arc<GenericParams>>,
-    pub params: Vec<GenericParam>,
+    pub types: Arena<LocalTypeParamId, TypeParamData>,
+    // lifetimes: Arena<LocalLifetimeParamId, LifetimeParamData>,
     pub where_predicates: Vec<WherePredicate>,
 }
 
@@ -40,63 +49,87 @@ pub struct WherePredicate {
     pub bound: TypeBound,
 }
 
+type SourceMap = ArenaMap<LocalTypeParamId, Either<ast::TraitDef, ast::TypeParam>>;
+
 impl GenericParams {
     pub(crate) fn generic_params_query(
         db: &impl DefDatabase,
         def: GenericDefId,
     ) -> Arc<GenericParams> {
-        let parent_generics = parent_generic_def(db, def).map(|it| db.generic_params(it));
-        Arc::new(GenericParams::new(db, def.into(), parent_generics))
+        let (params, _source_map) = GenericParams::new(db, def.into());
+        Arc::new(params)
     }
 
-    fn new(
-        db: &impl DefDatabase,
-        def: GenericDefId,
-        parent_params: Option<Arc<GenericParams>>,
-    ) -> GenericParams {
-        let mut generics =
-            GenericParams { params: Vec::new(), parent_params, where_predicates: Vec::new() };
-        let start = generics.parent_params.as_ref().map(|p| p.params.len()).unwrap_or(0) as u32;
+    fn new(db: &impl DefDatabase, def: GenericDefId) -> (GenericParams, InFile<SourceMap>) {
+        let mut generics = GenericParams { types: Arena::default(), where_predicates: Vec::new() };
+        let mut sm = ArenaMap::default();
         // FIXME: add `: Sized` bound for everything except for `Self` in traits
-        match def {
-            GenericDefId::FunctionId(it) => generics.fill(&it.lookup(db).source(db).value, start),
-            GenericDefId::AdtId(AdtId::StructId(it)) => generics.fill(&it.source(db).value, start),
-            GenericDefId::AdtId(AdtId::UnionId(it)) => generics.fill(&it.source(db).value, start),
-            GenericDefId::AdtId(AdtId::EnumId(it)) => generics.fill(&it.source(db).value, start),
+        let file_id = match def {
+            GenericDefId::FunctionId(it) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
+            GenericDefId::AdtId(AdtId::StructId(it)) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
+            GenericDefId::AdtId(AdtId::UnionId(it)) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
+            GenericDefId::AdtId(AdtId::EnumId(it)) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
             GenericDefId::TraitId(it) => {
+                let src = it.lookup(db).source(db);
+
                 // traits get the Self type as an implicit first type parameter
-                generics.params.push(GenericParam {
-                    idx: start,
-                    name: name::SELF_TYPE,
-                    default: None,
-                });
-                generics.fill(&it.source(db).value, start + 1);
+                let self_param_id =
+                    generics.types.alloc(TypeParamData { name: name![Self], default: None });
+                sm.insert(self_param_id, Either::Left(src.value.clone()));
                 // add super traits as bounds on Self
                 // i.e., trait Foo: Bar is equivalent to trait Foo where Self: Bar
-                let self_param = TypeRef::Path(name::SELF_TYPE.into());
-                generics.fill_bounds(&it.source(db).value, self_param);
+                let self_param = TypeRef::Path(name![Self].into());
+                generics.fill_bounds(&src.value, self_param);
+
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
+            GenericDefId::TypeAliasId(it) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
             }
-            GenericDefId::TypeAliasId(it) => generics.fill(&it.lookup(db).source(db).value, start),
             // Note that we don't add `Self` here: in `impl`s, `Self` is not a
             // type-parameter, but rather is a type-alias for impl's target
             // type, so this is handled by the resolver.
-            GenericDefId::ImplId(it) => generics.fill(&it.source(db).value, start),
-            GenericDefId::EnumVariantId(_) | GenericDefId::ConstId(_) => {}
-        }
+            GenericDefId::ImplId(it) => {
+                let src = it.lookup(db).source(db);
+                generics.fill(&mut sm, &src.value);
+                src.file_id
+            }
+            // We won't be using this ID anyway
+            GenericDefId::EnumVariantId(_) | GenericDefId::ConstId(_) => FileId(!0).into(),
+        };
 
-        generics
+        (generics, InFile::new(file_id, sm))
     }
 
-    fn fill(&mut self, node: &impl TypeParamsOwner, start: u32) {
+    fn fill(&mut self, sm: &mut SourceMap, node: &dyn TypeParamsOwner) {
         if let Some(params) = node.type_param_list() {
-            self.fill_params(params, start)
+            self.fill_params(sm, params)
         }
         if let Some(where_clause) = node.where_clause() {
             self.fill_where_predicates(where_clause);
         }
     }
 
-    fn fill_bounds(&mut self, node: &impl ast::TypeBoundsOwner, type_ref: TypeRef) {
+    fn fill_bounds(&mut self, node: &dyn ast::TypeBoundsOwner, type_ref: TypeRef) {
         for bound in
             node.type_bound_list().iter().flat_map(|type_bound_list| type_bound_list.bounds())
         {
@@ -104,13 +137,14 @@ impl GenericParams {
         }
     }
 
-    fn fill_params(&mut self, params: ast::TypeParamList, start: u32) {
-        for (idx, type_param) in params.type_params().enumerate() {
+    fn fill_params(&mut self, sm: &mut SourceMap, params: ast::TypeParamList) {
+        for type_param in params.type_params() {
             let name = type_param.name().map_or_else(Name::missing, |it| it.as_name());
             // FIXME: Use `Path::from_src`
             let default = type_param.default_type().map(TypeRef::from_ast);
-            let param = GenericParam { idx: idx as u32 + start, name: name.clone(), default };
-            self.params.push(param);
+            let param = TypeParamData { name: name.clone(), default };
+            let param_id = self.types.alloc(param);
+            sm.insert(param_id, Either::Right(type_param.clone()));
 
             let type_ref = TypeRef::Path(name.into());
             self.fill_bounds(&type_param, type_ref);
@@ -139,45 +173,31 @@ impl GenericParams {
         self.where_predicates.push(WherePredicate { type_ref, bound });
     }
 
-    pub fn find_by_name(&self, name: &Name) -> Option<&GenericParam> {
-        self.params.iter().find(|p| &p.name == name)
-    }
-
-    pub fn count_parent_params(&self) -> usize {
-        self.parent_params.as_ref().map(|p| p.count_params_including_parent()).unwrap_or(0)
-    }
-
-    pub fn count_params_including_parent(&self) -> usize {
-        let parent_count = self.count_parent_params();
-        parent_count + self.params.len()
-    }
-
-    fn for_each_param<'a>(&'a self, f: &mut impl FnMut(&'a GenericParam)) {
-        if let Some(parent) = &self.parent_params {
-            parent.for_each_param(f);
-        }
-        self.params.iter().for_each(f);
+    pub fn find_by_name(&self, name: &Name) -> Option<LocalTypeParamId> {
+        self.types.iter().find_map(|(id, p)| if &p.name == name { Some(id) } else { None })
     }
+}
 
-    pub fn params_including_parent(&self) -> Vec<&GenericParam> {
-        let mut vec = Vec::with_capacity(self.count_params_including_parent());
-        self.for_each_param(&mut |p| vec.push(p));
-        vec
+impl HasChildSource for GenericDefId {
+    type ChildId = LocalTypeParamId;
+    type Value = Either<ast::TraitDef, ast::TypeParam>;
+    fn child_source(&self, db: &impl DefDatabase) -> InFile<SourceMap> {
+        let (_, sm) = GenericParams::new(db, *self);
+        sm
     }
 }
 
-fn parent_generic_def(db: &impl DefDatabase, def: GenericDefId) -> Option<GenericDefId> {
-    let container = match def {
-        GenericDefId::FunctionId(it) => it.lookup(db).container,
-        GenericDefId::TypeAliasId(it) => it.lookup(db).container,
-        GenericDefId::ConstId(it) => it.lookup(db).container,
-        GenericDefId::EnumVariantId(it) => return Some(it.parent.into()),
-        GenericDefId::AdtId(_) | GenericDefId::TraitId(_) | GenericDefId::ImplId(_) => return None,
-    };
-
-    match container {
-        ContainerId::ImplId(it) => Some(it.into()),
-        ContainerId::TraitId(it) => Some(it.into()),
-        ContainerId::ModuleId(_) => None,
+impl ChildBySource for GenericDefId {
+    fn child_by_source(&self, db: &impl DefDatabase) -> DynMap {
+        let mut res = DynMap::default();
+        let arena_map = self.child_source(db);
+        let arena_map = arena_map.as_ref();
+        for (local_id, src) in arena_map.value.iter() {
+            let id = TypeParamId { parent: *self, local_id };
+            if let Either::Right(type_param) = src {
+                res[keys::TYPE_PARAM].insert(arena_map.with_value(type_param.clone()), id)
+            }
+        }
+        res
     }
 }
diff --git a/crates/ra_hir_def/src/item_scope.rs b/crates/ra_hir_def/src/item_scope.rs
new file mode 100644
index 000000000..b0288ee8d
--- /dev/null
+++ b/crates/ra_hir_def/src/item_scope.rs
@@ -0,0 +1,172 @@
+//! Describes items defined or visible (ie, imported) in a certain scope.
+//! This is shared between modules and blocks.
+
+use hir_expand::name::Name;
+use once_cell::sync::Lazy;
+use rustc_hash::FxHashMap;
+
+use crate::{per_ns::PerNs, AdtId, BuiltinType, ImplId, MacroDefId, ModuleDefId, TraitId};
+
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct ItemScope {
+    visible: FxHashMap<Name, PerNs>,
+    defs: Vec<ModuleDefId>,
+    impls: Vec<ImplId>,
+    /// Macros visible in current module in legacy textual scope
+    ///
+    /// For macros invoked by an unqualified identifier like `bar!()`, `legacy_macros` will be searched in first.
+    /// If it yields no result, then it turns to module scoped `macros`.
+    /// It macros with name qualified with a path like `crate::foo::bar!()`, `legacy_macros` will be skipped,
+    /// and only normal scoped `macros` will be searched in.
+    ///
+    /// Note that this automatically inherit macros defined textually before the definition of module itself.
+    ///
+    /// Module scoped macros will be inserted into `items` instead of here.
+    // FIXME: Macro shadowing in one module is not properly handled. Non-item place macros will
+    // be all resolved to the last one defined if shadowing happens.
+    legacy_macros: FxHashMap<Name, MacroDefId>,
+}
+
+static BUILTIN_SCOPE: Lazy<FxHashMap<Name, PerNs>> = Lazy::new(|| {
+    BuiltinType::ALL
+        .iter()
+        .map(|(name, ty)| (name.clone(), PerNs::types(ty.clone().into())))
+        .collect()
+});
+
+/// Shadow mode for builtin type which can be shadowed by module.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+pub(crate) enum BuiltinShadowMode {
+    // Prefer Module
+    Module,
+    // Prefer Other Types
+    Other,
+}
+
+/// Legacy macros can only be accessed through special methods like `get_legacy_macros`.
+/// Other methods will only resolve values, types and module scoped macros only.
+impl ItemScope {
+    pub fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a Name, PerNs)> + 'a {
+        //FIXME: shadowing
+        self.visible.iter().chain(BUILTIN_SCOPE.iter()).map(|(n, def)| (n, *def))
+    }
+
+    pub fn entries_without_primitives<'a>(
+        &'a self,
+    ) -> impl Iterator<Item = (&'a Name, PerNs)> + 'a {
+        self.visible.iter().map(|(n, def)| (n, *def))
+    }
+
+    pub fn declarations(&self) -> impl Iterator<Item = ModuleDefId> + '_ {
+        self.defs.iter().copied()
+    }
+
+    pub fn impls(&self) -> impl Iterator<Item = ImplId> + ExactSizeIterator + '_ {
+        self.impls.iter().copied()
+    }
+
+    /// Iterate over all module scoped macros
+    pub(crate) fn macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
+        self.visible.iter().filter_map(|(name, def)| def.take_macros().map(|macro_| (name, macro_)))
+    }
+
+    /// Iterate over all legacy textual scoped macros visible at the end of the module
+    pub(crate) fn legacy_macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
+        self.legacy_macros.iter().map(|(name, def)| (name, *def))
+    }
+
+    /// Get a name from current module scope, legacy macros are not included
+    pub(crate) fn get(&self, name: &Name, shadow: BuiltinShadowMode) -> PerNs {
+        match shadow {
+            BuiltinShadowMode::Module => self
+                .visible
+                .get(name)
+                .or_else(|| BUILTIN_SCOPE.get(name))
+                .copied()
+                .unwrap_or_else(PerNs::none),
+            BuiltinShadowMode::Other => {
+                let item = self.visible.get(name).copied();
+                if let Some(def) = item {
+                    if let Some(ModuleDefId::ModuleId(_)) = def.take_types() {
+                        return BUILTIN_SCOPE
+                            .get(name)
+                            .copied()
+                            .or(item)
+                            .unwrap_or_else(PerNs::none);
+                    }
+                }
+
+                item.or_else(|| BUILTIN_SCOPE.get(name).copied()).unwrap_or_else(PerNs::none)
+            }
+        }
+    }
+
+    pub(crate) fn traits<'a>(&'a self) -> impl Iterator<Item = TraitId> + 'a {
+        self.visible.values().filter_map(|def| match def.take_types() {
+            Some(ModuleDefId::TraitId(t)) => Some(t),
+            _ => None,
+        })
+    }
+
+    pub(crate) fn define_def(&mut self, def: ModuleDefId) {
+        self.defs.push(def)
+    }
+
+    pub(crate) fn get_legacy_macro(&self, name: &Name) -> Option<MacroDefId> {
+        self.legacy_macros.get(name).copied()
+    }
+
+    pub(crate) fn define_impl(&mut self, imp: ImplId) {
+        self.impls.push(imp)
+    }
+
+    pub(crate) fn define_legacy_macro(&mut self, name: Name, mac: MacroDefId) {
+        self.legacy_macros.insert(name, mac);
+    }
+
+    pub(crate) fn push_res(&mut self, name: Name, def: PerNs) -> bool {
+        let mut changed = false;
+        let existing = self.visible.entry(name.clone()).or_default();
+
+        if existing.types.is_none() && def.types.is_some() {
+            existing.types = def.types;
+            changed = true;
+        }
+        if existing.values.is_none() && def.values.is_some() {
+            existing.values = def.values;
+            changed = true;
+        }
+        if existing.macros.is_none() && def.macros.is_some() {
+            existing.macros = def.macros;
+            changed = true;
+        }
+
+        changed
+    }
+
+    pub(crate) fn collect_resolutions(&self) -> Vec<(Name, PerNs)> {
+        self.visible.iter().map(|(name, res)| (name.clone(), res.clone())).collect()
+    }
+
+    pub(crate) fn collect_legacy_macros(&self) -> FxHashMap<Name, MacroDefId> {
+        self.legacy_macros.clone()
+    }
+}
+
+impl From<ModuleDefId> for PerNs {
+    fn from(def: ModuleDefId) -> PerNs {
+        match def {
+            ModuleDefId::ModuleId(_) => PerNs::types(def),
+            ModuleDefId::FunctionId(_) => PerNs::values(def),
+            ModuleDefId::AdtId(adt) => match adt {
+                AdtId::StructId(_) | AdtId::UnionId(_) => PerNs::both(def, def),
+                AdtId::EnumId(_) => PerNs::types(def),
+            },
+            ModuleDefId::EnumVariantId(_) => PerNs::both(def, def),
+            ModuleDefId::ConstId(_) | ModuleDefId::StaticId(_) => PerNs::values(def),
+            ModuleDefId::TraitId(_) => PerNs::types(def),
+            ModuleDefId::TypeAliasId(_) => PerNs::types(def),
+            ModuleDefId::BuiltinType(_) => PerNs::types(def),
+        }
+    }
+}
diff --git a/crates/ra_hir_def/src/keys.rs b/crates/ra_hir_def/src/keys.rs
new file mode 100644
index 000000000..d844f7a62
--- /dev/null
+++ b/crates/ra_hir_def/src/keys.rs
@@ -0,0 +1,56 @@
+//! keys to be used with `DynMap`
+
+use std::marker::PhantomData;
+
+use hir_expand::InFile;
+use ra_syntax::{ast, AstNode, AstPtr};
+use rustc_hash::FxHashMap;
+
+use crate::{
+    dyn_map::{DynMap, Policy},
+    ConstId, EnumId, EnumVariantId, FunctionId, ImplId, StaticId, StructFieldId, StructId, TraitId,
+    TypeAliasId, TypeParamId, UnionId,
+};
+
+pub type Key<K, V> = crate::dyn_map::Key<InFile<K>, V, AstPtrPolicy<K, V>>;
+
+pub const FUNCTION: Key<ast::FnDef, FunctionId> = Key::new();
+pub const CONST: Key<ast::ConstDef, ConstId> = Key::new();
+pub const STATIC: Key<ast::StaticDef, StaticId> = Key::new();
+pub const TYPE_ALIAS: Key<ast::TypeAliasDef, TypeAliasId> = Key::new();
+pub const IMPL: Key<ast::ImplBlock, ImplId> = Key::new();
+pub const TRAIT: Key<ast::TraitDef, TraitId> = Key::new();
+pub const STRUCT: Key<ast::StructDef, StructId> = Key::new();
+pub const UNION: Key<ast::UnionDef, UnionId> = Key::new();
+pub const ENUM: Key<ast::EnumDef, EnumId> = Key::new();
+
+pub const ENUM_VARIANT: Key<ast::EnumVariant, EnumVariantId> = Key::new();
+pub const TUPLE_FIELD: Key<ast::TupleFieldDef, StructFieldId> = Key::new();
+pub const RECORD_FIELD: Key<ast::RecordFieldDef, StructFieldId> = Key::new();
+pub const TYPE_PARAM: Key<ast::TypeParam, TypeParamId> = Key::new();
+
+/// XXX: AST Nodes and SyntaxNodes have identity equality semantics: nodes are
+/// equal if they point to exactly the same object.
+///
+/// In general, we do not guarantee that we have exactly one instance of a
+/// syntax tree for each file. We probably should add such guarantee, but, for
+/// the time being, we will use identity-less AstPtr comparison.
+pub struct AstPtrPolicy<AST, ID> {
+    _phantom: PhantomData<(AST, ID)>,
+}
+
+impl<AST: AstNode + 'static, ID: 'static> Policy for AstPtrPolicy<AST, ID> {
+    type K = InFile<AST>;
+    type V = ID;
+    fn insert(map: &mut DynMap, key: InFile<AST>, value: ID) {
+        let key = key.as_ref().map(AstPtr::new);
+        map.map
+            .entry::<FxHashMap<InFile<AstPtr<AST>>, ID>>()
+            .or_insert_with(Default::default)
+            .insert(key, value);
+    }
+    fn get<'a>(map: &'a DynMap, key: &InFile<AST>) -> Option<&'a ID> {
+        let key = key.as_ref().map(AstPtr::new);
+        map.map.get::<FxHashMap<InFile<AstPtr<AST>>, ID>>()?.get(&key)
+    }
+}
diff --git a/crates/ra_hir_def/src/lang_item.rs b/crates/ra_hir_def/src/lang_item.rs
index f4fdbdcfc..cef061837 100644
--- a/crates/ra_hir_def/src/lang_item.rs
+++ b/crates/ra_hir_def/src/lang_item.rs
@@ -81,7 +81,7 @@ impl LangItems {
         // Look for impl targets
         let def_map = db.crate_def_map(module.krate);
         let module_data = &def_map[module.local_id];
-        for &impl_block in module_data.impls.iter() {
+        for impl_block in module_data.scope.impls() {
             self.collect_lang_item(db, impl_block, LangItemTarget::ImplBlockId)
         }
 
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index bc5530896..f6c7f38d1 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -15,6 +15,10 @@ pub mod type_ref;
 pub mod builtin_type;
 pub mod diagnostics;
 pub mod per_ns;
+pub mod item_scope;
+
+pub mod dyn_map;
+pub mod keys;
 
 pub mod adt;
 pub mod data;
@@ -29,23 +33,23 @@ pub mod resolver;
 mod trace;
 pub mod nameres;
 
+pub mod src;
+pub mod child_by_source;
+
 #[cfg(test)]
 mod test_db;
 #[cfg(test)]
 mod marks;
 
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
 
-use hir_expand::{ast_id_map::FileAstId, db::AstDatabase, AstId, HirFileId, MacroDefId, Source};
-use ra_arena::{impl_arena_id, map::ArenaMap, RawId};
+use hir_expand::{ast_id_map::FileAstId, AstId, HirFileId, InFile, MacroDefId};
+use ra_arena::{impl_arena_id, RawId};
 use ra_db::{impl_intern_key, salsa, CrateId};
 use ra_syntax::{ast, AstNode};
 
-use crate::{builtin_type::BuiltinType, db::InternDatabase};
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct LocalImportId(RawId);
-impl_arena_id!(LocalImportId);
+use crate::body::Expander;
+use crate::builtin_type::BuiltinType;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ModuleId {
@@ -59,122 +63,57 @@ pub struct ModuleId {
 pub struct LocalModuleId(RawId);
 impl_arena_id!(LocalModuleId);
 
-#[derive(Debug)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ItemLoc<N: AstNode> {
-    pub(crate) module: ModuleId,
-    ast_id: AstId<N>,
-}
-
-impl<N: AstNode> PartialEq for ItemLoc<N> {
-    fn eq(&self, other: &Self) -> bool {
-        self.module == other.module && self.ast_id == other.ast_id
-    }
-}
-impl<N: AstNode> Eq for ItemLoc<N> {}
-impl<N: AstNode> Hash for ItemLoc<N> {
-    fn hash<H: Hasher>(&self, hasher: &mut H) {
-        self.module.hash(hasher);
-        self.ast_id.hash(hasher);
-    }
-}
-
-impl<N: AstNode> Clone for ItemLoc<N> {
-    fn clone(&self) -> ItemLoc<N> {
-        ItemLoc { module: self.module, ast_id: self.ast_id }
-    }
+    pub container: ContainerId,
+    pub ast_id: AstId<N>,
 }
 
-#[derive(Clone, Copy)]
-pub struct LocationCtx<DB> {
-    db: DB,
-    module: ModuleId,
-    file_id: HirFileId,
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct AssocItemLoc<N: AstNode> {
+    pub container: AssocContainerId,
+    pub ast_id: AstId<N>,
 }
 
-impl<'a, DB> LocationCtx<&'a DB> {
-    pub fn new(db: &'a DB, module: ModuleId, file_id: HirFileId) -> LocationCtx<&'a DB> {
-        LocationCtx { db, module, file_id }
-    }
-}
+macro_rules! impl_intern {
+    ($id:ident, $loc:ident, $intern:ident, $lookup:ident) => {
+        impl_intern_key!($id);
 
-pub trait AstItemDef<N: AstNode>: salsa::InternKey + Clone {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<N>) -> Self;
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<N>;
+        impl Intern for $loc {
+            type ID = $id;
+            fn intern(self, db: &impl db::DefDatabase) -> $id {
+                db.$intern(self)
+            }
+        }
 
-    fn from_ast_id(ctx: LocationCtx<&impl InternDatabase>, ast_id: FileAstId<N>) -> Self {
-        let loc = ItemLoc { module: ctx.module, ast_id: AstId::new(ctx.file_id, ast_id) };
-        Self::intern(ctx.db, loc)
-    }
-    fn source(self, db: &(impl AstDatabase + InternDatabase)) -> Source<N> {
-        let loc = self.lookup_intern(db);
-        let value = loc.ast_id.to_node(db);
-        Source { file_id: loc.ast_id.file_id(), value }
-    }
-    fn module(self, db: &impl InternDatabase) -> ModuleId {
-        let loc = self.lookup_intern(db);
-        loc.module
-    }
+        impl Lookup for $id {
+            type Data = $loc;
+            fn lookup(&self, db: &impl db::DefDatabase) -> $loc {
+                db.$lookup(*self)
+            }
+        }
+    };
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct FunctionId(salsa::InternId);
-impl_intern_key!(FunctionId);
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct FunctionLoc {
-    pub container: ContainerId,
-    pub ast_id: AstId<ast::FnDef>,
-}
-
-impl Intern for FunctionLoc {
-    type ID = FunctionId;
-    fn intern(self, db: &impl db::DefDatabase) -> FunctionId {
-        db.intern_function(self)
-    }
-}
-
-impl Lookup for FunctionId {
-    type Data = FunctionLoc;
-    fn lookup(&self, db: &impl db::DefDatabase) -> FunctionLoc {
-        db.lookup_intern_function(*self)
-    }
-}
+type FunctionLoc = AssocItemLoc<ast::FnDef>;
+impl_intern!(FunctionId, FunctionLoc, intern_function, lookup_intern_function);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StructId(salsa::InternId);
-impl_intern_key!(StructId);
-impl AstItemDef<ast::StructDef> for StructId {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::StructDef>) -> Self {
-        db.intern_struct(loc)
-    }
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::StructDef> {
-        db.lookup_intern_struct(self)
-    }
-}
+type StructLoc = ItemLoc<ast::StructDef>;
+impl_intern!(StructId, StructLoc, intern_struct, lookup_intern_struct);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct UnionId(salsa::InternId);
-impl_intern_key!(UnionId);
-impl AstItemDef<ast::UnionDef> for UnionId {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::UnionDef>) -> Self {
-        db.intern_union(loc)
-    }
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::UnionDef> {
-        db.lookup_intern_union(self)
-    }
-}
+pub type UnionLoc = ItemLoc<ast::UnionDef>;
+impl_intern!(UnionId, UnionLoc, intern_union, lookup_intern_union);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct EnumId(salsa::InternId);
-impl_intern_key!(EnumId);
-impl AstItemDef<ast::EnumDef> for EnumId {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::EnumDef>) -> Self {
-        db.intern_enum(loc)
-    }
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::EnumDef> {
-        db.lookup_intern_enum(self)
-    }
-}
+pub type EnumLoc = ItemLoc<ast::EnumDef>;
+impl_intern!(EnumId, EnumLoc, intern_enum, lookup_intern_enum);
 
 // FIXME: rename to `VariantId`, only enums can ave variants
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -199,98 +138,38 @@ impl_arena_id!(LocalStructFieldId);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ConstId(salsa::InternId);
-impl_intern_key!(ConstId);
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct ConstLoc {
-    pub container: ContainerId,
-    pub ast_id: AstId<ast::ConstDef>,
-}
-
-impl Intern for ConstLoc {
-    type ID = ConstId;
-    fn intern(self, db: &impl db::DefDatabase) -> ConstId {
-        db.intern_const(self)
-    }
-}
-
-impl Lookup for ConstId {
-    type Data = ConstLoc;
-    fn lookup(&self, db: &impl db::DefDatabase) -> ConstLoc {
-        db.lookup_intern_const(*self)
-    }
-}
+type ConstLoc = AssocItemLoc<ast::ConstDef>;
+impl_intern!(ConstId, ConstLoc, intern_const, lookup_intern_const);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StaticId(salsa::InternId);
-impl_intern_key!(StaticId);
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct StaticLoc {
-    pub container: ModuleId,
-    pub ast_id: AstId<ast::StaticDef>,
-}
-
-impl Intern for StaticLoc {
-    type ID = StaticId;
-    fn intern(self, db: &impl db::DefDatabase) -> StaticId {
-        db.intern_static(self)
-    }
-}
-
-impl Lookup for StaticId {
-    type Data = StaticLoc;
-    fn lookup(&self, db: &impl db::DefDatabase) -> StaticLoc {
-        db.lookup_intern_static(*self)
-    }
-}
+pub type StaticLoc = ItemLoc<ast::StaticDef>;
+impl_intern!(StaticId, StaticLoc, intern_static, lookup_intern_static);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TraitId(salsa::InternId);
-impl_intern_key!(TraitId);
-impl AstItemDef<ast::TraitDef> for TraitId {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::TraitDef>) -> Self {
-        db.intern_trait(loc)
-    }
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::TraitDef> {
-        db.lookup_intern_trait(self)
-    }
-}
+pub type TraitLoc = ItemLoc<ast::TraitDef>;
+impl_intern!(TraitId, TraitLoc, intern_trait, lookup_intern_trait);
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct TypeAliasId(salsa::InternId);
-impl_intern_key!(TypeAliasId);
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct TypeAliasLoc {
-    pub container: ContainerId,
-    pub ast_id: AstId<ast::TypeAliasDef>,
-}
+type TypeAliasLoc = AssocItemLoc<ast::TypeAliasDef>;
+impl_intern!(TypeAliasId, TypeAliasLoc, intern_type_alias, lookup_intern_type_alias);
 
-impl Intern for TypeAliasLoc {
-    type ID = TypeAliasId;
-    fn intern(self, db: &impl db::DefDatabase) -> TypeAliasId {
-        db.intern_type_alias(self)
-    }
-}
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct ImplId(salsa::InternId);
+type ImplLoc = ItemLoc<ast::ImplBlock>;
+impl_intern!(ImplId, ImplLoc, intern_impl, lookup_intern_impl);
 
-impl Lookup for TypeAliasId {
-    type Data = TypeAliasLoc;
-    fn lookup(&self, db: &impl db::DefDatabase) -> TypeAliasLoc {
-        db.lookup_intern_type_alias(*self)
-    }
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct TypeParamId {
+    pub parent: GenericDefId,
+    pub local_id: LocalTypeParamId,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ImplId(salsa::InternId);
-impl_intern_key!(ImplId);
-impl AstItemDef<ast::ImplBlock> for ImplId {
-    fn intern(db: &impl InternDatabase, loc: ItemLoc<ast::ImplBlock>) -> Self {
-        db.intern_impl(loc)
-    }
-    fn lookup_intern(self, db: &impl InternDatabase) -> ItemLoc<ast::ImplBlock> {
-        db.lookup_intern_impl(self)
-    }
-}
+pub struct LocalTypeParamId(RawId);
+impl_arena_id!(LocalTypeParamId);
 
 macro_rules! impl_froms {
     ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
@@ -314,9 +193,16 @@ macro_rules! impl_froms {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum ContainerId {
     ModuleId(ModuleId),
+    DefWithBodyId(DefWithBodyId),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum AssocContainerId {
+    ContainerId(ContainerId),
     ImplId(ImplId),
     TraitId(TraitId),
 }
+impl_froms!(AssocContainerId: ContainerId);
 
 /// A Data Type
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
@@ -459,43 +345,39 @@ pub trait HasModule {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId;
 }
 
-impl HasModule for FunctionLoc {
+impl HasModule for ContainerId {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
-        match self.container {
+        match *self {
             ContainerId::ModuleId(it) => it,
-            ContainerId::ImplId(it) => it.module(db),
-            ContainerId::TraitId(it) => it.module(db),
+            ContainerId::DefWithBodyId(it) => it.module(db),
         }
     }
 }
 
-impl HasModule for TypeAliasLoc {
+impl HasModule for AssocContainerId {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
-        match self.container {
-            ContainerId::ModuleId(it) => it,
-            ContainerId::ImplId(it) => it.module(db),
-            ContainerId::TraitId(it) => it.module(db),
+        match *self {
+            AssocContainerId::ContainerId(it) => it.module(db),
+            AssocContainerId::ImplId(it) => it.lookup(db).container.module(db),
+            AssocContainerId::TraitId(it) => it.lookup(db).container.module(db),
         }
     }
 }
 
-impl HasModule for ConstLoc {
+impl<N: AstNode> HasModule for AssocItemLoc<N> {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
-        match self.container {
-            ContainerId::ModuleId(it) => it,
-            ContainerId::ImplId(it) => it.module(db),
-            ContainerId::TraitId(it) => it.module(db),
-        }
+        self.container.module(db)
     }
 }
 
 impl HasModule for AdtId {
     fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
         match self {
-            AdtId::StructId(it) => it.module(db),
-            AdtId::UnionId(it) => it.module(db),
-            AdtId::EnumId(it) => it.module(db),
+            AdtId::StructId(it) => it.lookup(db).container,
+            AdtId::UnionId(it) => it.lookup(db).container,
+            AdtId::EnumId(it) => it.lookup(db).container,
         }
+        .module(db)
     }
 }
 
@@ -509,58 +391,22 @@ impl HasModule for DefWithBodyId {
     }
 }
 
-impl HasModule for StaticLoc {
-    fn module(&self, _db: &impl db::DefDatabase) -> ModuleId {
-        self.container
-    }
-}
-
-pub trait HasSource {
-    type Value;
-    fn source(&self, db: &impl db::DefDatabase) -> Source<Self::Value>;
-}
-
-impl HasSource for FunctionLoc {
-    type Value = ast::FnDef;
-
-    fn source(&self, db: &impl db::DefDatabase) -> Source<ast::FnDef> {
-        let node = self.ast_id.to_node(db);
-        Source::new(self.ast_id.file_id(), node)
-    }
-}
-
-impl HasSource for TypeAliasLoc {
-    type Value = ast::TypeAliasDef;
-
-    fn source(&self, db: &impl db::DefDatabase) -> Source<ast::TypeAliasDef> {
-        let node = self.ast_id.to_node(db);
-        Source::new(self.ast_id.file_id(), node)
-    }
-}
-
-impl HasSource for ConstLoc {
-    type Value = ast::ConstDef;
-
-    fn source(&self, db: &impl db::DefDatabase) -> Source<ast::ConstDef> {
-        let node = self.ast_id.to_node(db);
-        Source::new(self.ast_id.file_id(), node)
+impl HasModule for GenericDefId {
+    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
+        match self {
+            GenericDefId::FunctionId(it) => it.lookup(db).module(db),
+            GenericDefId::AdtId(it) => it.module(db),
+            GenericDefId::TraitId(it) => it.lookup(db).container.module(db),
+            GenericDefId::TypeAliasId(it) => it.lookup(db).module(db),
+            GenericDefId::ImplId(it) => it.lookup(db).container.module(db),
+            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
+            GenericDefId::ConstId(it) => it.lookup(db).module(db),
+        }
     }
 }
 
-impl HasSource for StaticLoc {
-    type Value = ast::StaticDef;
-
-    fn source(&self, db: &impl db::DefDatabase) -> Source<ast::StaticDef> {
-        let node = self.ast_id.to_node(db);
-        Source::new(self.ast_id.file_id(), node)
+impl HasModule for StaticLoc {
+    fn module(&self, db: &impl db::DefDatabase) -> ModuleId {
+        self.container.module(db)
     }
 }
-
-pub trait HasChildSource {
-    type ChildId;
-    type Value;
-    fn child_source(
-        &self,
-        db: &impl db::DefDatabase,
-    ) -> Source<ArenaMap<Self::ChildId, Self::Value>>;
-}
diff --git a/crates/ra_hir_def/src/marks.rs b/crates/ra_hir_def/src/marks.rs
index 65239ca0a..457ba4abe 100644
--- a/crates/ra_hir_def/src/marks.rs
+++ b/crates/ra_hir_def/src/marks.rs
@@ -5,6 +5,7 @@ test_utils::marks!(
     name_res_works_for_broken_modules
     can_import_enum_variant
     glob_enum
+    glob_enum_group
     glob_across_crates
     std_prelude
     macro_rules_from_other_crates_are_visible_with_macro_use
diff --git a/crates/ra_hir_def/src/nameres.rs b/crates/ra_hir_def/src/nameres.rs
index 2359386c2..5d4ca73a3 100644
--- a/crates/ra_hir_def/src/nameres.rs
+++ b/crates/ra_hir_def/src/nameres.rs
@@ -57,24 +57,23 @@ mod tests;
 
 use std::sync::Arc;
 
-use hir_expand::{
-    ast_id_map::FileAstId, diagnostics::DiagnosticSink, either::Either, name::Name, MacroDefId,
-    Source,
-};
-use once_cell::sync::Lazy;
+use hir_expand::{diagnostics::DiagnosticSink, name::Name, InFile};
 use ra_arena::Arena;
-use ra_db::{CrateId, Edition, FileId};
+use ra_db::{CrateId, Edition, FileId, FilePosition};
 use ra_prof::profile;
-use ra_syntax::ast;
+use ra_syntax::{
+    ast::{self, AstNode},
+    SyntaxNode,
+};
 use rustc_hash::FxHashMap;
 
 use crate::{
-    builtin_type::BuiltinType,
     db::DefDatabase,
+    item_scope::{BuiltinShadowMode, ItemScope},
     nameres::{diagnostics::DefDiagnostic, path_resolution::ResolveMode},
-    path::Path,
+    path::ModPath,
     per_ns::PerNs,
-    AstId, FunctionId, ImplId, LocalImportId, LocalModuleId, ModuleDefId, ModuleId, TraitId,
+    AstId, LocalModuleId, ModuleDefId, ModuleId,
 };
 
 /// Contains all top-level defs from a macro-expanded crate
@@ -100,106 +99,76 @@ impl std::ops::Index<LocalModuleId> for CrateDefMap {
     }
 }
 
-#[derive(Default, Debug, PartialEq, Eq)]
-pub struct ModuleData {
-    pub parent: Option<LocalModuleId>,
-    pub children: FxHashMap<Name, LocalModuleId>,
-    pub scope: ModuleScope,
-
-    //  FIXME: these can't be both null, we need a three-state enum here.
-    /// None for root
-    pub declaration: Option<AstId<ast::Module>>,
-    /// None for inline modules.
-    ///
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
+pub enum ModuleOrigin {
+    CrateRoot {
+        definition: FileId,
+    },
     /// Note that non-inline modules, by definition, live inside non-macro file.
-    pub definition: Option<FileId>,
-
-    pub impls: Vec<ImplId>,
-}
-
-#[derive(Default, Debug, PartialEq, Eq)]
-pub(crate) struct Declarations {
-    fns: FxHashMap<FileAstId<ast::FnDef>, FunctionId>,
+    File {
+        declaration: AstId<ast::Module>,
+        definition: FileId,
+    },
+    Inline {
+        definition: AstId<ast::Module>,
+    },
 }
 
-#[derive(Debug, Default, PartialEq, Eq)]
-pub struct ModuleScope {
-    items: FxHashMap<Name, Resolution>,
-    /// Macros visable in current module in legacy textual scope
-    ///
-    /// For macros invoked by an unquatified identifier like `bar!()`, `legacy_macros` will be searched in first.
-    /// If it yields no result, then it turns to module scoped `macros`.
-    /// It macros with name quatified with a path like `crate::foo::bar!()`, `legacy_macros` will be skipped,
-    /// and only normal scoped `macros` will be searched in.
-    ///
-    /// Note that this automatically inherit macros defined textually before the definition of module itself.
-    ///
-    /// Module scoped macros will be inserted into `items` instead of here.
-    // FIXME: Macro shadowing in one module is not properly handled. Non-item place macros will
-    // be all resolved to the last one defined if shadowing happens.
-    legacy_macros: FxHashMap<Name, MacroDefId>,
-}
-
-static BUILTIN_SCOPE: Lazy<FxHashMap<Name, Resolution>> = Lazy::new(|| {
-    BuiltinType::ALL
-        .iter()
-        .map(|(name, ty)| {
-            (name.clone(), Resolution { def: PerNs::types(ty.clone().into()), import: None })
-        })
-        .collect()
-});
-
-/// Legacy macros can only be accessed through special methods like `get_legacy_macros`.
-/// Other methods will only resolve values, types and module scoped macros only.
-impl ModuleScope {
-    pub fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a Name, &'a Resolution)> + 'a {
-        //FIXME: shadowing
-        self.items.iter().chain(BUILTIN_SCOPE.iter())
-    }
-
-    pub fn declarations(&self) -> impl Iterator<Item = ModuleDefId> + '_ {
-        self.entries()
-            .filter_map(|(_name, res)| if res.import.is_none() { Some(res.def) } else { None })
-            .flat_map(|per_ns| {
-                per_ns.take_types().into_iter().chain(per_ns.take_values().into_iter())
-            })
-    }
-
-    /// Iterate over all module scoped macros
-    pub fn macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
-        self.items
-            .iter()
-            .filter_map(|(name, res)| res.def.take_macros().map(|macro_| (name, macro_)))
+impl Default for ModuleOrigin {
+    fn default() -> Self {
+        ModuleOrigin::CrateRoot { definition: FileId(0) }
     }
+}
 
-    /// Iterate over all legacy textual scoped macros visable at the end of the module
-    pub fn legacy_macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
-        self.legacy_macros.iter().map(|(name, def)| (name, *def))
+impl ModuleOrigin {
+    pub(crate) fn not_sure_file(file: Option<FileId>, declaration: AstId<ast::Module>) -> Self {
+        match file {
+            None => ModuleOrigin::Inline { definition: declaration },
+            Some(definition) => ModuleOrigin::File { declaration, definition },
+        }
     }
 
-    /// Get a name from current module scope, legacy macros are not included
-    pub fn get(&self, name: &Name) -> Option<&Resolution> {
-        self.items.get(name).or_else(|| BUILTIN_SCOPE.get(name))
+    fn declaration(&self) -> Option<AstId<ast::Module>> {
+        match self {
+            ModuleOrigin::File { declaration: module, .. }
+            | ModuleOrigin::Inline { definition: module, .. } => Some(*module),
+            ModuleOrigin::CrateRoot { .. } => None,
+        }
     }
 
-    pub fn traits<'a>(&'a self) -> impl Iterator<Item = TraitId> + 'a {
-        self.items.values().filter_map(|r| match r.def.take_types() {
-            Some(ModuleDefId::TraitId(t)) => Some(t),
+    pub fn file_id(&self) -> Option<FileId> {
+        match self {
+            ModuleOrigin::File { definition, .. } | ModuleOrigin::CrateRoot { definition } => {
+                Some(*definition)
+            }
             _ => None,
-        })
+        }
     }
 
-    fn get_legacy_macro(&self, name: &Name) -> Option<MacroDefId> {
-        self.legacy_macros.get(name).copied()
+    /// Returns a node which defines this module.
+    /// That is, a file or a `mod foo {}` with items.
+    fn definition_source(&self, db: &impl DefDatabase) -> InFile<ModuleSource> {
+        match self {
+            ModuleOrigin::File { definition, .. } | ModuleOrigin::CrateRoot { definition } => {
+                let file_id = *definition;
+                let sf = db.parse(file_id).tree();
+                return InFile::new(file_id.into(), ModuleSource::SourceFile(sf));
+            }
+            ModuleOrigin::Inline { definition } => {
+                InFile::new(definition.file_id, ModuleSource::Module(definition.to_node(db)))
+            }
+        }
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Default)]
-pub struct Resolution {
-    /// None for unresolved
-    pub def: PerNs,
-    /// ident by which this is imported into local scope.
-    pub import: Option<LocalImportId>,
+#[derive(Default, Debug, PartialEq, Eq)]
+pub struct ModuleData {
+    pub parent: Option<LocalModuleId>,
+    pub children: FxHashMap<Name, LocalModuleId>,
+    pub scope: ItemScope,
+
+    /// Where does this module come from?
+    pub origin: ModuleOrigin,
 }
 
 impl CrateDefMap {
@@ -241,7 +210,7 @@ impl CrateDefMap {
     pub fn modules_for_file(&self, file_id: FileId) -> impl Iterator<Item = LocalModuleId> + '_ {
         self.modules
             .iter()
-            .filter(move |(_id, data)| data.definition == Some(file_id))
+            .filter(move |(_id, data)| data.origin.file_id() == Some(file_id))
             .map(|(id, _data)| id)
     }
 
@@ -249,33 +218,62 @@ impl CrateDefMap {
         &self,
         db: &impl DefDatabase,
         original_module: LocalModuleId,
-        path: &Path,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
     ) -> (PerNs, Option<usize>) {
-        let res = self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path);
+        let res =
+            self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path, shadow);
         (res.resolved_def, res.segment_index)
     }
 }
 
 impl ModuleData {
     /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
-    pub fn definition_source(
-        &self,
-        db: &impl DefDatabase,
-    ) -> Source<Either<ast::SourceFile, ast::Module>> {
-        if let Some(file_id) = self.definition {
-            let sf = db.parse(file_id).tree();
-            return Source::new(file_id.into(), Either::A(sf));
-        }
-        let decl = self.declaration.unwrap();
-        Source::new(decl.file_id(), Either::B(decl.to_node(db)))
+    pub fn definition_source(&self, db: &impl DefDatabase) -> InFile<ModuleSource> {
+        self.origin.definition_source(db)
     }
 
     /// Returns a node which declares this module, either a `mod foo;` or a `mod foo {}`.
-    /// `None` for the crate root.
-    pub fn declaration_source(&self, db: &impl DefDatabase) -> Option<Source<ast::Module>> {
-        let decl = self.declaration?;
+    /// `None` for the crate root or block.
+    pub fn declaration_source(&self, db: &impl DefDatabase) -> Option<InFile<ast::Module>> {
+        let decl = self.origin.declaration()?;
         let value = decl.to_node(db);
-        Some(Source { file_id: decl.file_id(), value })
+        Some(InFile { file_id: decl.file_id, value })
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ModuleSource {
+    SourceFile(ast::SourceFile),
+    Module(ast::Module),
+}
+
+impl ModuleSource {
+    // FIXME: this methods do not belong here
+    pub fn from_position(db: &impl DefDatabase, position: FilePosition) -> ModuleSource {
+        let parse = db.parse(position.file_id);
+        match &ra_syntax::algo::find_node_at_offset::<ast::Module>(
+            parse.tree().syntax(),
+            position.offset,
+        ) {
+            Some(m) if !m.has_semi() => ModuleSource::Module(m.clone()),
+            _ => {
+                let source_file = parse.tree();
+                ModuleSource::SourceFile(source_file)
+            }
+        }
+    }
+
+    pub fn from_child_node(db: &impl DefDatabase, child: InFile<&SyntaxNode>) -> ModuleSource {
+        if let Some(m) =
+            child.value.ancestors().filter_map(ast::Module::cast).find(|it| !it.has_semi())
+        {
+            ModuleSource::Module(m)
+        } else {
+            let file_id = child.file_id.original_file(db);
+            let source_file = db.parse(file_id).tree();
+            ModuleSource::SourceFile(source_file)
+        }
     }
 }
 
@@ -309,7 +307,7 @@ mod diagnostics {
                     }
                     let decl = declaration.to_node(db);
                     sink.push(UnresolvedModule {
-                        file: declaration.file_id(),
+                        file: declaration.file_id,
                         decl: AstPtr::new(&decl),
                         candidate: candidate.clone(),
                     })
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index fd8245113..b9f40d3dd 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -4,14 +4,15 @@
 //! resolves imports and expands macros.
 
 use hir_expand::{
+    builtin_derive::find_builtin_derive,
     builtin_macro::find_builtin_macro,
-    name::{self, AsName, Name},
-    HirFileId, MacroCallId, MacroDefId, MacroDefKind, MacroFileKind,
+    name::{name, AsName, Name},
+    HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
 use ra_cfg::CfgOptions;
 use ra_db::{CrateId, FileId};
 use ra_syntax::ast;
-use rustc_hash::{FxHashMap, FxHashSet};
+use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
@@ -19,13 +20,12 @@ use crate::{
     db::DefDatabase,
     nameres::{
         diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
-        raw, CrateDefMap, ModuleData, Resolution, ResolveMode,
+        raw, BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
     },
-    path::{Path, PathKind},
+    path::{ModPath, PathKind},
     per_ns::PerNs,
-    AdtId, AstId, AstItemDef, ConstLoc, ContainerId, EnumId, EnumVariantId, FunctionLoc, ImplId,
-    Intern, LocalImportId, LocalModuleId, LocationCtx, ModuleDefId, ModuleId, StaticLoc, StructId,
-    TraitId, TypeAliasLoc, UnionId,
+    AdtId, AstId, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
+    LocalModuleId, ModuleDefId, ModuleId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
 pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
@@ -57,68 +57,63 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
         def_map,
         glob_imports: FxHashMap::default(),
         unresolved_imports: Vec::new(),
+        resolved_imports: Vec::new(),
+
         unexpanded_macros: Vec::new(),
+        unexpanded_attribute_macros: Vec::new(),
         mod_dirs: FxHashMap::default(),
-        macro_stack_monitor: MacroStackMonitor::default(),
-        poison_macros: FxHashSet::default(),
         cfg_options,
     };
     collector.collect();
     collector.finish()
 }
 
-#[derive(Default)]
-struct MacroStackMonitor {
-    counts: FxHashMap<MacroDefId, u32>,
-
-    /// Mainly use for test
-    validator: Option<Box<dyn Fn(u32) -> bool>>,
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+enum PartialResolvedImport {
+    /// None of any namespaces is resolved
+    Unresolved,
+    /// One of namespaces is resolved
+    Indeterminate(PerNs),
+    /// All namespaces are resolved, OR it is came from other crate
+    Resolved(PerNs),
 }
 
-impl MacroStackMonitor {
-    fn increase(&mut self, macro_def_id: MacroDefId) {
-        *self.counts.entry(macro_def_id).or_default() += 1;
-    }
-
-    fn decrease(&mut self, macro_def_id: MacroDefId) {
-        *self.counts.entry(macro_def_id).or_default() -= 1;
+impl PartialResolvedImport {
+    fn namespaces(&self) -> PerNs {
+        match self {
+            PartialResolvedImport::Unresolved => PerNs::none(),
+            PartialResolvedImport::Indeterminate(ns) => *ns,
+            PartialResolvedImport::Resolved(ns) => *ns,
+        }
     }
+}
 
-    fn is_poison(&self, macro_def_id: MacroDefId) -> bool {
-        let cur = *self.counts.get(&macro_def_id).unwrap_or(&0);
+#[derive(Clone, Debug, Eq, PartialEq)]
+struct ImportDirective {
+    module_id: LocalModuleId,
+    import_id: raw::Import,
+    import: raw::ImportData,
+    status: PartialResolvedImport,
+}
 
-        if let Some(validator) = &self.validator {
-            validator(cur)
-        } else {
-            cur > 100
-        }
-    }
+#[derive(Clone, Debug, Eq, PartialEq)]
+struct MacroDirective {
+    module_id: LocalModuleId,
+    ast_id: AstId<ast::MacroCall>,
+    path: ModPath,
+    legacy: Option<MacroCallId>,
 }
 
 /// Walks the tree of module recursively
 struct DefCollector<'a, DB> {
     db: &'a DB,
     def_map: CrateDefMap,
-    glob_imports: FxHashMap<LocalModuleId, Vec<(LocalModuleId, LocalImportId)>>,
-    unresolved_imports: Vec<(LocalModuleId, LocalImportId, raw::ImportData)>,
-    unexpanded_macros: Vec<(LocalModuleId, AstId<ast::MacroCall>, Path)>,
+    glob_imports: FxHashMap<LocalModuleId, Vec<(LocalModuleId, raw::Import)>>,
+    unresolved_imports: Vec<ImportDirective>,
+    resolved_imports: Vec<ImportDirective>,
+    unexpanded_macros: Vec<MacroDirective>,
+    unexpanded_attribute_macros: Vec<(LocalModuleId, AstId<ast::ModuleItem>, ModPath)>,
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
-
-    /// Some macro use `$tt:tt which mean we have to handle the macro perfectly
-    /// To prevent stack overflow, we add a deep counter here for prevent that.
-    macro_stack_monitor: MacroStackMonitor,
-    /// Some macros are not well-behavior, which leads to infinite loop
-    /// e.g. macro_rules! foo { ($ty:ty) => { foo!($ty); } }
-    /// We mark it down and skip it in collector
-    ///
-    /// FIXME:
-    /// Right now it only handle a poison macro in a single crate,
-    /// such that if other crate try to call that macro,
-    /// the whole process will do again until it became poisoned in that crate.
-    /// We should handle this macro set globally
-    /// However, do we want to put it as a global variable?
-    poison_macros: FxHashSet<MacroDefId>,
-
     cfg_options: &'a CfgOptions,
 }
 
@@ -131,7 +126,7 @@ where
         let file_id = crate_graph.crate_root(self.def_map.krate);
         let raw_items = self.db.raw_items(file_id.into());
         let module_id = self.def_map.root;
-        self.def_map.modules[module_id].definition = Some(file_id);
+        self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id };
         ModCollector {
             def_collector: &mut *self,
             module_id,
@@ -145,9 +140,11 @@ where
         let mut i = 0;
         loop {
             self.db.check_canceled();
-            match (self.resolve_imports(), self.resolve_macros()) {
-                (ReachedFixedPoint::Yes, ReachedFixedPoint::Yes) => break,
-                _ => i += 1,
+            self.resolve_imports();
+
+            match self.resolve_macros() {
+                ReachedFixedPoint::Yes => break,
+                ReachedFixedPoint::No => i += 1,
             }
             if i == 1000 {
                 log::error!("name resolution is stuck");
@@ -155,10 +152,26 @@ where
             }
         }
 
+        // Resolve all indeterminate resolved imports again
+        // As some of the macros will expand newly import shadowing partial resolved imports
+        // FIXME: We maybe could skip this, if we handle the Indetermine imports in `resolve_imports`
+        // correctly
+        let partial_resolved = self.resolved_imports.iter().filter_map(|directive| {
+            if let PartialResolvedImport::Indeterminate(_) = directive.status {
+                let mut directive = directive.clone();
+                directive.status = PartialResolvedImport::Unresolved;
+                Some(directive)
+            } else {
+                None
+            }
+        });
+        self.unresolved_imports.extend(partial_resolved);
+        self.resolve_imports();
+
         let unresolved_imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
         // show unresolved imports in completion, etc
-        for (module_id, import, import_data) in unresolved_imports {
-            self.record_resolved_import(module_id, PerNs::none(), import, &import_data)
+        for directive in unresolved_imports {
+            self.record_resolved_import(&directive)
         }
     }
 
@@ -201,24 +214,20 @@ where
         // In Rust, `#[macro_export]` macros are unconditionally visible at the
         // crate root, even if the parent modules is **not** visible.
         if export {
-            self.update(
-                self.def_map.root,
-                None,
-                &[(name, Resolution { def: PerNs::macros(macro_), import: None })],
-            );
+            self.update(self.def_map.root, &[(name, PerNs::macros(macro_))]);
         }
     }
 
     /// Define a legacy textual scoped macro in module
     ///
-    /// We use a map `legacy_macros` to store all legacy textual scoped macros visable per module.
+    /// We use a map `legacy_macros` to store all legacy textual scoped macros visible per module.
     /// It will clone all macros from parent legacy scope, whose definition is prior to
     /// the definition of current module.
-    /// And also, `macro_use` on a module will import all legacy macros visable inside to
+    /// And also, `macro_use` on a module will import all legacy macros visible inside to
     /// current legacy scope, with possible shadowing.
-    fn define_legacy_macro(&mut self, module_id: LocalModuleId, name: Name, macro_: MacroDefId) {
+    fn define_legacy_macro(&mut self, module_id: LocalModuleId, name: Name, mac: MacroDefId) {
         // Always shadowing
-        self.def_map.modules[module_id].scope.legacy_macros.insert(name, macro_);
+        self.def_map.modules[module_id].scope.define_legacy_macro(name, mac);
     }
 
     /// Import macros from `#[macro_use] extern crate`.
@@ -259,31 +268,43 @@ where
         }
     }
 
-    fn resolve_imports(&mut self) -> ReachedFixedPoint {
-        let mut imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
-        let mut resolved = Vec::new();
-        imports.retain(|(module_id, import, import_data)| {
-            let (def, fp) = self.resolve_import(*module_id, import_data);
-            if fp == ReachedFixedPoint::Yes {
-                resolved.push((*module_id, def, *import, import_data.clone()))
+    /// Import resolution
+    ///
+    /// This is a fix point algorithm. We resolve imports until no forward
+    /// progress in resolving imports is made
+    fn resolve_imports(&mut self) {
+        let mut n_previous_unresolved = self.unresolved_imports.len() + 1;
+
+        while self.unresolved_imports.len() < n_previous_unresolved {
+            n_previous_unresolved = self.unresolved_imports.len();
+            let imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
+            for mut directive in imports {
+                directive.status = self.resolve_import(directive.module_id, &directive.import);
+
+                match directive.status {
+                    PartialResolvedImport::Indeterminate(_) => {
+                        self.record_resolved_import(&directive);
+                        // FIXME: For avoid performance regression,
+                        // we consider an imported resolved if it is indeterminate (i.e not all namespace resolved)
+                        self.resolved_imports.push(directive)
+                    }
+                    PartialResolvedImport::Resolved(_) => {
+                        self.record_resolved_import(&directive);
+                        self.resolved_imports.push(directive)
+                    }
+                    PartialResolvedImport::Unresolved => {
+                        self.unresolved_imports.push(directive);
+                    }
+                }
             }
-            fp == ReachedFixedPoint::No
-        });
-        self.unresolved_imports = imports;
-        // Resolves imports, filling-in module scopes
-        let result =
-            if resolved.is_empty() { ReachedFixedPoint::Yes } else { ReachedFixedPoint::No };
-        for (module_id, def, import, import_data) in resolved {
-            self.record_resolved_import(module_id, def, import, &import_data)
         }
-        result
     }
 
     fn resolve_import(
         &self,
         module_id: LocalModuleId,
         import: &raw::ImportData,
-    ) -> (PerNs, ReachedFixedPoint) {
+    ) -> PartialResolvedImport {
         log::debug!("resolving import: {:?} ({:?})", import, self.def_map.edition);
         if import.is_extern_crate {
             let res = self.def_map.resolve_name_in_extern_prelude(
@@ -292,26 +313,45 @@ where
                     .as_ident()
                     .expect("extern crate should have been desugared to one-element path"),
             );
-            (res, ReachedFixedPoint::Yes)
+            PartialResolvedImport::Resolved(res)
         } else {
             let res = self.def_map.resolve_path_fp_with_macro(
                 self.db,
                 ResolveMode::Import,
                 module_id,
                 &import.path,
+                BuiltinShadowMode::Module,
             );
 
-            (res.resolved_def, res.reached_fixedpoint)
+            let def = res.resolved_def;
+            if res.reached_fixedpoint == ReachedFixedPoint::No {
+                return PartialResolvedImport::Unresolved;
+            }
+
+            if let Some(krate) = res.krate {
+                if krate != self.def_map.krate {
+                    return PartialResolvedImport::Resolved(def);
+                }
+            }
+
+            // Check whether all namespace is resolved
+            if def.take_types().is_some()
+                && def.take_values().is_some()
+                && def.take_macros().is_some()
+            {
+                PartialResolvedImport::Resolved(def)
+            } else {
+                PartialResolvedImport::Indeterminate(def)
+            }
         }
     }
 
-    fn record_resolved_import(
-        &mut self,
-        module_id: LocalModuleId,
-        def: PerNs,
-        import_id: LocalImportId,
-        import: &raw::ImportData,
-    ) {
+    fn record_resolved_import(&mut self, directive: &ImportDirective) {
+        let module_id = directive.module_id;
+        let import_id = directive.import_id;
+        let import = &directive.import;
+        let def = directive.status.namespaces();
+
         if import.is_glob {
             log::debug!("glob import: {:?}", import);
             match def.take_types() {
@@ -326,13 +366,9 @@ where
                         let scope = &item_map[m.local_id].scope;
 
                         // Module scoped macros is included
-                        let items = scope
-                            .items
-                            .iter()
-                            .map(|(name, res)| (name.clone(), res.clone()))
-                            .collect::<Vec<_>>();
+                        let items = scope.collect_resolutions();
 
-                        self.update(module_id, Some(import_id), &items);
+                        self.update(module_id, &items);
                     } else {
                         // glob import from same crate => we do an initial
                         // import, and then need to propagate any further
@@ -340,18 +376,14 @@ where
                         let scope = &self.def_map[m.local_id].scope;
 
                         // Module scoped macros is included
-                        let items = scope
-                            .items
-                            .iter()
-                            .map(|(name, res)| (name.clone(), res.clone()))
-                            .collect::<Vec<_>>();
+                        let items = scope.collect_resolutions();
 
-                        self.update(module_id, Some(import_id), &items);
+                        self.update(module_id, &items);
                         // record the glob import in case we add further items
-                        self.glob_imports
-                            .entry(m.local_id)
-                            .or_default()
-                            .push((module_id, import_id));
+                        let glob = self.glob_imports.entry(m.local_id).or_default();
+                        if !glob.iter().any(|it| *it == (module_id, import_id)) {
+                            glob.push((module_id, import_id));
+                        }
                     }
                 }
                 Some(ModuleDefId::AdtId(AdtId::EnumId(e))) => {
@@ -361,17 +393,14 @@ where
                     let resolutions = enum_data
                         .variants
                         .iter()
-                        .filter_map(|(local_id, variant_data)| {
+                        .map(|(local_id, variant_data)| {
                             let name = variant_data.name.clone();
                             let variant = EnumVariantId { parent: e, local_id };
-                            let res = Resolution {
-                                def: PerNs::both(variant.into(), variant.into()),
-                                import: Some(import_id),
-                            };
-                            Some((name, res))
+                            let res = PerNs::both(variant.into(), variant.into());
+                            (name, res)
                         })
                         .collect::<Vec<_>>();
-                    self.update(module_id, Some(import_id), &resolutions);
+                    self.update(module_id, &resolutions);
                 }
                 Some(d) => {
                     log::debug!("glob import {:?} from non-module/enum {:?}", import, d);
@@ -383,7 +412,7 @@ where
         } else {
             match import.path.segments.last() {
                 Some(last_segment) => {
-                    let name = import.alias.clone().unwrap_or_else(|| last_segment.name.clone());
+                    let name = import.alias.clone().unwrap_or_else(|| last_segment.clone());
                     log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
 
                     // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
@@ -393,62 +422,31 @@ where
                         }
                     }
 
-                    let resolution = Resolution { def, import: Some(import_id) };
-                    self.update(module_id, Some(import_id), &[(name, resolution)]);
+                    self.update(module_id, &[(name, def)]);
                 }
                 None => tested_by!(bogus_paths),
             }
         }
     }
 
-    fn update(
-        &mut self,
-        module_id: LocalModuleId,
-        import: Option<LocalImportId>,
-        resolutions: &[(Name, Resolution)],
-    ) {
-        self.update_recursive(module_id, import, resolutions, 0)
+    fn update(&mut self, module_id: LocalModuleId, resolutions: &[(Name, PerNs)]) {
+        self.update_recursive(module_id, resolutions, 0)
     }
 
     fn update_recursive(
         &mut self,
         module_id: LocalModuleId,
-        import: Option<LocalImportId>,
-        resolutions: &[(Name, Resolution)],
+        resolutions: &[(Name, PerNs)],
         depth: usize,
     ) {
         if depth > 100 {
             // prevent stack overflows (but this shouldn't be possible)
             panic!("infinite recursion in glob imports!");
         }
-        let module_items = &mut self.def_map.modules[module_id].scope;
+        let scope = &mut self.def_map.modules[module_id].scope;
         let mut changed = false;
         for (name, res) in resolutions {
-            let existing = module_items.items.entry(name.clone()).or_default();
-
-            if existing.def.types.is_none() && res.def.types.is_some() {
-                existing.def.types = res.def.types;
-                existing.import = import.or(res.import);
-                changed = true;
-            }
-            if existing.def.values.is_none() && res.def.values.is_some() {
-                existing.def.values = res.def.values;
-                existing.import = import.or(res.import);
-                changed = true;
-            }
-            if existing.def.macros.is_none() && res.def.macros.is_some() {
-                existing.def.macros = res.def.macros;
-                existing.import = import.or(res.import);
-                changed = true;
-            }
-
-            if existing.def.is_none()
-                && res.def.is_none()
-                && existing.import.is_none()
-                && res.import.is_some()
-            {
-                existing.import = res.import;
-            }
+            changed |= scope.push_res(name.clone(), *res);
         }
 
         if !changed {
@@ -461,27 +459,48 @@ where
             .flat_map(|v| v.iter())
             .cloned()
             .collect::<Vec<_>>();
-        for (glob_importing_module, glob_import) in glob_imports {
+        for (glob_importing_module, _glob_import) in glob_imports {
             // We pass the glob import so that the tracked import in those modules is that glob import
-            self.update_recursive(glob_importing_module, Some(glob_import), resolutions, depth + 1);
+            self.update_recursive(glob_importing_module, resolutions, depth + 1);
         }
     }
 
     fn resolve_macros(&mut self) -> ReachedFixedPoint {
         let mut macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new());
+        let mut attribute_macros =
+            std::mem::replace(&mut self.unexpanded_attribute_macros, Vec::new());
         let mut resolved = Vec::new();
         let mut res = ReachedFixedPoint::Yes;
-        macros.retain(|(module_id, ast_id, path)| {
+        macros.retain(|directive| {
+            if let Some(call_id) = directive.legacy {
+                res = ReachedFixedPoint::No;
+                resolved.push((directive.module_id, call_id));
+                return false;
+            }
+
             let resolved_res = self.def_map.resolve_path_fp_with_macro(
                 self.db,
                 ResolveMode::Other,
-                *module_id,
-                path,
+                directive.module_id,
+                &directive.path,
+                BuiltinShadowMode::Module,
             );
 
             if let Some(def) = resolved_res.resolved_def.take_macros() {
-                let call_id = def.as_call_id(self.db, *ast_id);
-                resolved.push((*module_id, call_id, def));
+                let call_id = def.as_call_id(self.db, MacroCallKind::FnLike(directive.ast_id));
+                resolved.push((directive.module_id, call_id));
+                res = ReachedFixedPoint::No;
+                return false;
+            }
+
+            true
+        });
+        attribute_macros.retain(|(module_id, ast_id, path)| {
+            let resolved_res = self.resolve_attribute_macro(path);
+
+            if let Some(def) = resolved_res {
+                let call_id = def.as_call_id(self.db, MacroCallKind::Attr(*ast_id));
+                resolved.push((*module_id, call_id));
                 res = ReachedFixedPoint::No;
                 return false;
             }
@@ -490,44 +509,41 @@ where
         });
 
         self.unexpanded_macros = macros;
+        self.unexpanded_attribute_macros = attribute_macros;
 
-        for (module_id, macro_call_id, macro_def_id) in resolved {
-            self.collect_macro_expansion(module_id, macro_call_id, macro_def_id);
+        for (module_id, macro_call_id) in resolved {
+            self.collect_macro_expansion(module_id, macro_call_id);
         }
 
         res
     }
 
-    fn collect_macro_expansion(
-        &mut self,
-        module_id: LocalModuleId,
-        macro_call_id: MacroCallId,
-        macro_def_id: MacroDefId,
-    ) {
-        if self.poison_macros.contains(&macro_def_id) {
-            return;
-        }
-
-        self.macro_stack_monitor.increase(macro_def_id);
-
-        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,
-                module_id,
-                raw_items: &raw_items,
-                mod_dir,
+    fn resolve_attribute_macro(&self, path: &ModPath) -> Option<MacroDefId> {
+        // FIXME this is currently super hacky, just enough to support the
+        // built-in derives
+        if let Some(name) = path.as_ident() {
+            // FIXME this should actually be handled with the normal name
+            // resolution; the std lib defines built-in stubs for the derives,
+            // but these are new-style `macro`s, which we don't support yet
+            if let Some(def_id) = find_builtin_derive(name) {
+                return Some(def_id);
             }
-            .collect(raw_items.items());
-        } else {
-            log::error!("Too deep macro expansion: {:?}", macro_call_id);
-            self.poison_macros.insert(macro_def_id);
         }
+        None
+    }
 
-        self.macro_stack_monitor.decrease(macro_def_id);
+    fn collect_macro_expansion(&mut self, module_id: LocalModuleId, macro_call_id: MacroCallId) {
+        let file_id: HirFileId = macro_call_id.as_file();
+        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,
+            module_id,
+            raw_items: &raw_items,
+            mod_dir,
+        }
+        .collect(raw_items.items());
     }
 
     fn finish(self) -> CrateDefMap {
@@ -581,20 +597,31 @@ where
                     raw::RawItemKind::Module(m) => {
                         self.collect_module(&self.raw_items[m], &item.attrs)
                     }
-                    raw::RawItemKind::Import(import_id) => self
-                        .def_collector
-                        .unresolved_imports
-                        .push((self.module_id, import_id, self.raw_items[import_id].clone())),
-                    raw::RawItemKind::Def(def) => self.define_def(&self.raw_items[def]),
+                    raw::RawItemKind::Import(import_id) => {
+                        self.def_collector.unresolved_imports.push(ImportDirective {
+                            module_id: self.module_id,
+                            import_id,
+                            import: self.raw_items[import_id].clone(),
+                            status: PartialResolvedImport::Unresolved,
+                        })
+                    }
+                    raw::RawItemKind::Def(def) => {
+                        self.define_def(&self.raw_items[def], &item.attrs)
+                    }
                     raw::RawItemKind::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
                     raw::RawItemKind::Impl(imp) => {
                         let module = ModuleId {
                             krate: self.def_collector.def_map.krate,
                             local_id: self.module_id,
                         };
-                        let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id);
-                        let imp_id = ImplId::from_ast_id(ctx, self.raw_items[imp].ast_id);
-                        self.def_collector.def_map.modules[self.module_id].impls.push(imp_id)
+                        let container = ContainerId::ModuleId(module);
+                        let ast_id = self.raw_items[imp].ast_id;
+                        let impl_id =
+                            ImplLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                                .intern(self.def_collector.db);
+                        self.def_collector.def_map.modules[self.module_id]
+                            .scope
+                            .define_impl(impl_id)
                     }
                 }
             }
@@ -667,72 +694,91 @@ where
         let modules = &mut self.def_collector.def_map.modules;
         let res = modules.alloc(ModuleData::default());
         modules[res].parent = Some(self.module_id);
-        modules[res].declaration = Some(declaration);
-        modules[res].definition = definition;
-        modules[res].scope.legacy_macros = modules[self.module_id].scope.legacy_macros.clone();
+        modules[res].origin = ModuleOrigin::not_sure_file(definition, declaration);
+        for (name, mac) in modules[self.module_id].scope.collect_legacy_macros() {
+            modules[res].scope.define_legacy_macro(name, mac)
+        }
         modules[self.module_id].children.insert(name.clone(), res);
-        let resolution = Resolution {
-            def: PerNs::types(
-                ModuleId { krate: self.def_collector.def_map.krate, local_id: res }.into(),
-            ),
-            import: None,
-        };
-        self.def_collector.update(self.module_id, None, &[(name, resolution)]);
+        let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: res };
+        let def: ModuleDefId = module.into();
+        self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
+        self.def_collector.update(self.module_id, &[(name, def.into())]);
         res
     }
 
-    fn define_def(&mut self, def: &raw::DefData) {
+    fn define_def(&mut self, def: &raw::DefData, attrs: &Attrs) {
         let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
-        let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id);
+        // FIXME: check attrs to see if this is an attribute macro invocation;
+        // in which case we don't add the invocation, just a single attribute
+        // macro invocation
 
-        let name = def.name.clone();
-        let def: PerNs = match def.kind {
-            raw::DefKind::Function(ast_id) => {
-                let def = FunctionLoc {
-                    container: ContainerId::ModuleId(module),
-                    ast_id: AstId::new(self.file_id, ast_id),
-                }
-                .intern(self.def_collector.db);
+        self.collect_derives(attrs, def);
 
-                PerNs::values(def.into())
+        let name = def.name.clone();
+        let container = ContainerId::ModuleId(module);
+        let def: ModuleDefId = match def.kind {
+            raw::DefKind::Function(ast_id) => FunctionLoc {
+                container: container.into(),
+                ast_id: AstId::new(self.file_id, ast_id),
             }
+            .intern(self.def_collector.db)
+            .into(),
             raw::DefKind::Struct(ast_id) => {
-                let id = StructId::from_ast_id(ctx, ast_id).into();
-                PerNs::both(id, id)
+                StructLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
             }
             raw::DefKind::Union(ast_id) => {
-                let id = UnionId::from_ast_id(ctx, ast_id).into();
-                PerNs::both(id, id)
+                UnionLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
+            }
+            raw::DefKind::Enum(ast_id) => {
+                EnumLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
             }
-            raw::DefKind::Enum(ast_id) => PerNs::types(EnumId::from_ast_id(ctx, ast_id).into()),
             raw::DefKind::Const(ast_id) => {
-                let def = ConstLoc {
-                    container: ContainerId::ModuleId(module),
-                    ast_id: AstId::new(self.file_id, ast_id),
-                }
-                .intern(self.def_collector.db);
-
-                PerNs::values(def.into())
+                ConstLoc { container: container.into(), ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
             }
             raw::DefKind::Static(ast_id) => {
-                let def = StaticLoc { container: module, ast_id: AstId::new(self.file_id, ast_id) }
-                    .intern(self.def_collector.db);
-
-                PerNs::values(def.into())
+                StaticLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
             }
-            raw::DefKind::Trait(ast_id) => PerNs::types(TraitId::from_ast_id(ctx, ast_id).into()),
-            raw::DefKind::TypeAlias(ast_id) => {
-                let def = TypeAliasLoc {
-                    container: ContainerId::ModuleId(module),
-                    ast_id: AstId::new(self.file_id, ast_id),
-                }
-                .intern(self.def_collector.db);
-
-                PerNs::types(def.into())
+            raw::DefKind::Trait(ast_id) => {
+                TraitLoc { container, ast_id: AstId::new(self.file_id, ast_id) }
+                    .intern(self.def_collector.db)
+                    .into()
             }
+            raw::DefKind::TypeAlias(ast_id) => TypeAliasLoc {
+                container: container.into(),
+                ast_id: AstId::new(self.file_id, ast_id),
+            }
+            .intern(self.def_collector.db)
+            .into(),
         };
-        let resolution = Resolution { def, import: None };
-        self.def_collector.update(self.module_id, None, &[(name, resolution)])
+        self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
+        self.def_collector.update(self.module_id, &[(name, def.into())])
+    }
+
+    fn collect_derives(&mut self, attrs: &Attrs, def: &raw::DefData) {
+        for derive_subtree in attrs.by_key("derive").tt_values() {
+            // for #[derive(Copy, Clone)], `derive_subtree` is the `(Copy, Clone)` subtree
+            for tt in &derive_subtree.token_trees {
+                let ident = match &tt {
+                    tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => ident,
+                    tt::TokenTree::Leaf(tt::Leaf::Punct(_)) => continue, // , is ok
+                    _ => continue, // anything else would be an error (which we currently ignore)
+                };
+                let path = ModPath::from_tt_ident(ident);
+
+                let ast_id = AstId::new(self.file_id, def.kind.ast_id());
+                self.def_collector.unexpanded_attribute_macros.push((self.module_id, ast_id, path));
+            }
+        }
     }
 
     fn collect_macro(&mut self, mac: &raw::MacroData) {
@@ -758,8 +804,8 @@ where
         if is_macro_rules(&mac.path) {
             if let Some(name) = &mac.name {
                 let macro_id = MacroDefId {
-                    ast_id,
-                    krate: self.def_collector.def_map.krate,
+                    ast_id: Some(ast_id),
+                    krate: Some(self.def_collector.def_map.krate),
                     kind: MacroDefKind::Declarative,
                 };
                 self.def_collector.define_macro(self.module_id, name.clone(), macro_id, mac.export);
@@ -767,14 +813,20 @@ where
             return;
         }
 
-        // Case 2: try to resolve in legacy scope and expand macro_rules, triggering
-        // recursive item collection.
+        // Case 2: try to resolve in legacy scope and expand macro_rules
         if let Some(macro_def) = mac.path.as_ident().and_then(|name| {
             self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
         }) {
-            let macro_call_id = macro_def.as_call_id(self.def_collector.db, ast_id);
+            let macro_call_id =
+                macro_def.as_call_id(self.def_collector.db, MacroCallKind::FnLike(ast_id));
+
+            self.def_collector.unexpanded_macros.push(MacroDirective {
+                module_id: self.module_id,
+                path: mac.path.clone(),
+                ast_id,
+                legacy: Some(macro_call_id),
+            });
 
-            self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, macro_def);
             return;
         }
 
@@ -782,13 +834,19 @@ where
         // We rewrite simple path `macro_name` to `self::macro_name` to force resolve in module scope only.
         let mut path = mac.path.clone();
         if path.is_ident() {
-            path.kind = PathKind::Self_;
+            path.kind = PathKind::Super(0);
         }
-        self.def_collector.unexpanded_macros.push((self.module_id, ast_id, path));
+
+        self.def_collector.unexpanded_macros.push(MacroDirective {
+            module_id: self.module_id,
+            path,
+            ast_id,
+            legacy: None,
+        });
     }
 
     fn import_all_legacy_macros(&mut self, module_id: LocalModuleId) {
-        let macros = self.def_collector.def_map[module_id].scope.legacy_macros.clone();
+        let macros = self.def_collector.def_map[module_id].scope.collect_legacy_macros();
         for (name, macro_) in macros {
             self.def_collector.define_legacy_macro(self.module_id, name.clone(), macro_);
         }
@@ -803,45 +861,35 @@ where
     }
 }
 
-fn is_macro_rules(path: &Path) -> bool {
-    path.as_ident() == Some(&name::MACRO_RULES)
+fn is_macro_rules(path: &ModPath) -> bool {
+    path.as_ident() == Some(&name![macro_rules])
 }
 
 #[cfg(test)]
 mod tests {
+    use crate::{db::DefDatabase, test_db::TestDB};
     use ra_arena::Arena;
     use ra_db::{fixture::WithFixture, SourceDatabase};
-    use rustc_hash::FxHashSet;
-
-    use crate::{db::DefDatabase, test_db::TestDB};
 
     use super::*;
 
-    fn do_collect_defs(
-        db: &impl DefDatabase,
-        def_map: CrateDefMap,
-        monitor: MacroStackMonitor,
-    ) -> (CrateDefMap, FxHashSet<MacroDefId>) {
+    fn do_collect_defs(db: &impl DefDatabase, def_map: CrateDefMap) -> CrateDefMap {
         let mut collector = DefCollector {
             db,
             def_map,
             glob_imports: FxHashMap::default(),
             unresolved_imports: Vec::new(),
+            resolved_imports: Vec::new(),
             unexpanded_macros: Vec::new(),
+            unexpanded_attribute_macros: Vec::new(),
             mod_dirs: FxHashMap::default(),
-            macro_stack_monitor: monitor,
-            poison_macros: FxHashSet::default(),
             cfg_options: &CfgOptions::default(),
         };
         collector.collect();
-        (collector.def_map, collector.poison_macros)
+        collector.def_map
     }
 
-    fn do_limited_resolve(
-        code: &str,
-        limit: u32,
-        poison_limit: u32,
-    ) -> (CrateDefMap, FxHashSet<MacroDefId>) {
+    fn do_resolve(code: &str) -> CrateDefMap {
         let (db, _file_id) = TestDB::with_single_file(&code);
         let krate = db.test_crate();
 
@@ -859,59 +907,18 @@ mod tests {
                 diagnostics: Vec::new(),
             }
         };
-
-        let mut monitor = MacroStackMonitor::default();
-        monitor.validator = Some(Box::new(move |count| {
-            assert!(count < limit);
-            count >= poison_limit
-        }));
-
-        do_collect_defs(&db, def_map, monitor)
+        do_collect_defs(&db, def_map)
     }
 
     #[test]
-    fn test_macro_expand_limit_width() {
-        do_limited_resolve(
+    fn test_macro_expand_will_stop() {
+        do_resolve(
             r#"
         macro_rules! foo {
             ($($ty:ty)*) => { foo!($($ty)*, $($ty)*); }
         }
 foo!(KABOOM);
         "#,
-            16,
-            1000,
         );
     }
-
-    #[test]
-    fn test_macro_expand_poisoned() {
-        let (_, poison_macros) = do_limited_resolve(
-            r#"
-        macro_rules! foo {
-            ($ty:ty) => { foo!($ty); }
-        }
-foo!(KABOOM);
-        "#,
-            100,
-            16,
-        );
-
-        assert_eq!(poison_macros.len(), 1);
-    }
-
-    #[test]
-    fn test_macro_expand_normal() {
-        let (_, poison_macros) = do_limited_resolve(
-            r#"
-        macro_rules! foo {
-            ($ident:ident) => { struct $ident {} }
-        }
-foo!(Bar);
-        "#,
-            16,
-            16,
-        );
-
-        assert_eq!(poison_macros.len(), 0);
-    }
 }
diff --git a/crates/ra_hir_def/src/nameres/path_resolution.rs b/crates/ra_hir_def/src/nameres/path_resolution.rs
index b72c55bd1..695014c7b 100644
--- a/crates/ra_hir_def/src/nameres/path_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/path_resolution.rs
@@ -10,16 +10,18 @@
 //!
 //! `ReachedFixedPoint` signals about this.
 
+use std::iter::successors;
+
 use hir_expand::name::Name;
 use ra_db::Edition;
 use test_utils::tested_by;
 
 use crate::{
     db::DefDatabase,
-    nameres::CrateDefMap,
-    path::{Path, PathKind},
+    nameres::{BuiltinShadowMode, CrateDefMap},
+    path::{ModPath, PathKind},
     per_ns::PerNs,
-    AdtId, EnumVariantId, LocalModuleId, ModuleDefId, ModuleId,
+    AdtId, CrateId, EnumVariantId, LocalModuleId, ModuleDefId, ModuleId,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -39,19 +41,21 @@ pub(super) struct ResolvePathResult {
     pub(super) resolved_def: PerNs,
     pub(super) segment_index: Option<usize>,
     pub(super) reached_fixedpoint: ReachedFixedPoint,
+    pub(super) krate: Option<CrateId>,
 }
 
 impl ResolvePathResult {
     fn empty(reached_fixedpoint: ReachedFixedPoint) -> ResolvePathResult {
-        ResolvePathResult::with(PerNs::none(), reached_fixedpoint, None)
+        ResolvePathResult::with(PerNs::none(), reached_fixedpoint, None, None)
     }
 
     fn with(
         resolved_def: PerNs,
         reached_fixedpoint: ReachedFixedPoint,
         segment_index: Option<usize>,
+        krate: Option<CrateId>,
     ) -> ResolvePathResult {
-        ResolvePathResult { resolved_def, reached_fixedpoint, segment_index }
+        ResolvePathResult { resolved_def, reached_fixedpoint, segment_index, krate }
     }
 }
 
@@ -67,8 +71,18 @@ impl CrateDefMap {
         db: &impl DefDatabase,
         mode: ResolveMode,
         original_module: LocalModuleId,
-        path: &Path,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
     ) -> ResolvePathResult {
+        // if it is not the last segment, we prefer the module to the builtin
+        let prefer_module = |index| {
+            if index == path.segments.len() - 1 {
+                shadow
+            } else {
+                BuiltinShadowMode::Module
+            }
+        };
+
         let mut segments = path.segments.iter().enumerate();
         let mut curr_per_ns: PerNs = match path.kind {
             PathKind::DollarCrate(krate) => {
@@ -85,9 +99,6 @@ impl CrateDefMap {
             PathKind::Crate => {
                 PerNs::types(ModuleId { krate: self.krate, local_id: self.root }.into())
             }
-            PathKind::Self_ => {
-                PerNs::types(ModuleId { krate: self.krate, local_id: original_module }.into())
-            }
             // plain import or absolute path in 2015: crate-relative with
             // fallback to extern prelude (with the simplification in
             // rust-lang/rust#57745)
@@ -96,24 +107,26 @@ impl CrateDefMap {
                 if self.edition == Edition::Edition2015
                     && (path.kind == PathKind::Abs || mode == ResolveMode::Import) =>
             {
-                let segment = match segments.next() {
-                    Some((_, segment)) => segment,
+                let (idx, segment) = match segments.next() {
+                    Some((idx, segment)) => (idx, segment),
                     None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                 };
                 log::debug!("resolving {:?} in crate root (+ extern prelude)", segment);
-                self.resolve_name_in_crate_root_or_extern_prelude(&segment.name)
+                self.resolve_name_in_crate_root_or_extern_prelude(&segment, prefer_module(idx))
             }
             PathKind::Plain => {
-                let segment = match segments.next() {
-                    Some((_, segment)) => segment,
+                let (idx, segment) = match segments.next() {
+                    Some((idx, segment)) => (idx, segment),
                     None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                 };
                 log::debug!("resolving {:?} in module", segment);
-                self.resolve_name_in_module(db, original_module, &segment.name)
+                self.resolve_name_in_module(db, original_module, &segment, prefer_module(idx))
             }
-            PathKind::Super => {
-                if let Some(p) = self.modules[original_module].parent {
-                    PerNs::types(ModuleId { krate: self.krate, local_id: p }.into())
+            PathKind::Super(lvl) => {
+                let m = successors(Some(original_module), |m| self.modules[*m].parent)
+                    .nth(lvl as usize);
+                if let Some(local_id) = m {
+                    PerNs::types(ModuleId { krate: self.krate, local_id }.into())
                 } else {
                     log::debug!("super path in root module");
                     return ResolvePathResult::empty(ReachedFixedPoint::Yes);
@@ -125,18 +138,13 @@ impl CrateDefMap {
                     Some((_, segment)) => segment,
                     None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                 };
-                if let Some(def) = self.extern_prelude.get(&segment.name) {
+                if let Some(def) = self.extern_prelude.get(&segment) {
                     log::debug!("absolute path {:?} resolved to crate {:?}", path, def);
                     PerNs::types(*def)
                 } else {
                     return ResolvePathResult::empty(ReachedFixedPoint::No); // extern crate declarations can add to the extern prelude
                 }
             }
-            PathKind::Type(_) => {
-                // This is handled in `infer::infer_path_expr`
-                // The result returned here does not matter
-                return ResolvePathResult::empty(ReachedFixedPoint::Yes);
-            }
         };
 
         for (i, segment) in segments {
@@ -156,32 +164,29 @@ impl CrateDefMap {
             curr_per_ns = match curr {
                 ModuleDefId::ModuleId(module) => {
                     if module.krate != self.krate {
-                        let path =
-                            Path { segments: path.segments[i..].to_vec(), kind: PathKind::Self_ };
+                        let path = ModPath {
+                            segments: path.segments[i..].to_vec(),
+                            kind: PathKind::Super(0),
+                        };
                         log::debug!("resolving {:?} in other crate", path);
                         let defp_map = db.crate_def_map(module.krate);
-                        let (def, s) = defp_map.resolve_path(db, module.local_id, &path);
+                        let (def, s) = defp_map.resolve_path(db, module.local_id, &path, shadow);
                         return ResolvePathResult::with(
                             def,
                             ReachedFixedPoint::Yes,
                             s.map(|s| s + i),
+                            Some(module.krate),
                         );
                     }
 
                     // Since it is a qualified path here, it should not contains legacy macros
-                    match self[module.local_id].scope.get(&segment.name) {
-                        Some(res) => res.def,
-                        _ => {
-                            log::debug!("path segment {:?} not found", segment.name);
-                            return ResolvePathResult::empty(ReachedFixedPoint::No);
-                        }
-                    }
+                    self[module.local_id].scope.get(&segment, prefer_module(i))
                 }
                 ModuleDefId::AdtId(AdtId::EnumId(e)) => {
                     // enum variant
                     tested_by!(can_import_enum_variant);
                     let enum_data = db.enum_data(e);
-                    match enum_data.variant(&segment.name) {
+                    match enum_data.variant(&segment) {
                         Some(local_id) => {
                             let variant = EnumVariantId { parent: e, local_id };
                             PerNs::both(variant.into(), variant.into())
@@ -191,6 +196,7 @@ impl CrateDefMap {
                                 PerNs::types(e.into()),
                                 ReachedFixedPoint::Yes,
                                 Some(i),
+                                Some(self.krate),
                             );
                         }
                     }
@@ -200,7 +206,7 @@ impl CrateDefMap {
                     // (`Struct::method`), or some other kind of associated item
                     log::debug!(
                         "path segment {:?} resolved to non-module {:?}, but is not last",
-                        segment.name,
+                        segment,
                         curr,
                     );
 
@@ -208,11 +214,13 @@ impl CrateDefMap {
                         PerNs::types(s),
                         ReachedFixedPoint::Yes,
                         Some(i),
+                        Some(self.krate),
                     );
                 }
             };
         }
-        ResolvePathResult::with(curr_per_ns, ReachedFixedPoint::Yes, None)
+
+        ResolvePathResult::with(curr_per_ns, ReachedFixedPoint::Yes, None, Some(self.krate))
     }
 
     fn resolve_name_in_module(
@@ -220,6 +228,7 @@ impl CrateDefMap {
         db: &impl DefDatabase,
         module: LocalModuleId,
         name: &Name,
+        shadow: BuiltinShadowMode,
     ) -> PerNs {
         // Resolve in:
         //  - legacy scope of macro
@@ -228,23 +237,31 @@ impl CrateDefMap {
         //  - std prelude
         let from_legacy_macro =
             self[module].scope.get_legacy_macro(name).map_or_else(PerNs::none, PerNs::macros);
-        let from_scope = self[module].scope.get(name).map_or_else(PerNs::none, |res| res.def);
+        let from_scope = self[module].scope.get(name, shadow);
         let from_extern_prelude =
             self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it));
-        let from_prelude = self.resolve_in_prelude(db, name);
+        let from_prelude = self.resolve_in_prelude(db, name, shadow);
 
         from_legacy_macro.or(from_scope).or(from_extern_prelude).or(from_prelude)
     }
 
-    fn resolve_name_in_crate_root_or_extern_prelude(&self, name: &Name) -> PerNs {
-        let from_crate_root =
-            self[self.root].scope.get(name).map_or_else(PerNs::none, |res| res.def);
+    fn resolve_name_in_crate_root_or_extern_prelude(
+        &self,
+        name: &Name,
+        shadow: BuiltinShadowMode,
+    ) -> PerNs {
+        let from_crate_root = self[self.root].scope.get(name, shadow);
         let from_extern_prelude = self.resolve_name_in_extern_prelude(name);
 
         from_crate_root.or(from_extern_prelude)
     }
 
-    fn resolve_in_prelude(&self, db: &impl DefDatabase, name: &Name) -> PerNs {
+    fn resolve_in_prelude(
+        &self,
+        db: &impl DefDatabase,
+        name: &Name,
+        shadow: BuiltinShadowMode,
+    ) -> PerNs {
         if let Some(prelude) = self.prelude {
             let keep;
             let def_map = if prelude.krate == self.krate {
@@ -254,7 +271,7 @@ impl CrateDefMap {
                 keep = db.crate_def_map(prelude.krate);
                 &keep
             };
-            def_map[prelude.local_id].scope.get(name).map_or_else(PerNs::none, |res| res.def)
+            def_map[prelude.local_id].scope.get(name, shadow)
         } else {
             PerNs::none()
         }
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 6eb106094..73dc08745 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -10,21 +10,18 @@ use std::{ops::Index, sync::Arc};
 use hir_expand::{
     ast_id_map::AstIdMap,
     db::AstDatabase,
-    either::Either,
     hygiene::Hygiene,
     name::{AsName, Name},
 };
-use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
+use ra_arena::{impl_arena_id, Arena, RawId};
+use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AttrsOwner, NameOwner},
-    AstNode, AstPtr,
+    AstNode,
 };
 use test_utils::tested_by;
 
-use crate::{
-    attr::Attrs, db::DefDatabase, path::Path, trace::Trace, FileAstId, HirFileId, LocalImportId,
-    Source,
-};
+use crate::{attr::Attrs, db::DefDatabase, path::ModPath, FileAstId, HirFileId, InFile};
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
 ///
@@ -33,7 +30,7 @@ use crate::{
 #[derive(Debug, Default, PartialEq, Eq)]
 pub struct RawItems {
     modules: Arena<Module, ModuleData>,
-    imports: Arena<LocalImportId, ImportData>,
+    imports: Arena<Import, ImportData>,
     defs: Arena<Def, DefData>,
     macros: Arena<Macro, MacroData>,
     impls: Arena<Impl, ImplData>,
@@ -41,35 +38,15 @@ pub struct RawItems {
     items: Vec<RawItem>,
 }
 
-#[derive(Debug, Default, PartialEq, Eq)]
-pub struct ImportSourceMap {
-    map: ArenaMap<LocalImportId, ImportSourcePtr>,
-}
-
-type ImportSourcePtr = Either<AstPtr<ast::UseTree>, AstPtr<ast::ExternCrateItem>>;
-
-impl ImportSourceMap {
-    pub fn get(&self, import: LocalImportId) -> ImportSourcePtr {
-        self.map[import].clone()
-    }
-}
-
 impl RawItems {
     pub(crate) fn raw_items_query(
         db: &(impl DefDatabase + AstDatabase),
         file_id: HirFileId,
     ) -> Arc<RawItems> {
-        db.raw_items_with_source_map(file_id).0
-    }
-
-    pub(crate) fn raw_items_with_source_map_query(
-        db: &(impl DefDatabase + AstDatabase),
-        file_id: HirFileId,
-    ) -> (Arc<RawItems>, Arc<ImportSourceMap>) {
+        let _p = profile("raw_items_query");
         let mut collector = RawItemsCollector {
             raw_items: RawItems::default(),
             source_ast_id_map: db.ast_id_map(file_id),
-            imports: Trace::new(),
             file_id,
             hygiene: Hygiene::new(db, file_id),
         };
@@ -80,11 +57,8 @@ impl RawItems {
                 collector.process_module(None, item_list);
             }
         }
-        let mut raw_items = collector.raw_items;
-        let (arena, map) = collector.imports.into_arena_and_map();
-        raw_items.imports = arena;
-        let source_map = ImportSourceMap { map };
-        (Arc::new(raw_items), Arc::new(source_map))
+        let raw_items = collector.raw_items;
+        Arc::new(raw_items)
     }
 
     pub(super) fn items(&self) -> &[RawItem] {
@@ -99,9 +73,9 @@ impl Index<Module> for RawItems {
     }
 }
 
-impl Index<LocalImportId> for RawItems {
+impl Index<Import> for RawItems {
     type Output = ImportData;
-    fn index(&self, idx: LocalImportId) -> &ImportData {
+    fn index(&self, idx: Import) -> &ImportData {
         &self.imports[idx]
     }
 }
@@ -136,7 +110,7 @@ pub(super) struct RawItem {
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub(super) enum RawItemKind {
     Module(Module),
-    Import(LocalImportId),
+    Import(Import),
     Def(Def),
     Macro(Macro),
     Impl(Impl),
@@ -152,9 +126,13 @@ pub(super) enum ModuleData {
     Definition { name: Name, ast_id: FileAstId<ast::Module>, items: Vec<RawItem> },
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct Import(RawId);
+impl_arena_id!(Import);
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ImportData {
-    pub(super) path: Path,
+    pub(super) path: ModPath,
     pub(super) alias: Option<Name>,
     pub(super) is_glob: bool,
     pub(super) is_prelude: bool,
@@ -184,6 +162,21 @@ pub(super) enum DefKind {
     TypeAlias(FileAstId<ast::TypeAliasDef>),
 }
 
+impl DefKind {
+    pub fn ast_id(&self) -> FileAstId<ast::ModuleItem> {
+        match self {
+            DefKind::Function(it) => it.upcast(),
+            DefKind::Struct(it) => it.upcast(),
+            DefKind::Union(it) => it.upcast(),
+            DefKind::Enum(it) => it.upcast(),
+            DefKind::Const(it) => it.upcast(),
+            DefKind::Static(it) => it.upcast(),
+            DefKind::Trait(it) => it.upcast(),
+            DefKind::TypeAlias(it) => it.upcast(),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub(super) struct Macro(RawId);
 impl_arena_id!(Macro);
@@ -191,7 +184,7 @@ impl_arena_id!(Macro);
 #[derive(Debug, PartialEq, Eq)]
 pub(super) struct MacroData {
     pub(super) ast_id: FileAstId<ast::MacroCall>,
-    pub(super) path: Path,
+    pub(super) path: ModPath,
     pub(super) name: Option<Name>,
     pub(super) export: bool,
     pub(super) builtin: bool,
@@ -208,7 +201,6 @@ pub(super) struct ImplData {
 
 struct RawItemsCollector {
     raw_items: RawItems,
-    imports: Trace<LocalImportId, ImportData, ImportSourcePtr>,
     source_ast_id_map: Arc<AstIdMap>,
     file_id: HirFileId,
     hygiene: Hygiene,
@@ -312,10 +304,10 @@ impl RawItemsCollector {
         let attrs = self.parse_attrs(&use_item);
 
         let mut buf = Vec::new();
-        Path::expand_use_item(
-            Source { value: use_item, file_id: self.file_id },
+        ModPath::expand_use_item(
+            InFile { value: use_item, file_id: self.file_id },
             &self.hygiene,
-            |path, use_tree, is_glob, alias| {
+            |path, _use_tree, is_glob, alias| {
                 let import_data = ImportData {
                     path,
                     alias,
@@ -324,11 +316,11 @@ impl RawItemsCollector {
                     is_extern_crate: false,
                     is_macro_use: false,
                 };
-                buf.push((import_data, Either::A(AstPtr::new(use_tree))));
+                buf.push(import_data);
             },
         );
-        for (import_data, ptr) in buf {
-            self.push_import(current_module, attrs.clone(), import_data, ptr);
+        for import_data in buf {
+            self.push_import(current_module, attrs.clone(), import_data);
         }
     }
 
@@ -338,7 +330,7 @@ impl RawItemsCollector {
         extern_crate: ast::ExternCrateItem,
     ) {
         if let Some(name_ref) = extern_crate.name_ref() {
-            let path = Path::from_name_ref(&name_ref);
+            let path = ModPath::from_name_ref(&name_ref);
             let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
             let attrs = self.parse_attrs(&extern_crate);
             // FIXME: cfg_attr
@@ -351,18 +343,13 @@ impl RawItemsCollector {
                 is_extern_crate: true,
                 is_macro_use,
             };
-            self.push_import(
-                current_module,
-                attrs,
-                import_data,
-                Either::B(AstPtr::new(&extern_crate)),
-            );
+            self.push_import(current_module, attrs, import_data);
         }
     }
 
     fn add_macro(&mut self, current_module: Option<Module>, m: ast::MacroCall) {
         let attrs = self.parse_attrs(&m);
-        let path = match m.path().and_then(|path| Path::from_src(path, &self.hygiene)) {
+        let path = match m.path().and_then(|path| ModPath::from_src(path, &self.hygiene)) {
             Some(it) => it,
             _ => return,
         };
@@ -387,14 +374,8 @@ impl RawItemsCollector {
         self.push_item(current_module, attrs, RawItemKind::Impl(imp))
     }
 
-    fn push_import(
-        &mut self,
-        current_module: Option<Module>,
-        attrs: Attrs,
-        data: ImportData,
-        source: ImportSourcePtr,
-    ) {
-        let import = self.imports.alloc(|| source, || data);
+    fn push_import(&mut self, current_module: Option<Module>, attrs: Attrs, data: ImportData) {
+        let import = self.raw_items.imports.alloc(data);
         self.push_item(current_module, attrs, RawItemKind::Import(import))
     }
 
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index 87fcd617c..ff474b53b 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -32,27 +32,22 @@ fn render_crate_def_map(map: &CrateDefMap) -> String {
         *buf += path;
         *buf += "\n";
 
-        let mut entries = map.modules[module]
-            .scope
-            .items
-            .iter()
-            .map(|(name, res)| (name, res.def))
-            .collect::<Vec<_>>();
-        entries.sort_by_key(|(name, _)| *name);
-
-        for (name, res) in entries {
+        let mut entries = map.modules[module].scope.collect_resolutions();
+        entries.sort_by_key(|(name, _)| name.clone());
+
+        for (name, def) in entries {
             *buf += &format!("{}:", name);
 
-            if res.types.is_some() {
+            if def.types.is_some() {
                 *buf += " t";
             }
-            if res.values.is_some() {
+            if def.values.is_some() {
                 *buf += " v";
             }
-            if res.macros.is_some() {
+            if def.macros.is_some() {
                 *buf += " m";
             }
-            if res.is_none() {
+            if def.is_none() {
                 *buf += " _";
             }
 
@@ -558,3 +553,35 @@ fn cfg_test() {
         ⋮Foo: t v
     "###);
 }
+
+#[test]
+fn infer_multiple_namespace() {
+    let map = def_map(
+        r#"
+//- /main.rs
+mod a {
+    pub type T = ();
+    pub use crate::b::*;
+}
+
+use crate::a::T;
+
+mod b {
+    pub const T: () = ();
+}
+"#,
+    );
+
+    assert_snapshot!(map, @r###"
+    ⋮crate
+    ⋮T: t v
+    ⋮a: t
+    ⋮b: t
+    ⋮
+    ⋮crate::b
+    ⋮T: v
+    ⋮
+    ⋮crate::a
+    ⋮T: t v
+"###);
+}
diff --git a/crates/ra_hir_def/src/nameres/tests/globs.rs b/crates/ra_hir_def/src/nameres/tests/globs.rs
index 5b03fe365..5e24cb94d 100644
--- a/crates/ra_hir_def/src/nameres/tests/globs.rs
+++ b/crates/ra_hir_def/src/nameres/tests/globs.rs
@@ -112,3 +112,24 @@ fn glob_enum() {
     "###
     );
 }
+
+#[test]
+fn glob_enum_group() {
+    covers!(glob_enum_group);
+    let map = def_map(
+        "
+        //- /lib.rs
+        enum Foo {
+            Bar, Baz
+        }
+        use self::Foo::{*};
+        ",
+    );
+    assert_snapshot!(map, @r###"
+   ⋮crate
+   ⋮Bar: t v
+   ⋮Baz: t v
+   ⋮Foo: t
+    "###
+    );
+}
diff --git a/crates/ra_hir_def/src/nameres/tests/incremental.rs b/crates/ra_hir_def/src/nameres/tests/incremental.rs
index 903a22771..ef2e9435c 100644
--- a/crates/ra_hir_def/src/nameres/tests/incremental.rs
+++ b/crates/ra_hir_def/src/nameres/tests/incremental.rs
@@ -116,7 +116,7 @@ fn typing_inside_a_macro_should_not_invalidate_def_map() {
         let events = db.log_executed(|| {
             let crate_def_map = db.crate_def_map(krate);
             let (_, module_data) = crate_def_map.modules.iter().last().unwrap();
-            assert_eq!(module_data.scope.items.len(), 1);
+            assert_eq!(module_data.scope.collect_resolutions().len(), 1);
         });
         assert!(format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
     }
@@ -126,7 +126,7 @@ fn typing_inside_a_macro_should_not_invalidate_def_map() {
         let events = db.log_executed(|| {
             let crate_def_map = db.crate_def_map(krate);
             let (_, module_data) = crate_def_map.modules.iter().last().unwrap();
-            assert_eq!(module_data.scope.items.len(), 1);
+            assert_eq!(module_data.scope.collect_resolutions().len(), 1);
         });
         assert!(!format!("{:?}", events).contains("crate_def_map"), "{:#?}", events)
     }
diff --git a/crates/ra_hir_def/src/nameres/tests/macros.rs b/crates/ra_hir_def/src/nameres/tests/macros.rs
index 704065633..d104f5993 100644
--- a/crates/ra_hir_def/src/nameres/tests/macros.rs
+++ b/crates/ra_hir_def/src/nameres/tests/macros.rs
@@ -600,3 +600,27 @@ fn macro_dollar_crate_is_correct_in_indirect_deps() {
         ⋮bar: t v
     "###);
 }
+
+#[test]
+fn expand_derive() {
+    let map = compute_crate_def_map(
+        "
+        //- /main.rs
+        #[derive(Clone)]
+        struct Foo;
+        ",
+    );
+    assert_eq!(map.modules[map.root].scope.impls().len(), 1);
+}
+
+#[test]
+fn expand_multiple_derive() {
+    let map = compute_crate_def_map(
+        "
+        //- /main.rs
+        #[derive(Copy, Clone)]
+        struct Foo;
+        ",
+    );
+    assert_eq!(map.modules[map.root].scope.impls().len(), 2);
+}
diff --git a/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs b/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
index e11530062..e800cc68e 100644
--- a/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/tests/mod_resolution.rs
@@ -668,7 +668,7 @@ fn unresolved_module_diagnostics() {
             module: LocalModuleId(
                 0,
             ),
-            declaration: AstId {
+            declaration: InFile {
                 file_id: HirFileId(
                     FileId(
                         FileId(
@@ -676,7 +676,7 @@ fn unresolved_module_diagnostics() {
                         ),
                     ),
                 ),
-                file_ast_id: FileAstId {
+                value: FileAstId {
                     raw: ErasedFileAstId(
                         1,
                     ),
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index 6810a26db..8e1294201 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -1,35 +1,97 @@
 //! A desugared representation of paths like `crate::foo` or `<Type as Trait>::bar`.
+mod lower;
 
 use std::{iter, sync::Arc};
 
 use hir_expand::{
-    either::Either,
     hygiene::Hygiene,
-    name::{self, AsName, Name},
+    name::{AsName, Name},
 };
 use ra_db::CrateId;
-use ra_syntax::{
-    ast::{self, NameOwner, TypeAscriptionOwner},
-    AstNode,
-};
+use ra_syntax::ast;
 
-use crate::{type_ref::TypeRef, Source};
+use crate::{type_ref::TypeRef, InFile};
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct Path {
+pub struct ModPath {
     pub kind: PathKind,
-    pub segments: Vec<PathSegment>,
+    pub segments: Vec<Name>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct PathSegment {
-    pub name: Name,
-    pub args_and_bindings: Option<Arc<GenericArgs>>,
+pub enum PathKind {
+    Plain,
+    /// `self::` is `Super(0)`
+    Super(u8),
+    Crate,
+    /// Absolute path (::foo)
+    Abs,
+    /// `$crate` from macro expansion
+    DollarCrate(CrateId),
+}
+
+impl ModPath {
+    pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<ModPath> {
+        lower::lower_path(path, hygiene).map(|it| it.mod_path)
+    }
+
+    pub fn from_simple_segments(
+        kind: PathKind,
+        segments: impl IntoIterator<Item = Name>,
+    ) -> ModPath {
+        let segments = segments.into_iter().collect::<Vec<_>>();
+        ModPath { kind, segments }
+    }
+
+    pub(crate) fn from_name_ref(name_ref: &ast::NameRef) -> ModPath {
+        name_ref.as_name().into()
+    }
+
+    /// Converts an `tt::Ident` into a single-identifier `Path`.
+    pub(crate) fn from_tt_ident(ident: &tt::Ident) -> ModPath {
+        ident.as_name().into()
+    }
+
+    /// Calls `cb` with all paths, represented by this use item.
+    pub(crate) fn expand_use_item(
+        item_src: InFile<ast::UseItem>,
+        hygiene: &Hygiene,
+        mut cb: impl FnMut(ModPath, &ast::UseTree, /* is_glob */ bool, Option<Name>),
+    ) {
+        if let Some(tree) = item_src.value.use_tree() {
+            lower::lower_use_tree(None, tree, hygiene, &mut cb);
+        }
+    }
+
+    pub fn is_ident(&self) -> bool {
+        self.kind == PathKind::Plain && self.segments.len() == 1
+    }
+
+    pub fn is_self(&self) -> bool {
+        self.kind == PathKind::Super(0) && self.segments.is_empty()
+    }
+
+    /// If this path is a single identifier, like `foo`, return its name.
+    pub fn as_ident(&self) -> Option<&Name> {
+        if self.kind != PathKind::Plain || self.segments.len() > 1 {
+            return None;
+        }
+        self.segments.first()
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Path {
+    /// Type based path like `<T>::foo`.
+    /// Note that paths like `<Type as Trait>::foo` are desugard to `Trait::<Self=Type>::foo`.
+    type_anchor: Option<Box<TypeRef>>,
+    mod_path: ModPath,
+    /// Invariant: the same len as self.path.segments
+    generic_args: Vec<Option<Arc<GenericArgs>>>,
 }
 
 /// Generic arguments to a path segment (e.g. the `i32` in `Option<i32>`). This
-/// can (in the future) also include bindings of associated types, like in
-/// `Iterator<Item = Foo>`.
+/// also includes bindings of associated types, like in `Iterator<Item = Foo>`.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct GenericArgs {
     pub args: Vec<GenericArg>,
@@ -50,234 +112,111 @@ pub enum GenericArg {
     // or lifetime...
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum PathKind {
-    Plain,
-    Self_,
-    Super,
-    Crate,
-    // Absolute path
-    Abs,
-    // Type based path like `<T>::foo`
-    Type(Box<TypeRef>),
-    // `$crate` from macro expansion
-    DollarCrate(CrateId),
-}
-
 impl Path {
-    /// Calls `cb` with all paths, represented by this use item.
-    pub(crate) fn expand_use_item(
-        item_src: Source<ast::UseItem>,
-        hygiene: &Hygiene,
-        mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
-    ) {
-        if let Some(tree) = item_src.value.use_tree() {
-            expand_use_tree(None, tree, hygiene, &mut cb);
-        }
-    }
-
-    pub(crate) fn from_simple_segments(
-        kind: PathKind,
-        segments: impl IntoIterator<Item = Name>,
-    ) -> Path {
-        Path {
-            kind,
-            segments: segments
-                .into_iter()
-                .map(|name| PathSegment { name, args_and_bindings: None })
-                .collect(),
-        }
-    }
-
     /// Converts an `ast::Path` to `Path`. Works with use trees.
     /// DEPRECATED: It does not handle `$crate` from macro call.
     pub fn from_ast(path: ast::Path) -> Option<Path> {
-        Path::from_src(path, &Hygiene::new_unhygienic())
+        lower::lower_path(path, &Hygiene::new_unhygienic())
     }
 
     /// Converts an `ast::Path` to `Path`. Works with use trees.
     /// It correctly handles `$crate` based path from macro call.
-    pub fn from_src(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
-        let mut kind = PathKind::Plain;
-        let mut segments = Vec::new();
-        loop {
-            let segment = path.segment()?;
-
-            if segment.has_colon_colon() {
-                kind = PathKind::Abs;
-            }
-
-            match segment.kind()? {
-                ast::PathSegmentKind::Name(name_ref) => {
-                    // FIXME: this should just return name
-                    match hygiene.name_ref_to_name(name_ref) {
-                        Either::A(name) => {
-                            let args = segment
-                                .type_arg_list()
-                                .and_then(GenericArgs::from_ast)
-                                .or_else(|| {
-                                    GenericArgs::from_fn_like_path_ast(
-                                        segment.param_list(),
-                                        segment.ret_type(),
-                                    )
-                                })
-                                .map(Arc::new);
-                            let segment = PathSegment { name, args_and_bindings: args };
-                            segments.push(segment);
-                        }
-                        Either::B(crate_id) => {
-                            kind = PathKind::DollarCrate(crate_id);
-                            break;
-                        }
-                    }
-                }
-                ast::PathSegmentKind::Type { type_ref, trait_ref } => {
-                    assert!(path.qualifier().is_none()); // this can only occur at the first segment
-
-                    let self_type = TypeRef::from_ast(type_ref?);
-
-                    match trait_ref {
-                        // <T>::foo
-                        None => {
-                            kind = PathKind::Type(Box::new(self_type));
-                        }
-                        // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
-                        Some(trait_ref) => {
-                            let path = Path::from_src(trait_ref.path()?, hygiene)?;
-                            kind = path.kind;
-                            let mut prefix_segments = path.segments;
-                            prefix_segments.reverse();
-                            segments.extend(prefix_segments);
-                            // Insert the type reference (T in the above example) as Self parameter for the trait
-                            let mut last_segment = segments.last_mut()?;
-                            if last_segment.args_and_bindings.is_none() {
-                                last_segment.args_and_bindings =
-                                    Some(Arc::new(GenericArgs::empty()));
-                            };
-                            let args = last_segment.args_and_bindings.as_mut().unwrap();
-                            let mut args_inner = Arc::make_mut(args);
-                            args_inner.has_self_type = true;
-                            args_inner.args.insert(0, GenericArg::Type(self_type));
-                        }
-                    }
-                }
-                ast::PathSegmentKind::CrateKw => {
-                    kind = PathKind::Crate;
-                    break;
-                }
-                ast::PathSegmentKind::SelfKw => {
-                    kind = PathKind::Self_;
-                    break;
-                }
-                ast::PathSegmentKind::SuperKw => {
-                    kind = PathKind::Super;
-                    break;
-                }
-            }
-            path = match qualifier(&path) {
-                Some(it) => it,
-                None => break,
-            };
-        }
-        segments.reverse();
-        return Some(Path { kind, segments });
-
-        fn qualifier(path: &ast::Path) -> Option<ast::Path> {
-            if let Some(q) = path.qualifier() {
-                return Some(q);
-            }
-            // FIXME: this bottom up traversal is not too precise.
-            // Should we handle do a top-down analysis, recording results?
-            let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
-            let use_tree = use_tree_list.parent_use_tree();
-            use_tree.path()
-        }
+    pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
+        lower::lower_path(path, hygiene)
     }
 
     /// Converts an `ast::NameRef` into a single-identifier `Path`.
     pub(crate) fn from_name_ref(name_ref: &ast::NameRef) -> Path {
-        name_ref.as_name().into()
+        Path { type_anchor: None, mod_path: name_ref.as_name().into(), generic_args: vec![None] }
     }
 
-    /// `true` is this path is a single identifier, like `foo`
-    pub fn is_ident(&self) -> bool {
-        self.kind == PathKind::Plain && self.segments.len() == 1
+    pub fn kind(&self) -> &PathKind {
+        &self.mod_path.kind
     }
 
-    /// `true` if this path is just a standalone `self`
-    pub fn is_self(&self) -> bool {
-        self.kind == PathKind::Self_ && self.segments.is_empty()
+    pub fn type_anchor(&self) -> Option<&TypeRef> {
+        self.type_anchor.as_deref()
     }
 
-    /// If this path is a single identifier, like `foo`, return its name.
-    pub fn as_ident(&self) -> Option<&Name> {
-        if self.kind != PathKind::Plain || self.segments.len() > 1 {
-            return None;
+    pub fn segments(&self) -> PathSegments<'_> {
+        PathSegments {
+            segments: self.mod_path.segments.as_slice(),
+            generic_args: self.generic_args.as_slice(),
         }
-        self.segments.first().map(|s| &s.name)
     }
 
-    pub fn expand_macro_expr(&self) -> Option<Name> {
-        self.as_ident().and_then(|name| Some(name.clone()))
+    pub fn mod_path(&self) -> &ModPath {
+        &self.mod_path
     }
 
-    pub fn is_type_relative(&self) -> bool {
-        match self.kind {
-            PathKind::Type(_) => true,
-            _ => false,
+    pub fn qualifier(&self) -> Option<Path> {
+        if self.mod_path.is_ident() {
+            return None;
         }
+        let res = Path {
+            type_anchor: self.type_anchor.clone(),
+            mod_path: ModPath {
+                kind: self.mod_path.kind.clone(),
+                segments: self.mod_path.segments[..self.mod_path.segments.len() - 1].to_vec(),
+            },
+            generic_args: self.generic_args[..self.generic_args.len() - 1].to_vec(),
+        };
+        Some(res)
     }
 }
 
-impl GenericArgs {
-    pub(crate) fn from_ast(node: ast::TypeArgList) -> Option<GenericArgs> {
-        let mut args = Vec::new();
-        for type_arg in node.type_args() {
-            let type_ref = TypeRef::from_ast_opt(type_arg.type_ref());
-            args.push(GenericArg::Type(type_ref));
-        }
-        // lifetimes ignored for now
-        let mut bindings = Vec::new();
-        for assoc_type_arg in node.assoc_type_args() {
-            if let Some(name_ref) = assoc_type_arg.name_ref() {
-                let name = name_ref.as_name();
-                let type_ref = TypeRef::from_ast_opt(assoc_type_arg.type_ref());
-                bindings.push((name, type_ref));
-            }
-        }
-        if args.is_empty() && bindings.is_empty() {
-            None
-        } else {
-            Some(GenericArgs { args, has_self_type: false, bindings })
-        }
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct PathSegment<'a> {
+    pub name: &'a Name,
+    pub args_and_bindings: Option<&'a GenericArgs>,
+}
+
+pub struct PathSegments<'a> {
+    segments: &'a [Name],
+    generic_args: &'a [Option<Arc<GenericArgs>>],
+}
+
+impl<'a> PathSegments<'a> {
+    pub const EMPTY: PathSegments<'static> = PathSegments { segments: &[], generic_args: &[] };
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+    pub fn len(&self) -> usize {
+        self.segments.len()
+    }
+    pub fn first(&self) -> Option<PathSegment<'a>> {
+        self.get(0)
+    }
+    pub fn last(&self) -> Option<PathSegment<'a>> {
+        self.get(self.len().checked_sub(1)?)
+    }
+    pub fn get(&self, idx: usize) -> Option<PathSegment<'a>> {
+        assert_eq!(self.segments.len(), self.generic_args.len());
+        let res = PathSegment {
+            name: self.segments.get(idx)?,
+            args_and_bindings: self.generic_args.get(idx).unwrap().as_ref().map(|it| &**it),
+        };
+        Some(res)
+    }
+    pub fn skip(&self, len: usize) -> PathSegments<'a> {
+        assert_eq!(self.segments.len(), self.generic_args.len());
+        PathSegments { segments: &self.segments[len..], generic_args: &self.generic_args[len..] }
+    }
+    pub fn take(&self, len: usize) -> PathSegments<'a> {
+        assert_eq!(self.segments.len(), self.generic_args.len());
+        PathSegments { segments: &self.segments[..len], generic_args: &self.generic_args[..len] }
+    }
+    pub fn iter(&self) -> impl Iterator<Item = PathSegment<'a>> {
+        self.segments.iter().zip(self.generic_args.iter()).map(|(name, args)| PathSegment {
+            name,
+            args_and_bindings: args.as_ref().map(|it| &**it),
+        })
     }
+}
 
-    /// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
-    /// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
-    pub(crate) fn from_fn_like_path_ast(
-        params: Option<ast::ParamList>,
-        ret_type: Option<ast::RetType>,
-    ) -> Option<GenericArgs> {
-        let mut args = Vec::new();
-        let mut bindings = Vec::new();
-        if let Some(params) = params {
-            let mut param_types = Vec::new();
-            for param in params.params() {
-                let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
-                param_types.push(type_ref);
-            }
-            let arg = GenericArg::Type(TypeRef::Tuple(param_types));
-            args.push(arg);
-        }
-        if let Some(ret_type) = ret_type {
-            let type_ref = TypeRef::from_ast_opt(ret_type.type_ref());
-            bindings.push((name::OUTPUT_TYPE, type_ref))
-        }
-        if args.is_empty() && bindings.is_empty() {
-            None
-        } else {
-            Some(GenericArgs { args, has_self_type: false, bindings })
-        }
+impl GenericArgs {
+    pub(crate) fn from_ast(node: ast::TypeArgList) -> Option<GenericArgs> {
+        lower::lower_generic_args(node)
     }
 
     pub(crate) fn empty() -> GenericArgs {
@@ -287,137 +226,51 @@ impl GenericArgs {
 
 impl From<Name> for Path {
     fn from(name: Name) -> Path {
-        Path::from_simple_segments(PathKind::Plain, iter::once(name))
+        Path {
+            type_anchor: None,
+            mod_path: ModPath::from_simple_segments(PathKind::Plain, iter::once(name)),
+            generic_args: vec![None],
+        }
     }
 }
 
-fn expand_use_tree(
-    prefix: Option<Path>,
-    tree: ast::UseTree,
-    hygiene: &Hygiene,
-    cb: &mut dyn FnMut(Path, &ast::UseTree, bool, Option<Name>),
-) {
-    if let Some(use_tree_list) = tree.use_tree_list() {
-        let prefix = match tree.path() {
-            // E.g. use something::{{{inner}}};
-            None => prefix,
-            // E.g. `use something::{inner}` (prefix is `None`, path is `something`)
-            // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
-            Some(path) => match convert_path(prefix, path, hygiene) {
-                Some(it) => Some(it),
-                None => return, // FIXME: report errors somewhere
-            },
-        };
-        for child_tree in use_tree_list.use_trees() {
-            expand_use_tree(prefix.clone(), child_tree, hygiene, cb);
-        }
-    } else {
-        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
-        if let Some(ast_path) = tree.path() {
-            // Handle self in a path.
-            // E.g. `use something::{self, <...>}`
-            if ast_path.qualifier().is_none() {
-                if let Some(segment) = ast_path.segment() {
-                    if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
-                        if let Some(prefix) = prefix {
-                            cb(prefix, &tree, false, alias);
-                            return;
-                        }
-                    }
-                }
-            }
-            if let Some(path) = convert_path(prefix, ast_path, hygiene) {
-                let is_glob = tree.has_star();
-                cb(path, &tree, is_glob, alias)
-            }
-            // FIXME: report errors somewhere
-            // We get here if we do
-        }
+impl From<Name> for ModPath {
+    fn from(name: Name) -> ModPath {
+        ModPath::from_simple_segments(PathKind::Plain, iter::once(name))
     }
 }
 
-fn convert_path(prefix: Option<Path>, path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
-    let prefix = if let Some(qual) = path.qualifier() {
-        Some(convert_path(prefix, qual, hygiene)?)
-    } else {
-        prefix
-    };
-
-    let segment = path.segment()?;
-    let res = match segment.kind()? {
-        ast::PathSegmentKind::Name(name_ref) => {
-            match hygiene.name_ref_to_name(name_ref) {
-                Either::A(name) => {
-                    // no type args in use
-                    let mut res = prefix.unwrap_or_else(|| Path {
-                        kind: PathKind::Plain,
-                        segments: Vec::with_capacity(1),
-                    });
-                    res.segments.push(PathSegment {
-                        name,
-                        args_and_bindings: None, // no type args in use
-                    });
-                    res
-                }
-                Either::B(crate_id) => {
-                    return Some(Path::from_simple_segments(
-                        PathKind::DollarCrate(crate_id),
-                        iter::empty(),
-                    ))
-                }
-            }
-        }
-        ast::PathSegmentKind::CrateKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Crate, iter::empty())
-        }
-        ast::PathSegmentKind::SelfKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Self_, iter::empty())
-        }
-        ast::PathSegmentKind::SuperKw => {
-            if prefix.is_some() {
-                return None;
-            }
-            Path::from_simple_segments(PathKind::Super, iter::empty())
-        }
-        ast::PathSegmentKind::Type { .. } => {
-            // not allowed in imports
-            return None;
-        }
+pub use hir_expand::name as __name;
+
+#[macro_export]
+macro_rules! __known_path {
+    (std::iter::IntoIterator) => {};
+    (std::result::Result) => {};
+    (std::ops::Range) => {};
+    (std::ops::RangeFrom) => {};
+    (std::ops::RangeFull) => {};
+    (std::ops::RangeTo) => {};
+    (std::ops::RangeToInclusive) => {};
+    (std::ops::RangeInclusive) => {};
+    (std::boxed::Box) => {};
+    (std::future::Future) => {};
+    (std::ops::Try) => {};
+    (std::ops::Neg) => {};
+    (std::ops::Not) => {};
+    (std::ops::Index) => {};
+    ($path:path) => {
+        compile_error!("Please register your known path in the path module")
     };
-    Some(res)
 }
 
-pub mod known {
-    use hir_expand::name;
-
-    use super::{Path, PathKind};
-
-    pub fn std_iter_into_iterator() -> Path {
-        Path::from_simple_segments(
-            PathKind::Abs,
-            vec![name::STD, name::ITER, name::INTO_ITERATOR_TYPE],
-        )
-    }
-
-    pub fn std_ops_try() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::OPS, name::TRY_TYPE])
-    }
-
-    pub fn std_result_result() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::RESULT, name::RESULT_TYPE])
-    }
-
-    pub fn std_future_future() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::FUTURE, name::FUTURE_TYPE])
-    }
-
-    pub fn std_boxed_box() -> Path {
-        Path::from_simple_segments(PathKind::Abs, vec![name::STD, name::BOXED, name::BOX_TYPE])
-    }
+#[macro_export]
+macro_rules! __path {
+    ($start:ident $(:: $seg:ident)*) => ({
+        $crate::__known_path!($start $(:: $seg)*);
+        $crate::path::ModPath::from_simple_segments($crate::path::PathKind::Abs, vec![
+            $crate::path::__name![$start], $($crate::path::__name![$seg],)*
+        ])
+    });
 }
+
+pub use crate::__path as path;
diff --git a/crates/ra_hir_def/src/path/lower.rs b/crates/ra_hir_def/src/path/lower.rs
new file mode 100644
index 000000000..62aafd508
--- /dev/null
+++ b/crates/ra_hir_def/src/path/lower.rs
@@ -0,0 +1,178 @@
+//! Transforms syntax into `Path` objects, ideally with accounting for hygiene
+
+mod lower_use;
+
+use std::sync::Arc;
+
+use either::Either;
+use hir_expand::{
+    hygiene::Hygiene,
+    name::{name, AsName},
+};
+use ra_syntax::ast::{self, AstNode, TypeAscriptionOwner};
+
+use crate::{
+    path::{GenericArg, GenericArgs, ModPath, Path, PathKind},
+    type_ref::TypeRef,
+};
+
+pub(super) use lower_use::lower_use_tree;
+
+/// Converts an `ast::Path` to `Path`. Works with use trees.
+/// It correctly handles `$crate` based path from macro call.
+pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
+    let mut kind = PathKind::Plain;
+    let mut type_anchor = None;
+    let mut segments = Vec::new();
+    let mut generic_args = Vec::new();
+    loop {
+        let segment = path.segment()?;
+
+        if segment.has_colon_colon() {
+            kind = PathKind::Abs;
+        }
+
+        match segment.kind()? {
+            ast::PathSegmentKind::Name(name_ref) => {
+                // FIXME: this should just return name
+                match hygiene.name_ref_to_name(name_ref) {
+                    Either::Left(name) => {
+                        let args = segment
+                            .type_arg_list()
+                            .and_then(lower_generic_args)
+                            .or_else(|| {
+                                lower_generic_args_from_fn_path(
+                                    segment.param_list(),
+                                    segment.ret_type(),
+                                )
+                            })
+                            .map(Arc::new);
+                        segments.push(name);
+                        generic_args.push(args)
+                    }
+                    Either::Right(crate_id) => {
+                        kind = PathKind::DollarCrate(crate_id);
+                        break;
+                    }
+                }
+            }
+            ast::PathSegmentKind::Type { type_ref, trait_ref } => {
+                assert!(path.qualifier().is_none()); // this can only occur at the first segment
+
+                let self_type = TypeRef::from_ast(type_ref?);
+
+                match trait_ref {
+                    // <T>::foo
+                    None => {
+                        type_anchor = Some(Box::new(self_type));
+                        kind = PathKind::Plain;
+                    }
+                    // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
+                    Some(trait_ref) => {
+                        let path = Path::from_src(trait_ref.path()?, hygiene)?;
+                        kind = path.mod_path.kind;
+
+                        let mut prefix_segments = path.mod_path.segments;
+                        prefix_segments.reverse();
+                        segments.extend(prefix_segments);
+
+                        let mut prefix_args = path.generic_args;
+                        prefix_args.reverse();
+                        generic_args.extend(prefix_args);
+
+                        // Insert the type reference (T in the above example) as Self parameter for the trait
+                        let last_segment = generic_args.last_mut()?;
+                        if last_segment.is_none() {
+                            *last_segment = Some(Arc::new(GenericArgs::empty()));
+                        };
+                        let args = last_segment.as_mut().unwrap();
+                        let mut args_inner = Arc::make_mut(args);
+                        args_inner.has_self_type = true;
+                        args_inner.args.insert(0, GenericArg::Type(self_type));
+                    }
+                }
+            }
+            ast::PathSegmentKind::CrateKw => {
+                kind = PathKind::Crate;
+                break;
+            }
+            ast::PathSegmentKind::SelfKw => {
+                kind = PathKind::Super(0);
+                break;
+            }
+            ast::PathSegmentKind::SuperKw => {
+                kind = PathKind::Super(1);
+                break;
+            }
+        }
+        path = match qualifier(&path) {
+            Some(it) => it,
+            None => break,
+        };
+    }
+    segments.reverse();
+    generic_args.reverse();
+    let mod_path = ModPath { kind, segments };
+    return Some(Path { type_anchor, mod_path, generic_args });
+
+    fn qualifier(path: &ast::Path) -> Option<ast::Path> {
+        if let Some(q) = path.qualifier() {
+            return Some(q);
+        }
+        // FIXME: this bottom up traversal is not too precise.
+        // Should we handle do a top-down analysis, recording results?
+        let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
+        let use_tree = use_tree_list.parent_use_tree();
+        use_tree.path()
+    }
+}
+
+pub(super) fn lower_generic_args(node: ast::TypeArgList) -> Option<GenericArgs> {
+    let mut args = Vec::new();
+    for type_arg in node.type_args() {
+        let type_ref = TypeRef::from_ast_opt(type_arg.type_ref());
+        args.push(GenericArg::Type(type_ref));
+    }
+    // lifetimes ignored for now
+    let mut bindings = Vec::new();
+    for assoc_type_arg in node.assoc_type_args() {
+        if let Some(name_ref) = assoc_type_arg.name_ref() {
+            let name = name_ref.as_name();
+            let type_ref = TypeRef::from_ast_opt(assoc_type_arg.type_ref());
+            bindings.push((name, type_ref));
+        }
+    }
+    if args.is_empty() && bindings.is_empty() {
+        None
+    } else {
+        Some(GenericArgs { args, has_self_type: false, bindings })
+    }
+}
+
+/// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
+/// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
+fn lower_generic_args_from_fn_path(
+    params: Option<ast::ParamList>,
+    ret_type: Option<ast::RetType>,
+) -> Option<GenericArgs> {
+    let mut args = Vec::new();
+    let mut bindings = Vec::new();
+    if let Some(params) = params {
+        let mut param_types = Vec::new();
+        for param in params.params() {
+            let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
+            param_types.push(type_ref);
+        }
+        let arg = GenericArg::Type(TypeRef::Tuple(param_types));
+        args.push(arg);
+    }
+    if let Some(ret_type) = ret_type {
+        let type_ref = TypeRef::from_ast_opt(ret_type.type_ref());
+        bindings.push((name![Output], type_ref))
+    }
+    if args.is_empty() && bindings.is_empty() {
+        None
+    } else {
+        Some(GenericArgs { args, has_self_type: false, bindings })
+    }
+}
diff --git a/crates/ra_hir_def/src/path/lower/lower_use.rs b/crates/ra_hir_def/src/path/lower/lower_use.rs
new file mode 100644
index 000000000..3218eaf0a
--- /dev/null
+++ b/crates/ra_hir_def/src/path/lower/lower_use.rs
@@ -0,0 +1,118 @@
+//! Lowers a single complex use like `use foo::{bar, baz};` into a list of paths like
+//! `foo::bar`, `foo::baz`;
+
+use std::iter;
+
+use either::Either;
+use hir_expand::{
+    hygiene::Hygiene,
+    name::{AsName, Name},
+};
+use ra_syntax::ast::{self, NameOwner};
+use test_utils::tested_by;
+
+use crate::path::{ModPath, PathKind};
+
+pub(crate) fn lower_use_tree(
+    prefix: Option<ModPath>,
+    tree: ast::UseTree,
+    hygiene: &Hygiene,
+    cb: &mut dyn FnMut(ModPath, &ast::UseTree, bool, Option<Name>),
+) {
+    if let Some(use_tree_list) = tree.use_tree_list() {
+        let prefix = match tree.path() {
+            // E.g. use something::{{{inner}}};
+            None => prefix,
+            // E.g. `use something::{inner}` (prefix is `None`, path is `something`)
+            // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
+            Some(path) => match convert_path(prefix, path, hygiene) {
+                Some(it) => Some(it),
+                None => return, // FIXME: report errors somewhere
+            },
+        };
+        for child_tree in use_tree_list.use_trees() {
+            lower_use_tree(prefix.clone(), child_tree, hygiene, cb);
+        }
+    } else {
+        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
+        let is_glob = tree.has_star();
+        if let Some(ast_path) = tree.path() {
+            // Handle self in a path.
+            // E.g. `use something::{self, <...>}`
+            if ast_path.qualifier().is_none() {
+                if let Some(segment) = ast_path.segment() {
+                    if segment.kind() == Some(ast::PathSegmentKind::SelfKw) {
+                        if let Some(prefix) = prefix {
+                            cb(prefix, &tree, false, alias);
+                            return;
+                        }
+                    }
+                }
+            }
+            if let Some(path) = convert_path(prefix, ast_path, hygiene) {
+                cb(path, &tree, is_glob, alias)
+            }
+        // FIXME: report errors somewhere
+        // We get here if we do
+        } else if is_glob {
+            tested_by!(glob_enum_group);
+            if let Some(prefix) = prefix {
+                cb(prefix, &tree, is_glob, None)
+            }
+        }
+    }
+}
+
+fn convert_path(prefix: Option<ModPath>, path: ast::Path, hygiene: &Hygiene) -> Option<ModPath> {
+    let prefix = if let Some(qual) = path.qualifier() {
+        Some(convert_path(prefix, qual, hygiene)?)
+    } else {
+        prefix
+    };
+
+    let segment = path.segment()?;
+    let res = match segment.kind()? {
+        ast::PathSegmentKind::Name(name_ref) => {
+            match hygiene.name_ref_to_name(name_ref) {
+                Either::Left(name) => {
+                    // no type args in use
+                    let mut res = prefix.unwrap_or_else(|| ModPath {
+                        kind: PathKind::Plain,
+                        segments: Vec::with_capacity(1),
+                    });
+                    res.segments.push(name);
+                    res
+                }
+                Either::Right(crate_id) => {
+                    return Some(ModPath::from_simple_segments(
+                        PathKind::DollarCrate(crate_id),
+                        iter::empty(),
+                    ))
+                }
+            }
+        }
+        ast::PathSegmentKind::CrateKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            ModPath::from_simple_segments(PathKind::Crate, iter::empty())
+        }
+        ast::PathSegmentKind::SelfKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            ModPath::from_simple_segments(PathKind::Super(0), iter::empty())
+        }
+        ast::PathSegmentKind::SuperKw => {
+            if prefix.is_some() {
+                return None;
+            }
+            ModPath::from_simple_segments(PathKind::Super(1), iter::empty())
+        }
+        ast::PathSegmentKind::Type { .. } => {
+            // not allowed in imports
+            return None;
+        }
+    };
+    Some(res)
+}
diff --git a/crates/ra_hir_def/src/per_ns.rs b/crates/ra_hir_def/src/per_ns.rs
index 00e866bf9..3a5105028 100644
--- a/crates/ra_hir_def/src/per_ns.rs
+++ b/crates/ra_hir_def/src/per_ns.rs
@@ -11,8 +11,6 @@ use crate::ModuleDefId;
 pub struct PerNs {
     pub types: Option<ModuleDefId>,
     pub values: Option<ModuleDefId>,
-    /// Since macros has different type, many methods simply ignore it.
-    /// We can only use special method like `get_macros` to access it.
     pub macros: Option<MacroDefId>,
 }
 
diff --git a/crates/ra_hir_def/src/resolver.rs b/crates/ra_hir_def/src/resolver.rs
index 0847f6dcf..cf3c33d78 100644
--- a/crates/ra_hir_def/src/resolver.rs
+++ b/crates/ra_hir_def/src/resolver.rs
@@ -2,7 +2,7 @@
 use std::sync::Arc;
 
 use hir_expand::{
-    name::{self, Name},
+    name::{name, Name},
     MacroDefId,
 };
 use ra_db::CrateId;
@@ -10,20 +10,23 @@ use rustc_hash::FxHashSet;
 
 use crate::{
     body::scope::{ExprScopes, ScopeId},
+    body::Body,
     builtin_type::BuiltinType,
     db::DefDatabase,
     expr::{ExprId, PatId},
     generics::GenericParams,
+    item_scope::BuiltinShadowMode,
     nameres::CrateDefMap,
-    path::{Path, PathKind},
+    path::{ModPath, PathKind},
     per_ns::PerNs,
-    AdtId, AstItemDef, ConstId, ContainerId, DefWithBodyId, EnumId, EnumVariantId, FunctionId,
-    GenericDefId, HasModule, ImplId, LocalModuleId, Lookup, ModuleDefId, ModuleId, StaticId,
-    StructId, TraitId, TypeAliasId,
+    AdtId, AssocContainerId, ConstId, ContainerId, DefWithBodyId, EnumId, EnumVariantId,
+    FunctionId, GenericDefId, HasModule, ImplId, LocalModuleId, Lookup, ModuleDefId, ModuleId,
+    StaticId, StructId, TraitId, TypeAliasId, TypeParamId, VariantId,
 };
 
 #[derive(Debug, Clone, Default)]
 pub struct Resolver {
+    // FIXME: all usages generally call `.rev`, so maybe reverse once in consturciton?
     scopes: Vec<Scope>,
 }
 
@@ -53,12 +56,14 @@ enum Scope {
     AdtScope(AdtId),
     /// Local bindings
     ExprScope(ExprScope),
+    /// Temporary hack to support local items.
+    LocalItemsScope(Arc<Body>),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum TypeNs {
     SelfType(ImplId),
-    GenericParam(u32),
+    GenericParam(TypeParamId),
     AdtId(AdtId),
     AdtSelfType(AdtId),
     // Yup, enum variants are added to the types ns, but any usage of variant as
@@ -90,8 +95,8 @@ pub enum ValueNs {
 
 impl Resolver {
     /// Resolve known trait from std, like `std::futures::Future`
-    pub fn resolve_known_trait(&self, db: &impl DefDatabase, path: &Path) -> Option<TraitId> {
-        let res = self.resolve_module_path(db, path).take_types()?;
+    pub fn resolve_known_trait(&self, db: &impl DefDatabase, path: &ModPath) -> Option<TraitId> {
+        let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
         match res {
             ModuleDefId::TraitId(it) => Some(it),
             _ => None,
@@ -99,8 +104,8 @@ impl Resolver {
     }
 
     /// Resolve known struct from std, like `std::boxed::Box`
-    pub fn resolve_known_struct(&self, db: &impl DefDatabase, path: &Path) -> Option<StructId> {
-        let res = self.resolve_module_path(db, path).take_types()?;
+    pub fn resolve_known_struct(&self, db: &impl DefDatabase, path: &ModPath) -> Option<StructId> {
+        let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
         match res {
             ModuleDefId::AdtId(AdtId::StructId(it)) => Some(it),
             _ => None,
@@ -108,87 +113,116 @@ impl Resolver {
     }
 
     /// Resolve known enum from std, like `std::result::Result`
-    pub fn resolve_known_enum(&self, db: &impl DefDatabase, path: &Path) -> Option<EnumId> {
-        let res = self.resolve_module_path(db, path).take_types()?;
+    pub fn resolve_known_enum(&self, db: &impl DefDatabase, path: &ModPath) -> Option<EnumId> {
+        let res = self.resolve_module_path(db, path, BuiltinShadowMode::Other).take_types()?;
         match res {
             ModuleDefId::AdtId(AdtId::EnumId(it)) => Some(it),
             _ => None,
         }
     }
 
-    /// pub only for source-binder
-    pub fn resolve_module_path(&self, db: &impl DefDatabase, path: &Path) -> PerNs {
+    fn resolve_module_path(
+        &self,
+        db: &impl DefDatabase,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
+    ) -> PerNs {
         let (item_map, module) = match self.module() {
             Some(it) => it,
             None => return PerNs::none(),
         };
-        let (module_res, segment_index) = item_map.resolve_path(db, module, path);
+        let (module_res, segment_index) = item_map.resolve_path(db, module, &path, shadow);
         if segment_index.is_some() {
             return PerNs::none();
         }
         module_res
     }
 
+    pub fn resolve_module_path_in_items(&self, db: &impl DefDatabase, path: &ModPath) -> PerNs {
+        self.resolve_module_path(db, path, BuiltinShadowMode::Module)
+    }
+
     pub fn resolve_path_in_type_ns(
         &self,
         db: &impl DefDatabase,
-        path: &Path,
+        path: &ModPath,
     ) -> Option<(TypeNs, Option<usize>)> {
-        if path.is_type_relative() {
-            return None;
-        }
-        let first_name = &path.segments.first()?.name;
+        let first_name = path.segments.first()?;
         let skip_to_mod = path.kind != PathKind::Plain;
         for scope in self.scopes.iter().rev() {
             match scope {
                 Scope::ExprScope(_) => continue,
-                Scope::GenericParams { .. } | Scope::ImplBlockScope(_) if skip_to_mod => continue,
+                Scope::GenericParams { .. }
+                | Scope::ImplBlockScope(_)
+                | Scope::LocalItemsScope(_)
+                    if skip_to_mod =>
+                {
+                    continue
+                }
 
-                Scope::GenericParams { params, .. } => {
-                    if let Some(param) = params.find_by_name(first_name) {
+                Scope::GenericParams { params, def } => {
+                    if let Some(local_id) = params.find_by_name(first_name) {
                         let idx = if path.segments.len() == 1 { None } else { Some(1) };
-                        return Some((TypeNs::GenericParam(param.idx), idx));
+                        return Some((
+                            TypeNs::GenericParam(TypeParamId { local_id, parent: *def }),
+                            idx,
+                        ));
                     }
                 }
                 Scope::ImplBlockScope(impl_) => {
-                    if first_name == &name::SELF_TYPE {
+                    if first_name == &name![Self] {
                         let idx = if path.segments.len() == 1 { None } else { Some(1) };
                         return Some((TypeNs::SelfType(*impl_), idx));
                     }
                 }
                 Scope::AdtScope(adt) => {
-                    if first_name == &name::SELF_TYPE {
+                    if first_name == &name![Self] {
                         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()? {
-                        ModuleDefId::AdtId(it) => TypeNs::AdtId(it),
-                        ModuleDefId::EnumVariantId(it) => TypeNs::EnumVariantId(it),
-
-                        ModuleDefId::TypeAliasId(it) => TypeNs::TypeAliasId(it),
-                        ModuleDefId::BuiltinType(it) => TypeNs::BuiltinType(it),
-
-                        ModuleDefId::TraitId(it) => TypeNs::TraitId(it),
-
-                        ModuleDefId::FunctionId(_)
-                        | ModuleDefId::ConstId(_)
-                        | ModuleDefId::StaticId(_)
-                        | ModuleDefId::ModuleId(_) => return None,
-                    };
+                    let (module_def, idx) = m.crate_def_map.resolve_path(
+                        db,
+                        m.module_id,
+                        &path,
+                        BuiltinShadowMode::Other,
+                    );
+                    let res = to_type_ns(module_def)?;
                     return Some((res, idx));
                 }
+                Scope::LocalItemsScope(body) => {
+                    let def = body.item_scope.get(first_name, BuiltinShadowMode::Other);
+                    if let Some(res) = to_type_ns(def) {
+                        return Some((res, None));
+                    }
+                }
             }
         }
-        None
+        return None;
+        fn to_type_ns(per_ns: PerNs) -> Option<TypeNs> {
+            let res = match per_ns.take_types()? {
+                ModuleDefId::AdtId(it) => TypeNs::AdtId(it),
+                ModuleDefId::EnumVariantId(it) => TypeNs::EnumVariantId(it),
+
+                ModuleDefId::TypeAliasId(it) => TypeNs::TypeAliasId(it),
+                ModuleDefId::BuiltinType(it) => TypeNs::BuiltinType(it),
+
+                ModuleDefId::TraitId(it) => TypeNs::TraitId(it),
+
+                ModuleDefId::FunctionId(_)
+                | ModuleDefId::ConstId(_)
+                | ModuleDefId::StaticId(_)
+                | ModuleDefId::ModuleId(_) => return None,
+            };
+            Some(res)
+        }
     }
 
     pub fn resolve_path_in_type_ns_fully(
         &self,
         db: &impl DefDatabase,
-        path: &Path,
+        path: &ModPath,
     ) -> Option<TypeNs> {
         let (res, unresolved) = self.resolve_path_in_type_ns(db, path)?;
         if unresolved.is_some() {
@@ -197,17 +231,14 @@ impl Resolver {
         Some(res)
     }
 
-    pub fn resolve_path_in_value_ns<'p>(
+    pub fn resolve_path_in_value_ns(
         &self,
         db: &impl DefDatabase,
-        path: &'p Path,
+        path: &ModPath,
     ) -> Option<ResolveValueResult> {
-        if path.is_type_relative() {
-            return None;
-        }
         let n_segments = path.segments.len();
-        let tmp = name::SELF_PARAM;
-        let first_name = if path.is_self() { &tmp } else { &path.segments.first()?.name };
+        let tmp = name![self];
+        let first_name = if path.is_self() { &tmp } else { &path.segments.first()? };
         let skip_to_mod = path.kind != PathKind::Plain && !path.is_self();
         for scope in self.scopes.iter().rev() {
             match scope {
@@ -215,6 +246,7 @@ impl Resolver {
                 | Scope::ExprScope(_)
                 | Scope::GenericParams { .. }
                 | Scope::ImplBlockScope(_)
+                | Scope::LocalItemsScope(_)
                     if skip_to_mod =>
                 {
                     continue
@@ -233,22 +265,22 @@ impl Resolver {
                 }
                 Scope::ExprScope(_) => continue,
 
-                Scope::GenericParams { params, .. } if n_segments > 1 => {
-                    if let Some(param) = params.find_by_name(first_name) {
-                        let ty = TypeNs::GenericParam(param.idx);
+                Scope::GenericParams { params, def } if n_segments > 1 => {
+                    if let Some(local_id) = params.find_by_name(first_name) {
+                        let ty = TypeNs::GenericParam(TypeParamId { local_id, parent: *def });
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
                 Scope::GenericParams { .. } => continue,
 
                 Scope::ImplBlockScope(impl_) if n_segments > 1 => {
-                    if first_name == &name::SELF_TYPE {
+                    if first_name == &name![Self] {
                         let ty = TypeNs::SelfType(*impl_);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
                 Scope::AdtScope(adt) if n_segments > 1 => {
-                    if first_name == &name::SELF_TYPE {
+                    if first_name == &name![Self] {
                         let ty = TypeNs::AdtSelfType(*adt);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
@@ -256,23 +288,15 @@ impl Resolver {
                 Scope::ImplBlockScope(_) | Scope::AdtScope(_) => continue,
 
                 Scope::ModuleScope(m) => {
-                    let (module_def, idx) = m.crate_def_map.resolve_path(db, m.module_id, path);
+                    let (module_def, idx) = m.crate_def_map.resolve_path(
+                        db,
+                        m.module_id,
+                        &path,
+                        BuiltinShadowMode::Other,
+                    );
                     return match idx {
                         None => {
-                            let value = match module_def.take_values()? {
-                                ModuleDefId::FunctionId(it) => ValueNs::FunctionId(it),
-                                ModuleDefId::AdtId(AdtId::StructId(it)) => ValueNs::StructId(it),
-                                ModuleDefId::EnumVariantId(it) => ValueNs::EnumVariantId(it),
-                                ModuleDefId::ConstId(it) => ValueNs::ConstId(it),
-                                ModuleDefId::StaticId(it) => ValueNs::StaticId(it),
-
-                                ModuleDefId::AdtId(AdtId::EnumId(_))
-                                | ModuleDefId::AdtId(AdtId::UnionId(_))
-                                | ModuleDefId::TraitId(_)
-                                | ModuleDefId::TypeAliasId(_)
-                                | ModuleDefId::BuiltinType(_)
-                                | ModuleDefId::ModuleId(_) => return None,
-                            };
+                            let value = to_value_ns(module_def)?;
                             Some(ResolveValueResult::ValueNs(value))
                         }
                         Some(idx) => {
@@ -292,15 +316,39 @@ impl Resolver {
                         }
                     };
                 }
+                Scope::LocalItemsScope(body) => {
+                    let def = body.item_scope.get(first_name, BuiltinShadowMode::Other);
+                    if let Some(res) = to_value_ns(def) {
+                        return Some(ResolveValueResult::ValueNs(res));
+                    }
+                }
             }
         }
-        None
+        return None;
+
+        fn to_value_ns(per_ns: PerNs) -> Option<ValueNs> {
+            let res = match per_ns.take_values()? {
+                ModuleDefId::FunctionId(it) => ValueNs::FunctionId(it),
+                ModuleDefId::AdtId(AdtId::StructId(it)) => ValueNs::StructId(it),
+                ModuleDefId::EnumVariantId(it) => ValueNs::EnumVariantId(it),
+                ModuleDefId::ConstId(it) => ValueNs::ConstId(it),
+                ModuleDefId::StaticId(it) => ValueNs::StaticId(it),
+
+                ModuleDefId::AdtId(AdtId::EnumId(_))
+                | ModuleDefId::AdtId(AdtId::UnionId(_))
+                | ModuleDefId::TraitId(_)
+                | ModuleDefId::TypeAliasId(_)
+                | ModuleDefId::BuiltinType(_)
+                | ModuleDefId::ModuleId(_) => return None,
+            };
+            Some(res)
+        }
     }
 
     pub fn resolve_path_in_value_ns_fully(
         &self,
         db: &impl DefDatabase,
-        path: &Path,
+        path: &ModPath,
     ) -> Option<ValueNs> {
         match self.resolve_path_in_value_ns(db, path)? {
             ResolveValueResult::ValueNs(it) => Some(it),
@@ -308,9 +356,13 @@ impl Resolver {
         }
     }
 
-    pub fn resolve_path_as_macro(&self, db: &impl DefDatabase, path: &Path) -> Option<MacroDefId> {
+    pub fn resolve_path_as_macro(
+        &self,
+        db: &impl DefDatabase,
+        path: &ModPath,
+    ) -> Option<MacroDefId> {
         let (item_map, module) = self.module()?;
-        item_map.resolve_path(db, module, path).0.take_macros()
+        item_map.resolve_path(db, module, &path, BuiltinShadowMode::Other).0.take_macros()
     }
 
     pub fn process_all_names(&self, db: &impl DefDatabase, f: &mut dyn FnMut(Name, ScopeDef)) {
@@ -350,6 +402,7 @@ impl Resolver {
     ) -> impl Iterator<Item = &'a crate::generics::WherePredicate> + 'a {
         self.scopes
             .iter()
+            .rev()
             .filter_map(|scope| match scope {
                 Scope::GenericParams { params, .. } => Some(params),
                 _ => None,
@@ -358,14 +411,14 @@ impl Resolver {
     }
 
     pub fn generic_def(&self) -> Option<GenericDefId> {
-        self.scopes.iter().find_map(|scope| match scope {
+        self.scopes.iter().rev().find_map(|scope| match scope {
             Scope::GenericParams { def, .. } => Some(*def),
             _ => None,
         })
     }
 
     pub fn body_owner(&self) -> Option<DefWithBodyId> {
-        self.scopes.iter().find_map(|scope| match scope {
+        self.scopes.iter().rev().find_map(|scope| match scope {
             Scope::ExprScope(it) => Some(it.owner),
             _ => None,
         })
@@ -376,7 +429,7 @@ pub enum ScopeDef {
     PerNs(PerNs),
     ImplSelfType(ImplId),
     AdtSelfType(AdtId),
-    GenericParam(u32),
+    GenericParam(TypeParamId),
     Local(PatId),
 }
 
@@ -391,8 +444,8 @@ impl Scope {
                 //         def: m.module.into(),
                 //     }),
                 // );
-                m.crate_def_map[m.module_id].scope.entries().for_each(|(name, res)| {
-                    f(name.clone(), ScopeDef::PerNs(res.def));
+                m.crate_def_map[m.module_id].scope.entries().for_each(|(name, def)| {
+                    f(name.clone(), ScopeDef::PerNs(def));
                 });
                 m.crate_def_map[m.module_id].scope.legacy_macros().for_each(|(name, macro_)| {
                     f(name.clone(), ScopeDef::PerNs(PerNs::macros(macro_)));
@@ -402,21 +455,29 @@ impl Scope {
                 });
                 if let Some(prelude) = m.crate_def_map.prelude {
                     let prelude_def_map = db.crate_def_map(prelude.krate);
-                    prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, res)| {
-                        f(name.clone(), ScopeDef::PerNs(res.def));
+                    prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, def)| {
+                        f(name.clone(), ScopeDef::PerNs(def));
                     });
                 }
             }
-            Scope::GenericParams { params, .. } => {
-                for param in params.params.iter() {
-                    f(param.name.clone(), ScopeDef::GenericParam(param.idx))
+            Scope::LocalItemsScope(body) => {
+                body.item_scope.entries_without_primitives().for_each(|(name, def)| {
+                    f(name.clone(), ScopeDef::PerNs(def));
+                })
+            }
+            Scope::GenericParams { params, def } => {
+                for (local_id, param) in params.types.iter() {
+                    f(
+                        param.name.clone(),
+                        ScopeDef::GenericParam(TypeParamId { local_id, parent: *def }),
+                    )
                 }
             }
             Scope::ImplBlockScope(i) => {
-                f(name::SELF_TYPE, ScopeDef::ImplSelfType((*i).into()));
+                f(name![Self], ScopeDef::ImplSelfType((*i).into()));
             }
             Scope::AdtScope(i) => {
-                f(name::SELF_TYPE, ScopeDef::AdtSelfType((*i).into()));
+                f(name![Self], ScopeDef::AdtSelfType((*i).into()));
             }
             Scope::ExprScope(scope) => {
                 scope.expr_scopes.entries(scope.scope_id).iter().for_each(|e| {
@@ -439,6 +500,7 @@ pub fn resolver_for_scope(
     scope_id: Option<ScopeId>,
 ) -> Resolver {
     let mut r = owner.resolver(db);
+    r = r.push_local_items_scope(db.body(owner));
     let scopes = db.expr_scopes(owner);
     let scope_chain = scopes.scope_chain(scope_id).collect::<Vec<_>>();
     for scope in scope_chain.into_iter().rev() {
@@ -455,7 +517,7 @@ impl Resolver {
 
     fn push_generic_params_scope(self, db: &impl DefDatabase, def: GenericDefId) -> Resolver {
         let params = db.generic_params(def);
-        if params.params.is_empty() {
+        if params.types.is_empty() {
             self
         } else {
             self.push_scope(Scope::GenericParams { def, params })
@@ -474,6 +536,10 @@ impl Resolver {
         self.push_scope(Scope::ModuleScope(ModuleItemMap { crate_def_map, module_id }))
     }
 
+    fn push_local_items_scope(self, body: Arc<Body>) -> Resolver {
+        self.push_scope(Scope::LocalItemsScope(body))
+    }
+
     fn push_expr_scope(
         self,
         owner: DefWithBodyId,
@@ -498,7 +564,7 @@ impl HasResolver for ModuleId {
 
 impl HasResolver for TraitId {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        self.module(db).resolver(db).push_generic_params_scope(db, self.into())
+        self.lookup(db).container.resolver(db).push_generic_params_scope(db, self.into())
     }
 }
 
@@ -518,16 +584,6 @@ impl HasResolver for FunctionId {
     }
 }
 
-impl HasResolver for DefWithBodyId {
-    fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        match self {
-            DefWithBodyId::ConstId(c) => c.resolver(db),
-            DefWithBodyId::FunctionId(f) => f.resolver(db),
-            DefWithBodyId::StaticId(s) => s.resolver(db),
-        }
-    }
-}
-
 impl HasResolver for ConstId {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
         self.lookup(db).container.resolver(db)
@@ -546,12 +602,41 @@ impl HasResolver for TypeAliasId {
     }
 }
 
+impl HasResolver for ImplId {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        self.lookup(db)
+            .container
+            .resolver(db)
+            .push_generic_params_scope(db, self.into())
+            .push_impl_block_scope(self)
+    }
+}
+
+impl HasResolver for DefWithBodyId {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        match self {
+            DefWithBodyId::ConstId(c) => c.resolver(db),
+            DefWithBodyId::FunctionId(f) => f.resolver(db),
+            DefWithBodyId::StaticId(s) => s.resolver(db),
+        }
+    }
+}
+
 impl HasResolver for ContainerId {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
         match self {
-            ContainerId::TraitId(it) => it.resolver(db),
-            ContainerId::ImplId(it) => it.resolver(db),
             ContainerId::ModuleId(it) => it.resolver(db),
+            ContainerId::DefWithBodyId(it) => it.resolver(db),
+        }
+    }
+}
+
+impl HasResolver for AssocContainerId {
+    fn resolver(self, db: &impl DefDatabase) -> Resolver {
+        match self {
+            AssocContainerId::ContainerId(it) => it.resolver(db),
+            AssocContainerId::TraitId(it) => it.resolver(db),
+            AssocContainerId::ImplId(it) => it.resolver(db),
         }
     }
 }
@@ -570,11 +655,12 @@ impl HasResolver for GenericDefId {
     }
 }
 
-impl HasResolver for ImplId {
+impl HasResolver for VariantId {
     fn resolver(self, db: &impl DefDatabase) -> Resolver {
-        self.module(db)
-            .resolver(db)
-            .push_generic_params_scope(db, self.into())
-            .push_impl_block_scope(self)
+        match self {
+            VariantId::EnumVariantId(it) => it.parent.resolver(db),
+            VariantId::StructId(it) => it.resolver(db),
+            VariantId::UnionId(it) => it.resolver(db),
+        }
     }
 }
diff --git a/crates/ra_hir_def/src/src.rs b/crates/ra_hir_def/src/src.rs
new file mode 100644
index 000000000..499375b80
--- /dev/null
+++ b/crates/ra_hir_def/src/src.rs
@@ -0,0 +1,36 @@
+//! Utilities for mapping between hir IDs and the surface syntax.
+
+use hir_expand::InFile;
+use ra_arena::map::ArenaMap;
+use ra_syntax::AstNode;
+
+use crate::{db::DefDatabase, AssocItemLoc, ItemLoc};
+
+pub trait HasSource {
+    type Value;
+    fn source(&self, db: &impl DefDatabase) -> InFile<Self::Value>;
+}
+
+impl<N: AstNode> HasSource for AssocItemLoc<N> {
+    type Value = N;
+
+    fn source(&self, db: &impl DefDatabase) -> InFile<N> {
+        let node = self.ast_id.to_node(db);
+        InFile::new(self.ast_id.file_id, node)
+    }
+}
+
+impl<N: AstNode> HasSource for ItemLoc<N> {
+    type Value = N;
+
+    fn source(&self, db: &impl DefDatabase) -> InFile<N> {
+        let node = self.ast_id.to_node(db);
+        InFile::new(self.ast_id.file_id, node)
+    }
+}
+
+pub trait HasChildSource {
+    type ChildId;
+    type Value;
+    fn child_source(&self, db: &impl DefDatabase) -> InFile<ArenaMap<Self::ChildId, Self::Value>>;
+}
diff --git a/crates/ra_hir_def/src/trace.rs b/crates/ra_hir_def/src/trace.rs
index 2bcd707bc..9769e88df 100644
--- a/crates/ra_hir_def/src/trace.rs
+++ b/crates/ra_hir_def/src/trace.rs
@@ -18,10 +18,6 @@ pub(crate) struct Trace<ID: ArenaId, T, V> {
 }
 
 impl<ID: ra_arena::ArenaId + Copy, T, V> Trace<ID, T, V> {
-    pub(crate) fn new() -> Trace<ID, T, V> {
-        Trace { arena: Some(Arena::default()), map: Some(ArenaMap::default()), len: 0 }
-    }
-
     pub(crate) fn new_for_arena() -> Trace<ID, T, V> {
         Trace { arena: Some(Arena::default()), map: None, len: 0 }
     }
@@ -52,8 +48,4 @@ impl<ID: ra_arena::ArenaId + Copy, T, V> Trace<ID, T, V> {
     pub(crate) fn into_map(mut self) -> ArenaMap<ID, V> {
         self.map.take().unwrap()
     }
-
-    pub(crate) fn into_arena_and_map(mut self) -> (Arena<ID, T>, ArenaMap<ID, V>) {
-        (self.arena.take().unwrap(), self.map.take().unwrap())
-    }
 }
diff --git a/crates/ra_hir_expand/Cargo.toml b/crates/ra_hir_expand/Cargo.toml
index c60152a79..3ae4376dc 100644
--- a/crates/ra_hir_expand/Cargo.toml
+++ b/crates/ra_hir_expand/Cargo.toml
@@ -9,6 +9,7 @@ doctest = false
 
 [dependencies]
 log = "0.4.5"
+either = "1.5"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_expand/src/ast_id_map.rs b/crates/ra_hir_expand/src/ast_id_map.rs
index cb464c3ff..a764bdf24 100644
--- a/crates/ra_hir_expand/src/ast_id_map.rs
+++ b/crates/ra_hir_expand/src/ast_id_map.rs
@@ -39,6 +39,16 @@ impl<N: AstNode> Hash for FileAstId<N> {
     }
 }
 
+impl<N: AstNode> FileAstId<N> {
+    // Can't make this a From implementation because of coherence
+    pub fn upcast<M: AstNode>(self) -> FileAstId<M>
+    where
+        M: From<N>,
+    {
+        FileAstId { raw: self.raw, _ty: PhantomData }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 struct ErasedFileAstId(RawId);
 impl_arena_id!(ErasedFileAstId);
@@ -53,7 +63,7 @@ impl AstIdMap {
     pub(crate) fn from_source(node: &SyntaxNode) -> AstIdMap {
         assert!(node.parent().is_none());
         let mut res = AstIdMap { arena: Arena::default() };
-        // By walking the tree in bread-first order we make sure that parents
+        // By walking the tree in breadth-first order we make sure that parents
         // get lower ids then children. That is, adding a new child does not
         // change parent's id. This means that, say, adding a new function to a
         // trait does not change ids of top-level items, which helps caching.
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
new file mode 100644
index 000000000..62c60e336
--- /dev/null
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -0,0 +1,321 @@
+//! Builtin derives.
+
+use log::debug;
+
+use ra_parser::FragmentKind;
+use ra_syntax::{
+    ast::{self, AstNode, ModuleItemOwner, NameOwner, TypeParamsOwner},
+    match_ast,
+};
+
+use crate::db::AstDatabase;
+use crate::{name, quote, MacroCallId, MacroDefId, MacroDefKind};
+
+macro_rules! register_builtin {
+    ( $($trait:ident => $expand:ident),* ) => {
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+        pub enum BuiltinDeriveExpander {
+            $($trait),*
+        }
+
+        impl BuiltinDeriveExpander {
+            pub fn expand(
+                &self,
+                db: &dyn AstDatabase,
+                id: MacroCallId,
+                tt: &tt::Subtree,
+            ) -> Result<tt::Subtree, mbe::ExpandError> {
+                let expander = match *self {
+                    $( BuiltinDeriveExpander::$trait => $expand, )*
+                };
+                expander(db, id, tt)
+            }
+        }
+
+        pub fn find_builtin_derive(ident: &name::Name) -> Option<MacroDefId> {
+            let kind = match ident {
+                $( id if id == &name::name![$trait] => BuiltinDeriveExpander::$trait, )*
+                 _ => return None,
+            };
+
+            Some(MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(kind) })
+        }
+    };
+}
+
+register_builtin! {
+    Copy => copy_expand,
+    Clone => clone_expand,
+    Default => default_expand,
+    Debug => debug_expand,
+    Hash => hash_expand,
+    Ord => ord_expand,
+    PartialOrd => partial_ord_expand,
+    Eq => eq_expand,
+    PartialEq => partial_eq_expand
+}
+
+struct BasicAdtInfo {
+    name: tt::Ident,
+    type_params: usize,
+}
+
+fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, mbe::ExpandError> {
+    let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, FragmentKind::Items)?; // FragmentKind::Items doesn't parse attrs?
+    let macro_items = ast::MacroItems::cast(parsed.syntax_node()).ok_or_else(|| {
+        debug!("derive node didn't parse");
+        mbe::ExpandError::UnexpectedToken
+    })?;
+    let item = macro_items.items().next().ok_or_else(|| {
+        debug!("no module item parsed");
+        mbe::ExpandError::NoMatchingRule
+    })?;
+    let node = item.syntax();
+    let (name, params) = match_ast! {
+        match node {
+            ast::StructDef(it) => { (it.name(), it.type_param_list()) },
+            ast::EnumDef(it) => { (it.name(), it.type_param_list()) },
+            ast::UnionDef(it) => { (it.name(), it.type_param_list()) },
+            _ => {
+                debug!("unexpected node is {:?}", node);
+                return Err(mbe::ExpandError::ConversionError)
+            },
+        }
+    };
+    let name = name.ok_or_else(|| {
+        debug!("parsed item has no name");
+        mbe::ExpandError::NoMatchingRule
+    })?;
+    let name_token_id = token_map.token_by_range(name.syntax().text_range()).ok_or_else(|| {
+        debug!("name token not found");
+        mbe::ExpandError::ConversionError
+    })?;
+    let name_token = tt::Ident { id: name_token_id, text: name.text().clone() };
+    let type_params = params.map_or(0, |type_param_list| type_param_list.type_params().count());
+    Ok(BasicAdtInfo { name: name_token, type_params })
+}
+
+fn make_type_args(n: usize, bound: Vec<tt::TokenTree>) -> Vec<tt::TokenTree> {
+    let mut result = Vec::<tt::TokenTree>::new();
+    result.push(
+        tt::Leaf::Punct(tt::Punct {
+            char: '<',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        })
+        .into(),
+    );
+    for i in 0..n {
+        if i > 0 {
+            result.push(
+                tt::Leaf::Punct(tt::Punct {
+                    char: ',',
+                    spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
+                })
+                .into(),
+            );
+        }
+        result.push(
+            tt::Leaf::Ident(tt::Ident {
+                id: tt::TokenId::unspecified(),
+                text: format!("T{}", i).into(),
+            })
+            .into(),
+        );
+        result.extend(bound.iter().cloned());
+    }
+    result.push(
+        tt::Leaf::Punct(tt::Punct {
+            char: '>',
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        })
+        .into(),
+    );
+    result
+}
+
+fn expand_simple_derive(
+    tt: &tt::Subtree,
+    trait_path: tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    let info = parse_adt(tt)?;
+    let name = info.name;
+    let trait_path_clone = trait_path.token_trees.clone();
+    let bound = (quote! { : ##trait_path_clone }).token_trees;
+    let type_params = make_type_args(info.type_params, bound);
+    let type_args = make_type_args(info.type_params, Vec::new());
+    let trait_path = trait_path.token_trees;
+    let expanded = quote! {
+        impl ##type_params ##trait_path for #name ##type_args {}
+    };
+    Ok(expanded)
+}
+
+fn copy_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::marker::Copy })
+}
+
+fn clone_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::clone::Clone })
+}
+
+fn default_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::default::Default })
+}
+
+fn debug_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::fmt::Debug })
+}
+
+fn hash_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::hash::Hash })
+}
+
+fn eq_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::Eq })
+}
+
+fn partial_eq_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::PartialEq })
+}
+
+fn ord_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::Ord })
+}
+
+fn partial_ord_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    expand_simple_derive(tt, quote! { std::cmp::PartialOrd })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{test_db::TestDB, AstId, MacroCallKind, MacroCallLoc};
+    use ra_db::{fixture::WithFixture, SourceDatabase};
+
+    fn expand_builtin_derive(s: &str, expander: BuiltinDeriveExpander) -> String {
+        let (db, file_id) = TestDB::with_single_file(&s);
+        let parsed = db.parse(file_id);
+        let items: Vec<_> =
+            parsed.syntax_node().descendants().filter_map(|it| ast::ModuleItem::cast(it)).collect();
+
+        let ast_id_map = db.ast_id_map(file_id.into());
+
+        // the first one should be a macro_rules
+        let def =
+            MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(expander) };
+
+        let loc = MacroCallLoc {
+            def,
+            kind: MacroCallKind::Attr(AstId::new(file_id.into(), ast_id_map.ast_id(&items[0]))),
+        };
+
+        let id = db.intern_macro(loc);
+        let parsed = db.parse_or_expand(id.as_file()).unwrap();
+
+        // FIXME text() for syntax nodes parsed from token tree looks weird
+        // because there's no whitespace, see below
+        parsed.text().to_string()
+    }
+
+    #[test]
+    fn test_copy_expand_simple() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        assert_eq!(expanded, "impl <>std::marker::CopyforFoo <>{}");
+    }
+
+    #[test]
+    fn test_copy_expand_with_type_params() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo<A, B>;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+        );
+    }
+
+    #[test]
+    fn test_copy_expand_with_lifetimes() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Copy)]
+        struct Foo<A, B, 'a, 'b>;
+"#,
+            BuiltinDeriveExpander::Copy,
+        );
+
+        // We currently just ignore lifetimes
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::marker::Copy,T1:std::marker::Copy>std::marker::CopyforFoo<T0,T1>{}"
+        );
+    }
+
+    #[test]
+    fn test_clone_expand() {
+        let expanded = expand_builtin_derive(
+            r#"
+        #[derive(Clone)]
+        struct Foo<A, B>;
+"#,
+            BuiltinDeriveExpander::Clone,
+        );
+
+        assert_eq!(
+            expanded,
+            "impl<T0:std::clone::Clone,T1:std::clone::Clone>std::clone::CloneforFoo<T0,T1>{}"
+        );
+    }
+}
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index d370dfb34..2c119269c 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -2,8 +2,7 @@
 use crate::db::AstDatabase;
 use crate::{
     ast::{self, AstNode},
-    name, AstId, CrateId, HirFileId, MacroCallId, MacroDefId, MacroDefKind, MacroFileKind,
-    TextUnit,
+    name, AstId, CrateId, HirFileId, MacroCallId, MacroDefId, MacroDefKind, TextUnit,
 };
 
 use crate::quote;
@@ -27,6 +26,13 @@ macro_rules! register_builtin {
                 };
                 expander(db, id, tt)
             }
+
+            fn by_name(ident: &name::Name) -> Option<BuiltinFnLikeExpander> {
+                match ident {
+                    $( id if id == &name::name![$name] => Some(BuiltinFnLikeExpander::$kind), )*
+                    _ => return None,
+                }
+            }
         }
 
         pub fn find_builtin_macro(
@@ -34,22 +40,25 @@ macro_rules! register_builtin {
             krate: CrateId,
             ast_id: AstId<ast::MacroCall>,
         ) -> Option<MacroDefId> {
-            let kind = match ident {
-                 $( id if id == &name::$name => BuiltinFnLikeExpander::$kind, )*
-                 _ => return None,
-            };
+            let kind = BuiltinFnLikeExpander::by_name(ident)?;
 
-            Some(MacroDefId { krate, ast_id, kind: MacroDefKind::BuiltIn(kind) })
+            Some(MacroDefId { krate: Some(krate), ast_id: Some(ast_id), kind: MacroDefKind::BuiltIn(kind) })
         }
     };
 }
 
 register_builtin! {
-    (COLUMN_MACRO, Column) => column_expand,
-    (COMPILE_ERROR_MACRO, CompileError) => compile_error_expand,
-    (FILE_MACRO, File) => file_expand,
-    (LINE_MACRO, Line) => line_expand,
-    (STRINGIFY_MACRO, Stringify) => stringify_expand
+    (column, Column) => column_expand,
+    (compile_error, CompileError) => compile_error_expand,
+    (file, File) => file_expand,
+    (line, Line) => line_expand,
+    (stringify, Stringify) => stringify_expand,
+    (format_args, FormatArgs) => format_args_expand,
+    (env, Env) => env_expand,
+    (option_env, OptionEnv) => option_env_expand,
+    // format_args_nl only differs in that it adds a newline in the end,
+    // so we use the same stub expansion for now
+    (format_args_nl, FormatArgsNl) => format_args_expand
 }
 
 fn to_line_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
@@ -82,12 +91,11 @@ fn line_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
 
-    let arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-    let arg_start = arg.syntax().text_range().start();
+    let arg = loc.kind.arg(db).ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
+    let arg_start = arg.text_range().start();
 
-    let file = id.as_file(MacroFileKind::Expr);
+    let file = id.as_file();
     let line_num = to_line_number(db, file, arg_start);
 
     let expanded = quote! {
@@ -103,11 +111,10 @@ fn stringify_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
 
     let macro_content = {
-        let arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-        let macro_args = arg.syntax().clone();
+        let arg = loc.kind.arg(db).ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
+        let macro_args = arg;
         let text = macro_args.text();
         let without_parens = TextUnit::of_char('(')..text.len() - TextUnit::of_char(')');
         text.slice(without_parens).to_string()
@@ -120,6 +127,28 @@ fn stringify_expand(
     Ok(expanded)
 }
 
+fn env_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    _tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // dummy implementation for type-checking purposes
+    let expanded = quote! { "" };
+
+    Ok(expanded)
+}
+
+fn option_env_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    _tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // dummy implementation for type-checking purposes
+    let expanded = quote! { std::option::Option::None::<&str> };
+
+    Ok(expanded)
+}
+
 fn to_col_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize {
     // FIXME: Use expansion info
     let file_id = file.original_file(db);
@@ -137,7 +166,7 @@ fn to_col_number(db: &dyn AstDatabase, file: HirFileId, pos: TextUnit) -> usize
         if c == '\n' {
             break;
         }
-        col_num = col_num + 1;
+        col_num += 1;
     }
     col_num
 }
@@ -148,12 +177,15 @@ fn column_expand(
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
+    let macro_call = match loc.kind {
+        crate::MacroCallKind::FnLike(ast_id) => ast_id.to_node(db),
+        _ => panic!("column macro called as attr"),
+    };
 
     let _arg = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
     let col_start = macro_call.syntax().text_range().start();
 
-    let file = id.as_file(MacroFileKind::Expr);
+    let file = id.as_file();
     let col_num = to_col_number(db, file, col_start);
 
     let expanded = quote! {
@@ -164,15 +196,10 @@ fn column_expand(
 }
 
 fn file_expand(
-    db: &dyn AstDatabase,
-    id: MacroCallId,
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
     _tt: &tt::Subtree,
 ) -> Result<tt::Subtree, mbe::ExpandError> {
-    let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
-
-    let _ = macro_call.token_tree().ok_or_else(|| mbe::ExpandError::UnexpectedToken)?;
-
     // FIXME: RA purposefully lacks knowledge of absolute file names
     // so just return "".
     let file_name = "";
@@ -204,13 +231,56 @@ fn compile_error_expand(
     Err(mbe::ExpandError::BindingError("Must be a string".into()))
 }
 
+fn format_args_expand(
+    _db: &dyn AstDatabase,
+    _id: MacroCallId,
+    tt: &tt::Subtree,
+) -> Result<tt::Subtree, mbe::ExpandError> {
+    // We expand `format_args!("", a1, a2)` to
+    // ```
+    // std::fmt::Arguments::new_v1(&[], &[
+    //   std::fmt::ArgumentV1::new(&arg1,std::fmt::Display::fmt),
+    //   std::fmt::ArgumentV1::new(&arg2,std::fmt::Display::fmt),
+    // ])
+    // ```,
+    // which is still not really correct, but close enough for now
+    let mut args = Vec::new();
+    let mut current = Vec::new();
+    for tt in tt.token_trees.iter().cloned() {
+        match tt {
+            tt::TokenTree::Leaf(tt::Leaf::Punct(p)) if p.char == ',' => {
+                args.push(current);
+                current = Vec::new();
+            }
+            _ => {
+                current.push(tt);
+            }
+        }
+    }
+    if !current.is_empty() {
+        args.push(current);
+    }
+    if args.is_empty() {
+        return Err(mbe::ExpandError::NoMatchingRule);
+    }
+    let _format_string = args.remove(0);
+    let arg_tts = args.into_iter().flat_map(|arg| {
+        quote! { std::fmt::ArgumentV1::new(&(##arg), std::fmt::Display::fmt), }
+    }.token_trees).collect::<Vec<_>>();
+    let expanded = quote! {
+        std::fmt::Arguments::new_v1(&[], &[##arg_tts])
+    };
+    Ok(expanded)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{test_db::TestDB, MacroCallLoc};
+    use crate::{name::AsName, test_db::TestDB, MacroCallKind, MacroCallLoc};
     use ra_db::{fixture::WithFixture, SourceDatabase};
+    use ra_syntax::ast::NameOwner;
 
-    fn expand_builtin_macro(s: &str, expander: BuiltinFnLikeExpander) -> String {
+    fn expand_builtin_macro(s: &str) -> String {
         let (db, file_id) = TestDB::with_single_file(&s);
         let parsed = db.parse(file_id);
         let macro_calls: Vec<_> =
@@ -218,20 +288,26 @@ mod tests {
 
         let ast_id_map = db.ast_id_map(file_id.into());
 
+        let expander =
+            BuiltinFnLikeExpander::by_name(&macro_calls[0].name().unwrap().as_name()).unwrap();
+
         // the first one should be a macro_rules
         let def = MacroDefId {
-            krate: CrateId(0),
-            ast_id: AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0])),
+            krate: Some(CrateId(0)),
+            ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
             kind: MacroDefKind::BuiltIn(expander),
         };
 
         let loc = MacroCallLoc {
             def,
-            ast_id: AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[1])),
+            kind: MacroCallKind::FnLike(AstId::new(
+                file_id.into(),
+                ast_id_map.ast_id(&macro_calls[1]),
+            )),
         };
 
         let id = db.intern_macro(loc);
-        let parsed = db.parse_or_expand(id.as_file(MacroFileKind::Expr)).unwrap();
+        let parsed = db.parse_or_expand(id.as_file()).unwrap();
 
         parsed.text().to_string()
     }
@@ -240,25 +316,23 @@ mod tests {
     fn test_column_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! column {() => {}}
-        column!()
-"#,
-            BuiltinFnLikeExpander::Column,
+            #[rustc_builtin_macro]
+            macro_rules! column {() => {}}
+            column!()
+            "#,
         );
 
-        assert_eq!(expanded, "9");
+        assert_eq!(expanded, "13");
     }
 
     #[test]
     fn test_line_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! line {() => {}}
-        line!()
-"#,
-            BuiltinFnLikeExpander::Line,
+            #[rustc_builtin_macro]
+            macro_rules! line {() => {}}
+            line!()
+            "#,
         );
 
         assert_eq!(expanded, "4");
@@ -268,25 +342,49 @@ mod tests {
     fn test_stringify_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! stringify {() => {}}
-        stringify!(a b c)
-"#,
-            BuiltinFnLikeExpander::Stringify,
+            #[rustc_builtin_macro]
+            macro_rules! stringify {() => {}}
+            stringify!(a b c)
+            "#,
         );
 
         assert_eq!(expanded, "\"a b c\"");
     }
 
     #[test]
+    fn test_env_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! env {() => {}}
+            env!("TEST_ENV_VAR")
+            "#,
+        );
+
+        assert_eq!(expanded, "\"\"");
+    }
+
+    #[test]
+    fn test_option_env_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! option_env {() => {}}
+            option_env!("TEST_ENV_VAR")
+            "#,
+        );
+
+        assert_eq!(expanded, "std::option::Option::None:: <&str>");
+    }
+
+    #[test]
     fn test_file_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! file {() => {}}
-        file!()
-"#,
-            BuiltinFnLikeExpander::File,
+            #[rustc_builtin_macro]
+            macro_rules! file {() => {}}
+            file!()
+            "#,
         );
 
         assert_eq!(expanded, "\"\"");
@@ -296,16 +394,34 @@ mod tests {
     fn test_compile_error_expand() {
         let expanded = expand_builtin_macro(
             r#"
-        #[rustc_builtin_macro]
-        macro_rules! compile_error {
-            ($msg:expr) => ({ /* compiler built-in */ });
-            ($msg:expr,) => ({ /* compiler built-in */ })
-        }
-        compile_error!("error!");
-"#,
-            BuiltinFnLikeExpander::CompileError,
+            #[rustc_builtin_macro]
+            macro_rules! compile_error {
+                ($msg:expr) => ({ /* compiler built-in */ });
+                ($msg:expr,) => ({ /* compiler built-in */ })
+            }
+            compile_error!("error!");
+            "#,
         );
 
         assert_eq!(expanded, r#"loop{"error!"}"#);
     }
+
+    #[test]
+    fn test_format_args_expand() {
+        let expanded = expand_builtin_macro(
+            r#"
+            #[rustc_builtin_macro]
+            macro_rules! format_args {
+                ($fmt:expr) => ({ /* compiler built-in */ });
+                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            format_args!("{} {:?}", arg1(a, b, c), arg2);
+            "#,
+        );
+
+        assert_eq!(
+            expanded,
+            r#"std::fmt::Arguments::new_v1(&[] ,&[std::fmt::ArgumentV1::new(&(arg1(a,b,c)),std::fmt::Display::fmt),std::fmt::ArgumentV1::new(&(arg2),std::fmt::Display::fmt),])"#
+        );
+    }
 }
diff --git a/crates/ra_hir_expand/src/db.rs b/crates/ra_hir_expand/src/db.rs
index 8e46fa177..2e12e126f 100644
--- a/crates/ra_hir_expand/src/db.rs
+++ b/crates/ra_hir_expand/src/db.rs
@@ -6,17 +6,18 @@ use mbe::MacroRules;
 use ra_db::{salsa, SourceDatabase};
 use ra_parser::FragmentKind;
 use ra_prof::profile;
-use ra_syntax::{AstNode, Parse, SyntaxNode};
+use ra_syntax::{AstNode, Parse, SyntaxKind::*, SyntaxNode};
 
 use crate::{
-    ast_id_map::AstIdMap, BuiltinFnLikeExpander, HirFileId, HirFileIdRepr, MacroCallId,
-    MacroCallLoc, MacroDefId, MacroDefKind, MacroFile, MacroFileKind,
+    ast_id_map::AstIdMap, BuiltinDeriveExpander, BuiltinFnLikeExpander, HirFileId, HirFileIdRepr,
+    MacroCallId, MacroCallLoc, MacroDefId, MacroDefKind, MacroFile,
 };
 
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub enum TokenExpander {
     MacroRules(mbe::MacroRules),
     Builtin(BuiltinFnLikeExpander),
+    BuiltinDerive(BuiltinDeriveExpander),
 }
 
 impl TokenExpander {
@@ -29,6 +30,7 @@ impl TokenExpander {
         match self {
             TokenExpander::MacroRules(it) => it.expand(tt),
             TokenExpander::Builtin(it) => it.expand(db, id, tt),
+            TokenExpander::BuiltinDerive(it) => it.expand(db, id, tt),
         }
     }
 
@@ -36,13 +38,15 @@ impl TokenExpander {
         match self {
             TokenExpander::MacroRules(it) => it.map_id_down(id),
             TokenExpander::Builtin(..) => id,
+            TokenExpander::BuiltinDerive(..) => id,
         }
     }
 
     pub fn map_id_up(&self, id: tt::TokenId) -> (tt::TokenId, mbe::Origin) {
         match self {
             TokenExpander::MacroRules(it) => it.map_id_up(id),
-            TokenExpander::Builtin(..) => (id, mbe::Origin::Def),
+            TokenExpander::Builtin(..) => (id, mbe::Origin::Call),
+            TokenExpander::BuiltinDerive(..) => (id, mbe::Origin::Call),
         }
     }
 }
@@ -76,7 +80,7 @@ pub(crate) fn macro_def(
 ) -> Option<Arc<(TokenExpander, mbe::TokenMap)>> {
     match id.kind {
         MacroDefKind::Declarative => {
-            let macro_call = id.ast_id.to_node(db);
+            let macro_call = id.ast_id?.to_node(db);
             let arg = macro_call.token_tree()?;
             let (tt, tmap) = mbe::ast_to_token_tree(&arg).or_else(|| {
                 log::warn!("fail on macro_def to token tree: {:#?}", arg);
@@ -89,7 +93,10 @@ pub(crate) fn macro_def(
             Some(Arc::new((TokenExpander::MacroRules(rules), tmap)))
         }
         MacroDefKind::BuiltIn(expander) => {
-            Some(Arc::new((TokenExpander::Builtin(expander.clone()), mbe::TokenMap::default())))
+            Some(Arc::new((TokenExpander::Builtin(expander), mbe::TokenMap::default())))
+        }
+        MacroDefKind::BuiltInDerive(expander) => {
+            Some(Arc::new((TokenExpander::BuiltinDerive(expander), mbe::TokenMap::default())))
         }
     }
 }
@@ -99,9 +106,8 @@ pub(crate) fn macro_arg(
     id: MacroCallId,
 ) -> Option<Arc<(tt::Subtree, mbe::TokenMap)>> {
     let loc = db.lookup_intern_macro(id);
-    let macro_call = loc.ast_id.to_node(db);
-    let arg = macro_call.token_tree()?;
-    let (tt, tmap) = mbe::ast_to_token_tree(&arg)?;
+    let arg = loc.kind.arg(db)?;
+    let (tt, tmap) = mbe::syntax_node_to_token_tree(&arg)?;
     Some(Arc::new((tt, tmap)))
 }
 
@@ -148,11 +154,43 @@ pub(crate) fn parse_macro(
         })
         .ok()?;
 
-    let fragment_kind = match macro_file.macro_file_kind {
-        MacroFileKind::Items => FragmentKind::Items,
-        MacroFileKind::Expr => FragmentKind::Expr,
-        MacroFileKind::Statements => FragmentKind::Statements,
-    };
+    let fragment_kind = to_fragment_kind(db, macro_call_id);
+
     let (parse, rev_token_map) = mbe::token_tree_to_syntax_node(&tt, fragment_kind).ok()?;
     Some((parse, Arc::new(rev_token_map)))
 }
+
+/// Given a `MacroCallId`, return what `FragmentKind` it belongs to.
+/// FIXME: Not completed
+fn to_fragment_kind(db: &dyn AstDatabase, macro_call_id: MacroCallId) -> FragmentKind {
+    let syn = db.lookup_intern_macro(macro_call_id).kind.node(db).value;
+
+    let parent = match syn.parent() {
+        Some(it) => it,
+        None => {
+            // FIXME:
+            // If it is root, which means the parent HirFile
+            // MacroKindFile must be non-items
+            // return expr now.
+            return FragmentKind::Expr;
+        }
+    };
+
+    match parent.kind() {
+        MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
+        LET_STMT => {
+            // FIXME: Handle Pattern
+            FragmentKind::Expr
+        }
+        // FIXME: Expand to statements in appropriate positions; HIR lowering needs to handle that
+        EXPR_STMT | BLOCK => FragmentKind::Expr,
+        ARG_LIST => FragmentKind::Expr,
+        TRY_EXPR => FragmentKind::Expr,
+        TUPLE_EXPR => FragmentKind::Expr,
+        ITEM_LIST => FragmentKind::Items,
+        _ => {
+            // Unknown , Just guess it is `Items`
+            FragmentKind::Items
+        }
+    }
+}
diff --git a/crates/ra_hir_expand/src/diagnostics.rs b/crates/ra_hir_expand/src/diagnostics.rs
index 3d37e9335..108c1e38c 100644
--- a/crates/ra_hir_expand/src/diagnostics.rs
+++ b/crates/ra_hir_expand/src/diagnostics.rs
@@ -18,11 +18,11 @@ use std::{any::Any, fmt};
 
 use ra_syntax::{SyntaxNode, SyntaxNodePtr, TextRange};
 
-use crate::{db::AstDatabase, Source};
+use crate::{db::AstDatabase, InFile};
 
 pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
     fn message(&self) -> String;
-    fn source(&self) -> Source<SyntaxNodePtr>;
+    fn source(&self) -> InFile<SyntaxNodePtr>;
     fn highlight_range(&self) -> TextRange {
         self.source().value.range()
     }
diff --git a/crates/ra_hir_expand/src/either.rs b/crates/ra_hir_expand/src/either.rs
deleted file mode 100644
index 83583ef8b..000000000
--- a/crates/ra_hir_expand/src/either.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-//! FIXME: write short doc here
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Either<A, B> {
-    A(A),
-    B(B),
-}
-
-impl<A, B> Either<A, B> {
-    pub fn either<R, F1, F2>(self, f1: F1, f2: F2) -> R
-    where
-        F1: FnOnce(A) -> R,
-        F2: FnOnce(B) -> R,
-    {
-        match self {
-            Either::A(a) => f1(a),
-            Either::B(b) => f2(b),
-        }
-    }
-    pub fn map<U, V, F1, F2>(self, f1: F1, f2: F2) -> Either<U, V>
-    where
-        F1: FnOnce(A) -> U,
-        F2: FnOnce(B) -> V,
-    {
-        match self {
-            Either::A(a) => Either::A(f1(a)),
-            Either::B(b) => Either::B(f2(b)),
-        }
-    }
-    pub fn map_a<U, F>(self, f: F) -> Either<U, B>
-    where
-        F: FnOnce(A) -> U,
-    {
-        self.map(f, |it| it)
-    }
-    pub fn a(self) -> Option<A> {
-        match self {
-            Either::A(it) => Some(it),
-            Either::B(_) => None,
-        }
-    }
-    pub fn b(self) -> Option<B> {
-        match self {
-            Either::A(_) => None,
-            Either::B(it) => Some(it),
-        }
-    }
-    pub fn as_ref(&self) -> Either<&A, &B> {
-        match self {
-            Either::A(it) => Either::A(it),
-            Either::B(it) => Either::B(it),
-        }
-    }
-}
diff --git a/crates/ra_hir_expand/src/hygiene.rs b/crates/ra_hir_expand/src/hygiene.rs
index 379562a2c..2e8a533f7 100644
--- a/crates/ra_hir_expand/src/hygiene.rs
+++ b/crates/ra_hir_expand/src/hygiene.rs
@@ -2,12 +2,12 @@
 //!
 //! Specifically, `ast` + `Hygiene` allows you to create a `Name`. Note that, at
 //! this moment, this is horribly incomplete and handles only `$crate`.
+use either::Either;
 use ra_db::CrateId;
 use ra_syntax::ast;
 
 use crate::{
     db::AstDatabase,
-    either::Either,
     name::{AsName, Name},
     HirFileId, HirFileIdRepr, MacroDefKind,
 };
@@ -25,8 +25,9 @@ impl Hygiene {
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc = db.lookup_intern_macro(macro_file.macro_call_id);
                 match loc.def.kind {
-                    MacroDefKind::Declarative => Some(loc.def.krate),
+                    MacroDefKind::Declarative => loc.def.krate,
                     MacroDefKind::BuiltIn(_) => None,
+                    MacroDefKind::BuiltInDerive(_) => None,
                 }
             }
         };
@@ -41,9 +42,9 @@ impl Hygiene {
     pub fn name_ref_to_name(&self, name_ref: ast::NameRef) -> Either<Name, CrateId> {
         if let Some(def_crate) = self.def_crate {
             if name_ref.text() == "$crate" {
-                return Either::B(def_crate);
+                return Either::Right(def_crate);
             }
         }
-        Either::A(name_ref.as_name())
+        Either::Left(name_ref.as_name())
     }
 }
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index b6a739cda..2fa5d5140 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -6,14 +6,14 @@
 
 pub mod db;
 pub mod ast_id_map;
-pub mod either;
 pub mod name;
 pub mod hygiene;
 pub mod diagnostics;
+pub mod builtin_derive;
 pub mod builtin_macro;
 pub mod quote;
 
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
 use std::sync::Arc;
 
 use ra_db::{salsa, CrateId, FileId};
@@ -24,6 +24,7 @@ use ra_syntax::{
 };
 
 use crate::ast_id_map::FileAstId;
+use crate::builtin_derive::BuiltinDeriveExpander;
 use crate::builtin_macro::BuiltinFnLikeExpander;
 
 #[cfg(test)]
@@ -70,7 +71,18 @@ impl HirFileId {
             HirFileIdRepr::FileId(file_id) => file_id,
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc = db.lookup_intern_macro(macro_file.macro_call_id);
-                loc.ast_id.file_id().original_file(db)
+                loc.kind.file_id().original_file(db)
+            }
+        }
+    }
+
+    /// If this is a macro call, returns the syntax node of the call.
+    pub fn call_node(self, db: &dyn db::AstDatabase) -> Option<InFile<SyntaxNode>> {
+        match self.0 {
+            HirFileIdRepr::FileId(_) => None,
+            HirFileIdRepr::MacroFile(macro_file) => {
+                let loc = db.lookup_intern_macro(macro_file.macro_call_id);
+                Some(loc.kind.node(db))
             }
         }
     }
@@ -82,17 +94,17 @@ impl HirFileId {
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc: MacroCallLoc = db.lookup_intern_macro(macro_file.macro_call_id);
 
-                let arg_tt = loc.ast_id.to_node(db).token_tree()?;
-                let def_tt = loc.def.ast_id.to_node(db).token_tree()?;
+                let arg_tt = loc.kind.arg(db)?;
+                let def_tt = loc.def.ast_id?.to_node(db).token_tree()?;
 
                 let macro_def = db.macro_def(loc.def)?;
                 let (parse, exp_map) = db.parse_macro(macro_file)?;
                 let macro_arg = db.macro_arg(macro_file.macro_call_id)?;
 
                 Some(ExpansionInfo {
-                    expanded: Source::new(self, parse.syntax_node()),
-                    arg: Source::new(loc.ast_id.file_id, arg_tt),
-                    def: Source::new(loc.ast_id.file_id, def_tt),
+                    expanded: InFile::new(self, parse.syntax_node()),
+                    arg: InFile::new(loc.kind.file_id(), arg_tt),
+                    def: InFile::new(loc.def.ast_id?.file_id, def_tt),
                     macro_arg,
                     macro_def,
                     exp_map,
@@ -105,14 +117,6 @@ impl HirFileId {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct MacroFile {
     macro_call_id: MacroCallId,
-    macro_file_kind: MacroFileKind,
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum MacroFileKind {
-    Items,
-    Expr,
-    Statements,
 }
 
 /// `MacroCallId` identifies a particular macro invocation, like
@@ -130,18 +134,20 @@ impl salsa::InternKey for MacroCallId {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct MacroDefId {
-    pub krate: CrateId,
-    pub ast_id: AstId<ast::MacroCall>,
+    // FIXME: krate and ast_id are currently optional because we don't have a
+    // definition location for built-in derives. There is one, though: the
+    // standard library defines them. The problem is that it uses the new
+    // `macro` syntax for this, which we don't support yet. As soon as we do
+    // (which will probably require touching this code), we can instead use
+    // that (and also remove the hacks for resolving built-in derives).
+    pub krate: Option<CrateId>,
+    pub ast_id: Option<AstId<ast::MacroCall>>,
     pub kind: MacroDefKind,
 }
 
 impl MacroDefId {
-    pub fn as_call_id(
-        self,
-        db: &dyn db::AstDatabase,
-        ast_id: AstId<ast::MacroCall>,
-    ) -> MacroCallId {
-        db.intern_macro(MacroCallLoc { def: self, ast_id })
+    pub fn as_call_id(self, db: &dyn db::AstDatabase, kind: MacroCallKind) -> MacroCallId {
+        db.intern_macro(MacroCallLoc { def: self, kind })
     }
 }
 
@@ -149,64 +155,103 @@ impl MacroDefId {
 pub enum MacroDefKind {
     Declarative,
     BuiltIn(BuiltinFnLikeExpander),
+    // FIXME: maybe just Builtin and rename BuiltinFnLikeExpander to BuiltinExpander
+    BuiltInDerive(BuiltinDeriveExpander),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub(crate) def: MacroDefId,
-    pub(crate) ast_id: AstId<ast::MacroCall>,
+    pub(crate) kind: MacroCallKind,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum MacroCallKind {
+    FnLike(AstId<ast::MacroCall>),
+    Attr(AstId<ast::ModuleItem>),
+}
+
+impl MacroCallKind {
+    pub fn file_id(&self) -> HirFileId {
+        match self {
+            MacroCallKind::FnLike(ast_id) => ast_id.file_id,
+            MacroCallKind::Attr(ast_id) => ast_id.file_id,
+        }
+    }
+
+    pub fn node(&self, db: &dyn db::AstDatabase) -> InFile<SyntaxNode> {
+        match self {
+            MacroCallKind::FnLike(ast_id) => ast_id.with_value(ast_id.to_node(db).syntax().clone()),
+            MacroCallKind::Attr(ast_id) => ast_id.with_value(ast_id.to_node(db).syntax().clone()),
+        }
+    }
+
+    pub fn arg(&self, db: &dyn db::AstDatabase) -> Option<SyntaxNode> {
+        match self {
+            MacroCallKind::FnLike(ast_id) => {
+                Some(ast_id.to_node(db).token_tree()?.syntax().clone())
+            }
+            MacroCallKind::Attr(ast_id) => Some(ast_id.to_node(db).syntax().clone()),
+        }
+    }
 }
 
 impl MacroCallId {
-    pub fn as_file(self, kind: MacroFileKind) -> HirFileId {
-        let macro_file = MacroFile { macro_call_id: self, macro_file_kind: kind };
-        macro_file.into()
+    pub fn as_file(self) -> HirFileId {
+        MacroFile { macro_call_id: self }.into()
     }
 }
 
 /// ExpansionInfo mainly describes how to map text range between src and expanded macro
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ExpansionInfo {
-    expanded: Source<SyntaxNode>,
-    arg: Source<ast::TokenTree>,
-    def: Source<ast::TokenTree>,
+    expanded: InFile<SyntaxNode>,
+    arg: InFile<SyntaxNode>,
+    def: InFile<ast::TokenTree>,
 
     macro_def: Arc<(db::TokenExpander, mbe::TokenMap)>,
     macro_arg: Arc<(tt::Subtree, mbe::TokenMap)>,
     exp_map: Arc<mbe::TokenMap>,
 }
 
+pub use mbe::Origin;
+
 impl ExpansionInfo {
-    pub fn map_token_down(&self, token: Source<&SyntaxToken>) -> Option<Source<SyntaxToken>> {
+    pub fn call_node(&self) -> Option<InFile<SyntaxNode>> {
+        Some(self.arg.with_value(self.arg.value.parent()?))
+    }
+
+    pub fn map_token_down(&self, token: InFile<&SyntaxToken>) -> Option<InFile<SyntaxToken>> {
         assert_eq!(token.file_id, self.arg.file_id);
-        let range =
-            token.value.text_range().checked_sub(self.arg.value.syntax().text_range().start())?;
+        let range = token.value.text_range().checked_sub(self.arg.value.text_range().start())?;
         let token_id = self.macro_arg.1.token_by_range(range)?;
         let token_id = self.macro_def.0.map_id_down(token_id);
 
-        let range = self.exp_map.range_by_token(token_id)?;
+        let range = self.exp_map.range_by_token(token_id)?.by_kind(token.value.kind())?;
 
         let token = algo::find_covering_element(&self.expanded.value, range).into_token()?;
 
         Some(self.expanded.with_value(token))
     }
 
-    pub fn map_token_up(&self, token: Source<&SyntaxToken>) -> Option<Source<SyntaxToken>> {
+    pub fn map_token_up(
+        &self,
+        token: InFile<&SyntaxToken>,
+    ) -> Option<(InFile<SyntaxToken>, Origin)> {
         let token_id = self.exp_map.token_by_range(token.value.text_range())?;
 
         let (token_id, origin) = self.macro_def.0.map_id_up(token_id);
         let (token_map, tt) = match origin {
-            mbe::Origin::Call => (&self.macro_arg.1, &self.arg),
-            mbe::Origin::Def => (&self.macro_def.1, &self.def),
+            mbe::Origin::Call => (&self.macro_arg.1, self.arg.clone()),
+            mbe::Origin::Def => {
+                (&self.macro_def.1, self.def.as_ref().map(|tt| tt.syntax().clone()))
+            }
         };
 
-        let range = token_map.range_by_token(token_id)?;
-        let token = algo::find_covering_element(
-            tt.value.syntax(),
-            range + tt.value.syntax().text_range().start(),
-        )
-        .into_token()?;
-        Some(tt.with_value(token))
+        let range = token_map.range_by_token(token_id)?.by_kind(token.value.kind())?;
+        let token = algo::find_covering_element(&tt.value, range + tt.value.text_range().start())
+            .into_token()?;
+        Some((tt.with_value(token), origin))
     }
 }
 
@@ -214,76 +259,66 @@ impl ExpansionInfo {
 ///
 /// It is stable across reparses, and can be used as salsa key/value.
 // FIXME: isn't this just a `Source<FileAstId<N>>` ?
-#[derive(Debug)]
-pub struct AstId<N: AstNode> {
-    file_id: HirFileId,
-    file_ast_id: FileAstId<N>,
-}
-
-impl<N: AstNode> Clone for AstId<N> {
-    fn clone(&self) -> AstId<N> {
-        *self
-    }
-}
-impl<N: AstNode> Copy for AstId<N> {}
-
-impl<N: AstNode> PartialEq for AstId<N> {
-    fn eq(&self, other: &Self) -> bool {
-        (self.file_id, self.file_ast_id) == (other.file_id, other.file_ast_id)
-    }
-}
-impl<N: AstNode> Eq for AstId<N> {}
-impl<N: AstNode> Hash for AstId<N> {
-    fn hash<H: Hasher>(&self, hasher: &mut H) {
-        (self.file_id, self.file_ast_id).hash(hasher);
-    }
-}
+pub type AstId<N> = InFile<FileAstId<N>>;
 
 impl<N: AstNode> AstId<N> {
-    pub fn new(file_id: HirFileId, file_ast_id: FileAstId<N>) -> AstId<N> {
-        AstId { file_id, file_ast_id }
-    }
-
-    pub fn file_id(&self) -> HirFileId {
-        self.file_id
-    }
-
     pub fn to_node(&self, db: &dyn db::AstDatabase) -> N {
         let root = db.parse_or_expand(self.file_id).unwrap();
-        db.ast_id_map(self.file_id).get(self.file_ast_id).to_node(&root)
+        db.ast_id_map(self.file_id).get(self.value).to_node(&root)
     }
 }
 
-/// `Source<T>` stores a value of `T` inside a particular file/syntax tree.
+/// `InFile<T>` stores a value of `T` inside a particular file/syntax tree.
 ///
 /// Typical usages are:
 ///
-/// * `Source<SyntaxNode>` -- syntax node in a file
-/// * `Source<ast::FnDef>` -- ast node in a file
-/// * `Source<TextUnit>` -- offset in a file
+/// * `InFile<SyntaxNode>` -- syntax node in a file
+/// * `InFile<ast::FnDef>` -- ast node in a file
+/// * `InFile<TextUnit>` -- offset in a file
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
-pub struct Source<T> {
+pub struct InFile<T> {
     pub file_id: HirFileId,
     pub value: T,
 }
 
-impl<T> Source<T> {
-    pub fn new(file_id: HirFileId, value: T) -> Source<T> {
-        Source { file_id, value }
+impl<T> InFile<T> {
+    pub fn new(file_id: HirFileId, value: T) -> InFile<T> {
+        InFile { file_id, value }
     }
 
     // Similarly, naming here is stupid...
-    pub fn with_value<U>(&self, value: U) -> Source<U> {
-        Source::new(self.file_id, value)
+    pub fn with_value<U>(&self, value: U) -> InFile<U> {
+        InFile::new(self.file_id, value)
     }
 
-    pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> Source<U> {
-        Source::new(self.file_id, f(self.value))
+    pub fn map<F: FnOnce(T) -> U, U>(self, f: F) -> InFile<U> {
+        InFile::new(self.file_id, f(self.value))
     }
-    pub fn as_ref(&self) -> Source<&T> {
+    pub fn as_ref(&self) -> InFile<&T> {
         self.with_value(&self.value)
     }
     pub fn file_syntax(&self, db: &impl db::AstDatabase) -> SyntaxNode {
         db.parse_or_expand(self.file_id).expect("source created from invalid file")
     }
 }
+
+impl<T: Clone> InFile<&T> {
+    pub fn cloned(&self) -> InFile<T> {
+        self.with_value(self.value.clone())
+    }
+}
+
+impl InFile<SyntaxNode> {
+    pub fn ancestors_with_macros<'a>(
+        self,
+        db: &'a impl crate::db::AstDatabase,
+    ) -> impl Iterator<Item = InFile<SyntaxNode>> + 'a {
+        std::iter::successors(Some(self), move |node| match node.value.parent() {
+            Some(parent) => Some(node.with_value(parent)),
+            None => {
+                let parent_node = node.file_id.call_node(db)?;
+                Some(parent_node)
+            }
+        })
+    }
+}
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index 7824489d7..e62693b68 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -38,8 +38,8 @@ impl Name {
     }
 
     /// Shortcut to create inline plain text name
-    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
-        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
+    const fn new_inline_ascii(text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(text.len(), text))
     }
 
     /// Resolve a name from the text of token.
@@ -83,6 +83,12 @@ impl AsName for ast::Name {
     }
 }
 
+impl AsName for tt::Ident {
+    fn as_name(&self) -> Name {
+        Name::resolve(&self.text)
+    }
+}
+
 impl AsName for ast::FieldKind {
     fn as_name(&self) -> Name {
         match self {
@@ -98,52 +104,102 @@ impl AsName for ra_db::Dependency {
     }
 }
 
-// Primitives
-pub const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
-pub const I8: Name = Name::new_inline_ascii(2, b"i8");
-pub const I16: Name = Name::new_inline_ascii(3, b"i16");
-pub const I32: Name = Name::new_inline_ascii(3, b"i32");
-pub const I64: Name = Name::new_inline_ascii(3, b"i64");
-pub const I128: Name = Name::new_inline_ascii(4, b"i128");
-pub const USIZE: Name = Name::new_inline_ascii(5, b"usize");
-pub const U8: Name = Name::new_inline_ascii(2, b"u8");
-pub const U16: Name = Name::new_inline_ascii(3, b"u16");
-pub const U32: Name = Name::new_inline_ascii(3, b"u32");
-pub const U64: Name = Name::new_inline_ascii(3, b"u64");
-pub const U128: Name = Name::new_inline_ascii(4, b"u128");
-pub const F32: Name = Name::new_inline_ascii(3, b"f32");
-pub const F64: Name = Name::new_inline_ascii(3, b"f64");
-pub const BOOL: Name = Name::new_inline_ascii(4, b"bool");
-pub const CHAR: Name = Name::new_inline_ascii(4, b"char");
-pub const STR: Name = Name::new_inline_ascii(3, b"str");
-
-// Special names
-pub const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
-pub const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
-pub const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
-
-// Components of known path (value or mod name)
-pub const STD: Name = Name::new_inline_ascii(3, b"std");
-pub const ITER: Name = Name::new_inline_ascii(4, b"iter");
-pub const OPS: Name = Name::new_inline_ascii(3, b"ops");
-pub const FUTURE: Name = Name::new_inline_ascii(6, b"future");
-pub const RESULT: Name = Name::new_inline_ascii(6, b"result");
-pub const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
-
-// Components of known path (type name)
-pub const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
-pub const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
-pub const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
-pub const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
-pub const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
-pub const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
-pub const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
-pub const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
-pub const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");
-
-// Builtin Macros
-pub const FILE_MACRO: Name = Name::new_inline_ascii(4, b"file");
-pub const COLUMN_MACRO: Name = Name::new_inline_ascii(6, b"column");
-pub const COMPILE_ERROR_MACRO: Name = Name::new_inline_ascii(13, b"compile_error");
-pub const LINE_MACRO: Name = Name::new_inline_ascii(4, b"line");
-pub const STRINGIFY_MACRO: Name = Name::new_inline_ascii(9, b"stringify");
+pub mod known {
+    macro_rules! known_names {
+        ($($ident:ident),* $(,)?) => {
+            $(
+                #[allow(bad_style)]
+                pub const $ident: super::Name =
+                    super::Name::new_inline_ascii(stringify!($ident).as_bytes());
+            )*
+        };
+    }
+
+    known_names!(
+        // Primitives
+        isize,
+        i8,
+        i16,
+        i32,
+        i64,
+        i128,
+        usize,
+        u8,
+        u16,
+        u32,
+        u64,
+        u128,
+        f32,
+        f64,
+        bool,
+        char,
+        str,
+        // Special names
+        macro_rules,
+        // Components of known path (value or mod name)
+        std,
+        iter,
+        ops,
+        future,
+        result,
+        boxed,
+        // Components of known path (type name)
+        IntoIterator,
+        Item,
+        Try,
+        Ok,
+        Future,
+        Result,
+        Output,
+        Target,
+        Box,
+        RangeFrom,
+        RangeFull,
+        RangeInclusive,
+        RangeToInclusive,
+        RangeTo,
+        Range,
+        Neg,
+        Not,
+        Index,
+        // Builtin macros
+        file,
+        column,
+        compile_error,
+        line,
+        stringify,
+        format_args,
+        format_args_nl,
+        env,
+        option_env,
+        // Builtin derives
+        Copy,
+        Clone,
+        Default,
+        Debug,
+        Hash,
+        Ord,
+        PartialOrd,
+        Eq,
+        PartialEq,
+    );
+
+    // self/Self cannot be used as an identifier
+    pub const SELF_PARAM: super::Name = super::Name::new_inline_ascii(b"self");
+    pub const SELF_TYPE: super::Name = super::Name::new_inline_ascii(b"Self");
+
+    #[macro_export]
+    macro_rules! name {
+        (self) => {
+            $crate::name::known::SELF_PARAM
+        };
+        (Self) => {
+            $crate::name::known::SELF_TYPE
+        };
+        ($ident:ident) => {
+            $crate::name::known::$ident
+        };
+    }
+}
+
+pub use crate::name;
diff --git a/crates/ra_hir_expand/src/quote.rs b/crates/ra_hir_expand/src/quote.rs
index 65a35e52f..4de219ce4 100644
--- a/crates/ra_hir_expand/src/quote.rs
+++ b/crates/ra_hir_expand/src/quote.rs
@@ -16,7 +16,10 @@ macro_rules! __quote {
         {
             let children = $crate::__quote!($($tt)*);
             let subtree = tt::Subtree {
-                delimiter: tt::Delimiter::$delim,
+                delimiter: Some(tt::Delimiter {
+                    kind: tt::DelimiterKind::$delim,
+                    id: tt::TokenId::unspecified(),
+                }),
                 token_trees: $crate::quote::IntoTt::to_tokens(children),
             };
             subtree
@@ -29,6 +32,7 @@ macro_rules! __quote {
                 tt::Leaf::Punct(tt::Punct {
                     char: $first,
                     spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
                 }).into()
             ]
         }
@@ -40,10 +44,12 @@ macro_rules! __quote {
                 tt::Leaf::Punct(tt::Punct {
                     char: $first,
                     spacing: tt::Spacing::Joint,
+                    id: tt::TokenId::unspecified(),
                 }).into(),
                 tt::Leaf::Punct(tt::Punct {
                     char: $sec,
                     spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
                 }).into()
             ]
         }
@@ -60,6 +66,15 @@ macro_rules! __quote {
         }
     };
 
+    ( ## $first:ident $($tail:tt)* ) => {
+        {
+            let mut tokens = $first.into_iter().map($crate::quote::ToTokenTree::to_token).collect::<Vec<tt::TokenTree>>();
+            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($($tail)*));
+            tokens.append(&mut tail_tokens);
+            tokens
+        }
+    };
+
     // Brace
     ( { $($tt:tt)* } ) => { $crate::__quote!(@SUBTREE Brace $($tt)*) };
     // Bracket
@@ -85,7 +100,10 @@ macro_rules! __quote {
     ( & ) => {$crate::__quote!(@PUNCT '&')};
     ( , ) => {$crate::__quote!(@PUNCT ',')};
     ( : ) => {$crate::__quote!(@PUNCT ':')};
+    ( :: ) => {$crate::__quote!(@PUNCT ':', ':')};
     ( . ) => {$crate::__quote!(@PUNCT '.')};
+    ( < ) => {$crate::__quote!(@PUNCT '<')};
+    ( > ) => {$crate::__quote!(@PUNCT '>')};
 
     ( $first:tt $($tail:tt)+ ) => {
         {
@@ -114,7 +132,7 @@ pub(crate) trait IntoTt {
 
 impl IntoTt for Vec<tt::TokenTree> {
     fn to_subtree(self) -> tt::Subtree {
-        tt::Subtree { delimiter: tt::Delimiter::None, token_trees: self }
+        tt::Subtree { delimiter: None, token_trees: self }
     }
 
     fn to_tokens(self) -> Vec<tt::TokenTree> {
@@ -169,15 +187,15 @@ macro_rules! impl_to_to_tokentrees {
 }
 
 impl_to_to_tokentrees! {
-    u32 => self { tt::Literal{text: self.to_string().into()} };
-    usize => self { tt::Literal{text: self.to_string().into()}};
-    i32 => self { tt::Literal{text: self.to_string().into()}};
+    u32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()} };
+    usize => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
+    i32 => self { tt::Literal{text: self.to_string().into(), id: tt::TokenId::unspecified()}};
     tt::Leaf => self { self };
     tt::Literal => self { self };
     tt::Ident => self { self };
     tt::Punct => self { self };
-    &str => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into()}};
-    String => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into()}}
+    &str => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}};
+    String => self { tt::Literal{text: format!("{:?}", self.escape_default().to_string()).into(), id: tt::TokenId::unspecified()}}
 }
 
 #[cfg(test)]
@@ -244,7 +262,13 @@ mod tests {
         let fields =
             fields.iter().map(|it| quote!(#it: self.#it.clone(), ).token_trees.clone()).flatten();
 
-        let list = tt::Subtree { delimiter: tt::Delimiter::Brace, token_trees: fields.collect() };
+        let list = tt::Subtree {
+            delimiter: Some(tt::Delimiter {
+                kind: tt::DelimiterKind::Brace,
+                id: tt::TokenId::unspecified(),
+            }),
+            token_trees: fields.collect(),
+        };
 
         let quoted = quote! {
             impl Clone for #struct_name {
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 429242870..60793db44 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -21,10 +21,9 @@ ra_prof = { path = "../ra_prof" }
 ra_syntax = { path = "../ra_syntax" }
 test_utils = { path = "../test_utils" }
 
-# https://github.com/rust-lang/chalk/pull/294
-chalk-solve =   { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
-chalk-rust-ir = { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
-chalk-ir =      { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
+chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
+chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
+chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
 
 lalrpop-intern = "0.15.1"
 
diff --git a/crates/ra_hir_ty/src/autoderef.rs b/crates/ra_hir_ty/src/autoderef.rs
index 9d1d4e48c..f32d5786a 100644
--- a/crates/ra_hir_ty/src/autoderef.rs
+++ b/crates/ra_hir_ty/src/autoderef.rs
@@ -6,14 +6,14 @@
 use std::iter::successors;
 
 use hir_def::lang_item::LangItemTarget;
-use hir_expand::name;
+use hir_expand::name::name;
 use log::{info, warn};
 use ra_db::CrateId;
 
-use crate::db::HirDatabase;
-
-use super::{
+use crate::{
+    db::HirDatabase,
     traits::{InEnvironment, Solution},
+    utils::generics,
     Canonical, Substs, Ty, TypeWalk,
 };
 
@@ -48,14 +48,14 @@ fn deref_by_trait(
     krate: CrateId,
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
-    let deref_trait = match db.lang_item(krate.into(), "deref".into())? {
+    let deref_trait = match db.lang_item(krate, "deref".into())? {
         LangItemTarget::TraitId(it) => it,
         _ => return None,
     };
-    let target = db.trait_data(deref_trait).associated_type_by_name(&name::TARGET_TYPE)?;
+    let target = db.trait_data(deref_trait).associated_type_by_name(&name![Target])?;
 
-    let generic_params = db.generic_params(target.into());
-    if generic_params.count_params_including_parent() != 1 {
+    let generic_params = generics(db, target.into());
+    if generic_params.len() != 1 {
         // the Target type + Deref trait should only have one generic parameter,
         // namely Deref's Self type
         return None;
@@ -78,7 +78,7 @@ fn deref_by_trait(
 
     let canonical = super::Canonical { num_vars: 1 + ty.value.num_vars, value: in_env };
 
-    let solution = db.trait_solve(krate.into(), canonical)?;
+    let solution = db.trait_solve(krate, canonical)?;
 
     match &solution {
         Solution::Unique(vars) => {
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 9ce154593..d52f65b83 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -10,8 +10,8 @@ use ra_db::{salsa, CrateId};
 
 use crate::{
     method_resolution::CrateImplBlocks,
-    traits::{AssocTyValue, Impl},
-    CallableDef, FnSig, GenericPredicate, ImplTy, InferenceResult, Substs, Ty, TyDefId, TypeCtor,
+    traits::{chalk, AssocTyValue, Impl},
+    CallableDef, FnSig, GenericPredicate, InferenceResult, Substs, TraitRef, Ty, TyDefId, TypeCtor,
     ValueTyDefId,
 };
 
@@ -22,13 +22,18 @@ pub trait HirDatabase: DefDatabase {
     fn infer(&self, def: DefWithBodyId) -> Arc<InferenceResult>;
 
     #[salsa::invoke(crate::lower::ty_query)]
+    #[salsa::cycle(crate::lower::ty_recover)]
     fn ty(&self, def: TyDefId) -> Ty;
 
     #[salsa::invoke(crate::lower::value_ty_query)]
     fn value_ty(&self, def: ValueTyDefId) -> Ty;
 
-    #[salsa::invoke(crate::lower::impl_ty_query)]
-    fn impl_ty(&self, def: ImplId) -> ImplTy;
+    #[salsa::invoke(crate::lower::impl_self_ty_query)]
+    #[salsa::cycle(crate::lower::impl_self_ty_recover)]
+    fn impl_self_ty(&self, def: ImplId) -> Ty;
+
+    #[salsa::invoke(crate::lower::impl_trait_query)]
+    fn impl_trait(&self, def: ImplId) -> Option<TraitRef>;
 
     #[salsa::invoke(crate::lower::field_types_query)]
     fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalStructFieldId, Ty>>;
@@ -37,6 +42,7 @@ pub trait HirDatabase: DefDatabase {
     fn callable_item_signature(&self, def: CallableDef) -> FnSig;
 
     #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
+    #[salsa::cycle(crate::lower::generic_predicates_for_param_recover)]
     fn generic_predicates_for_param(
         &self,
         def: GenericDefId,
@@ -71,39 +77,24 @@ pub trait HirDatabase: DefDatabase {
     #[salsa::interned]
     fn intern_assoc_ty_value(&self, assoc_ty_value: AssocTyValue) -> crate::traits::AssocTyValueId;
 
-    #[salsa::invoke(crate::traits::chalk::associated_ty_data_query)]
-    fn associated_ty_data(
-        &self,
-        id: chalk_ir::TypeId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::associated_ty_data_query)]
+    fn associated_ty_data(&self, id: chalk::AssocTypeId) -> Arc<chalk::AssociatedTyDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::trait_datum_query)]
-    fn trait_datum(
-        &self,
-        krate: CrateId,
-        trait_id: chalk_ir::TraitId,
-    ) -> Arc<chalk_rust_ir::TraitDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::trait_datum_query)]
+    fn trait_datum(&self, krate: CrateId, trait_id: chalk::TraitId) -> Arc<chalk::TraitDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::struct_datum_query)]
-    fn struct_datum(
-        &self,
-        krate: CrateId,
-        struct_id: chalk_ir::StructId,
-    ) -> Arc<chalk_rust_ir::StructDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::struct_datum_query)]
+    fn struct_datum(&self, krate: CrateId, struct_id: chalk::StructId) -> Arc<chalk::StructDatum>;
 
     #[salsa::invoke(crate::traits::chalk::impl_datum_query)]
-    fn impl_datum(
-        &self,
-        krate: CrateId,
-        impl_id: chalk_ir::ImplId,
-    ) -> Arc<chalk_rust_ir::ImplDatum<chalk_ir::family::ChalkIr>>;
+    fn impl_datum(&self, krate: CrateId, impl_id: chalk::ImplId) -> Arc<chalk::ImplDatum>;
 
     #[salsa::invoke(crate::traits::chalk::associated_ty_value_query)]
     fn associated_ty_value(
         &self,
         krate: CrateId,
-        id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyValue<chalk_ir::family::ChalkIr>>;
+        id: chalk::AssociatedTyValueId,
+    ) -> Arc<chalk::AssociatedTyValue>;
 
     #[salsa::invoke(crate::traits::trait_solve_query)]
     fn trait_solve(
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 4a13fac23..5054189cc 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -2,7 +2,7 @@
 
 use std::any::Any;
 
-use hir_expand::{db::AstDatabase, name::Name, HirFileId, Source};
+use hir_expand::{db::AstDatabase, name::Name, HirFileId, InFile};
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
 
 pub use hir_def::diagnostics::UnresolvedModule;
@@ -19,8 +19,8 @@ impl Diagnostic for NoSuchField {
         "no such field".to_string()
     }
 
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.field.into() }
     }
 
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -44,8 +44,8 @@ impl Diagnostic for MissingFields {
         }
         message
     }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field_list.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.field_list.into() }
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
@@ -72,8 +72,8 @@ impl Diagnostic for MissingOkInTailExpr {
     fn message(&self) -> String {
         "wrap return expression in Ok".to_string()
     }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.expr.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.expr.into() }
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index 9bb3ece6c..dcca1bace 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -10,6 +10,7 @@ pub struct HirFormatter<'a, 'b, DB> {
     buf: String,
     curr_size: usize,
     max_size: Option<usize>,
+    should_display_default_types: bool,
 }
 
 pub trait HirDisplay {
@@ -19,7 +20,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, None)
+        HirDisplayWrapper(db, self, None, true)
     }
 
     fn display_truncated<'a, DB>(
@@ -30,7 +31,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, max_size)
+        HirDisplayWrapper(db, self, max_size, false)
     }
 }
 
@@ -72,9 +73,13 @@ where
             false
         }
     }
+
+    pub fn should_display_default_types(&self) -> bool {
+        self.should_display_default_types
+    }
 }
 
-pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>);
+pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>, bool);
 
 impl<'a, DB, T> fmt::Display for HirDisplayWrapper<'a, DB, T>
 where
@@ -88,6 +93,7 @@ where
             buf: String::with_capacity(20),
             curr_size: 0,
             max_size: self.2,
+            should_display_default_types: self.3,
         })
     }
 }
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index 5c65f9370..f752a9f09 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -3,7 +3,7 @@
 use std::sync::Arc;
 
 use hir_def::{
-    path::{known, Path},
+    path::{path, Path},
     resolver::HasResolver,
     AdtId, FunctionId,
 };
@@ -97,7 +97,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         let (_, source_map) = db.body_with_source_map(self.func.into());
 
         if let Some(source_ptr) = source_map.expr_syntax(id) {
-            if let Some(expr) = source_ptr.value.a() {
+            if let Some(expr) = source_ptr.value.left() {
                 let root = source_ptr.file_syntax(db);
                 if let ast::Expr::RecordLit(record_lit) = expr.to_node(&root) {
                     if let Some(field_list) = record_lit.record_field_list() {
@@ -124,7 +124,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             None => return,
         };
 
-        let std_result_path = known::std_result_result();
+        let std_result_path = path![std::result::Result];
 
         let resolver = self.func.resolver(db);
         let std_result_enum = match resolver.resolve_known_enum(db, &std_result_path) {
@@ -142,7 +142,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             let (_, source_map) = db.body_with_source_map(self.func.into());
 
             if let Some(source_ptr) = source_map.expr_syntax(id) {
-                if let Some(expr) = source_ptr.value.a() {
+                if let Some(expr) = source_ptr.value.left() {
                     self.sink.push(MissingOkInTailExpr { file: source_ptr.file_id, expr });
                 }
             }
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index 1e9f4b208..e97b81473 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -18,19 +18,18 @@ use std::mem;
 use std::ops::Index;
 use std::sync::Arc;
 
-use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
 use rustc_hash::FxHashMap;
 
 use hir_def::{
     body::Body,
     data::{ConstData, FunctionData},
     expr::{BindingAnnotation, ExprId, PatId},
-    path::{known, Path},
+    path::{path, Path},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{Mutability, TypeRef},
     AdtId, AssocItemId, DefWithBodyId, FunctionId, StructFieldId, TypeAliasId, VariantId,
 };
-use hir_expand::{diagnostics::DiagnosticSink, name};
+use hir_expand::{diagnostics::DiagnosticSink, name::name};
 use ra_arena::map::ArenaMap;
 use ra_prof::profile;
 use test_utils::tested_by;
@@ -43,6 +42,8 @@ use super::{
 };
 use crate::{db::HirDatabase, infer::diagnostics::InferenceDiagnostic};
 
+pub(crate) use unify::unify;
+
 macro_rules! ty_app {
     ($ctor:pat, $param:pat) => {
         crate::Ty::Apply(crate::ApplicationTy { ctor: $ctor, parameters: $param })
@@ -191,11 +192,16 @@ struct InferenceContext<'a, D: HirDatabase> {
     owner: DefWithBodyId,
     body: Arc<Body>,
     resolver: Resolver,
-    var_unification_table: InPlaceUnificationTable<TypeVarId>,
+    table: unify::InferenceTable,
     trait_env: Arc<TraitEnvironment>,
     obligations: Vec<Obligation>,
     result: InferenceResult,
-    /// The return type of the function being inferred.
+    /// The return type of the function being inferred, or the closure if we're
+    /// currently within one.
+    ///
+    /// We might consider using a nested inference context for checking
+    /// closures, but currently this is the only field that will change there,
+    /// so it doesn't make sense.
     return_ty: Ty,
 
     /// Impls of `CoerceUnsized` used in coercion.
@@ -209,7 +215,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn new(db: &'a D, owner: DefWithBodyId, resolver: Resolver) -> Self {
         InferenceContext {
             result: InferenceResult::default(),
-            var_unification_table: InPlaceUnificationTable::new(),
+            table: unify::InferenceTable::new(),
             obligations: Vec::default(),
             return_ty: Ty::Unknown, // set in collect_fn_signature
             trait_env: TraitEnvironment::lower(db, &resolver),
@@ -224,13 +230,12 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     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());
-        let mut tv_stack = Vec::new();
         for ty in result.type_of_expr.values_mut() {
-            let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
+            let resolved = self.table.resolve_ty_completely(mem::replace(ty, Ty::Unknown));
             *ty = resolved;
         }
         for ty in result.type_of_pat.values_mut() {
-            let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
+            let resolved = self.table.resolve_ty_completely(mem::replace(ty, Ty::Unknown));
             *ty = resolved;
         }
         result
@@ -275,96 +280,38 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         self.normalize_associated_types_in(ty)
     }
 
-    fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
-        substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
-    }
-
-    fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
-        self.unify_inner(ty1, ty2, 0)
-    }
-
-    fn unify_inner(&mut self, ty1: &Ty, ty2: &Ty, depth: usize) -> bool {
-        if depth > 1000 {
-            // prevent stackoverflows
-            panic!("infinite recursion in unification");
-        }
-        if ty1 == ty2 {
-            return true;
-        }
-        // try to resolve type vars first
-        let ty1 = self.resolve_ty_shallow(ty1);
-        let ty2 = self.resolve_ty_shallow(ty2);
-        match (&*ty1, &*ty2) {
-            (Ty::Apply(a_ty1), Ty::Apply(a_ty2)) if a_ty1.ctor == a_ty2.ctor => {
-                self.unify_substs(&a_ty1.parameters, &a_ty2.parameters, depth + 1)
-            }
-            _ => self.unify_inner_trivial(&ty1, &ty2),
-        }
-    }
-
-    fn unify_inner_trivial(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
-        match (ty1, ty2) {
-            (Ty::Unknown, _) | (_, Ty::Unknown) => true,
-
-            (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
-            | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
-            | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
-            | (
-                Ty::Infer(InferTy::MaybeNeverTypeVar(tv1)),
-                Ty::Infer(InferTy::MaybeNeverTypeVar(tv2)),
-            ) => {
-                // both type vars are unknown since we tried to resolve them
-                self.var_unification_table.union(*tv1, *tv2);
-                true
-            }
-
-            // The order of MaybeNeverTypeVar matters here.
-            // Unifying MaybeNeverTypeVar and TypeVar will let the latter become MaybeNeverTypeVar.
-            // Unifying MaybeNeverTypeVar and other concrete type will let the former become it.
-            (Ty::Infer(InferTy::TypeVar(tv)), other)
-            | (other, Ty::Infer(InferTy::TypeVar(tv)))
-            | (Ty::Infer(InferTy::MaybeNeverTypeVar(tv)), other)
-            | (other, Ty::Infer(InferTy::MaybeNeverTypeVar(tv)))
-            | (Ty::Infer(InferTy::IntVar(tv)), other @ ty_app!(TypeCtor::Int(_)))
-            | (other @ ty_app!(TypeCtor::Int(_)), Ty::Infer(InferTy::IntVar(tv)))
-            | (Ty::Infer(InferTy::FloatVar(tv)), other @ ty_app!(TypeCtor::Float(_)))
-            | (other @ ty_app!(TypeCtor::Float(_)), Ty::Infer(InferTy::FloatVar(tv))) => {
-                // the type var is unknown since we tried to resolve it
-                self.var_unification_table.union_value(*tv, TypeVarValue::Known(other.clone()));
-                true
+    /// Replaces `impl Trait` in `ty` by type variables and obligations for
+    /// those variables. This is done for function arguments when calling a
+    /// function, and for return types when inside the function body, i.e. in
+    /// the cases where the `impl Trait` is 'transparent'. In other cases, `impl
+    /// Trait` is represented by `Ty::Opaque`.
+    fn insert_vars_for_impl_trait(&mut self, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Opaque(preds) => {
+                tested_by!(insert_vars_for_impl_trait);
+                let var = self.table.new_type_var();
+                let var_subst = Substs::builder(1).push(var.clone()).build();
+                self.obligations.extend(
+                    preds
+                        .iter()
+                        .map(|pred| pred.clone().subst_bound_vars(&var_subst))
+                        .filter_map(Obligation::from_predicate),
+                );
+                var
             }
-
-            _ => false,
-        }
-    }
-
-    fn new_type_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_integer_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_float_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_maybe_never_type_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::MaybeNeverTypeVar(
-            self.var_unification_table.new_key(TypeVarValue::Unknown),
-        ))
+            _ => ty,
+        })
     }
 
     /// Replaces Ty::Unknown by a new type var, so we can maybe still infer it.
     fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
         match ty {
-            Ty::Unknown => self.new_type_var(),
+            Ty::Unknown => self.table.new_type_var(),
             Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(Uncertain::Unknown), .. }) => {
-                self.new_integer_var()
+                self.table.new_integer_var()
             }
             Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(Uncertain::Unknown), .. }) => {
-                self.new_float_var()
+                self.table.new_float_var()
             }
             _ => ty,
         }
@@ -402,64 +349,52 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
     }
 
+    fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        self.table.unify(ty1, ty2)
+    }
+
     /// Resolves the type as far as currently possible, replacing type variables
     /// by their known types. All types returned by the infer_* functions should
     /// be resolved as far as possible, i.e. contain no type variables with
     /// known type.
-    fn resolve_ty_as_possible(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+    fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
         self.resolve_obligations_as_possible();
 
-        ty.fold(&mut |ty| match ty {
-            Ty::Infer(tv) => {
-                let inner = tv.to_inner();
-                if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_as_possible);
-                    // recursive type
-                    return tv.fallback_value();
-                }
-                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());
-                    tv_stack.pop();
-                    result
-                } else {
-                    ty
-                }
-            }
-            _ => ty,
-        })
+        self.table.resolve_ty_as_possible(ty)
     }
 
-    /// If `ty` is a type variable with known type, returns that type;
-    /// otherwise, return ty.
     fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
-        let mut ty = Cow::Borrowed(ty);
-        // The type variable could resolve to a int/float variable. Hence try
-        // resolving up to three times; each type of variable shouldn't occur
-        // more than once
-        for i in 0..3 {
-            if i > 0 {
-                tested_by!(type_var_resolves_to_int_var);
-            }
-            match &*ty {
-                Ty::Infer(tv) => {
-                    let inner = tv.to_inner();
-                    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());
-                        }
-                        _ => return ty,
-                    }
-                }
-                _ => return ty,
+        self.table.resolve_ty_shallow(ty)
+    }
+
+    fn resolve_associated_type(&mut self, inner_ty: Ty, assoc_ty: Option<TypeAliasId>) -> Ty {
+        self.resolve_associated_type_with_params(inner_ty, assoc_ty, &[])
+    }
+
+    fn resolve_associated_type_with_params(
+        &mut self,
+        inner_ty: Ty,
+        assoc_ty: Option<TypeAliasId>,
+        params: &[Ty],
+    ) -> Ty {
+        match assoc_ty {
+            Some(res_assoc_ty) => {
+                let ty = self.table.new_type_var();
+                let builder = Substs::build_for_def(self.db, res_assoc_ty)
+                    .push(inner_ty)
+                    .fill(params.iter().cloned());
+                let projection = ProjectionPredicate {
+                    ty: ty.clone(),
+                    projection_ty: ProjectionTy {
+                        associated_ty: res_assoc_ty,
+                        parameters: builder.build(),
+                    },
+                };
+                self.obligations.push(Obligation::Projection(projection));
+                self.resolve_ty_as_possible(ty)
             }
+            None => Ty::Unknown,
         }
-        log::error!("Inference variable still not resolved: {:?}", ty);
-        ty
     }
 
     /// Recurses through the given type, normalizing associated types mentioned
@@ -469,7 +404,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// call). `make_ty` handles this already, but e.g. for field types we need
     /// to do it as well.
     fn normalize_associated_types_in(&mut self, ty: Ty) -> Ty {
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(ty);
         ty.fold(&mut |ty| match ty {
             Ty::Projection(proj_ty) => self.normalize_projection_ty(proj_ty),
             _ => ty,
@@ -477,40 +412,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     }
 
     fn normalize_projection_ty(&mut self, proj_ty: ProjectionTy) -> Ty {
-        let var = self.new_type_var();
+        let var = self.table.new_type_var();
         let predicate = ProjectionPredicate { projection_ty: proj_ty, ty: var.clone() };
         let obligation = Obligation::Projection(predicate);
         self.obligations.push(obligation);
         var
     }
 
-    /// Resolves the type completely; type variables without known type are
-    /// replaced by Ty::Unknown.
-    fn resolve_ty_completely(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
-        ty.fold(&mut |ty| match ty {
-            Ty::Infer(tv) => {
-                let inner = tv.to_inner();
-                if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_completely);
-                    // recursive type
-                    return tv.fallback_value();
-                }
-                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());
-                    tv_stack.pop();
-                    result
-                } else {
-                    tv.fallback_value()
-                }
-            }
-            _ => ty,
-        })
-    }
-
     fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantId>) {
         let path = match path {
             Some(path) => path,
@@ -519,7 +427,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let resolver = &self.resolver;
         // FIXME: this should resolve assoc items as well, see this example:
         // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
-        match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
+        match resolver.resolve_path_in_type_ns_fully(self.db, path.mod_path()) {
             Some(TypeNs::AdtId(AdtId::StructId(strukt))) => {
                 let substs = Ty::substs_from_path(self.db, resolver, path, strukt.into());
                 let ty = self.db.ty(strukt.into());
@@ -547,93 +455,90 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
             self.infer_pat(*pat, &ty, BindingMode::default());
         }
-        self.return_ty = self.make_ty(&data.ret_type);
+        let return_ty = self.make_ty(&data.ret_type);
+        self.return_ty = self.insert_vars_for_impl_trait(return_ty);
     }
 
     fn infer_body(&mut self) {
-        self.infer_expr(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
+        self.infer_expr_coerce(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
     }
 
     fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
-        let path = known::std_iter_into_iterator();
+        let path = path![std::iter::IntoIterator];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::ITEM_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Item])
     }
 
     fn resolve_ops_try_ok(&self) -> Option<TypeAliasId> {
-        let path = known::std_ops_try();
+        let path = path![std::ops::Try];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Ok])
+    }
+
+    fn resolve_ops_neg_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Neg];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
+    }
+
+    fn resolve_ops_not_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Not];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::OK_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 
     fn resolve_future_future_output(&self) -> Option<TypeAliasId> {
-        let path = known::std_future_future();
+        let path = path![std::future::Future];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::OUTPUT_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 
     fn resolve_boxed_box(&self) -> Option<AdtId> {
-        let path = known::std_boxed_box();
+        let path = path![std::boxed::Box];
         let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
         Some(struct_.into())
     }
-}
-
-/// The ID of a type variable.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub struct TypeVarId(pub(super) u32);
-
-impl UnifyKey for TypeVarId {
-    type Value = TypeVarValue;
 
-    fn index(&self) -> u32 {
-        self.0
+    fn resolve_range_full(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeFull];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
 
-    fn from_index(i: u32) -> Self {
-        TypeVarId(i)
+    fn resolve_range(&self) -> Option<AdtId> {
+        let path = path![std::ops::Range];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
 
-    fn tag() -> &'static str {
-        "TypeVarId"
+    fn resolve_range_inclusive(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeInclusive];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
-}
-
-/// The value of a type variable: either we already know the type, or we don't
-/// know it yet.
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum TypeVarValue {
-    Known(Ty),
-    Unknown,
-}
 
-impl TypeVarValue {
-    fn known(&self) -> Option<&Ty> {
-        match self {
-            TypeVarValue::Known(ty) => Some(ty),
-            TypeVarValue::Unknown => None,
-        }
+    fn resolve_range_from(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeFrom];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
-}
 
-impl UnifyValue for TypeVarValue {
-    type Error = NoError;
-
-    fn unify_values(value1: &Self, value2: &Self) -> Result<Self, NoError> {
-        match (value1, value2) {
-            // We should never equate two type variables, both of which have
-            // known types. Instead, we recursively equate those types.
-            (TypeVarValue::Known(t1), TypeVarValue::Known(t2)) => panic!(
-                "equating two type variables, both of which have known types: {:?} and {:?}",
-                t1, t2
-            ),
+    fn resolve_range_to(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeTo];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
+    }
 
-            // If one side is known, prefer that one.
-            (TypeVarValue::Known(..), TypeVarValue::Unknown) => Ok(value1.clone()),
-            (TypeVarValue::Unknown, TypeVarValue::Known(..)) => Ok(value2.clone()),
+    fn resolve_range_to_inclusive(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeToInclusive];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
+    }
 
-            (TypeVarValue::Unknown, TypeVarValue::Unknown) => Ok(TypeVarValue::Unknown),
-        }
+    fn resolve_ops_index_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Index];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 }
 
@@ -643,14 +548,14 @@ impl UnifyValue for TypeVarValue {
 /// several integer types).
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub enum InferTy {
-    TypeVar(TypeVarId),
-    IntVar(TypeVarId),
-    FloatVar(TypeVarId),
-    MaybeNeverTypeVar(TypeVarId),
+    TypeVar(unify::TypeVarId),
+    IntVar(unify::TypeVarId),
+    FloatVar(unify::TypeVarId),
+    MaybeNeverTypeVar(unify::TypeVarId),
 }
 
 impl InferTy {
-    fn to_inner(self) -> TypeVarId {
+    fn to_inner(self) -> unify::TypeVarId {
         match self {
             InferTy::TypeVar(ty)
             | InferTy::IntVar(ty)
@@ -693,7 +598,7 @@ impl Expectation {
 }
 
 mod diagnostics {
-    use hir_def::{expr::ExprId, FunctionId, HasSource, Lookup};
+    use hir_def::{expr::ExprId, src::HasSource, FunctionId, Lookup};
     use hir_expand::diagnostics::DiagnosticSink;
 
     use crate::{db::HirDatabase, diagnostics::NoSuchField};
diff --git a/crates/ra_hir_ty/src/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 719a0f395..83c0c2c3f 100644
--- a/crates/ra_hir_ty/src/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -8,9 +8,9 @@ use hir_def::{lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutabilit
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
-use crate::{autoderef, db::HirDatabase, ImplTy, Substs, Ty, TypeCtor, TypeWalk};
+use crate::{autoderef, db::HirDatabase, Substs, Ty, TypeCtor, TypeWalk};
 
-use super::{InEnvironment, InferTy, InferenceContext, TypeVarValue};
+use super::{unify::TypeVarValue, InEnvironment, InferTy, InferenceContext};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// Unify two types, but may coerce the first one to the second one
@@ -54,10 +54,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         impls
             .iter()
             .filter_map(|&impl_id| {
-                let trait_ref = match db.impl_ty(impl_id) {
-                    ImplTy::TraitRef(it) => it,
-                    ImplTy::Inherent(_) => return None,
-                };
+                let trait_ref = db.impl_trait(impl_id)?;
 
                 // `CoerseUnsized` has one generic parameter for the target type.
                 let cur_from_ty = trait_ref.substs.0.get(0)?;
@@ -88,8 +85,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         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));
+                let var = self.table.new_maybe_never_type_var();
+                self.table.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
                 return true;
             }
             (ty_app!(TypeCtor::Never), _) => return true,
@@ -97,7 +94,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             // 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) {
+                if self.table.unify_inner_trivial(&from_ty, &to_ty) {
                     return true;
                 }
             }
@@ -137,6 +134,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
             }
 
+            (ty_app!(TypeCtor::Closure { .. }, params), ty_app!(TypeCtor::FnPtr { .. })) => {
+                from_ty = params[0].clone();
+            }
+
             _ => {}
         }
 
@@ -333,9 +334,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // 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);
+                    return self.table.unify_substs(st1, st2, 0);
+                }
+                _ => {
+                    if self.table.unify_inner_trivial(&derefed_ty, &to_ty) {
+                        return true;
+                    }
                 }
-                _ => {}
             }
         }
 
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 2f9ca4bbb..3af05394c 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -6,17 +6,21 @@ use std::sync::Arc;
 use hir_def::{
     builtin_type::Signedness,
     expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
-    generics::GenericParams,
     path::{GenericArg, GenericArgs},
     resolver::resolver_for_expr,
-    AdtId, ContainerId, Lookup, StructFieldId,
+    AdtId, AssocContainerId, Lookup, StructFieldId,
 };
-use hir_expand::name::{self, Name};
+use hir_expand::name::{name, Name};
+use ra_syntax::ast::RangeOp;
 
 use crate::{
-    autoderef, db::HirDatabase, method_resolution, op, traits::InEnvironment, utils::variant_data,
-    CallableDef, InferTy, IntTy, Mutability, Obligation, ProjectionPredicate, ProjectionTy, Substs,
-    TraitRef, Ty, TypeCtor, TypeWalk, Uncertain,
+    autoderef,
+    db::HirDatabase,
+    method_resolution, op,
+    traits::InEnvironment,
+    utils::{generics, variant_data, Generics},
+    ApplicationTy, CallableDef, InferTy, IntTy, Mutability, Obligation, Substs, TraitRef, Ty,
+    TypeCtor, TypeWalk, Uncertain,
 };
 
 use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
@@ -31,13 +35,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
             );
         }
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(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 {
+    pub(super) 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
@@ -52,7 +56,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             expected.ty.clone()
         };
 
-        self.resolve_ty_as_possible(&mut vec![], ty)
+        self.resolve_ty_as_possible(ty)
     }
 
     fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
@@ -91,27 +95,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             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,
-                };
+                let pat_ty =
+                    self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
 
                 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 } => {
+            Expr::Lambda { body, args, ret_type, arg_types } => {
                 assert_eq!(args.len(), arg_types.len());
 
                 let mut sig_tys = Vec::new();
@@ -127,7 +118,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
 
                 // add return type
-                let ret_ty = self.new_type_var();
+                let ret_ty = match ret_type {
+                    Some(type_ref) => self.make_ty(type_ref),
+                    None => self.table.new_type_var(),
+                };
                 sig_tys.push(ret_ty.clone());
                 let sig_ty = Ty::apply(
                     TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
@@ -143,7 +137,12 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // infer the body.
                 self.coerce(&closure_ty, &expected.ty);
 
-                self.infer_expr(*body, &Expectation::has_type(ret_ty));
+                let prev_ret_ty = std::mem::replace(&mut self.return_ty, ret_ty.clone());
+
+                self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+
+                self.return_ty = prev_ret_ty;
+
                 closure_ty
             }
             Expr::Call { callee, args } => {
@@ -166,7 +165,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::Match { expr, arms } => {
                 let input_ty = self.infer_expr(*expr, &Expectation::none());
 
-                let mut result_ty = self.new_maybe_never_type_var();
+                let mut result_ty = self.table.new_maybe_never_type_var();
 
                 for arm in arms {
                     for &pat in &arm.pats {
@@ -200,7 +199,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
             Expr::Return { expr } => {
                 if let Some(expr) = expr {
-                    self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
+                    self.infer_expr_coerce(*expr, &Expectation::has_type(self.return_ty.clone()));
+                } else {
+                    let unit = Ty::unit();
+                    self.coerce(&unit, &self.return_ty.clone());
                 }
                 Ty::simple(TypeCtor::Never)
             }
@@ -244,7 +246,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 ty
             }
             Expr::Field { expr, name } => {
-                let receiver_ty = self.infer_expr(*expr, &Expectation::none());
+                let receiver_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
                 let ty = autoderef::autoderef(
                     self.db,
@@ -279,45 +281,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 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,
-                };
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
+                let ty =
+                    self.resolve_associated_type(inner_ty, self.resolve_future_future_output());
                 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,
-                };
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
+                let ty = self.resolve_associated_type(inner_ty, self.resolve_ops_try_ok());
                 ty
             }
             Expr::Cast { expr, type_ref } => {
-                let _inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let _inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 let cast_ty = self.make_ty(type_ref);
                 // FIXME check the cast...
                 cast_ty
@@ -333,12 +308,11 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     } else {
                         Expectation::none()
                     };
-                // FIXME reference coercions etc.
-                let inner_ty = self.infer_expr(*expr, &expectation);
+                let inner_ty = self.infer_expr_inner(*expr, &expectation);
                 Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
             }
             Expr::Box { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 if let Some(box_) = self.resolve_boxed_box() {
                     Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
                 } else {
@@ -346,7 +320,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
             }
             Expr::UnaryOp { expr, op } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 match op {
                     UnaryOp::Deref => match self.resolver.krate() {
                         Some(krate) => {
@@ -369,31 +343,36 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     },
                     UnaryOp::Neg => {
                         match &inner_ty {
-                            Ty::Apply(a_ty) => match a_ty.ctor {
-                                TypeCtor::Int(Uncertain::Unknown)
-                                | TypeCtor::Int(Uncertain::Known(IntTy {
-                                    signedness: 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,
+                            // Fast path for builtins
+                            Ty::Apply(ApplicationTy {
+                                ctor:
+                                    TypeCtor::Int(Uncertain::Known(IntTy {
+                                        signedness: Signedness::Signed,
+                                        ..
+                                    })),
+                                ..
+                            })
+                            | Ty::Apply(ApplicationTy {
+                                ctor: TypeCtor::Int(Uncertain::Unknown),
+                                ..
+                            })
+                            | Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(_), .. })
+                            | Ty::Infer(InferTy::IntVar(..))
+                            | Ty::Infer(InferTy::FloatVar(..)) => inner_ty,
+                            // Otherwise we resolve via the std::ops::Neg trait
+                            _ => self
+                                .resolve_associated_type(inner_ty, self.resolve_ops_neg_output()),
                         }
                     }
                     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,
+                            // Fast path for builtins
+                            Ty::Apply(ApplicationTy { ctor: TypeCtor::Bool, .. })
+                            | Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(_), .. })
+                            | Ty::Infer(InferTy::IntVar(..)) => inner_ty,
+                            // Otherwise we resolve via the std::ops::Not trait
+                            _ => self
+                                .resolve_associated_type(inner_ty, self.resolve_ops_not_output()),
                         }
                     }
                 }
@@ -415,21 +394,63 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
                 _ => Ty::Unknown,
             },
+            Expr::Range { lhs, rhs, range_type } => {
+                let lhs_ty = lhs.map(|e| self.infer_expr_inner(e, &Expectation::none()));
+                let rhs_expect = lhs_ty
+                    .as_ref()
+                    .map_or_else(Expectation::none, |ty| Expectation::has_type(ty.clone()));
+                let rhs_ty = rhs.map(|e| self.infer_expr(e, &rhs_expect));
+                match (range_type, lhs_ty, rhs_ty) {
+                    (RangeOp::Exclusive, None, None) => match self.resolve_range_full() {
+                        Some(adt) => Ty::simple(TypeCtor::Adt(adt)),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Exclusive, None, Some(ty)) => match self.resolve_range_to() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, None, Some(ty)) => {
+                        match self.resolve_range_to_inclusive() {
+                            Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                            None => Ty::Unknown,
+                        }
+                    }
+                    (RangeOp::Exclusive, Some(_), Some(ty)) => match self.resolve_range() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, Some(_), Some(ty)) => {
+                        match self.resolve_range_inclusive() {
+                            Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                            None => Ty::Unknown,
+                        }
+                    }
+                    (RangeOp::Exclusive, Some(ty), None) => match self.resolve_range_from() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, _, None) => 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
+                let base_ty = self.infer_expr_inner(*base, &Expectation::none());
+                let index_ty = self.infer_expr(*index, &Expectation::none());
+
+                self.resolve_associated_type_with_params(
+                    base_ty,
+                    self.resolve_ops_index_output(),
+                    &[index_ty],
+                )
             }
             Expr::Tuple { exprs } => {
                 let mut tys = match &expected.ty {
                     ty_app!(TypeCtor::Tuple { .. }, st) => st
                         .iter()
                         .cloned()
-                        .chain(repeat_with(|| self.new_type_var()))
+                        .chain(repeat_with(|| self.table.new_type_var()))
                         .take(exprs.len())
                         .collect::<Vec<_>>(),
-                    _ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
+                    _ => (0..exprs.len()).map(|_| self.table.new_type_var()).collect(),
                 };
 
                 for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
@@ -443,7 +464,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
                         st.as_single().clone()
                     }
-                    _ => self.new_type_var(),
+                    _ => self.table.new_type_var(),
                 };
 
                 match array {
@@ -485,7 +506,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         };
         // 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);
+        let ty = self.resolve_ty_as_possible(ty);
         self.write_expr_ty(tgt_expr, ty.clone());
         ty
     }
@@ -514,7 +535,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         }
                     }
 
-                    let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+                    let ty = self.resolve_ty_as_possible(ty);
                     self.infer_pat(*pat, &ty, BindingMode::default());
                 }
                 Statement::Expr(expr) => {
@@ -558,7 +579,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Some((ty, func)) => {
                 let ty = canonicalized_receiver.decanonicalize_ty(ty);
                 self.write_method_resolution(tgt_expr, func);
-                (ty, self.db.value_ty(func.into()), Some(self.db.generic_params(func.into())))
+                (ty, self.db.value_ty(func.into()), Some(generics(self.db, func.into())))
             }
             None => (receiver_ty, Ty::Unknown, None),
         };
@@ -607,6 +628,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     continue;
                 }
 
+                let param_ty = self.insert_vars_for_impl_trait(param_ty);
                 let param_ty = self.normalize_associated_types_in(param_ty);
                 self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
             }
@@ -615,17 +637,17 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
     fn substs_for_method_call(
         &mut self,
-        def_generics: Option<Arc<GenericParams>>,
+        def_generics: Option<Generics>,
         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);
+        let (total_len, _parent_len, child_len) =
+            def_generics.as_ref().map_or((0, 0, 0), |g| g.len_split());
+        let mut substs = Vec::with_capacity(total_len);
         // 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 {
+        if let Some(parent_generics) = def_generics.as_ref().map(|p| p.iter_parent()) {
+            for (_id, param) in parent_generics {
+                if param.name == name![Self] {
                     substs.push(receiver_ty.clone());
                 } else {
                     substs.push(Ty::Unknown);
@@ -635,7 +657,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         // 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) {
+            for arg in generic_args.args.iter().take(child_len) {
                 match arg {
                     GenericArg::Type(type_ref) => {
                         let ty = self.make_ty(type_ref);
@@ -645,10 +667,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
         };
         let supplied_params = substs.len();
-        for _ in supplied_params..parent_param_count + param_count {
+        for _ in supplied_params..total_len {
             substs.push(Ty::Unknown);
         }
-        assert_eq!(substs.len(), parent_param_count + param_count);
+        assert_eq!(substs.len(), total_len);
         Substs(substs.into())
     }
 
@@ -665,13 +687,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // add obligation for trait implementation, if this is a trait method
                 match def {
                     CallableDef::FunctionId(f) => {
-                        if let ContainerId::TraitId(trait_) = f.lookup(self.db).container {
+                        if let AssocContainerId::TraitId(trait_) = f.lookup(self.db).container {
                             // construct a TraitDef
-                            let substs = a_ty.parameters.prefix(
-                                self.db
-                                    .generic_params(trait_.into())
-                                    .count_params_including_parent(),
-                            );
+                            let substs =
+                                a_ty.parameters.prefix(generics(self.db, trait_.into()).len());
                             self.obligations.push(Obligation::Trait(TraitRef {
                                 trait_: trait_.into(),
                                 substs,
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 1ebb36239..a14662884 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -170,7 +170,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     }
                     BindingMode::Move => inner_ty.clone(),
                 };
-                let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
+                let bound_ty = self.resolve_ty_as_possible(bound_ty);
                 self.write_pat_ty(pat, bound_ty);
                 return inner_ty;
             }
@@ -179,7 +179,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         // 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);
+        let ty = self.resolve_ty_as_possible(ty);
         self.write_pat_ty(pat, ty.clone());
         ty
     }
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 14be66836..ffd358367 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -1,9 +1,11 @@
 //! Path expression resolution.
 
+use std::iter;
+
 use hir_def::{
-    path::{Path, PathKind, PathSegment},
+    path::{Path, PathSegment},
     resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
-    AssocItemId, ContainerId, Lookup,
+    AssocContainerId, AssocItemId, Lookup,
 };
 use hir_expand::name::Name;
 
@@ -30,21 +32,21 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         path: &Path,
         id: ExprOrPatId,
     ) -> Option<Ty> {
-        let (value, self_subst) = if let PathKind::Type(type_ref) = &path.kind {
-            if path.segments.is_empty() {
+        let (value, self_subst) = if let Some(type_ref) = path.type_anchor() {
+            if path.segments().is_empty() {
                 // This can't actually happen syntax-wise
                 return None;
             }
             let ty = self.make_ty(type_ref);
-            let remaining_segments_for_ty = &path.segments[..path.segments.len() - 1];
+            let remaining_segments_for_ty = path.segments().take(path.segments().len() - 1);
             let ty = Ty::from_type_relative_path(self.db, resolver, ty, remaining_segments_for_ty);
             self.resolve_ty_assoc_item(
                 ty,
-                &path.segments.last().expect("path had at least one segment").name,
+                &path.segments().last().expect("path had at least one segment").name,
                 id,
             )?
         } else {
-            let value_or_partial = resolver.resolve_path_in_value_ns(self.db, &path)?;
+            let value_or_partial = resolver.resolve_path_in_value_ns(self.db, path.mod_path())?;
 
             match value_or_partial {
                 ResolveValueResult::ValueNs(it) => (it, None),
@@ -57,7 +59,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let typable: ValueTyDefId = match value {
             ValueNs::LocalBinding(pat) => {
                 let ty = self.result.type_of_pat.get(pat)?.clone();
-                let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+                let ty = self.resolve_ty_as_possible(ty);
                 return Some(ty);
             }
             ValueNs::FunctionId(it) => it.into(),
@@ -83,13 +85,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         remaining_index: usize,
         id: ExprOrPatId,
     ) -> Option<(ValueNs, Option<Substs>)> {
-        assert!(remaining_index < path.segments.len());
+        assert!(remaining_index < path.segments().len());
         // there may be more intermediate segments between the resolved one and
         // the end. Only the last segment needs to be resolved to a value; from
         // the segments before that, we need to get either a type or a trait ref.
 
-        let resolved_segment = &path.segments[remaining_index - 1];
-        let remaining_segments = &path.segments[remaining_index..];
+        let resolved_segment = path.segments().get(remaining_index - 1).unwrap();
+        let remaining_segments = path.segments().skip(remaining_index);
         let is_before_last = remaining_segments.len() == 1;
 
         match (def, is_before_last) {
@@ -110,7 +112,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // trait but it's not the last segment, so the next segment
                 // should resolve to an associated type of that trait (e.g. `<T
                 // as Iterator>::Item::default`)
-                let remaining_segments_for_ty = &remaining_segments[..remaining_segments.len() - 1];
+                let remaining_segments_for_ty =
+                    remaining_segments.take(remaining_segments.len() - 1);
                 let ty = Ty::from_partly_resolved_hir_path(
                     self.db,
                     &self.resolver,
@@ -136,7 +139,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn resolve_trait_assoc_item(
         &mut self,
         trait_ref: TraitRef,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         id: ExprOrPatId,
     ) -> Option<(ValueNs, Option<Substs>)> {
         let trait_ = trait_ref.trait_;
@@ -148,7 +151,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             .map(|(_name, id)| (*id).into())
             .find_map(|item| match item {
                 AssocItemId::FunctionId(func) => {
-                    if segment.name == self.db.function_data(func).name {
+                    if segment.name == &self.db.function_data(func).name {
                         Some(AssocItemId::FunctionId(func))
                     } else {
                         None
@@ -156,7 +159,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
 
                 AssocItemId::ConstId(konst) => {
-                    if self.db.const_data(konst).name.as_ref().map_or(false, |n| n == &segment.name)
+                    if self.db.const_data(konst).name.as_ref().map_or(false, |n| n == segment.name)
                     {
                         Some(AssocItemId::ConstId(konst))
                     } else {
@@ -206,12 +209,23 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     AssocItemId::TypeAliasId(_) => unreachable!(),
                 };
                 let substs = match container {
-                    ContainerId::ImplId(_) => self.find_self_types(&def, ty.clone()),
-                    ContainerId::TraitId(trait_) => {
+                    AssocContainerId::ImplId(impl_id) => {
+                        let impl_substs = Substs::build_for_def(self.db, impl_id)
+                            .fill(iter::repeat_with(|| self.table.new_type_var()))
+                            .build();
+                        let impl_self_ty = self.db.impl_self_ty(impl_id).subst(&impl_substs);
+                        let substs = Substs::build_for_def(self.db, item)
+                            .use_parent_substs(&impl_substs)
+                            .fill_with_params()
+                            .build();
+                        self.unify(&impl_self_ty, &ty);
+                        Some(substs)
+                    }
+                    AssocContainerId::TraitId(trait_) => {
                         // we're picking this method
                         let trait_substs = Substs::build_for_def(self.db, trait_)
                             .push(ty.clone())
-                            .fill(std::iter::repeat_with(|| self.new_type_var()))
+                            .fill(std::iter::repeat_with(|| self.table.new_type_var()))
                             .build();
                         let substs = Substs::build_for_def(self.db, item)
                             .use_parent_substs(&trait_substs)
@@ -223,7 +237,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         }));
                         Some(substs)
                     }
-                    ContainerId::ModuleId(_) => None,
+                    AssocContainerId::ContainerId(_) => None,
                 };
 
                 self.write_assoc_resolution(id, item.into());
@@ -231,38 +245,4 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             },
         )
     }
-
-    fn find_self_types(&self, def: &ValueNs, actual_def_ty: Ty) -> Option<Substs> {
-        if let ValueNs::FunctionId(func) = *def {
-            // We only do the infer if parent has generic params
-            let gen = self.db.generic_params(func.into());
-            if gen.count_parent_params() == 0 {
-                return None;
-            }
-
-            let impl_id = match func.lookup(self.db).container {
-                ContainerId::ImplId(it) => it,
-                _ => return None,
-            };
-            let self_ty = self.db.impl_ty(impl_id).self_type().clone();
-            let self_ty_substs = self_ty.substs()?;
-            let actual_substs = actual_def_ty.substs()?;
-
-            let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
-
-            // The following code *link up* the function actual parma type
-            // and impl_block type param index
-            self_ty_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
-                if let Ty::Param { idx, .. } = param {
-                    if let Some(s) = new_substs.get_mut(*idx as usize) {
-                        *s = pty.clone();
-                    }
-                }
-            });
-
-            Some(Substs(new_substs.into()))
-        } else {
-            None
-        }
-    }
 }
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index f3a875678..fe05642ae 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -1,9 +1,15 @@
 //! Unification and canonicalization logic.
 
+use std::borrow::Cow;
+
+use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
+
+use test_utils::tested_by;
+
 use super::{InferenceContext, Obligation};
 use crate::{
     db::HirDatabase, utils::make_mut_slice, Canonical, InEnvironment, InferTy, ProjectionPredicate,
-    ProjectionTy, Substs, TraitRef, Ty, TypeWalk,
+    ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
@@ -24,7 +30,7 @@ where
     /// A stack of type variables that is used to detect recursive types (which
     /// are an error, but we need to protect against them to avoid stack
     /// overflows).
-    var_stack: Vec<super::TypeVarId>,
+    var_stack: Vec<TypeVarId>,
 }
 
 pub(super) struct Canonicalized<T> {
@@ -53,14 +59,14 @@ where
                     return tv.fallback_value();
                 }
                 if let Some(known_ty) =
-                    self.ctx.var_unification_table.inlined_probe_value(inner).known()
+                    self.ctx.table.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();
                     result
                 } else {
-                    let root = self.ctx.var_unification_table.find(inner);
+                    let root = self.ctx.table.var_unification_table.find(inner);
                     let free_var = match tv {
                         InferTy::TypeVar(_) => InferTy::TypeVar(root),
                         InferTy::IntVar(_) => InferTy::IntVar(root),
@@ -153,10 +159,268 @@ impl<T> Canonicalized<T> {
         solution: Canonical<Vec<Ty>>,
     ) {
         // the solution may contain new variables, which we need to convert to new inference vars
-        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.new_type_var()).collect());
+        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.table.new_type_var()).collect());
         for (i, ty) in solution.value.into_iter().enumerate() {
             let var = self.free_vars[i];
-            ctx.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
+            ctx.table.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
+        }
+    }
+}
+
+pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
+    let mut table = InferenceTable::new();
+    let vars =
+        Substs::builder(ty1.num_vars).fill(std::iter::repeat_with(|| table.new_type_var())).build();
+    let ty_with_vars = ty1.value.clone().subst_bound_vars(&vars);
+    if !table.unify(&ty_with_vars, &ty2.value) {
+        return None;
+    }
+    Some(
+        Substs::builder(ty1.num_vars)
+            .fill(vars.iter().map(|v| table.resolve_ty_completely(v.clone())))
+            .build(),
+    )
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct InferenceTable {
+    pub(super) var_unification_table: InPlaceUnificationTable<TypeVarId>,
+}
+
+impl InferenceTable {
+    pub fn new() -> Self {
+        InferenceTable { var_unification_table: InPlaceUnificationTable::new() }
+    }
+
+    pub fn new_type_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_integer_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_float_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_maybe_never_type_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::MaybeNeverTypeVar(
+            self.var_unification_table.new_key(TypeVarValue::Unknown),
+        ))
+    }
+
+    pub fn resolve_ty_completely(&mut self, ty: Ty) -> Ty {
+        self.resolve_ty_completely_inner(&mut Vec::new(), ty)
+    }
+
+    pub fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
+        self.resolve_ty_as_possible_inner(&mut Vec::new(), ty)
+    }
+
+    pub fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        self.unify_inner(ty1, ty2, 0)
+    }
+
+    pub fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
+        substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
+    }
+
+    fn unify_inner(&mut self, ty1: &Ty, ty2: &Ty, depth: usize) -> bool {
+        if depth > 1000 {
+            // prevent stackoverflows
+            panic!("infinite recursion in unification");
+        }
+        if ty1 == ty2 {
+            return true;
+        }
+        // try to resolve type vars first
+        let ty1 = self.resolve_ty_shallow(ty1);
+        let ty2 = self.resolve_ty_shallow(ty2);
+        match (&*ty1, &*ty2) {
+            (Ty::Apply(a_ty1), Ty::Apply(a_ty2)) if a_ty1.ctor == a_ty2.ctor => {
+                self.unify_substs(&a_ty1.parameters, &a_ty2.parameters, depth + 1)
+            }
+            _ => self.unify_inner_trivial(&ty1, &ty2),
+        }
+    }
+
+    pub(super) fn unify_inner_trivial(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        match (ty1, ty2) {
+            (Ty::Unknown, _) | (_, Ty::Unknown) => true,
+
+            (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
+            | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
+            | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
+            | (
+                Ty::Infer(InferTy::MaybeNeverTypeVar(tv1)),
+                Ty::Infer(InferTy::MaybeNeverTypeVar(tv2)),
+            ) => {
+                // both type vars are unknown since we tried to resolve them
+                self.var_unification_table.union(*tv1, *tv2);
+                true
+            }
+
+            // The order of MaybeNeverTypeVar matters here.
+            // Unifying MaybeNeverTypeVar and TypeVar will let the latter become MaybeNeverTypeVar.
+            // Unifying MaybeNeverTypeVar and other concrete type will let the former become it.
+            (Ty::Infer(InferTy::TypeVar(tv)), other)
+            | (other, Ty::Infer(InferTy::TypeVar(tv)))
+            | (Ty::Infer(InferTy::MaybeNeverTypeVar(tv)), other)
+            | (other, Ty::Infer(InferTy::MaybeNeverTypeVar(tv)))
+            | (Ty::Infer(InferTy::IntVar(tv)), other @ ty_app!(TypeCtor::Int(_)))
+            | (other @ ty_app!(TypeCtor::Int(_)), Ty::Infer(InferTy::IntVar(tv)))
+            | (Ty::Infer(InferTy::FloatVar(tv)), other @ ty_app!(TypeCtor::Float(_)))
+            | (other @ ty_app!(TypeCtor::Float(_)), Ty::Infer(InferTy::FloatVar(tv))) => {
+                // the type var is unknown since we tried to resolve it
+                self.var_unification_table.union_value(*tv, TypeVarValue::Known(other.clone()));
+                true
+            }
+
+            _ => false,
+        }
+    }
+
+    /// If `ty` is a type variable with known type, returns that type;
+    /// otherwise, return ty.
+    pub fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
+        let mut ty = Cow::Borrowed(ty);
+        // The type variable could resolve to a int/float variable. Hence try
+        // resolving up to three times; each type of variable shouldn't occur
+        // more than once
+        for i in 0..3 {
+            if i > 0 {
+                tested_by!(type_var_resolves_to_int_var);
+            }
+            match &*ty {
+                Ty::Infer(tv) => {
+                    let inner = tv.to_inner();
+                    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());
+                        }
+                        _ => return ty,
+                    }
+                }
+                _ => return ty,
+            }
+        }
+        log::error!("Inference variable still not resolved: {:?}", ty);
+        ty
+    }
+
+    /// Resolves the type as far as currently possible, replacing type variables
+    /// by their known types. All types returned by the infer_* functions should
+    /// be resolved as far as possible, i.e. contain no type variables with
+    /// known type.
+    fn resolve_ty_as_possible_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Infer(tv) => {
+                let inner = tv.to_inner();
+                if tv_stack.contains(&inner) {
+                    tested_by!(type_var_cycles_resolve_as_possible);
+                    // recursive type
+                    return tv.fallback_value();
+                }
+                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_inner(tv_stack, known_ty.clone());
+                    tv_stack.pop();
+                    result
+                } else {
+                    ty
+                }
+            }
+            _ => ty,
+        })
+    }
+
+    /// Resolves the type completely; type variables without known type are
+    /// replaced by Ty::Unknown.
+    fn resolve_ty_completely_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Infer(tv) => {
+                let inner = tv.to_inner();
+                if tv_stack.contains(&inner) {
+                    tested_by!(type_var_cycles_resolve_completely);
+                    // recursive type
+                    return tv.fallback_value();
+                }
+                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_inner(tv_stack, known_ty.clone());
+                    tv_stack.pop();
+                    result
+                } else {
+                    tv.fallback_value()
+                }
+            }
+            _ => ty,
+        })
+    }
+}
+
+/// The ID of a type variable.
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub struct TypeVarId(pub(super) u32);
+
+impl UnifyKey for TypeVarId {
+    type Value = TypeVarValue;
+
+    fn index(&self) -> u32 {
+        self.0
+    }
+
+    fn from_index(i: u32) -> Self {
+        TypeVarId(i)
+    }
+
+    fn tag() -> &'static str {
+        "TypeVarId"
+    }
+}
+
+/// The value of a type variable: either we already know the type, or we don't
+/// know it yet.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum TypeVarValue {
+    Known(Ty),
+    Unknown,
+}
+
+impl TypeVarValue {
+    fn known(&self) -> Option<&Ty> {
+        match self {
+            TypeVarValue::Known(ty) => Some(ty),
+            TypeVarValue::Unknown => None,
+        }
+    }
+}
+
+impl UnifyValue for TypeVarValue {
+    type Error = NoError;
+
+    fn unify_values(value1: &Self, value2: &Self) -> Result<Self, NoError> {
+        match (value1, value2) {
+            // We should never equate two type variables, both of which have
+            // known types. Instead, we recursively equate those types.
+            (TypeVarValue::Known(t1), TypeVarValue::Known(t2)) => panic!(
+                "equating two type variables, both of which have known types: {:?} and {:?}",
+                t1, t2
+            ),
+
+            // If one side is known, prefer that one.
+            (TypeVarValue::Known(..), TypeVarValue::Unknown) => Ok(value1.clone()),
+            (TypeVarValue::Unknown, TypeVarValue::Known(..)) => Ok(value2.clone()),
+
+            (TypeVarValue::Unknown, TypeVarValue::Unknown) => Ok(TypeVarValue::Unknown),
         }
     }
 }
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index b45c8f82f..48abf97c9 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -44,8 +44,8 @@ use std::sync::Arc;
 use std::{fmt, iter, mem};
 
 use hir_def::{
-    expr::ExprId, generics::GenericParams, type_ref::Mutability, AdtId, ContainerId, DefWithBodyId,
-    GenericDefId, HasModule, Lookup, TraitId, TypeAliasId,
+    expr::ExprId, type_ref::Mutability, AdtId, AssocContainerId, DefWithBodyId, GenericDefId,
+    HasModule, Lookup, TraitId, TypeAliasId,
 };
 use hir_expand::name::Name;
 use ra_db::{impl_intern_key, salsa, CrateId};
@@ -53,7 +53,7 @@ use ra_db::{impl_intern_key, salsa, CrateId};
 use crate::{
     db::HirDatabase,
     primitive::{FloatTy, IntTy, Uncertain},
-    utils::make_mut_slice,
+    utils::{generics, make_mut_slice, Generics},
 };
 use display::{HirDisplay, HirFormatter};
 
@@ -166,16 +166,16 @@ impl TypeCtor {
             | TypeCtor::Closure { .. } // 1 param representing the signature of the closure
             => 1,
             TypeCtor::Adt(adt) => {
-                let generic_params = db.generic_params(AdtId::from(adt).into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, AdtId::from(adt).into());
+                generic_params.len()
             }
             TypeCtor::FnDef(callable) => {
-                let generic_params = db.generic_params(callable.into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, callable.into());
+                generic_params.len()
             }
             TypeCtor::AssociatedType(type_alias) => {
-                let generic_params = db.generic_params(type_alias.into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, type_alias.into());
+                generic_params.len()
             }
             TypeCtor::FnPtr { num_args } => num_args as usize + 1,
             TypeCtor::Tuple { cardinality } => cardinality as usize,
@@ -251,7 +251,7 @@ impl ProjectionTy {
 
     fn trait_(&self, db: &impl HirDatabase) -> TraitId {
         match self.associated_ty.lookup(db).container {
-            ContainerId::TraitId(it) => it,
+            AssocContainerId::TraitId(it) => it,
             _ => panic!("projection ty without parent trait"),
         }
     }
@@ -364,36 +364,26 @@ impl Substs {
     }
 
     /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
-    pub fn identity(generic_params: &GenericParams) -> Substs {
+    pub(crate) fn identity(generic_params: &Generics) -> Substs {
         Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Param { idx: p.idx, name: p.name.clone() })
-                .collect(),
+            generic_params.iter().map(|(idx, p)| Ty::Param { idx, name: p.name.clone() }).collect(),
         )
     }
 
     /// Return Substs that replace each parameter by a bound variable.
-    pub fn bound_vars(generic_params: &GenericParams) -> Substs {
-        Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Bound(p.idx))
-                .collect(),
-        )
+    pub(crate) fn bound_vars(generic_params: &Generics) -> Substs {
+        Substs(generic_params.iter().map(|(idx, _p)| Ty::Bound(idx)).collect())
     }
 
     pub fn build_for_def(db: &impl HirDatabase, def: impl Into<GenericDefId>) -> SubstsBuilder {
         let def = def.into();
-        let params = db.generic_params(def);
-        let param_count = params.count_params_including_parent();
+        let params = generics(db, def);
+        let param_count = params.len();
         Substs::builder(param_count)
     }
 
-    pub fn build_for_generics(generic_params: &GenericParams) -> SubstsBuilder {
-        Substs::builder(generic_params.count_params_including_parent())
+    pub(crate) fn build_for_generics(generic_params: &Generics) -> SubstsBuilder {
+        Substs::builder(generic_params.len())
     }
 
     pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
@@ -486,21 +476,6 @@ impl TypeWalk for TraitRef {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum ImplTy {
-    Inherent(Ty),
-    TraitRef(TraitRef),
-}
-
-impl ImplTy {
-    pub(crate) fn self_type(&self) -> &Ty {
-        match self {
-            ImplTy::Inherent(it) => it,
-            ImplTy::TraitRef(tr) => &tr.substs[0],
-        }
-    }
-}
-
 /// Like `generics::WherePredicate`, but with resolved types: A condition on the
 /// parameters of a generic item.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -931,13 +906,44 @@ impl HirDisplay for ApplicationTy {
                 write!(f, "{}", name)?;
                 if self.parameters.len() > 0 {
                     write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
+
+                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
+                    let parameters_to_write = if f.should_display_default_types() {
+                        self.parameters.0.as_ref()
+                    } else {
+                        match self
+                            .ctor
+                            .as_generic_def()
+                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
+                            .filter(|defaults| !defaults.is_empty())
+                        {
+                            Option::None => self.parameters.0.as_ref(),
+                            Option::Some(default_parameters) => {
+                                for (i, parameter) in self.parameters.iter().enumerate() {
+                                    match (parameter, default_parameters.get(i)) {
+                                        (&Ty::Unknown, _) | (_, None) => {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        (_, Some(default_parameter))
+                                            if parameter != default_parameter =>
+                                        {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        _ => (),
+                                    }
+                                }
+                                &non_default_parameters
+                            }
+                        }
+                    };
+
+                    f.write_joined(parameters_to_write, ", ")?;
                     write!(f, ">")?;
                 }
             }
             TypeCtor::AssociatedType(type_alias) => {
                 let trait_ = match type_alias.lookup(f.db).container {
-                    ContainerId::TraitId(it) => it,
+                    AssocContainerId::TraitId(it) => it,
                     _ => panic!("not an associated type"),
                 };
                 let trait_name = f.db.trait_data(trait_).name.clone();
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 091c60f4f..af3db2e1d 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -11,10 +11,10 @@ use std::sync::Arc;
 use hir_def::{
     builtin_type::BuiltinType,
     generics::WherePredicate,
-    path::{GenericArg, Path, PathKind, PathSegment},
+    path::{GenericArg, Path, PathSegment, PathSegments},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{TypeBound, TypeRef},
-    AdtId, AstItemDef, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
+    AdtId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
     LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
 };
 use ra_arena::map::ArenaMap;
@@ -24,11 +24,11 @@ use crate::{
     db::HirDatabase,
     primitive::{FloatTy, IntTy},
     utils::{
-        all_super_traits, associated_type_by_name_including_super_traits, make_mut_slice,
+        all_super_traits, associated_type_by_name_including_super_traits, generics, make_mut_slice,
         variant_data,
     },
-    FnSig, GenericPredicate, ImplTy, ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment,
-    TraitRef, Ty, TypeCtor, TypeWalk,
+    FnSig, GenericPredicate, ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef,
+    Ty, TypeCtor, TypeWalk,
 };
 
 impl Ty {
@@ -101,17 +101,19 @@ impl Ty {
             TypeRef::Path(path) => path,
             _ => return None,
         };
-        if let PathKind::Type(_) = &path.kind {
+        if path.type_anchor().is_some() {
             return None;
         }
-        if path.segments.len() > 1 {
+        if path.segments().len() > 1 {
             return None;
         }
-        let resolution = match resolver.resolve_path_in_type_ns(db, path) {
+        let resolution = match resolver.resolve_path_in_type_ns(db, path.mod_path()) {
             Some((it, None)) => it,
             _ => return None,
         };
-        if let TypeNs::GenericParam(idx) = resolution {
+        if let TypeNs::GenericParam(param_id) = resolution {
+            let generics = generics(db, resolver.generic_def().expect("generics in scope"));
+            let idx = generics.param_idx(param_id);
             Some(idx)
         } else {
             None
@@ -122,11 +124,11 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         ty: Ty,
-        remaining_segments: &[PathSegment],
+        remaining_segments: PathSegments<'_>,
     ) -> Ty {
         if remaining_segments.len() == 1 {
             // resolve unselected assoc types
-            let segment = &remaining_segments[0];
+            let segment = remaining_segments.first().unwrap();
             Ty::select_associated_type(db, resolver, ty, segment)
         } else if remaining_segments.len() > 1 {
             // FIXME report error (ambiguous associated type)
@@ -140,15 +142,15 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         resolution: TypeNs,
-        resolved_segment: &PathSegment,
-        remaining_segments: &[PathSegment],
+        resolved_segment: PathSegment<'_>,
+        remaining_segments: PathSegments<'_>,
     ) -> Ty {
         let ty = match resolution {
             TypeNs::TraitId(trait_) => {
                 let trait_ref =
                     TraitRef::from_resolved_path(db, resolver, trait_, resolved_segment, None);
                 return if remaining_segments.len() == 1 {
-                    let segment = &remaining_segments[0];
+                    let segment = remaining_segments.first().unwrap();
                     let associated_ty = associated_type_by_name_including_super_traits(
                         db,
                         trait_ref.trait_,
@@ -174,12 +176,14 @@ impl Ty {
                     Ty::Dyn(Arc::new([GenericPredicate::Implemented(trait_ref)]))
                 };
             }
-            TypeNs::GenericParam(idx) => {
+            TypeNs::GenericParam(param_id) => {
+                let generics = generics(db, resolver.generic_def().expect("generics in scope"));
+                let idx = generics.param_idx(param_id);
                 // FIXME: maybe return name in resolution?
-                let name = resolved_segment.name.clone();
+                let name = generics.param_name(param_id);
                 Ty::Param { idx, name }
             }
-            TypeNs::SelfType(impl_id) => db.impl_ty(impl_id).self_type().clone(),
+            TypeNs::SelfType(impl_id) => db.impl_self_ty(impl_id).clone(),
             TypeNs::AdtSelfType(adt) => db.ty(adt.into()),
 
             TypeNs::AdtId(it) => Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into()),
@@ -198,21 +202,21 @@ impl Ty {
 
     pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Ty {
         // Resolve the path (in type namespace)
-        if let PathKind::Type(type_ref) = &path.kind {
+        if let Some(type_ref) = path.type_anchor() {
             let ty = Ty::from_hir(db, resolver, &type_ref);
-            let remaining_segments = &path.segments[..];
-            return Ty::from_type_relative_path(db, resolver, ty, remaining_segments);
+            return Ty::from_type_relative_path(db, resolver, ty, path.segments());
         }
-        let (resolution, remaining_index) = match resolver.resolve_path_in_type_ns(db, path) {
-            Some(it) => it,
-            None => return Ty::Unknown,
-        };
+        let (resolution, remaining_index) =
+            match resolver.resolve_path_in_type_ns(db, path.mod_path()) {
+                Some(it) => it,
+                None => return Ty::Unknown,
+            };
         let (resolved_segment, remaining_segments) = match remaining_index {
             None => (
-                path.segments.last().expect("resolved path has at least one element"),
-                &[] as &[PathSegment],
+                path.segments().last().expect("resolved path has at least one element"),
+                PathSegments::EMPTY,
             ),
-            Some(i) => (&path.segments[i - 1], &path.segments[i..]),
+            Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
         };
         Ty::from_partly_resolved_hir_path(
             db,
@@ -227,7 +231,7 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         self_ty: Ty,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
     ) -> Ty {
         let param_idx = match self_ty {
             Ty::Param { idx, .. } => idx,
@@ -257,7 +261,7 @@ impl Ty {
     fn from_hir_path_inner(
         db: &impl HirDatabase,
         resolver: &Resolver,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         typable: TyDefId,
     ) -> Ty {
         let generic_def = match typable {
@@ -280,7 +284,7 @@ impl Ty {
         // special-case enum variants
         resolved: ValueTyDefId,
     ) -> Substs {
-        let last = path.segments.last().expect("path should have at least one segment");
+        let last = path.segments().last().expect("path should have at least one segment");
         let (segment, generic_def) = match resolved {
             ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
             ValueTyDefId::StructId(it) => (last, Some(it.into())),
@@ -292,13 +296,11 @@ impl Ty {
                 // referring to the variant. So `Option::<T>::None` and
                 // `Option::None::<T>` are both allowed (though the former is
                 // preferred). See also `def_ids_for_path_segments` in rustc.
-                let len = path.segments.len();
-                let segment = if len >= 2 && path.segments[len - 2].args_and_bindings.is_some() {
-                    // Option::<T>::None
-                    &path.segments[len - 2]
-                } else {
-                    // Option::None::<T>
-                    last
+                let len = path.segments().len();
+                let penultimate = if len >= 2 { path.segments().get(len - 2) } else { None };
+                let segment = match penultimate {
+                    Some(segment) if segment.args_and_bindings.is_some() => segment,
+                    _ => last,
                 };
                 (segment, Some(var.parent.into()))
             }
@@ -310,16 +312,15 @@ impl Ty {
 pub(super) fn substs_from_path_segment(
     db: &impl HirDatabase,
     resolver: &Resolver,
-    segment: &PathSegment,
+    segment: PathSegment<'_>,
     def_generic: Option<GenericDefId>,
     add_self_param: bool,
 ) -> Substs {
     let mut substs = Vec::new();
-    let def_generics = def_generic.map(|def| db.generic_params(def.into()));
+    let def_generics = def_generic.map(|def| generics(db, def.into()));
 
-    let (parent_param_count, param_count) =
-        def_generics.map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
-    substs.extend(iter::repeat(Ty::Unknown).take(parent_param_count));
+    let (total_len, parent_len, child_len) = def_generics.map_or((0, 0, 0), |g| g.len_split());
+    substs.extend(iter::repeat(Ty::Unknown).take(parent_len));
     if add_self_param {
         // FIXME this add_self_param argument is kind of a hack: Traits have the
         // Self type as an implicit first type parameter, but it can't be
@@ -330,8 +331,8 @@ pub(super) fn substs_from_path_segment(
     if let Some(generic_args) = &segment.args_and_bindings {
         // if args are provided, it should be all of them, but we can't rely on that
         let self_param_correction = if add_self_param { 1 } else { 0 };
-        let param_count = param_count - self_param_correction;
-        for arg in generic_args.args.iter().take(param_count) {
+        let child_len = child_len + self_param_correction;
+        for arg in generic_args.args.iter().take(child_len) {
             match arg {
                 GenericArg::Type(type_ref) => {
                     let ty = Ty::from_hir(db, resolver, type_ref);
@@ -342,10 +343,10 @@ pub(super) fn substs_from_path_segment(
     }
     // add placeholders for args that were not provided
     let supplied_params = substs.len();
-    for _ in supplied_params..parent_param_count + param_count {
+    for _ in supplied_params..total_len {
         substs.push(Ty::Unknown);
     }
-    assert_eq!(substs.len(), parent_param_count + param_count);
+    assert_eq!(substs.len(), total_len);
 
     // handle defaults
     if let Some(def_generic) = def_generic {
@@ -369,11 +370,11 @@ impl TraitRef {
         path: &Path,
         explicit_self_ty: Option<Ty>,
     ) -> Option<Self> {
-        let resolved = match resolver.resolve_path_in_type_ns_fully(db, &path)? {
+        let resolved = match resolver.resolve_path_in_type_ns_fully(db, path.mod_path())? {
             TypeNs::TraitId(tr) => tr,
             _ => return None,
         };
-        let segment = path.segments.last().expect("path should have at least one segment");
+        let segment = path.segments().last().expect("path should have at least one segment");
         Some(TraitRef::from_resolved_path(db, resolver, resolved.into(), segment, explicit_self_ty))
     }
 
@@ -381,7 +382,7 @@ impl TraitRef {
         db: &impl HirDatabase,
         resolver: &Resolver,
         resolved: TraitId,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         explicit_self_ty: Option<Ty>,
     ) -> Self {
         let mut substs = TraitRef::substs_from_path(db, resolver, segment, resolved);
@@ -407,7 +408,7 @@ impl TraitRef {
     fn substs_from_path(
         db: &impl HirDatabase,
         resolver: &Resolver,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         resolved: TraitId,
     ) -> Substs {
         let has_self_param =
@@ -461,12 +462,12 @@ fn assoc_type_bindings_from_type_bound<'a>(
     trait_ref: TraitRef,
 ) -> impl Iterator<Item = GenericPredicate> + 'a {
     let last_segment = match bound {
-        TypeBound::Path(path) => path.segments.last(),
+        TypeBound::Path(path) => path.segments().last(),
         TypeBound::Error => None,
     };
     last_segment
         .into_iter()
-        .flat_map(|segment| segment.args_and_bindings.iter())
+        .flat_map(|segment| segment.args_and_bindings.into_iter())
         .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
         .map(move |(name, type_ref)| {
             let associated_ty =
@@ -532,6 +533,15 @@ pub(crate) fn generic_predicates_for_param_query(
         .collect()
 }
 
+pub(crate) fn generic_predicates_for_param_recover(
+    _db: &impl HirDatabase,
+    _cycle: &[String],
+    _def: &GenericDefId,
+    _param_idx: &u32,
+) -> Arc<[GenericPredicate]> {
+    Arc::new([])
+}
+
 impl TraitEnvironment {
     pub fn lower(db: &impl HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
         let predicates = resolver
@@ -558,12 +568,11 @@ pub(crate) fn generic_predicates_query(
 /// Resolve the default type params from generics
 pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDefId) -> Substs {
     let resolver = def.resolver(db);
-    let generic_params = db.generic_params(def.into());
+    let generic_params = generics(db, def.into());
 
     let defaults = generic_params
-        .params_including_parent()
-        .into_iter()
-        .map(|p| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(db, &resolver, t)))
+        .iter()
+        .map(|(_idx, p)| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(db, &resolver, t)))
         .collect();
 
     Substs(defaults)
@@ -580,7 +589,7 @@ fn fn_sig_for_fn(db: &impl HirDatabase, def: FunctionId) -> FnSig {
 /// Build the declared type of a function. This should not need to look at the
 /// function body.
 fn type_for_fn(db: &impl HirDatabase, def: FunctionId) -> Ty {
-    let generics = db.generic_params(def.into());
+    let generics = generics(db, def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
@@ -630,7 +639,7 @@ fn type_for_struct_constructor(db: &impl HirDatabase, def: StructId) -> Ty {
     if struct_data.variant_data.is_unit() {
         return type_for_adt(db, def.into()); // Unit struct
     }
-    let generics = db.generic_params(def.into());
+    let generics = generics(db, def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
@@ -644,7 +653,7 @@ fn fn_sig_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId
         .iter()
         .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
         .collect::<Vec<_>>();
-    let generics = db.generic_params(def.parent.into());
+    let generics = generics(db, def.parent.into());
     let substs = Substs::identity(&generics);
     let ret = type_for_adt(db, def.parent.into()).subst(&substs);
     FnSig::from_params_and_return(params, ret)
@@ -657,18 +666,18 @@ fn type_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId)
     if var_data.is_unit() {
         return type_for_adt(db, def.parent.into()); // Unit variant
     }
-    let generics = db.generic_params(def.parent.into());
+    let generics = generics(db, def.parent.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(EnumVariantId::from(def).into()), substs)
 }
 
 fn type_for_adt(db: &impl HirDatabase, adt: AdtId) -> Ty {
-    let generics = db.generic_params(adt.into());
+    let generics = generics(db, adt.into());
     Ty::apply(TypeCtor::Adt(adt), Substs::identity(&generics))
 }
 
 fn type_for_type_alias(db: &impl HirDatabase, t: TypeAliasId) -> Ty {
-    let generics = db.generic_params(t.into());
+    let generics = generics(db, t.into());
     let resolver = t.resolver(db);
     let type_ref = &db.type_alias_data(t).type_ref;
     let substs = Substs::identity(&generics);
@@ -687,10 +696,11 @@ impl_froms!(CallableDef: FunctionId, StructId, EnumVariantId);
 impl CallableDef {
     pub fn krate(self, db: &impl HirDatabase) -> CrateId {
         match self {
-            CallableDef::FunctionId(f) => f.lookup(db).module(db).krate,
-            CallableDef::StructId(s) => s.module(db).krate,
-            CallableDef::EnumVariantId(e) => e.parent.module(db).krate,
+            CallableDef::FunctionId(f) => f.lookup(db).module(db),
+            CallableDef::StructId(s) => s.lookup(db).container.module(db),
+            CallableDef::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
         }
+        .krate
     }
 }
 
@@ -733,6 +743,11 @@ pub(crate) fn ty_query(db: &impl HirDatabase, def: TyDefId) -> Ty {
         TyDefId::TypeAliasId(it) => type_for_type_alias(db, it),
     }
 }
+
+pub(crate) fn ty_recover(_db: &impl HirDatabase, _cycle: &[String], _def: &TyDefId) -> Ty {
+    Ty::Unknown
+}
+
 pub(crate) fn value_ty_query(db: &impl HirDatabase, def: ValueTyDefId) -> Ty {
     match def {
         ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
@@ -743,17 +758,24 @@ pub(crate) fn value_ty_query(db: &impl HirDatabase, def: ValueTyDefId) -> Ty {
     }
 }
 
-pub(crate) fn impl_ty_query(db: &impl HirDatabase, impl_id: ImplId) -> ImplTy {
+pub(crate) fn impl_self_ty_query(db: &impl HirDatabase, impl_id: ImplId) -> Ty {
     let impl_data = db.impl_data(impl_id);
     let resolver = impl_id.resolver(db);
-    let self_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
-    match impl_data.target_trait.as_ref() {
-        Some(trait_ref) => {
-            match TraitRef::from_hir(db, &resolver, trait_ref, Some(self_ty.clone())) {
-                Some(it) => ImplTy::TraitRef(it),
-                None => ImplTy::Inherent(self_ty),
-            }
-        }
-        None => ImplTy::Inherent(self_ty),
-    }
+    Ty::from_hir(db, &resolver, &impl_data.target_type)
+}
+
+pub(crate) fn impl_self_ty_recover(
+    _db: &impl HirDatabase,
+    _cycle: &[String],
+    _impl_id: &ImplId,
+) -> Ty {
+    Ty::Unknown
+}
+
+pub(crate) fn impl_trait_query(db: &impl HirDatabase, impl_id: ImplId) -> Option<TraitRef> {
+    let impl_data = db.impl_data(impl_id);
+    let resolver = impl_id.resolver(db);
+    let self_ty = db.impl_self_ty(impl_id);
+    let target_trait = impl_data.target_trait.as_ref()?;
+    TraitRef::from_hir(db, &resolver, target_trait, Some(self_ty.clone()))
 }
diff --git a/crates/ra_hir_ty/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
index 0f754eb9c..fe74acf11 100644
--- a/crates/ra_hir_ty/src/marks.rs
+++ b/crates/ra_hir_ty/src/marks.rs
@@ -6,4 +6,5 @@ test_utils::marks!(
     type_var_resolves_to_int_var
     match_ergonomics_ref
     coerce_merge_fail_fallback
+    insert_vars_for_impl_trait
 );
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index ee1936b0e..888dc3116 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -6,20 +6,21 @@ use std::sync::Arc;
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocItemId, AstItemDef,
-    FunctionId, HasModule, ImplId, TraitId,
+    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocContainerId,
+    AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
 use ra_prof::profile;
 use rustc_hash::FxHashMap;
 
+use super::Substs;
 use crate::{
     autoderef,
     db::HirDatabase,
     primitive::{FloatBitness, Uncertain},
     utils::all_super_traits,
-    Canonical, ImplTy, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor,
+    Canonical, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 /// This is used as a key for indexing impls.
@@ -57,12 +58,13 @@ impl CrateImplBlocks {
 
         let crate_def_map = db.crate_def_map(krate);
         for (_module_id, module_data) in crate_def_map.modules.iter() {
-            for &impl_id in module_data.impls.iter() {
-                match db.impl_ty(impl_id) {
-                    ImplTy::TraitRef(tr) => {
+            for impl_id in module_data.scope.impls() {
+                match db.impl_trait(impl_id) {
+                    Some(tr) => {
                         res.impls_by_trait.entry(tr.trait_).or_default().push(impl_id);
                     }
-                    ImplTy::Inherent(self_ty) => {
+                    None => {
+                        let self_ty = db.impl_self_ty(impl_id);
                         if let Some(self_ty_fp) = TyFingerprint::for_impl(&self_ty) {
                             res.impls.entry(self_ty_fp).or_default().push(impl_id);
                         }
@@ -132,7 +134,7 @@ impl Ty {
                 LangItemTarget::ImplBlockId(it) => Some(it),
                 _ => None,
             })
-            .map(|it| it.module(db).krate)
+            .map(|it| it.lookup(db).container.module(db).krate)
             .collect();
         Some(res)
     }
@@ -175,7 +177,6 @@ pub fn iterate_method_candidates<T>(
     mode: LookupMode,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    let krate = resolver.krate()?;
     match mode {
         LookupMode::MethodCall => {
             // For method calls, rust first does any number of autoderef, and then one
@@ -188,57 +189,159 @@ pub fn iterate_method_candidates<T>(
             // rustc does an autoderef and then autoref again).
             let environment = TraitEnvironment::lower(db, resolver);
             let ty = InEnvironment { value: ty.clone(), environment };
-            for derefed_ty in autoderef::autoderef(db, resolver.krate(), ty) {
-                if let Some(result) =
-                    iterate_inherent_methods(&derefed_ty, db, name, mode, krate, &mut callback)
-                {
-                    return Some(result);
-                }
-                if let Some(result) = iterate_trait_method_candidates(
-                    &derefed_ty,
+            let krate = resolver.krate()?;
+
+            // We have to be careful about the order we're looking at candidates
+            // in here. Consider the case where we're resolving `x.clone()`
+            // where `x: &Vec<_>`. This resolves to the clone method with self
+            // type `Vec<_>`, *not* `&_`. I.e. we need to consider methods where
+            // the receiver type exactly matches before cases where we have to
+            // do autoref. But in the autoderef steps, the `&_` self type comes
+            // up *before* the `Vec<_>` self type.
+            //
+            // On the other hand, we don't want to just pick any by-value method
+            // before any by-autoref method; it's just that we need to consider
+            // the methods by autoderef order of *receiver types*, not *self
+            // types*.
+
+            let deref_chain: Vec<_> = autoderef::autoderef(db, Some(krate), ty.clone()).collect();
+            for i in 0..deref_chain.len() {
+                if let Some(result) = iterate_method_candidates_with_autoref(
+                    &deref_chain[i..],
                     db,
                     resolver,
                     name,
-                    mode,
                     &mut callback,
                 ) {
                     return Some(result);
                 }
             }
+            None
         }
         LookupMode::Path => {
             // No autoderef for path lookups
-            if let Some(result) =
-                iterate_inherent_methods(&ty, db, name, mode, krate.into(), &mut callback)
-            {
-                return Some(result);
-            }
-            if let Some(result) =
-                iterate_trait_method_candidates(&ty, db, resolver, name, mode, &mut callback)
-            {
-                return Some(result);
-            }
+            iterate_method_candidates_for_self_ty(&ty, db, resolver, name, &mut callback)
+        }
+    }
+}
+
+fn iterate_method_candidates_with_autoref<T>(
+    deref_chain: &[Canonical<Ty>],
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &deref_chain[0],
+        &deref_chain[1..],
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    let refed = Canonical {
+        num_vars: deref_chain[0].num_vars,
+        value: Ty::apply_one(TypeCtor::Ref(Mutability::Shared), deref_chain[0].value.clone()),
+    };
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &refed,
+        deref_chain,
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    let ref_muted = Canonical {
+        num_vars: deref_chain[0].num_vars,
+        value: Ty::apply_one(TypeCtor::Ref(Mutability::Mut), deref_chain[0].value.clone()),
+    };
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &ref_muted,
+        deref_chain,
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    None
+}
+
+fn iterate_method_candidates_by_receiver<T>(
+    receiver_ty: &Canonical<Ty>,
+    rest_of_deref_chain: &[Canonical<Ty>],
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    // We're looking for methods with *receiver* type receiver_ty. These could
+    // be found in any of the derefs of receiver_ty, so we have to go through
+    // that.
+    let krate = resolver.krate()?;
+    for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
+        if let Some(result) =
+            iterate_inherent_methods(self_ty, db, name, Some(receiver_ty), krate, &mut callback)
+        {
+            return Some(result);
+        }
+    }
+    for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
+        if let Some(result) = iterate_trait_method_candidates(
+            self_ty,
+            db,
+            resolver,
+            name,
+            Some(receiver_ty),
+            &mut callback,
+        ) {
+            return Some(result);
         }
     }
     None
 }
 
+fn iterate_method_candidates_for_self_ty<T>(
+    self_ty: &Canonical<Ty>,
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    let krate = resolver.krate()?;
+    if let Some(result) = iterate_inherent_methods(self_ty, db, name, None, krate, &mut callback) {
+        return Some(result);
+    }
+    if let Some(result) =
+        iterate_trait_method_candidates(self_ty, db, resolver, name, None, &mut callback)
+    {
+        return Some(result);
+    }
+    None
+}
+
 fn iterate_trait_method_candidates<T>(
-    ty: &Canonical<Ty>,
+    self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     resolver: &Resolver,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
     let krate = resolver.krate()?;
     // FIXME: maybe put the trait_env behind a query (need to figure out good input parameters for that)
     let env = TraitEnvironment::lower(db, resolver);
     // if ty is `impl Trait` or `dyn Trait`, the trait doesn't need to be in scope
-    let inherent_trait = ty.value.inherent_trait().into_iter();
+    let inherent_trait = self_ty.value.inherent_trait().into_iter();
     // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
     let traits_from_env = env
-        .trait_predicates_for_self_ty(&ty.value)
+        .trait_predicates_for_self_ty(&self_ty.value)
         .map(|tr| tr.trait_)
         .flat_map(|t| all_super_traits(db, t));
     let traits =
@@ -251,17 +354,17 @@ fn iterate_trait_method_candidates<T>(
         // iteration
         let mut known_implemented = false;
         for (_name, item) in data.items.iter() {
-            if !is_valid_candidate(db, name, mode, (*item).into()) {
+            if !is_valid_candidate(db, name, receiver_ty, (*item).into(), self_ty) {
                 continue;
             }
             if !known_implemented {
-                let goal = generic_implements_goal(db, env.clone(), t, ty.clone());
+                let goal = generic_implements_goal(db, env.clone(), t, self_ty.clone());
                 if db.trait_solve(krate.into(), goal).is_none() {
                     continue 'traits;
                 }
             }
             known_implemented = true;
-            if let Some(result) = callback(&ty.value, (*item).into()) {
+            if let Some(result) = callback(&self_ty.value, (*item).into()) {
                 return Some(result);
             }
         }
@@ -270,22 +373,22 @@ fn iterate_trait_method_candidates<T>(
 }
 
 fn iterate_inherent_methods<T>(
-    ty: &Canonical<Ty>,
+    self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     krate: CrateId,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    for krate in ty.value.def_crates(db, krate)? {
+    for krate in self_ty.value.def_crates(db, krate)? {
         let impls = db.impls_in_crate(krate);
 
-        for impl_block in impls.lookup_impl_blocks(&ty.value) {
+        for impl_block in impls.lookup_impl_blocks(&self_ty.value) {
             for &item in db.impl_data(impl_block).items.iter() {
-                if !is_valid_candidate(db, name, mode, item) {
+                if !is_valid_candidate(db, name, receiver_ty, item, self_ty) {
                     continue;
                 }
-                if let Some(result) = callback(&ty.value, item.into()) {
+                if let Some(result) = callback(&self_ty.value, item) {
                     return Some(result);
                 }
             }
@@ -297,23 +400,68 @@ fn iterate_inherent_methods<T>(
 fn is_valid_candidate(
     db: &impl HirDatabase,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     item: AssocItemId,
+    self_ty: &Canonical<Ty>,
 ) -> bool {
     match item {
         AssocItemId::FunctionId(m) => {
             let data = db.function_data(m);
-            name.map_or(true, |name| &data.name == name)
-                && (data.has_self_param || mode == LookupMode::Path)
+            if let Some(name) = name {
+                if &data.name != name {
+                    return false;
+                }
+            }
+            if let Some(receiver_ty) = receiver_ty {
+                if !data.has_self_param {
+                    return false;
+                }
+                let transformed_receiver_ty = match transform_receiver_ty(db, m, self_ty) {
+                    Some(ty) => ty,
+                    None => return false,
+                };
+                if transformed_receiver_ty != receiver_ty.value {
+                    return false;
+                }
+            }
+            true
         }
         AssocItemId::ConstId(c) => {
             let data = db.const_data(c);
-            name.map_or(true, |name| data.name.as_ref() == Some(name)) && (mode == LookupMode::Path)
+            name.map_or(true, |name| data.name.as_ref() == Some(name)) && receiver_ty.is_none()
         }
         _ => false,
     }
 }
 
+pub(crate) fn inherent_impl_substs(
+    db: &impl HirDatabase,
+    impl_id: ImplId,
+    self_ty: &Canonical<Ty>,
+) -> Option<Substs> {
+    let vars = Substs::build_for_def(db, impl_id).fill_with_bound_vars(0).build();
+    let self_ty_with_vars = db.impl_self_ty(impl_id).subst(&vars);
+    let self_ty_with_vars = Canonical { num_vars: vars.len(), value: self_ty_with_vars };
+    super::infer::unify(&self_ty_with_vars, self_ty)
+}
+
+fn transform_receiver_ty(
+    db: &impl HirDatabase,
+    function_id: FunctionId,
+    self_ty: &Canonical<Ty>,
+) -> Option<Ty> {
+    let substs = match function_id.lookup(db).container {
+        AssocContainerId::TraitId(_) => Substs::build_for_def(db, function_id)
+            .push(self_ty.value.clone())
+            .fill_with_unknown()
+            .build(),
+        AssocContainerId::ImplId(impl_id) => inherent_impl_substs(db, impl_id, &self_ty)?,
+        AssocContainerId::ContainerId(_) => unreachable!(),
+    };
+    let sig = db.callable_item_signature(function_id.into());
+    Some(sig.params()[0].clone().subst(&substs))
+}
+
 pub fn implements_trait(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 1dc9793f9..1a31b587b 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -74,7 +74,7 @@ impl TestDB {
         for &krate in self.relevant_crates(file_id).iter() {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules.iter() {
-                if data.definition == Some(file_id) {
+                if data.origin.file_id() == Some(file_id) {
                     return ModuleId { krate, local_id };
                 }
             }
@@ -98,7 +98,7 @@ impl TestDB {
                     }
                 }
 
-                for &impl_id in crate_def_map[module_id].impls.iter() {
+                for impl_id in crate_def_map[module_id].scope.impls() {
                     let impl_data = self.impl_data(impl_id);
                     for item in impl_data.items.iter() {
                         if let AssocItemId::FunctionId(f) = item {
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index c8461b447..d447b4571 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -1,21 +1,26 @@
 mod never_type;
 mod coercion;
+mod regression;
+mod simple;
+mod patterns;
+mod traits;
+mod method_resolution;
+mod macros;
 
 use std::fmt::Write;
 use std::sync::Arc;
 
 use hir_def::{
-    body::BodySourceMap, db::DefDatabase, nameres::CrateDefMap, AssocItemId, DefWithBodyId,
-    LocalModuleId, Lookup, ModuleDefId,
+    body::BodySourceMap, child_by_source::ChildBySource, db::DefDatabase, keys,
+    nameres::CrateDefMap, AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
-use hir_expand::Source;
+use hir_expand::InFile;
 use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
 };
-use test_utils::covers;
 
 use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResult};
 
@@ -23,4669 +28,20 @@ use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResu
 // against snapshots of the expected results using insta. Use cargo-insta to
 // update the snapshots.
 
-#[test]
-fn cfg_impl_block() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:foo cfg:test
-use foo::S as T;
-struct S;
-
-#[cfg(test)]
-impl S {
-    fn foo1(&self) -> i32 { 0 }
-}
-
-#[cfg(not(test))]
-impl S {
-    fn foo2(&self) -> i32 { 0 }
-}
-
-fn test() {
-    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
-    t<|>;
-}
-
-//- /foo.rs crate:foo
-struct S;
-
-#[cfg(not(test))]
-impl S {
-    fn foo3(&self) -> i32 { 0 }
-}
-
-#[cfg(test)]
-impl S {
-    fn foo4(&self) -> i32 { 0 }
-}
-"#,
-    );
-    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_await() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-struct IntFuture;
-
-impl Future for IntFuture {
-    type Output = u64;
-}
-
-fn test() {
-    let r = IntFuture;
-    let v = r.await;
-    v<|>;
-}
-
-//- /std.rs crate:std
-#[prelude_import] use future::*;
-mod future {
-    trait Future {
-        type Output;
-    }
-}
-
-"#,
-    );
-    assert_eq!("u64", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_box() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-fn test() {
-    let x = box 1;
-    let t = (x, box x, box &1, box [1]);
-    t<|>;
-}
-
-//- /std.rs crate:std
-#[prelude_import] use prelude::*;
-mod prelude {}
-
-mod boxed {
-    pub struct Box<T: ?Sized> {
-        inner: *mut T,
-    }
-}
-
-"#,
-    );
-    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_adt_self() {
-    let (db, pos) = TestDB::with_position(
-        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 (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-fn test() {
-    let r: Result<i32, u64> = Result::Ok(1);
-    let v = r?;
-    v<|>;
-}
-
-//- /std.rs crate:std
-
-#[prelude_import] use ops::*;
-mod ops {
-    trait Try {
-        type Ok;
-        type Error;
-    }
-}
-
-#[prelude_import] use result::*;
-mod result {
-    enum Result<O, E> {
-        Ok(O),
-        Err(E)
-    }
-
-    impl<O, E> crate::ops::Try for Result<O, E> {
-        type Ok = O;
-        type Error = E;
-    }
-}
-
-"#,
-    );
-    assert_eq!("i32", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_for_loop() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-use std::collections::Vec;
-
-fn test() {
-    let v = Vec::new();
-    v.push("foo");
-    for x in v {
-        x<|>;
-    }
-}
-
-//- /std.rs crate:std
-
-#[prelude_import] use iter::*;
-mod iter {
-    trait IntoIterator {
-        type Item;
-    }
-}
-
-mod collections {
-    struct Vec<T> {}
-    impl<T> Vec<T> {
-        fn new() -> Self { Vec {} }
-        fn push(&mut self, t: T) { }
-    }
-
-    impl<T> crate::iter::IntoIterator for Vec<T> {
-        type Item=T;
-    }
-}
-"#,
-    );
-    assert_eq!("&str", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_while_let() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs
-enum Option<T> { Some(T), None }
-
-fn test() {
-    let foo: Option<f32> = None;
-    while let Option::Some(x) = foo {
-        <|>x
-    }
-}
-
-"#,
-    );
-    assert_eq!("f32", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_basics() {
-    assert_snapshot!(
-        infer(r#"
-fn test(a: u32, b: isize, c: !, d: &str) {
-    a;
-    b;
-    c;
-    d;
-    1usize;
-    1isize;
-    "test";
-    1.0f32;
-}"#),
-        @r###"
-    [9; 10) 'a': u32
-    [17; 18) 'b': isize
-    [27; 28) 'c': !
-    [33; 34) 'd': &str
-    [42; 121) '{     ...f32; }': !
-    [48; 49) 'a': u32
-    [55; 56) 'b': isize
-    [62; 63) 'c': !
-    [69; 70) 'd': &str
-    [76; 82) '1usize': usize
-    [88; 94) '1isize': isize
-    [100; 106) '"test"': &str
-    [112; 118) '1.0f32': f32
-    "###
-    );
-}
-
-#[test]
-fn infer_let() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let a = 1isize;
-    let b: usize = 1;
-    let c = b;
-    let d: u32;
-    let e;
-    let f: i32 = e;
-}
-"#),
-        @r###"
-    [11; 118) '{     ...= e; }': ()
-    [21; 22) 'a': isize
-    [25; 31) '1isize': isize
-    [41; 42) 'b': usize
-    [52; 53) '1': usize
-    [63; 64) 'c': usize
-    [67; 68) 'b': usize
-    [78; 79) 'd': u32
-    [94; 95) 'e': i32
-    [105; 106) 'f': i32
-    [114; 115) 'e': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_paths() {
-    assert_snapshot!(
-        infer(r#"
-fn a() -> u32 { 1 }
-
-mod b {
-    fn c() -> u32 { 1 }
-}
-
-fn test() {
-    a();
-    b::c();
-}
-"#),
-        @r###"
-    [15; 20) '{ 1 }': u32
-    [17; 18) '1': u32
-    [48; 53) '{ 1 }': u32
-    [50; 51) '1': u32
-    [67; 91) '{     ...c(); }': ()
-    [73; 74) 'a': fn a() -> u32
-    [73; 76) 'a()': u32
-    [82; 86) 'b::c': fn c() -> u32
-    [82; 88) 'b::c()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_path_type() {
-    assert_snapshot!(
-        infer(r#"
-struct S;
-
-impl S {
-    fn foo() -> i32 { 1 }
-}
-
-fn test() {
-    S::foo();
-    <S>::foo();
-}
-"#),
-        @r###"
-    [41; 46) '{ 1 }': i32
-    [43; 44) '1': i32
-    [60; 93) '{     ...o(); }': ()
-    [66; 72) 'S::foo': fn foo() -> i32
-    [66; 74) 'S::foo()': i32
-    [80; 88) '<S>::foo': fn foo() -> i32
-    [80; 90) '<S>::foo()': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_slice_method() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "slice"]
-impl<T> [T] {
-    fn foo(&self) -> T {
-        loop {}
-    }
-}
-
-#[lang = "slice_alloc"]
-impl<T> [T] {}
-
-fn test() {
-    <[_]>::foo(b"foo");
-}
-"#),
-        @r###"
-    [45; 49) 'self': &[T]
-    [56; 79) '{     ...     }': T
-    [66; 73) 'loop {}': !
-    [71; 73) '{}': ()
-    [133; 160) '{     ...o"); }': ()
-    [139; 149) '<[_]>::foo': fn foo<u8>(&[T]) -> T
-    [139; 157) '<[_]>:..."foo")': u8
-    [150; 156) 'b"foo"': &[u8]
-    "###
-    );
-}
-
-#[test]
-fn infer_struct() {
-    assert_snapshot!(
-        infer(r#"
-struct A {
-    b: B,
-    c: C,
-}
-struct B;
-struct C(usize);
-
-fn test() {
-    let c = C(1);
-    B;
-    let a: A = A { b: B, c: C(1) };
-    a.b;
-    a.c;
-}
-"#),
-        @r###"
-    [72; 154) '{     ...a.c; }': ()
-    [82; 83) 'c': C
-    [86; 87) 'C': C(usize) -> C
-    [86; 90) 'C(1)': C
-    [88; 89) '1': usize
-    [96; 97) 'B': B
-    [107; 108) 'a': A
-    [114; 133) 'A { b:...C(1) }': A
-    [121; 122) 'B': B
-    [127; 128) 'C': C(usize) -> C
-    [127; 131) 'C(1)': C
-    [129; 130) '1': usize
-    [139; 140) 'a': A
-    [139; 142) 'a.b': B
-    [148; 149) 'a': A
-    [148; 151) 'a.c': C
-    "###
-    );
-}
-
-#[test]
-fn infer_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum E {
-  V1 { field: u32 },
-  V2
-}
-fn test() {
-  E::V1 { field: 1 };
-  E::V2;
-}"#),
-        @r###"
-    [48; 82) '{   E:...:V2; }': ()
-    [52; 70) 'E::V1 ...d: 1 }': E
-    [67; 68) '1': u32
-    [74; 79) 'E::V2': E
-    "###
-    );
-}
-
-#[test]
-fn infer_refs() {
-    assert_snapshot!(
-        infer(r#"
-fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
-    a;
-    *a;
-    &a;
-    &mut a;
-    b;
-    *b;
-    &b;
-    c;
-    *c;
-    d;
-    *d;
-}
-"#),
-        @r###"
-    [9; 10) 'a': &u32
-    [18; 19) 'b': &mut u32
-    [31; 32) 'c': *const u32
-    [46; 47) 'd': *mut u32
-    [59; 150) '{     ... *d; }': ()
-    [65; 66) 'a': &u32
-    [72; 74) '*a': u32
-    [73; 74) 'a': &u32
-    [80; 82) '&a': &&u32
-    [81; 82) 'a': &u32
-    [88; 94) '&mut a': &mut &u32
-    [93; 94) 'a': &u32
-    [100; 101) 'b': &mut u32
-    [107; 109) '*b': u32
-    [108; 109) 'b': &mut u32
-    [115; 117) '&b': &&mut u32
-    [116; 117) 'b': &mut u32
-    [123; 124) 'c': *const u32
-    [130; 132) '*c': u32
-    [131; 132) 'c': *const u32
-    [138; 139) 'd': *mut u32
-    [145; 147) '*d': u32
-    [146; 147) 'd': *mut u32
-    "###
-    );
-}
-
-#[test]
-fn infer_literals() {
-    assert_snapshot!(
-        infer(r##"
-fn test() {
-    5i32;
-    5f32;
-    5f64;
-    "hello";
-    b"bytes";
-    'c';
-    b'b';
-    3.14;
-    5000;
-    false;
-    true;
-    r#"
-        //! doc
-        // non-doc
-        mod foo {}
-        "#;
-    br#"yolo"#;
-}
-"##),
-        @r###"
-    [11; 221) '{     ...o"#; }': ()
-    [17; 21) '5i32': i32
-    [27; 31) '5f32': f32
-    [37; 41) '5f64': f64
-    [47; 54) '"hello"': &str
-    [60; 68) 'b"bytes"': &[u8]
-    [74; 77) ''c'': char
-    [83; 87) 'b'b'': u8
-    [93; 97) '3.14': f64
-    [103; 107) '5000': i32
-    [113; 118) 'false': bool
-    [124; 128) 'true': bool
-    [134; 202) 'r#"   ...    "#': &str
-    [208; 218) 'br#"yolo"#': &[u8]
-    "###
-    );
-}
-
-#[test]
-fn infer_unary_op() {
-    assert_snapshot!(
-        infer(r#"
-enum SomeType {}
-
-fn test(x: SomeType) {
-    let b = false;
-    let c = !b;
-    let a = 100;
-    let d: i128 = -a;
-    let e = -100;
-    let f = !!!true;
-    let g = !42;
-    let h = !10u32;
-    let j = !a;
-    -3.14;
-    !3;
-    -x;
-    !x;
-    -"hello";
-    !"hello";
-}
-"#),
-        @r###"
-    [27; 28) 'x': SomeType
-    [40; 272) '{     ...lo"; }': ()
-    [50; 51) 'b': bool
-    [54; 59) 'false': bool
-    [69; 70) 'c': bool
-    [73; 75) '!b': bool
-    [74; 75) 'b': bool
-    [85; 86) 'a': i128
-    [89; 92) '100': i128
-    [102; 103) 'd': i128
-    [112; 114) '-a': i128
-    [113; 114) 'a': i128
-    [124; 125) 'e': i32
-    [128; 132) '-100': i32
-    [129; 132) '100': i32
-    [142; 143) 'f': bool
-    [146; 153) '!!!true': bool
-    [147; 153) '!!true': bool
-    [148; 153) '!true': bool
-    [149; 153) 'true': bool
-    [163; 164) 'g': i32
-    [167; 170) '!42': i32
-    [168; 170) '42': i32
-    [180; 181) 'h': u32
-    [184; 190) '!10u32': u32
-    [185; 190) '10u32': u32
-    [200; 201) 'j': i128
-    [204; 206) '!a': i128
-    [205; 206) 'a': i128
-    [212; 217) '-3.14': f64
-    [213; 217) '3.14': f64
-    [223; 225) '!3': i32
-    [224; 225) '3': i32
-    [231; 233) '-x': {unknown}
-    [232; 233) 'x': SomeType
-    [239; 241) '!x': {unknown}
-    [240; 241) 'x': SomeType
-    [247; 255) '-"hello"': {unknown}
-    [248; 255) '"hello"': &str
-    [261; 269) '!"hello"': {unknown}
-    [262; 269) '"hello"': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_backwards() {
-    assert_snapshot!(
-        infer(r#"
-fn takes_u32(x: u32) {}
-
-struct S { i32_field: i32 }
-
-fn test() -> &mut &f64 {
-    let a = unknown_function();
-    takes_u32(a);
-    let b = unknown_function();
-    S { i32_field: b };
-    let c = unknown_function();
-    &mut &c
-}
-"#),
-        @r###"
-    [14; 15) 'x': u32
-    [22; 24) '{}': ()
-    [78; 231) '{     ...t &c }': &mut &f64
-    [88; 89) 'a': u32
-    [92; 108) 'unknow...nction': {unknown}
-    [92; 110) 'unknow...tion()': u32
-    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
-    [116; 128) 'takes_u32(a)': ()
-    [126; 127) 'a': u32
-    [138; 139) 'b': i32
-    [142; 158) 'unknow...nction': {unknown}
-    [142; 160) 'unknow...tion()': i32
-    [166; 184) 'S { i3...d: b }': S
-    [181; 182) 'b': i32
-    [194; 195) 'c': f64
-    [198; 214) 'unknow...nction': {unknown}
-    [198; 216) 'unknow...tion()': f64
-    [222; 229) '&mut &c': &mut &f64
-    [227; 229) '&c': &f64
-    [228; 229) 'c': f64
-    "###
-    );
-}
-
-#[test]
-fn infer_self() {
-    assert_snapshot!(
-        infer(r#"
-struct S;
-
-impl S {
-    fn test(&self) {
-        self;
-    }
-    fn test2(self: &Self) {
-        self;
-    }
-    fn test3() -> Self {
-        S {}
-    }
-    fn test4() -> Self {
-        Self {}
-    }
-}
-"#),
-        @r###"
-    [34; 38) 'self': &S
-    [40; 61) '{     ...     }': ()
-    [50; 54) 'self': &S
-    [75; 79) 'self': &S
-    [88; 109) '{     ...     }': ()
-    [98; 102) 'self': &S
-    [133; 153) '{     ...     }': S
-    [143; 147) 'S {}': S
-    [177; 200) '{     ...     }': S
-    [187; 194) 'Self {}': S
-    "###
-    );
-}
-
-#[test]
-fn infer_binary_op() {
-    assert_snapshot!(
-        infer(r#"
-fn f(x: bool) -> i32 {
-    0i32
-}
-
-fn test() -> bool {
-    let x = a && b;
-    let y = true || false;
-    let z = x == y;
-    let t = x != y;
-    let minus_forty: isize = -40isize;
-    let h = minus_forty <= CONST_2;
-    let c = f(z || y) + 5;
-    let d = b;
-    let g = minus_forty ^= i;
-    let ten: usize = 10;
-    let ten_is_eleven = ten == some_num;
-
-    ten < 3
-}
-"#),
-        @r###"
-    [6; 7) 'x': bool
-    [22; 34) '{     0i32 }': i32
-    [28; 32) '0i32': i32
-    [54; 370) '{     ... < 3 }': bool
-    [64; 65) 'x': bool
-    [68; 69) 'a': bool
-    [68; 74) 'a && b': bool
-    [73; 74) 'b': bool
-    [84; 85) 'y': bool
-    [88; 92) 'true': bool
-    [88; 101) 'true || false': bool
-    [96; 101) 'false': bool
-    [111; 112) 'z': bool
-    [115; 116) 'x': bool
-    [115; 121) 'x == y': bool
-    [120; 121) 'y': bool
-    [131; 132) 't': bool
-    [135; 136) 'x': bool
-    [135; 141) 'x != y': bool
-    [140; 141) 'y': bool
-    [151; 162) 'minus_forty': isize
-    [172; 180) '-40isize': isize
-    [173; 180) '40isize': isize
-    [190; 191) 'h': bool
-    [194; 205) 'minus_forty': isize
-    [194; 216) 'minus_...ONST_2': bool
-    [209; 216) 'CONST_2': isize
-    [226; 227) 'c': i32
-    [230; 231) 'f': fn f(bool) -> i32
-    [230; 239) 'f(z || y)': i32
-    [230; 243) 'f(z || y) + 5': i32
-    [232; 233) 'z': bool
-    [232; 238) 'z || y': bool
-    [237; 238) 'y': bool
-    [242; 243) '5': i32
-    [253; 254) 'd': {unknown}
-    [257; 258) 'b': {unknown}
-    [268; 269) 'g': ()
-    [272; 283) 'minus_forty': isize
-    [272; 288) 'minus_...y ^= i': ()
-    [287; 288) 'i': isize
-    [298; 301) 'ten': usize
-    [311; 313) '10': usize
-    [323; 336) 'ten_is_eleven': bool
-    [339; 342) 'ten': usize
-    [339; 354) 'ten == some_num': bool
-    [346; 354) 'some_num': usize
-    [361; 364) 'ten': usize
-    [361; 368) 'ten < 3': bool
-    [367; 368) '3': usize
-    "###
-    );
-}
-
-#[test]
-fn infer_field_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-struct A {
-    b: B,
-}
-struct B;
-
-fn test1(a: A) {
-    let a1 = a;
-    a1.b;
-    let a2 = &a;
-    a2.b;
-    let a3 = &mut a;
-    a3.b;
-    let a4 = &&&&&&&a;
-    a4.b;
-    let a5 = &mut &&mut &&mut a;
-    a5.b;
-}
-
-fn test2(a1: *const A, a2: *mut A) {
-    a1.b;
-    a2.b;
-}
-"#),
-        @r###"
-    [44; 45) 'a': A
-    [50; 213) '{     ...5.b; }': ()
-    [60; 62) 'a1': A
-    [65; 66) 'a': A
-    [72; 74) 'a1': A
-    [72; 76) 'a1.b': B
-    [86; 88) 'a2': &A
-    [91; 93) '&a': &A
-    [92; 93) 'a': A
-    [99; 101) 'a2': &A
-    [99; 103) 'a2.b': B
-    [113; 115) 'a3': &mut A
-    [118; 124) '&mut a': &mut A
-    [123; 124) 'a': A
-    [130; 132) 'a3': &mut A
-    [130; 134) 'a3.b': B
-    [144; 146) 'a4': &&&&&&&A
-    [149; 157) '&&&&&&&a': &&&&&&&A
-    [150; 157) '&&&&&&a': &&&&&&A
-    [151; 157) '&&&&&a': &&&&&A
-    [152; 157) '&&&&a': &&&&A
-    [153; 157) '&&&a': &&&A
-    [154; 157) '&&a': &&A
-    [155; 157) '&a': &A
-    [156; 157) 'a': A
-    [163; 165) 'a4': &&&&&&&A
-    [163; 167) 'a4.b': B
-    [177; 179) 'a5': &mut &&mut &&mut A
-    [182; 200) '&mut &...&mut a': &mut &&mut &&mut A
-    [187; 200) '&&mut &&mut a': &&mut &&mut A
-    [188; 200) '&mut &&mut a': &mut &&mut A
-    [193; 200) '&&mut a': &&mut A
-    [194; 200) '&mut a': &mut A
-    [199; 200) 'a': A
-    [206; 208) 'a5': &mut &&mut &&mut A
-    [206; 210) 'a5.b': B
-    [224; 226) 'a1': *const A
-    [238; 240) 'a2': *mut A
-    [250; 273) '{     ...2.b; }': ()
-    [256; 258) 'a1': *const A
-    [256; 260) 'a1.b': B
-    [266; 268) 'a2': *mut A
-    [266; 270) 'a2.b': B
-    "###
-    );
-}
-
-#[test]
-fn infer_argument_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct A<T>(T);
-
-impl<T> A<T> {
-    fn foo(&self) -> &T {
-        &self.0
-    }
-}
-
-struct B<T>(T);
-
-impl<T> Deref for B<T> {
-    type Target = T;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-fn test() {
-    let t = A::foo(&&B(B(A(42))));
-}
-"#),
-        @r###"
-    [68; 72) 'self': &Self
-    [139; 143) 'self': &A<T>
-    [151; 174) '{     ...     }': &T
-    [161; 168) '&self.0': &T
-    [162; 166) 'self': &A<T>
-    [162; 168) 'self.0': T
-    [255; 259) 'self': &B<T>
-    [278; 301) '{     ...     }': &T
-    [288; 295) '&self.0': &T
-    [289; 293) 'self': &B<T>
-    [289; 295) 'self.0': T
-    [315; 353) '{     ...))); }': ()
-    [325; 326) 't': &i32
-    [329; 335) 'A::foo': fn foo<i32>(&A<T>) -> &T
-    [329; 350) 'A::foo...42))))': &i32
-    [336; 349) '&&B(B(A(42)))': &&B<B<A<i32>>>
-    [337; 349) '&B(B(A(42)))': &B<B<A<i32>>>
-    [338; 339) 'B': B<B<A<i32>>>(T) -> B<T>
-    [338; 349) 'B(B(A(42)))': B<B<A<i32>>>
-    [340; 341) 'B': B<A<i32>>(T) -> B<T>
-    [340; 348) 'B(A(42))': B<A<i32>>
-    [342; 343) 'A': A<i32>(T) -> A<T>
-    [342; 347) 'A(42)': A<i32>
-    [344; 346) '42': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_method_argument_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct A<T>(*mut T);
-
-impl<T> A<T> {
-    fn foo(&self, x: &A<T>) -> &T {
-        &*x.0
-    }
-}
-
-struct B<T>(T);
-
-impl<T> Deref for B<T> {
-    type Target = T;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-fn test(a: A<i32>) {
-    let t = A(0 as *mut _).foo(&&B(B(a)));
-}
-"#),
-        @r###"
-    [68; 72) 'self': &Self
-    [144; 148) 'self': &A<T>
-    [150; 151) 'x': &A<T>
-    [166; 187) '{     ...     }': &T
-    [176; 181) '&*x.0': &T
-    [177; 181) '*x.0': T
-    [178; 179) 'x': &A<T>
-    [178; 181) 'x.0': *mut T
-    [268; 272) 'self': &B<T>
-    [291; 314) '{     ...     }': &T
-    [301; 308) '&self.0': &T
-    [302; 306) 'self': &B<T>
-    [302; 308) 'self.0': T
-    [326; 327) 'a': A<i32>
-    [337; 383) '{     ...))); }': ()
-    [347; 348) 't': &i32
-    [351; 352) 'A': A<i32>(*mut T) -> A<T>
-    [351; 365) 'A(0 as *mut _)': A<i32>
-    [351; 380) 'A(0 as...B(a)))': &i32
-    [353; 354) '0': i32
-    [353; 364) '0 as *mut _': *mut i32
-    [370; 379) '&&B(B(a))': &&B<B<A<i32>>>
-    [371; 379) '&B(B(a))': &B<B<A<i32>>>
-    [372; 373) 'B': B<B<A<i32>>>(T) -> B<T>
-    [372; 379) 'B(B(a))': B<B<A<i32>>>
-    [374; 375) 'B': B<A<i32>>(T) -> B<T>
-    [374; 378) 'B(a)': B<A<i32>>
-    [376; 377) 'a': A<i32>
-    "###
-    );
-}
-
-#[test]
-fn bug_484() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-   let x = if true {};
-}
-"#),
-        @r###"
-    [11; 37) '{    l... {}; }': ()
-    [20; 21) 'x': ()
-    [24; 34) 'if true {}': ()
-    [27; 31) 'true': bool
-    [32; 34) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_in_elseif() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo { field: i32 }
-fn main(foo: Foo) {
-    if true {
-
-    } else if false {
-        foo.field
-    }
-}
-"#),
-        @r###"
-    [35; 38) 'foo': Foo
-    [45; 109) '{     ...   } }': ()
-    [51; 107) 'if tru...     }': ()
-    [54; 58) 'true': bool
-    [59; 67) '{      }': ()
-    [73; 107) 'if fal...     }': ()
-    [76; 81) 'false': bool
-    [82; 107) '{     ...     }': i32
-    [92; 95) 'foo': Foo
-    [92; 101) 'foo.field': i32
-    "###
-    )
-}
-
-#[test]
-fn infer_if_match_with_return() {
-    assert_snapshot!(
-        infer(r#"
-fn foo() {
-    let _x1 = if true {
-        1
-    } else {
-        return;
-    };
-    let _x2 = if true {
-        2
-    } else {
-        return
-    };
-    let _x3 = match true {
-        true => 3,
-        _ => {
-            return;
-        }
-    };
-    let _x4 = match true {
-        true => 4,
-        _ => return
-    };
-}"#),
-        @r###"
-    [10; 323) '{     ...  }; }': ()
-    [20; 23) '_x1': i32
-    [26; 80) 'if tru...     }': i32
-    [29; 33) 'true': bool
-    [34; 51) '{     ...     }': i32
-    [44; 45) '1': i32
-    [57; 80) '{     ...     }': !
-    [67; 73) 'return': !
-    [90; 93) '_x2': i32
-    [96; 149) 'if tru...     }': i32
-    [99; 103) 'true': bool
-    [104; 121) '{     ...     }': i32
-    [114; 115) '2': i32
-    [127; 149) '{     ...     }': !
-    [137; 143) 'return': !
-    [159; 162) '_x3': i32
-    [165; 247) 'match ...     }': i32
-    [171; 175) 'true': bool
-    [186; 190) 'true': bool
-    [194; 195) '3': i32
-    [205; 206) '_': bool
-    [210; 241) '{     ...     }': !
-    [224; 230) 'return': !
-    [257; 260) '_x4': i32
-    [263; 320) 'match ...     }': i32
-    [269; 273) 'true': bool
-    [284; 288) 'true': bool
-    [292; 293) '4': i32
-    [303; 304) '_': bool
-    [308; 314) 'return': !
-    "###
-    )
-}
-
-#[test]
-fn infer_inherent_method() {
-    assert_snapshot!(
-        infer(r#"
-struct A;
-
-impl A {
-    fn foo(self, x: u32) -> i32 {}
-}
-
-mod b {
-    impl super::A {
-        fn bar(&self, x: u64) -> i64 {}
-    }
-}
-
-fn test(a: A) {
-    a.foo(1);
-    (&a).bar(1);
-    a.bar(1);
-}
-"#),
-        @r###"
-    [32; 36) 'self': A
-    [38; 39) 'x': u32
-    [53; 55) '{}': ()
-    [103; 107) 'self': &A
-    [109; 110) 'x': u64
-    [124; 126) '{}': ()
-    [144; 145) 'a': A
-    [150; 198) '{     ...(1); }': ()
-    [156; 157) 'a': A
-    [156; 164) 'a.foo(1)': i32
-    [162; 163) '1': u32
-    [170; 181) '(&a).bar(1)': i64
-    [171; 173) '&a': &A
-    [172; 173) 'a': A
-    [179; 180) '1': u64
-    [187; 188) 'a': A
-    [187; 195) 'a.bar(1)': i64
-    [193; 194) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_inherent_method_str() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "str"]
-impl str {
-    fn foo(&self) -> i32 {}
-}
-
-fn test() {
-    "foo".foo();
-}
-"#),
-        @r###"
-    [40; 44) 'self': &str
-    [53; 55) '{}': ()
-    [69; 89) '{     ...o(); }': ()
-    [75; 80) '"foo"': &str
-    [75; 86) '"foo".foo()': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_tuple() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &str, y: isize) {
-    let a: (u32, &str) = (1, "a");
-    let b = (a, x);
-    let c = (y, x);
-    let d = (c, x);
-    let e = (1, "e");
-    let f = (e, "d");
-}
-"#),
-        @r###"
-    [9; 10) 'x': &str
-    [18; 19) 'y': isize
-    [28; 170) '{     ...d"); }': ()
-    [38; 39) 'a': (u32, &str)
-    [55; 63) '(1, "a")': (u32, &str)
-    [56; 57) '1': u32
-    [59; 62) '"a"': &str
-    [73; 74) 'b': ((u32, &str), &str)
-    [77; 83) '(a, x)': ((u32, &str), &str)
-    [78; 79) 'a': (u32, &str)
-    [81; 82) 'x': &str
-    [93; 94) 'c': (isize, &str)
-    [97; 103) '(y, x)': (isize, &str)
-    [98; 99) 'y': isize
-    [101; 102) 'x': &str
-    [113; 114) 'd': ((isize, &str), &str)
-    [117; 123) '(c, x)': ((isize, &str), &str)
-    [118; 119) 'c': (isize, &str)
-    [121; 122) 'x': &str
-    [133; 134) 'e': (i32, &str)
-    [137; 145) '(1, "e")': (i32, &str)
-    [138; 139) '1': i32
-    [141; 144) '"e"': &str
-    [155; 156) 'f': ((i32, &str), &str)
-    [159; 167) '(e, "d")': ((i32, &str), &str)
-    [160; 161) 'e': (i32, &str)
-    [163; 166) '"d"': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_array() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &str, y: isize) {
-    let a = [x];
-    let b = [a, a];
-    let c = [b, b];
-
-    let d = [y, 1, 2, 3];
-    let d = [1, y, 2, 3];
-    let e = [y];
-    let f = [d, d];
-    let g = [e, e];
-
-    let h = [1, 2];
-    let i = ["a", "b"];
-
-    let b = [a, ["b"]];
-    let x: [u8; 0] = [];
-}
-"#),
-        @r###"
-    [9; 10) 'x': &str
-    [18; 19) 'y': isize
-    [28; 293) '{     ... []; }': ()
-    [38; 39) 'a': [&str;_]
-    [42; 45) '[x]': [&str;_]
-    [43; 44) 'x': &str
-    [55; 56) 'b': [[&str;_];_]
-    [59; 65) '[a, a]': [[&str;_];_]
-    [60; 61) 'a': [&str;_]
-    [63; 64) 'a': [&str;_]
-    [75; 76) 'c': [[[&str;_];_];_]
-    [79; 85) '[b, b]': [[[&str;_];_];_]
-    [80; 81) 'b': [[&str;_];_]
-    [83; 84) 'b': [[&str;_];_]
-    [96; 97) 'd': [isize;_]
-    [100; 112) '[y, 1, 2, 3]': [isize;_]
-    [101; 102) 'y': isize
-    [104; 105) '1': isize
-    [107; 108) '2': isize
-    [110; 111) '3': isize
-    [122; 123) 'd': [isize;_]
-    [126; 138) '[1, y, 2, 3]': [isize;_]
-    [127; 128) '1': isize
-    [130; 131) 'y': isize
-    [133; 134) '2': isize
-    [136; 137) '3': isize
-    [148; 149) 'e': [isize;_]
-    [152; 155) '[y]': [isize;_]
-    [153; 154) 'y': isize
-    [165; 166) 'f': [[isize;_];_]
-    [169; 175) '[d, d]': [[isize;_];_]
-    [170; 171) 'd': [isize;_]
-    [173; 174) 'd': [isize;_]
-    [185; 186) 'g': [[isize;_];_]
-    [189; 195) '[e, e]': [[isize;_];_]
-    [190; 191) 'e': [isize;_]
-    [193; 194) 'e': [isize;_]
-    [206; 207) 'h': [i32;_]
-    [210; 216) '[1, 2]': [i32;_]
-    [211; 212) '1': i32
-    [214; 215) '2': i32
-    [226; 227) 'i': [&str;_]
-    [230; 240) '["a", "b"]': [&str;_]
-    [231; 234) '"a"': &str
-    [236; 239) '"b"': &str
-    [251; 252) 'b': [[&str;_];_]
-    [255; 265) '[a, ["b"]]': [[&str;_];_]
-    [256; 257) 'a': [&str;_]
-    [259; 264) '["b"]': [&str;_]
-    [260; 263) '"b"': &str
-    [275; 276) 'x': [u8;_]
-    [288; 290) '[]': [u8;_]
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &i32) {
-    let y = x;
-    let &z = x;
-    let a = z;
-    let (c, d) = (1, "hello");
-
-    for (e, f) in some_iter {
-        let g = e;
-    }
-
-    if let [val] = opt {
-        let h = val;
-    }
-
-    let lambda = |a: u64, b, c: i32| { a + b; c };
-
-    let ref ref_to_x = x;
-    let mut mut_x = x;
-    let ref mut mut_ref_to_x = x;
-    let k = mut_ref_to_x;
-}
-"#),
-        @r###"
-    [9; 10) 'x': &i32
-    [18; 369) '{     ...o_x; }': ()
-    [28; 29) 'y': &i32
-    [32; 33) 'x': &i32
-    [43; 45) '&z': &i32
-    [44; 45) 'z': i32
-    [48; 49) 'x': &i32
-    [59; 60) 'a': i32
-    [63; 64) 'z': i32
-    [74; 80) '(c, d)': (i32, &str)
-    [75; 76) 'c': i32
-    [78; 79) 'd': &str
-    [83; 95) '(1, "hello")': (i32, &str)
-    [84; 85) '1': i32
-    [87; 94) '"hello"': &str
-    [102; 152) 'for (e...     }': ()
-    [106; 112) '(e, f)': ({unknown}, {unknown})
-    [107; 108) 'e': {unknown}
-    [110; 111) 'f': {unknown}
-    [116; 125) 'some_iter': {unknown}
-    [126; 152) '{     ...     }': ()
-    [140; 141) 'g': {unknown}
-    [144; 145) 'e': {unknown}
-    [158; 205) 'if let...     }': ()
-    [165; 170) '[val]': {unknown}
-    [173; 176) 'opt': {unknown}
-    [177; 205) '{     ...     }': ()
-    [191; 192) 'h': {unknown}
-    [195; 198) 'val': {unknown}
-    [215; 221) 'lambda': |u64, u64, i32| -> i32
-    [224; 256) '|a: u6...b; c }': |u64, u64, i32| -> i32
-    [225; 226) 'a': u64
-    [233; 234) 'b': u64
-    [236; 237) 'c': i32
-    [244; 256) '{ a + b; c }': i32
-    [246; 247) 'a': u64
-    [246; 251) 'a + b': u64
-    [250; 251) 'b': u64
-    [253; 254) 'c': i32
-    [267; 279) 'ref ref_to_x': &&i32
-    [282; 283) 'x': &i32
-    [293; 302) 'mut mut_x': &i32
-    [305; 306) 'x': &i32
-    [316; 336) 'ref mu...f_to_x': &mut &i32
-    [339; 340) 'x': &i32
-    [350; 351) 'k': &mut &i32
-    [354; 366) 'mut_ref_to_x': &mut &i32
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern_match_ergonomics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T>(T);
-
-fn test() {
-    let A(n) = &A(1);
-    let A(n) = &mut A(1);
-}
-"#),
-    @r###"
-    [28; 79) '{     ...(1); }': ()
-    [38; 42) 'A(n)': A<i32>
-    [40; 41) 'n': &i32
-    [45; 50) '&A(1)': &A<i32>
-    [46; 47) 'A': A<i32>(T) -> A<T>
-    [46; 50) 'A(1)': A<i32>
-    [48; 49) '1': i32
-    [60; 64) 'A(n)': A<i32>
-    [62; 63) 'n': &mut i32
-    [67; 76) '&mut A(1)': &mut A<i32>
-    [72; 73) 'A': A<i32>(T) -> A<T>
-    [72; 76) 'A(1)': A<i32>
-    [74; 75) '1': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern_match_ergonomics_ref() {
-    covers!(match_ergonomics_ref);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let v = &(1, &2);
-    let (_, &w) = v;
-}
-"#),
-    @r###"
-    [11; 57) '{     ...= v; }': ()
-    [21; 22) 'v': &(i32, &i32)
-    [25; 33) '&(1, &2)': &(i32, &i32)
-    [26; 33) '(1, &2)': (i32, &i32)
-    [27; 28) '1': i32
-    [30; 32) '&2': &i32
-    [31; 32) '2': i32
-    [43; 50) '(_, &w)': (i32, &i32)
-    [44; 45) '_': i32
-    [47; 49) '&w': &i32
-    [48; 49) 'w': i32
-    [53; 54) 'v': &(i32, &i32)
-    "###
-    );
-}
-
-#[test]
-fn infer_adt_pattern() {
-    assert_snapshot!(
-        infer(r#"
-enum E {
-    A { x: usize },
-    B
-}
-
-struct S(u32, E);
-
-fn test() {
-    let e = E::A { x: 3 };
-
-    let S(y, z) = foo;
-    let E::A { x: new_var } = e;
-
-    match e {
-        E::A { x } => x,
-        E::B if foo => 1,
-        E::B => 10,
-    };
-
-    let ref d @ E::A { .. } = e;
-    d;
-}
-"#),
-        @r###"
-    [68; 289) '{     ...  d; }': ()
-    [78; 79) 'e': E
-    [82; 95) 'E::A { x: 3 }': E
-    [92; 93) '3': usize
-    [106; 113) 'S(y, z)': S
-    [108; 109) 'y': u32
-    [111; 112) 'z': E
-    [116; 119) 'foo': S
-    [129; 148) 'E::A {..._var }': E
-    [139; 146) 'new_var': usize
-    [151; 152) 'e': E
-    [159; 245) 'match ...     }': usize
-    [165; 166) 'e': E
-    [177; 187) 'E::A { x }': E
-    [184; 185) 'x': usize
-    [191; 192) 'x': usize
-    [202; 206) 'E::B': E
-    [210; 213) 'foo': bool
-    [217; 218) '1': usize
-    [228; 232) 'E::B': E
-    [236; 238) '10': usize
-    [256; 275) 'ref d ...{ .. }': &E
-    [264; 275) 'E::A { .. }': E
-    [278; 279) 'e': E
-    [285; 286) 'd': &E
-    "###
-    );
-}
-
-#[test]
-fn infer_struct_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-
-fn test(a1: A<u32>, i: i32) {
-    a1.x;
-    let a2 = A { x: i };
-    a2.x;
-    let a3 = A::<i128> { x: 1 };
-    a3.x;
-}
-"#),
-        @r###"
-    [36; 38) 'a1': A<u32>
-    [48; 49) 'i': i32
-    [56; 147) '{     ...3.x; }': ()
-    [62; 64) 'a1': A<u32>
-    [62; 66) 'a1.x': u32
-    [76; 78) 'a2': A<i32>
-    [81; 91) 'A { x: i }': A<i32>
-    [88; 89) 'i': i32
-    [97; 99) 'a2': A<i32>
-    [97; 101) 'a2.x': i32
-    [111; 113) 'a3': A<i128>
-    [116; 134) 'A::<i1...x: 1 }': A<i128>
-    [131; 132) '1': i128
-    [140; 142) 'a3': A<i128>
-    [140; 144) 'a3.x': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_tuple_struct_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T>(T);
-enum Option<T> { Some(T), None }
-use Option::*;
-
-fn test() {
-    A(42);
-    A(42u128);
-    Some("x");
-    Option::Some("x");
-    None;
-    let x: Option<i64> = None;
-}
-"#),
-        @r###"
-    [76; 184) '{     ...one; }': ()
-    [82; 83) 'A': A<i32>(T) -> A<T>
-    [82; 87) 'A(42)': A<i32>
-    [84; 86) '42': i32
-    [93; 94) 'A': A<u128>(T) -> A<T>
-    [93; 102) 'A(42u128)': A<u128>
-    [95; 101) '42u128': u128
-    [108; 112) 'Some': Some<&str>(T) -> Option<T>
-    [108; 117) 'Some("x")': Option<&str>
-    [113; 116) '"x"': &str
-    [123; 135) 'Option::Some': Some<&str>(T) -> Option<T>
-    [123; 140) 'Option...e("x")': Option<&str>
-    [136; 139) '"x"': &str
-    [146; 150) 'None': Option<{unknown}>
-    [160; 161) 'x': Option<i64>
-    [177; 181) 'None': Option<i64>
-    "###
-    );
-}
-
-#[test]
-fn infer_generics_in_patterns() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-
-enum Option<T> {
-    Some(T),
-    None,
-}
-
-fn test(a1: A<u32>, o: Option<u64>) {
-    let A { x: x2 } = a1;
-    let A::<i64> { x: x3 } = A { x: 1 };
-    match o {
-        Option::Some(t) => t,
-        _ => 1,
-    };
-}
-"#),
-        @r###"
-    [79; 81) 'a1': A<u32>
-    [91; 92) 'o': Option<u64>
-    [107; 244) '{     ...  }; }': ()
-    [117; 128) 'A { x: x2 }': A<u32>
-    [124; 126) 'x2': u32
-    [131; 133) 'a1': A<u32>
-    [143; 161) 'A::<i6...: x3 }': A<i64>
-    [157; 159) 'x3': i64
-    [164; 174) 'A { x: 1 }': A<i64>
-    [171; 172) '1': i64
-    [180; 241) 'match ...     }': u64
-    [186; 187) 'o': Option<u64>
-    [198; 213) 'Option::Some(t)': Option<u64>
-    [211; 212) 't': u64
-    [217; 218) 't': u64
-    [228; 229) '_': Option<u64>
-    [233; 234) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_function_generics() {
-    assert_snapshot!(
-        infer(r#"
-fn id<T>(t: T) -> T { t }
-
-fn test() {
-    id(1u32);
-    id::<i128>(1);
-    let x: u64 = id(1);
-}
-"#),
-        @r###"
-    [10; 11) 't': T
-    [21; 26) '{ t }': T
-    [23; 24) 't': T
-    [38; 98) '{     ...(1); }': ()
-    [44; 46) 'id': fn id<u32>(T) -> T
-    [44; 52) 'id(1u32)': u32
-    [47; 51) '1u32': u32
-    [58; 68) 'id::<i128>': fn id<i128>(T) -> T
-    [58; 71) 'id::<i128>(1)': i128
-    [69; 70) '1': i128
-    [81; 82) 'x': u64
-    [90; 92) 'id': fn id<u64>(T) -> T
-    [90; 95) 'id(1)': u64
-    [93; 94) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_impl_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T1, T2> {
-    x: T1,
-    y: T2,
-}
-impl<Y, X> A<X, Y> {
-    fn x(self) -> X {
-        self.x
-    }
-    fn y(self) -> Y {
-        self.y
-    }
-    fn z<T>(self, t: T) -> (X, Y, T) {
-        (self.x, self.y, t)
-    }
-}
-
-fn test() -> i128 {
-    let a = A { x: 1u64, y: 1i64 };
-    a.x();
-    a.y();
-    a.z(1i128);
-    a.z::<u128>(1);
-}
-"#),
-        @r###"
-    [74; 78) 'self': A<X, Y>
-    [85; 107) '{     ...     }': X
-    [95; 99) 'self': A<X, Y>
-    [95; 101) 'self.x': X
-    [117; 121) 'self': A<X, Y>
-    [128; 150) '{     ...     }': Y
-    [138; 142) 'self': A<X, Y>
-    [138; 144) 'self.y': Y
-    [163; 167) 'self': A<X, Y>
-    [169; 170) 't': T
-    [188; 223) '{     ...     }': (X, Y, T)
-    [198; 217) '(self.....y, t)': (X, Y, T)
-    [199; 203) 'self': A<X, Y>
-    [199; 205) 'self.x': X
-    [207; 211) 'self': A<X, Y>
-    [207; 213) 'self.y': Y
-    [215; 216) 't': T
-    [245; 342) '{     ...(1); }': ()
-    [255; 256) 'a': A<u64, i64>
-    [259; 281) 'A { x:...1i64 }': A<u64, i64>
-    [266; 270) '1u64': u64
-    [275; 279) '1i64': i64
-    [287; 288) 'a': A<u64, i64>
-    [287; 292) 'a.x()': u64
-    [298; 299) 'a': A<u64, i64>
-    [298; 303) 'a.y()': i64
-    [309; 310) 'a': A<u64, i64>
-    [309; 319) 'a.z(1i128)': (u64, i64, i128)
-    [313; 318) '1i128': i128
-    [325; 326) 'a': A<u64, i64>
-    [325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
-    [337; 338) '1': u128
-    "###
-    );
-}
-
-#[test]
-fn infer_impl_generics_with_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-enum Option<T> {
-    Some(T),
-    None,
-}
-impl<T> Option<T> {
-    fn as_ref(&self) -> Option<&T> {}
-}
-fn test(o: Option<u32>) {
-    (&o).as_ref();
-    o.as_ref();
-}
-"#),
-        @r###"
-    [78; 82) 'self': &Option<T>
-    [98; 100) '{}': ()
-    [111; 112) 'o': Option<u32>
-    [127; 165) '{     ...f(); }': ()
-    [133; 146) '(&o).as_ref()': Option<&u32>
-    [134; 136) '&o': &Option<u32>
-    [135; 136) 'o': Option<u32>
-    [152; 153) 'o': Option<u32>
-    [152; 162) 'o.as_ref()': Option<&u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_generic_chain() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-impl<T2> A<T2> {
-    fn x(self) -> T2 {
-        self.x
-    }
-}
-fn id<T>(t: T) -> T { t }
-
-fn test() -> i128 {
-     let x = 1;
-     let y = id(x);
-     let a = A { x: id(y) };
-     let z = id(a.x);
-     let b = A { x: z };
-     b.x()
-}
-"#),
-        @r###"
-    [53; 57) 'self': A<T2>
-    [65; 87) '{     ...     }': T2
-    [75; 79) 'self': A<T2>
-    [75; 81) 'self.x': T2
-    [99; 100) 't': T
-    [110; 115) '{ t }': T
-    [112; 113) 't': T
-    [135; 261) '{     ....x() }': i128
-    [146; 147) 'x': i128
-    [150; 151) '1': i128
-    [162; 163) 'y': i128
-    [166; 168) 'id': fn id<i128>(T) -> T
-    [166; 171) 'id(x)': i128
-    [169; 170) 'x': i128
-    [182; 183) 'a': A<i128>
-    [186; 200) 'A { x: id(y) }': A<i128>
-    [193; 195) 'id': fn id<i128>(T) -> T
-    [193; 198) 'id(y)': i128
-    [196; 197) 'y': i128
-    [211; 212) 'z': i128
-    [215; 217) 'id': fn id<i128>(T) -> T
-    [215; 222) 'id(a.x)': i128
-    [218; 219) 'a': A<i128>
-    [218; 221) 'a.x': i128
-    [233; 234) 'b': A<i128>
-    [237; 247) 'A { x: z }': A<i128>
-    [244; 245) 'z': i128
-    [254; 255) 'b': A<i128>
-    [254; 259) 'b.x()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_const() {
-    assert_snapshot!(
-        infer(r#"
-struct Struct;
-
-impl Struct {
-    const FOO: u32 = 1;
-}
-
-enum Enum {}
-
-impl Enum {
-    const BAR: u32 = 2;
-}
-
-trait Trait {
-    const ID: u32;
-}
-
-struct TraitTest;
-
-impl Trait for TraitTest {
-    const ID: u32 = 5;
-}
-
-fn test() {
-    let x = Struct::FOO;
-    let y = Enum::BAR;
-    let z = TraitTest::ID;
-}
-"#),
-        @r###"
-    [52; 53) '1': u32
-    [105; 106) '2': u32
-    [213; 214) '5': u32
-    [229; 307) '{     ...:ID; }': ()
-    [239; 240) 'x': u32
-    [243; 254) 'Struct::FOO': u32
-    [264; 265) 'y': u32
-    [268; 277) 'Enum::BAR': u32
-    [287; 288) 'z': u32
-    [291; 304) 'TraitTest::ID': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_struct() {
-    assert_snapshot!(
-        infer(r#"
-struct A { x: u32 }
-
-impl A {
-    fn new() -> A {
-        A { x: 0 }
-    }
-}
-fn test() {
-    let a = A::new();
-    a.x;
-}
-"#),
-        @r###"
-    [49; 75) '{     ...     }': A
-    [59; 69) 'A { x: 0 }': A
-    [66; 67) '0': u32
-    [88; 122) '{     ...a.x; }': ()
-    [98; 99) 'a': A
-    [102; 108) 'A::new': fn new() -> A
-    [102; 110) 'A::new()': A
-    [116; 117) 'a': A
-    [116; 119) 'a.x': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum A { B, C }
-
-impl A {
-    pub fn b() -> A {
-        A::B
-    }
-    pub fn c() -> A {
-        A::C
-    }
-}
-fn test() {
-    let a = A::b();
-    a;
-    let c = A::c();
-    c;
-}
-"#),
-        @r###"
-    [47; 67) '{     ...     }': A
-    [57; 61) 'A::B': A
-    [88; 108) '{     ...     }': A
-    [98; 102) 'A::C': A
-    [121; 178) '{     ...  c; }': ()
-    [131; 132) 'a': A
-    [135; 139) 'A::b': fn b() -> A
-    [135; 141) 'A::b()': A
-    [147; 148) 'a': A
-    [158; 159) 'c': A
-    [162; 166) 'A::c': fn c() -> A
-    [162; 168) 'A::c()': A
-    [174; 175) 'c': A
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_with_modules() {
-    assert_snapshot!(
-        infer(r#"
-mod a {
-    struct A;
-    impl A { pub fn thing() -> A { A {} }}
-}
-
-mod b {
-    struct B;
-    impl B { pub fn thing() -> u32 { 99 }}
-
-    mod c {
-        struct C;
-        impl C { pub fn thing() -> C { C {} }}
-    }
-}
-use b::c;
-
-fn test() {
-    let x = a::A::thing();
-    let y = b::B::thing();
-    let z = c::C::thing();
-}
-"#),
-        @r###"
-    [56; 64) '{ A {} }': A
-    [58; 62) 'A {}': A
-    [126; 132) '{ 99 }': u32
-    [128; 130) '99': u32
-    [202; 210) '{ C {} }': C
-    [204; 208) 'C {}': C
-    [241; 325) '{     ...g(); }': ()
-    [251; 252) 'x': A
-    [255; 266) 'a::A::thing': fn thing() -> A
-    [255; 268) 'a::A::thing()': A
-    [278; 279) 'y': u32
-    [282; 293) 'b::B::thing': fn thing() -> u32
-    [282; 295) 'b::B::thing()': u32
-    [305; 306) 'z': C
-    [309; 320) 'c::C::thing': fn thing() -> C
-    [309; 322) 'c::C::thing()': C
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make(val: T) -> Gen<T> {
-        Gen { val }
-    }
-}
-
-fn test() {
-    let a = Gen::make(0u32);
-}
-"#),
-        @r###"
-    [64; 67) 'val': T
-    [82; 109) '{     ...     }': Gen<T>
-    [92; 103) 'Gen { val }': Gen<T>
-    [98; 101) 'val': T
-    [123; 155) '{     ...32); }': ()
-    [133; 134) 'a': Gen<u32>
-    [137; 146) 'Gen::make': fn make<u32>(T) -> Gen<T>
-    [137; 152) 'Gen::make(0u32)': Gen<u32>
-    [147; 151) '0u32': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_param() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T=u32> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-}
-"#),
-        @r###"
-    [80; 104) '{     ...     }': Gen<T>
-    [90; 98) 'loop { }': !
-    [95; 98) '{ }': ()
-    [118; 146) '{     ...e(); }': ()
-    [128; 129) 'a': Gen<u32>
-    [132; 141) 'Gen::make': fn make<u32>() -> Gen<T>
-    [132; 143) 'Gen::make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_tuple_param() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct Gen<T=()> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-    a.val<|>;
-}
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
-fn infer_associated_method_generics_without_args() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::<u32>::make();
-}
-"#),
-        @r###"
-    [76; 100) '{     ...     }': Gen<T>
-    [86; 94) 'loop { }': !
-    [91; 94) '{ }': ()
-    [114; 149) '{     ...e(); }': ()
-    [124; 125) 'a': Gen<u32>
-    [128; 144) 'Gen::<...::make': fn make<u32>() -> Gen<T>
-    [128; 146) 'Gen::<...make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_2_type_params_without_args() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T, U> {
-    val: T,
-    val2: U,
-}
-
-impl<T> Gen<u32, T> {
-    pub fn make() -> Gen<u32,T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::<u32, u64>::make();
-}
-"#),
-        @r###"
-    [102; 126) '{     ...     }': Gen<u32, T>
-    [112; 120) 'loop { }': !
-    [117; 120) '{ }': ()
-    [140; 180) '{     ...e(); }': ()
-    [150; 151) 'a': Gen<u32, u64>
-    [154; 175) 'Gen::<...::make': fn make<u64>() -> Gen<u32, T>
-    [154; 177) 'Gen::<...make()': Gen<u32, u64>
-    "###
-    );
-}
-
-#[test]
-fn infer_type_alias() {
-    assert_snapshot!(
-        infer(r#"
-struct A<X, Y> { x: X, y: Y }
-type Foo = A<u32, i128>;
-type Bar<T> = A<T, u128>;
-type Baz<U, V> = A<V, U>;
-fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
-    x.x;
-    x.y;
-    y.x;
-    y.y;
-    z.x;
-    z.y;
-}
-"#),
-        @r###"
-    [116; 117) 'x': A<u32, i128>
-    [124; 125) 'y': A<&str, u128>
-    [138; 139) 'z': A<u8, i8>
-    [154; 211) '{     ...z.y; }': ()
-    [160; 161) 'x': A<u32, i128>
-    [160; 163) 'x.x': u32
-    [169; 170) 'x': A<u32, i128>
-    [169; 172) 'x.y': i128
-    [178; 179) 'y': A<&str, u128>
-    [178; 181) 'y.x': &str
-    [187; 188) 'y': A<&str, u128>
-    [187; 190) 'y.y': u128
-    [196; 197) 'z': A<u8, i8>
-    [196; 199) 'z.x': u8
-    [205; 206) 'z': A<u8, i8>
-    [205; 208) 'z.y': i8
-    "###
-    )
-}
-
-#[test]
-#[should_panic] // we currently can't handle this
-fn recursive_type_alias() {
-    assert_snapshot!(
-        infer(r#"
-struct A<X> {}
-type Foo = Foo;
-type Bar = A<Bar>;
-fn test(x: Foo) {}
-"#),
-        @""
-    )
-}
-
-#[test]
-fn no_panic_on_field_of_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum X {}
-
-fn test(x: X) {
-    x.some_field;
-}
-"#),
-        @r###"
-    [20; 21) 'x': X
-    [26; 47) '{     ...eld; }': ()
-    [32; 33) 'x': X
-    [32; 44) 'x.some_field': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn bug_585() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    X {};
-    match x {
-        A::B {} => (),
-        A::Y() => (),
-    }
-}
-"#),
-        @r###"
-    [11; 89) '{     ...   } }': ()
-    [17; 21) 'X {}': {unknown}
-    [27; 87) 'match ...     }': ()
-    [33; 34) 'x': {unknown}
-    [45; 52) 'A::B {}': {unknown}
-    [56; 58) '()': ()
-    [68; 74) 'A::Y()': {unknown}
-    [78; 80) '()': ()
-    "###
-    );
-}
-
-#[test]
-fn bug_651() {
-    assert_snapshot!(
-        infer(r#"
-fn quux() {
-    let y = 92;
-    1 + y;
-}
-"#),
-        @r###"
-    [11; 41) '{     ...+ y; }': ()
-    [21; 22) 'y': i32
-    [25; 27) '92': i32
-    [33; 34) '1': i32
-    [33; 38) '1 + y': i32
-    [37; 38) 'y': i32
-    "###
-    );
-}
-
-#[test]
-fn recursive_vars() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let y = unknown;
-    [y, &y];
-}
-"#),
-        @r###"
-    [11; 48) '{     ...&y]; }': ()
-    [21; 22) 'y': &{unknown}
-    [25; 32) 'unknown': &{unknown}
-    [38; 45) '[y, &y]': [&&{unknown};_]
-    [39; 40) 'y': &{unknown}
-    [42; 44) '&y': &&{unknown}
-    [43; 44) 'y': &{unknown}
-    "###
-    );
-}
-
-#[test]
-fn recursive_vars_2() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let x = unknown;
-    let y = unknown;
-    [(x, y), (&y, &x)];
-}
-"#),
-        @r###"
-    [11; 80) '{     ...x)]; }': ()
-    [21; 22) 'x': &&{unknown}
-    [25; 32) 'unknown': &&{unknown}
-    [42; 43) 'y': &&{unknown}
-    [46; 53) 'unknown': &&{unknown}
-    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
-    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
-    [61; 62) 'x': &&{unknown}
-    [64; 65) 'y': &&{unknown}
-    [68; 76) '(&y, &x)': (&&&{unknown}, &&&{unknown})
-    [69; 71) '&y': &&&{unknown}
-    [70; 71) 'y': &&{unknown}
-    [73; 75) '&x': &&&{unknown}
-    [74; 75) 'x': &&{unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_type_param() {
-    assert_snapshot!(
-        infer(r#"
-fn id<T>(x: T) -> T {
-    x
-}
-
-fn clone<T>(x: &T) -> T {
-    *x
-}
-
-fn test() {
-    let y = 10u32;
-    id(y);
-    let x: bool = clone(z);
-    id::<i128>(1);
-}
-"#),
-        @r###"
-    [10; 11) 'x': T
-    [21; 30) '{     x }': T
-    [27; 28) 'x': T
-    [44; 45) 'x': &T
-    [56; 66) '{     *x }': T
-    [62; 64) '*x': T
-    [63; 64) 'x': &T
-    [78; 158) '{     ...(1); }': ()
-    [88; 89) 'y': u32
-    [92; 97) '10u32': u32
-    [103; 105) 'id': fn id<u32>(T) -> T
-    [103; 108) 'id(y)': u32
-    [106; 107) 'y': u32
-    [118; 119) 'x': bool
-    [128; 133) 'clone': fn clone<bool>(&T) -> T
-    [128; 136) 'clone(z)': bool
-    [134; 135) 'z': &bool
-    [142; 152) 'id::<i128>': fn id<i128>(T) -> T
-    [142; 155) 'id::<i128>(1)': i128
-    [153; 154) '1': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_1() {
-    // caused stack overflow, taken from std
-    assert_snapshot!(
-        infer(r#"
-enum Maybe<T> {
-    Real(T),
-    Fake,
-}
-
-fn write() {
-    match something_unknown {
-        Maybe::Real(ref mut something) => (),
-    }
-}
-"#),
-        @r###"
-    [54; 139) '{     ...   } }': ()
-    [60; 137) 'match ...     }': ()
-    [66; 83) 'someth...nknown': Maybe<{unknown}>
-    [94; 124) 'Maybe:...thing)': Maybe<{unknown}>
-    [106; 123) 'ref mu...ething': &mut {unknown}
-    [128; 130) '()': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_2() {
-    covers!(type_var_resolves_to_int_var);
-    // caused "equating two type variables, ...", taken from std
-    assert_snapshot!(
-        infer(r#"
-fn test_line_buffer() {
-    &[0, b'\n', 1, b'\n'];
-}
-"#),
-        @r###"
-    [23; 53) '{     ...n']; }': ()
-    [29; 50) '&[0, b...b'\n']': &[u8;_]
-    [30; 50) '[0, b'...b'\n']': [u8;_]
-    [31; 32) '0': u8
-    [34; 39) 'b'\n'': u8
-    [41; 42) '1': u8
-    [44; 49) 'b'\n'': u8
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_3() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-pub fn compute() {
-    match nope!() {
-        SizeSkeleton::Pointer { non_zero: true, tail } => {}
-    }
-}
-"#),
-        @r###"
-    [18; 108) '{     ...   } }': ()
-    [24; 106) 'match ...     }': ()
-    [30; 37) 'nope!()': {unknown}
-    [48; 94) 'SizeSk...tail }': {unknown}
-    [82; 86) 'true': {unknown}
-    [88; 92) 'tail': {unknown}
-    [98; 100) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_4() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-pub fn primitive_type() {
-    match *self {
-        BorrowedRef { type_: Primitive(p), ..} => {},
-    }
-}
-"#),
-        @r###"
-    [25; 106) '{     ...   } }': ()
-    [31; 104) 'match ...     }': ()
-    [37; 42) '*self': {unknown}
-    [38; 42) 'self': {unknown}
-    [53; 91) 'Borrow...), ..}': {unknown}
-    [74; 86) 'Primitive(p)': {unknown}
-    [84; 85) 'p': {unknown}
-    [95; 97) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_5() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-fn extra_compiler_flags() {
-    for content in doesnt_matter {
-        let name = if doesnt_matter {
-            first
-        } else {
-            &content
-        };
-
-        let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
-            name
-        } else {
-            content
-        };
-    }
-}
-"#),
-        @r###"
-    [27; 323) '{     ...   } }': ()
-    [33; 321) 'for co...     }': ()
-    [37; 44) 'content': &{unknown}
-    [48; 61) 'doesnt_matter': {unknown}
-    [62; 321) '{     ...     }': ()
-    [76; 80) 'name': &&{unknown}
-    [83; 167) 'if doe...     }': &&{unknown}
-    [86; 99) 'doesnt_matter': bool
-    [100; 129) '{     ...     }': &&{unknown}
-    [114; 119) 'first': &&{unknown}
-    [135; 167) '{     ...     }': &&{unknown}
-    [149; 157) '&content': &&{unknown}
-    [150; 157) 'content': &{unknown}
-    [182; 189) 'content': &{unknown}
-    [192; 314) 'if ICE...     }': &{unknown}
-    [195; 232) 'ICE_RE..._VALUE': {unknown}
-    [195; 248) 'ICE_RE...&name)': bool
-    [242; 247) '&name': &&&{unknown}
-    [243; 247) 'name': &&{unknown}
-    [249; 277) '{     ...     }': &&{unknown}
-    [263; 267) 'name': &&{unknown}
-    [283; 314) '{     ...     }': &{unknown}
-    [297; 304) 'content': &{unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_nested_generics_crash() {
-    // another crash found typechecking rustc
-    assert_snapshot!(
-        infer(r#"
-struct Canonical<V> {
-    value: V,
-}
-struct QueryResponse<V> {
-    value: V,
-}
-fn test<R>(query_response: Canonical<QueryResponse<R>>) {
-    &query_response.value;
-}
-"#),
-        @r###"
-    [92; 106) 'query_response': Canonical<QueryResponse<R>>
-    [137; 167) '{     ...lue; }': ()
-    [143; 164) '&query....value': &QueryResponse<R>
-    [144; 158) 'query_response': Canonical<QueryResponse<R>>
-    [144; 164) 'query_....value': QueryResponse<R>
-    "###
-    );
-}
-
-#[test]
-fn bug_1030() {
-    assert_snapshot!(infer(r#"
-struct HashSet<T, H>;
-struct FxHasher;
-type FxHashSet<T> = HashSet<T, FxHasher>;
-
-impl<T, H> HashSet<T, H> {
-    fn default() -> HashSet<T, H> {}
-}
-
-pub fn main_loop() {
-    FxHashSet::default();
-}
-"#),
-    @r###"
-    [144; 146) '{}': ()
-    [169; 198) '{     ...t(); }': ()
-    [175; 193) 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<T, H>
-    [175; 195) 'FxHash...ault()': HashSet<{unknown}, FxHasher>
-    "###
-    );
-}
-
-#[test]
-fn cross_crate_associated_method_call() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:other_crate
-fn test() {
-    let x = other_crate::foo::S::thing();
-    x<|>;
-}
-
-//- /lib.rs crate:other_crate
-mod foo {
-    struct S;
-    impl S {
-        fn thing() -> i128 {}
-    }
-}
-"#,
-    );
-    assert_eq!("i128", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_const() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo;
-impl Foo { const ASSOC_CONST: u32 = 0; }
-const GLOBAL_CONST: u32 = 101;
-fn test() {
-    const LOCAL_CONST: u32 = 99;
-    let x = LOCAL_CONST;
-    let z = GLOBAL_CONST;
-    let id = Foo::ASSOC_CONST;
-}
-"#),
-        @r###"
-    [49; 50) '0': u32
-    [80; 83) '101': u32
-    [95; 213) '{     ...NST; }': ()
-    [138; 139) 'x': {unknown}
-    [142; 153) 'LOCAL_CONST': {unknown}
-    [163; 164) 'z': u32
-    [167; 179) 'GLOBAL_CONST': u32
-    [189; 191) 'id': u32
-    [194; 210) 'Foo::A..._CONST': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_static() {
-    assert_snapshot!(
-        infer(r#"
-static GLOBAL_STATIC: u32 = 101;
-static mut GLOBAL_STATIC_MUT: u32 = 101;
-fn test() {
-    static LOCAL_STATIC: u32 = 99;
-    static mut LOCAL_STATIC_MUT: u32 = 99;
-    let x = LOCAL_STATIC;
-    let y = LOCAL_STATIC_MUT;
-    let z = GLOBAL_STATIC;
-    let w = GLOBAL_STATIC_MUT;
-}
-"#),
-        @r###"
-    [29; 32) '101': u32
-    [70; 73) '101': u32
-    [85; 280) '{     ...MUT; }': ()
-    [173; 174) 'x': {unknown}
-    [177; 189) 'LOCAL_STATIC': {unknown}
-    [199; 200) 'y': {unknown}
-    [203; 219) 'LOCAL_...IC_MUT': {unknown}
-    [229; 230) 'z': u32
-    [233; 246) 'GLOBAL_STATIC': u32
-    [256; 257) 'w': u32
-    [260; 277) 'GLOBAL...IC_MUT': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_simple() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait1 {
-    fn method(&self) -> u32;
-}
-struct S1;
-impl Trait1 for S1 {}
-trait Trait2 {
-    fn method(&self) -> i128;
-}
-struct S2;
-impl Trait2 for S2 {}
-fn test() {
-    S1.method(); // -> u32
-    S2.method(); // -> i128
-}
-"#),
-        @r###"
-    [31; 35) 'self': &Self
-    [110; 114) 'self': &Self
-    [170; 228) '{     ...i128 }': ()
-    [176; 178) 'S1': S1
-    [176; 187) 'S1.method()': u32
-    [203; 205) 'S2': S2
-    [203; 214) 'S2.method()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_scoped() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-struct S;
-mod foo {
-    pub trait Trait1 {
-        fn method(&self) -> u32;
-    }
-    impl Trait1 for super::S {}
-}
-mod bar {
-    pub trait Trait2 {
-        fn method(&self) -> i128;
-    }
-    impl Trait2 for super::S {}
-}
-
-mod foo_test {
-    use super::S;
-    use super::foo::Trait1;
-    fn test() {
-        S.method(); // -> u32
-    }
-}
-
-mod bar_test {
-    use super::S;
-    use super::bar::Trait2;
-    fn test() {
-        S.method(); // -> i128
-    }
-}
-"#),
-        @r###"
-    [63; 67) 'self': &Self
-    [169; 173) 'self': &Self
-    [300; 337) '{     ...     }': ()
-    [310; 311) 'S': S
-    [310; 320) 'S.method()': u32
-    [416; 454) '{     ...     }': ()
-    [426; 427) 'S': S
-    [426; 436) 'S.method()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_1() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-struct S;
-impl Trait<u32> for S {}
-fn test() {
-    S.method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [92; 111) '{     ...d(); }': ()
-    [98; 99) 'S': S
-    [98; 108) 'S.method()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_more_params() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T1, T2, T3> {
-    fn method1(&self) -> (T1, T2, T3);
-    fn method2(&self) -> (T3, T2, T1);
-}
-struct S1;
-impl Trait<u8, u16, u32> for S1 {}
-struct S2;
-impl<T> Trait<i8, i16, T> for S2 {}
-fn test() {
-    S1.method1(); // u8, u16, u32
-    S1.method2(); // u32, u16, u8
-    S2.method1(); // i8, i16, {unknown}
-    S2.method2(); // {unknown}, i16, i8
-}
-"#),
-        @r###"
-    [43; 47) 'self': &Self
-    [82; 86) 'self': &Self
-    [210; 361) '{     ..., i8 }': ()
-    [216; 218) 'S1': S1
-    [216; 228) 'S1.method1()': (u8, u16, u32)
-    [250; 252) 'S1': S1
-    [250; 262) 'S1.method2()': (u32, u16, u8)
-    [284; 286) 'S2': S2
-    [284; 296) 'S2.method1()': (i8, i16, {unknown})
-    [324; 326) 'S2': S2
-    [324; 336) 'S2.method2()': ({unknown}, i16, i8)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_2() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn test() {
-    S(1u32).method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [102; 127) '{     ...d(); }': ()
-    [108; 109) 'S': S<u32>(T) -> S<T>
-    [108; 115) 'S(1u32)': S<u32>
-    [108; 124) 'S(1u32...thod()': u32
-    [110; 114) '1u32': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method() {
-    assert_snapshot!(
-        infer(r#"
-trait Default {
-    fn default() -> Self;
-}
-struct S;
-impl Default for S {}
-fn test() {
-    let s1: S = Default::default();
-    let s2 = S::default();
-    let s3 = <S as Default>::default();
-}
-"#),
-        @r###"
-    [87; 193) '{     ...t(); }': ()
-    [97; 99) 's1': S
-    [105; 121) 'Defaul...efault': fn default<S>() -> Self
-    [105; 123) 'Defaul...ault()': S
-    [133; 135) 's2': S
-    [138; 148) 'S::default': fn default<S>() -> Self
-    [138; 150) 'S::default()': S
-    [160; 162) 's3': S
-    [165; 188) '<S as ...efault': fn default<S>() -> Self
-    [165; 190) '<S as ...ault()': S
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> T;
-}
-struct S;
-impl Trait<u32> for S {}
-struct G<T>;
-impl<T> Trait<T> for G<T> {}
-fn test() {
-    let a = S::make();
-    let b = G::<u64>::make();
-    let c: f64 = G::make();
-}
-"#),
-        @r###"
-    [127; 211) '{     ...e(); }': ()
-    [137; 138) 'a': u32
-    [141; 148) 'S::make': fn make<S, u32>() -> T
-    [141; 150) 'S::make()': u32
-    [160; 161) 'b': u64
-    [164; 178) 'G::<u64>::make': fn make<G<u64>, u64>() -> T
-    [164; 180) 'G::<u6...make()': u64
-    [190; 191) 'c': f64
-    [199; 206) 'G::make': fn make<G<f64>, f64>() -> T
-    [199; 208) 'G::make()': f64
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make<U>() -> (T, U);
-}
-struct S;
-impl Trait<u32> for S {}
-struct G<T>;
-impl<T> Trait<T> for G<T> {}
-fn test() {
-    let a = S::make::<i64>();
-    let b: (_, i64) = S::make();
-    let c = G::<u32>::make::<i64>();
-    let d: (u32, _) = G::make::<i64>();
-    let e: (u32, i64) = G::make();
-}
-"#),
-        @r###"
-    [135; 313) '{     ...e(); }': ()
-    [145; 146) 'a': (u32, i64)
-    [149; 163) 'S::make::<i64>': fn make<S, u32, i64>() -> (T, U)
-    [149; 165) 'S::mak...i64>()': (u32, i64)
-    [175; 176) 'b': (u32, i64)
-    [189; 196) 'S::make': fn make<S, u32, i64>() -> (T, U)
-    [189; 198) 'S::make()': (u32, i64)
-    [208; 209) 'c': (u32, i64)
-    [212; 233) 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
-    [212; 235) 'G::<u3...i64>()': (u32, i64)
-    [245; 246) 'd': (u32, i64)
-    [259; 273) 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
-    [259; 275) 'G::mak...i64>()': (u32, i64)
-    [285; 286) 'e': (u32, i64)
-    [301; 308) 'G::make': fn make<G<u32>, u32, i64>() -> (T, U)
-    [301; 310) 'G::make()': (u32, i64)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_3() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> (Self, T);
-}
-struct S<T>;
-impl Trait<i64> for S<i32> {}
-fn test() {
-    let a = S::make();
-}
-"#),
-        @r###"
-    [101; 127) '{     ...e(); }': ()
-    [111; 112) 'a': (S<i32>, i64)
-    [115; 122) 'S::make': fn make<S<i32>, i64>() -> (Self, T)
-    [115; 124) 'S::make()': (S<i32>, i64)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_4() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> (Self, T);
-}
-struct S<T>;
-impl Trait<i64> for S<u64> {}
-impl Trait<i32> for S<u32> {}
-fn test() {
-    let a: (S<u64>, _) = S::make();
-    let b: (_, i32) = S::make();
-}
-"#),
-        @r###"
-    [131; 203) '{     ...e(); }': ()
-    [141; 142) 'a': (S<u64>, i64)
-    [158; 165) 'S::make': fn make<S<u64>, i64>() -> (Self, T)
-    [158; 167) 'S::make()': (S<u64>, i64)
-    [177; 178) 'b': (S<u32>, i32)
-    [191; 198) 'S::make': fn make<S<u32>, i32>() -> (Self, T)
-    [191; 200) 'S::make()': (S<u32>, i32)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_5() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make<U>() -> (Self, T, U);
-}
-struct S<T>;
-impl Trait<i64> for S<u64> {}
-fn test() {
-    let a = <S as Trait<i64>>::make::<u8>();
-    let b: (S<u64>, _, _) = Trait::<i64>::make::<u8>();
-}
-"#),
-        @r###"
-    [107; 211) '{     ...>(); }': ()
-    [117; 118) 'a': (S<u64>, i64, u8)
-    [121; 150) '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
-    [121; 152) '<S as ...<u8>()': (S<u64>, i64, u8)
-    [162; 163) 'b': (S<u64>, i64, u8)
-    [182; 206) 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
-    [182; 208) 'Trait:...<u8>()': (S<u64>, i64, u8)
-    "###
-    );
-}
-
-#[test]
-fn infer_from_bound_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn foo<T: Trait<u32>>(t: T) {}
-fn test() {
-    let s = S(unknown);
-    foo(s);
-}
-"#),
-        @r###"
-    [86; 87) 't': T
-    [92; 94) '{}': ()
-    [105; 144) '{     ...(s); }': ()
-    [115; 116) 's': S<u32>
-    [119; 120) 'S': S<u32>(T) -> S<T>
-    [119; 129) 'S(unknown)': S<u32>
-    [121; 128) 'unknown': u32
-    [135; 138) 'foo': fn foo<S<u32>>(T) -> ()
-    [135; 141) 'foo(s)': ()
-    [139; 140) 's': S<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_from_bound_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn foo<U, T: Trait<U>>(t: T) -> U {}
-fn test() {
-    let s = S(unknown);
-    let x: u32 = foo(s);
-}
-"#),
-        @r###"
-    [87; 88) 't': T
-    [98; 100) '{}': ()
-    [111; 163) '{     ...(s); }': ()
-    [121; 122) 's': S<u32>
-    [125; 126) 'S': S<u32>(T) -> S<T>
-    [125; 135) 'S(unknown)': S<u32>
-    [127; 134) 'unknown': u32
-    [145; 146) 'x': u32
-    [154; 157) 'foo': fn foo<u32, S<u32>>(T) -> U
-    [154; 160) 'foo(s)': u32
-    [158; 159) 's': S<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_call_trait_method_on_generic_param_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    fn method(&self) -> u32;
-}
-fn test<T: Trait>(t: T) {
-    t.method();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [64; 65) 't': T
-    [70; 89) '{     ...d(); }': ()
-    [76; 77) 't': T
-    [76; 86) 't.method()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_call_trait_method_on_generic_param_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-fn test<U, T: Trait<U>>(t: T) {
-    t.method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [71; 72) 't': T
-    [77; 96) '{     ...d(); }': ()
-    [83; 84) 't': T
-    [83; 93) 't.method()': [missing name]
-    "###
-    );
-}
-
-#[test]
-fn infer_with_multiple_trait_impls() {
-    assert_snapshot!(
-        infer(r#"
-trait Into<T> {
-    fn into(self) -> T;
-}
-struct S;
-impl Into<u32> for S {}
-impl Into<u64> for S {}
-fn test() {
-    let x: u32 = S.into();
-    let y: u64 = S.into();
-    let z = Into::<u64>::into(S);
-}
-"#),
-        @r###"
-    [29; 33) 'self': Self
-    [111; 202) '{     ...(S); }': ()
-    [121; 122) 'x': u32
-    [130; 131) 'S': S
-    [130; 138) 'S.into()': u32
-    [148; 149) 'y': u64
-    [157; 158) 'S': S
-    [157; 165) 'S.into()': u64
-    [175; 176) 'z': u64
-    [179; 196) 'Into::...::into': fn into<S, u64>(Self) -> T
-    [179; 199) 'Into::...nto(S)': u64
-    [197; 198) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn infer_project_associated_type() {
-    // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-struct S;
-impl Iterable for S { type Item = u32; }
-fn test<T: Iterable>() {
-    let x: <S as Iterable>::Item = 1;
-    let y: <T as Iterable>::Item = no_matter;
-    let z: T::Item = no_matter;
-    let a: <T>::Item = no_matter;
-}
-"#),
-        @r###"
-    [108; 261) '{     ...ter; }': ()
-    [118; 119) 'x': u32
-    [145; 146) '1': u32
-    [156; 157) 'y': {unknown}
-    [183; 192) 'no_matter': {unknown}
-    [202; 203) 'z': {unknown}
-    [215; 224) 'no_matter': {unknown}
-    [234; 235) 'a': {unknown}
-    [249; 258) 'no_matter': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_return_associated_type() {
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-struct S;
-impl Iterable for S { type Item = u32; }
-fn foo1<T: Iterable>(t: T) -> T::Item {}
-fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
-fn foo3<T: Iterable>(t: T) -> <T>::Item {}
-fn test() {
-    let x = foo1(S);
-    let y = foo2(S);
-    let z = foo3(S);
-}
-"#),
-        @r###"
-    [106; 107) 't': T
-    [123; 125) '{}': ()
-    [147; 148) 't': T
-    [178; 180) '{}': ()
-    [202; 203) 't': T
-    [221; 223) '{}': ()
-    [234; 300) '{     ...(S); }': ()
-    [244; 245) 'x': u32
-    [248; 252) 'foo1': fn foo1<S>(T) -> <T as Iterable>::Item
-    [248; 255) 'foo1(S)': u32
-    [253; 254) 'S': S
-    [265; 266) 'y': u32
-    [269; 273) 'foo2': fn foo2<S>(T) -> <T as Iterable>::Item
-    [269; 276) 'foo2(S)': u32
-    [274; 275) 'S': S
-    [286; 287) 'z': u32
-    [290; 294) 'foo3': fn foo3<S>(T) -> <T as Iterable>::Item
-    [290; 297) 'foo3(S)': u32
-    [295; 296) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_type_bound() {
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-fn test<T: Iterable<Item=u32>>() {
-    let y: T::Item = unknown;
-}
-"#),
-        @r###"
-    [67; 100) '{     ...own; }': ()
-    [77; 78) 'y': {unknown}
-    [90; 97) 'unknown': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_const_body() {
-    assert_snapshot!(
-        infer(r#"
-const A: u32 = 1 + 1;
-static B: u64 = { let x = 1; x };
-"#),
-        @r###"
-    [16; 17) '1': u32
-    [16; 21) '1 + 1': u32
-    [20; 21) '1': u32
-    [39; 55) '{ let ...1; x }': u64
-    [45; 46) 'x': u64
-    [49; 50) '1': u64
-    [52; 53) 'x': u64
-    "###
-    );
-}
-
-#[test]
-fn tuple_struct_fields() {
-    assert_snapshot!(
-        infer(r#"
-struct S(i32, u64);
-fn test() -> u64 {
-    let a = S(4, 6);
-    let b = a.0;
-    a.1
-}
-"#),
-        @r###"
-    [38; 87) '{     ... a.1 }': u64
-    [48; 49) 'a': S
-    [52; 53) 'S': S(i32, u64) -> S
-    [52; 59) 'S(4, 6)': S
-    [54; 55) '4': i32
-    [57; 58) '6': u64
-    [69; 70) 'b': i32
-    [73; 74) 'a': S
-    [73; 76) 'a.0': i32
-    [82; 83) 'a': S
-    [82; 85) 'a.1': u64
-    "###
-    );
-}
-
-#[test]
-fn tuple_struct_with_fn() {
-    assert_snapshot!(
-        infer(r#"
-struct S(fn(u32) -> u64);
-fn test() -> u64 {
-    let a = S(|i| 2*i);
-    let b = a.0(4);
-    a.0(2)
-}
-"#),
-        @r###"
-    [44; 102) '{     ...0(2) }': u64
-    [54; 55) 'a': S
-    [58; 59) 'S': S(fn(u32) -> u64) -> S
-    [58; 68) 'S(|i| 2*i)': S
-    [60; 67) '|i| 2*i': |i32| -> i32
-    [61; 62) 'i': i32
-    [64; 65) '2': i32
-    [64; 67) '2*i': i32
-    [66; 67) 'i': i32
-    [78; 79) 'b': u64
-    [82; 83) 'a': S
-    [82; 85) 'a.0': fn(u32) -> u64
-    [82; 88) 'a.0(4)': u64
-    [86; 87) '4': u32
-    [94; 95) 'a': S
-    [94; 97) 'a.0': fn(u32) -> u64
-    [94; 100) 'a.0(2)': u64
-    [98; 99) '2': u32
-    "###
-    );
-}
-
-#[test]
-fn indexing_arrays() {
-    assert_snapshot!(
-        infer("fn main() { &mut [9][2]; }"),
-        @r###"
-    [10; 26) '{ &mut...[2]; }': ()
-    [12; 23) '&mut [9][2]': &mut {unknown}
-    [17; 20) '[9]': [i32;_]
-    [17; 23) '[9][2]': {unknown}
-    [18; 19) '9': i32
-    [21; 22) '2': i32
-    "###
-    )
-}
-
-#[test]
-fn infer_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo(Vec<i32>);
-
-macro_rules! foo {
-    ($($item:expr),*) => {
-            {
-                Foo(vec![$($item,)*])
-            }
-    };
-}
-
-fn main() {
-    let x = foo!(1,2);
-}
-"#),
-        @r###"
-    ![0; 17) '{Foo(v...,2,])}': Foo
-    ![1; 4) 'Foo': Foo({unknown}) -> Foo
-    ![1; 16) 'Foo(vec![1,2,])': Foo
-    ![5; 15) 'vec![1,2,]': {unknown}
-    [156; 182) '{     ...,2); }': ()
-    [166; 167) 'x': Foo
-    "###
-    );
-}
-
-#[test]
-fn infer_legacy_textual_scoped_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo(Vec<i32>);
-
-#[macro_use]
-mod m {
-    macro_rules! foo {
-        ($($item:expr),*) => {
-            {
-                Foo(vec![$($item,)*])
-            }
-        };
-    }
-}
-
-fn main() {
-    let x = foo!(1,2);
-    let y = crate::foo!(1,2);
-}
-"#),
-        @r###"
-    ![0; 17) '{Foo(v...,2,])}': Foo
-    ![1; 4) 'Foo': Foo({unknown}) -> Foo
-    ![1; 16) 'Foo(vec![1,2,])': Foo
-    ![5; 15) 'vec![1,2,]': {unknown}
-    [195; 251) '{     ...,2); }': ()
-    [205; 206) 'x': Foo
-    [228; 229) 'y': {unknown}
-    [232; 248) 'crate:...!(1,2)': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_path_qualified_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-#[macro_export]
-macro_rules! foo {
-    () => { 42i32 }
-}
-
-mod m {
-    pub use super::foo as bar;
-}
-
-fn main() {
-    let x = crate::foo!();
-    let y = m::bar!();
-}
-"#),
-        @r###"
-    ![0; 5) '42i32': i32
-    ![0; 5) '42i32': i32
-    [111; 164) '{     ...!(); }': ()
-    [121; 122) 'x': i32
-    [148; 149) 'y': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_type_value_macro_having_same_name() {
-    assert_snapshot!(
-        infer(r#"
-#[macro_export]
-macro_rules! foo {
-    () => {
-        mod foo {
-            pub use super::foo;
-        }
-    };
-    ($x:tt) => {
-        $x
-    };
-}
-
-foo!();
-
-fn foo() {
-    let foo = foo::foo!(42i32);
-}
-"#),
-        @r###"
-    ![0; 5) '42i32': i32
-    [171; 206) '{     ...32); }': ()
-    [181; 184) 'foo': i32
-    "###
-    );
-}
-
-#[test]
-fn processes_impls_generated_by_macros() {
-    let t = type_at(
-        r#"
-//- /main.rs
-macro_rules! m {
-    ($ident:ident) => (impl Trait for $ident {})
-}
-trait Trait { fn foo(self) -> u128 {} }
-struct S;
-m!(S);
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn infer_macro_with_dollar_crate_is_correct_in_expr() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:foo
-fn test() {
-    let x = (foo::foo!(1), foo::foo!(2));
-    x<|>;
-}
-
-//- /lib.rs crate:foo
-#[macro_export]
-macro_rules! foo {
-    (1) => { $crate::bar!() };
-    (2) => { 1 + $crate::baz() };
-}
-
-#[macro_export]
-macro_rules! bar {
-    () => { 42 }
-}
-
-pub fn baz() -> usize { 31usize }
-"#,
-    );
-    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
-}
-
-#[ignore]
-#[test]
-fn method_resolution_trait_before_autoref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(&self) -> i8 { 0 } }
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[ignore]
-#[test]
-fn method_resolution_by_value_before_autoref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone { fn clone(&self) -> Self; }
-struct S;
-impl Clone for S {}
-impl Clone for &S {}
-fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
-"#,
-    );
-    assert_eq!(t, "(S, S, &S)");
-}
-
-#[test]
-fn method_resolution_trait_before_autoderef() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(self) -> i8 { 0 } }
-impl Trait for &S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_impl_before_trait() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(self) -> i8 { 0 } }
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "i8");
-}
-
-#[test]
-fn method_resolution_trait_autoderef() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_trait_from_prelude() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:other_crate
-struct S;
-impl Clone for S {}
-
-fn test() {
-    S.clone()<|>;
-}
-
-//- /lib.rs crate:other_crate
-#[prelude_import] use foo::*;
-
-mod foo {
-    trait Clone {
-        fn clone(&self) -> Self;
-    }
-}
-"#,
-    );
-    assert_eq!("S", type_at_pos(&db, pos));
-}
-
-#[test]
-fn method_resolution_where_clause_for_unknown_trait() {
-    // The blanket impl shouldn't apply because we can't even resolve UnknownTrait
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T> Trait for T where T: UnknownTrait {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_not_met() {
-    // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T> Trait for T where T: Clone {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    // This is also to make sure that we don't resolve to the foo method just
-    // because that's the only method named foo we can find, which would make
-    // the below tests not work
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_inline_not_met() {
-    // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T: Clone> Trait for T {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_where_clause_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Into<T> { fn into(self) -> T; }
-trait From<T> { fn from(other: T) -> Self; }
-struct S1;
-struct S2;
-impl From<S2> for S1 {}
-impl<T, U> Into<U> for T where U: From<T> {}
-fn test() { S2.into()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_inline() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Into<T> { fn into(self) -> T; }
-trait From<T> { fn from(other: T) -> Self; }
-struct S1;
-struct S2;
-impl From<S2> for S1 {}
-impl<T, U: From<T>> Into<U> for T {}
-fn test() { S2.into()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_encountering_fn_type() {
-    type_at(
-        r#"
-//- /main.rs
-fn foo() {}
-trait FnOnce { fn call(self); }
-fn test() { foo.call()<|>; }
-"#,
-    );
-}
-
-#[test]
-fn method_resolution_slow() {
-    // this can get quite slow if we set the solver size limit too high
-    let t = type_at(
-        r#"
-//- /main.rs
-trait SendX {}
-
-struct S1; impl SendX for S1 {}
-struct S2; impl SendX for S2 {}
-struct U1;
-
-trait Trait { fn method(self); }
-
-struct X1<A, B> {}
-impl<A, B> SendX for X1<A, B> where A: SendX, B: SendX {}
-
-struct S<B, C> {}
-
-trait FnX {}
-
-impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
-
-fn test() { (S {}).method()<|>; }
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
-fn shadowing_primitive() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct i32;
-struct Foo;
-
-impl i32 { fn foo(&self) -> Foo { Foo } }
-
-fn main() {
-    let x: i32 = i32;
-    x.foo()<|>;
-}"#,
-    );
-    assert_eq!(t, "Foo");
-}
-
-#[test]
-fn deref_trait() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-impl S {
-    fn foo(&self) -> u128 {}
-}
-
-fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
-"#,
-    );
-    assert_eq!(t, "(S, u128)");
-}
-
-#[test]
-fn deref_trait_with_inference_var() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-fn new_arc<T>() -> Arc<T> {}
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-fn foo(a: Arc<S>) {}
-
-fn test() {
-    let a = new_arc();
-    let b = (*a)<|>;
-    foo(a);
-}
-"#,
-    );
-    assert_eq!(t, "S");
-}
-
-#[test]
-fn deref_trait_infinite_recursion() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct S;
-
-impl Deref for S {
-    type Target = S;
-}
-
-fn test(s: S) {
-    s.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn deref_trait_with_question_mark_size() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-impl S {
-    fn foo(&self) -> u128 {}
-}
-
-fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
-"#,
-    );
-    assert_eq!(t, "(S, u128)");
-}
-
-#[test]
-fn obligation_from_function_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<u32> for S {}
-
-fn foo<T: Trait<U>, U>(t: T) -> U {}
-
-fn test(s: S) {
-    foo(s)<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn obligation_from_method_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<isize> for S {}
-
-struct O;
-impl O {
-    fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
-}
-
-fn test() {
-    O.foo(S)<|>;
-}
-"#,
-    );
-    assert_eq!(t, "isize");
-}
-
-#[test]
-fn obligation_from_self_method_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<i64> for S {}
-
-impl S {
-    fn foo<U>(&self) -> U where Self: Trait<U> {}
-}
-
-fn test() {
-    S.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "i64");
-}
-
-#[test]
-fn obligation_from_impl_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<&str> for S {}
-
-struct O<T>;
-impl<U, T: Trait<U>> O<T> {
-    fn foo(&self) -> U {}
-}
-
-fn test(o: O<S>) {
-    o.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "&str");
-}
-
-#[test]
-fn generic_param_env_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test<T: Clone>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn generic_param_env_1_not_met() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test<T>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn generic_param_env_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S {}
-fn test<T: Trait>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn generic_param_env_2_not_met() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S {}
-fn test<T>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn generic_param_env_deref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-}
-trait Trait {}
-impl<T> Deref for T where T: Trait {
-    type Target = i128;
-}
-fn test<T: Trait>(t: T) { (*t)<|>; }
-"#,
-    );
-    assert_eq!(t, "i128");
-}
-
-#[test]
-fn associated_type_placeholder() {
-    let t = type_at(
-        r#"
-//- /main.rs
-pub trait ApplyL {
-    type Out;
-}
-
-pub struct RefMutL<T>;
-
-impl<T> ApplyL for RefMutL<T> {
-    type Out = <T as ApplyL>::Out;
-}
-
-fn test<T: ApplyL>() {
-    let y: <RefMutL<T> as ApplyL>::Out = no_matter;
-    y<|>;
-}
-"#,
-    );
-    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
-    // FIXME: fix type parameter names going missing when going through Chalk
-    assert_eq!(t, "ApplyL::Out<[missing name]>");
-}
-
-#[test]
-fn associated_type_placeholder_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-pub trait ApplyL {
-    type Out;
-}
-fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
-
-fn test<T: ApplyL>(t: T) {
-    let y = foo(t);
-    y<|>;
-}
-"#,
-    );
-    // FIXME here Chalk doesn't normalize the type to a placeholder. I think we
-    // need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
-    // to the trait env ourselves here; probably Chalk can't do this by itself.
-    // assert_eq!(t, "ApplyL::Out<[missing name]>");
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn impl_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn foo(&self) -> T;
-    fn foo2(&self) -> i64;
-}
-fn bar() -> impl Trait<u64> {}
-
-fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-    x.foo2();
-    y.foo2();
-    z.foo2();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [55; 59) 'self': &Self
-    [99; 101) '{}': ()
-    [111; 112) 'x': impl Trait<u64>
-    [131; 132) 'y': &impl Trait<u64>
-    [152; 269) '{     ...2(); }': ()
-    [158; 159) 'x': impl Trait<u64>
-    [165; 166) 'y': &impl Trait<u64>
-    [176; 177) 'z': impl Trait<u64>
-    [180; 183) 'bar': fn bar() -> impl Trait<u64>
-    [180; 185) 'bar()': impl Trait<u64>
-    [191; 192) 'x': impl Trait<u64>
-    [191; 198) 'x.foo()': u64
-    [204; 205) 'y': &impl Trait<u64>
-    [204; 211) 'y.foo()': u64
-    [217; 218) 'z': impl Trait<u64>
-    [217; 224) 'z.foo()': u64
-    [230; 231) 'x': impl Trait<u64>
-    [230; 238) 'x.foo2()': i64
-    [244; 245) 'y': &impl Trait<u64>
-    [244; 252) 'y.foo2()': i64
-    [258; 259) 'z': impl Trait<u64>
-    [258; 266) 'z.foo2()': i64
-    "###
-    );
-}
-
-#[test]
-fn dyn_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn foo(&self) -> T;
-    fn foo2(&self) -> i64;
-}
-fn bar() -> dyn Trait<u64> {}
-
-fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-    x.foo2();
-    y.foo2();
-    z.foo2();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [55; 59) 'self': &Self
-    [98; 100) '{}': ()
-    [110; 111) 'x': dyn Trait<u64>
-    [129; 130) 'y': &dyn Trait<u64>
-    [149; 266) '{     ...2(); }': ()
-    [155; 156) 'x': dyn Trait<u64>
-    [162; 163) 'y': &dyn Trait<u64>
-    [173; 174) 'z': dyn Trait<u64>
-    [177; 180) 'bar': fn bar() -> dyn Trait<u64>
-    [177; 182) 'bar()': dyn Trait<u64>
-    [188; 189) 'x': dyn Trait<u64>
-    [188; 195) 'x.foo()': u64
-    [201; 202) 'y': &dyn Trait<u64>
-    [201; 208) 'y.foo()': u64
-    [214; 215) 'z': dyn Trait<u64>
-    [214; 221) 'z.foo()': u64
-    [227; 228) 'x': dyn Trait<u64>
-    [227; 235) 'x.foo2()': i64
-    [241; 242) 'y': &dyn Trait<u64>
-    [241; 249) 'y.foo2()': i64
-    [255; 256) 'z': dyn Trait<u64>
-    [255; 263) 'z.foo2()': i64
-    "###
-    );
-}
-
-#[test]
-fn dyn_trait_bare() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    fn foo(&self) -> u64;
-}
-fn bar() -> Trait {}
-
-fn test(x: Trait, y: &Trait) -> u64 {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-}
-"#),
-        @r###"
-    [27; 31) 'self': &Self
-    [61; 63) '{}': ()
-    [73; 74) 'x': dyn Trait
-    [83; 84) 'y': &dyn Trait
-    [101; 176) '{     ...o(); }': ()
-    [107; 108) 'x': dyn Trait
-    [114; 115) 'y': &dyn Trait
-    [125; 126) 'z': dyn Trait
-    [129; 132) 'bar': fn bar() -> dyn Trait
-    [129; 134) 'bar()': dyn Trait
-    [140; 141) 'x': dyn Trait
-    [140; 147) 'x.foo()': u64
-    [153; 154) 'y': &dyn Trait
-    [153; 160) 'y.foo()': u64
-    [166; 167) 'z': dyn Trait
-    [166; 173) 'z.foo()': u64
-    "###
-    );
-}
-
-#[test]
-fn weird_bounds() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {}
-fn test() {
-    let a: impl Trait + 'lifetime = foo;
-    let b: impl 'lifetime = foo;
-    let b: impl (Trait) = foo;
-    let b: impl ('lifetime) = foo;
-    let d: impl ?Sized = foo;
-    let e: impl Trait + ?Sized = foo;
-}
-"#),
-        @r###"
-    [26; 237) '{     ...foo; }': ()
-    [36; 37) 'a': impl Trait + {error}
-    [64; 67) 'foo': impl Trait + {error}
-    [77; 78) 'b': impl {error}
-    [97; 100) 'foo': impl {error}
-    [110; 111) 'b': impl Trait
-    [128; 131) 'foo': impl Trait
-    [141; 142) 'b': impl {error}
-    [163; 166) 'foo': impl {error}
-    [176; 177) 'd': impl {error}
-    [193; 196) 'foo': impl {error}
-    [206; 207) 'e': impl Trait + {error}
-    [231; 234) 'foo': impl Trait + {error}
-    "###
-    );
-}
-
-#[test]
-fn assoc_type_bindings() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    type Type;
-}
-
-fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
-fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
-fn set<T: Trait<Type = u64>>(t: T) -> T {t}
-
-struct S<T>;
-impl<T> Trait for S<T> { type Type = T; }
-
-fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
-    get(x);
-    get2(x);
-    get(y);
-    get2(y);
-    get(set(S));
-    get2(set(S));
-    get2(S::<str>);
-}
-"#),
-        @r###"
-    [50; 51) 't': T
-    [78; 80) '{}': ()
-    [112; 113) 't': T
-    [123; 125) '{}': ()
-    [155; 156) 't': T
-    [166; 169) '{t}': T
-    [167; 168) 't': T
-    [257; 258) 'x': T
-    [263; 264) 'y': impl Trait<Type = i64>
-    [290; 398) '{     ...r>); }': ()
-    [296; 299) 'get': fn get<T>(T) -> <T as Trait>::Type
-    [296; 302) 'get(x)': {unknown}
-    [300; 301) 'x': T
-    [308; 312) 'get2': fn get2<{unknown}, T>(T) -> U
-    [308; 315) 'get2(x)': {unknown}
-    [313; 314) 'x': T
-    [321; 324) 'get': fn get<impl Trait<Type = i64>>(T) -> <T as Trait>::Type
-    [321; 327) 'get(y)': {unknown}
-    [325; 326) 'y': impl Trait<Type = i64>
-    [333; 337) 'get2': fn get2<{unknown}, impl Trait<Type = i64>>(T) -> U
-    [333; 340) 'get2(y)': {unknown}
-    [338; 339) 'y': impl Trait<Type = i64>
-    [346; 349) 'get': fn get<S<u64>>(T) -> <T as Trait>::Type
-    [346; 357) 'get(set(S))': u64
-    [350; 353) 'set': fn set<S<u64>>(T) -> T
-    [350; 356) 'set(S)': S<u64>
-    [354; 355) 'S': S<u64>
-    [363; 367) 'get2': fn get2<u64, S<u64>>(T) -> U
-    [363; 375) 'get2(set(S))': u64
-    [368; 371) 'set': fn set<S<u64>>(T) -> T
-    [368; 374) 'set(S)': S<u64>
-    [372; 373) 'S': S<u64>
-    [381; 385) 'get2': fn get2<str, S<str>>(T) -> U
-    [381; 395) 'get2(S::<str>)': str
-    [386; 394) 'S::<str>': S<str>
-    "###
-    );
-}
-
-#[test]
-fn impl_trait_assoc_binding_projection_bug() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-pub trait Language {
-    type Kind;
-}
-pub enum RustLanguage {}
-impl Language for RustLanguage {
-    type Kind = SyntaxKind;
-}
-struct SyntaxNode<L> {}
-fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
-
-trait Clone {
-    fn clone(&self) -> Self;
-}
-
-fn api_walkthrough() {
-    for node in foo() {
-        node.clone()<|>;
-    }
-}
-
-//- /std.rs crate:std
-#[prelude_import] use iter::*;
-mod iter {
-    trait IntoIterator {
-        type Item;
-    }
-    trait Iterator {
-        type Item;
-    }
-    impl<T: Iterator> IntoIterator for T {
-        type Item = <T as Iterator>::Item;
-    }
-}
-"#,
-    );
-    assert_eq!("{unknown}", type_at_pos(&db, pos));
-}
-
-#[test]
-fn projection_eq_within_chalk() {
-    // std::env::set_var("CHALK_DEBUG", "1");
-    assert_snapshot!(
-        infer(r#"
-trait Trait1 {
-    type Type;
-}
-trait Trait2<T> {
-    fn foo(self) -> T;
-}
-impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
-
-fn test<T: Trait1<Type = u32>>(x: T) {
-    x.foo();
-}
-"#),
-        @r###"
-    [62; 66) 'self': Self
-    [164; 165) 'x': T
-    [170; 186) '{     ...o(); }': ()
-    [176; 177) 'x': T
-    [176; 183) 'x.foo()': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn where_clause_trait_in_scope_for_method_resolution() {
-    let t = type_at(
-        r#"
-//- /main.rs
-mod foo {
-    trait Trait {
-        fn foo(&self) -> u32 {}
-    }
-}
-
-fn test<T: foo::Trait>(x: T) {
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn super_trait_method_resolution() {
-    assert_snapshot!(
-        infer(r#"
-mod foo {
-    trait SuperTrait {
-        fn foo(&self) -> u32 {}
-    }
-}
-trait Trait1: foo::SuperTrait {}
-trait Trait2 where Self: foo::SuperTrait {}
-
-fn test<T: Trait1, U: Trait2>(x: T, y: U) {
-    x.foo();
-    y.foo();
-}
-"#),
-        @r###"
-    [50; 54) 'self': &Self
-    [63; 65) '{}': ()
-    [182; 183) 'x': T
-    [188; 189) 'y': U
-    [194; 223) '{     ...o(); }': ()
-    [200; 201) 'x': T
-    [200; 207) 'x.foo()': u32
-    [213; 214) 'y': U
-    [213; 220) 'y.foo()': u32
-    "###
-    );
-}
-
-#[test]
-fn super_trait_cycle() {
-    // This just needs to not crash
-    assert_snapshot!(
-        infer(r#"
-trait A: B {}
-trait B: A {}
-
-fn test<T: A>(x: T) {
-    x.foo();
-}
-"#),
-        @r###"
-    [44; 45) 'x': T
-    [50; 66) '{     ...o(); }': ()
-    [56; 57) 'x': T
-    [56; 63) 'x.foo()': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn super_trait_assoc_type_bounds() {
-    assert_snapshot!(
-        infer(r#"
-trait SuperTrait { type Type; }
-trait Trait where Self: SuperTrait {}
-
-fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
-fn set<T: Trait<Type = u64>>(t: T) -> T {t}
-
-struct S<T>;
-impl<T> SuperTrait for S<T> { type Type = T; }
-impl<T> Trait for S<T> {}
-
-fn test() {
-    get2(set(S));
-}
-"#),
-        @r###"
-    [103; 104) 't': T
-    [114; 116) '{}': ()
-    [146; 147) 't': T
-    [157; 160) '{t}': T
-    [158; 159) 't': T
-    [259; 280) '{     ...S)); }': ()
-    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
-    [265; 277) 'get2(set(S))': u64
-    [270; 273) 'set': fn set<S<u64>>(T) -> T
-    [270; 276) 'set(S)': S<u64>
-    [274; 275) 'S': S<u64>
-    "###
-    );
-}
-
-#[test]
-fn fn_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait FnOnce<Args> {
-    type Output;
-
-    fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
-}
-
-fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
-    f.call_once((1, 2));
-}
-"#),
-        @r###"
-    [57; 61) 'self': Self
-    [63; 67) 'args': Args
-    [150; 151) 'f': F
-    [156; 184) '{     ...2)); }': ()
-    [162; 163) 'f': F
-    [162; 181) 'f.call...1, 2))': {unknown}
-    [174; 180) '(1, 2)': (u32, u64)
-    [175; 176) '1': u32
-    [178; 179) '2': u64
-    "###
-    );
-}
-
-#[test]
-fn closure_1() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "fn_once"]
-trait FnOnce<Args> {
-    type Output;
-}
-
-enum Option<T> { Some(T), None }
-impl<T> Option<T> {
-    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
-}
-
-fn test() {
-    let x = Option::Some(1u32);
-    x.map(|v| v + 1);
-    x.map(|_v| 1u64);
-    let y: Option<i64> = x.map(|_v| 1);
-}
-"#),
-        @r###"
-    [148; 152) 'self': Option<T>
-    [154; 155) 'f': F
-    [173; 175) '{}': ()
-    [189; 308) '{     ... 1); }': ()
-    [199; 200) 'x': Option<u32>
-    [203; 215) 'Option::Some': Some<u32>(T) -> Option<T>
-    [203; 221) 'Option...(1u32)': Option<u32>
-    [216; 220) '1u32': u32
-    [227; 228) 'x': Option<u32>
-    [227; 243) 'x.map(...v + 1)': Option<u32>
-    [233; 242) '|v| v + 1': |u32| -> u32
-    [234; 235) 'v': u32
-    [237; 238) 'v': u32
-    [237; 242) 'v + 1': u32
-    [241; 242) '1': u32
-    [249; 250) 'x': Option<u32>
-    [249; 265) 'x.map(... 1u64)': Option<u64>
-    [255; 264) '|_v| 1u64': |u32| -> u64
-    [256; 258) '_v': u32
-    [260; 264) '1u64': u64
-    [275; 276) 'y': Option<i64>
-    [292; 293) 'x': Option<u32>
-    [292; 305) 'x.map(|_v| 1)': Option<i64>
-    [298; 304) '|_v| 1': |u32| -> i64
-    [299; 301) '_v': u32
-    [303; 304) '1': i64
-    "###
-    );
-}
-
-#[test]
-fn closure_2() {
-    assert_snapshot!(
-        infer(r#"
-trait FnOnce<Args> {
-    type Output;
-}
-
-fn test<F: FnOnce(u32) -> u64>(f: F) {
-    f(1);
-    let g = |v| v + 1;
-    g(1u64);
-    let h = |v| 1u128 + v;
-}
-"#),
-        @r###"
-    [73; 74) 'f': F
-    [79; 155) '{     ...+ v; }': ()
-    [85; 86) 'f': F
-    [85; 89) 'f(1)': {unknown}
-    [87; 88) '1': i32
-    [99; 100) 'g': |u64| -> i32
-    [103; 112) '|v| v + 1': |u64| -> i32
-    [104; 105) 'v': u64
-    [107; 108) 'v': u64
-    [107; 112) 'v + 1': i32
-    [111; 112) '1': i32
-    [118; 119) 'g': |u64| -> i32
-    [118; 125) 'g(1u64)': i32
-    [120; 124) '1u64': u64
-    [135; 136) 'h': |u128| -> u128
-    [139; 152) '|v| 1u128 + v': |u128| -> u128
-    [140; 141) 'v': u128
-    [143; 148) '1u128': u128
-    [143; 152) '1u128 + v': u128
-    [151; 152) 'v': u128
-    "###
-    );
-}
-
-#[test]
-fn closure_as_argument_inference_order() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "fn_once"]
-trait FnOnce<Args> {
-    type Output;
-}
-
-fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
-fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
-
-struct S;
-impl S {
-    fn method(self) -> u64;
-
-    fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
-    fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
-}
-
-fn test() {
-    let x1 = foo1(S, |s| s.method());
-    let x2 = foo2(|s| s.method(), S);
-    let x3 = S.foo1(S, |s| s.method());
-    let x4 = S.foo2(|s| s.method(), S);
-}
-"#),
-        @r###"
-    [95; 96) 'x': T
-    [101; 102) 'f': F
-    [112; 114) '{}': ()
-    [148; 149) 'f': F
-    [154; 155) 'x': T
-    [165; 167) '{}': ()
-    [202; 206) 'self': S
-    [254; 258) 'self': S
-    [260; 261) 'x': T
-    [266; 267) 'f': F
-    [277; 279) '{}': ()
-    [317; 321) 'self': S
-    [323; 324) 'f': F
-    [329; 330) 'x': T
-    [340; 342) '{}': ()
-    [356; 515) '{     ... S); }': ()
-    [366; 368) 'x1': u64
-    [371; 375) 'foo1': fn foo1<S, u64, |S| -> u64>(T, F) -> U
-    [371; 394) 'foo1(S...hod())': u64
-    [376; 377) 'S': S
-    [379; 393) '|s| s.method()': |S| -> u64
-    [380; 381) 's': S
-    [383; 384) 's': S
-    [383; 393) 's.method()': u64
-    [404; 406) 'x2': u64
-    [409; 413) 'foo2': fn foo2<S, u64, |S| -> u64>(F, T) -> U
-    [409; 432) 'foo2(|...(), S)': u64
-    [414; 428) '|s| s.method()': |S| -> u64
-    [415; 416) 's': S
-    [418; 419) 's': S
-    [418; 428) 's.method()': u64
-    [430; 431) 'S': S
-    [442; 444) 'x3': u64
-    [447; 448) 'S': S
-    [447; 472) 'S.foo1...hod())': u64
-    [454; 455) 'S': S
-    [457; 471) '|s| s.method()': |S| -> u64
-    [458; 459) 's': S
-    [461; 462) 's': S
-    [461; 471) 's.method()': u64
-    [482; 484) 'x4': u64
-    [487; 488) 'S': S
-    [487; 512) 'S.foo2...(), S)': u64
-    [494; 508) '|s| s.method()': |S| -> u64
-    [495; 496) 's': S
-    [498; 499) 's': S
-    [498; 508) 's.method()': u64
-    [510; 511) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn unselected_projection_in_trait_env_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait {
-    type Item;
-}
-
-trait Trait2 {
-    fn foo(&self) -> u32;
-}
-
-fn test<T: Trait>() where T::Item: Trait2 {
-    let x: T::Item = no_matter;
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn unselected_projection_in_trait_env_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait<T> {
-    type Item;
-}
-
-trait Trait2 {
-    fn foo(&self) -> u32;
-}
-
-fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
-    let x: T::Item = no_matter;
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-// FIXME this is currently a Salsa panic; it would be nicer if it just returned
-// in Unknown, and we should be able to do that once Salsa allows us to handle
-// the cycle. But at least it doesn't overflow for now.
-#[should_panic]
-fn unselected_projection_in_trait_env_cycle_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait {
-    type Item;
-}
-
-trait Trait2<T> {}
-
-fn test<T: Trait>() where T: Trait2<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
-"#,
-    );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-// FIXME this is currently a Salsa panic; it would be nicer if it just returned
-// in Unknown, and we should be able to do that once Salsa allows us to handle
-// the cycle. But at least it doesn't overflow for now.
-#[should_panic]
-fn unselected_projection_in_trait_env_cycle_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait<T> {
-    type Item;
-}
-
-fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
-"#,
-    );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
-}
-
 fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
-
+    let fn_def = expr.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
     let module = db.module_for_file(pos.file_id);
-    let crate_def_map = db.crate_def_map(module.krate);
-    for decl in crate_def_map[module.local_id].scope.declarations() {
-        if let ModuleDefId::FunctionId(func) = decl {
-            let (_body, source_map) = db.body_with_source_map(func.into());
-            if let Some(expr_id) = source_map.node_expr(Source::new(pos.file_id.into(), &expr)) {
-                let infer = db.infer(func.into());
-                let ty = &infer[expr_id];
-                return ty.display(db).to_string();
-            }
-        }
+    let func = *module.child_by_source(db)[keys::FUNCTION]
+        .get(&InFile::new(pos.file_id.into(), fn_def))
+        .unwrap();
+
+    let (_body, source_map) = db.body_with_source_map(func.into());
+    if let Some(expr_id) = source_map.node_expr(InFile::new(pos.file_id.into(), &expr)) {
+        let infer = db.infer(func.into());
+        let ty = &infer[expr_id];
+        return ty.display(db).to_string();
     }
     panic!("Can't find expression")
 }
@@ -4696,6 +52,10 @@ fn type_at(content: &str) -> String {
 }
 
 fn infer(content: &str) -> String {
+    infer_with_mismatches(content, false)
+}
+
+fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
     let (db, file_id) = TestDB::with_single_file(content);
 
     let mut acc = String::new();
@@ -4703,6 +63,7 @@ fn infer(content: &str) -> String {
     let mut infer_def = |inference_result: Arc<InferenceResult>,
                          body_source_map: Arc<BodySourceMap>| {
         let mut types = Vec::new();
+        let mut mismatches = Vec::new();
 
         for (pat, ty) in inference_result.type_of_pat.iter() {
             let syntax_ptr = match body_source_map.pat_syntax(pat) {
@@ -4722,6 +83,9 @@ fn infer(content: &str) -> String {
                 None => continue,
             };
             types.push((syntax_ptr, ty));
+            if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr) {
+                mismatches.push((syntax_ptr, mismatch));
+            }
         }
 
         // sort ranges for consistency
@@ -4747,6 +111,24 @@ fn infer(content: &str) -> String {
             )
             .unwrap();
         }
+        if include_mismatches {
+            mismatches.sort_by_key(|(src_ptr, _)| {
+                (src_ptr.value.range().start(), src_ptr.value.range().end())
+            });
+            for (src_ptr, mismatch) in &mismatches {
+                let range = src_ptr.value.range();
+                let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
+                write!(
+                    acc,
+                    "{}{}: expected {}, got {}\n",
+                    macro_prefix,
+                    range,
+                    mismatch.expected.display(&db),
+                    mismatch.actual.display(&db),
+                )
+                .unwrap();
+            }
+        }
     };
 
     let module = db.module_for_file(file_id);
@@ -4800,7 +182,7 @@ fn visit_module(
             _ => (),
         }
     }
-    for &impl_id in crate_def_map[module_id].impls.iter() {
+    for impl_id in crate_def_map[module_id].scope.impls() {
         let impl_data = db.impl_data(impl_id);
         for &item in impl_data.items.iter() {
             match item {
@@ -4899,60 +281,3 @@ fn no_such_field_diagnostics() {
     "###
     );
 }
-
-#[test]
-fn infer_builtin_macros_line() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! line {() => {}}
-
-fn main() {
-    let x = line!();
-}
-"#),
-        @r###"
-    ![0; 1) '6': i32
-    [64; 88) '{     ...!(); }': ()
-    [74; 75) 'x': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_builtin_macros_file() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! file {() => {}}
-
-fn main() {
-    let x = file!();
-}
-"#),
-        @r###"
-    ![0; 2) '""': &str
-    [64; 88) '{     ...!(); }': ()
-    [74; 75) 'x': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_builtin_macros_column() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! column {() => {}}
-
-fn main() {
-    let x = column!();
-}
-"#),
-        @r###"
-    ![0; 2) '13': i32
-    [66; 92) '{     ...!(); }': ()
-    [76; 77) 'x': i32
-    "###
-    );
-}
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 1530fcc63..7e99a42ed 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -1,3 +1,4 @@
+use super::infer_with_mismatches;
 use insta::assert_snapshot;
 use test_utils::covers;
 
@@ -367,3 +368,161 @@ fn test() {
     "###
     );
 }
+
+#[test]
+fn return_coerce_unknown() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo() -> u32 {
+    return unknown;
+}
+"#, true),
+        @r###"
+    [17; 40) '{     ...own; }': !
+    [23; 37) 'return unknown': !
+    [30; 37) 'unknown': u32
+    "###
+    );
+}
+
+#[test]
+fn coerce_autoderef() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+struct Foo;
+fn takes_ref_foo(x: &Foo) {}
+fn test() {
+    takes_ref_foo(&Foo);
+    takes_ref_foo(&&Foo);
+    takes_ref_foo(&&&Foo);
+}
+"#, true),
+        @r###"
+    [30; 31) 'x': &Foo
+    [39; 41) '{}': ()
+    [52; 133) '{     ...oo); }': ()
+    [58; 71) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [58; 77) 'takes_...(&Foo)': ()
+    [72; 76) '&Foo': &Foo
+    [73; 76) 'Foo': Foo
+    [83; 96) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [83; 103) 'takes_...&&Foo)': ()
+    [97; 102) '&&Foo': &&Foo
+    [98; 102) '&Foo': &Foo
+    [99; 102) 'Foo': Foo
+    [109; 122) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [109; 130) 'takes_...&&Foo)': ()
+    [123; 129) '&&&Foo': &&&Foo
+    [124; 129) '&&Foo': &&Foo
+    [125; 129) '&Foo': &Foo
+    [126; 129) 'Foo': Foo
+    "###
+    );
+}
+
+#[test]
+fn coerce_autoderef_generic() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+struct Foo;
+fn takes_ref<T>(x: &T) -> T { *x }
+fn test() {
+    takes_ref(&Foo);
+    takes_ref(&&Foo);
+    takes_ref(&&&Foo);
+}
+"#, true),
+        @r###"
+    [29; 30) 'x': &T
+    [41; 47) '{ *x }': T
+    [43; 45) '*x': T
+    [44; 45) 'x': &T
+    [58; 127) '{     ...oo); }': ()
+    [64; 73) 'takes_ref': fn takes_ref<Foo>(&T) -> T
+    [64; 79) 'takes_ref(&Foo)': Foo
+    [74; 78) '&Foo': &Foo
+    [75; 78) 'Foo': Foo
+    [85; 94) 'takes_ref': fn takes_ref<&Foo>(&T) -> T
+    [85; 101) 'takes_...&&Foo)': &Foo
+    [95; 100) '&&Foo': &&Foo
+    [96; 100) '&Foo': &Foo
+    [97; 100) 'Foo': Foo
+    [107; 116) 'takes_ref': fn takes_ref<&&Foo>(&T) -> T
+    [107; 124) 'takes_...&&Foo)': &&Foo
+    [117; 123) '&&&Foo': &&&Foo
+    [118; 123) '&&Foo': &&Foo
+    [119; 123) '&Foo': &Foo
+    [120; 123) 'Foo': Foo
+    "###
+    );
+}
+
+#[test]
+fn closure_return_coerce() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo() {
+    let x = || {
+        if true {
+            return &1u32;
+        }
+        &&1u32
+    };
+}
+"#, true),
+        @r###"
+    [10; 106) '{     ...  }; }': ()
+    [20; 21) 'x': || -> &u32
+    [24; 103) '|| {  ...     }': || -> &u32
+    [27; 103) '{     ...     }': &u32
+    [37; 82) 'if tru...     }': ()
+    [40; 44) 'true': bool
+    [45; 82) '{     ...     }': !
+    [59; 71) 'return &1u32': !
+    [66; 71) '&1u32': &u32
+    [67; 71) '1u32': u32
+    [91; 97) '&&1u32': &&u32
+    [92; 97) '&1u32': &u32
+    [93; 97) '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn coerce_fn_item_to_fn_ptr() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo(x: u32) -> isize { 1 }
+fn test() {
+    let f: fn(u32) -> isize = foo;
+}
+"#, true),
+        @r###"
+    [8; 9) 'x': u32
+    [25; 30) '{ 1 }': isize
+    [27; 28) '1': isize
+    [41; 79) '{     ...foo; }': ()
+    [51; 52) 'f': fn(u32) -> isize
+    [73; 76) 'foo': fn foo(u32) -> isize
+    "###
+    );
+}
+
+#[test]
+fn coerce_closure_to_fn_ptr() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn test() {
+    let f: fn(u32) -> isize = |x| { 1 };
+}
+"#, true),
+        @r###"
+    [11; 55) '{     ...1 }; }': ()
+    [21; 22) 'f': fn(u32) -> isize
+    [43; 52) '|x| { 1 }': |u32| -> isize
+    [44; 45) 'x': u32
+    [47; 52) '{ 1 }': isize
+    [49; 50) '1': isize
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
new file mode 100644
index 000000000..69c695cc8
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -0,0 +1,390 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn cfg_impl_block() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo cfg:test
+use foo::S as T;
+struct S;
+
+#[cfg(test)]
+impl S {
+    fn foo1(&self) -> i32 { 0 }
+}
+
+#[cfg(not(test))]
+impl S {
+    fn foo2(&self) -> i32 { 0 }
+}
+
+fn test() {
+    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
+    t<|>;
+}
+
+//- /foo.rs crate:foo
+struct S;
+
+#[cfg(not(test))]
+impl S {
+    fn foo3(&self) -> i32 { 0 }
+}
+
+#[cfg(test)]
+impl S {
+    fn foo4(&self) -> i32 { 0 }
+}
+"#,
+    );
+    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+macro_rules! foo {
+    ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+    };
+}
+
+fn main() {
+    let x = foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [156; 182) '{     ...,2); }': ()
+    [166; 167) 'x': Foo
+    "###
+    );
+}
+
+#[test]
+fn infer_legacy_textual_scoped_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+#[macro_use]
+mod m {
+    macro_rules! foo {
+        ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+        };
+    }
+}
+
+fn main() {
+    let x = foo!(1,2);
+    let y = crate::foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [195; 251) '{     ...,2); }': ()
+    [205; 206) 'x': Foo
+    [228; 229) 'y': {unknown}
+    [232; 248) 'crate:...!(1,2)': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_path_qualified_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => { 42i32 }
+}
+
+mod m {
+    pub use super::foo as bar;
+}
+
+fn main() {
+    let x = crate::foo!();
+    let y = m::bar!();
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    ![0; 5) '42i32': i32
+    [111; 164) '{     ...!(); }': ()
+    [121; 122) 'x': i32
+    [148; 149) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_value_macro_having_same_name() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => {
+        mod foo {
+            pub use super::foo;
+        }
+    };
+    ($x:tt) => {
+        $x
+    };
+}
+
+foo!();
+
+fn foo() {
+    let foo = foo::foo!(42i32);
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    [171; 206) '{     ...32); }': ()
+    [181; 184) 'foo': i32
+    "###
+    );
+}
+
+#[test]
+fn processes_impls_generated_by_macros() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m {
+    ($ident:ident) => (impl Trait for $ident {})
+}
+trait Trait { fn foo(self) -> u128 {} }
+struct S;
+m!(S);
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_impl_items_generated_by_macros() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m {
+    () => (fn foo(&self) -> u128 {0})
+}
+struct S;
+impl S {
+    m!();
+}
+
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_impl_items_generated_by_macros_chain() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m_inner {
+    () => {fn foo(&self) -> u128 {0}}
+}
+macro_rules! m {
+    () => {m_inner!();}
+}
+
+struct S;
+impl S {
+    m!();
+}
+
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_macro_with_dollar_crate_is_correct_in_expr() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo
+fn test() {
+    let x = (foo::foo!(1), foo::foo!(2));
+    x<|>;
+}
+
+//- /lib.rs crate:foo
+#[macro_export]
+macro_rules! foo {
+    (1) => { $crate::bar!() };
+    (2) => { 1 + $crate::baz() };
+}
+
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+
+pub fn baz() -> usize { 31usize }
+"#,
+    );
+    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_type_value_non_legacy_macro_use_as() {
+    assert_snapshot!(
+        infer(r#"
+mod m {
+    macro_rules! _foo {
+        ($x:ident) => { type $x = u64; }
+    }
+    pub(crate) use _foo as foo;
+}
+
+m::foo!(foo);
+use foo as bar;
+fn f() -> bar { 0 }
+fn main() {  
+    let _a  = f();
+}
+"#),
+        @r###"
+        [159; 164) '{ 0 }': u64
+        [161; 162) '0': u64
+        [175; 199) '{     ...f(); }': ()
+        [187; 189) '_a': u64
+        [193; 194) 'f': fn f() -> u64
+        [193; 196) 'f()': u64        
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_line() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! line {() => {}}
+
+fn main() {
+    let x = line!();
+}
+"#),
+        @r###"
+    ![0; 1) '6': i32
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_file() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! file {() => {}}
+
+fn main() {
+    let x = file!();
+}
+"#),
+        @r###"
+    ![0; 2) '""': &str
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_column() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! column {() => {}}
+
+fn main() {
+    let x = column!();
+}
+"#),
+        @r###"
+    ![0; 2) '13': i32
+    [66; 92) '{     ...!(); }': ()
+    [76; 77) 'x': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_derive_clone_simple() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+#[derive(Clone)]
+struct S;
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:std
+#[prelude_import]
+use clone::*;
+mod clone {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_derive_clone_with_params() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+#[derive(Clone)]
+struct S;
+#[derive(Clone)]
+struct Wrapper<T>(T);
+struct NonClone;
+fn test() {
+    (Wrapper(S).clone(), Wrapper(NonClone).clone())<|>;
+}
+
+//- /lib.rs crate:std
+#[prelude_import]
+use clone::*;
+mod clone {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("(Wrapper<S>, {unknown})", type_at_pos(&db, pos));
+}
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
new file mode 100644
index 000000000..ce9a06fde
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -0,0 +1,1005 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_slice_method() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "slice"]
+impl<T> [T] {
+    fn foo(&self) -> T {
+        loop {}
+    }
+}
+
+#[lang = "slice_alloc"]
+impl<T> [T] {}
+
+fn test() {
+    <[_]>::foo(b"foo");
+}
+"#),
+        @r###"
+    [45; 49) 'self': &[T]
+    [56; 79) '{     ...     }': T
+    [66; 73) 'loop {}': !
+    [71; 73) '{}': ()
+    [133; 160) '{     ...o"); }': ()
+    [139; 149) '<[_]>::foo': fn foo<u8>(&[T]) -> T
+    [139; 157) '<[_]>:..."foo")': u8
+    [150; 156) 'b"foo"': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A { x: u32 }
+
+impl A {
+    fn new() -> A {
+        A { x: 0 }
+    }
+}
+fn test() {
+    let a = A::new();
+    a.x;
+}
+"#),
+        @r###"
+    [49; 75) '{     ...     }': A
+    [59; 69) 'A { x: 0 }': A
+    [66; 67) '0': u32
+    [88; 122) '{     ...a.x; }': ()
+    [98; 99) 'a': A
+    [102; 108) 'A::new': fn new() -> A
+    [102; 110) 'A::new()': A
+    [116; 117) 'a': A
+    [116; 119) 'a.x': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum A { B, C }
+
+impl A {
+    pub fn b() -> A {
+        A::B
+    }
+    pub fn c() -> A {
+        A::C
+    }
+}
+fn test() {
+    let a = A::b();
+    a;
+    let c = A::c();
+    c;
+}
+"#),
+        @r###"
+    [47; 67) '{     ...     }': A
+    [57; 61) 'A::B': A
+    [88; 108) '{     ...     }': A
+    [98; 102) 'A::C': A
+    [121; 178) '{     ...  c; }': ()
+    [131; 132) 'a': A
+    [135; 139) 'A::b': fn b() -> A
+    [135; 141) 'A::b()': A
+    [147; 148) 'a': A
+    [158; 159) 'c': A
+    [162; 166) 'A::c': fn c() -> A
+    [162; 168) 'A::c()': A
+    [174; 175) 'c': A
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_with_modules() {
+    assert_snapshot!(
+        infer(r#"
+mod a {
+    struct A;
+    impl A { pub fn thing() -> A { A {} }}
+}
+
+mod b {
+    struct B;
+    impl B { pub fn thing() -> u32 { 99 }}
+
+    mod c {
+        struct C;
+        impl C { pub fn thing() -> C { C {} }}
+    }
+}
+use b::c;
+
+fn test() {
+    let x = a::A::thing();
+    let y = b::B::thing();
+    let z = c::C::thing();
+}
+"#),
+        @r###"
+    [56; 64) '{ A {} }': A
+    [58; 62) 'A {}': A
+    [126; 132) '{ 99 }': u32
+    [128; 130) '99': u32
+    [202; 210) '{ C {} }': C
+    [204; 208) 'C {}': C
+    [241; 325) '{     ...g(); }': ()
+    [251; 252) 'x': A
+    [255; 266) 'a::A::thing': fn thing() -> A
+    [255; 268) 'a::A::thing()': A
+    [278; 279) 'y': u32
+    [282; 293) 'b::B::thing': fn thing() -> u32
+    [282; 295) 'b::B::thing()': u32
+    [305; 306) 'z': C
+    [309; 320) 'c::C::thing': fn thing() -> C
+    [309; 322) 'c::C::thing()': C
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make(val: T) -> Gen<T> {
+        Gen { val }
+    }
+}
+
+fn test() {
+    let a = Gen::make(0u32);
+}
+"#),
+        @r###"
+    [64; 67) 'val': T
+    [82; 109) '{     ...     }': Gen<T>
+    [92; 103) 'Gen { val }': Gen<T>
+    [98; 101) 'val': T
+    [123; 155) '{     ...32); }': ()
+    [133; 134) 'a': Gen<u32>
+    [137; 146) 'Gen::make': fn make<u32>(T) -> Gen<T>
+    [137; 152) 'Gen::make(0u32)': Gen<u32>
+    [147; 151) '0u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_param() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T=u32> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+}
+"#),
+        @r###"
+    [80; 104) '{     ...     }': Gen<T>
+    [90; 98) 'loop { }': !
+    [95; 98) '{ }': ()
+    [118; 146) '{     ...e(); }': ()
+    [128; 129) 'a': Gen<u32>
+    [132; 141) 'Gen::make': fn make<u32>() -> Gen<T>
+    [132; 143) 'Gen::make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_tuple_param() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct Gen<T=()> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+    a.val<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn infer_associated_method_generics_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32>::make();
+}
+"#),
+        @r###"
+    [76; 100) '{     ...     }': Gen<T>
+    [86; 94) 'loop { }': !
+    [91; 94) '{ }': ()
+    [114; 149) '{     ...e(); }': ()
+    [124; 125) 'a': Gen<u32>
+    [128; 144) 'Gen::<...::make': fn make<u32>() -> Gen<T>
+    [128; 146) 'Gen::<...make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_2_type_params_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T, U> {
+    val: T,
+    val2: U,
+}
+
+impl<T> Gen<u32, T> {
+    pub fn make() -> Gen<u32,T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32, u64>::make();
+}
+"#),
+        @r###"
+    [102; 126) '{     ...     }': Gen<u32, T>
+    [112; 120) 'loop { }': !
+    [117; 120) '{ }': ()
+    [140; 180) '{     ...e(); }': ()
+    [150; 151) 'a': Gen<u32, u64>
+    [154; 175) 'Gen::<...::make': fn make<u64>() -> Gen<u32, T>
+    [154; 177) 'Gen::<...make()': Gen<u32, u64>
+    "###
+    );
+}
+
+#[test]
+fn cross_crate_associated_method_call() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+fn test() {
+    let x = other_crate::foo::S::thing();
+    x<|>;
+}
+
+//- /lib.rs crate:other_crate
+mod foo {
+    struct S;
+    impl S {
+        fn thing() -> i128 {}
+    }
+}
+"#,
+    );
+    assert_eq!("i128", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_trait_method_simple() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    fn method(&self) -> u32;
+}
+struct S1;
+impl Trait1 for S1 {}
+trait Trait2 {
+    fn method(&self) -> i128;
+}
+struct S2;
+impl Trait2 for S2 {}
+fn test() {
+    S1.method(); // -> u32
+    S2.method(); // -> i128
+}
+"#),
+        @r###"
+    [31; 35) 'self': &Self
+    [110; 114) 'self': &Self
+    [170; 228) '{     ...i128 }': ()
+    [176; 178) 'S1': S1
+    [176; 187) 'S1.method()': u32
+    [203; 205) 'S2': S2
+    [203; 214) 'S2.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_scoped() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+struct S;
+mod foo {
+    pub trait Trait1 {
+        fn method(&self) -> u32;
+    }
+    impl Trait1 for super::S {}
+}
+mod bar {
+    pub trait Trait2 {
+        fn method(&self) -> i128;
+    }
+    impl Trait2 for super::S {}
+}
+
+mod foo_test {
+    use super::S;
+    use super::foo::Trait1;
+    fn test() {
+        S.method(); // -> u32
+    }
+}
+
+mod bar_test {
+    use super::S;
+    use super::bar::Trait2;
+    fn test() {
+        S.method(); // -> i128
+    }
+}
+"#),
+        @r###"
+    [63; 67) 'self': &Self
+    [169; 173) 'self': &Self
+    [300; 337) '{     ...     }': ()
+    [310; 311) 'S': S
+    [310; 320) 'S.method()': u32
+    [416; 454) '{     ...     }': ()
+    [426; 427) 'S': S
+    [426; 436) 'S.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_1() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+fn test() {
+    S.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [92; 111) '{     ...d(); }': ()
+    [98; 99) 'S': S
+    [98; 108) 'S.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_more_params() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T1, T2, T3> {
+    fn method1(&self) -> (T1, T2, T3);
+    fn method2(&self) -> (T3, T2, T1);
+}
+struct S1;
+impl Trait<u8, u16, u32> for S1 {}
+struct S2;
+impl<T> Trait<i8, i16, T> for S2 {}
+fn test() {
+    S1.method1(); // u8, u16, u32
+    S1.method2(); // u32, u16, u8
+    S2.method1(); // i8, i16, {unknown}
+    S2.method2(); // {unknown}, i16, i8
+}
+"#),
+        @r###"
+    [43; 47) 'self': &Self
+    [82; 86) 'self': &Self
+    [210; 361) '{     ..., i8 }': ()
+    [216; 218) 'S1': S1
+    [216; 228) 'S1.method1()': (u8, u16, u32)
+    [250; 252) 'S1': S1
+    [250; 262) 'S1.method2()': (u32, u16, u8)
+    [284; 286) 'S2': S2
+    [284; 296) 'S2.method1()': (i8, i16, {unknown})
+    [324; 326) 'S2': S2
+    [324; 336) 'S2.method2()': ({unknown}, i16, i8)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_2() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn test() {
+    S(1u32).method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [102; 127) '{     ...d(); }': ()
+    [108; 109) 'S': S<u32>(T) -> S<T>
+    [108; 115) 'S(1u32)': S<u32>
+    [108; 124) 'S(1u32...thod()': u32
+    [110; 114) '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method() {
+    assert_snapshot!(
+        infer(r#"
+trait Default {
+    fn default() -> Self;
+}
+struct S;
+impl Default for S {}
+fn test() {
+    let s1: S = Default::default();
+    let s2 = S::default();
+    let s3 = <S as Default>::default();
+}
+"#),
+        @r###"
+    [87; 193) '{     ...t(); }': ()
+    [97; 99) 's1': S
+    [105; 121) 'Defaul...efault': fn default<S>() -> Self
+    [105; 123) 'Defaul...ault()': S
+    [133; 135) 's2': S
+    [138; 148) 'S::default': fn default<S>() -> Self
+    [138; 150) 'S::default()': S
+    [160; 162) 's3': S
+    [165; 188) '<S as ...efault': fn default<S>() -> Self
+    [165; 190) '<S as ...ault()': S
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make();
+    let b = G::<u64>::make();
+    let c: f64 = G::make();
+}
+"#),
+        @r###"
+    [127; 211) '{     ...e(); }': ()
+    [137; 138) 'a': u32
+    [141; 148) 'S::make': fn make<S, u32>() -> T
+    [141; 150) 'S::make()': u32
+    [160; 161) 'b': u64
+    [164; 178) 'G::<u64>::make': fn make<G<u64>, u64>() -> T
+    [164; 180) 'G::<u6...make()': u64
+    [190; 191) 'c': f64
+    [199; 206) 'G::make': fn make<G<f64>, f64>() -> T
+    [199; 208) 'G::make()': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (T, U);
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make::<i64>();
+    let b: (_, i64) = S::make();
+    let c = G::<u32>::make::<i64>();
+    let d: (u32, _) = G::make::<i64>();
+    let e: (u32, i64) = G::make();
+}
+"#),
+        @r###"
+    [135; 313) '{     ...e(); }': ()
+    [145; 146) 'a': (u32, i64)
+    [149; 163) 'S::make::<i64>': fn make<S, u32, i64>() -> (T, U)
+    [149; 165) 'S::mak...i64>()': (u32, i64)
+    [175; 176) 'b': (u32, i64)
+    [189; 196) 'S::make': fn make<S, u32, i64>() -> (T, U)
+    [189; 198) 'S::make()': (u32, i64)
+    [208; 209) 'c': (u32, i64)
+    [212; 233) 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [212; 235) 'G::<u3...i64>()': (u32, i64)
+    [245; 246) 'd': (u32, i64)
+    [259; 273) 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [259; 275) 'G::mak...i64>()': (u32, i64)
+    [285; 286) 'e': (u32, i64)
+    [301; 308) 'G::make': fn make<G<u32>, u32, i64>() -> (T, U)
+    [301; 310) 'G::make()': (u32, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_3() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<i32> {}
+fn test() {
+    let a = S::make();
+}
+"#),
+        @r###"
+    [101; 127) '{     ...e(); }': ()
+    [111; 112) 'a': (S<i32>, i64)
+    [115; 122) 'S::make': fn make<S<i32>, i64>() -> (Self, T)
+    [115; 124) 'S::make()': (S<i32>, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_4() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+impl Trait<i32> for S<u32> {}
+fn test() {
+    let a: (S<u64>, _) = S::make();
+    let b: (_, i32) = S::make();
+}
+"#),
+        @r###"
+    [131; 203) '{     ...e(); }': ()
+    [141; 142) 'a': (S<u64>, i64)
+    [158; 165) 'S::make': fn make<S<u64>, i64>() -> (Self, T)
+    [158; 167) 'S::make()': (S<u64>, i64)
+    [177; 178) 'b': (S<u32>, i32)
+    [191; 198) 'S::make': fn make<S<u32>, i32>() -> (Self, T)
+    [191; 200) 'S::make()': (S<u32>, i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_5() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (Self, T, U);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+fn test() {
+    let a = <S as Trait<i64>>::make::<u8>();
+    let b: (S<u64>, _, _) = Trait::<i64>::make::<u8>();
+}
+"#),
+        @r###"
+    [107; 211) '{     ...>(); }': ()
+    [117; 118) 'a': (S<u64>, i64, u8)
+    [121; 150) '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [121; 152) '<S as ...<u8>()': (S<u64>, i64, u8)
+    [162; 163) 'b': (S<u64>, i64, u8)
+    [182; 206) 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [182; 208) 'Trait:...<u8>()': (S<u64>, i64, u8)
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn method(&self) -> u32;
+}
+fn test<T: Trait>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [64; 65) 't': T
+    [70; 89) '{     ...d(); }': ()
+    [76; 77) 't': T
+    [76; 86) 't.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+fn test<U, T: Trait<U>>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [71; 72) 't': T
+    [77; 96) '{     ...d(); }': ()
+    [83; 84) 't': T
+    [83; 93) 't.method()': [missing name]
+    "###
+    );
+}
+
+#[test]
+fn infer_with_multiple_trait_impls() {
+    assert_snapshot!(
+        infer(r#"
+trait Into<T> {
+    fn into(self) -> T;
+}
+struct S;
+impl Into<u32> for S {}
+impl Into<u64> for S {}
+fn test() {
+    let x: u32 = S.into();
+    let y: u64 = S.into();
+    let z = Into::<u64>::into(S);
+}
+"#),
+        @r###"
+    [29; 33) 'self': Self
+    [111; 202) '{     ...(S); }': ()
+    [121; 122) 'x': u32
+    [130; 131) 'S': S
+    [130; 138) 'S.into()': u32
+    [148; 149) 'y': u64
+    [157; 158) 'S': S
+    [157; 165) 'S.into()': u64
+    [175; 176) 'z': u64
+    [179; 196) 'Into::...::into': fn into<S, u64>(Self) -> T
+    [179; 199) 'Into::...nto(S)': u64
+    [197; 198) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn method_resolution_unify_impl_self_type() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S<T>;
+impl S<u32> { fn foo(&self) -> u8 {} }
+impl S<i32> { fn foo(&self) -> i8 {} }
+fn test() { (S::<u32>.foo(), S::<i32>.foo())<|>; }
+"#,
+    );
+    assert_eq!(t, "(u8, i8)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_by_value_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone { fn clone(&self) -> Self; }
+struct S;
+impl Clone for S {}
+impl Clone for &S {}
+fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
+"#,
+    );
+    assert_eq!(t, "(S, S, &S)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_impl_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_impl_ref_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_trait_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_trait_from_prelude() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+struct S;
+impl Clone for S {}
+
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:other_crate
+#[prelude_import] use foo::*;
+
+mod foo {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
+#[test]
+fn method_resolution_where_clause_for_unknown_trait() {
+    // The blanket impl currently applies because we ignore the unresolved where clause
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: UnknownTrait {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_where_clause_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: Clone {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    // This is also to make sure that we don't resolve to the foo method just
+    // because that's the only method named foo we can find, which would make
+    // the below tests not work
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T: Clone> Trait for T {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_where_clause_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U> Into<U> for T where U: From<T> {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U: From<T>> Into<U> for T {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_encountering_fn_type() {
+    type_at(
+        r#"
+//- /main.rs
+fn foo() {}
+trait FnOnce { fn call(self); }
+fn test() { foo.call()<|>; }
+"#,
+    );
+}
+
+#[test]
+fn method_resolution_slow() {
+    // this can get quite slow if we set the solver size limit too high
+    let t = type_at(
+        r#"
+//- /main.rs
+trait SendX {}
+
+struct S1; impl SendX for S1 {}
+struct S2; impl SendX for S2 {}
+struct U1;
+
+trait Trait { fn method(self); }
+
+struct X1<A, B> {}
+impl<A, B> SendX for X1<A, B> where A: SendX, B: SendX {}
+
+struct S<B, C> {}
+
+trait FnX {}
+
+impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
+
+fn test() { (S {}).method()<|>; }
+"#,
+    );
+    assert_eq!(t, "()");
+}
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
new file mode 100644
index 000000000..cb3890b42
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -0,0 +1,238 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn infer_pattern() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &i32) {
+    let y = x;
+    let &z = x;
+    let a = z;
+    let (c, d) = (1, "hello");
+
+    for (e, f) in some_iter {
+        let g = e;
+    }
+
+    if let [val] = opt {
+        let h = val;
+    }
+
+    let lambda = |a: u64, b, c: i32| { a + b; c };
+
+    let ref ref_to_x = x;
+    let mut mut_x = x;
+    let ref mut mut_ref_to_x = x;
+    let k = mut_ref_to_x;
+}
+"#),
+        @r###"
+    [9; 10) 'x': &i32
+    [18; 369) '{     ...o_x; }': ()
+    [28; 29) 'y': &i32
+    [32; 33) 'x': &i32
+    [43; 45) '&z': &i32
+    [44; 45) 'z': i32
+    [48; 49) 'x': &i32
+    [59; 60) 'a': i32
+    [63; 64) 'z': i32
+    [74; 80) '(c, d)': (i32, &str)
+    [75; 76) 'c': i32
+    [78; 79) 'd': &str
+    [83; 95) '(1, "hello")': (i32, &str)
+    [84; 85) '1': i32
+    [87; 94) '"hello"': &str
+    [102; 152) 'for (e...     }': ()
+    [106; 112) '(e, f)': ({unknown}, {unknown})
+    [107; 108) 'e': {unknown}
+    [110; 111) 'f': {unknown}
+    [116; 125) 'some_iter': {unknown}
+    [126; 152) '{     ...     }': ()
+    [140; 141) 'g': {unknown}
+    [144; 145) 'e': {unknown}
+    [158; 205) 'if let...     }': ()
+    [165; 170) '[val]': {unknown}
+    [173; 176) 'opt': {unknown}
+    [177; 205) '{     ...     }': ()
+    [191; 192) 'h': {unknown}
+    [195; 198) 'val': {unknown}
+    [215; 221) 'lambda': |u64, u64, i32| -> i32
+    [224; 256) '|a: u6...b; c }': |u64, u64, i32| -> i32
+    [225; 226) 'a': u64
+    [233; 234) 'b': u64
+    [236; 237) 'c': i32
+    [244; 256) '{ a + b; c }': i32
+    [246; 247) 'a': u64
+    [246; 251) 'a + b': u64
+    [250; 251) 'b': u64
+    [253; 254) 'c': i32
+    [267; 279) 'ref ref_to_x': &&i32
+    [282; 283) 'x': &i32
+    [293; 302) 'mut mut_x': &i32
+    [305; 306) 'x': &i32
+    [316; 336) 'ref mu...f_to_x': &mut &i32
+    [339; 340) 'x': &i32
+    [350; 351) 'k': &mut &i32
+    [354; 366) 'mut_ref_to_x': &mut &i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+
+fn test() {
+    let A(n) = &A(1);
+    let A(n) = &mut A(1);
+}
+"#),
+    @r###"
+    [28; 79) '{     ...(1); }': ()
+    [38; 42) 'A(n)': A<i32>
+    [40; 41) 'n': &i32
+    [45; 50) '&A(1)': &A<i32>
+    [46; 47) 'A': A<i32>(T) -> A<T>
+    [46; 50) 'A(1)': A<i32>
+    [48; 49) '1': i32
+    [60; 64) 'A(n)': A<i32>
+    [62; 63) 'n': &mut i32
+    [67; 76) '&mut A(1)': &mut A<i32>
+    [72; 73) 'A': A<i32>(T) -> A<T>
+    [72; 76) 'A(1)': A<i32>
+    [74; 75) '1': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics_ref() {
+    covers!(match_ergonomics_ref);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let v = &(1, &2);
+    let (_, &w) = v;
+}
+"#),
+    @r###"
+    [11; 57) '{     ...= v; }': ()
+    [21; 22) 'v': &(i32, &i32)
+    [25; 33) '&(1, &2)': &(i32, &i32)
+    [26; 33) '(1, &2)': (i32, &i32)
+    [27; 28) '1': i32
+    [30; 32) '&2': &i32
+    [31; 32) '2': i32
+    [43; 50) '(_, &w)': (i32, &i32)
+    [44; 45) '_': i32
+    [47; 49) '&w': &i32
+    [48; 49) 'w': i32
+    [53; 54) 'v': &(i32, &i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_adt_pattern() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+    A { x: usize },
+    B
+}
+
+struct S(u32, E);
+
+fn test() {
+    let e = E::A { x: 3 };
+
+    let S(y, z) = foo;
+    let E::A { x: new_var } = e;
+
+    match e {
+        E::A { x } => x,
+        E::B if foo => 1,
+        E::B => 10,
+    };
+
+    let ref d @ E::A { .. } = e;
+    d;
+}
+"#),
+        @r###"
+    [68; 289) '{     ...  d; }': ()
+    [78; 79) 'e': E
+    [82; 95) 'E::A { x: 3 }': E
+    [92; 93) '3': usize
+    [106; 113) 'S(y, z)': S
+    [108; 109) 'y': u32
+    [111; 112) 'z': E
+    [116; 119) 'foo': S
+    [129; 148) 'E::A {..._var }': E
+    [139; 146) 'new_var': usize
+    [151; 152) 'e': E
+    [159; 245) 'match ...     }': usize
+    [165; 166) 'e': E
+    [177; 187) 'E::A { x }': E
+    [184; 185) 'x': usize
+    [191; 192) 'x': usize
+    [202; 206) 'E::B': E
+    [210; 213) 'foo': bool
+    [217; 218) '1': usize
+    [228; 232) 'E::B': E
+    [236; 238) '10': usize
+    [256; 275) 'ref d ...{ .. }': &E
+    [264; 275) 'E::A { .. }': E
+    [278; 279) 'e': E
+    [285; 286) 'd': &E
+    "###
+    );
+}
+
+#[test]
+fn infer_generics_in_patterns() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+enum Option<T> {
+    Some(T),
+    None,
+}
+
+fn test(a1: A<u32>, o: Option<u64>) {
+    let A { x: x2 } = a1;
+    let A::<i64> { x: x3 } = A { x: 1 };
+    match o {
+        Option::Some(t) => t,
+        _ => 1,
+    };
+}
+"#),
+        @r###"
+    [79; 81) 'a1': A<u32>
+    [91; 92) 'o': Option<u64>
+    [107; 244) '{     ...  }; }': ()
+    [117; 128) 'A { x: x2 }': A<u32>
+    [124; 126) 'x2': u32
+    [131; 133) 'a1': A<u32>
+    [143; 161) 'A::<i6...: x3 }': A<i64>
+    [157; 159) 'x3': i64
+    [164; 174) 'A { x: 1 }': A<i64>
+    [171; 172) '1': i64
+    [180; 241) 'match ...     }': u64
+    [186; 187) 'o': Option<u64>
+    [198; 213) 'Option::Some(t)': Option<u64>
+    [211; 212) 't': u64
+    [217; 218) 't': u64
+    [228; 229) '_': Option<u64>
+    [233; 234) '1': u64
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
new file mode 100644
index 000000000..09d684ac2
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -0,0 +1,333 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn bug_484() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+   let x = if true {};
+}
+"#),
+        @r###"
+    [11; 37) '{    l... {}; }': ()
+    [20; 21) 'x': ()
+    [24; 34) 'if true {}': ()
+    [27; 31) 'true': bool
+    [32; 34) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn no_panic_on_field_of_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum X {}
+
+fn test(x: X) {
+    x.some_field;
+}
+"#),
+        @r###"
+    [20; 21) 'x': X
+    [26; 47) '{     ...eld; }': ()
+    [32; 33) 'x': X
+    [32; 44) 'x.some_field': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn bug_585() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    X {};
+    match x {
+        A::B {} => (),
+        A::Y() => (),
+    }
+}
+"#),
+        @r###"
+    [11; 89) '{     ...   } }': ()
+    [17; 21) 'X {}': {unknown}
+    [27; 87) 'match ...     }': ()
+    [33; 34) 'x': {unknown}
+    [45; 52) 'A::B {}': {unknown}
+    [56; 58) '()': ()
+    [68; 74) 'A::Y()': {unknown}
+    [78; 80) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn bug_651() {
+    assert_snapshot!(
+        infer(r#"
+fn quux() {
+    let y = 92;
+    1 + y;
+}
+"#),
+        @r###"
+    [11; 41) '{     ...+ y; }': ()
+    [21; 22) 'y': i32
+    [25; 27) '92': i32
+    [33; 34) '1': i32
+    [33; 38) '1 + y': i32
+    [37; 38) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let y = unknown;
+    [y, &y];
+}
+"#),
+        @r###"
+    [11; 48) '{     ...&y]; }': ()
+    [21; 22) 'y': &{unknown}
+    [25; 32) 'unknown': &{unknown}
+    [38; 45) '[y, &y]': [&&{unknown};_]
+    [39; 40) 'y': &{unknown}
+    [42; 44) '&y': &&{unknown}
+    [43; 44) 'y': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars_2() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let x = unknown;
+    let y = unknown;
+    [(x, y), (&y, &x)];
+}
+"#),
+        @r###"
+    [11; 80) '{     ...x)]; }': ()
+    [21; 22) 'x': &&{unknown}
+    [25; 32) 'unknown': &&{unknown}
+    [42; 43) 'y': &&{unknown}
+    [46; 53) 'unknown': &&{unknown}
+    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
+    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
+    [61; 62) 'x': &&{unknown}
+    [64; 65) 'y': &&{unknown}
+    [68; 76) '(&y, &x)': (&&&{unknown}, &&&{unknown})
+    [69; 71) '&y': &&&{unknown}
+    [70; 71) 'y': &&{unknown}
+    [73; 75) '&x': &&&{unknown}
+    [74; 75) 'x': &&{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_1() {
+    // caused stack overflow, taken from std
+    assert_snapshot!(
+        infer(r#"
+enum Maybe<T> {
+    Real(T),
+    Fake,
+}
+
+fn write() {
+    match something_unknown {
+        Maybe::Real(ref mut something) => (),
+    }
+}
+"#),
+        @r###"
+    [54; 139) '{     ...   } }': ()
+    [60; 137) 'match ...     }': ()
+    [66; 83) 'someth...nknown': Maybe<{unknown}>
+    [94; 124) 'Maybe:...thing)': Maybe<{unknown}>
+    [106; 123) 'ref mu...ething': &mut {unknown}
+    [128; 130) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_2() {
+    covers!(type_var_resolves_to_int_var);
+    // caused "equating two type variables, ...", taken from std
+    assert_snapshot!(
+        infer(r#"
+fn test_line_buffer() {
+    &[0, b'\n', 1, b'\n'];
+}
+"#),
+        @r###"
+    [23; 53) '{     ...n']; }': ()
+    [29; 50) '&[0, b...b'\n']': &[u8;_]
+    [30; 50) '[0, b'...b'\n']': [u8;_]
+    [31; 32) '0': u8
+    [34; 39) 'b'\n'': u8
+    [41; 42) '1': u8
+    [44; 49) 'b'\n'': u8
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_3() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn compute() {
+    match nope!() {
+        SizeSkeleton::Pointer { non_zero: true, tail } => {}
+    }
+}
+"#),
+        @r###"
+    [18; 108) '{     ...   } }': ()
+    [24; 106) 'match ...     }': ()
+    [30; 37) 'nope!()': {unknown}
+    [48; 94) 'SizeSk...tail }': {unknown}
+    [82; 86) 'true': {unknown}
+    [88; 92) 'tail': {unknown}
+    [98; 100) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_4() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn primitive_type() {
+    match *self {
+        BorrowedRef { type_: Primitive(p), ..} => {},
+    }
+}
+"#),
+        @r###"
+    [25; 106) '{     ...   } }': ()
+    [31; 104) 'match ...     }': ()
+    [37; 42) '*self': {unknown}
+    [38; 42) 'self': {unknown}
+    [53; 91) 'Borrow...), ..}': {unknown}
+    [74; 86) 'Primitive(p)': {unknown}
+    [84; 85) 'p': {unknown}
+    [95; 97) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_5() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+fn extra_compiler_flags() {
+    for content in doesnt_matter {
+        let name = if doesnt_matter {
+            first
+        } else {
+            &content
+        };
+
+        let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
+            name
+        } else {
+            content
+        };
+    }
+}
+"#),
+        @r###"
+    [27; 323) '{     ...   } }': ()
+    [33; 321) 'for co...     }': ()
+    [37; 44) 'content': &{unknown}
+    [48; 61) 'doesnt_matter': {unknown}
+    [62; 321) '{     ...     }': ()
+    [76; 80) 'name': &&{unknown}
+    [83; 167) 'if doe...     }': &&{unknown}
+    [86; 99) 'doesnt_matter': bool
+    [100; 129) '{     ...     }': &&{unknown}
+    [114; 119) 'first': &&{unknown}
+    [135; 167) '{     ...     }': &&{unknown}
+    [149; 157) '&content': &&{unknown}
+    [150; 157) 'content': &{unknown}
+    [182; 189) 'content': &{unknown}
+    [192; 314) 'if ICE...     }': &{unknown}
+    [195; 232) 'ICE_RE..._VALUE': {unknown}
+    [195; 248) 'ICE_RE...&name)': bool
+    [242; 247) '&name': &&&{unknown}
+    [243; 247) 'name': &&{unknown}
+    [249; 277) '{     ...     }': &&{unknown}
+    [263; 267) 'name': &&{unknown}
+    [283; 314) '{     ...     }': &{unknown}
+    [297; 304) 'content': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_nested_generics_crash() {
+    // another crash found typechecking rustc
+    assert_snapshot!(
+        infer(r#"
+struct Canonical<V> {
+    value: V,
+}
+struct QueryResponse<V> {
+    value: V,
+}
+fn test<R>(query_response: Canonical<QueryResponse<R>>) {
+    &query_response.value;
+}
+"#),
+        @r###"
+    [92; 106) 'query_response': Canonical<QueryResponse<R>>
+    [137; 167) '{     ...lue; }': ()
+    [143; 164) '&query....value': &QueryResponse<R>
+    [144; 158) 'query_response': Canonical<QueryResponse<R>>
+    [144; 164) 'query_....value': QueryResponse<R>
+    "###
+    );
+}
+
+#[test]
+fn bug_1030() {
+    assert_snapshot!(infer(r#"
+struct HashSet<T, H>;
+struct FxHasher;
+type FxHashSet<T> = HashSet<T, FxHasher>;
+
+impl<T, H> HashSet<T, H> {
+    fn default() -> HashSet<T, H> {}
+}
+
+pub fn main_loop() {
+    FxHashSet::default();
+}
+"#),
+    @r###"
+    [144; 146) '{}': ()
+    [169; 198) '{     ...t(); }': ()
+    [175; 193) 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<T, H>
+    [175; 195) 'FxHash...ault()': HashSet<{unknown}, FxHasher>
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
new file mode 100644
index 000000000..3e5e163e3
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -0,0 +1,1663 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_box() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let x = box 1;
+    let t = (x, box x, box &1, box [1]);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+mod boxed {
+    pub struct Box<T: ?Sized> {
+        inner: *mut T,
+    }
+}
+
+"#,
+    );
+    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_adt_self() {
+    let (db, pos) = TestDB::with_position(
+        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_ranges() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+fn test() {
+    let a = ..;
+    let b = 1..;
+    let c = ..2u32;
+    let d = 1..2usize;
+    let e = ..=10;
+    let f = 'a'..='z';
+
+    let t = (a, b, c, d, e, f);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+pub mod ops {
+    pub struct Range<Idx> {
+        pub start: Idx,
+        pub end: Idx,
+    }
+    pub struct RangeFrom<Idx> {
+        pub start: Idx,
+    }
+    struct RangeFull;
+    pub struct RangeInclusive<Idx> {
+        start: Idx,
+        end: Idx,
+        is_empty: u8,
+    }
+    pub struct RangeTo<Idx> {
+        pub end: Idx,
+    }
+    pub struct RangeToInclusive<Idx> {
+        pub end: Idx,
+    }
+}
+"#,
+    );
+    assert_eq!(
+        "(RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)",
+        type_at_pos(&db, pos),
+    );
+}
+
+#[test]
+fn infer_while_let() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+enum Option<T> { Some(T), None }
+
+fn test() {
+    let foo: Option<f32> = None;
+    while let Option::Some(x) = foo {
+        <|>x
+    }
+}
+
+"#,
+    );
+    assert_eq!("f32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_basics() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: u32, b: isize, c: !, d: &str) {
+    a;
+    b;
+    c;
+    d;
+    1usize;
+    1isize;
+    "test";
+    1.0f32;
+}"#),
+        @r###"
+    [9; 10) 'a': u32
+    [17; 18) 'b': isize
+    [27; 28) 'c': !
+    [33; 34) 'd': &str
+    [42; 121) '{     ...f32; }': !
+    [48; 49) 'a': u32
+    [55; 56) 'b': isize
+    [62; 63) 'c': !
+    [69; 70) 'd': &str
+    [76; 82) '1usize': usize
+    [88; 94) '1isize': isize
+    [100; 106) '"test"': &str
+    [112; 118) '1.0f32': f32
+    "###
+    );
+}
+
+#[test]
+fn infer_let() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let a = 1isize;
+    let b: usize = 1;
+    let c = b;
+    let d: u32;
+    let e;
+    let f: i32 = e;
+}
+"#),
+        @r###"
+    [11; 118) '{     ...= e; }': ()
+    [21; 22) 'a': isize
+    [25; 31) '1isize': isize
+    [41; 42) 'b': usize
+    [52; 53) '1': usize
+    [63; 64) 'c': usize
+    [67; 68) 'b': usize
+    [78; 79) 'd': u32
+    [94; 95) 'e': i32
+    [105; 106) 'f': i32
+    [114; 115) 'e': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_paths() {
+    assert_snapshot!(
+        infer(r#"
+fn a() -> u32 { 1 }
+
+mod b {
+    fn c() -> u32 { 1 }
+}
+
+fn test() {
+    a();
+    b::c();
+}
+"#),
+        @r###"
+    [15; 20) '{ 1 }': u32
+    [17; 18) '1': u32
+    [48; 53) '{ 1 }': u32
+    [50; 51) '1': u32
+    [67; 91) '{     ...c(); }': ()
+    [73; 74) 'a': fn a() -> u32
+    [73; 76) 'a()': u32
+    [82; 86) 'b::c': fn c() -> u32
+    [82; 88) 'b::c()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_path_type() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn foo() -> i32 { 1 }
+}
+
+fn test() {
+    S::foo();
+    <S>::foo();
+}
+"#),
+        @r###"
+    [41; 46) '{ 1 }': i32
+    [43; 44) '1': i32
+    [60; 93) '{     ...o(); }': ()
+    [66; 72) 'S::foo': fn foo() -> i32
+    [66; 74) 'S::foo()': i32
+    [80; 88) '<S>::foo': fn foo() -> i32
+    [80; 90) '<S>::foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+    c: C,
+}
+struct B;
+struct C(usize);
+
+fn test() {
+    let c = C(1);
+    B;
+    let a: A = A { b: B, c: C(1) };
+    a.b;
+    a.c;
+}
+"#),
+        @r###"
+    [72; 154) '{     ...a.c; }': ()
+    [82; 83) 'c': C
+    [86; 87) 'C': C(usize) -> C
+    [86; 90) 'C(1)': C
+    [88; 89) '1': usize
+    [96; 97) 'B': B
+    [107; 108) 'a': A
+    [114; 133) 'A { b:...C(1) }': A
+    [121; 122) 'B': B
+    [127; 128) 'C': C(usize) -> C
+    [127; 131) 'C(1)': C
+    [129; 130) '1': usize
+    [139; 140) 'a': A
+    [139; 142) 'a.b': B
+    [148; 149) 'a': A
+    [148; 151) 'a.c': C
+    "###
+    );
+}
+
+#[test]
+fn infer_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+  V1 { field: u32 },
+  V2
+}
+fn test() {
+  E::V1 { field: 1 };
+  E::V2;
+}"#),
+        @r###"
+    [48; 82) '{   E:...:V2; }': ()
+    [52; 70) 'E::V1 ...d: 1 }': E
+    [67; 68) '1': u32
+    [74; 79) 'E::V2': E
+    "###
+    );
+}
+
+#[test]
+fn infer_refs() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
+    a;
+    *a;
+    &a;
+    &mut a;
+    b;
+    *b;
+    &b;
+    c;
+    *c;
+    d;
+    *d;
+}
+"#),
+        @r###"
+    [9; 10) 'a': &u32
+    [18; 19) 'b': &mut u32
+    [31; 32) 'c': *const u32
+    [46; 47) 'd': *mut u32
+    [59; 150) '{     ... *d; }': ()
+    [65; 66) 'a': &u32
+    [72; 74) '*a': u32
+    [73; 74) 'a': &u32
+    [80; 82) '&a': &&u32
+    [81; 82) 'a': &u32
+    [88; 94) '&mut a': &mut &u32
+    [93; 94) 'a': &u32
+    [100; 101) 'b': &mut u32
+    [107; 109) '*b': u32
+    [108; 109) 'b': &mut u32
+    [115; 117) '&b': &&mut u32
+    [116; 117) 'b': &mut u32
+    [123; 124) 'c': *const u32
+    [130; 132) '*c': u32
+    [131; 132) 'c': *const u32
+    [138; 139) 'd': *mut u32
+    [145; 147) '*d': u32
+    [146; 147) 'd': *mut u32
+    "###
+    );
+}
+
+#[test]
+fn infer_literals() {
+    assert_snapshot!(
+        infer(r##"
+fn test() {
+    5i32;
+    5f32;
+    5f64;
+    "hello";
+    b"bytes";
+    'c';
+    b'b';
+    3.14;
+    5000;
+    false;
+    true;
+    r#"
+        //! doc
+        // non-doc
+        mod foo {}
+        "#;
+    br#"yolo"#;
+}
+"##),
+        @r###"
+    [11; 221) '{     ...o"#; }': ()
+    [17; 21) '5i32': i32
+    [27; 31) '5f32': f32
+    [37; 41) '5f64': f64
+    [47; 54) '"hello"': &str
+    [60; 68) 'b"bytes"': &[u8]
+    [74; 77) ''c'': char
+    [83; 87) 'b'b'': u8
+    [93; 97) '3.14': f64
+    [103; 107) '5000': i32
+    [113; 118) 'false': bool
+    [124; 128) 'true': bool
+    [134; 202) 'r#"   ...    "#': &str
+    [208; 218) 'br#"yolo"#': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_unary_op() {
+    assert_snapshot!(
+        infer(r#"
+enum SomeType {}
+
+fn test(x: SomeType) {
+    let b = false;
+    let c = !b;
+    let a = 100;
+    let d: i128 = -a;
+    let e = -100;
+    let f = !!!true;
+    let g = !42;
+    let h = !10u32;
+    let j = !a;
+    -3.14;
+    !3;
+    -x;
+    !x;
+    -"hello";
+    !"hello";
+}
+"#),
+        @r###"
+    [27; 28) 'x': SomeType
+    [40; 272) '{     ...lo"; }': ()
+    [50; 51) 'b': bool
+    [54; 59) 'false': bool
+    [69; 70) 'c': bool
+    [73; 75) '!b': bool
+    [74; 75) 'b': bool
+    [85; 86) 'a': i128
+    [89; 92) '100': i128
+    [102; 103) 'd': i128
+    [112; 114) '-a': i128
+    [113; 114) 'a': i128
+    [124; 125) 'e': i32
+    [128; 132) '-100': i32
+    [129; 132) '100': i32
+    [142; 143) 'f': bool
+    [146; 153) '!!!true': bool
+    [147; 153) '!!true': bool
+    [148; 153) '!true': bool
+    [149; 153) 'true': bool
+    [163; 164) 'g': i32
+    [167; 170) '!42': i32
+    [168; 170) '42': i32
+    [180; 181) 'h': u32
+    [184; 190) '!10u32': u32
+    [185; 190) '10u32': u32
+    [200; 201) 'j': i128
+    [204; 206) '!a': i128
+    [205; 206) 'a': i128
+    [212; 217) '-3.14': f64
+    [213; 217) '3.14': f64
+    [223; 225) '!3': i32
+    [224; 225) '3': i32
+    [231; 233) '-x': {unknown}
+    [232; 233) 'x': SomeType
+    [239; 241) '!x': {unknown}
+    [240; 241) 'x': SomeType
+    [247; 255) '-"hello"': {unknown}
+    [248; 255) '"hello"': &str
+    [261; 269) '!"hello"': {unknown}
+    [262; 269) '"hello"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_backwards() {
+    assert_snapshot!(
+        infer(r#"
+fn takes_u32(x: u32) {}
+
+struct S { i32_field: i32 }
+
+fn test() -> &mut &f64 {
+    let a = unknown_function();
+    takes_u32(a);
+    let b = unknown_function();
+    S { i32_field: b };
+    let c = unknown_function();
+    &mut &c
+}
+"#),
+        @r###"
+    [14; 15) 'x': u32
+    [22; 24) '{}': ()
+    [78; 231) '{     ...t &c }': &mut &f64
+    [88; 89) 'a': u32
+    [92; 108) 'unknow...nction': {unknown}
+    [92; 110) 'unknow...tion()': u32
+    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
+    [116; 128) 'takes_u32(a)': ()
+    [126; 127) 'a': u32
+    [138; 139) 'b': i32
+    [142; 158) 'unknow...nction': {unknown}
+    [142; 160) 'unknow...tion()': i32
+    [166; 184) 'S { i3...d: b }': S
+    [181; 182) 'b': i32
+    [194; 195) 'c': f64
+    [198; 214) 'unknow...nction': {unknown}
+    [198; 216) 'unknow...tion()': f64
+    [222; 229) '&mut &c': &mut &f64
+    [227; 229) '&c': &f64
+    [228; 229) 'c': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_self() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn test(&self) {
+        self;
+    }
+    fn test2(self: &Self) {
+        self;
+    }
+    fn test3() -> Self {
+        S {}
+    }
+    fn test4() -> Self {
+        Self {}
+    }
+}
+"#),
+        @r###"
+    [34; 38) 'self': &S
+    [40; 61) '{     ...     }': ()
+    [50; 54) 'self': &S
+    [75; 79) 'self': &S
+    [88; 109) '{     ...     }': ()
+    [98; 102) 'self': &S
+    [133; 153) '{     ...     }': S
+    [143; 147) 'S {}': S
+    [177; 200) '{     ...     }': S
+    [187; 194) 'Self {}': S
+    "###
+    );
+}
+
+#[test]
+fn infer_binary_op() {
+    assert_snapshot!(
+        infer(r#"
+fn f(x: bool) -> i32 {
+    0i32
+}
+
+fn test() -> bool {
+    let x = a && b;
+    let y = true || false;
+    let z = x == y;
+    let t = x != y;
+    let minus_forty: isize = -40isize;
+    let h = minus_forty <= CONST_2;
+    let c = f(z || y) + 5;
+    let d = b;
+    let g = minus_forty ^= i;
+    let ten: usize = 10;
+    let ten_is_eleven = ten == some_num;
+
+    ten < 3
+}
+"#),
+        @r###"
+    [6; 7) 'x': bool
+    [22; 34) '{     0i32 }': i32
+    [28; 32) '0i32': i32
+    [54; 370) '{     ... < 3 }': bool
+    [64; 65) 'x': bool
+    [68; 69) 'a': bool
+    [68; 74) 'a && b': bool
+    [73; 74) 'b': bool
+    [84; 85) 'y': bool
+    [88; 92) 'true': bool
+    [88; 101) 'true || false': bool
+    [96; 101) 'false': bool
+    [111; 112) 'z': bool
+    [115; 116) 'x': bool
+    [115; 121) 'x == y': bool
+    [120; 121) 'y': bool
+    [131; 132) 't': bool
+    [135; 136) 'x': bool
+    [135; 141) 'x != y': bool
+    [140; 141) 'y': bool
+    [151; 162) 'minus_forty': isize
+    [172; 180) '-40isize': isize
+    [173; 180) '40isize': isize
+    [190; 191) 'h': bool
+    [194; 205) 'minus_forty': isize
+    [194; 216) 'minus_...ONST_2': bool
+    [209; 216) 'CONST_2': isize
+    [226; 227) 'c': i32
+    [230; 231) 'f': fn f(bool) -> i32
+    [230; 239) 'f(z || y)': i32
+    [230; 243) 'f(z || y) + 5': i32
+    [232; 233) 'z': bool
+    [232; 238) 'z || y': bool
+    [237; 238) 'y': bool
+    [242; 243) '5': i32
+    [253; 254) 'd': {unknown}
+    [257; 258) 'b': {unknown}
+    [268; 269) 'g': ()
+    [272; 283) 'minus_forty': isize
+    [272; 288) 'minus_...y ^= i': ()
+    [287; 288) 'i': isize
+    [298; 301) 'ten': usize
+    [311; 313) '10': usize
+    [323; 336) 'ten_is_eleven': bool
+    [339; 342) 'ten': usize
+    [339; 354) 'ten == some_num': bool
+    [346; 354) 'some_num': usize
+    [361; 364) 'ten': usize
+    [361; 368) 'ten < 3': bool
+    [367; 368) '3': usize
+    "###
+    );
+}
+
+#[test]
+fn infer_field_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+}
+struct B;
+
+fn test1(a: A) {
+    let a1 = a;
+    a1.b;
+    let a2 = &a;
+    a2.b;
+    let a3 = &mut a;
+    a3.b;
+    let a4 = &&&&&&&a;
+    a4.b;
+    let a5 = &mut &&mut &&mut a;
+    a5.b;
+}
+
+fn test2(a1: *const A, a2: *mut A) {
+    a1.b;
+    a2.b;
+}
+"#),
+        @r###"
+    [44; 45) 'a': A
+    [50; 213) '{     ...5.b; }': ()
+    [60; 62) 'a1': A
+    [65; 66) 'a': A
+    [72; 74) 'a1': A
+    [72; 76) 'a1.b': B
+    [86; 88) 'a2': &A
+    [91; 93) '&a': &A
+    [92; 93) 'a': A
+    [99; 101) 'a2': &A
+    [99; 103) 'a2.b': B
+    [113; 115) 'a3': &mut A
+    [118; 124) '&mut a': &mut A
+    [123; 124) 'a': A
+    [130; 132) 'a3': &mut A
+    [130; 134) 'a3.b': B
+    [144; 146) 'a4': &&&&&&&A
+    [149; 157) '&&&&&&&a': &&&&&&&A
+    [150; 157) '&&&&&&a': &&&&&&A
+    [151; 157) '&&&&&a': &&&&&A
+    [152; 157) '&&&&a': &&&&A
+    [153; 157) '&&&a': &&&A
+    [154; 157) '&&a': &&A
+    [155; 157) '&a': &A
+    [156; 157) 'a': A
+    [163; 165) 'a4': &&&&&&&A
+    [163; 167) 'a4.b': B
+    [177; 179) 'a5': &mut &&mut &&mut A
+    [182; 200) '&mut &...&mut a': &mut &&mut &&mut A
+    [187; 200) '&&mut &&mut a': &&mut &&mut A
+    [188; 200) '&mut &&mut a': &mut &&mut A
+    [193; 200) '&&mut a': &&mut A
+    [194; 200) '&mut a': &mut A
+    [199; 200) 'a': A
+    [206; 208) 'a5': &mut &&mut &&mut A
+    [206; 210) 'a5.b': B
+    [224; 226) 'a1': *const A
+    [238; 240) 'a2': *mut A
+    [250; 273) '{     ...2.b; }': ()
+    [256; 258) 'a1': *const A
+    [256; 260) 'a1.b': B
+    [266; 268) 'a2': *mut A
+    [266; 270) 'a2.b': B
+    "###
+    );
+}
+
+#[test]
+fn infer_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(T);
+
+impl<T> A<T> {
+    fn foo(&self) -> &T {
+        &self.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test() {
+    let t = A::foo(&&B(B(A(42))));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [139; 143) 'self': &A<T>
+    [151; 174) '{     ...     }': &T
+    [161; 168) '&self.0': &T
+    [162; 166) 'self': &A<T>
+    [162; 168) 'self.0': T
+    [255; 259) 'self': &B<T>
+    [278; 301) '{     ...     }': &T
+    [288; 295) '&self.0': &T
+    [289; 293) 'self': &B<T>
+    [289; 295) 'self.0': T
+    [315; 353) '{     ...))); }': ()
+    [325; 326) 't': &i32
+    [329; 335) 'A::foo': fn foo<i32>(&A<T>) -> &T
+    [329; 350) 'A::foo...42))))': &i32
+    [336; 349) '&&B(B(A(42)))': &&B<B<A<i32>>>
+    [337; 349) '&B(B(A(42)))': &B<B<A<i32>>>
+    [338; 339) 'B': B<B<A<i32>>>(T) -> B<T>
+    [338; 349) 'B(B(A(42)))': B<B<A<i32>>>
+    [340; 341) 'B': B<A<i32>>(T) -> B<T>
+    [340; 348) 'B(A(42))': B<A<i32>>
+    [342; 343) 'A': A<i32>(T) -> A<T>
+    [342; 347) 'A(42)': A<i32>
+    [344; 346) '42': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_method_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(*mut T);
+
+impl<T> A<T> {
+    fn foo(&self, x: &A<T>) -> &T {
+        &*x.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test(a: A<i32>) {
+    let t = A(0 as *mut _).foo(&&B(B(a)));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [144; 148) 'self': &A<T>
+    [150; 151) 'x': &A<T>
+    [166; 187) '{     ...     }': &T
+    [176; 181) '&*x.0': &T
+    [177; 181) '*x.0': T
+    [178; 179) 'x': &A<T>
+    [178; 181) 'x.0': *mut T
+    [268; 272) 'self': &B<T>
+    [291; 314) '{     ...     }': &T
+    [301; 308) '&self.0': &T
+    [302; 306) 'self': &B<T>
+    [302; 308) 'self.0': T
+    [326; 327) 'a': A<i32>
+    [337; 383) '{     ...))); }': ()
+    [347; 348) 't': &i32
+    [351; 352) 'A': A<i32>(*mut T) -> A<T>
+    [351; 365) 'A(0 as *mut _)': A<i32>
+    [351; 380) 'A(0 as...B(a)))': &i32
+    [353; 354) '0': i32
+    [353; 364) '0 as *mut _': *mut i32
+    [370; 379) '&&B(B(a))': &&B<B<A<i32>>>
+    [371; 379) '&B(B(a))': &B<B<A<i32>>>
+    [372; 373) 'B': B<B<A<i32>>>(T) -> B<T>
+    [372; 379) 'B(B(a))': B<B<A<i32>>>
+    [374; 375) 'B': B<A<i32>>(T) -> B<T>
+    [374; 378) 'B(a)': B<A<i32>>
+    [376; 377) 'a': A<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_in_elseif() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo { field: i32 }
+fn main(foo: Foo) {
+    if true {
+
+    } else if false {
+        foo.field
+    }
+}
+"#),
+        @r###"
+    [35; 38) 'foo': Foo
+    [45; 109) '{     ...   } }': ()
+    [51; 107) 'if tru...     }': ()
+    [54; 58) 'true': bool
+    [59; 67) '{      }': ()
+    [73; 107) 'if fal...     }': ()
+    [76; 81) 'false': bool
+    [82; 107) '{     ...     }': i32
+    [92; 95) 'foo': Foo
+    [92; 101) 'foo.field': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_if_match_with_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() {
+    let _x1 = if true {
+        1
+    } else {
+        return;
+    };
+    let _x2 = if true {
+        2
+    } else {
+        return
+    };
+    let _x3 = match true {
+        true => 3,
+        _ => {
+            return;
+        }
+    };
+    let _x4 = match true {
+        true => 4,
+        _ => return
+    };
+}"#),
+        @r###"
+    [10; 323) '{     ...  }; }': ()
+    [20; 23) '_x1': i32
+    [26; 80) 'if tru...     }': i32
+    [29; 33) 'true': bool
+    [34; 51) '{     ...     }': i32
+    [44; 45) '1': i32
+    [57; 80) '{     ...     }': !
+    [67; 73) 'return': !
+    [90; 93) '_x2': i32
+    [96; 149) 'if tru...     }': i32
+    [99; 103) 'true': bool
+    [104; 121) '{     ...     }': i32
+    [114; 115) '2': i32
+    [127; 149) '{     ...     }': !
+    [137; 143) 'return': !
+    [159; 162) '_x3': i32
+    [165; 247) 'match ...     }': i32
+    [171; 175) 'true': bool
+    [186; 190) 'true': bool
+    [194; 195) '3': i32
+    [205; 206) '_': bool
+    [210; 241) '{     ...     }': !
+    [224; 230) 'return': !
+    [257; 260) '_x4': i32
+    [263; 320) 'match ...     }': i32
+    [269; 273) 'true': bool
+    [284; 288) 'true': bool
+    [292; 293) '4': i32
+    [303; 304) '_': bool
+    [308; 314) 'return': !
+    "###
+    )
+}
+
+#[test]
+fn infer_inherent_method() {
+    assert_snapshot!(
+        infer(r#"
+struct A;
+
+impl A {
+    fn foo(self, x: u32) -> i32 {}
+}
+
+mod b {
+    impl super::A {
+        fn bar(&self, x: u64) -> i64 {}
+    }
+}
+
+fn test(a: A) {
+    a.foo(1);
+    (&a).bar(1);
+    a.bar(1);
+}
+"#),
+        @r###"
+    [32; 36) 'self': A
+    [38; 39) 'x': u32
+    [53; 55) '{}': ()
+    [103; 107) 'self': &A
+    [109; 110) 'x': u64
+    [124; 126) '{}': ()
+    [144; 145) 'a': A
+    [150; 198) '{     ...(1); }': ()
+    [156; 157) 'a': A
+    [156; 164) 'a.foo(1)': i32
+    [162; 163) '1': u32
+    [170; 181) '(&a).bar(1)': i64
+    [171; 173) '&a': &A
+    [172; 173) 'a': A
+    [179; 180) '1': u64
+    [187; 188) 'a': A
+    [187; 195) 'a.bar(1)': i64
+    [193; 194) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_inherent_method_str() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "str"]
+impl str {
+    fn foo(&self) -> i32 {}
+}
+
+fn test() {
+    "foo".foo();
+}
+"#),
+        @r###"
+    [40; 44) 'self': &str
+    [53; 55) '{}': ()
+    [69; 89) '{     ...o(); }': ()
+    [75; 80) '"foo"': &str
+    [75; 86) '"foo".foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a: (u32, &str) = (1, "a");
+    let b = (a, x);
+    let c = (y, x);
+    let d = (c, x);
+    let e = (1, "e");
+    let f = (e, "d");
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 170) '{     ...d"); }': ()
+    [38; 39) 'a': (u32, &str)
+    [55; 63) '(1, "a")': (u32, &str)
+    [56; 57) '1': u32
+    [59; 62) '"a"': &str
+    [73; 74) 'b': ((u32, &str), &str)
+    [77; 83) '(a, x)': ((u32, &str), &str)
+    [78; 79) 'a': (u32, &str)
+    [81; 82) 'x': &str
+    [93; 94) 'c': (isize, &str)
+    [97; 103) '(y, x)': (isize, &str)
+    [98; 99) 'y': isize
+    [101; 102) 'x': &str
+    [113; 114) 'd': ((isize, &str), &str)
+    [117; 123) '(c, x)': ((isize, &str), &str)
+    [118; 119) 'c': (isize, &str)
+    [121; 122) 'x': &str
+    [133; 134) 'e': (i32, &str)
+    [137; 145) '(1, "e")': (i32, &str)
+    [138; 139) '1': i32
+    [141; 144) '"e"': &str
+    [155; 156) 'f': ((i32, &str), &str)
+    [159; 167) '(e, "d")': ((i32, &str), &str)
+    [160; 161) 'e': (i32, &str)
+    [163; 166) '"d"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_array() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a = [x];
+    let b = [a, a];
+    let c = [b, b];
+
+    let d = [y, 1, 2, 3];
+    let d = [1, y, 2, 3];
+    let e = [y];
+    let f = [d, d];
+    let g = [e, e];
+
+    let h = [1, 2];
+    let i = ["a", "b"];
+
+    let b = [a, ["b"]];
+    let x: [u8; 0] = [];
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 293) '{     ... []; }': ()
+    [38; 39) 'a': [&str;_]
+    [42; 45) '[x]': [&str;_]
+    [43; 44) 'x': &str
+    [55; 56) 'b': [[&str;_];_]
+    [59; 65) '[a, a]': [[&str;_];_]
+    [60; 61) 'a': [&str;_]
+    [63; 64) 'a': [&str;_]
+    [75; 76) 'c': [[[&str;_];_];_]
+    [79; 85) '[b, b]': [[[&str;_];_];_]
+    [80; 81) 'b': [[&str;_];_]
+    [83; 84) 'b': [[&str;_];_]
+    [96; 97) 'd': [isize;_]
+    [100; 112) '[y, 1, 2, 3]': [isize;_]
+    [101; 102) 'y': isize
+    [104; 105) '1': isize
+    [107; 108) '2': isize
+    [110; 111) '3': isize
+    [122; 123) 'd': [isize;_]
+    [126; 138) '[1, y, 2, 3]': [isize;_]
+    [127; 128) '1': isize
+    [130; 131) 'y': isize
+    [133; 134) '2': isize
+    [136; 137) '3': isize
+    [148; 149) 'e': [isize;_]
+    [152; 155) '[y]': [isize;_]
+    [153; 154) 'y': isize
+    [165; 166) 'f': [[isize;_];_]
+    [169; 175) '[d, d]': [[isize;_];_]
+    [170; 171) 'd': [isize;_]
+    [173; 174) 'd': [isize;_]
+    [185; 186) 'g': [[isize;_];_]
+    [189; 195) '[e, e]': [[isize;_];_]
+    [190; 191) 'e': [isize;_]
+    [193; 194) 'e': [isize;_]
+    [206; 207) 'h': [i32;_]
+    [210; 216) '[1, 2]': [i32;_]
+    [211; 212) '1': i32
+    [214; 215) '2': i32
+    [226; 227) 'i': [&str;_]
+    [230; 240) '["a", "b"]': [&str;_]
+    [231; 234) '"a"': &str
+    [236; 239) '"b"': &str
+    [251; 252) 'b': [[&str;_];_]
+    [255; 265) '[a, ["b"]]': [[&str;_];_]
+    [256; 257) 'a': [&str;_]
+    [259; 264) '["b"]': [&str;_]
+    [260; 263) '"b"': &str
+    [275; 276) 'x': [u8;_]
+    [288; 290) '[]': [u8;_]
+    "###
+    );
+}
+
+#[test]
+fn infer_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+fn test(a1: A<u32>, i: i32) {
+    a1.x;
+    let a2 = A { x: i };
+    a2.x;
+    let a3 = A::<i128> { x: 1 };
+    a3.x;
+}
+"#),
+        @r###"
+    [36; 38) 'a1': A<u32>
+    [48; 49) 'i': i32
+    [56; 147) '{     ...3.x; }': ()
+    [62; 64) 'a1': A<u32>
+    [62; 66) 'a1.x': u32
+    [76; 78) 'a2': A<i32>
+    [81; 91) 'A { x: i }': A<i32>
+    [88; 89) 'i': i32
+    [97; 99) 'a2': A<i32>
+    [97; 101) 'a2.x': i32
+    [111; 113) 'a3': A<i128>
+    [116; 134) 'A::<i1...x: 1 }': A<i128>
+    [131; 132) '1': i128
+    [140; 142) 'a3': A<i128>
+    [140; 144) 'a3.x': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    A(42);
+    A(42u128);
+    Some("x");
+    Option::Some("x");
+    None;
+    let x: Option<i64> = None;
+}
+"#),
+        @r###"
+    [76; 184) '{     ...one; }': ()
+    [82; 83) 'A': A<i32>(T) -> A<T>
+    [82; 87) 'A(42)': A<i32>
+    [84; 86) '42': i32
+    [93; 94) 'A': A<u128>(T) -> A<T>
+    [93; 102) 'A(42u128)': A<u128>
+    [95; 101) '42u128': u128
+    [108; 112) 'Some': Some<&str>(T) -> Option<T>
+    [108; 117) 'Some("x")': Option<&str>
+    [113; 116) '"x"': &str
+    [123; 135) 'Option::Some': Some<&str>(T) -> Option<T>
+    [123; 140) 'Option...e("x")': Option<&str>
+    [136; 139) '"x"': &str
+    [146; 150) 'None': Option<{unknown}>
+    [160; 161) 'x': Option<i64>
+    [177; 181) 'None': Option<i64>
+    "###
+    );
+}
+
+#[test]
+fn infer_function_generics() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(t: T) -> T { t }
+
+fn test() {
+    id(1u32);
+    id::<i128>(1);
+    let x: u64 = id(1);
+}
+"#),
+        @r###"
+    [10; 11) 't': T
+    [21; 26) '{ t }': T
+    [23; 24) 't': T
+    [38; 98) '{     ...(1); }': ()
+    [44; 46) 'id': fn id<u32>(T) -> T
+    [44; 52) 'id(1u32)': u32
+    [47; 51) '1u32': u32
+    [58; 68) 'id::<i128>': fn id<i128>(T) -> T
+    [58; 71) 'id::<i128>(1)': i128
+    [69; 70) '1': i128
+    [81; 82) 'x': u64
+    [90; 92) 'id': fn id<u64>(T) -> T
+    [90; 95) 'id(1)': u64
+    [93; 94) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T1, T2> {
+    x: T1,
+    y: T2,
+}
+impl<Y, X> A<X, Y> {
+    fn x(self) -> X {
+        self.x
+    }
+    fn y(self) -> Y {
+        self.y
+    }
+    fn z<T>(self, t: T) -> (X, Y, T) {
+        (self.x, self.y, t)
+    }
+}
+
+fn test() -> i128 {
+    let a = A { x: 1u64, y: 1i64 };
+    a.x();
+    a.y();
+    a.z(1i128);
+    a.z::<u128>(1);
+}
+"#),
+        @r###"
+    [74; 78) 'self': A<X, Y>
+    [85; 107) '{     ...     }': X
+    [95; 99) 'self': A<X, Y>
+    [95; 101) 'self.x': X
+    [117; 121) 'self': A<X, Y>
+    [128; 150) '{     ...     }': Y
+    [138; 142) 'self': A<X, Y>
+    [138; 144) 'self.y': Y
+    [163; 167) 'self': A<X, Y>
+    [169; 170) 't': T
+    [188; 223) '{     ...     }': (X, Y, T)
+    [198; 217) '(self.....y, t)': (X, Y, T)
+    [199; 203) 'self': A<X, Y>
+    [199; 205) 'self.x': X
+    [207; 211) 'self': A<X, Y>
+    [207; 213) 'self.y': Y
+    [215; 216) 't': T
+    [245; 342) '{     ...(1); }': ()
+    [255; 256) 'a': A<u64, i64>
+    [259; 281) 'A { x:...1i64 }': A<u64, i64>
+    [266; 270) '1u64': u64
+    [275; 279) '1i64': i64
+    [287; 288) 'a': A<u64, i64>
+    [287; 292) 'a.x()': u64
+    [298; 299) 'a': A<u64, i64>
+    [298; 303) 'a.y()': i64
+    [309; 310) 'a': A<u64, i64>
+    [309; 319) 'a.z(1i128)': (u64, i64, i128)
+    [313; 318) '1i128': i128
+    [325; 326) 'a': A<u64, i64>
+    [325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
+    [337; 338) '1': u128
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics_with_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> {
+    Some(T),
+    None,
+}
+impl<T> Option<T> {
+    fn as_ref(&self) -> Option<&T> {}
+}
+fn test(o: Option<u32>) {
+    (&o).as_ref();
+    o.as_ref();
+}
+"#),
+        @r###"
+    [78; 82) 'self': &Option<T>
+    [98; 100) '{}': ()
+    [111; 112) 'o': Option<u32>
+    [127; 165) '{     ...f(); }': ()
+    [133; 146) '(&o).as_ref()': Option<&u32>
+    [134; 136) '&o': &Option<u32>
+    [135; 136) 'o': Option<u32>
+    [152; 153) 'o': Option<u32>
+    [152; 162) 'o.as_ref()': Option<&u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_generic_chain() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+impl<T2> A<T2> {
+    fn x(self) -> T2 {
+        self.x
+    }
+}
+fn id<T>(t: T) -> T { t }
+
+fn test() -> i128 {
+     let x = 1;
+     let y = id(x);
+     let a = A { x: id(y) };
+     let z = id(a.x);
+     let b = A { x: z };
+     b.x()
+}
+"#),
+        @r###"
+    [53; 57) 'self': A<T2>
+    [65; 87) '{     ...     }': T2
+    [75; 79) 'self': A<T2>
+    [75; 81) 'self.x': T2
+    [99; 100) 't': T
+    [110; 115) '{ t }': T
+    [112; 113) 't': T
+    [135; 261) '{     ....x() }': i128
+    [146; 147) 'x': i128
+    [150; 151) '1': i128
+    [162; 163) 'y': i128
+    [166; 168) 'id': fn id<i128>(T) -> T
+    [166; 171) 'id(x)': i128
+    [169; 170) 'x': i128
+    [182; 183) 'a': A<i128>
+    [186; 200) 'A { x: id(y) }': A<i128>
+    [193; 195) 'id': fn id<i128>(T) -> T
+    [193; 198) 'id(y)': i128
+    [196; 197) 'y': i128
+    [211; 212) 'z': i128
+    [215; 217) 'id': fn id<i128>(T) -> T
+    [215; 222) 'id(a.x)': i128
+    [218; 219) 'a': A<i128>
+    [218; 221) 'a.x': i128
+    [233; 234) 'b': A<i128>
+    [237; 247) 'A { x: z }': A<i128>
+    [244; 245) 'z': i128
+    [254; 255) 'b': A<i128>
+    [254; 259) 'b.x()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Struct;
+
+impl Struct {
+    const FOO: u32 = 1;
+}
+
+enum Enum {}
+
+impl Enum {
+    const BAR: u32 = 2;
+}
+
+trait Trait {
+    const ID: u32;
+}
+
+struct TraitTest;
+
+impl Trait for TraitTest {
+    const ID: u32 = 5;
+}
+
+fn test() {
+    let x = Struct::FOO;
+    let y = Enum::BAR;
+    let z = TraitTest::ID;
+}
+"#),
+        @r###"
+    [52; 53) '1': u32
+    [105; 106) '2': u32
+    [213; 214) '5': u32
+    [229; 307) '{     ...:ID; }': ()
+    [239; 240) 'x': u32
+    [243; 254) 'Struct::FOO': u32
+    [264; 265) 'y': u32
+    [268; 277) 'Enum::BAR': u32
+    [287; 288) 'z': u32
+    [291; 304) 'TraitTest::ID': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X, Y> { x: X, y: Y }
+type Foo = A<u32, i128>;
+type Bar<T> = A<T, u128>;
+type Baz<U, V> = A<V, U>;
+fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
+    x.x;
+    x.y;
+    y.x;
+    y.y;
+    z.x;
+    z.y;
+}
+"#),
+        @r###"
+    [116; 117) 'x': A<u32, i128>
+    [124; 125) 'y': A<&str, u128>
+    [138; 139) 'z': A<u8, i8>
+    [154; 211) '{     ...z.y; }': ()
+    [160; 161) 'x': A<u32, i128>
+    [160; 163) 'x.x': u32
+    [169; 170) 'x': A<u32, i128>
+    [169; 172) 'x.y': i128
+    [178; 179) 'y': A<&str, u128>
+    [178; 181) 'y.x': &str
+    [187; 188) 'y': A<&str, u128>
+    [187; 190) 'y.y': u128
+    [196; 197) 'z': A<u8, i8>
+    [196; 199) 'z.x': u8
+    [205; 206) 'z': A<u8, i8>
+    [205; 208) 'z.y': i8
+    "###
+    )
+}
+
+#[test]
+fn recursive_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X> {}
+type Foo = Foo;
+type Bar = A<Bar>;
+fn test(x: Foo) {}
+"#),
+        @r###"
+    [59; 60) 'x': {unknown}
+    [67; 69) '{}': ()
+    "###
+    )
+}
+
+#[test]
+fn infer_type_param() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(x: T) -> T {
+    x
+}
+
+fn clone<T>(x: &T) -> T {
+    *x
+}
+
+fn test() {
+    let y = 10u32;
+    id(y);
+    let x: bool = clone(z);
+    id::<i128>(1);
+}
+"#),
+        @r###"
+    [10; 11) 'x': T
+    [21; 30) '{     x }': T
+    [27; 28) 'x': T
+    [44; 45) 'x': &T
+    [56; 66) '{     *x }': T
+    [62; 64) '*x': T
+    [63; 64) 'x': &T
+    [78; 158) '{     ...(1); }': ()
+    [88; 89) 'y': u32
+    [92; 97) '10u32': u32
+    [103; 105) 'id': fn id<u32>(T) -> T
+    [103; 108) 'id(y)': u32
+    [106; 107) 'y': u32
+    [118; 119) 'x': bool
+    [128; 133) 'clone': fn clone<bool>(&T) -> T
+    [128; 136) 'clone(z)': bool
+    [134; 135) 'z': &bool
+    [142; 152) 'id::<i128>': fn id<i128>(T) -> T
+    [142; 155) 'id::<i128>(1)': i128
+    [153; 154) '1': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo;
+impl Foo { const ASSOC_CONST: u32 = 0; }
+const GLOBAL_CONST: u32 = 101;
+fn test() {
+    const LOCAL_CONST: u32 = 99;
+    let x = LOCAL_CONST;
+    let z = GLOBAL_CONST;
+    let id = Foo::ASSOC_CONST;
+}
+"#),
+        @r###"
+    [49; 50) '0': u32
+    [80; 83) '101': u32
+    [95; 213) '{     ...NST; }': ()
+    [138; 139) 'x': u32
+    [142; 153) 'LOCAL_CONST': u32
+    [163; 164) 'z': u32
+    [167; 179) 'GLOBAL_CONST': u32
+    [189; 191) 'id': u32
+    [194; 210) 'Foo::A..._CONST': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_static() {
+    assert_snapshot!(
+        infer(r#"
+static GLOBAL_STATIC: u32 = 101;
+static mut GLOBAL_STATIC_MUT: u32 = 101;
+fn test() {
+    static LOCAL_STATIC: u32 = 99;
+    static mut LOCAL_STATIC_MUT: u32 = 99;
+    let x = LOCAL_STATIC;
+    let y = LOCAL_STATIC_MUT;
+    let z = GLOBAL_STATIC;
+    let w = GLOBAL_STATIC_MUT;
+}
+"#),
+        @r###"
+    [29; 32) '101': u32
+    [70; 73) '101': u32
+    [85; 280) '{     ...MUT; }': ()
+    [173; 174) 'x': u32
+    [177; 189) 'LOCAL_STATIC': u32
+    [199; 200) 'y': u32
+    [203; 219) 'LOCAL_...IC_MUT': u32
+    [229; 230) 'z': u32
+    [233; 246) 'GLOBAL_STATIC': u32
+    [256; 257) 'w': u32
+    [260; 277) 'GLOBAL...IC_MUT': u32
+    "###
+    );
+}
+
+#[test]
+fn shadowing_primitive() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct i32;
+struct Foo;
+
+impl i32 { fn foo(&self) -> Foo { Foo } }
+
+fn main() {
+    let x: i32 = i32;
+    x.foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "Foo");
+}
+
+#[test]
+fn not_shadowing_primitive_by_module() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() {}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn not_shadowing_module_by_primitive() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() -> u32 {0}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    str::foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn closure_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || -> usize { return 1; };
+}
+"#),
+        @r###"
+    [17; 59) '{     ...; }; }': ()
+    [27; 28) 'x': || -> usize
+    [31; 56) '|| -> ...n 1; }': || -> usize
+    [43; 56) '{ return 1; }': !
+    [45; 53) 'return 1': !
+    [52; 53) '1': usize
+    "###
+    );
+}
+
+#[test]
+fn closure_return_unit() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || { return; };
+}
+"#),
+        @r###"
+    [17; 48) '{     ...; }; }': ()
+    [27; 28) 'x': || -> ()
+    [31; 45) '|| { return; }': || -> ()
+    [34; 45) '{ return; }': !
+    [36; 42) 'return': !
+    "###
+    );
+}
+
+#[test]
+fn closure_return_inferred() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || { "test" };
+}
+"#),
+        @r###"
+    [17; 47) '{     ..." }; }': ()
+    [27; 28) 'x': || -> &str
+    [31; 44) '|| { "test" }': || -> &str
+    [34; 44) '{ "test" }': &str
+    [36; 42) '"test"': &str
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
new file mode 100644
index 000000000..ae316922b
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -0,0 +1,1598 @@
+use insta::assert_snapshot;
+
+use ra_db::fixture::WithFixture;
+use test_utils::covers;
+
+use super::{infer, infer_with_mismatches, type_at, type_at_pos};
+use crate::test_db::TestDB;
+
+#[test]
+fn infer_await() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct IntFuture;
+
+impl Future for IntFuture {
+    type Output = u64;
+}
+
+fn test() {
+    let r = IntFuture;
+    let v = r.await;
+    v<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use future::*;
+mod future {
+    trait Future {
+        type Output;
+    }
+}
+
+"#,
+    );
+    assert_eq!("u64", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_try() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let r: Result<i32, u64> = Result::Ok(1);
+    let v = r?;
+    v<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    trait Try {
+        type Ok;
+        type Error;
+    }
+}
+
+#[prelude_import] use result::*;
+mod result {
+    enum Result<O, E> {
+        Ok(O),
+        Err(E)
+    }
+
+    impl<O, E> crate::ops::Try for Result<O, E> {
+        type Ok = O;
+        type Error = E;
+    }
+}
+
+"#,
+    );
+    assert_eq!("i32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_for_loop() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+use std::collections::Vec;
+
+fn test() {
+    let v = Vec::new();
+    v.push("foo");
+    for x in v {
+        x<|>;
+    }
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+}
+
+mod collections {
+    struct Vec<T> {}
+    impl<T> Vec<T> {
+        fn new() -> Self { Vec {} }
+        fn push(&mut self, t: T) { }
+    }
+
+    impl<T> crate::iter::IntoIterator for Vec<T> {
+        type Item=T;
+    }
+}
+"#,
+    );
+    assert_eq!("&str", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ops_neg() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Neg for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = -a;
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Neg {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ops_not() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Not for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = !a;
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Not {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_from_bound_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<T: Trait<u32>>(t: T) {}
+fn test() {
+    let s = S(unknown);
+    foo(s);
+}
+"#),
+        @r###"
+    [86; 87) 't': T
+    [92; 94) '{}': ()
+    [105; 144) '{     ...(s); }': ()
+    [115; 116) 's': S<u32>
+    [119; 120) 'S': S<u32>(T) -> S<T>
+    [119; 129) 'S(unknown)': S<u32>
+    [121; 128) 'unknown': u32
+    [135; 138) 'foo': fn foo<S<u32>>(T) -> ()
+    [135; 141) 'foo(s)': ()
+    [139; 140) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_from_bound_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<U, T: Trait<U>>(t: T) -> U {}
+fn test() {
+    let s = S(unknown);
+    let x: u32 = foo(s);
+}
+"#),
+        @r###"
+    [87; 88) 't': T
+    [98; 100) '{}': ()
+    [111; 163) '{     ...(s); }': ()
+    [121; 122) 's': S<u32>
+    [125; 126) 'S': S<u32>(T) -> S<T>
+    [125; 135) 'S(unknown)': S<u32>
+    [127; 134) 'unknown': u32
+    [145; 146) 'x': u32
+    [154; 157) 'foo': fn foo<u32, S<u32>>(T) -> U
+    [154; 160) 'foo(s)': u32
+    [158; 159) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_project_associated_type() {
+    // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn test<T: Iterable>() {
+    let x: <S as Iterable>::Item = 1;
+    let y: <T as Iterable>::Item = no_matter;
+    let z: T::Item = no_matter;
+    let a: <T>::Item = no_matter;
+}
+"#),
+        @r###"
+    [108; 261) '{     ...ter; }': ()
+    [118; 119) 'x': u32
+    [145; 146) '1': u32
+    [156; 157) 'y': {unknown}
+    [183; 192) 'no_matter': {unknown}
+    [202; 203) 'z': {unknown}
+    [215; 224) 'no_matter': {unknown}
+    [234; 235) 'a': {unknown}
+    [249; 258) 'no_matter': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_return_associated_type() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn foo1<T: Iterable>(t: T) -> T::Item {}
+fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
+fn foo3<T: Iterable>(t: T) -> <T>::Item {}
+fn test() {
+    let x = foo1(S);
+    let y = foo2(S);
+    let z = foo3(S);
+}
+"#),
+        @r###"
+    [106; 107) 't': T
+    [123; 125) '{}': ()
+    [147; 148) 't': T
+    [178; 180) '{}': ()
+    [202; 203) 't': T
+    [221; 223) '{}': ()
+    [234; 300) '{     ...(S); }': ()
+    [244; 245) 'x': u32
+    [248; 252) 'foo1': fn foo1<S>(T) -> <T as Iterable>::Item
+    [248; 255) 'foo1(S)': u32
+    [253; 254) 'S': S
+    [265; 266) 'y': u32
+    [269; 273) 'foo2': fn foo2<S>(T) -> <T as Iterable>::Item
+    [269; 276) 'foo2(S)': u32
+    [274; 275) 'S': S
+    [286; 287) 'z': u32
+    [290; 294) 'foo3': fn foo3<S>(T) -> <T as Iterable>::Item
+    [290; 297) 'foo3(S)': u32
+    [295; 296) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_type_bound() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+fn test<T: Iterable<Item=u32>>() {
+    let y: T::Item = unknown;
+}
+"#),
+        @r###"
+    [67; 100) '{     ...own; }': ()
+    [77; 78) 'y': {unknown}
+    [90; 97) 'unknown': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_const_body() {
+    assert_snapshot!(
+        infer(r#"
+const A: u32 = 1 + 1;
+static B: u64 = { let x = 1; x };
+"#),
+        @r###"
+    [16; 17) '1': u32
+    [16; 21) '1 + 1': u32
+    [20; 21) '1': u32
+    [39; 55) '{ let ...1; x }': u64
+    [45; 46) 'x': u64
+    [49; 50) '1': u64
+    [52; 53) 'x': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_fields() {
+    assert_snapshot!(
+        infer(r#"
+struct S(i32, u64);
+fn test() -> u64 {
+    let a = S(4, 6);
+    let b = a.0;
+    a.1
+}
+"#),
+        @r###"
+    [38; 87) '{     ... a.1 }': u64
+    [48; 49) 'a': S
+    [52; 53) 'S': S(i32, u64) -> S
+    [52; 59) 'S(4, 6)': S
+    [54; 55) '4': i32
+    [57; 58) '6': u64
+    [69; 70) 'b': i32
+    [73; 74) 'a': S
+    [73; 76) 'a.0': i32
+    [82; 83) 'a': S
+    [82; 85) 'a.1': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_with_fn() {
+    assert_snapshot!(
+        infer(r#"
+struct S(fn(u32) -> u64);
+fn test() -> u64 {
+    let a = S(|i| 2*i);
+    let b = a.0(4);
+    a.0(2)
+}
+"#),
+        @r###"
+    [44; 102) '{     ...0(2) }': u64
+    [54; 55) 'a': S
+    [58; 59) 'S': S(fn(u32) -> u64) -> S
+    [58; 68) 'S(|i| 2*i)': S
+    [60; 67) '|i| 2*i': |u32| -> u64
+    [61; 62) 'i': u32
+    [64; 65) '2': u32
+    [64; 67) '2*i': u32
+    [66; 67) 'i': u32
+    [78; 79) 'b': u64
+    [82; 83) 'a': S
+    [82; 85) 'a.0': fn(u32) -> u64
+    [82; 88) 'a.0(4)': u64
+    [86; 87) '4': u32
+    [94; 95) 'a': S
+    [94; 97) 'a.0': fn(u32) -> u64
+    [94; 100) 'a.0(2)': u64
+    [98; 99) '2': u32
+    "###
+    );
+}
+
+#[test]
+fn indexing_arrays() {
+    assert_snapshot!(
+        infer("fn main() { &mut [9][2]; }"),
+        @r###"
+    [10; 26) '{ &mut...[2]; }': ()
+    [12; 23) '&mut [9][2]': &mut {unknown}
+    [17; 20) '[9]': [i32;_]
+    [17; 23) '[9][2]': {unknown}
+    [18; 19) '9': i32
+    [21; 22) '2': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_ops_index() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Index<u32> for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = a[1];
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Index<Idx> {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn deref_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn deref_trait_with_inference_var() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+fn new_arc<T>() -> Arc<T> {}
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+fn foo(a: Arc<S>) {}
+
+fn test() {
+    let a = new_arc();
+    let b = (*a)<|>;
+    foo(a);
+}
+"#,
+    );
+    assert_eq!(t, "S");
+}
+
+#[test]
+fn deref_trait_infinite_recursion() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct S;
+
+impl Deref for S {
+    type Target = S;
+}
+
+fn test(s: S) {
+    s.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn deref_trait_with_question_mark_size() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn obligation_from_function_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<u32> for S {}
+
+fn foo<T: Trait<U>, U>(t: T) -> U {}
+
+fn test(s: S) {
+    foo(s)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn obligation_from_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<isize> for S {}
+
+struct O;
+impl O {
+    fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
+}
+
+fn test() {
+    O.foo(S)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "isize");
+}
+
+#[test]
+fn obligation_from_self_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<i64> for S {}
+
+impl S {
+    fn foo<U>(&self) -> U where Self: Trait<U> {}
+}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "i64");
+}
+
+#[test]
+fn obligation_from_impl_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<&str> for S {}
+
+struct O<T>;
+impl<U, T: Trait<U>> O<T> {
+    fn foo(&self) -> U {}
+}
+
+fn test(o: O<S>) {
+    o.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn generic_param_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T: Clone>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_1_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T: Trait>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_2_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_deref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+}
+trait Trait {}
+impl<T> Deref for T where T: Trait {
+    type Target = i128;
+}
+fn test<T: Trait>(t: T) { (*t)<|>; }
+"#,
+    );
+    assert_eq!(t, "i128");
+}
+
+#[test]
+fn associated_type_placeholder() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+
+pub struct RefMutL<T>;
+
+impl<T> ApplyL for RefMutL<T> {
+    type Out = <T as ApplyL>::Out;
+}
+
+fn test<T: ApplyL>() {
+    let y: <RefMutL<T> as ApplyL>::Out = no_matter;
+    y<|>;
+}
+"#,
+    );
+    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
+    // FIXME: fix type parameter names going missing when going through Chalk
+    assert_eq!(t, "ApplyL::Out<[missing name]>");
+}
+
+#[test]
+fn associated_type_placeholder_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
+
+fn test<T: ApplyL>(t: T) {
+    let y = foo(t);
+    y<|>;
+}
+"#,
+    );
+    // FIXME here Chalk doesn't normalize the type to a placeholder. I think we
+    // need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
+    // to the trait env ourselves here; probably Chalk can't do this by itself.
+    // assert_eq!(t, "ApplyL::Out<[missing name]>");
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn impl_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> impl Trait<u64> {}
+
+fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [99; 101) '{}': ()
+    [111; 112) 'x': impl Trait<u64>
+    [131; 132) 'y': &impl Trait<u64>
+    [152; 269) '{     ...2(); }': ()
+    [158; 159) 'x': impl Trait<u64>
+    [165; 166) 'y': &impl Trait<u64>
+    [176; 177) 'z': impl Trait<u64>
+    [180; 183) 'bar': fn bar() -> impl Trait<u64>
+    [180; 185) 'bar()': impl Trait<u64>
+    [191; 192) 'x': impl Trait<u64>
+    [191; 198) 'x.foo()': u64
+    [204; 205) 'y': &impl Trait<u64>
+    [204; 211) 'y.foo()': u64
+    [217; 218) 'z': impl Trait<u64>
+    [217; 224) 'z.foo()': u64
+    [230; 231) 'x': impl Trait<u64>
+    [230; 238) 'x.foo2()': i64
+    [244; 245) 'y': &impl Trait<u64>
+    [244; 252) 'y.foo2()': i64
+    [258; 259) 'z': impl Trait<u64>
+    [258; 266) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> dyn Trait<u64> {}
+
+fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [98; 100) '{}': ()
+    [110; 111) 'x': dyn Trait<u64>
+    [129; 130) 'y': &dyn Trait<u64>
+    [149; 266) '{     ...2(); }': ()
+    [155; 156) 'x': dyn Trait<u64>
+    [162; 163) 'y': &dyn Trait<u64>
+    [173; 174) 'z': dyn Trait<u64>
+    [177; 180) 'bar': fn bar() -> dyn Trait<u64>
+    [177; 182) 'bar()': dyn Trait<u64>
+    [188; 189) 'x': dyn Trait<u64>
+    [188; 195) 'x.foo()': u64
+    [201; 202) 'y': &dyn Trait<u64>
+    [201; 208) 'y.foo()': u64
+    [214; 215) 'z': dyn Trait<u64>
+    [214; 221) 'z.foo()': u64
+    [227; 228) 'x': dyn Trait<u64>
+    [227; 235) 'x.foo2()': i64
+    [241; 242) 'y': &dyn Trait<u64>
+    [241; 249) 'y.foo2()': i64
+    [255; 256) 'z': dyn Trait<u64>
+    [255; 263) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait_bare() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn foo(&self) -> u64;
+}
+fn bar() -> Trait {}
+
+fn test(x: Trait, y: &Trait) -> u64 {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+}
+"#),
+        @r###"
+    [27; 31) 'self': &Self
+    [61; 63) '{}': ()
+    [73; 74) 'x': dyn Trait
+    [83; 84) 'y': &dyn Trait
+    [101; 176) '{     ...o(); }': ()
+    [107; 108) 'x': dyn Trait
+    [114; 115) 'y': &dyn Trait
+    [125; 126) 'z': dyn Trait
+    [129; 132) 'bar': fn bar() -> dyn Trait
+    [129; 134) 'bar()': dyn Trait
+    [140; 141) 'x': dyn Trait
+    [140; 147) 'x.foo()': u64
+    [153; 154) 'y': &dyn Trait
+    [153; 160) 'y.foo()': u64
+    [166; 167) 'z': dyn Trait
+    [166; 173) 'z.foo()': u64
+    "###
+    );
+}
+
+#[test]
+fn weird_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {}
+fn test() {
+    let a: impl Trait + 'lifetime = foo;
+    let b: impl 'lifetime = foo;
+    let b: impl (Trait) = foo;
+    let b: impl ('lifetime) = foo;
+    let d: impl ?Sized = foo;
+    let e: impl Trait + ?Sized = foo;
+}
+"#),
+        @r###"
+    [26; 237) '{     ...foo; }': ()
+    [36; 37) 'a': impl Trait + {error}
+    [64; 67) 'foo': impl Trait + {error}
+    [77; 78) 'b': impl {error}
+    [97; 100) 'foo': impl {error}
+    [110; 111) 'b': impl Trait
+    [128; 131) 'foo': impl Trait
+    [141; 142) 'b': impl {error}
+    [163; 166) 'foo': impl {error}
+    [176; 177) 'd': impl {error}
+    [193; 196) 'foo': impl {error}
+    [206; 207) 'e': impl Trait + {error}
+    [231; 234) 'foo': impl Trait + {error}
+    "###
+    );
+}
+
+#[test]
+fn error_bound_chalk() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    fn foo(&self) -> u32 {}
+}
+
+fn test(x: (impl Trait + UnknownTrait)) {
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn assoc_type_bindings() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    type Type;
+}
+
+fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> Trait for S<T> { type Type = T; }
+
+fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
+    get(x);
+    get2(x);
+    get(y);
+    get2(y);
+    get(set(S));
+    get2(set(S));
+    get2(S::<str>);
+}
+"#),
+        @r###"
+    [50; 51) 't': T
+    [78; 80) '{}': ()
+    [112; 113) 't': T
+    [123; 125) '{}': ()
+    [155; 156) 't': T
+    [166; 169) '{t}': T
+    [167; 168) 't': T
+    [257; 258) 'x': T
+    [263; 264) 'y': impl Trait<Type = i64>
+    [290; 398) '{     ...r>); }': ()
+    [296; 299) 'get': fn get<T>(T) -> <T as Trait>::Type
+    [296; 302) 'get(x)': {unknown}
+    [300; 301) 'x': T
+    [308; 312) 'get2': fn get2<{unknown}, T>(T) -> U
+    [308; 315) 'get2(x)': {unknown}
+    [313; 314) 'x': T
+    [321; 324) 'get': fn get<impl Trait<Type = i64>>(T) -> <T as Trait>::Type
+    [321; 327) 'get(y)': {unknown}
+    [325; 326) 'y': impl Trait<Type = i64>
+    [333; 337) 'get2': fn get2<{unknown}, impl Trait<Type = i64>>(T) -> U
+    [333; 340) 'get2(y)': {unknown}
+    [338; 339) 'y': impl Trait<Type = i64>
+    [346; 349) 'get': fn get<S<u64>>(T) -> <T as Trait>::Type
+    [346; 357) 'get(set(S))': u64
+    [350; 353) 'set': fn set<S<u64>>(T) -> T
+    [350; 356) 'set(S)': S<u64>
+    [354; 355) 'S': S<u64>
+    [363; 367) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [363; 375) 'get2(set(S))': u64
+    [368; 371) 'set': fn set<S<u64>>(T) -> T
+    [368; 374) 'set(S)': S<u64>
+    [372; 373) 'S': S<u64>
+    [381; 385) 'get2': fn get2<str, S<str>>(T) -> U
+    [381; 395) 'get2(S::<str>)': str
+    [386; 394) 'S::<str>': S<str>
+    "###
+    );
+}
+
+#[test]
+fn impl_trait_assoc_binding_projection_bug() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+pub trait Language {
+    type Kind;
+}
+pub enum RustLanguage {}
+impl Language for RustLanguage {
+    type Kind = SyntaxKind;
+}
+struct SyntaxNode<L> {}
+fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
+
+trait Clone {
+    fn clone(&self) -> Self;
+}
+
+fn api_walkthrough() {
+    for node in foo() {
+        node.clone()<|>;
+    }
+}
+
+//- /std.rs crate:std
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+    trait Iterator {
+        type Item;
+    }
+    impl<T: Iterator> IntoIterator for T {
+        type Item = <T as Iterator>::Item;
+    }
+}
+"#,
+    );
+    assert_eq!("{unknown}", type_at_pos(&db, pos));
+}
+
+#[test]
+fn projection_eq_within_chalk() {
+    // std::env::set_var("CHALK_DEBUG", "1");
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    type Type;
+}
+trait Trait2<T> {
+    fn foo(self) -> T;
+}
+impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
+
+fn test<T: Trait1<Type = u32>>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [62; 66) 'self': Self
+    [164; 165) 'x': T
+    [170; 186) '{     ...o(); }': ()
+    [176; 177) 'x': T
+    [176; 183) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn where_clause_trait_in_scope_for_method_resolution() {
+    let t = type_at(
+        r#"
+//- /main.rs
+mod foo {
+    trait Trait {
+        fn foo(&self) -> u32 {}
+    }
+}
+
+fn test<T: foo::Trait>(x: T) {
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn super_trait_method_resolution() {
+    assert_snapshot!(
+        infer(r#"
+mod foo {
+    trait SuperTrait {
+        fn foo(&self) -> u32 {}
+    }
+}
+trait Trait1: foo::SuperTrait {}
+trait Trait2 where Self: foo::SuperTrait {}
+
+fn test<T: Trait1, U: Trait2>(x: T, y: U) {
+    x.foo();
+    y.foo();
+}
+"#),
+        @r###"
+    [50; 54) 'self': &Self
+    [63; 65) '{}': ()
+    [182; 183) 'x': T
+    [188; 189) 'y': U
+    [194; 223) '{     ...o(); }': ()
+    [200; 201) 'x': T
+    [200; 207) 'x.foo()': u32
+    [213; 214) 'y': U
+    [213; 220) 'y.foo()': u32
+    "###
+    );
+}
+
+#[test]
+fn super_trait_cycle() {
+    // This just needs to not crash
+    assert_snapshot!(
+        infer(r#"
+trait A: B {}
+trait B: A {}
+
+fn test<T: A>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [44; 45) 'x': T
+    [50; 66) '{     ...o(); }': ()
+    [56; 57) 'x': T
+    [56; 63) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn super_trait_assoc_type_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait SuperTrait { type Type; }
+trait Trait where Self: SuperTrait {}
+
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> SuperTrait for S<T> { type Type = T; }
+impl<T> Trait for S<T> {}
+
+fn test() {
+    get2(set(S));
+}
+"#),
+        @r###"
+    [103; 104) 't': T
+    [114; 116) '{}': ()
+    [146; 147) 't': T
+    [157; 160) '{t}': T
+    [158; 159) 't': T
+    [259; 280) '{     ...S)); }': ()
+    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [265; 277) 'get2(set(S))': u64
+    [270; 273) 'set': fn set<S<u64>>(T) -> T
+    [270; 276) 'set(S)': S<u64>
+    [274; 275) 'S': S<u64>
+    "###
+    );
+}
+
+#[test]
+fn fn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+
+    fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
+}
+
+fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
+    f.call_once((1, 2));
+}
+"#),
+        @r###"
+    [57; 61) 'self': Self
+    [63; 67) 'args': Args
+    [150; 151) 'f': F
+    [156; 184) '{     ...2)); }': ()
+    [162; 163) 'f': F
+    [162; 181) 'f.call...1, 2))': {unknown}
+    [174; 180) '(1, 2)': (u32, u64)
+    [175; 176) '1': u32
+    [178; 179) '2': u64
+    "###
+    );
+}
+
+#[test]
+fn closure_1() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+enum Option<T> { Some(T), None }
+impl<T> Option<T> {
+    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
+}
+
+fn test() {
+    let x = Option::Some(1u32);
+    x.map(|v| v + 1);
+    x.map(|_v| 1u64);
+    let y: Option<i64> = x.map(|_v| 1);
+}
+"#),
+        @r###"
+    [148; 152) 'self': Option<T>
+    [154; 155) 'f': F
+    [173; 175) '{}': ()
+    [189; 308) '{     ... 1); }': ()
+    [199; 200) 'x': Option<u32>
+    [203; 215) 'Option::Some': Some<u32>(T) -> Option<T>
+    [203; 221) 'Option...(1u32)': Option<u32>
+    [216; 220) '1u32': u32
+    [227; 228) 'x': Option<u32>
+    [227; 243) 'x.map(...v + 1)': Option<u32>
+    [233; 242) '|v| v + 1': |u32| -> u32
+    [234; 235) 'v': u32
+    [237; 238) 'v': u32
+    [237; 242) 'v + 1': u32
+    [241; 242) '1': u32
+    [249; 250) 'x': Option<u32>
+    [249; 265) 'x.map(... 1u64)': Option<u64>
+    [255; 264) '|_v| 1u64': |u32| -> u64
+    [256; 258) '_v': u32
+    [260; 264) '1u64': u64
+    [275; 276) 'y': Option<i64>
+    [292; 293) 'x': Option<u32>
+    [292; 305) 'x.map(|_v| 1)': Option<i64>
+    [298; 304) '|_v| 1': |u32| -> i64
+    [299; 301) '_v': u32
+    [303; 304) '1': i64
+    "###
+    );
+}
+
+#[test]
+fn closure_2() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn test<F: FnOnce(u32) -> u64>(f: F) {
+    f(1);
+    let g = |v| v + 1;
+    g(1u64);
+    let h = |v| 1u128 + v;
+}
+"#),
+        @r###"
+    [73; 74) 'f': F
+    [79; 155) '{     ...+ v; }': ()
+    [85; 86) 'f': F
+    [85; 89) 'f(1)': {unknown}
+    [87; 88) '1': i32
+    [99; 100) 'g': |u64| -> i32
+    [103; 112) '|v| v + 1': |u64| -> i32
+    [104; 105) 'v': u64
+    [107; 108) 'v': u64
+    [107; 112) 'v + 1': i32
+    [111; 112) '1': i32
+    [118; 119) 'g': |u64| -> i32
+    [118; 125) 'g(1u64)': i32
+    [120; 124) '1u64': u64
+    [135; 136) 'h': |u128| -> u128
+    [139; 152) '|v| 1u128 + v': |u128| -> u128
+    [140; 141) 'v': u128
+    [143; 148) '1u128': u128
+    [143; 152) '1u128 + v': u128
+    [151; 152) 'v': u128
+    "###
+    );
+}
+
+#[test]
+fn closure_as_argument_inference_order() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
+fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
+
+struct S;
+impl S {
+    fn method(self) -> u64;
+
+    fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
+    fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
+}
+
+fn test() {
+    let x1 = foo1(S, |s| s.method());
+    let x2 = foo2(|s| s.method(), S);
+    let x3 = S.foo1(S, |s| s.method());
+    let x4 = S.foo2(|s| s.method(), S);
+}
+"#),
+        @r###"
+    [95; 96) 'x': T
+    [101; 102) 'f': F
+    [112; 114) '{}': ()
+    [148; 149) 'f': F
+    [154; 155) 'x': T
+    [165; 167) '{}': ()
+    [202; 206) 'self': S
+    [254; 258) 'self': S
+    [260; 261) 'x': T
+    [266; 267) 'f': F
+    [277; 279) '{}': ()
+    [317; 321) 'self': S
+    [323; 324) 'f': F
+    [329; 330) 'x': T
+    [340; 342) '{}': ()
+    [356; 515) '{     ... S); }': ()
+    [366; 368) 'x1': u64
+    [371; 375) 'foo1': fn foo1<S, u64, |S| -> u64>(T, F) -> U
+    [371; 394) 'foo1(S...hod())': u64
+    [376; 377) 'S': S
+    [379; 393) '|s| s.method()': |S| -> u64
+    [380; 381) 's': S
+    [383; 384) 's': S
+    [383; 393) 's.method()': u64
+    [404; 406) 'x2': u64
+    [409; 413) 'foo2': fn foo2<S, u64, |S| -> u64>(F, T) -> U
+    [409; 432) 'foo2(|...(), S)': u64
+    [414; 428) '|s| s.method()': |S| -> u64
+    [415; 416) 's': S
+    [418; 419) 's': S
+    [418; 428) 's.method()': u64
+    [430; 431) 'S': S
+    [442; 444) 'x3': u64
+    [447; 448) 'S': S
+    [447; 472) 'S.foo1...hod())': u64
+    [454; 455) 'S': S
+    [457; 471) '|s| s.method()': |S| -> u64
+    [458; 459) 's': S
+    [461; 462) 's': S
+    [461; 471) 's.method()': u64
+    [482; 484) 'x4': u64
+    [487; 488) 'S': S
+    [487; 512) 'S.foo2...(), S)': u64
+    [494; 508) '|s| s.method()': |S| -> u64
+    [495; 496) 's': S
+    [498; 499) 's': S
+    [498; 508) 's.method()': u64
+    [510; 511) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn unselected_projection_in_trait_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T: Trait>() where T::Item: Trait2 {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn trait_impl_self_ty() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+   fn foo(&self);
+}
+
+struct S;
+
+impl Trait<Self> for S {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn trait_impl_self_ty_cycle() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+   fn foo(&self);
+}
+
+struct S<T>;
+
+impl Trait for S<Self> {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2<T> {}
+
+fn test<T: Trait>() where T: Trait2<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unify_impl_trait() {
+    covers!(insert_vars_for_impl_trait);
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+trait Trait<T> {}
+
+fn foo(x: impl Trait<u32>) { loop {} }
+fn bar<T>(x: impl Trait<T>) -> T { loop {} }
+
+struct S<T>(T);
+impl<T> Trait<T> for S<T> {}
+
+fn default<T>() -> T { loop {} }
+
+fn test() -> impl Trait<i32> {
+    let s1 = S(default());
+    foo(s1);
+    let x: i32 = bar(S(default()));
+    S(default())
+}
+"#, true),
+        @r###"
+    [27; 28) 'x': impl Trait<u32>
+    [47; 58) '{ loop {} }': ()
+    [49; 56) 'loop {}': !
+    [54; 56) '{}': ()
+    [69; 70) 'x': impl Trait<T>
+    [92; 103) '{ loop {} }': T
+    [94; 101) 'loop {}': !
+    [99; 101) '{}': ()
+    [172; 183) '{ loop {} }': T
+    [174; 181) 'loop {}': !
+    [179; 181) '{}': ()
+    [214; 310) '{     ...t()) }': S<i32>
+    [224; 226) 's1': S<u32>
+    [229; 230) 'S': S<u32>(T) -> S<T>
+    [229; 241) 'S(default())': S<u32>
+    [231; 238) 'default': fn default<u32>() -> T
+    [231; 240) 'default()': u32
+    [247; 250) 'foo': fn foo(impl Trait<u32>) -> ()
+    [247; 254) 'foo(s1)': ()
+    [251; 253) 's1': S<u32>
+    [264; 265) 'x': i32
+    [273; 276) 'bar': fn bar<i32>(impl Trait<T>) -> T
+    [273; 290) 'bar(S(...lt()))': i32
+    [277; 278) 'S': S<i32>(T) -> S<T>
+    [277; 289) 'S(default())': S<i32>
+    [279; 286) 'default': fn default<i32>() -> T
+    [279; 288) 'default()': i32
+    [296; 297) 'S': S<i32>(T) -> S<T>
+    [296; 308) 'S(default())': S<i32>
+    [298; 305) 'default': fn default<i32>() -> T
+    [298; 307) 'default()': i32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 76189a60b..c4dc857bc 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -1,7 +1,7 @@
 //! Trait solving using Chalk.
 use std::sync::{Arc, Mutex};
 
-use chalk_ir::{cast::Cast, family::ChalkIr};
+use chalk_ir::cast::Cast;
 use hir_def::{expr::ExprId, DefWithBodyId, ImplId, TraitId, TypeAliasId};
 use log::debug;
 use ra_db::{impl_intern_key, salsa, CrateId};
@@ -12,14 +12,15 @@ use crate::db::HirDatabase;
 
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
 
-use self::chalk::{from_chalk, ToChalk};
+use self::chalk::{from_chalk, ToChalk, TypeFamily};
 
 pub(crate) mod chalk;
+mod builtin;
 
 #[derive(Debug, Clone)]
 pub struct TraitSolver {
     krate: CrateId,
-    inner: Arc<Mutex<chalk_solve::Solver<ChalkIr>>>,
+    inner: Arc<Mutex<chalk_solve::Solver<TypeFamily>>>,
 }
 
 /// We need eq for salsa
@@ -35,8 +36,8 @@ impl TraitSolver {
     fn solve(
         &self,
         db: &impl HirDatabase,
-        goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal<ChalkIr>>>,
-    ) -> Option<chalk_solve::Solution<ChalkIr>> {
+        goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal<TypeFamily>>>,
+    ) -> Option<chalk_solve::Solution<TypeFamily>> {
         let context = ChalkContext { db, krate: self.krate };
         debug!("solve goal: {:?}", goal);
         let mut solver = match self.inner.lock() {
@@ -200,17 +201,17 @@ pub(crate) fn trait_solve_query(
 
 fn solution_from_chalk(
     db: &impl HirDatabase,
-    solution: chalk_solve::Solution<ChalkIr>,
+    solution: chalk_solve::Solution<TypeFamily>,
 ) -> Solution {
-    let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<ChalkIr>>| {
+    let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<TypeFamily>>| {
         let value = subst
             .value
             .parameters
             .into_iter()
             .map(|p| {
-                let ty = match p {
-                    chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
-                    chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
+                let ty = match p.ty() {
+                    Some(ty) => from_chalk(db, ty.clone()),
+                    None => unimplemented!(),
                 };
                 ty
             })
@@ -290,7 +291,7 @@ impl FnTrait {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ClosureFnTraitImplData {
     def: DefWithBodyId,
     expr: ExprId,
@@ -299,7 +300,7 @@ pub struct ClosureFnTraitImplData {
 
 /// An impl. Usually this comes from an impl block, but some built-in types get
 /// synthetic impls.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Impl {
     /// A normal impl from an impl block.
     ImplBlock(ImplId),
diff --git a/crates/ra_hir_ty/src/traits/builtin.rs b/crates/ra_hir_ty/src/traits/builtin.rs
new file mode 100644
index 000000000..dd41176f0
--- /dev/null
+++ b/crates/ra_hir_ty/src/traits/builtin.rs
@@ -0,0 +1,178 @@
+//! This module provides the built-in trait implementations, e.g. to make
+//! closures implement `Fn`.
+use hir_def::{expr::Expr, lang_item::LangItemTarget, TraitId, TypeAliasId};
+use hir_expand::name::name;
+use ra_db::CrateId;
+
+use super::{AssocTyValue, Impl};
+use crate::{db::HirDatabase, ApplicationTy, Substs, TraitRef, Ty, TypeCtor};
+
+pub(super) struct BuiltinImplData {
+    pub num_vars: usize,
+    pub trait_ref: TraitRef,
+    pub where_clauses: Vec<super::GenericPredicate>,
+    pub assoc_ty_values: Vec<AssocTyValue>,
+}
+
+pub(super) struct BuiltinImplAssocTyValueData {
+    pub impl_: Impl,
+    pub assoc_ty_id: TypeAliasId,
+    pub num_vars: usize,
+    pub value: Ty,
+}
+
+pub(super) fn get_builtin_impls(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    ty: &Ty,
+    trait_: TraitId,
+    mut callback: impl FnMut(Impl),
+) {
+    // Note: since impl_datum needs to be infallible, we need to make sure here
+    // that we have all prerequisites to build the respective impls.
+    if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Closure { def, expr }, .. }) = ty {
+        for &fn_trait in [super::FnTrait::FnOnce, super::FnTrait::FnMut, super::FnTrait::Fn].iter()
+        {
+            if let Some(actual_trait) = get_fn_trait(db, krate, fn_trait) {
+                if trait_ == actual_trait {
+                    let impl_ = super::ClosureFnTraitImplData { def: *def, expr: *expr, fn_trait };
+                    if check_closure_fn_trait_impl_prerequisites(db, krate, impl_) {
+                        callback(Impl::ClosureFnTraitImpl(impl_));
+                    }
+                }
+            }
+        }
+    }
+}
+
+pub(super) fn impl_datum(db: &impl HirDatabase, krate: CrateId, impl_: Impl) -> BuiltinImplData {
+    match impl_ {
+        Impl::ImplBlock(_) => unreachable!(),
+        Impl::ClosureFnTraitImpl(data) => closure_fn_trait_impl_datum(db, krate, data),
+    }
+}
+
+pub(super) fn associated_ty_value(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: AssocTyValue,
+) -> BuiltinImplAssocTyValueData {
+    match data {
+        AssocTyValue::TypeAlias(_) => unreachable!(),
+        AssocTyValue::ClosureFnTraitImplOutput(data) => {
+            closure_fn_trait_output_assoc_ty_value(db, krate, data)
+        }
+    }
+}
+
+fn check_closure_fn_trait_impl_prerequisites(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> bool {
+    // the respective Fn/FnOnce/FnMut trait needs to exist
+    if get_fn_trait(db, krate, data.fn_trait).is_none() {
+        return false;
+    }
+
+    // FIXME: there are more assumptions that we should probably check here:
+    // the traits having no type params, FnOnce being a supertrait
+
+    // the FnOnce trait needs to exist and have an assoc type named Output
+    let fn_once_trait = match get_fn_trait(db, krate, super::FnTrait::FnOnce) {
+        Some(t) => t,
+        None => return false,
+    };
+    db.trait_data(fn_once_trait).associated_type_by_name(&name![Output]).is_some()
+}
+
+fn closure_fn_trait_impl_datum(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> BuiltinImplData {
+    // for some closure |X, Y| -> Z:
+    // impl<T, U, V> Fn<(T, U)> for closure<fn(T, U) -> V> { Output = V }
+
+    let trait_ = get_fn_trait(db, krate, data.fn_trait) // get corresponding fn trait
+        // the existence of the Fn trait has been checked before
+        .expect("fn trait for closure impl missing");
+
+    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
+        Expr::Lambda { args, .. } => args.len() as u16,
+        _ => {
+            log::warn!("closure for closure type {:?} not found", data);
+            0
+        }
+    };
+
+    let arg_ty = Ty::apply(
+        TypeCtor::Tuple { cardinality: num_args },
+        Substs::builder(num_args as usize).fill_with_bound_vars(0).build(),
+    );
+    let sig_ty = Ty::apply(
+        TypeCtor::FnPtr { num_args },
+        Substs::builder(num_args as usize + 1).fill_with_bound_vars(0).build(),
+    );
+
+    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
+
+    let trait_ref = TraitRef {
+        trait_: trait_.into(),
+        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
+    };
+
+    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data.clone());
+
+    BuiltinImplData {
+        num_vars: num_args as usize + 1,
+        trait_ref,
+        where_clauses: Vec::new(),
+        assoc_ty_values: vec![output_ty_id],
+    }
+}
+
+fn closure_fn_trait_output_assoc_ty_value(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> BuiltinImplAssocTyValueData {
+    let impl_ = Impl::ClosureFnTraitImpl(data.clone());
+
+    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
+        Expr::Lambda { args, .. } => args.len() as u16,
+        _ => {
+            log::warn!("closure for closure type {:?} not found", data);
+            0
+        }
+    };
+
+    let output_ty = Ty::Bound(num_args.into());
+
+    let fn_once_trait =
+        get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
+
+    let output_ty_id = db
+        .trait_data(fn_once_trait)
+        .associated_type_by_name(&name![Output])
+        .expect("assoc ty value should not exist");
+
+    BuiltinImplAssocTyValueData {
+        impl_,
+        assoc_ty_id: output_ty_id,
+        num_vars: num_args as usize + 1,
+        value: output_ty,
+    }
+}
+
+fn get_fn_trait(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    fn_trait: super::FnTrait,
+) -> Option<TraitId> {
+    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
+    match target {
+        LangItemTarget::TraitId(t) => Some(t),
+        _ => None,
+    }
+}
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 35de37e6b..555930c9b 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -1,32 +1,99 @@
 //! Conversion code from/to Chalk.
-use std::sync::Arc;
+use std::{fmt, sync::Arc};
 
 use log::debug;
 
-use chalk_ir::{
-    cast::Cast, family::ChalkIr, Identifier, Parameter, PlaceholderIndex, TypeId, TypeKindId,
-    TypeName, UniverseIndex,
-};
-use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
-use ra_db::CrateId;
+use chalk_ir::{cast::Cast, Parameter, PlaceholderIndex, TypeName, UniverseIndex};
 
-use hir_def::{
-    expr::Expr, lang_item::LangItemTarget, AssocItemId, AstItemDef, ContainerId, GenericDefId,
-    ImplId, Lookup, TraitId, TypeAliasId,
+use hir_def::{AssocContainerId, AssocItemId, GenericDefId, HasModule, Lookup, TypeAliasId};
+use ra_db::{
+    salsa::{InternId, InternKey},
+    CrateId,
 };
-use hir_expand::name;
-
-use ra_db::salsa::{InternId, InternKey};
 
-use super::{AssocTyValue, Canonical, ChalkContext, Impl, Obligation};
+use super::{builtin, AssocTyValue, Canonical, ChalkContext, Impl, Obligation};
 use crate::{
-    db::HirDatabase, display::HirDisplay, ApplicationTy, GenericPredicate, ImplTy, ProjectionTy,
-    Substs, TraitRef, Ty, TypeCtor, TypeWalk,
+    db::HirDatabase, display::HirDisplay, utils::generics, ApplicationTy, GenericPredicate,
+    ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
-/// This represents a trait whose name we could not resolve.
-const UNKNOWN_TRAIT: chalk_ir::TraitId =
-    chalk_ir::TraitId(chalk_ir::RawId { index: u32::max_value() });
+#[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
+pub struct TypeFamily {}
+
+impl chalk_ir::family::TypeFamily for TypeFamily {
+    type InternedType = Box<chalk_ir::TyData<Self>>;
+    type InternedLifetime = chalk_ir::LifetimeData<Self>;
+    type InternedParameter = chalk_ir::ParameterData<Self>;
+    type DefId = InternId;
+
+    // FIXME: implement these
+    fn debug_struct_id(
+        _type_kind_id: chalk_ir::StructId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_trait_id(
+        _type_kind_id: chalk_ir::TraitId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_assoc_type_id(
+        _id: chalk_ir::AssocTypeId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_projection(
+        _projection: &chalk_ir::ProjectionTy<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn intern_ty(ty: chalk_ir::TyData<Self>) -> Box<chalk_ir::TyData<Self>> {
+        Box::new(ty)
+    }
+
+    fn ty_data(ty: &Box<chalk_ir::TyData<Self>>) -> &chalk_ir::TyData<Self> {
+        ty
+    }
+
+    fn intern_lifetime(lifetime: chalk_ir::LifetimeData<Self>) -> chalk_ir::LifetimeData<Self> {
+        lifetime
+    }
+
+    fn lifetime_data(lifetime: &chalk_ir::LifetimeData<Self>) -> &chalk_ir::LifetimeData<Self> {
+        lifetime
+    }
+
+    fn intern_parameter(parameter: chalk_ir::ParameterData<Self>) -> chalk_ir::ParameterData<Self> {
+        parameter
+    }
+
+    fn parameter_data(parameter: &chalk_ir::ParameterData<Self>) -> &chalk_ir::ParameterData<Self> {
+        parameter
+    }
+}
+
+impl chalk_ir::family::HasTypeFamily for TypeFamily {
+    type TypeFamily = Self;
+}
+
+pub type AssocTypeId = chalk_ir::AssocTypeId<TypeFamily>;
+pub type AssociatedTyDatum = chalk_rust_ir::AssociatedTyDatum<TypeFamily>;
+pub type TraitId = chalk_ir::TraitId<TypeFamily>;
+pub type TraitDatum = chalk_rust_ir::TraitDatum<TypeFamily>;
+pub type StructId = chalk_ir::StructId<TypeFamily>;
+pub type StructDatum = chalk_rust_ir::StructDatum<TypeFamily>;
+pub type ImplId = chalk_ir::ImplId<TypeFamily>;
+pub type ImplDatum = chalk_rust_ir::ImplDatum<TypeFamily>;
+pub type AssociatedTyValueId = chalk_rust_ir::AssociatedTyValueId;
+pub type AssociatedTyValue = chalk_rust_ir::AssociatedTyValue<TypeFamily>;
 
 pub(super) trait ToChalk {
     type Chalk;
@@ -42,21 +109,11 @@ where
 }
 
 impl ToChalk for Ty {
-    type Chalk = chalk_ir::Ty<ChalkIr>;
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty<ChalkIr> {
+    type Chalk = chalk_ir::Ty<TypeFamily>;
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty<TypeFamily> {
         match self {
             Ty::Apply(apply_ty) => {
-                let name = match apply_ty.ctor {
-                    TypeCtor::AssociatedType(type_alias) => {
-                        let type_id = type_alias.to_chalk(db);
-                        TypeName::AssociatedType(type_id)
-                    }
-                    _ => {
-                        // other TypeCtors get interned and turned into a chalk StructId
-                        let struct_id = apply_ty.ctor.to_chalk(db);
-                        TypeName::TypeKindId(struct_id.into())
-                    }
-                };
+                let name = apply_ty.ctor.to_chalk(db);
                 let parameters = apply_ty.parameters.to_chalk(db);
                 chalk_ir::ApplicationTy { name, parameters }.cast().intern()
             }
@@ -66,17 +123,30 @@ impl ToChalk for Ty {
                 chalk_ir::ProjectionTy { associated_ty_id, parameters }.cast().intern()
             }
             Ty::Param { idx, .. } => {
-                PlaceholderIndex { ui: UniverseIndex::ROOT, idx: idx as usize }.to_ty::<ChalkIr>()
+                PlaceholderIndex { ui: UniverseIndex::ROOT, idx: idx as usize }
+                    .to_ty::<TypeFamily>()
             }
             Ty::Bound(idx) => chalk_ir::TyData::BoundVar(idx as usize).intern(),
             Ty::Infer(_infer_ty) => panic!("uncanonicalized infer ty"),
             Ty::Dyn(predicates) => {
-                let where_clauses = predicates.iter().cloned().map(|p| p.to_chalk(db)).collect();
-                chalk_ir::TyData::Dyn(make_binders(where_clauses, 1)).intern()
+                let where_clauses = predicates
+                    .iter()
+                    .filter(|p| !p.is_error())
+                    .cloned()
+                    .map(|p| p.to_chalk(db))
+                    .collect();
+                let bounded_ty = chalk_ir::BoundedTy { bounds: make_binders(where_clauses, 1) };
+                chalk_ir::TyData::Dyn(bounded_ty).intern()
             }
             Ty::Opaque(predicates) => {
-                let where_clauses = predicates.iter().cloned().map(|p| p.to_chalk(db)).collect();
-                chalk_ir::TyData::Opaque(make_binders(where_clauses, 1)).intern()
+                let where_clauses = predicates
+                    .iter()
+                    .filter(|p| !p.is_error())
+                    .cloned()
+                    .map(|p| p.to_chalk(db))
+                    .collect();
+                let bounded_ty = chalk_ir::BoundedTy { bounds: make_binders(where_clauses, 1) };
+                chalk_ir::TyData::Opaque(bounded_ty).intern()
             }
             Ty::Unknown => {
                 let parameters = Vec::new();
@@ -85,30 +155,19 @@ impl ToChalk for Ty {
             }
         }
     }
-    fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty<ChalkIr>) -> Self {
+    fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty<TypeFamily>) -> Self {
         match chalk.data().clone() {
-            chalk_ir::TyData::Apply(apply_ty) => {
-                // FIXME this is kind of hacky due to the fact that
-                // TypeName::Placeholder is a Ty::Param on our side
-                match apply_ty.name {
-                    TypeName::TypeKindId(TypeKindId::StructId(struct_id)) => {
-                        let ctor = from_chalk(db, struct_id);
-                        let parameters = from_chalk(db, apply_ty.parameters);
-                        Ty::Apply(ApplicationTy { ctor, parameters })
-                    }
-                    TypeName::AssociatedType(type_id) => {
-                        let ctor = TypeCtor::AssociatedType(from_chalk(db, type_id));
-                        let parameters = from_chalk(db, apply_ty.parameters);
-                        Ty::Apply(ApplicationTy { ctor, parameters })
-                    }
-                    TypeName::Error => Ty::Unknown,
-                    // FIXME handle TypeKindId::Trait/Type here
-                    TypeName::TypeKindId(_) => unimplemented!(),
-                    TypeName::Placeholder(idx) => {
-                        assert_eq!(idx.ui, UniverseIndex::ROOT);
-                        Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }
-                    }
+            chalk_ir::TyData::Apply(apply_ty) => match apply_ty.name {
+                TypeName::Error => Ty::Unknown,
+                _ => {
+                    let ctor = from_chalk(db, apply_ty.name);
+                    let parameters = from_chalk(db, apply_ty.parameters);
+                    Ty::Apply(ApplicationTy { ctor, parameters })
                 }
+            },
+            chalk_ir::TyData::Placeholder(idx) => {
+                assert_eq!(idx.ui, UniverseIndex::ROOT);
+                Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }
             }
             chalk_ir::TyData::Projection(proj) => {
                 let associated_ty = from_chalk(db, proj.associated_ty_id);
@@ -119,15 +178,15 @@ impl ToChalk for Ty {
             chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx as u32),
             chalk_ir::TyData::InferenceVar(_iv) => Ty::Unknown,
             chalk_ir::TyData::Dyn(where_clauses) => {
-                assert_eq!(where_clauses.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(), 1);
                 let predicates =
-                    where_clauses.value.into_iter().map(|c| from_chalk(db, c)).collect();
+                    where_clauses.bounds.value.into_iter().map(|c| from_chalk(db, c)).collect();
                 Ty::Dyn(predicates)
             }
             chalk_ir::TyData::Opaque(where_clauses) => {
-                assert_eq!(where_clauses.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(), 1);
                 let predicates =
-                    where_clauses.value.into_iter().map(|c| from_chalk(db, c)).collect();
+                    where_clauses.bounds.value.into_iter().map(|c| from_chalk(db, c)).collect();
                 Ty::Opaque(predicates)
             }
         }
@@ -135,18 +194,21 @@ impl ToChalk for Ty {
 }
 
 impl ToChalk for Substs {
-    type Chalk = Vec<chalk_ir::Parameter<ChalkIr>>;
+    type Chalk = Vec<chalk_ir::Parameter<TypeFamily>>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> Vec<Parameter<ChalkIr>> {
+    fn to_chalk(self, db: &impl HirDatabase) -> Vec<Parameter<TypeFamily>> {
         self.iter().map(|ty| ty.clone().to_chalk(db).cast()).collect()
     }
 
-    fn from_chalk(db: &impl HirDatabase, parameters: Vec<chalk_ir::Parameter<ChalkIr>>) -> Substs {
+    fn from_chalk(
+        db: &impl HirDatabase,
+        parameters: Vec<chalk_ir::Parameter<TypeFamily>>,
+    ) -> Substs {
         let tys = parameters
             .into_iter()
-            .map(|p| match p {
-                chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
-                chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
+            .map(|p| match p.ty() {
+                Some(ty) => from_chalk(db, ty.clone()),
+                None => unimplemented!(),
             })
             .collect();
         Substs(tys)
@@ -154,88 +216,102 @@ impl ToChalk for Substs {
 }
 
 impl ToChalk for TraitRef {
-    type Chalk = chalk_ir::TraitRef<ChalkIr>;
+    type Chalk = chalk_ir::TraitRef<TypeFamily>;
 
-    fn to_chalk(self: TraitRef, db: &impl HirDatabase) -> chalk_ir::TraitRef<ChalkIr> {
+    fn to_chalk(self: TraitRef, db: &impl HirDatabase) -> chalk_ir::TraitRef<TypeFamily> {
         let trait_id = self.trait_.to_chalk(db);
         let parameters = self.substs.to_chalk(db);
         chalk_ir::TraitRef { trait_id, parameters }
     }
 
-    fn from_chalk(db: &impl HirDatabase, trait_ref: chalk_ir::TraitRef<ChalkIr>) -> Self {
+    fn from_chalk(db: &impl HirDatabase, trait_ref: chalk_ir::TraitRef<TypeFamily>) -> Self {
         let trait_ = from_chalk(db, trait_ref.trait_id);
         let substs = from_chalk(db, trait_ref.parameters);
         TraitRef { trait_, substs }
     }
 }
 
-impl ToChalk for TraitId {
-    type Chalk = chalk_ir::TraitId;
+impl ToChalk for hir_def::TraitId {
+    type Chalk = TraitId;
 
-    fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TraitId {
-        chalk_ir::TraitId(id_to_chalk(self))
+    fn to_chalk(self, _db: &impl HirDatabase) -> TraitId {
+        chalk_ir::TraitId(self.as_intern_id())
     }
 
-    fn from_chalk(_db: &impl HirDatabase, trait_id: chalk_ir::TraitId) -> TraitId {
-        id_from_chalk(trait_id.0)
+    fn from_chalk(_db: &impl HirDatabase, trait_id: TraitId) -> hir_def::TraitId {
+        InternKey::from_intern_id(trait_id.0)
     }
 }
 
 impl ToChalk for TypeCtor {
-    type Chalk = chalk_ir::StructId;
+    type Chalk = TypeName<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::StructId {
-        db.intern_type_ctor(self).into()
+    fn to_chalk(self, db: &impl HirDatabase) -> TypeName<TypeFamily> {
+        match self {
+            TypeCtor::AssociatedType(type_alias) => {
+                let type_id = type_alias.to_chalk(db);
+                TypeName::AssociatedType(type_id)
+            }
+            _ => {
+                // other TypeCtors get interned and turned into a chalk StructId
+                let struct_id = db.intern_type_ctor(self).into();
+                TypeName::Struct(struct_id)
+            }
+        }
     }
 
-    fn from_chalk(db: &impl HirDatabase, struct_id: chalk_ir::StructId) -> TypeCtor {
-        db.lookup_intern_type_ctor(struct_id.into())
+    fn from_chalk(db: &impl HirDatabase, type_name: TypeName<TypeFamily>) -> TypeCtor {
+        match type_name {
+            TypeName::Struct(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
+            TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
+            TypeName::Error => {
+                // this should not be reached, since we don't represent TypeName::Error with TypeCtor
+                unreachable!()
+            }
+        }
     }
 }
 
 impl ToChalk for Impl {
-    type Chalk = chalk_ir::ImplId;
+    type Chalk = ImplId;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ImplId {
+    fn to_chalk(self, db: &impl HirDatabase) -> ImplId {
         db.intern_chalk_impl(self).into()
     }
 
-    fn from_chalk(db: &impl HirDatabase, impl_id: chalk_ir::ImplId) -> Impl {
+    fn from_chalk(db: &impl HirDatabase, impl_id: ImplId) -> Impl {
         db.lookup_intern_chalk_impl(impl_id.into())
     }
 }
 
 impl ToChalk for TypeAliasId {
-    type Chalk = chalk_ir::TypeId;
+    type Chalk = AssocTypeId;
 
-    fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TypeId {
-        chalk_ir::TypeId(id_to_chalk(self))
+    fn to_chalk(self, _db: &impl HirDatabase) -> AssocTypeId {
+        chalk_ir::AssocTypeId(self.as_intern_id())
     }
 
-    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAliasId {
-        id_from_chalk(type_alias_id.0)
+    fn from_chalk(_db: &impl HirDatabase, type_alias_id: AssocTypeId) -> TypeAliasId {
+        InternKey::from_intern_id(type_alias_id.0)
     }
 }
 
 impl ToChalk for AssocTyValue {
-    type Chalk = chalk_rust_ir::AssociatedTyValueId;
+    type Chalk = AssociatedTyValueId;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_rust_ir::AssociatedTyValueId {
+    fn to_chalk(self, db: &impl HirDatabase) -> AssociatedTyValueId {
         db.intern_assoc_ty_value(self).into()
     }
 
-    fn from_chalk(
-        db: &impl HirDatabase,
-        assoc_ty_value_id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> AssocTyValue {
+    fn from_chalk(db: &impl HirDatabase, assoc_ty_value_id: AssociatedTyValueId) -> AssocTyValue {
         db.lookup_intern_assoc_ty_value(assoc_ty_value_id.into())
     }
 }
 
 impl ToChalk for GenericPredicate {
-    type Chalk = chalk_ir::QuantifiedWhereClause<ChalkIr>;
+    type Chalk = chalk_ir::QuantifiedWhereClause<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::QuantifiedWhereClause<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::QuantifiedWhereClause<TypeFamily> {
         match self {
             GenericPredicate::Implemented(trait_ref) => {
                 make_binders(chalk_ir::WhereClause::Implemented(trait_ref.to_chalk(db)), 0)
@@ -247,26 +323,16 @@ impl ToChalk for GenericPredicate {
                 }),
                 0,
             ),
-            GenericPredicate::Error => {
-                let impossible_trait_ref = chalk_ir::TraitRef {
-                    trait_id: UNKNOWN_TRAIT,
-                    parameters: vec![Ty::Unknown.to_chalk(db).cast()],
-                };
-                make_binders(chalk_ir::WhereClause::Implemented(impossible_trait_ref), 0)
-            }
+            GenericPredicate::Error => panic!("tried passing GenericPredicate::Error to Chalk"),
         }
     }
 
     fn from_chalk(
         db: &impl HirDatabase,
-        where_clause: chalk_ir::QuantifiedWhereClause<ChalkIr>,
+        where_clause: chalk_ir::QuantifiedWhereClause<TypeFamily>,
     ) -> GenericPredicate {
         match where_clause.value {
             chalk_ir::WhereClause::Implemented(tr) => {
-                if tr.trait_id == UNKNOWN_TRAIT {
-                    // FIXME we need an Error enum on the Chalk side to avoid this
-                    return GenericPredicate::Error;
-                }
                 GenericPredicate::Implemented(from_chalk(db, tr))
             }
             chalk_ir::WhereClause::ProjectionEq(projection_eq) => {
@@ -279,9 +345,9 @@ impl ToChalk for GenericPredicate {
 }
 
 impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::ProjectionTy<ChalkIr>;
+    type Chalk = chalk_ir::ProjectionTy<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ProjectionTy<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ProjectionTy<TypeFamily> {
         chalk_ir::ProjectionTy {
             associated_ty_id: self.associated_ty.to_chalk(db),
             parameters: self.parameters.to_chalk(db),
@@ -290,7 +356,7 @@ impl ToChalk for ProjectionTy {
 
     fn from_chalk(
         db: &impl HirDatabase,
-        projection_ty: chalk_ir::ProjectionTy<ChalkIr>,
+        projection_ty: chalk_ir::ProjectionTy<TypeFamily>,
     ) -> ProjectionTy {
         ProjectionTy {
             associated_ty: from_chalk(db, projection_ty.associated_ty_id),
@@ -300,31 +366,31 @@ impl ToChalk for ProjectionTy {
 }
 
 impl ToChalk for super::ProjectionPredicate {
-    type Chalk = chalk_ir::Normalize<ChalkIr>;
+    type Chalk = chalk_ir::Normalize<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Normalize<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Normalize<TypeFamily> {
         chalk_ir::Normalize {
             projection: self.projection_ty.to_chalk(db),
             ty: self.ty.to_chalk(db),
         }
     }
 
-    fn from_chalk(_db: &impl HirDatabase, _normalize: chalk_ir::Normalize<ChalkIr>) -> Self {
+    fn from_chalk(_db: &impl HirDatabase, _normalize: chalk_ir::Normalize<TypeFamily>) -> Self {
         unimplemented!()
     }
 }
 
 impl ToChalk for Obligation {
-    type Chalk = chalk_ir::DomainGoal<ChalkIr>;
+    type Chalk = chalk_ir::DomainGoal<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::DomainGoal<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::DomainGoal<TypeFamily> {
         match self {
             Obligation::Trait(tr) => tr.to_chalk(db).cast(),
             Obligation::Projection(pr) => pr.to_chalk(db).cast(),
         }
     }
 
-    fn from_chalk(_db: &impl HirDatabase, _goal: chalk_ir::DomainGoal<ChalkIr>) -> Self {
+    fn from_chalk(_db: &impl HirDatabase, _goal: chalk_ir::DomainGoal<TypeFamily>) -> Self {
         unimplemented!()
     }
 }
@@ -348,16 +414,17 @@ where
 }
 
 impl ToChalk for Arc<super::TraitEnvironment> {
-    type Chalk = chalk_ir::Environment<ChalkIr>;
+    type Chalk = chalk_ir::Environment<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Environment<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Environment<TypeFamily> {
         let mut clauses = Vec::new();
         for pred in &self.predicates {
             if pred.is_error() {
                 // for env, we just ignore errors
                 continue;
             }
-            let program_clause: chalk_ir::ProgramClause<ChalkIr> = pred.clone().to_chalk(db).cast();
+            let program_clause: chalk_ir::ProgramClause<TypeFamily> =
+                pred.clone().to_chalk(db).cast();
             clauses.push(program_clause.into_from_env_clause());
         }
         chalk_ir::Environment::new().add_clauses(clauses)
@@ -365,7 +432,7 @@ impl ToChalk for Arc<super::TraitEnvironment> {
 
     fn from_chalk(
         _db: &impl HirDatabase,
-        _env: chalk_ir::Environment<ChalkIr>,
+        _env: chalk_ir::Environment<TypeFamily>,
     ) -> Arc<super::TraitEnvironment> {
         unimplemented!()
     }
@@ -373,7 +440,7 @@ impl ToChalk for Arc<super::TraitEnvironment> {
 
 impl<T: ToChalk> ToChalk for super::InEnvironment<T>
 where
-    T::Chalk: chalk_ir::family::HasTypeFamily<TypeFamily = ChalkIr>,
+    T::Chalk: chalk_ir::family::HasTypeFamily<TypeFamily = TypeFamily>,
 {
     type Chalk = chalk_ir::InEnvironment<T::Chalk>;
 
@@ -395,6 +462,51 @@ where
     }
 }
 
+impl ToChalk for builtin::BuiltinImplData {
+    type Chalk = ImplDatum;
+
+    fn to_chalk(self, db: &impl HirDatabase) -> ImplDatum {
+        let impl_type = chalk_rust_ir::ImplType::External;
+        let where_clauses = self.where_clauses.into_iter().map(|w| w.to_chalk(db)).collect();
+
+        let impl_datum_bound =
+            chalk_rust_ir::ImplDatumBound { trait_ref: self.trait_ref.to_chalk(db), where_clauses };
+        let associated_ty_value_ids =
+            self.assoc_ty_values.into_iter().map(|v| v.to_chalk(db)).collect();
+        chalk_rust_ir::ImplDatum {
+            binders: make_binders(impl_datum_bound, self.num_vars),
+            impl_type,
+            polarity: chalk_rust_ir::Polarity::Positive,
+            associated_ty_value_ids,
+        }
+    }
+
+    fn from_chalk(_db: &impl HirDatabase, _data: ImplDatum) -> Self {
+        unimplemented!()
+    }
+}
+
+impl ToChalk for builtin::BuiltinImplAssocTyValueData {
+    type Chalk = AssociatedTyValue;
+
+    fn to_chalk(self, db: &impl HirDatabase) -> AssociatedTyValue {
+        let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: self.value.to_chalk(db) };
+
+        chalk_rust_ir::AssociatedTyValue {
+            associated_ty_id: self.assoc_ty_id.to_chalk(db),
+            impl_id: self.impl_.to_chalk(db),
+            value: make_binders(value_bound, self.num_vars),
+        }
+    }
+
+    fn from_chalk(
+        _db: &impl HirDatabase,
+        _data: AssociatedTyValue,
+    ) -> builtin::BuiltinImplAssocTyValueData {
+        unimplemented!()
+    }
+}
+
 fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
     chalk_ir::Binders {
         value,
@@ -406,46 +518,46 @@ fn convert_where_clauses(
     db: &impl HirDatabase,
     def: GenericDefId,
     substs: &Substs,
-) -> Vec<chalk_ir::QuantifiedWhereClause<ChalkIr>> {
+) -> Vec<chalk_ir::QuantifiedWhereClause<TypeFamily>> {
     let generic_predicates = db.generic_predicates(def);
     let mut result = Vec::with_capacity(generic_predicates.len());
     for pred in generic_predicates.iter() {
         if pred.is_error() {
-            // HACK: Return just the single predicate (which is always false
-            // anyway), otherwise Chalk can easily get into slow situations
-            return vec![pred.clone().subst(substs).to_chalk(db)];
+            // skip errored predicates completely
+            continue;
         }
         result.push(pred.clone().subst(substs).to_chalk(db));
     }
     result
 }
 
-impl<'a, DB> chalk_solve::RustIrDatabase<ChalkIr> for ChalkContext<'a, DB>
+impl<'a, DB> chalk_solve::RustIrDatabase<TypeFamily> for ChalkContext<'a, DB>
 where
     DB: HirDatabase,
 {
-    fn associated_ty_data(&self, id: TypeId) -> Arc<AssociatedTyDatum<ChalkIr>> {
+    fn associated_ty_data(&self, id: AssocTypeId) -> Arc<AssociatedTyDatum> {
         self.db.associated_ty_data(id)
     }
-    fn trait_datum(&self, trait_id: chalk_ir::TraitId) -> Arc<TraitDatum<ChalkIr>> {
+    fn trait_datum(&self, trait_id: TraitId) -> Arc<TraitDatum> {
         self.db.trait_datum(self.krate, trait_id)
     }
-    fn struct_datum(&self, struct_id: chalk_ir::StructId) -> Arc<StructDatum<ChalkIr>> {
+    fn struct_datum(&self, struct_id: StructId) -> Arc<StructDatum> {
         self.db.struct_datum(self.krate, struct_id)
     }
-    fn impl_datum(&self, impl_id: chalk_ir::ImplId) -> Arc<ImplDatum<ChalkIr>> {
+    fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum> {
         self.db.impl_datum(self.krate, impl_id)
     }
     fn impls_for_trait(
         &self,
-        trait_id: chalk_ir::TraitId,
-        parameters: &[Parameter<ChalkIr>],
-    ) -> Vec<chalk_ir::ImplId> {
+        trait_id: TraitId,
+        parameters: &[Parameter<TypeFamily>],
+    ) -> Vec<ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
-        if trait_id == UNKNOWN_TRAIT {
-            return Vec::new();
-        }
-        let trait_: TraitId = from_chalk(self.db, trait_id);
+        let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
+
+        // Note: Since we're using impls_for_trait, only impls where the trait
+        // can be resolved should ever reach Chalk. `impl_datum` relies on that
+        // and will panic if the trait can't be resolved.
         let mut result: Vec<_> = self
             .db
             .impls_for_trait(self.krate, trait_.into())
@@ -456,62 +568,47 @@ where
             .collect();
 
         let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref().clone());
-        if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Closure { def, expr }, .. }) = ty {
-            for &fn_trait in
-                [super::FnTrait::FnOnce, super::FnTrait::FnMut, super::FnTrait::Fn].iter()
-            {
-                if let Some(actual_trait) = get_fn_trait(self.db, self.krate, fn_trait) {
-                    if trait_ == actual_trait {
-                        let impl_ = super::ClosureFnTraitImplData { def, expr, fn_trait };
-                        result.push(Impl::ClosureFnTraitImpl(impl_).to_chalk(self.db));
-                    }
-                }
-            }
-        }
+
+        builtin::get_builtin_impls(self.db, self.krate, &ty, trait_, |i| {
+            result.push(i.to_chalk(self.db))
+        });
 
         debug!("impls_for_trait returned {} impls", result.len());
         result
     }
-    fn impl_provided_for(
-        &self,
-        auto_trait_id: chalk_ir::TraitId,
-        struct_id: chalk_ir::StructId,
-    ) -> bool {
+    fn impl_provided_for(&self, auto_trait_id: TraitId, struct_id: StructId) -> bool {
         debug!("impl_provided_for {:?}, {:?}", auto_trait_id, struct_id);
         false // FIXME
     }
-    fn type_name(&self, _id: TypeKindId) -> Identifier {
-        unimplemented!()
-    }
-    fn associated_ty_value(
-        &self,
-        id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> Arc<AssociatedTyValue<ChalkIr>> {
+    fn associated_ty_value(&self, id: AssociatedTyValueId) -> Arc<AssociatedTyValue> {
         self.db.associated_ty_value(self.krate.into(), id)
     }
-    fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<ChalkIr>> {
+    fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<TypeFamily>> {
         vec![]
     }
-    fn local_impls_to_coherence_check(
-        &self,
-        _trait_id: chalk_ir::TraitId,
-    ) -> Vec<chalk_ir::ImplId> {
+    fn local_impls_to_coherence_check(&self, _trait_id: TraitId) -> Vec<ImplId> {
         // We don't do coherence checking (yet)
         unimplemented!()
     }
+    fn as_struct_id(&self, id: &TypeName<TypeFamily>) -> Option<StructId> {
+        match id {
+            TypeName::Struct(struct_id) => Some(*struct_id),
+            _ => None,
+        }
+    }
 }
 
 pub(crate) fn associated_ty_data_query(
     db: &impl HirDatabase,
-    id: TypeId,
-) -> Arc<AssociatedTyDatum<ChalkIr>> {
+    id: AssocTypeId,
+) -> Arc<AssociatedTyDatum> {
     debug!("associated_ty_data {:?}", id);
     let type_alias: TypeAliasId = from_chalk(db, id);
     let trait_ = match type_alias.lookup(db).container {
-        ContainerId::TraitId(t) => t,
+        AssocContainerId::TraitId(t) => t,
         _ => panic!("associated type not in trait"),
     };
-    let generic_params = db.generic_params(type_alias.into());
+    let generic_params = generics(db, type_alias.into());
     let bound_data = chalk_rust_ir::AssociatedTyDatumBound {
         // FIXME add bounds and where clauses
         bounds: vec![],
@@ -521,7 +618,7 @@ pub(crate) fn associated_ty_data_query(
         trait_id: trait_.to_chalk(db),
         id,
         name: lalrpop_intern::intern(&db.type_alias_data(type_alias).name.to_string()),
-        binders: make_binders(bound_data, generic_params.count_params_including_parent()),
+        binders: make_binders(bound_data, generic_params.len()),
     };
     Arc::new(datum)
 }
@@ -529,35 +626,17 @@ pub(crate) fn associated_ty_data_query(
 pub(crate) fn trait_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    trait_id: chalk_ir::TraitId,
-) -> Arc<TraitDatum<ChalkIr>> {
+    trait_id: TraitId,
+) -> Arc<TraitDatum> {
     debug!("trait_datum {:?}", trait_id);
-    if trait_id == UNKNOWN_TRAIT {
-        let trait_datum_bound = chalk_rust_ir::TraitDatumBound { where_clauses: Vec::new() };
-
-        let flags = chalk_rust_ir::TraitFlags {
-            auto: false,
-            marker: false,
-            upstream: true,
-            fundamental: false,
-            non_enumerable: true,
-            coinductive: false,
-        };
-        return Arc::new(TraitDatum {
-            id: trait_id,
-            binders: make_binders(trait_datum_bound, 1),
-            flags,
-            associated_ty_ids: vec![],
-        });
-    }
-    let trait_: TraitId = from_chalk(db, trait_id);
+    let trait_: hir_def::TraitId = from_chalk(db, trait_id);
     let trait_data = db.trait_data(trait_);
     debug!("trait {:?} = {:?}", trait_id, trait_data.name);
-    let generic_params = db.generic_params(trait_.into());
+    let generic_params = generics(db, trait_.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let flags = chalk_rust_ir::TraitFlags {
         auto: trait_data.auto,
-        upstream: trait_.module(db).krate != krate,
+        upstream: trait_.lookup(db).container.module(db).krate != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
         // FIXME set these flags correctly
@@ -580,17 +659,17 @@ pub(crate) fn trait_datum_query(
 pub(crate) fn struct_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    struct_id: chalk_ir::StructId,
-) -> Arc<StructDatum<ChalkIr>> {
+    struct_id: StructId,
+) -> Arc<StructDatum> {
     debug!("struct_datum {:?}", struct_id);
-    let type_ctor: TypeCtor = from_chalk(db, struct_id);
+    let type_ctor: TypeCtor = from_chalk(db, TypeName::Struct(struct_id));
     debug!("struct {:?} = {:?}", struct_id, type_ctor);
     let num_params = type_ctor.num_ty_params(db);
     let upstream = type_ctor.krate(db) != Some(krate);
     let where_clauses = type_ctor
         .as_generic_def()
         .map(|generic_def| {
-            let generic_params = db.generic_params(generic_def.into());
+            let generic_params = generics(db, generic_def.into());
             let bound_vars = Substs::bound_vars(&generic_params);
             convert_where_clauses(db, generic_def, &bound_vars)
         })
@@ -612,35 +691,34 @@ pub(crate) fn struct_datum_query(
 pub(crate) fn impl_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    impl_id: chalk_ir::ImplId,
-) -> Arc<ImplDatum<ChalkIr>> {
+    impl_id: ImplId,
+) -> Arc<ImplDatum> {
     let _p = ra_prof::profile("impl_datum");
     debug!("impl_datum {:?}", impl_id);
     let impl_: Impl = from_chalk(db, impl_id);
     match impl_ {
         Impl::ImplBlock(impl_block) => impl_block_datum(db, krate, impl_id, impl_block),
-        Impl::ClosureFnTraitImpl(data) => closure_fn_trait_impl_datum(db, krate, data),
+        _ => Arc::new(builtin::impl_datum(db, krate, impl_).to_chalk(db)),
     }
-    .unwrap_or_else(invalid_impl_datum)
 }
 
 fn impl_block_datum(
     db: &impl HirDatabase,
     krate: CrateId,
-    chalk_id: chalk_ir::ImplId,
-    impl_id: ImplId,
-) -> Option<Arc<ImplDatum<ChalkIr>>> {
-    let trait_ref = match db.impl_ty(impl_id) {
-        ImplTy::TraitRef(it) => it,
-        ImplTy::Inherent(_) => return None,
-    };
+    chalk_id: ImplId,
+    impl_id: hir_def::ImplId,
+) -> Arc<ImplDatum> {
+    let trait_ref = db
+        .impl_trait(impl_id)
+        // ImplIds for impls where the trait ref can't be resolved should never reach Chalk
+        .expect("invalid impl passed to Chalk");
     let impl_data = db.impl_data(impl_id);
 
-    let generic_params = db.generic_params(impl_id.into());
+    let generic_params = generics(db, impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let trait_ref = trait_ref.subst(&bound_vars);
     let trait_ = trait_ref.trait_;
-    let impl_type = if impl_id.module(db).krate == krate {
+    let impl_type = if impl_id.lookup(db).container.module(db).krate == krate {
         chalk_rust_ir::ImplType::Local
     } else {
         chalk_rust_ir::ImplType::External
@@ -685,94 +763,20 @@ fn impl_block_datum(
         polarity,
         associated_ty_value_ids,
     };
-    Some(Arc::new(impl_datum))
-}
-
-fn invalid_impl_datum() -> Arc<ImplDatum<ChalkIr>> {
-    let trait_ref = chalk_ir::TraitRef {
-        trait_id: UNKNOWN_TRAIT,
-        parameters: vec![chalk_ir::TyData::BoundVar(0).cast().intern().cast()],
-    };
-    let impl_datum_bound = chalk_rust_ir::ImplDatumBound { trait_ref, where_clauses: 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,
-        associated_ty_value_ids: Vec::new(),
-    };
     Arc::new(impl_datum)
 }
 
-fn closure_fn_trait_impl_datum(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> Option<Arc<ImplDatum<ChalkIr>>> {
-    // for some closure |X, Y| -> Z:
-    // impl<T, U, V> Fn<(T, U)> for closure<fn(T, U) -> V> { Output = V }
-
-    let trait_ = get_fn_trait(db, krate, data.fn_trait)?; // get corresponding fn trait
-
-    // validate FnOnce trait, since we need it in the assoc ty value definition
-    // and don't want to return a valid value only to find out later that FnOnce
-    // is broken
-    let fn_once_trait = get_fn_trait(db, krate, super::FnTrait::FnOnce)?;
-    let _output = db.trait_data(fn_once_trait).associated_type_by_name(&name::OUTPUT_TYPE)?;
-
-    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let arg_ty = Ty::apply(
-        TypeCtor::Tuple { cardinality: num_args },
-        Substs::builder(num_args as usize).fill_with_bound_vars(0).build(),
-    );
-    let sig_ty = Ty::apply(
-        TypeCtor::FnPtr { num_args },
-        Substs::builder(num_args as usize + 1).fill_with_bound_vars(0).build(),
-    );
-
-    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
-
-    let trait_ref = TraitRef {
-        trait_: trait_.into(),
-        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
-    };
-
-    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data.clone()).to_chalk(db);
-
-    let impl_type = chalk_rust_ir::ImplType::External;
-
-    let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
-        trait_ref: trait_ref.to_chalk(db),
-        where_clauses: Vec::new(),
-    };
-    let impl_datum = ImplDatum {
-        binders: make_binders(impl_datum_bound, num_args as usize + 1),
-        impl_type,
-        polarity: chalk_rust_ir::Polarity::Positive,
-        associated_ty_value_ids: vec![output_ty_id],
-    };
-    Some(Arc::new(impl_datum))
-}
-
 pub(crate) fn associated_ty_value_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    id: chalk_rust_ir::AssociatedTyValueId,
-) -> Arc<chalk_rust_ir::AssociatedTyValue<ChalkIr>> {
+    id: AssociatedTyValueId,
+) -> Arc<AssociatedTyValue> {
     let data: AssocTyValue = from_chalk(db, id);
     match data {
         AssocTyValue::TypeAlias(type_alias) => {
             type_alias_associated_ty_value(db, krate, type_alias)
         }
-        AssocTyValue::ClosureFnTraitImplOutput(data) => {
-            closure_fn_trait_output_assoc_ty_value(db, krate, data)
-        }
+        _ => Arc::new(builtin::associated_ty_value(db, krate, data).to_chalk(db)),
     }
 }
 
@@ -780,24 +784,20 @@ fn type_alias_associated_ty_value(
     db: &impl HirDatabase,
     _krate: CrateId,
     type_alias: TypeAliasId,
-) -> Arc<AssociatedTyValue<ChalkIr>> {
+) -> Arc<AssociatedTyValue> {
     let type_alias_data = db.type_alias_data(type_alias);
     let impl_id = match type_alias.lookup(db).container {
-        ContainerId::ImplId(it) => it,
+        AssocContainerId::ImplId(it) => it,
         _ => panic!("assoc ty value should be in impl"),
     };
 
-    let trait_ref = match db.impl_ty(impl_id) {
-        ImplTy::TraitRef(it) => it,
-        // we don't return any assoc ty values if the impl'd trait can't be resolved
-        ImplTy::Inherent(_) => panic!("assoc ty value should not exist"),
-    };
+    let trait_ref = db.impl_trait(impl_id).expect("assoc ty value should not exist"); // we don't return any assoc ty values if the impl'd trait can't be resolved
 
     let assoc_ty = db
         .trait_data(trait_ref.trait_)
         .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
-    let generic_params = db.generic_params(impl_id.into());
+    let generic_params = generics(db, impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let ty = db.ty(type_alias.into()).subst(&bound_vars);
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
@@ -809,53 +809,6 @@ fn type_alias_associated_ty_value(
     Arc::new(value)
 }
 
-fn closure_fn_trait_output_assoc_ty_value(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> Arc<AssociatedTyValue<ChalkIr>> {
-    let impl_id = Impl::ClosureFnTraitImpl(data.clone()).to_chalk(db);
-
-    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let output_ty = Ty::Bound(num_args.into());
-
-    let fn_once_trait =
-        get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
-
-    let output_ty_id = db
-        .trait_data(fn_once_trait)
-        .associated_type_by_name(&name::OUTPUT_TYPE)
-        .expect("assoc ty value should not exist");
-
-    let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: output_ty.to_chalk(db) };
-
-    let value = chalk_rust_ir::AssociatedTyValue {
-        associated_ty_id: output_ty_id.to_chalk(db),
-        impl_id,
-        value: make_binders(value_bound, num_args as usize + 1),
-    };
-    Arc::new(value)
-}
-
-fn get_fn_trait(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    fn_trait: super::FnTrait,
-) -> Option<TraitId> {
-    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
-    match target {
-        LangItemTarget::TraitId(t) => Some(t),
-        _ => None,
-    }
-}
-
 fn id_from_chalk<T: InternKey>(chalk_id: chalk_ir::RawId) -> T {
     T::from_intern_id(InternId::from(chalk_id.index))
 }
@@ -863,27 +816,27 @@ fn id_to_chalk<T: InternKey>(salsa_id: T) -> chalk_ir::RawId {
     chalk_ir::RawId { index: salsa_id.as_intern_id().as_u32() }
 }
 
-impl From<chalk_ir::StructId> for crate::TypeCtorId {
-    fn from(struct_id: chalk_ir::StructId) -> Self {
-        id_from_chalk(struct_id.0)
+impl From<StructId> for crate::TypeCtorId {
+    fn from(struct_id: StructId) -> Self {
+        InternKey::from_intern_id(struct_id.0)
     }
 }
 
-impl From<crate::TypeCtorId> for chalk_ir::StructId {
+impl From<crate::TypeCtorId> for StructId {
     fn from(type_ctor_id: crate::TypeCtorId) -> Self {
-        chalk_ir::StructId(id_to_chalk(type_ctor_id))
+        chalk_ir::StructId(type_ctor_id.as_intern_id())
     }
 }
 
-impl From<chalk_ir::ImplId> for crate::traits::GlobalImplId {
-    fn from(impl_id: chalk_ir::ImplId) -> Self {
-        id_from_chalk(impl_id.0)
+impl From<ImplId> for crate::traits::GlobalImplId {
+    fn from(impl_id: ImplId) -> Self {
+        InternKey::from_intern_id(impl_id.0)
     }
 }
 
-impl From<crate::traits::GlobalImplId> for chalk_ir::ImplId {
+impl From<crate::traits::GlobalImplId> for ImplId {
     fn from(impl_id: crate::traits::GlobalImplId) -> Self {
-        chalk_ir::ImplId(id_to_chalk(impl_id))
+        chalk_ir::ImplId(impl_id.as_intern_id())
     }
 }
 
diff --git a/crates/ra_hir_ty/src/utils.rs b/crates/ra_hir_ty/src/utils.rs
index e4ba890ef..0b1806a84 100644
--- a/crates/ra_hir_ty/src/utils.rs
+++ b/crates/ra_hir_ty/src/utils.rs
@@ -5,14 +5,14 @@ use std::sync::Arc;
 use hir_def::{
     adt::VariantData,
     db::DefDatabase,
+    generics::{GenericParams, TypeParamData},
+    path::Path,
     resolver::{HasResolver, TypeNs},
     type_ref::TypeRef,
-    TraitId, TypeAliasId, VariantId,
+    AssocContainerId, GenericDefId, Lookup, TraitId, TypeAliasId, TypeParamId, VariantId,
 };
-use hir_expand::name::{self, Name};
+use hir_expand::name::{name, Name};
 
-// FIXME: this is wrong, b/c it can't express `trait T: PartialEq<()>`.
-// We should return a `TraitREf` here.
 fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
     let resolver = trait_.resolver(db);
     // returning the iterator directly doesn't easily work because of
@@ -23,10 +23,10 @@ fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
         .where_predicates
         .iter()
         .filter_map(|pred| match &pred.type_ref {
-            TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(),
+            TypeRef::Path(p) if p == &Path::from(name![Self]) => pred.bound.as_path(),
             _ => None,
         })
-        .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) {
+        .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path.mod_path()) {
             Some(TypeNs::TraitId(t)) => Some(t),
             _ => None,
         })
@@ -82,3 +82,81 @@ pub(crate) fn make_mut_slice<T: Clone>(a: &mut Arc<[T]>) -> &mut [T] {
     }
     Arc::get_mut(a).unwrap()
 }
+
+pub(crate) fn generics(db: &impl DefDatabase, def: GenericDefId) -> Generics {
+    let parent_generics = parent_generic_def(db, def).map(|def| Box::new(generics(db, def)));
+    Generics { def, params: db.generic_params(def), parent_generics }
+}
+
+pub(crate) struct Generics {
+    def: GenericDefId,
+    pub(crate) params: Arc<GenericParams>,
+    parent_generics: Option<Box<Generics>>,
+}
+
+impl Generics {
+    pub(crate) fn iter<'a>(&'a self) -> impl Iterator<Item = (u32, &'a TypeParamData)> + 'a {
+        self.parent_generics
+            .as_ref()
+            .into_iter()
+            .flat_map(|it| it.params.types.iter())
+            .chain(self.params.types.iter())
+            .enumerate()
+            .map(|(i, (_local_id, p))| (i as u32, p))
+    }
+
+    pub(crate) fn iter_parent<'a>(&'a self) -> impl Iterator<Item = (u32, &'a TypeParamData)> + 'a {
+        self.parent_generics
+            .as_ref()
+            .into_iter()
+            .flat_map(|it| it.params.types.iter())
+            .enumerate()
+            .map(|(i, (_local_id, p))| (i as u32, p))
+    }
+
+    pub(crate) fn len(&self) -> usize {
+        self.len_split().0
+    }
+    /// (total, parents, child)
+    pub(crate) fn len_split(&self) -> (usize, usize, usize) {
+        let parent = self.parent_generics.as_ref().map_or(0, |p| p.len());
+        let child = self.params.types.len();
+        (parent + child, parent, child)
+    }
+    pub(crate) fn param_idx(&self, param: TypeParamId) -> u32 {
+        self.find_param(param).0
+    }
+    pub(crate) fn param_name(&self, param: TypeParamId) -> Name {
+        self.find_param(param).1.name.clone()
+    }
+    fn find_param(&self, param: TypeParamId) -> (u32, &TypeParamData) {
+        if param.parent == self.def {
+            let (idx, (_local_id, data)) = self
+                .params
+                .types
+                .iter()
+                .enumerate()
+                .find(|(_, (idx, _))| *idx == param.local_id)
+                .unwrap();
+            let (_total, parent_len, _child) = self.len_split();
+            return ((parent_len + idx) as u32, data);
+        }
+        self.parent_generics.as_ref().unwrap().find_param(param)
+    }
+}
+
+fn parent_generic_def(db: &impl DefDatabase, def: GenericDefId) -> Option<GenericDefId> {
+    let container = match def {
+        GenericDefId::FunctionId(it) => it.lookup(db).container,
+        GenericDefId::TypeAliasId(it) => it.lookup(db).container,
+        GenericDefId::ConstId(it) => it.lookup(db).container,
+        GenericDefId::EnumVariantId(it) => return Some(it.parent.into()),
+        GenericDefId::AdtId(_) | GenericDefId::TraitId(_) | GenericDefId::ImplId(_) => return None,
+    };
+
+    match container {
+        AssocContainerId::ImplId(it) => Some(it.into()),
+        AssocContainerId::TraitId(it) => Some(it.into()),
+        AssocContainerId::ContainerId(_) => None,
+    }
+}
diff --git a/crates/ra_ide/Cargo.toml b/crates/ra_ide/Cargo.toml
index e6383dd35..e3439ae31 100644
--- a/crates/ra_ide/Cargo.toml
+++ b/crates/ra_ide/Cargo.toml
@@ -11,6 +11,7 @@ doctest = false
 wasm = []
 
 [dependencies]
+either = "1.5"
 format-buf = "1.0.0"
 itertools = "0.8.0"
 join_to_string = "0.1.3"
diff --git a/crates/ra_ide/src/call_info.rs b/crates/ra_ide/src/call_info.rs
index d559dc4d0..2c2b6fa48 100644
--- a/crates/ra_ide/src/call_info.rs
+++ b/crates/ra_ide/src/call_info.rs
@@ -1,24 +1,26 @@
 //! FIXME: write short doc here
 
-use ra_db::SourceDatabase;
+use hir::db::AstDatabase;
 use ra_syntax::{
-    algo::ancestors_at_offset,
     ast::{self, ArgListOwner},
-    match_ast, AstNode, SyntaxNode, TextUnit,
+    match_ast, AstNode, SyntaxNode,
 };
 use test_utils::tested_by;
 
-use crate::{db::RootDatabase, CallInfo, FilePosition, FunctionSignature};
+use crate::{
+    db::RootDatabase, expand::descend_into_macros, CallInfo, FilePosition, FunctionSignature,
+};
 
 /// Computes parameter information for the given call expression.
 pub(crate) fn call_info(db: &RootDatabase, position: FilePosition) -> Option<CallInfo> {
-    let parse = db.parse(position.file_id);
-    let syntax = parse.tree().syntax().clone();
+    let file = db.parse_or_expand(position.file_id.into())?;
+    let token = file.token_at_offset(position.offset).next()?;
+    let token = descend_into_macros(db, position.file_id, token);
 
     // Find the calling expression and it's NameRef
-    let calling_node = FnCallNode::with_node(&syntax, position.offset)?;
+    let calling_node = FnCallNode::with_node(&token.value.parent())?;
     let name_ref = calling_node.name_ref()?;
-    let name_ref = hir::Source::new(position.file_id.into(), name_ref.syntax());
+    let name_ref = token.with_value(name_ref.syntax());
 
     let analyzer = hir::SourceAnalyzer::new(db, name_ref, None);
     let (mut call_info, has_self) = match &calling_node {
@@ -93,8 +95,8 @@ enum FnCallNode {
 }
 
 impl FnCallNode {
-    fn with_node(syntax: &SyntaxNode, offset: TextUnit) -> Option<FnCallNode> {
-        ancestors_at_offset(syntax, offset).find_map(|node| {
+    fn with_node(syntax: &SyntaxNode) -> Option<FnCallNode> {
+        syntax.ancestors().find_map(|node| {
             match_ast! {
                 match node {
                     ast::CallExpr(it) => { Some(FnCallNode::CallExpr(it)) },
@@ -589,4 +591,25 @@ fn f() {
         assert_eq!(info.label(), "foo!()");
         assert_eq!(info.doc().map(|it| it.into()), Some("empty macro".to_string()));
     }
+
+    #[test]
+    fn fn_signature_for_call_in_macro() {
+        let info = call_info(
+            r#"
+            macro_rules! id {
+                ($($tt:tt)*) => { $($tt)* }
+            }
+            fn foo() {
+
+            }
+            id! {
+                fn bar() {
+                    foo(<|>);
+                }
+            }
+            "#,
+        );
+
+        assert_eq!(info.label(), "fn foo()");
+    }
 }
diff --git a/crates/ra_ide/src/change.rs b/crates/ra_ide/src/change.rs
index 4a76d1dd8..387a9cafb 100644
--- a/crates/ra_ide/src/change.rs
+++ b/crates/ra_ide/src/change.rs
@@ -270,7 +270,6 @@ impl RootDatabase {
 
         self.query(hir::db::AstIdMapQuery).sweep(sweep);
 
-        self.query(hir::db::RawItemsWithSourceMapQuery).sweep(sweep);
         self.query(hir::db::BodyWithSourceMapQuery).sweep(sweep);
 
         self.query(hir::db::ExprScopesQuery).sweep(sweep);
@@ -309,7 +308,6 @@ impl RootDatabase {
             hir::db::StructDataQuery
             hir::db::EnumDataQuery
             hir::db::TraitDataQuery
-            hir::db::RawItemsWithSourceMapQuery
             hir::db::RawItemsQuery
             hir::db::CrateDefMapQuery
             hir::db::GenericParamsQuery
diff --git a/crates/ra_ide/src/completion/complete_dot.rs b/crates/ra_ide/src/completion/complete_dot.rs
index b6fe48627..294964887 100644
--- a/crates/ra_ide/src/completion/complete_dot.rs
+++ b/crates/ra_ide/src/completion/complete_dot.rs
@@ -27,7 +27,7 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     complete_methods(acc, ctx, &receiver_ty);
 
     // Suggest .await syntax for types that implement Future trait
-    if ctx.analyzer.impls_future(ctx.db, receiver_ty.into_ty()) {
+    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
         CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
             .detail("expr.await")
             .insert_text("await")
@@ -217,6 +217,39 @@ mod tests {
     }
 
     #[test]
+    fn test_method_completion_only_fitting_impls() {
+        assert_debug_snapshot!(
+            do_ref_completion(
+                r"
+            struct A<T> {}
+            impl A<u32> {
+                fn the_method(&self) {}
+            }
+            impl A<i32> {
+                fn the_other_method(&self) {}
+            }
+            fn foo(a: A<u32>) {
+               a.<|>
+            }
+            ",
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "the_method()",
+                source_range: [243; 243),
+                delete: [243; 243),
+                insert: "the_method()$0",
+                kind: Method,
+                lookup: "the_method",
+                detail: "fn the_method(&self)",
+            },
+        ]
+        "###
+        );
+    }
+
+    #[test]
     fn test_trait_method_completion() {
         assert_debug_snapshot!(
             do_ref_completion(
diff --git a/crates/ra_ide/src/completion/complete_path.rs b/crates/ra_ide/src/completion/complete_path.rs
index 89e0009a1..cc1f7c830 100644
--- a/crates/ra_ide/src/completion/complete_path.rs
+++ b/crates/ra_ide/src/completion/complete_path.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::{Adt, Either, HasSource, PathResolution};
+use hir::{Adt, PathResolution, ScopeDef};
 use ra_syntax::AstNode;
 use test_utils::tested_by;
 
@@ -18,17 +18,15 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
     match def {
         hir::ModuleDef::Module(module) => {
             let module_scope = module.scope(ctx.db);
-            for (name, def, import) in module_scope {
-                if let hir::ScopeDef::ModuleDef(hir::ModuleDef::BuiltinType(..)) = def {
-                    if ctx.use_item_syntax.is_some() {
+            for (name, def) in module_scope {
+                if ctx.use_item_syntax.is_some() {
+                    if let hir::ScopeDef::ModuleDef(hir::ModuleDef::BuiltinType(..)) = def {
                         tested_by!(dont_complete_primitive_in_use);
                         continue;
                     }
-                }
-                if Some(module) == ctx.module {
-                    if let Some(import) = import {
-                        if let Either::A(use_tree) = import.source(ctx.db).value {
-                            if use_tree.syntax().text_range().contains_inclusive(ctx.offset) {
+                    if let ScopeDef::Unknown = def {
+                        if let Some(name_ref) = ctx.name_ref_syntax.as_ref() {
+                            if &name_ref.syntax().text() == name.to_string().as_str() {
                                 // for `use self::foo<|>`, don't suggest `foo` as a completion
                                 tested_by!(dont_complete_current_use);
                                 continue;
@@ -36,6 +34,7 @@ pub(super) fn complete_path(acc: &mut Completions, ctx: &CompletionContext) {
                         }
                     }
                 }
+
                 acc.add_resolution(ctx, name.to_string(), &def);
             }
         }
diff --git a/crates/ra_ide/src/completion/complete_postfix.rs b/crates/ra_ide/src/completion/complete_postfix.rs
index 646a30c76..5470dc291 100644
--- a/crates/ra_ide/src/completion/complete_postfix.rs
+++ b/crates/ra_ide/src/completion/complete_postfix.rs
@@ -12,7 +12,7 @@ use crate::{
 };
 
 pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
-    if ctx.db.feature_flags.get("completion.enable-postfix") == false {
+    if !ctx.db.feature_flags.get("completion.enable-postfix") {
         return;
     }
 
diff --git a/crates/ra_ide/src/completion/complete_scope.rs b/crates/ra_ide/src/completion/complete_scope.rs
index d5739b58a..458d7525e 100644
--- a/crates/ra_ide/src/completion/complete_scope.rs
+++ b/crates/ra_ide/src/completion/complete_scope.rs
@@ -873,4 +873,41 @@ mod tests {
         "###
         );
     }
+
+    #[test]
+    fn completes_local_item() {
+        assert_debug_snapshot!(
+            do_reference_completion(
+                "
+                //- /main.rs
+                fn main() {
+                    return f<|>;
+                    fn frobnicate() {}
+                }
+                "
+            ),
+            @r###"
+        [
+            CompletionItem {
+                label: "frobnicate()",
+                source_range: [23; 24),
+                delete: [23; 24),
+                insert: "frobnicate()$0",
+                kind: Function,
+                lookup: "frobnicate",
+                detail: "fn frobnicate()",
+            },
+            CompletionItem {
+                label: "main()",
+                source_range: [23; 24),
+                delete: [23; 24),
+                insert: "main()$0",
+                kind: Function,
+                lookup: "main",
+                detail: "fn main()",
+            },
+        ]
+        "###
+        )
+    }
 }
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index b8345c91d..48d69f7e5 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -19,6 +19,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) offset: TextUnit,
     pub(super) token: SyntaxToken,
     pub(super) module: Option<hir::Module>,
+    pub(super) name_ref_syntax: Option<ast::NameRef>,
     pub(super) function_syntax: Option<ast::FnDef>,
     pub(super) use_item_syntax: Option<ast::UseItem>,
     pub(super) record_lit_syntax: Option<ast::RecordLit>,
@@ -54,13 +55,13 @@ impl<'a> CompletionContext<'a> {
         let src = hir::ModuleSource::from_position(db, position);
         let module = hir::Module::from_definition(
             db,
-            hir::Source { file_id: position.file_id.into(), value: src },
+            hir::InFile { file_id: position.file_id.into(), value: src },
         );
         let token =
             original_parse.tree().syntax().token_at_offset(position.offset).left_biased()?;
         let analyzer = hir::SourceAnalyzer::new(
             db,
-            hir::Source::new(position.file_id.into(), &token.parent()),
+            hir::InFile::new(position.file_id.into(), &token.parent()),
             Some(position.offset),
         );
         let mut ctx = CompletionContext {
@@ -69,6 +70,7 @@ impl<'a> CompletionContext<'a> {
             token,
             offset: position.offset,
             module,
+            name_ref_syntax: None,
             function_syntax: None,
             use_item_syntax: None,
             record_lit_syntax: None,
@@ -142,6 +144,8 @@ impl<'a> CompletionContext<'a> {
     }
 
     fn classify_name_ref(&mut self, original_file: SourceFile, name_ref: ast::NameRef) {
+        self.name_ref_syntax =
+            find_node_at_offset(original_file.syntax(), name_ref.syntax().text_range().start());
         let name_range = name_ref.syntax().text_range();
         if name_ref.syntax().parent().and_then(ast::RecordField::cast).is_some() {
             self.record_lit_syntax = find_node_at_offset(original_file.syntax(), self.offset);
@@ -188,10 +192,9 @@ impl<'a> CompletionContext<'a> {
             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();
-                    self.path_prefix = Some(path);
+            if let Some(path) = hir::Path::from_ast(path.clone()) {
+                if let Some(path_prefix) = path.qualifier() {
+                    self.path_prefix = Some(path_prefix);
                     return;
                 }
             }
@@ -240,16 +243,15 @@ 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,
+            self.dot_receiver_is_ambiguous_float_literal =
+                if let Some(ast::Expr::Literal(l)) = &self.dot_receiver {
+                    match l.kind() {
+                        ast::LiteralKind::FloatNumber { .. } => l.token().text().ends_with('.'),
+                        _ => false,
+                    }
+                } else {
+                    false
                 }
-            } else {
-                false
-            }
         }
         if let Some(method_call_expr) = ast::MethodCallExpr::cast(parent) {
             // As above
diff --git a/crates/ra_ide/src/db.rs b/crates/ra_ide/src/db.rs
index f739ebecd..47d0aed6f 100644
--- a/crates/ra_ide/src/db.rs
+++ b/crates/ra_ide/src/db.rs
@@ -5,7 +5,7 @@ use std::sync::Arc;
 use ra_db::{
     salsa::{self, Database, Durability},
     Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath,
-    SourceDatabase, SourceDatabaseExt, SourceRootId,
+    SourceDatabase, SourceRootId,
 };
 use rustc_hash::FxHashMap;
 
@@ -49,18 +49,6 @@ impl FileLoader for RootDatabase {
     }
 }
 
-impl hir::debug::HirDebugHelper for RootDatabase {
-    fn crate_name(&self, krate: CrateId) -> Option<String> {
-        self.debug_data.crate_names.get(&krate).cloned()
-    }
-    fn file_path(&self, file_id: FileId) -> Option<String> {
-        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))
-    }
-}
-
 impl salsa::Database for RootDatabase {
     fn salsa_runtime(&self) -> &salsa::Runtime<RootDatabase> {
         &self.runtime
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index cc1ccab4b..c50a70d99 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -96,7 +96,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     });
     let source_file = db.parse(file_id).tree();
     let src =
-        hir::Source { file_id: file_id.into(), value: hir::ModuleSource::SourceFile(source_file) };
+        hir::InFile { file_id: file_id.into(), value: hir::ModuleSource::SourceFile(source_file) };
     if let Some(m) = hir::Module::from_definition(db, src) {
         m.diagnostics(db, &mut sink);
     };
diff --git a/crates/ra_ide/src/display.rs b/crates/ra_ide/src/display.rs
index 30617412a..fbe89841b 100644
--- a/crates/ra_ide/src/display.rs
+++ b/crates/ra_ide/src/display.rs
@@ -15,7 +15,7 @@ pub use function_signature::FunctionSignature;
 pub use navigation_target::NavigationTarget;
 pub use structure::{file_structure, StructureNode};
 
-pub(crate) use navigation_target::{description_from_symbol, docs_from_symbol, ToNav};
+pub(crate) use navigation_target::ToNav;
 pub(crate) use short_label::ShortLabel;
 
 pub(crate) fn function_label(node: &ast::FnDef) -> String {
diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index 6ac60722b..b9ae67828 100644
--- a/crates/ra_ide/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -1,11 +1,12 @@
 //! FIXME: write short doc here
 
-use hir::{AssocItem, Either, FieldSource, HasSource, ModuleSource, Source};
+use either::Either;
+use hir::{AssocItem, FieldSource, HasSource, InFile, ModuleSource};
 use ra_db::{FileId, SourceDatabase};
 use ra_syntax::{
     ast::{self, DocCommentsOwner, NameOwner},
     match_ast, AstNode, SmolStr,
-    SyntaxKind::{self, BIND_PAT},
+    SyntaxKind::{self, BIND_PAT, TYPE_PARAM},
     TextRange,
 };
 
@@ -141,7 +142,7 @@ impl NavigationTarget {
     /// Allows `NavigationTarget` to be created from a `NameOwner`
     pub(crate) fn from_named(
         db: &RootDatabase,
-        node: Source<&dyn ast::NameOwner>,
+        node: InFile<&dyn ast::NameOwner>,
         docs: Option<String>,
         description: Option<String>,
     ) -> NavigationTarget {
@@ -230,34 +231,20 @@ impl ToNav for hir::Module {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.definition_source(db);
         let name = self.name(db).map(|it| it.to_string().into()).unwrap_or_default();
-        match &src.value {
-            ModuleSource::SourceFile(node) => {
-                let frange = original_range(db, src.with_value(node.syntax()));
-
-                NavigationTarget::from_syntax(
-                    frange.file_id,
-                    name,
-                    None,
-                    frange.range,
-                    node.syntax().kind(),
-                    None,
-                    None,
-                )
-            }
-            ModuleSource::Module(node) => {
-                let frange = original_range(db, src.with_value(node.syntax()));
-
-                NavigationTarget::from_syntax(
-                    frange.file_id,
-                    name,
-                    None,
-                    frange.range,
-                    node.syntax().kind(),
-                    node.doc_comment_text(),
-                    node.short_label(),
-                )
-            }
-        }
+        let syntax = match &src.value {
+            ModuleSource::SourceFile(node) => node.syntax(),
+            ModuleSource::Module(node) => node.syntax(),
+        };
+        let frange = original_range(db, src.with_value(syntax));
+        NavigationTarget::from_syntax(
+            frange.file_id,
+            name,
+            None,
+            frange.range,
+            syntax.kind(),
+            None,
+            None,
+        )
     }
 }
 
@@ -341,22 +328,43 @@ impl ToNav for hir::AssocItem {
 impl ToNav for hir::Local {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        let (full_range, focus_range) = match src.value {
-            Either::A(it) => {
-                (it.syntax().text_range(), it.name().map(|it| it.syntax().text_range()))
+        let node = match &src.value {
+            Either::Left(bind_pat) => {
+                bind_pat.name().map_or_else(|| bind_pat.syntax().clone(), |it| it.syntax().clone())
             }
-            Either::B(it) => (it.syntax().text_range(), Some(it.self_kw_token().text_range())),
+            Either::Right(it) => it.syntax().clone(),
         };
+        let full_range = original_range(db, src.with_value(&node));
         let name = match self.name(db) {
             Some(it) => it.to_string().into(),
             None => "".into(),
         };
         NavigationTarget {
-            file_id: src.file_id.original_file(db),
+            file_id: full_range.file_id,
             name,
             kind: BIND_PAT,
-            full_range,
-            focus_range,
+            full_range: full_range.range,
+            focus_range: None,
+            container_name: None,
+            description: None,
+            docs: None,
+        }
+    }
+}
+
+impl ToNav for hir::TypeParam {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        let src = self.source(db);
+        let range = match src.value {
+            Either::Left(it) => it.syntax().text_range(),
+            Either::Right(it) => it.syntax().text_range(),
+        };
+        NavigationTarget {
+            file_id: src.file_id.original_file(db),
+            name: self.name(db).to_string().into(),
+            kind: TYPE_PARAM,
+            full_range: range,
+            focus_range: None,
             container_name: None,
             description: None,
             docs: None,
diff --git a/crates/ra_ide/src/expand.rs b/crates/ra_ide/src/expand.rs
index 2f1abf509..7a22bb0a4 100644
--- a/crates/ra_ide/src/expand.rs
+++ b/crates/ra_ide/src/expand.rs
@@ -1,42 +1,71 @@
 //! Utilities to work with files, produced by macros.
 use std::iter::successors;
 
-use hir::Source;
+use hir::{InFile, Origin};
 use ra_db::FileId;
-use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxToken};
+use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxToken, TextRange};
 
 use crate::{db::RootDatabase, FileRange};
 
-pub(crate) fn original_range(db: &RootDatabase, node: Source<&SyntaxNode>) -> FileRange {
-    let expansion = match node.file_id.expansion_info(db) {
-        None => {
+pub(crate) fn original_range(db: &RootDatabase, node: InFile<&SyntaxNode>) -> FileRange {
+    if let Some((range, Origin::Call)) = original_range_and_origin(db, node) {
+        return range;
+    }
+
+    if let Some(expansion) = node.file_id.expansion_info(db) {
+        if let Some(call_node) = expansion.call_node() {
             return FileRange {
-                file_id: node.file_id.original_file(db),
-                range: node.value.text_range(),
-            }
+                file_id: call_node.file_id.original_file(db),
+                range: call_node.value.text_range(),
+            };
         }
-        Some(it) => it,
-    };
-    // FIXME: the following completely wrong.
-    //
-    // *First*, we should try to map first and last tokens of node, and, if that
-    // fails, return the range of the overall macro expansions.
-    //
-    // *Second*, we should handle recurside macro expansions
-
-    let token = node
-        .value
-        .descendants_with_tokens()
-        .filter_map(|it| it.into_token())
-        .find_map(|it| expansion.map_token_up(node.with_value(&it)));
-
-    match token {
-        Some(it) => {
-            FileRange { file_id: it.file_id.original_file(db), range: it.value.text_range() }
+    }
+
+    FileRange { file_id: node.file_id.original_file(db), range: node.value.text_range() }
+}
+
+fn original_range_and_origin(
+    db: &RootDatabase,
+    node: InFile<&SyntaxNode>,
+) -> Option<(FileRange, Origin)> {
+    let expansion = node.file_id.expansion_info(db)?;
+
+    // the input node has only one token ?
+    let single = node.value.first_token()? == node.value.last_token()?;
+
+    // FIXME: We should handle recurside macro expansions
+    let (range, origin) = node.value.descendants().find_map(|it| {
+        let first = it.first_token()?;
+        let last = it.last_token()?;
+
+        if !single && first == last {
+            return None;
         }
-        None => {
-            FileRange { file_id: node.file_id.original_file(db), range: node.value.text_range() }
+
+        // Try to map first and last tokens of node, and, if success, return the union range of mapped tokens
+        let (first, first_origin) = expansion.map_token_up(node.with_value(&first))?;
+        let (last, last_origin) = expansion.map_token_up(node.with_value(&last))?;
+
+        if first.file_id != last.file_id || first_origin != last_origin {
+            return None;
         }
+
+        // FIXME: Add union method in TextRange
+        Some((
+            first.with_value(union_range(first.value.text_range(), last.value.text_range())),
+            first_origin,
+        ))
+    })?;
+
+    return Some((
+        FileRange { file_id: range.file_id.original_file(db), range: range.value },
+        origin,
+    ));
+
+    fn union_range(a: TextRange, b: TextRange) -> TextRange {
+        let start = a.start().min(b.start());
+        let end = a.end().max(b.end());
+        TextRange::from_to(start, end)
     }
 }
 
@@ -44,8 +73,8 @@ pub(crate) fn descend_into_macros(
     db: &RootDatabase,
     file_id: FileId,
     token: SyntaxToken,
-) -> Source<SyntaxToken> {
-    let src = Source::new(file_id.into(), token);
+) -> InFile<SyntaxToken> {
+    let src = InFile::new(file_id.into(), token);
 
     successors(Some(src), |token| {
         let macro_call = token.value.ancestors().find_map(ast::MacroCall::cast)?;
diff --git a/crates/ra_ide/src/expand_macro.rs b/crates/ra_ide/src/expand_macro.rs
index abc602244..bdbc31704 100644
--- a/crates/ra_ide/src/expand_macro.rs
+++ b/crates/ra_ide/src/expand_macro.rs
@@ -22,7 +22,7 @@ pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<
     let name_ref = find_node_at_offset::<ast::NameRef>(file.syntax(), position.offset)?;
     let mac = name_ref.syntax().ancestors().find_map(ast::MacroCall::cast)?;
 
-    let source = hir::Source::new(position.file_id.into(), mac.syntax());
+    let source = hir::InFile::new(position.file_id.into(), mac.syntax());
     let expanded = expand_macro_recur(db, source, source.with_value(&mac))?;
 
     // FIXME:
@@ -34,8 +34,8 @@ pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<
 
 fn expand_macro_recur(
     db: &RootDatabase,
-    source: hir::Source<&SyntaxNode>,
-    macro_call: hir::Source<&ast::MacroCall>,
+    source: hir::InFile<&SyntaxNode>,
+    macro_call: hir::InFile<&ast::MacroCall>,
 ) -> Option<SyntaxNode> {
     let analyzer = hir::SourceAnalyzer::new(db, source, None);
     let expansion = analyzer.expand(db, macro_call)?;
@@ -46,7 +46,7 @@ fn expand_macro_recur(
     let mut replaces = FxHashMap::default();
 
     for child in children.into_iter() {
-        let node = hir::Source::new(macro_file_id, &child);
+        let node = hir::InFile::new(macro_file_id, &child);
         if let Some(new_node) = expand_macro_recur(db, source, node) {
             // Replace the whole node if it is root
             // `replace_descendants` will not replace the parent node
@@ -86,21 +86,18 @@ fn insert_whitespaces(syn: SyntaxNode) -> String {
         let mut is_next = |f: fn(SyntaxKind) -> bool, default| -> bool {
             token_iter.peek().map(|it| f(it.kind())).unwrap_or(default)
         };
-        let is_last = |f: fn(SyntaxKind) -> bool, default| -> bool {
-            last.map(|it| f(it)).unwrap_or(default)
-        };
+        let is_last =
+            |f: fn(SyntaxKind) -> bool, default| -> bool { last.map(f).unwrap_or(default) };
 
         res += &match token.kind() {
-            k @ _ if is_text(k) && is_next(|it| !it.is_punct(), true) => {
-                token.text().to_string() + " "
-            }
+            k if is_text(k) && is_next(|it| !it.is_punct(), true) => token.text().to_string() + " ",
             L_CURLY if is_next(|it| it != R_CURLY, true) => {
                 indent += 1;
-                let leading_space = if is_last(|it| is_text(it), false) { " " } else { "" };
+                let leading_space = if is_last(is_text, false) { " " } else { "" };
                 format!("{}{{\n{}", leading_space, "  ".repeat(indent))
             }
             R_CURLY if is_last(|it| it != L_CURLY, true) => {
-                indent = indent.checked_sub(1).unwrap_or(0);
+                indent = indent.saturating_sub(1);
                 format!("\n{}}}", "  ".repeat(indent))
             }
             R_CURLY => format!("}}\n{}", "  ".repeat(indent)),
diff --git a/crates/ra_ide/src/extend_selection.rs b/crates/ra_ide/src/extend_selection.rs
index 4b7bfc0b1..1ec41a117 100644
--- a/crates/ra_ide/src/extend_selection.rs
+++ b/crates/ra_ide/src/extend_selection.rs
@@ -34,6 +34,7 @@ fn try_extend_selection(root: &SyntaxNode, range: TextRange) -> Option<TextRange
         ARG_LIST,
         ARRAY_EXPR,
         TUPLE_EXPR,
+        TUPLE_TYPE,
         WHERE_CLAUSE,
     ];
 
@@ -137,7 +138,7 @@ fn extend_ws(root: &SyntaxNode, ws: SyntaxToken, offset: TextUnit) -> TextRange
     ws.text_range()
 }
 
-fn pick_best<'a>(l: SyntaxToken, r: SyntaxToken) -> SyntaxToken {
+fn pick_best(l: SyntaxToken, r: SyntaxToken) -> SyntaxToken {
     return if priority(&r) > priority(&l) { r } else { l };
     fn priority(n: &SyntaxToken) -> usize {
         match n.kind() {
@@ -174,12 +175,7 @@ fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
         TYPE_BOUND => T![+],
         _ => T![,],
     };
-    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Prev) {
-        return Some(TextRange::from_to(
-            delimiter_node.text_range().start(),
-            node.text_range().end(),
-        ));
-    }
+
     if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Next) {
         // Include any following whitespace when delimiter is after list item.
         let final_node = delimiter_node
@@ -190,6 +186,12 @@ fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
 
         return Some(TextRange::from_to(node.text_range().start(), final_node.text_range().end()));
     }
+    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Prev) {
+        return Some(TextRange::from_to(
+            delimiter_node.text_range().start(),
+            node.text_range().end(),
+        ));
+    }
 
     None
 }
@@ -250,14 +252,14 @@ mod tests {
     fn test_extend_selection_list() {
         do_check(r#"fn foo(<|>x: i32) {}"#, &["x", "x: i32"]);
         do_check(r#"fn foo(<|>x: i32, y: i32) {}"#, &["x", "x: i32", "x: i32, "]);
-        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,"]);
+        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,", "(x: i32,y: i32)"]);
         do_check(r#"fn foo(x: i32, <|>y: i32) {}"#, &["y", "y: i32", ", y: i32"]);
-        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", ", y: i32"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", "y: i32, "]);
         do_check(r#"fn foo(x: i32,<|>y: i32) {}"#, &["y", "y: i32", ",y: i32"]);
 
         do_check(r#"const FOO: [usize; 2] = [ 22<|> , 33];"#, &["22", "22 , "]);
         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#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", "33 ,", "[ 22 , 33 ,]"]);
 
         do_check(r#"fn main() { (1, 2<|>) }"#, &["2", ", 2", "(1, 2)"]);
 
@@ -276,7 +278,7 @@ const FOO: [usize; 2] = [
     22
     , 33<|>,
 ]"#,
-            &["33", ", 33"],
+            &["33", "33,"],
         );
     }
 
@@ -424,7 +426,7 @@ fn foo<R>()
         do_check(r#"fn foo<T>() where T: <|>Copy +Display"#, &["Copy", "Copy +"]);
         do_check(r#"fn foo<T>() where T: <|>Copy+Display"#, &["Copy", "Copy+"]);
         do_check(r#"fn foo<T>() where T: Copy + <|>Display"#, &["Display", "+ Display"]);
-        do_check(r#"fn foo<T>() where T: Copy + <|>Display + Sync"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T>() where T: Copy + <|>Display + Sync"#, &["Display", "Display + "]);
         do_check(r#"fn foo<T>() where T: Copy +<|>Display"#, &["Display", "+Display"]);
     }
 
@@ -435,7 +437,7 @@ fn foo<R>()
         do_check(r#"fn foo<T: <|>Copy +Display>() {}"#, &["Copy", "Copy +"]);
         do_check(r#"fn foo<T: <|>Copy+Display>() {}"#, &["Copy", "Copy+"]);
         do_check(r#"fn foo<T: Copy + <|>Display>() {}"#, &["Display", "+ Display"]);
-        do_check(r#"fn foo<T: Copy + <|>Display + Sync>() {}"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T: Copy + <|>Display + Sync>() {}"#, &["Display", "Display + "]);
         do_check(r#"fn foo<T: Copy +<|>Display>() {}"#, &["Display", "+Display"]);
         do_check(
             r#"fn foo<T: Copy<|> + Display, U: Copy>() {}"#,
@@ -449,4 +451,56 @@ fn foo<R>()
             ],
         );
     }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_type() {
+        do_check(
+            r#"fn main() { let _: (krate, <|>_crate_def_map, module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let _: (krate,<|>_crate_def_map,module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let _: (
+    krate,
+    _crate<|>_def_map,
+    module_id
+) = (); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_rvalue() {
+        do_check(
+            r#"fn main() { let var = (krate, _crate_def_map<|>, module_id); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let var = (krate,_crate<|>_def_map,module_id); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let var = (
+    krate,
+    _crate_def_map<|>,
+    module_id
+); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
 }
diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index c10a6c844..79d332e8c 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -1,9 +1,11 @@
 //! FIXME: write short doc here
 
-use hir::{db::AstDatabase, Source};
+use hir::{db::AstDatabase, InFile};
 use ra_syntax::{
     ast::{self, DocCommentsOwner},
-    match_ast, AstNode, SyntaxNode,
+    match_ast, AstNode,
+    SyntaxKind::*,
+    SyntaxNode, SyntaxToken, TokenAtOffset,
 };
 
 use crate::{
@@ -19,25 +21,33 @@ pub(crate) fn goto_definition(
     position: FilePosition,
 ) -> Option<RangeInfo<Vec<NavigationTarget>>> {
     let file = db.parse_or_expand(position.file_id.into())?;
-    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
-    let token = descend_into_macros(db, position.file_id, token);
+    let original_token = pick_best(file.token_at_offset(position.offset))?;
+    let token = descend_into_macros(db, position.file_id, original_token.clone());
 
-    let res = match_ast! {
+    let nav_targets = match_ast! {
         match (token.value.parent()) {
             ast::NameRef(name_ref) => {
-                let navs = reference_definition(db, token.with_value(&name_ref)).to_vec();
-                RangeInfo::new(name_ref.syntax().text_range(), navs.to_vec())
+                reference_definition(db, token.with_value(&name_ref)).to_vec()
             },
             ast::Name(name) => {
-                let navs = name_definition(db, token.with_value(&name))?;
-                RangeInfo::new(name.syntax().text_range(), navs)
-
+                name_definition(db, token.with_value(&name))?
             },
             _ => return None,
         }
     };
 
-    Some(res)
+    Some(RangeInfo::new(original_token.text_range(), nav_targets))
+}
+
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
 }
 
 #[derive(Debug)]
@@ -58,15 +68,17 @@ impl ReferenceResult {
 
 pub(crate) fn reference_definition(
     db: &RootDatabase,
-    name_ref: Source<&ast::NameRef>,
+    name_ref: InFile<&ast::NameRef>,
 ) -> ReferenceResult {
     use self::ReferenceResult::*;
 
     let name_kind = classify_name_ref(db, name_ref).map(|d| d.kind);
     match name_kind {
-        Some(Macro(mac)) => return Exact(mac.to_nav(db)),
-        Some(Field(field)) => return Exact(field.to_nav(db)),
-        Some(AssocItem(assoc)) => return Exact(assoc.to_nav(db)),
+        Some(Macro(it)) => return Exact(it.to_nav(db)),
+        Some(Field(it)) => return Exact(it.to_nav(db)),
+        Some(TypeParam(it)) => return Exact(it.to_nav(db)),
+        Some(AssocItem(it)) => return Exact(it.to_nav(db)),
+        Some(Local(it)) => return Exact(it.to_nav(db)),
         Some(Def(def)) => match NavigationTarget::from_def(db, def) {
             Some(nav) => return Exact(nav),
             None => return Approximate(vec![]),
@@ -77,10 +89,6 @@ pub(crate) fn reference_definition(
             // us to the actual type
             return Exact(imp.to_nav(db));
         }
-        Some(Local(local)) => return Exact(local.to_nav(db)),
-        Some(GenericParam(_)) => {
-            // FIXME: go to the generic param def
-        }
         None => {}
     };
 
@@ -94,7 +102,7 @@ pub(crate) fn reference_definition(
 
 pub(crate) fn name_definition(
     db: &RootDatabase,
-    name: Source<&ast::Name>,
+    name: InFile<&ast::Name>,
 ) -> Option<Vec<NavigationTarget>> {
     let parent = name.value.syntax().parent()?;
 
@@ -115,7 +123,7 @@ pub(crate) fn name_definition(
     None
 }
 
-fn named_target(db: &RootDatabase, node: Source<&SyntaxNode>) -> Option<NavigationTarget> {
+fn named_target(db: &RootDatabase, node: InFile<&SyntaxNode>) -> Option<NavigationTarget> {
     match_ast! {
         match (node.value) {
             ast::StructDef(it) => {
@@ -213,21 +221,44 @@ fn named_target(db: &RootDatabase, node: Source<&SyntaxNode>) -> Option<Navigati
 
 #[cfg(test)]
 mod tests {
-    use test_utils::covers;
+    use test_utils::{assert_eq_text, covers};
 
     use crate::mock_analysis::analysis_and_position;
 
-    fn check_goto(fixture: &str, expected: &str) {
+    fn check_goto(fixture: &str, expected: &str, expected_range: &str) {
         let (analysis, pos) = analysis_and_position(fixture);
 
         let mut navs = analysis.goto_definition(pos).unwrap().unwrap().info;
         assert_eq!(navs.len(), 1);
+
         let nav = navs.pop().unwrap();
+        let file_text = analysis.file_text(nav.file_id()).unwrap();
+
+        let mut actual = file_text[nav.full_range()].to_string();
+        if let Some(focus) = nav.focus_range() {
+            actual += "|";
+            actual += &file_text[focus];
+        }
+
+        if !expected_range.contains("...") {
+            test_utils::assert_eq_text!(&actual, expected_range);
+        } else {
+            let mut parts = expected_range.split("...");
+            let prefix = parts.next().unwrap();
+            let suffix = parts.next().unwrap();
+            assert!(
+                actual.starts_with(prefix) && actual.ends_with(suffix),
+                "\nExpected: {}\n Actual: {}\n",
+                expected_range,
+                actual
+            );
+        }
+
         nav.assert_match(expected);
     }
 
     #[test]
-    fn goto_definition_works_in_items() {
+    fn goto_def_in_items() {
         check_goto(
             "
             //- /lib.rs
@@ -235,6 +266,20 @@ mod tests {
             enum E { X(Foo<|>) }
             ",
             "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "struct Foo;|Foo",
+        );
+    }
+
+    #[test]
+    fn goto_def_at_start_of_item() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            enum E { X(<|>Foo) }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+            "struct Foo;|Foo",
         );
     }
 
@@ -247,61 +292,65 @@ mod tests {
             mod a;
             mod b;
             enum E { X(Foo<|>) }
+
             //- /a.rs
             struct Foo;
+
             //- /b.rs
             struct Foo;
             ",
             "Foo STRUCT_DEF FileId(2) [0; 11) [7; 10)",
+            "struct Foo;|Foo",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_module_declaration() {
+    fn goto_def_for_module_declaration() {
         check_goto(
             "
             //- /lib.rs
             mod <|>foo;
+
             //- /foo.rs
             // empty
             ",
             "foo SOURCE_FILE FileId(2) [0; 10)",
+            "// empty\n\n",
         );
 
         check_goto(
             "
             //- /lib.rs
             mod <|>foo;
+
             //- /foo/mod.rs
             // empty
             ",
             "foo SOURCE_FILE FileId(2) [0; 10)",
+            "// empty\n\n",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macros() {
-        covers!(goto_definition_works_for_macros);
+    fn goto_def_for_macros() {
+        covers!(goto_def_for_macros);
         check_goto(
             "
             //- /lib.rs
-            macro_rules! foo {
-                () => {
-                    {}
-                };
-            }
+            macro_rules! foo { () => { () } }
 
             fn bar() {
                 <|>foo!();
             }
             ",
-            "foo MACRO_CALL FileId(1) [0; 50) [13; 16)",
+            "foo MACRO_CALL FileId(1) [0; 33) [13; 16)",
+            "macro_rules! foo { () => { () } }|foo",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macros_from_other_crates() {
-        covers!(goto_definition_works_for_macros);
+    fn goto_def_for_macros_from_other_crates() {
+        covers!(goto_def_for_macros);
         check_goto(
             "
             //- /lib.rs
@@ -312,18 +361,15 @@ mod tests {
 
             //- /foo/lib.rs
             #[macro_export]
-            macro_rules! foo {
-                () => {
-                    {}
-                };
-            }
+            macro_rules! foo { () => { () } }
             ",
-            "foo MACRO_CALL FileId(2) [0; 66) [29; 32)",
+            "foo MACRO_CALL FileId(2) [0; 49) [29; 32)",
+            "#[macro_export]\nmacro_rules! foo { () => { () } }|foo",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macros_in_use_tree() {
+    fn goto_def_for_macros_in_use_tree() {
         check_goto(
             "
             //- /lib.rs
@@ -331,18 +377,15 @@ mod tests {
 
             //- /foo/lib.rs
             #[macro_export]
-            macro_rules! foo {
-                () => {
-                    {}
-                };
-            }
+            macro_rules! foo { () => { () } }
             ",
-            "foo MACRO_CALL FileId(2) [0; 66) [29; 32)",
+            "foo MACRO_CALL FileId(2) [0; 49) [29; 32)",
+            "#[macro_export]\nmacro_rules! foo { () => { () } }|foo",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macro_defined_fn_with_arg() {
+    fn goto_def_for_macro_defined_fn_with_arg() {
         check_goto(
             "
             //- /lib.rs
@@ -350,20 +393,19 @@ mod tests {
                 ($name:ident) => (fn $name() {})
             }
 
-            define_fn!(
-                foo
-            )
+            define_fn!(foo);
 
             fn bar() {
                <|>foo();
             }
             ",
-            "foo FN_DEF FileId(1) [80; 83) [80; 83)",
+            "foo FN_DEF FileId(1) [64; 80) [75; 78)",
+            "define_fn!(foo);|foo",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_macro_defined_fn_no_arg() {
+    fn goto_def_for_macro_defined_fn_no_arg() {
         check_goto(
             "
             //- /lib.rs
@@ -377,32 +419,70 @@ mod tests {
                <|>foo();
             }
             ",
-            "foo FN_DEF FileId(1) [39; 42) [39; 42)",
+            "foo FN_DEF FileId(1) [51; 64) [51; 64)",
+            "define_fn!();|define_fn!();",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_methods() {
-        covers!(goto_definition_works_for_methods);
+    fn goto_definition_works_for_macro_inside_pattern() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! foo {() => {0}}
+
+            fn bar() {
+                match (0,1) {
+                    (<|>foo!(), _) => {}
+                }
+            }
+            ",
+            "foo MACRO_CALL FileId(1) [0; 28) [13; 16)",
+            "macro_rules! foo {() => {0}}|foo",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macro_inside_match_arm_lhs() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! foo {() => {0}}
+
+            fn bar() {
+                match 0 {
+                    <|>foo!() => {}
+                }
+            }
+            ",
+            "foo MACRO_CALL FileId(1) [0; 28) [13; 16)",
+            "macro_rules! foo {() => {0}}|foo",
+        );
+    }
+
+    #[test]
+    fn goto_def_for_methods() {
+        covers!(goto_def_for_methods);
         check_goto(
             "
             //- /lib.rs
             struct Foo;
             impl Foo {
-                fn frobnicate(&self) {  }
+                fn frobnicate(&self) { }
             }
 
             fn bar(foo: &Foo) {
                 foo.frobnicate<|>();
             }
             ",
-            "frobnicate FN_DEF FileId(1) [27; 52) [30; 40)",
+            "frobnicate FN_DEF FileId(1) [27; 51) [30; 40)",
+            "fn frobnicate(&self) { }|frobnicate",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_fields() {
-        covers!(goto_definition_works_for_fields);
+    fn goto_def_for_fields() {
+        covers!(goto_def_for_fields);
         check_goto(
             "
             //- /lib.rs
@@ -415,12 +495,13 @@ mod tests {
             }
             ",
             "spam RECORD_FIELD_DEF FileId(1) [17; 26) [17; 21)",
+            "spam: u32|spam",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_record_fields() {
-        covers!(goto_definition_works_for_record_fields);
+    fn goto_def_for_record_fields() {
+        covers!(goto_def_for_record_fields);
         check_goto(
             "
             //- /lib.rs
@@ -435,29 +516,48 @@ mod tests {
             }
             ",
             "spam RECORD_FIELD_DEF FileId(1) [17; 26) [17; 21)",
+            "spam: u32|spam",
+        );
+    }
+
+    #[test]
+    fn goto_for_tuple_fields() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo(u32);
+
+            fn bar() {
+                let foo = Foo(0);
+                foo.<|>0;
+            }
+            ",
+            "TUPLE_FIELD_DEF FileId(1) [11; 14)",
+            "u32",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_ufcs_inherent_methods() {
+    fn goto_def_for_ufcs_inherent_methods() {
         check_goto(
             "
             //- /lib.rs
             struct Foo;
             impl Foo {
-                fn frobnicate() {  }
+                fn frobnicate() { }
             }
 
             fn bar(foo: &Foo) {
                 Foo::frobnicate<|>();
             }
             ",
-            "frobnicate FN_DEF FileId(1) [27; 47) [30; 40)",
+            "frobnicate FN_DEF FileId(1) [27; 46) [30; 40)",
+            "fn frobnicate() { }|frobnicate",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_ufcs_trait_methods_through_traits() {
+    fn goto_def_for_ufcs_trait_methods_through_traits() {
         check_goto(
             "
             //- /lib.rs
@@ -470,11 +570,12 @@ mod tests {
             }
             ",
             "frobnicate FN_DEF FileId(1) [16; 32) [19; 29)",
+            "fn frobnicate();|frobnicate",
         );
     }
 
     #[test]
-    fn goto_definition_works_for_ufcs_trait_methods_through_self() {
+    fn goto_def_for_ufcs_trait_methods_through_self() {
         check_goto(
             "
             //- /lib.rs
@@ -489,6 +590,7 @@ mod tests {
             }
             ",
             "frobnicate FN_DEF FileId(1) [30; 46) [33; 43)",
+            "fn frobnicate();|frobnicate",
         );
     }
 
@@ -505,6 +607,7 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [12; 73)",
+            "impl Foo {...}",
         );
 
         check_goto(
@@ -518,6 +621,7 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [12; 73)",
+            "impl Foo {...}",
         );
 
         check_goto(
@@ -531,6 +635,7 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [15; 75)",
+            "impl Foo {...}",
         );
 
         check_goto(
@@ -543,6 +648,7 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [15; 62)",
+            "impl Foo {...}",
         );
     }
 
@@ -562,6 +668,7 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [49; 115)",
+            "impl Make for Foo {...}",
         );
 
         check_goto(
@@ -578,17 +685,19 @@ mod tests {
             }
             ",
             "impl IMPL_BLOCK FileId(1) [49; 115)",
+            "impl Make for Foo {...}",
         );
     }
 
     #[test]
-    fn goto_definition_works_when_used_on_definition_name_itself() {
+    fn goto_def_when_used_on_definition_name_itself() {
         check_goto(
             "
             //- /lib.rs
             struct Foo<|> { value: u32 }
             ",
             "Foo STRUCT_DEF FileId(1) [0; 25) [7; 10)",
+            "struct Foo { value: u32 }|Foo",
         );
 
         check_goto(
@@ -599,15 +708,16 @@ mod tests {
             }
             "#,
             "field RECORD_FIELD_DEF FileId(1) [17; 30) [17; 22)",
+            "field: string|field",
         );
 
         check_goto(
             "
             //- /lib.rs
-            fn foo_test<|>() {
-            }
+            fn foo_test<|>() { }
             ",
             "foo_test FN_DEF FileId(1) [0; 17) [3; 11)",
+            "fn foo_test() { }|foo_test",
         );
 
         check_goto(
@@ -618,6 +728,7 @@ mod tests {
             }
             ",
             "Foo ENUM_DEF FileId(1) [0; 25) [5; 8)",
+            "enum Foo {...}|Foo",
         );
 
         check_goto(
@@ -630,22 +741,25 @@ mod tests {
             }
             ",
             "Variant2 ENUM_VARIANT FileId(1) [29; 37) [29; 37)",
+            "Variant2|Variant2",
         );
 
         check_goto(
             r#"
             //- /lib.rs
-            static inner<|>: &str = "";
+            static INNER<|>: &str = "";
             "#,
-            "inner STATIC_DEF FileId(1) [0; 24) [7; 12)",
+            "INNER STATIC_DEF FileId(1) [0; 24) [7; 12)",
+            "static INNER: &str = \"\";|INNER",
         );
 
         check_goto(
             r#"
             //- /lib.rs
-            const inner<|>: &str = "";
+            const INNER<|>: &str = "";
             "#,
-            "inner CONST_DEF FileId(1) [0; 23) [6; 11)",
+            "INNER CONST_DEF FileId(1) [0; 23) [6; 11)",
+            "const INNER: &str = \"\";|INNER",
         );
 
         check_goto(
@@ -654,24 +768,25 @@ mod tests {
             type Thing<|> = Option<()>;
             "#,
             "Thing TYPE_ALIAS_DEF FileId(1) [0; 24) [5; 10)",
+            "type Thing = Option<()>;|Thing",
         );
 
         check_goto(
             r#"
             //- /lib.rs
-            trait Foo<|> {
-            }
+            trait Foo<|> { }
             "#,
             "Foo TRAIT_DEF FileId(1) [0; 13) [6; 9)",
+            "trait Foo { }|Foo",
         );
 
         check_goto(
             r#"
             //- /lib.rs
-            mod bar<|> {
-            }
+            mod bar<|> { }
             "#,
             "bar MODULE FileId(1) [0; 11) [4; 7)",
+            "mod bar { }|bar",
         );
     }
 
@@ -689,8 +804,128 @@ mod tests {
                     fo<|>o();
                 }
             }
+            mod confuse_index { fn foo(); }
             ",
             "foo FN_DEF FileId(1) [52; 63) [55; 58)",
+            "fn foo() {}|foo",
         );
     }
+
+    #[test]
+    fn goto_through_format() {
+        check_goto(
+            "
+            //- /lib.rs
+            #[macro_export]
+            macro_rules! format {
+                ($($arg:tt)*) => ($crate::fmt::format($crate::__export::format_args!($($arg)*)))
+            }
+            #[rustc_builtin_macro]
+            #[macro_export]
+            macro_rules! format_args {
+                ($fmt:expr) => ({ /* compiler built-in */ });
+                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            pub mod __export {
+                pub use crate::format_args;
+                fn foo() {} // for index confusion
+            }
+            fn foo() -> i8 {}
+            fn test() {
+                format!(\"{}\", fo<|>o())
+            }
+            ",
+            "foo FN_DEF FileId(1) [398; 415) [401; 404)",
+            "fn foo() -> i8 {}|foo",
+        );
+    }
+
+    #[test]
+    fn goto_for_type_param() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<T> {
+                t: <|>T,
+            }
+            ",
+            "T TYPE_PARAM FileId(1) [11; 12)",
+            "T",
+        );
+    }
+
+    #[test]
+    fn goto_within_macro() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! id {
+                ($($tt:tt)*) => ($($tt)*)
+            }
+
+            fn foo() {
+                let x = 1;
+                id!({
+                    let y = <|>x;
+                    let z = y;
+                });
+            }
+            ",
+            "x BIND_PAT FileId(1) [69; 70)",
+            "x",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! id {
+                ($($tt:tt)*) => ($($tt)*)
+            }
+
+            fn foo() {
+                let x = 1;
+                id!({
+                    let y = x;
+                    let z = <|>y;
+                });
+            }
+            ",
+            "y BIND_PAT FileId(1) [98; 99)",
+            "y",
+        );
+    }
+
+    #[test]
+    fn goto_def_in_local_fn() {
+        check_goto(
+            "
+            //- /lib.rs
+            fn main() {
+                fn foo() {
+                    let x = 92;
+                    <|>x;
+                }
+            }
+            ",
+            "x BIND_PAT FileId(1) [39; 40)",
+            "x",
+        );
+    }
+
+    #[test]
+    fn goto_def_for_field_init_shorthand() {
+        covers!(goto_def_for_field_init_shorthand);
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo { x: i32 }
+            fn main() {
+                let x = 92;
+                Foo { x<|> };
+            }
+            ",
+            "x RECORD_FIELD_DEF FileId(1) [13; 19) [13; 14)",
+            "x: i32|x",
+        )
+    }
 }
diff --git a/crates/ra_ide/src/goto_type_definition.rs b/crates/ra_ide/src/goto_type_definition.rs
index 992a08809..ce8b6c72a 100644
--- a/crates/ra_ide/src/goto_type_definition.rs
+++ b/crates/ra_ide/src/goto_type_definition.rs
@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 
 use hir::db::AstDatabase;
-use ra_syntax::{ast, AstNode};
+use ra_syntax::{ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset};
 
 use crate::{
     db::RootDatabase, display::ToNav, expand::descend_into_macros, FilePosition, NavigationTarget,
@@ -13,7 +13,7 @@ pub(crate) fn goto_type_definition(
     position: FilePosition,
 ) -> Option<RangeInfo<Vec<NavigationTarget>>> {
     let file = db.parse_or_expand(position.file_id.into())?;
-    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
+    let token = pick_best(file.token_at_offset(position.offset))?;
     let token = descend_into_macros(db, position.file_id, token);
 
     let node = token.value.ancestors().find_map(|token| {
@@ -41,6 +41,17 @@ pub(crate) fn goto_type_definition(
     Some(RangeInfo::new(node.text_range(), vec![nav]))
 }
 
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::mock_analysis::analysis_and_position;
@@ -102,4 +113,32 @@ mod tests {
             "Foo STRUCT_DEF FileId(1) [52; 65) [59; 62)",
         );
     }
+
+    #[test]
+    fn goto_type_definition_for_param() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            fn foo(<|>f: Foo) {}
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+    }
+
+    #[test]
+    fn goto_type_definition_for_tuple_field() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            struct Bar(Foo);
+            fn foo() {
+                let bar = Bar(Foo);
+                bar.<|>0;
+            }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+    }
 }
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index 260a7b869..35e39f965 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -6,14 +6,13 @@ use ra_syntax::{
     algo::find_covering_element,
     ast::{self, DocCommentsOwner},
     match_ast, AstNode,
+    SyntaxKind::*,
+    SyntaxToken, TokenAtOffset,
 };
 
 use crate::{
     db::RootDatabase,
-    display::{
-        description_from_symbol, docs_from_symbol, macro_label, rust_code_markup,
-        rust_code_markup_with_doc, ShortLabel,
-    },
+    display::{macro_label, rust_code_markup, rust_code_markup_with_doc, ShortLabel},
     expand::descend_into_macros,
     references::{classify_name, classify_name_ref, NameKind, NameKind::*},
     FilePosition, FileRange, RangeInfo,
@@ -93,11 +92,7 @@ fn hover_text(docs: Option<String>, desc: Option<String>) -> Option<String> {
     }
 }
 
-fn hover_text_from_name_kind(
-    db: &RootDatabase,
-    name_kind: NameKind,
-    no_fallback: &mut bool,
-) -> Option<String> {
+fn hover_text_from_name_kind(db: &RootDatabase, name_kind: NameKind) -> Option<String> {
     return match name_kind {
         Macro(it) => {
             let src = it.source(db);
@@ -133,12 +128,8 @@ fn hover_text_from_name_kind(
             hir::ModuleDef::TypeAlias(it) => from_def_source(db, it),
             hir::ModuleDef::BuiltinType(it) => Some(it.to_string()),
         },
-        Local(_) => {
-            // Hover for these shows type names
-            *no_fallback = true;
-            None
-        }
-        GenericParam(_) | SelfType(_) => {
+        Local(_) => None,
+        TypeParam(_) | SelfType(_) => {
             // FIXME: Hover for generic param
             None
         }
@@ -156,68 +147,55 @@ fn hover_text_from_name_kind(
 
 pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo<HoverResult>> {
     let file = db.parse_or_expand(position.file_id.into())?;
-    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
+    let token = pick_best(file.token_at_offset(position.offset))?;
     let token = descend_into_macros(db, position.file_id, token);
 
     let mut res = HoverResult::new();
 
-    let mut range = match_ast! {
+    if let Some((range, name_kind)) = match_ast! {
         match (token.value.parent()) {
             ast::NameRef(name_ref) => {
-                let mut no_fallback = false;
-                if let Some(name_kind) =
-                    classify_name_ref(db, token.with_value(&name_ref)).map(|d| d.kind)
-                {
-                    res.extend(hover_text_from_name_kind(db, name_kind, &mut no_fallback))
-                }
-
-                if res.is_empty() && !no_fallback {
-                    // Fallback index based approach:
-                    let symbols = crate::symbol_index::index_resolve(db, &name_ref);
-                    for sym in symbols {
-                        let docs = docs_from_symbol(db, &sym);
-                        let desc = description_from_symbol(db, &sym);
-                        res.extend(hover_text(docs, desc));
-                    }
-                }
-
-                if !res.is_empty() {
-                    Some(name_ref.syntax().text_range())
-                } else {
-                    None
-                }
+                classify_name_ref(db, token.with_value(&name_ref)).map(|d| (name_ref.syntax().text_range(), d.kind))
             },
             ast::Name(name) => {
-                if let Some(name_kind) = classify_name(db, token.with_value(&name)).map(|d| d.kind) {
-                    res.extend(hover_text_from_name_kind(db, name_kind, &mut true));
-                }
-
-                if !res.is_empty() {
-                    Some(name.syntax().text_range())
-                } else {
-                    None
-                }
+                classify_name(db, token.with_value(&name)).map(|d| (name.syntax().text_range(), d.kind))
             },
             _ => None,
         }
-    };
+    } {
+        res.extend(hover_text_from_name_kind(db, name_kind));
 
-    if range.is_none() {
-        let node = token.value.ancestors().find(|n| {
-            ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some()
-        })?;
-        let frange = FileRange { file_id: position.file_id, range: node.text_range() };
-        res.extend(type_of(db, frange).map(rust_code_markup));
-        range = Some(node.text_range());
-    };
+        if !res.is_empty() {
+            return Some(RangeInfo::new(range, res));
+        }
+    }
 
-    let range = range?;
+    let node = token
+        .value
+        .ancestors()
+        .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())?;
+    let frange = FileRange { file_id: position.file_id, range: node.text_range() };
+    res.extend(type_of(db, frange).map(rust_code_markup));
     if res.is_empty() {
         return None;
     }
+    let range = node.text_range();
+
     Some(RangeInfo::new(range, res))
 }
 
+fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
+    return tokens.max_by_key(priority);
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            IDENT | INT_NUMBER => 3,
+            L_PAREN | R_PAREN => 2,
+            kind if kind.is_trivia() => 0,
+            _ => 1,
+        }
+    }
+}
+
 pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
     let parse = db.parse(frange.file_id);
     let leaf_node = find_covering_element(parse.tree().syntax(), frange.range);
@@ -227,7 +205,7 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
         .take_while(|it| it.text_range() == leaf_node.text_range())
         .find(|it| ast::Expr::cast(it.clone()).is_some() || ast::Pat::cast(it.clone()).is_some())?;
     let analyzer =
-        hir::SourceAnalyzer::new(db, hir::Source::new(frange.file_id.into(), &node), None);
+        hir::SourceAnalyzer::new(db, hir::InFile::new(frange.file_id.into(), &node), None);
     let ty = if let Some(ty) = ast::Expr::cast(node.clone()).and_then(|e| analyzer.type_of(db, &e))
     {
         ty
@@ -236,7 +214,7 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
     } else {
         return None;
     };
-    Some(ty.display(db).to_string())
+    Some(ty.display_truncated(db, None).to_string())
 }
 
 #[cfg(test)]
@@ -300,7 +278,7 @@ mod tests {
             &["pub fn foo() -> u32"],
         );
 
-        // Multiple results
+        // Multiple candidates but results are ambiguous.
         check_hover_result(
             r#"
             //- /a.rs
@@ -321,7 +299,7 @@ mod tests {
                 let foo_test = fo<|>o();
             }
         "#,
-            &["pub fn foo() -> &str", "pub fn foo() -> u32", "pub fn foo(a: u32, b: u32)"],
+            &["{unknown}"],
         );
     }
 
@@ -411,6 +389,23 @@ mod tests {
     }
 
     #[test]
+    fn hover_omits_default_generic_types() {
+        check_hover_result(
+            r#"
+//- /main.rs
+struct Test<K, T = u8> {
+    k: K,
+    t: T,
+}
+
+fn main() {
+    let zz<|> = Test { t: 23, k: 33 };
+}"#,
+            &["Test<i32>"],
+        );
+    }
+
+    #[test]
     fn hover_some() {
         let (analysis, position) = single_file_with_position(
             "
@@ -505,6 +500,13 @@ fn func(foo: i32) { if true { <|>foo; }; }
     }
 
     #[test]
+    fn hover_for_param_edge() {
+        let (analysis, position) = single_file_with_position("fn func(<|>foo: i32) {}");
+        let hover = analysis.hover(position).unwrap().unwrap();
+        assert_eq!(trim_markup_opt(hover.info.first()), Some("i32"));
+    }
+
+    #[test]
     fn test_type_of_for_function() {
         let (analysis, range) = single_file_with_range(
             "
diff --git a/crates/ra_ide/src/impls.rs b/crates/ra_ide/src/impls.rs
index aa480e399..9b165ee2a 100644
--- a/crates/ra_ide/src/impls.rs
+++ b/crates/ra_ide/src/impls.rs
@@ -16,7 +16,7 @@ pub(crate) fn goto_implementation(
     let src = hir::ModuleSource::from_position(db, position);
     let module = hir::Module::from_definition(
         db,
-        hir::Source { file_id: position.file_id.into(), value: src },
+        hir::InFile { file_id: position.file_id.into(), value: src },
     )?;
 
     if let Some(nominal_def) = find_node_at_offset::<ast::NominalDef>(&syntax, position.offset) {
@@ -42,15 +42,15 @@ fn impls_for_def(
 ) -> Option<Vec<NavigationTarget>> {
     let ty = match node {
         ast::NominalDef::StructDef(def) => {
-            let src = hir::Source { file_id: position.file_id.into(), value: def.clone() };
+            let src = hir::InFile { file_id: position.file_id.into(), value: def.clone() };
             hir::Struct::from_source(db, src)?.ty(db)
         }
         ast::NominalDef::EnumDef(def) => {
-            let src = hir::Source { file_id: position.file_id.into(), value: def.clone() };
+            let src = hir::InFile { file_id: position.file_id.into(), value: def.clone() };
             hir::Enum::from_source(db, src)?.ty(db)
         }
         ast::NominalDef::UnionDef(def) => {
-            let src = hir::Source { file_id: position.file_id.into(), value: def.clone() };
+            let src = hir::InFile { file_id: position.file_id.into(), value: def.clone() };
             hir::Union::from_source(db, src)?.ty(db)
         }
     };
@@ -73,7 +73,7 @@ fn impls_for_trait(
     node: &ast::TraitDef,
     module: hir::Module,
 ) -> Option<Vec<NavigationTarget>> {
-    let src = hir::Source { file_id: position.file_id.into(), value: node.clone() };
+    let src = hir::InFile { file_id: position.file_id.into(), value: node.clone() };
     let tr = hir::Trait::from_source(db, src)?;
 
     let krate = module.krate();
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 45149bf0c..c5e406977 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -1,12 +1,15 @@
 //! FIXME: write short doc here
 
-use crate::{db::RootDatabase, FileId};
 use hir::{HirDisplay, SourceAnalyzer};
+use once_cell::unsync::Lazy;
+use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode, TypeAscriptionOwner},
     match_ast, SmolStr, SourceFile, SyntaxKind, SyntaxNode, TextRange,
 };
 
+use crate::{db::RootDatabase, FileId};
+
 #[derive(Debug, PartialEq, Eq)]
 pub enum InlayKind {
     TypeHint,
@@ -27,7 +30,7 @@ pub(crate) fn inlay_hints(
 ) -> Vec<InlayHint> {
     file.syntax()
         .descendants()
-        .map(|node| get_inlay_hints(db, file_id, &node, max_inlay_hint_length).unwrap_or_default())
+        .flat_map(|node| get_inlay_hints(db, file_id, &node, max_inlay_hint_length))
         .flatten()
         .collect()
 }
@@ -38,7 +41,9 @@ fn get_inlay_hints(
     node: &SyntaxNode,
     max_inlay_hint_length: Option<usize>,
 ) -> Option<Vec<InlayHint>> {
-    let analyzer = SourceAnalyzer::new(db, hir::Source::new(file_id.into(), node), None);
+    let _p = profile("get_inlay_hints");
+    let analyzer =
+        Lazy::new(|| SourceAnalyzer::new(db, hir::InFile::new(file_id.into(), node), None));
     match_ast! {
         match node {
             ast::LetStmt(it) => {
@@ -122,18 +127,11 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
 
     while let Some(maybe_leaf_pat) = pats_to_process.pop_front() {
         match &maybe_leaf_pat {
-            ast::Pat::BindPat(bind_pat) => {
-                if let Some(pat) = bind_pat.pat() {
-                    pats_to_process.push_back(pat);
-                } else {
-                    leaf_pats.push(maybe_leaf_pat);
-                }
-            }
-            ast::Pat::TuplePat(tuple_pat) => {
-                for arg_pat in tuple_pat.args() {
-                    pats_to_process.push_back(arg_pat);
-                }
-            }
+            ast::Pat::BindPat(bind_pat) => match bind_pat.pat() {
+                Some(pat) => pats_to_process.push_back(pat),
+                _ => leaf_pats.push(maybe_leaf_pat),
+            },
+            ast::Pat::TuplePat(tuple_pat) => pats_to_process.extend(tuple_pat.args()),
             ast::Pat::RecordPat(record_pat) => {
                 if let Some(pat_list) = record_pat.record_field_pat_list() {
                     pats_to_process.extend(
@@ -151,10 +149,9 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
                 }
             }
             ast::Pat::TupleStructPat(tuple_struct_pat) => {
-                for arg_pat in tuple_struct_pat.args() {
-                    pats_to_process.push_back(arg_pat);
-                }
+                pats_to_process.extend(tuple_struct_pat.args())
             }
+            ast::Pat::RefPat(ref_pat) => pats_to_process.extend(ref_pat.pat()),
             _ => (),
         }
     }
@@ -163,9 +160,36 @@ fn get_leaf_pats(root_pat: ast::Pat) -> Vec<ast::Pat> {
 
 #[cfg(test)]
 mod tests {
-    use crate::mock_analysis::single_file;
     use insta::assert_debug_snapshot;
 
+    use crate::mock_analysis::single_file;
+
+    #[test]
+    fn default_generic_types_should_not_be_displayed() {
+        let (analysis, file_id) = single_file(
+            r#"
+struct Test<K, T = u8> {
+    k: K,
+    t: T,
+}
+
+fn main() {
+    let zz = Test { t: 23, k: 33 };
+}"#,
+        );
+
+        assert_debug_snapshot!(analysis.inlay_hints(file_id, None).unwrap(), @r###"
+        [
+            InlayHint {
+                range: [69; 71),
+                kind: TypeHint,
+                label: "Test<i32>",
+            },
+        ]
+        "###
+        );
+    }
+
     #[test]
     fn let_statement() {
         let (analysis, file_id) = single_file(
@@ -202,6 +226,7 @@ fn main() {
 
     let test = (42, 'a');
     let (a, (b, c, (d, e), f)) = (2, (3, 4, (6.6, 7.7), 5));
+    let &x = &92;
 }"#,
         );
 
@@ -257,6 +282,11 @@ fn main() {
                 kind: TypeHint,
                 label: "f64",
             },
+            InlayHint {
+                range: [627; 628),
+                kind: TypeHint,
+                label: "i32",
+            },
         ]
         "###
         );
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index d1bff4a76..779a81b2c 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -422,6 +422,11 @@ impl Analysis {
         self.with_db(|db| parent_module::crate_for(db, file_id))
     }
 
+    /// Returns the edition of the given crate.
+    pub fn crate_edition(&self, crate_id: CrateId) -> Cancelable<Edition> {
+        self.with_db(|db| db.crate_graph().edition(crate_id))
+    }
+
     /// Returns the root file of the given crate.
     pub fn crate_root(&self, crate_id: CrateId) -> Cancelable<FileId> {
         self.with_db(|db| db.crate_graph().crate_root(crate_id))
diff --git a/crates/ra_ide/src/marks.rs b/crates/ra_ide/src/marks.rs
index 848ae4dc7..077a44473 100644
--- a/crates/ra_ide/src/marks.rs
+++ b/crates/ra_ide/src/marks.rs
@@ -3,10 +3,11 @@
 test_utils::marks!(
     inserts_angle_brackets_for_generics
     inserts_parens_for_function_calls
-    goto_definition_works_for_macros
-    goto_definition_works_for_methods
-    goto_definition_works_for_fields
-    goto_definition_works_for_record_fields
+    goto_def_for_macros
+    goto_def_for_methods
+    goto_def_for_fields
+    goto_def_for_record_fields
+    goto_def_for_field_init_shorthand
     call_info_bad_offset
     dont_complete_current_use
     dont_complete_primitive_in_use
diff --git a/crates/ra_ide/src/parent_module.rs b/crates/ra_ide/src/parent_module.rs
index 6027e7d54..f5a788c07 100644
--- a/crates/ra_ide/src/parent_module.rs
+++ b/crates/ra_ide/src/parent_module.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use ra_db::{CrateId, FileId, FilePosition};
+use ra_db::{CrateId, FileId, FilePosition, SourceDatabase};
 
 use crate::{db::RootDatabase, NavigationTarget};
 
@@ -10,7 +10,7 @@ pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<Na
     let src = hir::ModuleSource::from_position(db, position);
     let module = match hir::Module::from_definition(
         db,
-        hir::Source { file_id: position.file_id.into(), value: src },
+        hir::InFile { file_id: position.file_id.into(), value: src },
     ) {
         None => return Vec::new(),
         Some(it) => it,
@@ -21,15 +21,16 @@ pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<Na
 
 /// Returns `Vec` for the same reason as `parent_module`
 pub(crate) fn crate_for(db: &RootDatabase, file_id: FileId) -> Vec<CrateId> {
-    let src = hir::ModuleSource::from_file_id(db, file_id);
+    let source_file = db.parse(file_id).tree();
+    let src = hir::ModuleSource::SourceFile(source_file);
     let module =
-        match hir::Module::from_definition(db, hir::Source { file_id: file_id.into(), value: src })
+        match hir::Module::from_definition(db, hir::InFile { file_id: file_id.into(), value: src })
         {
             Some(it) => it,
             None => return Vec::new(),
         };
     let krate = module.krate();
-    vec![krate.crate_id()]
+    vec![krate.into()]
 }
 
 #[cfg(test)]
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index 21a1ea69e..e3ecde50d 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -14,7 +14,7 @@ mod name_definition;
 mod rename;
 mod search_scope;
 
-use hir::Source;
+use hir::InFile;
 use once_cell::unsync::Lazy;
 use ra_db::{SourceDatabase, SourceDatabaseExt};
 use ra_prof::profile;
@@ -85,7 +85,7 @@ pub(crate) fn find_all_refs(
         NameKind::Def(def) => NavigationTarget::from_def(db, def)?,
         NameKind::SelfType(imp) => imp.to_nav(db),
         NameKind::Local(local) => local.to_nav(db),
-        NameKind::GenericParam(_) => return None,
+        NameKind::TypeParam(_) => return None,
     };
 
     let search_scope = {
@@ -107,12 +107,12 @@ fn find_name<'a>(
     position: FilePosition,
 ) -> Option<RangeInfo<(String, NameDefinition)>> {
     if let Some(name) = find_node_at_offset::<ast::Name>(&syntax, position.offset) {
-        let def = classify_name(db, Source::new(position.file_id.into(), &name))?;
+        let def = classify_name(db, InFile::new(position.file_id.into(), &name))?;
         let range = name.syntax().text_range();
         return Some(RangeInfo::new(range, (name.text().to_string(), def)));
     }
     let name_ref = find_node_at_offset::<ast::NameRef>(&syntax, position.offset)?;
-    let def = classify_name_ref(db, Source::new(position.file_id.into(), &name_ref))?;
+    let def = classify_name_ref(db, InFile::new(position.file_id.into(), &name_ref))?;
     let range = name_ref.syntax().text_range();
     Some(RangeInfo::new(range, (name_ref.text().to_string(), def)))
 }
@@ -144,7 +144,7 @@ fn process_definition(
                         continue;
                     }
                 }
-                if let Some(d) = classify_name_ref(db, Source::new(file_id.into(), &name_ref)) {
+                if let Some(d) = classify_name_ref(db, InFile::new(file_id.into(), &name_ref)) {
                     if d == def {
                         refs.push(FileRange { file_id, range });
                     }
diff --git a/crates/ra_ide/src/references/classify.rs b/crates/ra_ide/src/references/classify.rs
index 5cea805ec..3483a7176 100644
--- a/crates/ra_ide/src/references/classify.rs
+++ b/crates/ra_ide/src/references/classify.rs
@@ -1,6 +1,6 @@
 //! Functions that are used to classify an element from its definition or reference.
 
-use hir::{FromSource, Module, ModuleSource, PathResolution, Source, SourceAnalyzer};
+use hir::{FromSource, InFile, Module, ModuleSource, PathResolution, SourceAnalyzer};
 use ra_prof::profile;
 use ra_syntax::{ast, match_ast, AstNode};
 use test_utils::tested_by;
@@ -11,7 +11,7 @@ use super::{
 };
 use crate::db::RootDatabase;
 
-pub(crate) fn classify_name(db: &RootDatabase, name: Source<&ast::Name>) -> Option<NameDefinition> {
+pub(crate) fn classify_name(db: &RootDatabase, name: InFile<&ast::Name>) -> Option<NameDefinition> {
     let _p = profile("classify_name");
     let parent = name.value.syntax().parent()?;
 
@@ -110,6 +110,15 @@ pub(crate) fn classify_name(db: &RootDatabase, name: Source<&ast::Name>) -> Opti
                     kind: NameKind::Macro(def),
                 })
             },
+            ast::TypeParam(it) => {
+                let src = name.with_value(it);
+                let def = hir::TypeParam::from_source(db, src)?;
+                Some(NameDefinition {
+                    visibility: None,
+                    container: def.module(db),
+                    kind: NameKind::TypeParam(def),
+                })
+            },
             _ => None,
         }
     }
@@ -117,7 +126,7 @@ pub(crate) fn classify_name(db: &RootDatabase, name: Source<&ast::Name>) -> Opti
 
 pub(crate) fn classify_name_ref(
     db: &RootDatabase,
-    name_ref: Source<&ast::NameRef>,
+    name_ref: InFile<&ast::NameRef>,
 ) -> Option<NameDefinition> {
     let _p = profile("classify_name_ref");
 
@@ -125,21 +134,22 @@ pub(crate) fn classify_name_ref(
     let analyzer = SourceAnalyzer::new(db, name_ref.map(|it| it.syntax()), None);
 
     if let Some(method_call) = ast::MethodCallExpr::cast(parent.clone()) {
-        tested_by!(goto_definition_works_for_methods);
+        tested_by!(goto_def_for_methods);
         if let Some(func) = analyzer.resolve_method_call(&method_call) {
             return Some(from_assoc_item(db, func.into()));
         }
     }
 
     if let Some(field_expr) = ast::FieldExpr::cast(parent.clone()) {
-        tested_by!(goto_definition_works_for_fields);
+        tested_by!(goto_def_for_fields);
         if let Some(field) = analyzer.resolve_field(&field_expr) {
             return Some(from_struct_field(db, field));
         }
     }
 
     if let Some(record_field) = ast::RecordField::cast(parent.clone()) {
-        tested_by!(goto_definition_works_for_record_fields);
+        tested_by!(goto_def_for_record_fields);
+        tested_by!(goto_def_for_field_init_shorthand);
         if let Some(field_def) = analyzer.resolve_record_field(&record_field) {
             return Some(from_struct_field(db, field_def));
         }
@@ -151,7 +161,7 @@ pub(crate) fn classify_name_ref(
     let visibility = None;
 
     if let Some(macro_call) = parent.ancestors().find_map(ast::MacroCall::cast) {
-        tested_by!(goto_definition_works_for_macros);
+        tested_by!(goto_def_for_macros);
         if let Some(macro_def) = analyzer.resolve_macro_call(db, name_ref.with_value(&macro_call)) {
             let kind = NameKind::Macro(macro_def);
             return Some(NameDefinition { kind, container, visibility });
@@ -168,9 +178,8 @@ pub(crate) fn classify_name_ref(
             let kind = NameKind::Local(local);
             Some(NameDefinition { kind, container, visibility: None })
         }
-        PathResolution::GenericParam(par) => {
-            // FIXME: get generic param def
-            let kind = NameKind::GenericParam(par);
+        PathResolution::TypeParam(par) => {
+            let kind = NameKind::TypeParam(par);
             Some(NameDefinition { kind, container, visibility })
         }
         PathResolution::Macro(def) => {
diff --git a/crates/ra_ide/src/references/name_definition.rs b/crates/ra_ide/src/references/name_definition.rs
index 10d3a2364..8c67c8863 100644
--- a/crates/ra_ide/src/references/name_definition.rs
+++ b/crates/ra_ide/src/references/name_definition.rs
@@ -4,8 +4,8 @@
 //! Note that the reference search is possible for not all of the classified items.
 
 use hir::{
-    Adt, AssocItem, GenericParam, HasSource, ImplBlock, Local, MacroDef, Module, ModuleDef,
-    StructField, VariantDef,
+    Adt, AssocItem, HasSource, ImplBlock, Local, MacroDef, Module, ModuleDef, StructField,
+    TypeParam, VariantDef,
 };
 use ra_syntax::{ast, ast::VisibilityOwner};
 
@@ -19,7 +19,7 @@ pub enum NameKind {
     Def(ModuleDef),
     SelfType(ImplBlock),
     Local(Local),
-    GenericParam(GenericParam),
+    TypeParam(TypeParam),
 }
 
 #[derive(PartialEq, Eq)]
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index d58496049..b804d5f6d 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -2,7 +2,7 @@
 
 use hir::ModuleSource;
 use ra_db::{RelativePath, RelativePathBuf, SourceDatabase, SourceDatabaseExt};
-use ra_syntax::{algo::find_node_at_offset, ast, AstNode, SyntaxNode};
+use ra_syntax::{algo::find_node_at_offset, ast, tokenize, AstNode, SyntaxKind, SyntaxNode};
 use ra_text_edit::TextEdit;
 
 use crate::{
@@ -17,6 +17,13 @@ pub(crate) fn rename(
     position: FilePosition,
     new_name: &str,
 ) -> Option<RangeInfo<SourceChange>> {
+    let tokens = tokenize(new_name);
+    if tokens.len() != 1
+        || (tokens[0].kind != SyntaxKind::IDENT && tokens[0].kind != SyntaxKind::UNDERSCORE)
+    {
+        return None;
+    }
+
     let parse = db.parse(position.file_id);
     if let Some((ast_name, ast_module)) =
         find_name_and_module_at_offset(parse.tree().syntax(), position)
@@ -55,7 +62,7 @@ fn rename_mod(
 ) -> Option<SourceChange> {
     let mut source_file_edits = Vec::new();
     let mut file_system_edits = Vec::new();
-    let module_src = hir::Source { file_id: position.file_id.into(), value: ast_module.clone() };
+    let module_src = hir::InFile { file_id: position.file_id.into(), value: ast_module.clone() };
     if let Some(module) = hir::Module::from_declaration(db, module_src) {
         let src = module.definition_source(db);
         let file_id = src.file_id.original_file(db);
@@ -124,6 +131,49 @@ mod tests {
     };
 
     #[test]
+    fn test_rename_to_underscore() {
+        test_rename(
+            r#"
+    fn main() {
+        let i<|> = 1;
+    }"#,
+            "_",
+            r#"
+    fn main() {
+        let _ = 1;
+    }"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_to_raw_identifier() {
+        test_rename(
+            r#"
+    fn main() {
+        let i<|> = 1;
+    }"#,
+            "r#fn",
+            r#"
+    fn main() {
+        let r#fn = 1;
+    }"#,
+        );
+    }
+
+    #[test]
+    fn test_rename_to_invalid_identifier() {
+        let (analysis, position) = single_file_with_position(
+            "
+    fn main() {
+        let i<|> = 1;
+    }",
+        );
+        let new_name = "invalid!";
+        let source_change = analysis.rename(position, new_name).unwrap();
+        assert!(source_change.is_none());
+    }
+
+    #[test]
     fn test_rename_for_local() {
         test_rename(
             r#"
diff --git a/crates/ra_ide/src/references/search_scope.rs b/crates/ra_ide/src/references/search_scope.rs
index f5c9589f4..241dd358f 100644
--- a/crates/ra_ide/src/references/search_scope.rs
+++ b/crates/ra_ide/src/references/search_scope.rs
@@ -5,7 +5,7 @@
 use std::mem;
 
 use hir::{DefWithBody, HasSource, ModuleSource};
-use ra_db::{FileId, SourceDatabase, SourceDatabaseExt};
+use ra_db::{FileId, SourceDatabaseExt};
 use ra_prof::profile;
 use ra_syntax::{AstNode, TextRange};
 use rustc_hash::FxHashMap;
@@ -120,15 +120,11 @@ impl NameDefinition {
             }
             if vis.as_str() == "pub" {
                 let krate = self.container.krate();
-                let crate_graph = db.crate_graph();
-                for crate_id in crate_graph.iter() {
-                    let mut crate_deps = crate_graph.dependencies(crate_id);
-                    if crate_deps.any(|dep| dep.crate_id() == krate.crate_id()) {
-                        let root_file = crate_graph.crate_root(crate_id);
-                        let source_root_id = db.file_source_root(root_file);
-                        let source_root = db.source_root(source_root_id);
-                        res.extend(source_root.walk().map(|id| (id, None)));
-                    }
+                for rev_dep in krate.reverse_dependencies(db) {
+                    let root_file = rev_dep.root_file(db);
+                    let source_root_id = db.file_source_root(root_file);
+                    let source_root = db.source_root(source_root_id);
+                    res.extend(source_root.walk().map(|id| (id, None)));
                 }
                 return SearchScope::new(res);
             }
diff --git a/crates/ra_ide/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index 8039a5164..e213e1a06 100644
--- a/crates/ra_ide/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
@@ -1,6 +1,6 @@
 //! FIXME: write short doc here
 
-use hir::Source;
+use hir::InFile;
 use itertools::Itertools;
 use ra_db::SourceDatabase;
 use ra_syntax::{
@@ -66,8 +66,8 @@ fn runnable_mod(db: &RootDatabase, file_id: FileId, module: ast::Module) -> Opti
         return None;
     }
     let range = module.syntax().text_range();
-    let src = hir::ModuleSource::from_child_node(db, Source::new(file_id.into(), &module.syntax()));
-    let module = hir::Module::from_definition(db, Source::new(file_id.into(), src))?;
+    let src = hir::ModuleSource::from_child_node(db, InFile::new(file_id.into(), &module.syntax()));
+    let module = hir::Module::from_definition(db, InFile::new(file_id.into(), src))?;
 
     let path = module.path_to_root(db).into_iter().rev().filter_map(|it| it.name(db)).join("::");
     Some(Runnable { range, kind: RunnableKind::TestMod { path } })
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index b39c4d371..a097cf8e8 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -5,12 +5,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 
 .comment            { color: #7F9F7F; }
 .string             { color: #CC9393; }
+.field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .parameter          { color: #94BFF3; }
-.builtin            { color: #DD6718; }
 .text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.type\.builtin     { color: #8CD0D3; }
+.type\.param       { color: #20999D; }
 .attribute          { color: #94BFF3; }
 .literal            { color: #BFEBBF; }
+.literal\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
 .variable           { color: #DCDCCC; }
 .variable\.mut     { color: #DCDCCC; text-decoration: underline; }
@@ -21,28 +25,37 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 </style>
 <pre><code><span class="attribute">#</span><span class="attribute">[</span><span class="attribute">derive</span><span class="attribute">(</span><span class="attribute">Clone</span><span class="attribute">,</span><span class="attribute"> </span><span class="attribute">Debug</span><span class="attribute">)</span><span class="attribute">]</span>
 <span class="keyword">struct</span> <span class="type">Foo</span> {
-    <span class="keyword">pub</span> <span class="field">x</span>: <span class="type">i32</span>,
-    <span class="keyword">pub</span> <span class="field">y</span>: <span class="type">i32</span>,
+    <span class="keyword">pub</span> <span class="field">x</span>: <span class="type.builtin">i32</span>,
+    <span class="keyword">pub</span> <span class="field">y</span>: <span class="type.builtin">i32</span>,
 }
 
-<span class="keyword">fn</span> <span class="function">foo</span>&lt;<span class="type">T</span>&gt;() -&gt; <span class="type">T</span> {
+<span class="keyword">fn</span> <span class="function">foo</span>&lt;<span class="type.param">T</span>&gt;() -&gt; <span class="type.param">T</span> {
     <span class="macro">unimplemented</span><span class="macro">!</span>();
-    <span class="function">foo</span>::&lt;<span class="type">i32</span>&gt;();
+    <span class="function">foo</span>::&lt;<span class="type.builtin">i32</span>&gt;();
 }
 
 <span class="comment">// comment</span>
 <span class="keyword">fn</span> <span class="function">main</span>() {
-    <span class="macro">println</span><span class="macro">!</span>(<span class="string">"Hello, {}!"</span>, <span class="literal">92</span>);
+    <span class="macro">println</span><span class="macro">!</span>(<span class="string">"Hello, {}!"</span>, <span class="literal.numeric">92</span>);
 
     <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable.mut">vec</span> = <span class="text">Vec</span>::<span class="text">new</span>();
     <span class="keyword.control">if</span> <span class="keyword">true</span> {
-        <span class="variable.mut">vec</span>.<span class="text">push</span>(<span class="type">Foo</span> { <span class="field">x</span>: <span class="literal">0</span>, <span class="field">y</span>: <span class="literal">1</span> });
+        <span class="keyword">let</span> <span class="variable">x</span> = <span class="literal.numeric">92</span>;
+        <span class="variable.mut">vec</span>.<span class="text">push</span>(<span class="type">Foo</span> { <span class="field">x</span>, <span class="field">y</span>: <span class="literal.numeric">1</span> });
     }
-    <span class="keyword.unsafe">unsafe</span> { <span class="variable.mut">vec</span>.<span class="text">set_len</span>(<span class="literal">0</span>); }
+    <span class="keyword.unsafe">unsafe</span> { <span class="variable.mut">vec</span>.<span class="text">set_len</span>(<span class="literal.numeric">0</span>); }
 
-    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable.mut">x</span> = <span class="literal">42</span>;
+    <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable.mut">x</span> = <span class="literal.numeric">42</span>;
     <span class="keyword">let</span> <span class="variable.mut">y</span> = &<span class="keyword">mut</span> <span class="variable.mut">x</span>;
     <span class="keyword">let</span> <span class="variable">z</span> = &<span class="variable.mut">y</span>;
 
     <span class="variable.mut">y</span>;
+}
+
+<span class="keyword">enum</span> <span class="type">E</span>&lt;<span class="type.param">X</span>&gt; {
+    <span class="constant">V</span>(<span class="type.param">X</span>)
+}
+
+<span class="keyword">impl</span>&lt;<span class="type.param">X</span>&gt; <span class="type">E</span>&lt;<span class="type.param">X</span>&gt; {
+    <span class="keyword">fn</span> <span class="function">new</span>&lt;<span class="type.param">T</span>&gt;() -&gt; <span class="type">E</span>&lt;<span class="type.param">T</span>&gt; {}
 }</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index 79f11ea80..110556c09 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -5,12 +5,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 
 .comment            { color: #7F9F7F; }
 .string             { color: #CC9393; }
+.field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .parameter          { color: #94BFF3; }
-.builtin            { color: #DD6718; }
 .text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.type\.builtin     { color: #8CD0D3; }
+.type\.param       { color: #20999D; }
 .attribute          { color: #94BFF3; }
 .literal            { color: #BFEBBF; }
+.literal\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
 .variable           { color: #DCDCCC; }
 .variable\.mut     { color: #DCDCCC; text-decoration: underline; }
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 9a3e4c82f..0228ee7e9 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -2,7 +2,7 @@
 
 use rustc_hash::{FxHashMap, FxHashSet};
 
-use hir::{Name, Source};
+use hir::{InFile, Name};
 use ra_db::SourceDatabase;
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, Direction, SyntaxElement, SyntaxKind, SyntaxKind::*, TextRange, T};
@@ -16,6 +16,34 @@ use crate::{
     FileId,
 };
 
+pub mod tags {
+    pub(crate) const FIELD: &str = "field";
+    pub(crate) const FUNCTION: &str = "function";
+    pub(crate) const MODULE: &str = "module";
+    pub(crate) const TYPE: &str = "type";
+    pub(crate) const CONSTANT: &str = "constant";
+    pub(crate) const MACRO: &str = "macro";
+    pub(crate) const VARIABLE: &str = "variable";
+    pub(crate) const VARIABLE_MUT: &str = "variable.mut";
+    pub(crate) const TEXT: &str = "text";
+
+    pub(crate) const TYPE_BUILTIN: &str = "type.builtin";
+    pub(crate) const TYPE_SELF: &str = "type.self";
+    pub(crate) const TYPE_PARAM: &str = "type.param";
+    pub(crate) const TYPE_LIFETIME: &str = "type.lifetime";
+
+    pub(crate) const LITERAL_BYTE: &str = "literal.byte";
+    pub(crate) const LITERAL_NUMERIC: &str = "literal.numeric";
+    pub(crate) const LITERAL_CHAR: &str = "literal.char";
+    pub(crate) const LITERAL_COMMENT: &str = "comment";
+    pub(crate) const LITERAL_STRING: &str = "string";
+    pub(crate) const LITERAL_ATTRIBUTE: &str = "attribute";
+
+    pub(crate) const KEYWORD_UNSAFE: &str = "keyword.unsafe";
+    pub(crate) const KEYWORD_CONTROL: &str = "keyword.control";
+    pub(crate) const KEYWORD: &str = "keyword";
+}
+
 #[derive(Debug)]
 pub struct HighlightedRange {
     pub range: TextRange,
@@ -71,17 +99,16 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
                 bindings_shadow_count.clear();
                 continue;
             }
-            COMMENT => "comment",
-            STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => "string",
-            ATTR => "attribute",
+            COMMENT => tags::LITERAL_COMMENT,
+            STRING | RAW_STRING | RAW_BYTE_STRING | BYTE_STRING => tags::LITERAL_STRING,
+            ATTR => tags::LITERAL_ATTRIBUTE,
+            // Special-case field init shorthand
+            NAME_REF if node.parent().and_then(ast::RecordField::cast).is_some() => tags::FIELD,
+            NAME_REF if node.ancestors().any(|it| it.kind() == ATTR) => continue,
             NAME_REF => {
-                if node.ancestors().any(|it| it.kind() == ATTR) {
-                    continue;
-                }
-
                 let name_ref = node.as_node().cloned().and_then(ast::NameRef::cast).unwrap();
                 let name_kind =
-                    classify_name_ref(db, Source::new(file_id.into(), &name_ref)).map(|d| d.kind);
+                    classify_name_ref(db, InFile::new(file_id.into(), &name_ref)).map(|d| d.kind);
 
                 if let Some(Local(local)) = &name_kind {
                     if let Some(name) = local.name(db) {
@@ -90,12 +117,12 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
                     }
                 };
 
-                name_kind.map_or("text", |it| highlight_name(db, it))
+                name_kind.map_or(tags::TEXT, |it| highlight_name(db, it))
             }
             NAME => {
                 let name = node.as_node().cloned().and_then(ast::Name::cast).unwrap();
                 let name_kind =
-                    classify_name(db, Source::new(file_id.into(), &name)).map(|d| d.kind);
+                    classify_name(db, InFile::new(file_id.into(), &name)).map(|d| d.kind);
 
                 if let Some(Local(local)) = &name_kind {
                     if let Some(name) = local.name(db) {
@@ -107,18 +134,21 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
 
                 match name_kind {
                     Some(name_kind) => highlight_name(db, name_kind),
-                    None => name.syntax().parent().map_or("function", |x| match x.kind() {
-                        TYPE_PARAM | STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF => "type",
-                        RECORD_FIELD_DEF => "field",
-                        _ => "function",
+                    None => name.syntax().parent().map_or(tags::FUNCTION, |x| match x.kind() {
+                        STRUCT_DEF | ENUM_DEF | TRAIT_DEF | TYPE_ALIAS_DEF => tags::TYPE,
+                        TYPE_PARAM => tags::TYPE_PARAM,
+                        RECORD_FIELD_DEF => tags::FIELD,
+                        _ => tags::FUNCTION,
                     }),
                 }
             }
-            INT_NUMBER | FLOAT_NUMBER | CHAR | BYTE => "literal",
-            LIFETIME => "parameter",
-            T![unsafe] => "keyword.unsafe",
-            k if is_control_keyword(k) => "keyword.control",
-            k if k.is_keyword() => "keyword",
+            INT_NUMBER | FLOAT_NUMBER => tags::LITERAL_NUMERIC,
+            BYTE => tags::LITERAL_BYTE,
+            CHAR => tags::LITERAL_CHAR,
+            LIFETIME => tags::TYPE_LIFETIME,
+            T![unsafe] => tags::KEYWORD_UNSAFE,
+            k if is_control_keyword(k) => tags::KEYWORD_CONTROL,
+            k if k.is_keyword() => tags::KEYWORD,
             _ => {
                 if let Some(macro_call) = node.as_node().cloned().and_then(ast::MacroCall::cast) {
                     if let Some(path) = macro_call.path() {
@@ -135,7 +165,7 @@ pub(crate) fn highlight(db: &RootDatabase, file_id: FileId) -> Vec<HighlightedRa
                                 }
                                 res.push(HighlightedRange {
                                     range: TextRange::from_to(range_start, range_end),
-                                    tag: "macro",
+                                    tag: tags::MACRO,
                                     binding_hash: None,
                                 })
                             }
@@ -211,29 +241,27 @@ pub(crate) fn highlight_as_html(db: &RootDatabase, file_id: FileId, rainbow: boo
 
 fn highlight_name(db: &RootDatabase, name_kind: NameKind) -> &'static str {
     match name_kind {
-        Macro(_) => "macro",
-        Field(_) => "field",
-        AssocItem(hir::AssocItem::Function(_)) => "function",
-        AssocItem(hir::AssocItem::Const(_)) => "constant",
-        AssocItem(hir::AssocItem::TypeAlias(_)) => "type",
-        Def(hir::ModuleDef::Module(_)) => "module",
-        Def(hir::ModuleDef::Function(_)) => "function",
-        Def(hir::ModuleDef::Adt(_)) => "type",
-        Def(hir::ModuleDef::EnumVariant(_)) => "constant",
-        Def(hir::ModuleDef::Const(_)) => "constant",
-        Def(hir::ModuleDef::Static(_)) => "constant",
-        Def(hir::ModuleDef::Trait(_)) => "type",
-        Def(hir::ModuleDef::TypeAlias(_)) => "type",
-        Def(hir::ModuleDef::BuiltinType(_)) => "type",
-        SelfType(_) => "type",
-        GenericParam(_) => "type",
+        Macro(_) => tags::MACRO,
+        Field(_) => tags::FIELD,
+        AssocItem(hir::AssocItem::Function(_)) => tags::FUNCTION,
+        AssocItem(hir::AssocItem::Const(_)) => tags::CONSTANT,
+        AssocItem(hir::AssocItem::TypeAlias(_)) => tags::TYPE,
+        Def(hir::ModuleDef::Module(_)) => tags::MODULE,
+        Def(hir::ModuleDef::Function(_)) => tags::FUNCTION,
+        Def(hir::ModuleDef::Adt(_)) => tags::TYPE,
+        Def(hir::ModuleDef::EnumVariant(_)) => tags::CONSTANT,
+        Def(hir::ModuleDef::Const(_)) => tags::CONSTANT,
+        Def(hir::ModuleDef::Static(_)) => tags::CONSTANT,
+        Def(hir::ModuleDef::Trait(_)) => tags::TYPE,
+        Def(hir::ModuleDef::TypeAlias(_)) => tags::TYPE,
+        Def(hir::ModuleDef::BuiltinType(_)) => tags::TYPE_BUILTIN,
+        SelfType(_) => tags::TYPE_SELF,
+        TypeParam(_) => tags::TYPE_PARAM,
         Local(local) => {
-            if local.is_mut(db) {
-                "variable.mut"
-            } else if local.ty(db).is_mutable_reference() {
-                "variable.mut"
+            if local.is_mut(db) || local.ty(db).is_mutable_reference() {
+                tags::VARIABLE_MUT
             } else {
-                "variable"
+                tags::VARIABLE
             }
         }
     }
@@ -251,12 +279,16 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 
 .comment            { color: #7F9F7F; }
 .string             { color: #CC9393; }
+.field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
 .parameter          { color: #94BFF3; }
-.builtin            { color: #DD6718; }
 .text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.type\\.builtin     { color: #8CD0D3; }
+.type\\.param       { color: #20999D; }
 .attribute          { color: #94BFF3; }
 .literal            { color: #BFEBBF; }
+.literal\\.numeric  { color: #6A8759; }
 .macro              { color: #94BFF3; }
 .variable           { color: #DCDCCC; }
 .variable\\.mut     { color: #DCDCCC; text-decoration: underline; }
@@ -293,7 +325,8 @@ fn main() {
 
     let mut vec = Vec::new();
     if true {
-        vec.push(Foo { x: 0, y: 1 });
+        let x = 92;
+        vec.push(Foo { x, y: 1 });
     }
     unsafe { vec.set_len(0); }
 
@@ -303,6 +336,14 @@ fn main() {
 
     y;
 }
+
+enum E<X> {
+    V(X)
+}
+
+impl<X> E<X> {
+    fn new<T>() -> E<T> {}
+}
 "#
             .trim(),
         );
diff --git a/crates/ra_lsp_server/Cargo.toml b/crates/ra_lsp_server/Cargo.toml
index 21aef842c..60cbc38a9 100644
--- a/crates/ra_lsp_server/Cargo.toml
+++ b/crates/ra_lsp_server/Cargo.toml
@@ -13,9 +13,8 @@ relative-path = "1.0.0"
 serde_json = "1.0.34"
 serde = { version = "1.0.83", features = ["derive"] }
 crossbeam-channel = "0.4"
-flexi_logger = "0.14.0"
 log = "0.4.3"
-lsp-types = { version = "0.61.0", features = ["proposed"] }
+lsp-types = { version = "0.66.0", features = ["proposed"] }
 rustc-hash = "1.0"
 parking_lot = "0.10.0"
 jod-thread = "0.1.0"
@@ -27,6 +26,7 @@ lsp-server = "0.3.0"
 ra_project_model = { path = "../ra_project_model" }
 ra_prof = { path = "../ra_prof" }
 ra_vfs_glob = { path = "../ra_vfs_glob" }
+env_logger = { version = "0.7.1", default-features = false, features = ["humantime"] }
 
 [dev-dependencies]
 tempfile = "3"
diff --git a/crates/ra_lsp_server/build.rs b/crates/ra_lsp_server/build.rs
new file mode 100644
index 000000000..05f9772c0
--- /dev/null
+++ b/crates/ra_lsp_server/build.rs
@@ -0,0 +1,15 @@
+//! Just embed git-hash to `--version`
+
+use std::process::Command;
+
+fn main() {
+    let rev = rev().unwrap_or_else(|| "???????".to_string());
+    println!("cargo:rustc-env=REV={}", rev)
+}
+
+fn rev() -> Option<String> {
+    let output = Command::new("git").args(&["rev-parse", "HEAD"]).output().ok()?;
+    let stdout = String::from_utf8(output.stdout).ok()?;
+    let short_hash = stdout.get(0..7)?;
+    Some(short_hash.to_owned())
+}
diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index eea0965ed..eeca67ee1 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -1,11 +1,12 @@
-//! FIXME: write short doc here
+//! Advertizes the capabilities of the LSP Server.
 
 use lsp_types::{
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
-    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability, GenericCapability,
-    ImplementationProviderCapability, RenameOptions, RenameProviderCapability, ServerCapabilities,
-    SignatureHelpOptions, TextDocumentSyncCapability, TextDocumentSyncKind,
-    TextDocumentSyncOptions, TypeDefinitionProviderCapability,
+    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability,
+    ImplementationProviderCapability, RenameOptions, RenameProviderCapability,
+    SelectionRangeProviderCapability, ServerCapabilities, SignatureHelpOptions,
+    TextDocumentSyncCapability, TextDocumentSyncKind, TextDocumentSyncOptions,
+    TypeDefinitionProviderCapability, WorkDoneProgressOptions,
 };
 
 pub fn server_capabilities() -> ServerCapabilities {
@@ -21,10 +22,14 @@ pub fn server_capabilities() -> ServerCapabilities {
         completion_provider: Some(CompletionOptions {
             resolve_provider: None,
             trigger_characters: Some(vec![":".to_string(), ".".to_string()]),
+            work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None },
         }),
         signature_help_provider: Some(SignatureHelpOptions {
-            trigger_characters: Some(vec!["(".to_string(), ",".to_string(), ")".to_string()]),
+            trigger_characters: Some(vec!["(".to_string(), ",".to_string()]),
+            retrigger_characters: None,
+            work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None },
         }),
+        declaration_provider: None,
         definition_provider: Some(true),
         type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
         implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
@@ -40,10 +45,11 @@ pub fn server_capabilities() -> ServerCapabilities {
             first_trigger_character: "=".to_string(),
             more_trigger_character: Some(vec![".".to_string(), ">".to_string()]),
         }),
-        selection_range_provider: Some(GenericCapability::default()),
+        selection_range_provider: Some(SelectionRangeProviderCapability::Simple(true)),
         folding_range_provider: Some(FoldingRangeProviderCapability::Simple(true)),
         rename_provider: Some(RenameProviderCapability::Options(RenameOptions {
             prepare_provider: Some(true),
+            work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None },
         })),
         document_link_provider: None,
         color_provider: None,
diff --git a/crates/ra_lsp_server/src/config.rs b/crates/ra_lsp_server/src/config.rs
index 8045f3d60..67942aa41 100644
--- a/crates/ra_lsp_server/src/config.rs
+++ b/crates/ra_lsp_server/src/config.rs
@@ -9,6 +9,7 @@
 
 use rustc_hash::FxHashMap;
 
+use ra_project_model::CargoFeatures;
 use serde::{Deserialize, Deserializer};
 
 /// Client provided initialization options
@@ -37,6 +38,9 @@ pub struct ServerConfig {
 
     /// Fine grained feature flags to disable specific features.
     pub feature_flags: FxHashMap<String, bool>,
+
+    /// Cargo feature configurations.
+    pub cargo_features: CargoFeatures,
 }
 
 impl Default for ServerConfig {
@@ -49,6 +53,7 @@ impl Default for ServerConfig {
             max_inlay_hint_length: None,
             with_sysroot: true,
             feature_flags: FxHashMap::default(),
+            cargo_features: Default::default(),
         }
     }
 }
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index b13093cfe..e93d4ea33 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Convenience module responsible for translating between rust-analyzer's types and LSP types.
 
 use lsp_types::{
     self, CreateFile, DiagnosticSeverity, DocumentChangeOperation, DocumentChanges, Documentation,
@@ -130,6 +130,11 @@ impl ConvWith<(&LineIndex, LineEndings)> for CompletionItem {
             deprecated: Some(self.deprecated()),
             ..Default::default()
         };
+
+        if self.deprecated() {
+            res.tags = Some(vec![lsp_types::CompletionItemTag::Deprecated])
+        }
+
         res.insert_text_format = Some(match self.insert_text_format() {
             InsertTextFormat::Snippet => lsp_types::InsertTextFormat::Snippet,
             InsertTextFormat::PlainText => lsp_types::InsertTextFormat::PlainText,
diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index e13c8ca14..cdd925c9f 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -1,24 +1,22 @@
 //! `ra_lsp_server` binary
 
-use flexi_logger::{Duplicate, Logger};
 use lsp_server::Connection;
 use ra_lsp_server::{show_message, Result, ServerConfig};
 use ra_prof;
 
 fn main() -> Result<()> {
     setup_logging()?;
-    run_server()?;
+    match Args::parse()? {
+        Args::Version => println!("rust-analyzer {}", env!("REV")),
+        Args::Run => run_server()?,
+    }
     Ok(())
 }
 
 fn setup_logging() -> Result<()> {
     std::env::set_var("RUST_BACKTRACE", "short");
 
-    let logger = Logger::with_env_or_str("error").duplicate_to_stderr(Duplicate::All);
-    match std::env::var("RA_LOG_DIR") {
-        Ok(ref v) if v == "1" => logger.log_to_file().directory("log").start()?,
-        _ => logger.start()?,
-    };
+    env_logger::try_init()?;
 
     ra_prof::set_filter(match std::env::var("RA_PROFILE") {
         Ok(spec) => ra_prof::Filter::from_spec(&spec),
@@ -27,6 +25,19 @@ fn setup_logging() -> Result<()> {
     Ok(())
 }
 
+enum Args {
+    Version,
+    Run,
+}
+
+impl Args {
+    fn parse() -> Result<Args> {
+        let res =
+            if std::env::args().any(|it| it == "--version") { Args::Version } else { Args::Run };
+        Ok(res)
+    }
+}
+
 fn run_server() -> Result<()> {
     log::info!("lifecycle: server started");
 
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 83845f1e0..dda318e43 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! The main loop of `ra_lsp_server` responsible for dispatching LSP requests/replies and
+//! notifications back to the client.
 
 mod handlers;
 mod subscriptions;
@@ -67,6 +68,7 @@ pub fn main_loop(
                 let workspace = ra_project_model::ProjectWorkspace::discover_with_sysroot(
                     ws_root.as_path(),
                     config.with_sysroot,
+                    &config.cargo_features,
                 );
                 match workspace {
                     Ok(workspace) => loaded_workspaces.push(workspace),
@@ -130,7 +132,7 @@ pub fn main_loop(
         let feature_flags = {
             let mut ff = FeatureFlags::default();
             for (flag, value) in config.feature_flags {
-                if let Err(_) = ff.set(flag.as_str(), value) {
+                if ff.set(flag.as_str(), value).is_err() {
                     log::error!("unknown feature flag: {:?}", flag);
                     show_message(
                         req::MessageType::Error,
@@ -303,7 +305,6 @@ fn loop_turn(
         log::info!("queued count = {}", queue_count);
     }
 
-    let mut state_changed = false;
     match event {
         Event::Task(task) => {
             on_task(task, &connection.sender, &mut loop_state.pending_requests, world_state);
@@ -311,7 +312,6 @@ fn loop_turn(
         }
         Event::Vfs(task) => {
             world_state.vfs.write().handle_task(task);
-            state_changed = true;
         }
         Event::Lib(lib) => {
             world_state.add_lib(lib);
@@ -336,7 +336,6 @@ fn loop_turn(
                     &mut loop_state.subscriptions,
                     not,
                 )?;
-                state_changed = true;
             }
             Message::Response(resp) => {
                 let removed = loop_state.pending_responses.remove(&resp.id);
@@ -347,7 +346,12 @@ fn loop_turn(
         },
     };
 
-    loop_state.pending_libraries.extend(world_state.process_changes());
+    let mut state_changed = false;
+    if let Some(changes) = world_state.process_changes() {
+        state_changed = true;
+        loop_state.pending_libraries.extend(changes);
+    }
+
     while loop_state.in_flight_libraries < MAX_IN_FLIGHT_LIBS
         && !loop_state.pending_libraries.is_empty()
     {
@@ -520,7 +524,8 @@ fn on_notification(
             if let Some(file_id) = state.vfs.write().remove_file_overlay(path.as_path()) {
                 subs.remove_sub(FileId(file_id.0));
             }
-            let params = req::PublishDiagnosticsParams { uri, diagnostics: Vec::new() };
+            let params =
+                req::PublishDiagnosticsParams { uri, diagnostics: Vec::new(), version: None };
             let not = notification_new::<req::PublishDiagnostics>(params);
             msg_sender.send(not.into()).unwrap();
             return Ok(());
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index c81fa7f67..39eb3df3e 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -1,4 +1,5 @@
-//! FIXME: write short doc here
+//! This module is responsible for implementing handlers for Lanuage Server Protocol.
+//! The majority of requests are fulfilled by calling into the `ra_ide` crate.
 
 use std::{fmt::Write as _, io::Write as _};
 
@@ -164,7 +165,7 @@ pub fn handle_on_type_formatting(
 
     // in `ra_ide`, the `on_type` invariant is that
     // `text.char_at(position) == typed_char`.
-    position.offset = position.offset - TextUnit::of_char('.');
+    position.offset -= TextUnit::of_char('.');
     let char_typed = params.ch.chars().next().unwrap_or('\0');
 
     // We have an assist that inserts ` ` after typing `->` in `fn foo() ->{`,
@@ -480,8 +481,6 @@ pub fn handle_prepare_rename(
     let _p = profile("handle_prepare_rename");
     let position = params.try_conv_with(&world)?;
 
-    // We support renaming references like handle_rename does.
-    // In the future we may want to reject the renaming of things like keywords here too.
     let optional_change = world.analysis().rename(position, "dummy")?;
     let range = match optional_change {
         None => return Ok(None),
@@ -557,12 +556,18 @@ pub fn handle_formatting(
     let _p = profile("handle_formatting");
     let file_id = params.text_document.try_conv_with(&world)?;
     let file = world.analysis().file_text(file_id)?;
+    let crate_ids = world.analysis().crate_for(file_id)?;
 
     let file_line_index = world.analysis().file_line_index(file_id)?;
     let end_position = TextUnit::of_str(&file).conv_with(&file_line_index);
 
     use std::process;
     let mut rustfmt = process::Command::new("rustfmt");
+    if let Some(&crate_id) = crate_ids.first() {
+        // Assume all crates are in the same edition
+        let edition = world.analysis().crate_edition(crate_id)?;
+        rustfmt.args(&["--edition", &edition.to_string()]);
+    }
     rustfmt.stdin(process::Stdio::piped()).stdout(process::Stdio::piped());
 
     if let Ok(path) = params.text_document.uri.to_file_path() {
@@ -644,6 +649,7 @@ pub fn handle_code_action(
             diagnostics: None,
             edit: None,
             command: Some(command),
+            is_preferred: None,
         };
         res.push(action.into());
     }
@@ -666,6 +672,7 @@ pub fn handle_code_action(
             diagnostics: None,
             edit: None,
             command: Some(command),
+            is_preferred: None,
         };
         res.push(action.into());
     }
@@ -824,9 +831,10 @@ pub fn publish_diagnostics(
             source: Some("rust-analyzer".to_string()),
             message: d.message,
             related_information: None,
+            tags: None,
         })
         .collect();
-    Ok(req::PublishDiagnosticsParams { uri, diagnostics })
+    Ok(req::PublishDiagnosticsParams { uri, diagnostics, version: None })
 }
 
 pub fn publish_decorations(
diff --git a/crates/ra_lsp_server/src/main_loop/pending_requests.rs b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
index e7ea7aa5b..2d2213464 100644
--- a/crates/ra_lsp_server/src/main_loop/pending_requests.rs
+++ b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Datastructures that keep track of inflight requests.
 
 use std::time::{Duration, Instant};
 
diff --git a/crates/ra_lsp_server/src/main_loop/subscriptions.rs b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
index 609b2adcc..b0bae90f5 100644
--- a/crates/ra_lsp_server/src/main_loop/subscriptions.rs
+++ b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Keeps track of file subscriptions.
 
 use ra_ide::FileId;
 use rustc_hash::FxHashSet;
diff --git a/crates/ra_lsp_server/src/markdown.rs b/crates/ra_lsp_server/src/markdown.rs
index f51fc4ade..76bef45cc 100644
--- a/crates/ra_lsp_server/src/markdown.rs
+++ b/crates/ra_lsp_server/src/markdown.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Transforms markdown
 
 pub(crate) fn format_docs(src: &str) -> String {
     let mut processed_lines = Vec::new();
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index 39361b7e8..b34e6f9b8 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! Defines `rust-analyzer` specific custom messages.
 
 use lsp_types::{Location, Position, Range, TextDocumentIdentifier, Url};
 use rustc_hash::FxHashMap;
@@ -10,8 +10,9 @@ pub use lsp_types::{
     DidChangeWatchedFilesParams, DidChangeWatchedFilesRegistrationOptions,
     DocumentOnTypeFormattingParams, DocumentSymbolParams, DocumentSymbolResponse,
     FileSystemWatcher, Hover, InitializeResult, MessageType, PublishDiagnosticsParams,
-    ReferenceParams, Registration, RegistrationParams, ShowMessageParams, SignatureHelp,
-    TextDocumentEdit, TextDocumentPositionParams, TextEdit, WorkspaceEdit, WorkspaceSymbolParams,
+    ReferenceParams, Registration, RegistrationParams, SelectionRange, SelectionRangeParams,
+    ShowMessageParams, SignatureHelp, TextDocumentEdit, TextDocumentPositionParams, TextEdit,
+    WorkspaceEdit, WorkspaceSymbolParams,
 };
 
 pub enum AnalyzerStatus {}
@@ -67,28 +68,6 @@ pub struct ExpandMacroParams {
     pub position: Option<Position>,
 }
 
-pub enum SelectionRangeRequest {}
-
-impl Request for SelectionRangeRequest {
-    type Params = SelectionRangeParams;
-    type Result = Vec<SelectionRange>;
-    const METHOD: &'static str = "textDocument/selectionRange";
-}
-
-#[derive(Deserialize, Debug)]
-#[serde(rename_all = "camelCase")]
-pub struct SelectionRangeParams {
-    pub text_document: TextDocumentIdentifier,
-    pub positions: Vec<Position>,
-}
-
-#[derive(Serialize, Debug)]
-#[serde(rename_all = "camelCase")]
-pub struct SelectionRange {
-    pub range: Range,
-    pub parent: Option<Box<SelectionRange>>,
-}
-
 pub enum FindMatchingBrace {}
 
 impl Request for FindMatchingBrace {
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 927449b45..79431e7e6 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -1,4 +1,7 @@
-//! FIXME: write short doc here
+//! The context or environment in which the language server functions.
+//! In our server implementation this is know as the `WorldState`.
+//!
+//! Each tick provides an immutable snapshot of the state as `WorldSnapshot`.
 
 use std::{
     path::{Path, PathBuf},
@@ -17,11 +20,13 @@ use ra_project_model::{get_rustc_cfg_options, ProjectWorkspace};
 use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
 use ra_vfs_glob::{Glob, RustPackageFilterBuilder};
 use relative_path::RelativePathBuf;
+use std::path::{Component, Prefix};
 
 use crate::{
     main_loop::pending_requests::{CompletedRequest, LatestRequests},
     LspError, Result,
 };
+use std::str::FromStr;
 
 #[derive(Debug, Clone)]
 pub struct Options {
@@ -140,10 +145,10 @@ impl WorldState {
     /// FIXME: better API here
     pub fn process_changes(
         &mut self,
-    ) -> Vec<(SourceRootId, Vec<(FileId, RelativePathBuf, Arc<String>)>)> {
+    ) -> Option<Vec<(SourceRootId, Vec<(FileId, RelativePathBuf, Arc<String>)>)>> {
         let changes = self.vfs.write().commit_changes();
         if changes.is_empty() {
-            return Vec::new();
+            return None;
         }
         let mut libs = Vec::new();
         let mut change = AnalysisChange::new();
@@ -177,7 +182,7 @@ impl WorldState {
             }
         }
         self.analysis_host.apply_change(change);
-        libs
+        Some(libs)
     }
 
     pub fn add_lib(&mut self, data: LibraryData) {
@@ -233,8 +238,8 @@ impl WorldSnapshot {
 
     pub fn file_id_to_uri(&self, id: FileId) -> Result<Url> {
         let path = self.vfs.read().file2path(VfsFile(id.0));
-        let url = Url::from_file_path(&path)
-            .map_err(|_| format!("can't convert path to url: {}", path.display()))?;
+        let url = url_from_path_with_drive_lowercasing(path)?;
+
         Ok(url)
     }
 
@@ -279,3 +284,61 @@ impl WorldSnapshot {
         self.analysis.feature_flags()
     }
 }
+
+/// Returns a `Url` object from a given path, will lowercase drive letters if present.
+/// This will only happen when processing windows paths.
+///
+/// When processing non-windows path, this is essentially the same as `Url::from_file_path`.
+fn url_from_path_with_drive_lowercasing(path: impl AsRef<Path>) -> Result<Url> {
+    let component_has_windows_drive = path.as_ref().components().any(|comp| {
+        if let Component::Prefix(c) = comp {
+            match c.kind() {
+                Prefix::Disk(_) | Prefix::VerbatimDisk(_) => return true,
+                _ => return false,
+            }
+        }
+        false
+    });
+
+    // VSCode expects drive letters to be lowercased, where rust will uppercase the drive letters.
+    if component_has_windows_drive {
+        let url_original = Url::from_file_path(&path)
+            .map_err(|_| format!("can't convert path to url: {}", path.as_ref().display()))?;
+
+        let drive_partition: Vec<&str> = url_original.as_str().rsplitn(2, ':').collect();
+
+        // There is a drive partition, but we never found a colon.
+        // This should not happen, but in this case we just pass it through.
+        if drive_partition.len() == 1 {
+            return Ok(url_original);
+        }
+
+        let joined = drive_partition[1].to_ascii_lowercase() + ":" + drive_partition[0];
+        let url = Url::from_str(&joined).expect("This came from a valid `Url`");
+
+        Ok(url)
+    } else {
+        Ok(Url::from_file_path(&path)
+            .map_err(|_| format!("can't convert path to url: {}", path.as_ref().display()))?)
+    }
+}
+
+// `Url` is not able to parse windows paths on unix machines.
+#[cfg(target_os = "windows")]
+#[cfg(test)]
+mod path_conversion_windows_tests {
+    use super::url_from_path_with_drive_lowercasing;
+    #[test]
+    fn test_lowercase_drive_letter_with_drive() {
+        let url = url_from_path_with_drive_lowercasing("C:\\Test").unwrap();
+
+        assert_eq!(url.to_string(), "file:///c:/Test");
+    }
+
+    #[test]
+    fn test_drive_without_colon_passthrough() {
+        let url = url_from_path_with_drive_lowercasing(r#"\\localhost\C$\my_dir"#).unwrap();
+
+        assert_eq!(url.to_string(), "file://localhost/C$/my_dir");
+    }
+}
diff --git a/crates/ra_lsp_server/tests/heavy_tests/main.rs b/crates/ra_lsp_server/tests/heavy_tests/main.rs
index 2ba82ab05..dff63a12d 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/main.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/main.rs
@@ -4,7 +4,8 @@ use std::{collections::HashMap, time::Instant};
 
 use lsp_types::{
     CodeActionContext, DidOpenTextDocumentParams, DocumentFormattingParams, FormattingOptions,
-    Position, Range, TextDocumentItem, TextDocumentPositionParams,
+    PartialResultParams, Position, Range, TextDocumentItem, TextDocumentPositionParams,
+    WorkDoneProgressParams,
 };
 use ra_lsp_server::req::{
     CodeActionParams, CodeActionRequest, Completion, CompletionParams, DidOpenTextDocument,
@@ -12,15 +13,19 @@ use ra_lsp_server::req::{
 };
 use serde_json::json;
 use tempfile::TempDir;
+use test_utils::skip_slow_tests;
 
 use crate::support::{project, Project};
 
-const LOG: &'static str = "";
 const PROFILE: &'static str = "";
 // const PROFILE: &'static str = "*@3>100";
 
 #[test]
 fn completes_items_from_standard_library() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let project_start = Instant::now();
     let server = Project::with_fixture(
         r#"
@@ -44,6 +49,8 @@ use std::collections::Spam;
             Position::new(0, 23),
         ),
         context: None,
+        partial_result_params: PartialResultParams::default(),
+        work_done_progress_params: WorkDoneProgressParams::default(),
     });
     assert!(format!("{}", res).contains("HashMap"));
     eprintln!("completion took {:?}", completion_start.elapsed());
@@ -51,6 +58,10 @@ use std::collections::Spam;
 
 #[test]
 fn test_runnables_no_project() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let server = project(
         r"
 //- lib.rs
@@ -100,6 +111,10 @@ fn foo() {
 
 #[test]
 fn test_runnables_project() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let code = r#"
 //- foo/Cargo.toml
 [package]
@@ -171,8 +186,13 @@ fn main() {}
 
 #[test]
 fn test_format_document() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let server = project(
         r#"
+//- Cargo.toml
 [package]
 name = "foo"
 version = "0.0.0"
@@ -194,8 +214,12 @@ pub use std::collections::HashMap;
             options: FormattingOptions {
                 tab_size: 4,
                 insert_spaces: false,
+                insert_final_newline: None,
+                trim_final_newlines: None,
+                trim_trailing_whitespace: None,
                 properties: HashMap::new(),
             },
+            work_done_progress_params: WorkDoneProgressParams::default(),
         },
         json!([
             {
@@ -221,7 +245,77 @@ pub use std::collections::HashMap;
 }
 
 #[test]
+fn test_format_document_2018() {
+    if skip_slow_tests() {
+        return;
+    }
+
+    let server = project(
+        r#"
+//- Cargo.toml
+[package]
+name = "foo"
+version = "0.0.0"
+edition = "2018"
+
+//- src/lib.rs
+mod bar;
+
+async fn test() {
+}
+
+fn main() {
+}
+
+pub use std::collections::HashMap;
+"#,
+    );
+    server.wait_until_workspace_is_loaded();
+
+    server.request::<Formatting>(
+        DocumentFormattingParams {
+            text_document: server.doc_id("src/lib.rs"),
+            options: FormattingOptions {
+                tab_size: 4,
+                insert_spaces: false,
+                properties: HashMap::new(),
+                insert_final_newline: None,
+                trim_final_newlines: None,
+                trim_trailing_whitespace: None,
+            },
+            work_done_progress_params: WorkDoneProgressParams::default(),
+        },
+        json!([
+            {
+                "newText": r#"mod bar;
+
+async fn test() {}
+
+fn main() {}
+
+pub use std::collections::HashMap;
+"#,
+                "range": {
+                    "end": {
+                        "character": 0,
+                        "line": 10
+                    },
+                    "start": {
+                        "character": 0,
+                        "line": 0
+                    }
+                }
+            }
+        ]),
+    );
+}
+
+#[test]
 fn test_missing_module_code_action() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let server = project(
         r#"
 //- Cargo.toml
@@ -242,6 +336,8 @@ fn main() {}
             text_document: server.doc_id("src/lib.rs"),
             range: Range::new(Position::new(0, 4), Position::new(0, 7)),
             context: empty_context(),
+            partial_result_params: PartialResultParams::default(),
+            work_done_progress_params: WorkDoneProgressParams::default(),
         },
         json!([
           {
@@ -273,6 +369,8 @@ fn main() {}
             text_document: server.doc_id("src/lib.rs"),
             range: Range::new(Position::new(2, 4), Position::new(2, 7)),
             context: empty_context(),
+            partial_result_params: PartialResultParams::default(),
+            work_done_progress_params: WorkDoneProgressParams::default(),
         },
         json!([]),
     );
@@ -280,6 +378,10 @@ fn main() {}
 
 #[test]
 fn test_missing_module_code_action_in_json_project() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let tmp_dir = TempDir::new().unwrap();
 
     let path = tmp_dir.path();
@@ -317,6 +419,8 @@ fn main() {{}}
             text_document: server.doc_id("src/lib.rs"),
             range: Range::new(Position::new(0, 4), Position::new(0, 7)),
             context: empty_context(),
+            partial_result_params: PartialResultParams::default(),
+            work_done_progress_params: WorkDoneProgressParams::default(),
         },
         json!([
           {
@@ -348,6 +452,8 @@ fn main() {{}}
             text_document: server.doc_id("src/lib.rs"),
             range: Range::new(Position::new(2, 4), Position::new(2, 7)),
             context: empty_context(),
+            partial_result_params: PartialResultParams::default(),
+            work_done_progress_params: WorkDoneProgressParams::default(),
         },
         json!([]),
     );
@@ -355,6 +461,10 @@ fn main() {{}}
 
 #[test]
 fn diagnostics_dont_block_typing() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let librs: String = (0..10).map(|i| format!("mod m{};", i)).collect();
     let libs: String = (0..10).map(|i| format!("//- src/m{}.rs\nfn foo() {{}}\n\n", i)).collect();
     let server = Project::with_fixture(&format!(
@@ -423,6 +533,10 @@ fn main() {{}}
 
 #[test]
 fn preserves_dos_line_endings() {
+    if skip_slow_tests() {
+        return;
+    }
+
     let server = Project::with_fixture(
         &"
 //- Cargo.toml
diff --git a/crates/ra_lsp_server/tests/heavy_tests/support.rs b/crates/ra_lsp_server/tests/heavy_tests/support.rs
index 86073b57d..d5ea52fa9 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/support.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/support.rs
@@ -7,7 +7,6 @@ use std::{
 };
 
 use crossbeam_channel::{after, select, Receiver};
-use flexi_logger::Logger;
 use lsp_server::{Connection, Message, Notification, Request};
 use lsp_types::{
     notification::{DidOpenTextDocument, Exit},
@@ -53,7 +52,7 @@ impl<'a> Project<'a> {
         let tmp_dir = self.tmp_dir.unwrap_or_else(|| TempDir::new().unwrap());
         static INIT: Once = Once::new();
         INIT.call_once(|| {
-            let _ = Logger::with_env_or_str(crate::LOG).start().unwrap();
+            let _ = env_logger::builder().is_test(true).try_init().unwrap();
             ra_prof::set_filter(if crate::PROFILE.is_empty() {
                 ra_prof::Filter::disabled()
             } else {
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index bbddebe67..2c6ae5658 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -67,7 +67,15 @@ impl Shift {
                 .token_trees
                 .iter()
                 .filter_map(|tt| match tt {
-                    tt::TokenTree::Subtree(subtree) => max_id(subtree),
+                    tt::TokenTree::Subtree(subtree) => {
+                        let tree_id = max_id(subtree);
+                        match subtree.delimiter {
+                            Some(it) if it.id != tt::TokenId::unspecified() => {
+                                Some(tree_id.map_or(it.id.0, |t| t.max(it.id.0)))
+                            }
+                            _ => tree_id,
+                        }
+                    }
                     tt::TokenTree::Leaf(tt::Leaf::Ident(ident))
                         if ident.id != tt::TokenId::unspecified() =>
                     {
@@ -85,9 +93,15 @@ impl Shift {
             match t {
                 tt::TokenTree::Leaf(leaf) => match leaf {
                     tt::Leaf::Ident(ident) => ident.id = self.shift(ident.id),
-                    _ => (),
+                    tt::Leaf::Punct(punct) => punct.id = self.shift(punct.id),
+                    tt::Leaf::Literal(lit) => lit.id = self.shift(lit.id),
                 },
-                tt::TokenTree::Subtree(tt) => self.shift_all(tt),
+                tt::TokenTree::Subtree(tt) => {
+                    if let Some(it) = tt.delimiter.as_mut() {
+                        it.id = self.shift(it.id);
+                    };
+                    self.shift_all(tt)
+                }
             }
         }
     }
@@ -104,6 +118,7 @@ impl Shift {
     }
 }
 
+#[derive(Debug, Eq, PartialEq)]
 pub enum Origin {
     Def,
     Call,
@@ -159,14 +174,14 @@ impl Rule {
             .expect_subtree()
             .map_err(|()| ParseError::Expected("expected subtree".to_string()))?
             .clone();
-        lhs.delimiter = tt::Delimiter::None;
+        lhs.delimiter = None;
         src.expect_char('=').map_err(|()| ParseError::Expected("expected `=`".to_string()))?;
         src.expect_char('>').map_err(|()| ParseError::Expected("expected `>`".to_string()))?;
         let mut rhs = src
             .expect_subtree()
             .map_err(|()| ParseError::Expected("expected subtree".to_string()))?
             .clone();
-        rhs.delimiter = tt::Delimiter::None;
+        rhs.delimiter = None;
         Ok(crate::Rule { lhs, rhs })
     }
 }
diff --git a/crates/ra_mbe/src/mbe_expander/matcher.rs b/crates/ra_mbe/src/mbe_expander/matcher.rs
index 33b9d483d..e36b5a412 100644
--- a/crates/ra_mbe/src/mbe_expander/matcher.rs
+++ b/crates/ra_mbe/src/mbe_expander/matcher.rs
@@ -16,7 +16,7 @@ impl Bindings {
     fn push_optional(&mut self, name: &SmolStr) {
         // FIXME: Do we have a better way to represent an empty token ?
         // Insert an empty subtree for empty token
-        let tt = tt::Subtree { delimiter: tt::Delimiter::None, token_trees: vec![] }.into();
+        let tt = tt::Subtree::default().into();
         self.inner.insert(name.clone(), Binding::Fragment(Fragment::Tokens(tt)));
     }
 
@@ -65,7 +65,7 @@ macro_rules! bail {
 }
 
 pub(super) fn match_(pattern: &tt::Subtree, src: &tt::Subtree) -> Result<Bindings, ExpandError> {
-    assert!(pattern.delimiter == tt::Delimiter::None);
+    assert!(pattern.delimiter == None);
 
     let mut res = Bindings::default();
     let mut src = TtIter::new(src);
@@ -106,7 +106,7 @@ fn match_subtree(
             }
             Op::TokenTree(tt::TokenTree::Subtree(lhs)) => {
                 let rhs = src.expect_subtree().map_err(|()| err!("expected subtree"))?;
-                if lhs.delimiter != rhs.delimiter {
+                if lhs.delimiter_kind() != rhs.delimiter_kind() {
                     bail!("mismatched delimiter")
                 }
                 let mut src = TtIter::new(rhs);
@@ -210,7 +210,7 @@ impl<'a> TtIter<'a> {
             0 => Err(()),
             1 => Ok(res[0].clone()),
             _ => Ok(tt::TokenTree::Subtree(tt::Subtree {
-                delimiter: tt::Delimiter::None,
+                delimiter: None,
                 token_trees: res.into_iter().cloned().collect(),
             })),
         }
diff --git a/crates/ra_mbe/src/mbe_expander/transcriber.rs b/crates/ra_mbe/src/mbe_expander/transcriber.rs
index ed094d5bb..eda66cd50 100644
--- a/crates/ra_mbe/src/mbe_expander/transcriber.rs
+++ b/crates/ra_mbe/src/mbe_expander/transcriber.rs
@@ -50,7 +50,7 @@ pub(super) fn transcribe(
     template: &tt::Subtree,
     bindings: &Bindings,
 ) -> Result<tt::Subtree, ExpandError> {
-    assert!(template.delimiter == tt::Delimiter::None);
+    assert!(template.delimiter == None);
     let mut ctx = ExpandCtx { bindings: &bindings, nesting: Vec::new(), var_expanded: false };
     expand_subtree(&mut ctx, template)
 }
@@ -106,9 +106,14 @@ fn expand_var(ctx: &mut ExpandCtx, v: &SmolStr) -> Result<Fragment, ExpandError>
         // ```
         // We just treat it a normal tokens
         let tt = tt::Subtree {
-            delimiter: tt::Delimiter::None,
+            delimiter: None,
             token_trees: vec![
-                tt::Leaf::from(tt::Punct { char: '$', spacing: tt::Spacing::Alone }).into(),
+                tt::Leaf::from(tt::Punct {
+                    char: '$',
+                    spacing: tt::Spacing::Alone,
+                    id: tt::TokenId::unspecified(),
+                })
+                .into(),
                 tt::Leaf::from(tt::Ident { text: v.clone(), id: tt::TokenId::unspecified() })
                     .into(),
             ],
@@ -147,7 +152,7 @@ fn expand_repeat(
     ctx.var_expanded = false;
 
     while let Ok(mut t) = expand_subtree(ctx, template) {
-        t.delimiter = tt::Delimiter::None;
+        t.delimiter = None;
         // if no var expanded in the child, we count it as a fail
         if !ctx.var_expanded {
             break;
@@ -212,7 +217,7 @@ fn expand_repeat(
 
     // Check if it is a single token subtree without any delimiter
     // e.g {Delimiter:None> ['>'] /Delimiter:None>}
-    let tt = tt::Subtree { delimiter: tt::Delimiter::None, token_trees: buf }.into();
+    let tt = tt::Subtree { delimiter: None, token_trees: buf }.into();
     Ok(Fragment::Tokens(tt))
 }
 
@@ -225,7 +230,7 @@ fn push_fragment(buf: &mut Vec<tt::TokenTree>, fragment: Fragment) {
 
 fn push_subtree(buf: &mut Vec<tt::TokenTree>, tt: tt::Subtree) {
     match tt.delimiter {
-        tt::Delimiter::None => buf.extend(tt.token_trees),
+        None => buf.extend(tt.token_trees),
         _ => buf.push(tt.into()),
     }
 }
diff --git a/crates/ra_mbe/src/subtree_source.rs b/crates/ra_mbe/src/subtree_source.rs
index 7ef45f6dc..b841c39d3 100644
--- a/crates/ra_mbe/src/subtree_source.rs
+++ b/crates/ra_mbe/src/subtree_source.rs
@@ -70,11 +70,11 @@ impl<'a> SubtreeTokenSource<'a> {
                     }
                     Some(tt::TokenTree::Subtree(subtree)) => {
                         self.cached_cursor.set(cursor.subtree().unwrap());
-                        cached.push(Some(convert_delim(subtree.delimiter, false)));
+                        cached.push(Some(convert_delim(subtree.delimiter_kind(), false)));
                     }
                     None => {
                         if let Some(subtree) = cursor.end() {
-                            cached.push(Some(convert_delim(subtree.delimiter, true)));
+                            cached.push(Some(convert_delim(subtree.delimiter_kind(), true)));
                             self.cached_cursor.set(cursor.bump());
                         }
                     }
@@ -114,12 +114,12 @@ impl<'a> TokenSource for SubtreeTokenSource<'a> {
     }
 }
 
-fn convert_delim(d: tt::Delimiter, closing: bool) -> TtToken {
+fn convert_delim(d: Option<tt::DelimiterKind>, closing: bool) -> TtToken {
     let (kinds, texts) = match d {
-        tt::Delimiter::Parenthesis => ([T!['('], T![')']], "()"),
-        tt::Delimiter::Brace => ([T!['{'], T!['}']], "{}"),
-        tt::Delimiter::Bracket => ([T!['['], T![']']], "[]"),
-        tt::Delimiter::None => ([L_DOLLAR, R_DOLLAR], ""),
+        Some(tt::DelimiterKind::Parenthesis) => ([T!['('], T![')']], "()"),
+        Some(tt::DelimiterKind::Brace) => ([T!['{'], T!['}']], "{}"),
+        Some(tt::DelimiterKind::Bracket) => ([T!['['], T![']']], "[]"),
+        None => ([L_DOLLAR, R_DOLLAR], ""),
     };
 
     let idx = closing as usize;
diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs
index 1de399fee..ea2cac069 100644
--- a/crates/ra_mbe/src/syntax_bridge.rs
+++ b/crates/ra_mbe/src/syntax_bridge.rs
@@ -2,25 +2,45 @@
 
 use ra_parser::{FragmentKind, ParseError, TreeSink};
 use ra_syntax::{
-    ast, AstNode, AstToken, NodeOrToken, Parse, SmolStr, SyntaxKind, SyntaxKind::*, SyntaxNode,
+    ast, AstToken, NodeOrToken, Parse, SmolStr, SyntaxKind, SyntaxKind::*, SyntaxNode,
     SyntaxTreeBuilder, TextRange, TextUnit, T,
 };
+use rustc_hash::FxHashMap;
 use std::iter::successors;
 use tt::buffer::{Cursor, TokenBuffer};
 
 use crate::subtree_source::SubtreeTokenSource;
 use crate::ExpandError;
 
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum TokenTextRange {
+    Token(TextRange),
+    Delimiter(TextRange, TextRange),
+}
+
+impl TokenTextRange {
+    pub fn by_kind(self, kind: SyntaxKind) -> Option<TextRange> {
+        match self {
+            TokenTextRange::Token(it) => Some(it),
+            TokenTextRange::Delimiter(open, close) => match kind {
+                T!['{'] | T!['('] | T!['['] => Some(open),
+                T!['}'] | T![')'] | T![']'] => Some(close),
+                _ => None,
+            },
+        }
+    }
+}
+
 /// Maps `tt::TokenId` to the relative range of the original token.
 #[derive(Debug, PartialEq, Eq, Default)]
 pub struct TokenMap {
     /// Maps `tt::TokenId` to the *relative* source range.
-    entries: Vec<(tt::TokenId, TextRange)>,
+    entries: Vec<(tt::TokenId, TokenTextRange)>,
 }
 
 /// Convert the syntax tree (what user has written) to a `TokenTree` (what macro
 /// will consume).
-pub fn ast_to_token_tree(ast: &ast::TokenTree) -> Option<(tt::Subtree, TokenMap)> {
+pub fn ast_to_token_tree(ast: &impl ast::AstNode) -> Option<(tt::Subtree, TokenMap)> {
     syntax_node_to_token_tree(ast.syntax())
 }
 
@@ -51,7 +71,7 @@ pub fn token_tree_to_syntax_node(
 ) -> Result<(Parse<SyntaxNode>, TokenMap), ExpandError> {
     let tmp;
     let tokens = match tt {
-        tt::Subtree { delimiter: tt::Delimiter::None, token_trees } => token_trees.as_slice(),
+        tt::Subtree { delimiter: None, token_trees } => token_trees.as_slice(),
         _ => {
             tmp = [tt.clone().into()];
             &tmp[..]
@@ -71,17 +91,32 @@ pub fn token_tree_to_syntax_node(
 
 impl TokenMap {
     pub fn token_by_range(&self, relative_range: TextRange) -> Option<tt::TokenId> {
-        let &(token_id, _) = self.entries.iter().find(|(_, range)| *range == relative_range)?;
+        let &(token_id, _) = self.entries.iter().find(|(_, range)| match range {
+            TokenTextRange::Token(it) => *it == relative_range,
+            TokenTextRange::Delimiter(open, close) => {
+                *open == relative_range || *close == relative_range
+            }
+        })?;
         Some(token_id)
     }
 
-    pub fn range_by_token(&self, token_id: tt::TokenId) -> Option<TextRange> {
+    pub fn range_by_token(&self, token_id: tt::TokenId) -> Option<TokenTextRange> {
         let &(_, range) = self.entries.iter().find(|(tid, _)| *tid == token_id)?;
         Some(range)
     }
 
     fn insert(&mut self, token_id: tt::TokenId, relative_range: TextRange) {
-        self.entries.push((token_id, relative_range));
+        self.entries.push((token_id, TokenTextRange::Token(relative_range)));
+    }
+
+    fn insert_delim(
+        &mut self,
+        token_id: tt::TokenId,
+        open_relative_range: TextRange,
+        close_relative_range: TextRange,
+    ) {
+        self.entries
+            .push((token_id, TokenTextRange::Delimiter(open_relative_range, close_relative_range)));
     }
 }
 
@@ -121,7 +156,10 @@ fn convert_doc_comment(token: &ra_syntax::SyntaxToken) -> Option<Vec<tt::TokenTr
         token_trees.push(mk_punct('!'));
     }
     token_trees.push(tt::TokenTree::from(tt::Subtree {
-        delimiter: tt::Delimiter::Bracket,
+        delimiter: Some(tt::Delimiter {
+            kind: tt::DelimiterKind::Bracket,
+            id: tt::TokenId::unspecified(),
+        }),
         token_trees: meta_tkns,
     }));
 
@@ -136,11 +174,15 @@ fn convert_doc_comment(token: &ra_syntax::SyntaxToken) -> Option<Vec<tt::TokenTr
     }
 
     fn mk_punct(c: char) -> tt::TokenTree {
-        tt::TokenTree::from(tt::Leaf::from(tt::Punct { char: c, spacing: tt::Spacing::Alone }))
+        tt::TokenTree::from(tt::Leaf::from(tt::Punct {
+            char: c,
+            spacing: tt::Spacing::Alone,
+            id: tt::TokenId::unspecified(),
+        }))
     }
 
     fn mk_doc_literal(comment: &ast::Comment) -> tt::TokenTree {
-        let lit = tt::Literal { text: doc_comment_text(comment) };
+        let lit = tt::Literal { text: doc_comment_text(comment), id: tt::TokenId::unspecified() };
 
         tt::TokenTree::from(tt::Leaf::from(lit))
     }
@@ -156,7 +198,7 @@ impl Convertor {
     fn go(&mut self, tt: &SyntaxNode) -> Option<tt::Subtree> {
         // This tree is empty
         if tt.first_child_or_token().is_none() {
-            return Some(tt::Subtree { token_trees: vec![], delimiter: tt::Delimiter::None });
+            return Some(tt::Subtree { token_trees: vec![], delimiter: None });
         }
 
         let first_child = tt.first_child_or_token()?;
@@ -173,7 +215,7 @@ impl Convertor {
         .last()
         .unwrap();
         if first_child.kind().is_trivia() {
-            return Some(tt::Subtree { token_trees: vec![], delimiter: tt::Delimiter::None });
+            return Some(tt::Subtree { token_trees: vec![], delimiter: None });
         }
 
         let last_child = successors(Some(last_child), |it| {
@@ -186,12 +228,16 @@ impl Convertor {
         .last()
         .unwrap();
 
-        let (delimiter, skip_first) = match (first_child.kind(), last_child.kind()) {
-            (T!['('], T![')']) => (tt::Delimiter::Parenthesis, true),
-            (T!['{'], T!['}']) => (tt::Delimiter::Brace, true),
-            (T!['['], T![']']) => (tt::Delimiter::Bracket, true),
-            _ => (tt::Delimiter::None, false),
+        let (delimiter_kind, skip_first) = match (first_child.kind(), last_child.kind()) {
+            (T!['('], T![')']) => (Some(tt::DelimiterKind::Parenthesis), true),
+            (T!['{'], T!['}']) => (Some(tt::DelimiterKind::Brace), true),
+            (T!['['], T![']']) => (Some(tt::DelimiterKind::Bracket), true),
+            _ => (None, false),
         };
+        let delimiter = delimiter_kind.map(|kind| tt::Delimiter {
+            kind,
+            id: self.alloc_delim(first_child.text_range(), last_child.text_range()),
+        });
 
         let mut token_trees = Vec::new();
         let mut child_iter = tt.children_with_tokens().skip(skip_first as usize).peekable();
@@ -208,13 +254,8 @@ impl Convertor {
                     } else if token.kind().is_trivia() {
                         continue;
                     } else if token.kind().is_punct() {
-                        assert!(
-                            token.text().len() == 1,
-                            "Input ast::token punct must be single char."
-                        );
-                        let char = token.text().chars().next().unwrap();
-
-                        let spacing = match child_iter.peek() {
+                        // we need to pull apart joined punctuation tokens
+                        let last_spacing = match child_iter.peek() {
                             Some(NodeOrToken::Token(token)) => {
                                 if token.kind().is_punct() {
                                     tt::Spacing::Joint
@@ -224,30 +265,47 @@ impl Convertor {
                             }
                             _ => tt::Spacing::Alone,
                         };
-
-                        token_trees.push(tt::Leaf::from(tt::Punct { char, spacing }).into());
+                        let spacing_iter = std::iter::repeat(tt::Spacing::Joint)
+                            .take(token.text().len() - 1)
+                            .chain(std::iter::once(last_spacing));
+                        for (char, spacing) in token.text().chars().zip(spacing_iter) {
+                            token_trees.push(
+                                tt::Leaf::from(tt::Punct {
+                                    char,
+                                    spacing,
+                                    id: self.alloc(token.text_range()),
+                                })
+                                .into(),
+                            );
+                        }
                     } else {
-                        let child: tt::TokenTree =
-                            if token.kind() == T![true] || token.kind() == T![false] {
-                                tt::Leaf::from(tt::Literal { text: token.text().clone() }).into()
-                            } else if token.kind().is_keyword()
-                                || token.kind() == IDENT
-                                || token.kind() == LIFETIME
-                            {
-                                let id = self.alloc(token.text_range());
-                                let text = token.text().clone();
-                                tt::Leaf::from(tt::Ident { text, id }).into()
-                            } else if token.kind().is_literal() {
-                                tt::Leaf::from(tt::Literal { text: token.text().clone() }).into()
-                            } else {
-                                return None;
+                        macro_rules! make_leaf {
+                            ($i:ident) => {
+                                tt::$i {
+                                    id: self.alloc(token.text_range()),
+                                    text: token.text().clone(),
+                                }
+                                .into()
                             };
-                        token_trees.push(child);
+                        }
+
+                        let child: tt::Leaf = match token.kind() {
+                            T![true] | T![false] => make_leaf!(Literal),
+                            IDENT | LIFETIME => make_leaf!(Ident),
+                            k if k.is_keyword() => make_leaf!(Ident),
+                            k if k.is_literal() => make_leaf!(Literal),
+                            _ => return None,
+                        };
+                        token_trees.push(child.into());
                     }
                 }
                 NodeOrToken::Node(node) => {
-                    let child = self.go(&node)?.into();
-                    token_trees.push(child);
+                    let child_subtree = self.go(&node)?;
+                    if child_subtree.delimiter.is_none() && node.kind() != SyntaxKind::TOKEN_TREE {
+                        token_trees.extend(child_subtree.token_trees);
+                    } else {
+                        token_trees.push(child_subtree.into());
+                    }
                 }
             };
         }
@@ -263,11 +321,26 @@ impl Convertor {
         self.map.insert(token_id, relative_range);
         token_id
     }
+
+    fn alloc_delim(
+        &mut self,
+        open_abs_range: TextRange,
+        close_abs_range: TextRange,
+    ) -> tt::TokenId {
+        let open_relative_range = open_abs_range - self.global_offset;
+        let close_relative_range = close_abs_range - self.global_offset;
+        let token_id = tt::TokenId(self.next_id);
+        self.next_id += 1;
+
+        self.map.insert_delim(token_id, open_relative_range, close_relative_range);
+        token_id
+    }
 }
 
 struct TtTreeSink<'a> {
     buf: String,
     cursor: Cursor<'a>,
+    open_delims: FxHashMap<tt::TokenId, TextUnit>,
     text_pos: TextUnit,
     inner: SyntaxTreeBuilder,
     token_map: TokenMap,
@@ -282,6 +355,7 @@ impl<'a> TtTreeSink<'a> {
         TtTreeSink {
             buf: String::new(),
             cursor,
+            open_delims: FxHashMap::default(),
             text_pos: 0.into(),
             inner: SyntaxTreeBuilder::default(),
             roots: smallvec::SmallVec::new(),
@@ -294,16 +368,16 @@ impl<'a> TtTreeSink<'a> {
     }
 }
 
-fn delim_to_str(d: tt::Delimiter, closing: bool) -> SmolStr {
+fn delim_to_str(d: Option<tt::DelimiterKind>, closing: bool) -> SmolStr {
     let texts = match d {
-        tt::Delimiter::Parenthesis => "()",
-        tt::Delimiter::Brace => "{}",
-        tt::Delimiter::Bracket => "[]",
-        tt::Delimiter::None => "",
+        Some(tt::DelimiterKind::Parenthesis) => "()",
+        Some(tt::DelimiterKind::Brace) => "{}",
+        Some(tt::DelimiterKind::Bracket) => "[]",
+        None => return "".into(),
     };
 
     let idx = closing as usize;
-    let text = if !texts.is_empty() { &texts[idx..texts.len() - (1 - idx)] } else { "" };
+    let text = &texts[idx..texts.len() - (1 - idx)];
     text.into()
 }
 
@@ -319,34 +393,49 @@ impl<'a> TreeSink for TtTreeSink<'a> {
                 break;
             }
 
-            match self.cursor.token_tree() {
+            let text: SmolStr = match self.cursor.token_tree() {
                 Some(tt::TokenTree::Leaf(leaf)) => {
                     // Mark the range if needed
-                    if let tt::Leaf::Ident(ident) = leaf {
-                        if kind == IDENT {
-                            let range =
-                                TextRange::offset_len(self.text_pos, TextUnit::of_str(&ident.text));
-                            self.token_map.insert(ident.id, range);
-                        }
-                    }
-
+                    let id = match leaf {
+                        tt::Leaf::Ident(ident) => ident.id,
+                        tt::Leaf::Punct(punct) => punct.id,
+                        tt::Leaf::Literal(lit) => lit.id,
+                    };
+                    let text = SmolStr::new(format!("{}", leaf));
+                    let range = TextRange::offset_len(self.text_pos, TextUnit::of_str(&text));
+                    self.token_map.insert(id, range);
                     self.cursor = self.cursor.bump();
-                    self.buf += &format!("{}", leaf);
+                    text
                 }
                 Some(tt::TokenTree::Subtree(subtree)) => {
                     self.cursor = self.cursor.subtree().unwrap();
-                    self.buf += &delim_to_str(subtree.delimiter, false);
+                    if let Some(id) = subtree.delimiter.map(|it| it.id) {
+                        self.open_delims.insert(id, self.text_pos);
+                    }
+                    delim_to_str(subtree.delimiter_kind(), false)
                 }
                 None => {
                     if let Some(parent) = self.cursor.end() {
                         self.cursor = self.cursor.bump();
-                        self.buf += &delim_to_str(parent.delimiter, true);
+                        if let Some(id) = parent.delimiter.map(|it| it.id) {
+                            if let Some(open_delim) = self.open_delims.get(&id) {
+                                let open_range =
+                                    TextRange::offset_len(*open_delim, TextUnit::from_usize(1));
+                                let close_range =
+                                    TextRange::offset_len(self.text_pos, TextUnit::from_usize(1));
+                                self.token_map.insert_delim(id, open_range, close_range);
+                            }
+                        }
+                        delim_to_str(parent.delimiter_kind(), true)
+                    } else {
+                        continue;
                     }
                 }
             };
+            self.buf += &text;
+            self.text_pos += TextUnit::of_str(&text);
         }
 
-        self.text_pos += TextUnit::of_str(&self.buf);
         let text = SmolStr::new(self.buf.as_str());
         self.buf.clear();
         self.inner.token(kind, text);
@@ -387,13 +476,16 @@ impl<'a> TreeSink for TtTreeSink<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::tests::{create_rules, expand};
+    use crate::tests::parse_macro;
     use ra_parser::TokenSource;
-    use ra_syntax::algo::{insert_children, InsertPosition};
+    use ra_syntax::{
+        algo::{insert_children, InsertPosition},
+        ast::AstNode,
+    };
 
     #[test]
     fn convert_tt_token_source() {
-        let rules = create_rules(
+        let expansion = parse_macro(
             r#"
             macro_rules! literals {
                 ($i:ident) => {
@@ -406,8 +498,8 @@ mod tests {
                 }
             }
             "#,
-        );
-        let expansion = expand(&rules, "literals!(foo);");
+        )
+        .expand_tt("literals!(foo);");
         let tts = &[expansion.into()];
         let buffer = tt::buffer::TokenBuffer::new(tts);
         let mut tt_src = SubtreeTokenSource::new(&buffer);
@@ -435,7 +527,7 @@ mod tests {
 
     #[test]
     fn stmts_token_trees_to_expr_is_err() {
-        let rules = create_rules(
+        let expansion = parse_macro(
             r#"
             macro_rules! stmts {
                 () => {
@@ -446,8 +538,8 @@ mod tests {
                 }
             }
             "#,
-        );
-        let expansion = expand(&rules, "stmts!();");
+        )
+        .expand_tt("stmts!();");
         assert!(token_tree_to_syntax_node(&expansion, FragmentKind::Expr).is_err());
     }
 
@@ -489,6 +581,14 @@ mod tests {
         let token_tree = ast::TokenTree::cast(token_tree).unwrap();
         let tt = ast_to_token_tree(&token_tree).unwrap().0;
 
-        assert_eq!(tt.delimiter, tt::Delimiter::Brace);
+        assert_eq!(tt.delimiter_kind(), Some(tt::DelimiterKind::Brace));
+    }
+
+    #[test]
+    fn test_token_tree_multi_char_punct() {
+        let source_file = ast::SourceFile::parse("struct Foo { a: x::Y }").ok().unwrap();
+        let struct_def = source_file.syntax().descendants().find_map(ast::StructDef::cast).unwrap();
+        let tt = ast_to_token_tree(&struct_def).unwrap().0;
+        token_tree_to_syntax_node(&tt, FragmentKind::Item).unwrap();
     }
 }
diff --git a/crates/ra_mbe/src/tests.rs b/crates/ra_mbe/src/tests.rs
index 0109a4d98..e640d115b 100644
--- a/crates/ra_mbe/src/tests.rs
+++ b/crates/ra_mbe/src/tests.rs
@@ -1,5 +1,7 @@
+use std::fmt::Write;
+
 use ra_parser::FragmentKind;
-use ra_syntax::{ast, AstNode, NodeOrToken, WalkEvent};
+use ra_syntax::{ast, AstNode, NodeOrToken, SyntaxKind::IDENT, SyntaxNode, WalkEvent, T};
 use test_utils::assert_eq_text;
 
 use super::*;
@@ -61,13 +63,14 @@ mod rule_parsing {
 
 #[test]
 fn test_token_id_shift() {
-    let macro_definition = r#"
+    let expansion = parse_macro(
+        r#"
 macro_rules! foobar {
     ($e:ident) => { foo bar $e }
 }
-"#;
-    let rules = create_rules(macro_definition);
-    let expansion = expand(&rules, "foobar!(baz);");
+"#,
+    )
+    .expand_tt("foobar!(baz);");
 
     fn get_id(t: &tt::TokenTree) -> Option<u32> {
         if let tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) = t {
@@ -77,18 +80,47 @@ macro_rules! foobar {
     }
 
     assert_eq!(expansion.token_trees.len(), 3);
-    // ($e:ident) => { foo bar $e }
-    //   0 1            2   3   4
-    assert_eq!(get_id(&expansion.token_trees[0]), Some(2));
-    assert_eq!(get_id(&expansion.token_trees[1]), Some(3));
+    // {($e:ident) => { foo bar $e }}
+    // 012345      67 8 9   T   12
+    assert_eq!(get_id(&expansion.token_trees[0]), Some(9));
+    assert_eq!(get_id(&expansion.token_trees[1]), Some(10));
 
-    // So baz should be 5
-    assert_eq!(get_id(&expansion.token_trees[2]), Some(5));
+    // The input args of macro call include parentheses:
+    // (baz)
+    // So baz should be 12+1+1
+    assert_eq!(get_id(&expansion.token_trees[2]), Some(14));
+}
+
+#[test]
+fn test_token_map() {
+    let expanded = parse_macro(
+        r#"
+macro_rules! foobar {
+    ($e:ident) => { fn $e() {} }
+}
+"#,
+    )
+    .expand_tt("foobar!(baz);");
+
+    let (node, token_map) = token_tree_to_syntax_node(&expanded, FragmentKind::Items).unwrap();
+    let content = node.syntax_node().to_string();
+
+    let get_text = |id, kind| -> String {
+        content[token_map.range_by_token(id).unwrap().by_kind(kind).unwrap()].to_string()
+    };
+
+    assert_eq!(expanded.token_trees.len(), 4);
+    // {($e:ident) => { fn $e() {} }}
+    // 012345      67 8 9  T12  3
+
+    assert_eq!(get_text(tt::TokenId(9), IDENT), "fn");
+    assert_eq!(get_text(tt::TokenId(12), T!['(']), "(");
+    assert_eq!(get_text(tt::TokenId(13), T!['{']), "{");
 }
 
 #[test]
 fn test_convert_tt() {
-    let macro_definition = r#"
+    parse_macro(r#"
 macro_rules! impl_froms {
     ($e:ident: $($v:ident),*) => {
         $(
@@ -100,24 +132,17 @@ macro_rules! impl_froms {
         )*
     }
 }
-"#;
-
-    let macro_invocation = r#"
-impl_froms!(TokenTree: Leaf, Subtree);
-"#;
-
-    let rules = create_rules(macro_definition);
-    let expansion = expand(&rules, macro_invocation);
-    assert_eq!(
-        expansion.to_string(),
-        "impl From <Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree ::Leaf (it)}} \
-         impl From <Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree ::Subtree (it)}}"
-    )
+"#)
+        .assert_expand_tt(
+            "impl_froms!(TokenTree: Leaf, Subtree);",
+            "impl From <Leaf > for TokenTree {fn from (it : Leaf) -> TokenTree {TokenTree ::Leaf (it)}} \
+             impl From <Subtree > for TokenTree {fn from (it : Subtree) -> TokenTree {TokenTree ::Subtree (it)}}"
+        );
 }
 
 #[test]
 fn test_expr_order() {
-    let rules = create_rules(
+    let expanded = parse_macro(
         r#"
         macro_rules! foo {
             ($ i:expr) => {
@@ -125,11 +150,10 @@ fn test_expr_order() {
             }
         }
 "#,
-    );
-    let expanded = expand(&rules, "foo! { 1 + 1}");
-    let tree = token_tree_to_syntax_node(&expanded, FragmentKind::Items).unwrap().0.syntax_node();
+    )
+    .expand_items("foo! { 1 + 1}");
 
-    let dump = format!("{:#?}", tree);
+    let dump = format!("{:#?}", expanded);
     assert_eq_text!(
         dump.trim(),
         r#"MACRO_ITEMS@[0; 15)
@@ -161,7 +185,7 @@ fn test_expr_order() {
 
 #[test]
 fn test_fail_match_pattern_by_first_token() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ident) => (
@@ -175,16 +199,15 @@ fn test_fail_match_pattern_by_first_token() {
             )
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { = bar }", "fn bar () {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { + Baz }", "struct Baz ;");
+    )
+    .assert_expand_items("foo! { foo }", "mod foo {}")
+    .assert_expand_items("foo! { = bar }", "fn bar () {}")
+    .assert_expand_items("foo! { + Baz }", "struct Baz ;");
 }
 
 #[test]
 fn test_fail_match_pattern_by_last_token() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ident) => (
@@ -198,16 +221,15 @@ fn test_fail_match_pattern_by_last_token() {
             )
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { bar = }", "fn bar () {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { Baz + }", "struct Baz ;");
+    )
+    .assert_expand_items("foo! { foo }", "mod foo {}")
+    .assert_expand_items("foo! { bar = }", "fn bar () {}")
+    .assert_expand_items("foo! { Baz + }", "struct Baz ;");
 }
 
 #[test]
 fn test_fail_match_pattern_by_word_token() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ident) => (
@@ -221,16 +243,15 @@ fn test_fail_match_pattern_by_word_token() {
             )
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "mod foo {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { spam bar }", "fn bar () {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { eggs Baz }", "struct Baz ;");
+    )
+    .assert_expand_items("foo! { foo }", "mod foo {}")
+    .assert_expand_items("foo! { spam bar }", "fn bar () {}")
+    .assert_expand_items("foo! { eggs Baz }", "struct Baz ;");
 }
 
 #[test]
 fn test_match_group_pattern_by_separator_token() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:ident),*) => ($ (
@@ -245,16 +266,15 @@ fn test_match_group_pattern_by_separator_token() {
             )
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "mod foo {} mod bar {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo# bar }", "fn foo () {} fn bar () {}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { Foo,# Bar }", "struct Foo ; struct Bar ;");
+    )
+    .assert_expand_items("foo! { foo, bar }", "mod foo {} mod bar {}")
+    .assert_expand_items("foo! { foo# bar }", "fn foo () {} fn bar () {}")
+    .assert_expand_items("foo! { Foo,# Bar }", "struct Foo ; struct Bar ;");
 }
 
 #[test]
 fn test_match_group_pattern_with_multiple_defs() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:ident),*) => ( struct Bar { $ (
@@ -262,19 +282,13 @@ fn test_match_group_pattern_with_multiple_defs() {
             )*} );
         }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        "foo! { foo, bar }",
-        "struct Bar {fn foo {} fn bar {}}",
-    );
+    )
+    .assert_expand_items("foo! { foo, bar }", "struct Bar {fn foo {} fn bar {}}");
 }
 
 #[test]
 fn test_match_group_pattern_with_multiple_statement() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:ident),*) => ( fn baz { $ (
@@ -282,14 +296,13 @@ fn test_match_group_pattern_with_multiple_statement() {
             )*} );
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "fn baz {foo () ; bar () ;}");
+    )
+    .assert_expand_items("foo! { foo, bar }", "fn baz {foo () ; bar () ;}");
 }
 
 #[test]
 fn test_match_group_pattern_with_multiple_statement_without_semi() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:ident),*) => ( fn baz { $ (
@@ -297,14 +310,13 @@ fn test_match_group_pattern_with_multiple_statement_without_semi() {
             );*} );
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo, bar }", "fn baz {foo () ;bar ()}");
+    )
+    .assert_expand_items("foo! { foo, bar }", "fn baz {foo () ;bar ()}");
 }
 
 #[test]
 fn test_match_group_empty_fixed_token() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:ident)* #abc) => ( fn baz { $ (
@@ -312,69 +324,59 @@ fn test_match_group_empty_fixed_token() {
             )*} );
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! {#abc}", "fn baz {}");
+    )
+    .assert_expand_items("foo! {#abc}", "fn baz {}");
 }
 
 #[test]
 fn test_match_group_in_subtree() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             (fn $name:ident {$($i:ident)*} ) => ( fn $name() { $ (
                 $ i ();
             )*} );
         }"#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! {fn baz {a b} }", "fn baz () {a () ; b () ;}");
+    )
+    .assert_expand_items("foo! {fn baz {a b} }", "fn baz () {a () ; b () ;}");
 }
 
 #[test]
 fn test_match_group_with_multichar_sep() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             (fn $name:ident {$($i:literal)*} ) => ( fn $name() -> bool { $($i)&&*} );
         }"#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        "foo! (fn baz {true true} );",
-        "fn baz () -> bool {true &&true}",
-    );
+    )
+    .assert_expand_items("foo! (fn baz {true true} );", "fn baz () -> bool {true &&true}");
 }
 
 #[test]
 fn test_match_group_zero_match() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ( $($i:ident)* ) => ();
         }"#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! ();", "");
+    )
+    .assert_expand_items("foo! ();", "");
 }
 
 #[test]
 fn test_match_group_in_group() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             { $( ( $($i:ident)* ) )* } => ( $( ( $($i)* ) )* );
         }"#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, "foo! ( (a b) );", "(a b)");
+    )
+    .assert_expand_items("foo! ( (a b) );", "(a b)");
 }
 
 #[test]
 fn test_expand_to_item_list() {
-    let rules = create_rules(
+    let tree = parse_macro(
         "
             macro_rules! structs {
                 ($($i:ident),*) => {
@@ -382,9 +384,8 @@ fn test_expand_to_item_list() {
                 }
             }
             ",
-    );
-    let expansion = expand(&rules, "structs!(Foo, Bar);");
-    let tree = token_tree_to_syntax_node(&expansion, FragmentKind::Items).unwrap().0.syntax_node();
+    )
+    .expand_items("structs!(Foo, Bar);");
     assert_eq!(
         format!("{:#?}", tree).trim(),
         r#"
@@ -441,7 +442,7 @@ fn test_expand_literals_to_token_tree() {
         unreachable!("It is not a literal");
     }
 
-    let rules = create_rules(
+    let expansion = parse_macro(
         r#"
             macro_rules! literals {
                 ($i:ident) => {
@@ -454,8 +455,8 @@ fn test_expand_literals_to_token_tree() {
                 }
             }
             "#,
-    );
-    let expansion = expand(&rules, "literals!(foo);");
+    )
+    .expand_tt("literals!(foo);");
     let stm_tokens = &to_subtree(&expansion.token_trees[0]).token_trees;
 
     // [let] [a] [=] ['c'] [;]
@@ -470,7 +471,7 @@ fn test_expand_literals_to_token_tree() {
 
 #[test]
 fn test_two_idents() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ident, $ j:ident) => {
@@ -478,18 +479,13 @@ fn test_two_idents() {
             }
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        "foo! { foo, bar }",
-        "fn foo () {let a = foo ; let b = bar ;}",
-    );
+    )
+    .assert_expand_items("foo! { foo, bar }", "fn foo () {let a = foo ; let b = bar ;}");
 }
 
 #[test]
 fn test_tt_to_stmts() {
-    let rules = create_rules(
+    let stmts = parse_macro(
         r#"
         macro_rules! foo {
             () => {
@@ -499,11 +495,8 @@ fn test_tt_to_stmts() {
             }
         }
 "#,
-    );
-
-    let expanded = expand(&rules, "foo!{}");
-    let stmts =
-        token_tree_to_syntax_node(&expanded, FragmentKind::Statements).unwrap().0.syntax_node();
+    )
+    .expand_statements("foo!{}");
 
     assert_eq!(
         format!("{:#?}", stmts).trim(),
@@ -543,7 +536,7 @@ fn test_tt_to_stmts() {
 
 #[test]
 fn test_match_literal() {
-    let rules = create_rules(
+    parse_macro(
         r#"
     macro_rules! foo {
         ('(') => {
@@ -551,8 +544,8 @@ fn test_match_literal() {
         }
     }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! ['('];", "fn foo () {}");
+    )
+    .assert_expand_items("foo! ['('];", "fn foo () {}");
 }
 
 // The following tests are port from intellij-rust directly
@@ -560,7 +553,7 @@ fn test_match_literal() {
 
 #[test]
 fn test_path() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:path) => {
@@ -568,11 +561,9 @@ fn test_path() {
             }
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "fn foo () {let a = foo ;}");
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    )
+    .assert_expand_items("foo! { foo }", "fn foo () {let a = foo ;}")
+    .assert_expand_items(
         "foo! { bar::<u8>::baz::<u8> }",
         "fn foo () {let a = bar ::< u8 >:: baz ::< u8 > ;}",
     );
@@ -580,7 +571,7 @@ fn test_path() {
 
 #[test]
 fn test_two_paths() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:path, $ j:path) => {
@@ -588,18 +579,13 @@ fn test_two_paths() {
             }
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        "foo! { foo, bar }",
-        "fn foo () {let a = foo ; let b = bar ;}",
-    );
+    )
+    .assert_expand_items("foo! { foo, bar }", "fn foo () {let a = foo ; let b = bar ;}");
 }
 
 #[test]
 fn test_path_with_path() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:path) => {
@@ -607,13 +593,13 @@ fn test_path_with_path() {
             }
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! { foo }", "fn foo () {let a = foo :: bar ;}");
+    )
+    .assert_expand_items("foo! { foo }", "fn foo () {let a = foo :: bar ;}");
 }
 
 #[test]
 fn test_expr() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:expr) => {
@@ -621,11 +607,8 @@ fn test_expr() {
             }
         }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    )
+    .assert_expand_items(
         "foo! { 2 + 2 * baz(3).quux() }",
         "fn bar () {2 + 2 * baz (3) . quux () ;}",
     );
@@ -633,7 +616,7 @@ fn test_expr() {
 
 #[test]
 fn test_last_expr() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! vec {
             ($($item:expr),*) => {
@@ -647,10 +630,8 @@ fn test_last_expr() {
             };
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    )
+    .assert_expand_items(
         "vec!(1,2,3);",
         "{let mut v = Vec :: new () ; v . push (1) ; v . push (2) ; v . push (3) ; v}",
     );
@@ -658,7 +639,7 @@ fn test_last_expr() {
 
 #[test]
 fn test_ty() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ty) => (
@@ -666,18 +647,13 @@ fn test_ty() {
             )
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        "foo! { Baz<u8> }",
-        "fn bar () -> Baz < u8 > {unimplemented ! ()}",
-    );
+    )
+    .assert_expand_items("foo! { Baz<u8> }", "fn bar () -> Baz < u8 > {unimplemented ! ()}");
 }
 
 #[test]
 fn test_ty_with_complex_type() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:ty) => (
@@ -685,20 +661,14 @@ fn test_ty_with_complex_type() {
             )
         }
 "#,
-    );
-
+    )
     // Reference lifetime struct with generic type
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    .assert_expand_items(
         "foo! { &'a Baz<u8> }",
         "fn bar () -> & 'a Baz < u8 > {unimplemented ! ()}",
-    );
-
+    )
     // extern "Rust" func type
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    .assert_expand_items(
         r#"foo! { extern "Rust" fn() -> Ret }"#,
         r#"fn bar () -> extern "Rust" fn () -> Ret {unimplemented ! ()}"#,
     );
@@ -706,19 +676,19 @@ fn test_ty_with_complex_type() {
 
 #[test]
 fn test_pat_() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:pat) => { fn foo() { let $ i; } }
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! { (a, b) }", "fn foo () {let (a , b) ;}");
+    )
+    .assert_expand_items("foo! { (a, b) }", "fn foo () {let (a , b) ;}");
 }
 
 #[test]
 fn test_stmt() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:stmt) => (
@@ -726,14 +696,14 @@ fn test_stmt() {
             )
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! { 2 }", "fn bar () {2 ;}");
-    assert_expansion(MacroKind::Items, &rules, "foo! { let a = 0 }", "fn bar () {let a = 0 ;}");
+    )
+    .assert_expand_items("foo! { 2 }", "fn bar () {2 ;}")
+    .assert_expand_items("foo! { let a = 0 }", "fn bar () {let a = 0 ;}");
 }
 
 #[test]
 fn test_single_item() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:item) => (
@@ -741,13 +711,13 @@ fn test_single_item() {
             )
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, "foo! {mod c {}}", "mod c {}");
+    )
+    .assert_expand_items("foo! {mod c {}}", "mod c {}");
 }
 
 #[test]
 fn test_all_items() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ ($ i:item)*) => ($ (
@@ -755,10 +725,8 @@ fn test_all_items() {
             )*)
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).
+    assert_expand_items(
         r#"
         foo! {
             extern crate a;
@@ -782,19 +750,19 @@ fn test_all_items() {
 
 #[test]
 fn test_block() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:block) => { fn foo() $ i }
         }
 "#,
-    );
-    assert_expansion(MacroKind::Stmts, &rules, "foo! { { 1; } }", "fn foo () {1 ;}");
+    )
+    .assert_expand_statements("foo! { { 1; } }", "fn foo () {1 ;}");
 }
 
 #[test]
 fn test_meta() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($ i:meta) => (
@@ -803,10 +771,8 @@ fn test_meta() {
             )
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    )
+    .assert_expand_items(
         r#"foo! { cfg(target_os = "windows") }"#,
         r#"# [cfg (target_os = "windows")] fn bar () {}"#,
     );
@@ -814,7 +780,7 @@ fn test_meta() {
 
 #[test]
 fn test_meta_doc_comments() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
             ($(#[$ i:meta])+) => (
@@ -823,10 +789,8 @@ fn test_meta_doc_comments() {
             )
         }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).
+    assert_expand_items(
         r#"foo! {
             /// Single Line Doc 1
             /**
@@ -839,69 +803,68 @@ fn test_meta_doc_comments() {
 
 #[test]
 fn test_tt_block() {
-    let rules = create_rules(
+    parse_macro(
         r#"
             macro_rules! foo {
                 ($ i:tt) => { fn foo() $ i }
             }
     "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, r#"foo! { { 1; } }"#, r#"fn foo () {1 ;}"#);
+    )
+    .assert_expand_items(r#"foo! { { 1; } }"#, r#"fn foo () {1 ;}"#);
 }
 
 #[test]
 fn test_tt_group() {
-    let rules = create_rules(
+    parse_macro(
         r#"
             macro_rules! foo {
                  ($($ i:tt)*) => { $($ i)* }
             }
     "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, r#"foo! { fn foo() {} }"#, r#"fn foo () {}"#);
+    )
+    .assert_expand_items(r#"foo! { fn foo() {} }"#, r#"fn foo () {}"#);
 }
 #[test]
 fn test_lifetime() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
               ($ lt:lifetime) => { struct Ref<$ lt>{ s: &$ lt str } }
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, r#"foo!{'a}"#, r#"struct Ref <'a > {s : &'a str}"#);
+    )
+    .assert_expand_items(r#"foo!{'a}"#, r#"struct Ref <'a > {s : &'a str}"#);
 }
 
 #[test]
 fn test_literal() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
               ($ type:ty $ lit:literal) => { const VALUE: $ type = $ lit;};
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, r#"foo!(u8 0);"#, r#"const VALUE : u8 = 0 ;"#);
+    )
+    .assert_expand_items(r#"foo!(u8 0);"#, r#"const VALUE : u8 = 0 ;"#);
 }
 
 #[test]
 fn test_vis() {
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! foo {
               ($ vis:vis $ name:ident) => { $ vis fn $ name() {}};
         }
 "#,
-    );
-    assert_expansion(MacroKind::Items, &rules, r#"foo!(pub foo);"#, r#"pub fn foo () {}"#);
-
-    // test optional casse
-    assert_expansion(MacroKind::Items, &rules, r#"foo!(foo);"#, r#"fn foo () {}"#);
+    )
+    .assert_expand_items(r#"foo!(pub foo);"#, r#"pub fn foo () {}"#)
+    // test optional cases
+    .assert_expand_items(r#"foo!(foo);"#, r#"fn foo () {}"#);
 }
 
 #[test]
 fn test_inner_macro_rules() {
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! foo {
     ($a:ident, $b:ident, $c:tt) => {
@@ -917,10 +880,8 @@ macro_rules! foo {
     }
 }
 "#,
-    );
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).
+    assert_expand_items(
         r#"foo!(x,y, 1);"#,
         r#"macro_rules ! bar {($ bi : ident) => {fn $ bi () -> u8 {1}}} bar ! (x) ; fn y () -> u8 {1}"#,
     );
@@ -929,7 +890,7 @@ macro_rules! foo {
 // The following tests are based on real world situations
 #[test]
 fn test_vec() {
-    let rules = create_rules(
+    let fixture = parse_macro(
         r#"
          macro_rules! vec {
             ($($item:expr),*) => {
@@ -944,16 +905,14 @@ fn test_vec() {
 }
 "#,
     );
-    assert_expansion(MacroKind::Items, &rules, r#"vec!();"#, r#"{let mut v = Vec :: new () ; v}"#);
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
-        r#"vec![1u32,2];"#,
-        r#"{let mut v = Vec :: new () ; v . push (1u32) ; v . push (2) ; v}"#,
-    );
+    fixture
+        .assert_expand_items(r#"vec!();"#, r#"{let mut v = Vec :: new () ; v}"#)
+        .assert_expand_items(
+            r#"vec![1u32,2];"#,
+            r#"{let mut v = Vec :: new () ; v . push (1u32) ; v . push (2) ; v}"#,
+        );
 
-    let expansion = expand(&rules, r#"vec![1u32,2];"#);
-    let tree = token_tree_to_syntax_node(&expansion, FragmentKind::Expr).unwrap().0.syntax_node();
+    let tree = fixture.expand_expr(r#"vec![1u32,2];"#);
 
     assert_eq!(
         format!("{:#?}", tree).trim(),
@@ -1027,7 +986,7 @@ fn test_vec() {
 fn test_winapi_struct() {
     // from https://github.com/retep998/winapi-rs/blob/a7ef2bca086aae76cf6c4ce4c2552988ed9798ad/src/macros.rs#L366
 
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! STRUCT {
     ($(#[$attrs:meta])* struct $name:ident {
@@ -1049,17 +1008,19 @@ macro_rules! STRUCT {
     );
 }
 "#,
-    );
+    ).
     // from https://github.com/retep998/winapi-rs/blob/a7ef2bca086aae76cf6c4ce4c2552988ed9798ad/src/shared/d3d9caps.rs
-    assert_expansion(MacroKind::Items, &rules, r#"STRUCT!{struct D3DVSHADERCAPS2_0 {Caps: u8,}}"#,
-        "# [repr (C)] # [derive (Copy)] pub struct D3DVSHADERCAPS2_0 {pub Caps : u8 ,} impl Clone for D3DVSHADERCAPS2_0 {# [inline] fn clone (& self) -> D3DVSHADERCAPS2_0 {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DVSHADERCAPS2_0 {# [inline] fn default () -> D3DVSHADERCAPS2_0 {unsafe {$crate :: _core :: mem :: zeroed ()}}}");
-    assert_expansion(MacroKind::Items, &rules, r#"STRUCT!{#[cfg_attr(target_arch = "x86", repr(packed))] struct D3DCONTENTPROTECTIONCAPS {Caps : u8 ,}}"#,
-        "# [repr (C)] # [derive (Copy)] # [cfg_attr (target_arch = \"x86\" , repr (packed))] pub struct D3DCONTENTPROTECTIONCAPS {pub Caps : u8 ,} impl Clone for D3DCONTENTPROTECTIONCAPS {# [inline] fn clone (& self) -> D3DCONTENTPROTECTIONCAPS {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DCONTENTPROTECTIONCAPS {# [inline] fn default () -> D3DCONTENTPROTECTIONCAPS {unsafe {$crate :: _core :: mem :: zeroed ()}}}");
+    assert_expand_items(r#"STRUCT!{struct D3DVSHADERCAPS2_0 {Caps: u8,}}"#,
+        "# [repr (C)] # [derive (Copy)] pub struct D3DVSHADERCAPS2_0 {pub Caps : u8 ,} impl Clone for D3DVSHADERCAPS2_0 {# [inline] fn clone (& self) -> D3DVSHADERCAPS2_0 {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DVSHADERCAPS2_0 {# [inline] fn default () -> D3DVSHADERCAPS2_0 {unsafe {$crate :: _core :: mem :: zeroed ()}}}"
+    )
+    .assert_expand_items(r#"STRUCT!{#[cfg_attr(target_arch = "x86", repr(packed))] struct D3DCONTENTPROTECTIONCAPS {Caps : u8 ,}}"#,
+        "# [repr (C)] # [derive (Copy)] # [cfg_attr (target_arch = \"x86\" , repr (packed))] pub struct D3DCONTENTPROTECTIONCAPS {pub Caps : u8 ,} impl Clone for D3DCONTENTPROTECTIONCAPS {# [inline] fn clone (& self) -> D3DCONTENTPROTECTIONCAPS {* self}} # [cfg (feature = \"impl-default\")] impl Default for D3DCONTENTPROTECTIONCAPS {# [inline] fn default () -> D3DCONTENTPROTECTIONCAPS {unsafe {$crate :: _core :: mem :: zeroed ()}}}"
+    );
 }
 
 #[test]
 fn test_int_base() {
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! int_base {
     ($Trait:ident for $T:ident as $U:ident -> $Radix:ident) => {
@@ -1072,17 +1033,15 @@ macro_rules! int_base {
     }
 }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, r#" int_base!{Binary for isize as usize -> Binary}"#,
+    ).assert_expand_items(r#" int_base!{Binary for isize as usize -> Binary}"#,
         "# [stable (feature = \"rust1\" , since = \"1.0.0\")] impl fmt ::Binary for isize {fn fmt (& self , f : & mut fmt :: Formatter < \'_ >) -> fmt :: Result {Binary . fmt_int (* self as usize , f)}}"
-        );
+    );
 }
 
 #[test]
 fn test_generate_pattern_iterators() {
     // from https://github.com/rust-lang/rust/blob/316a391dcb7d66dc25f1f9a4ec9d368ef7615005/src/libcore/str/mod.rs
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! generate_pattern_iterators {
         { double ended; with $(#[$common_stability_attribute:meta])*,
@@ -1093,11 +1052,7 @@ macro_rules! generate_pattern_iterators {
         }
 }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).assert_expand_items(
         r#"generate_pattern_iterators ! ( double ended ; with # [ stable ( feature = "rust1" , since = "1.0.0" ) ] , Split , RSplit , & 'a str );"#,
         "fn foo () {}",
     );
@@ -1106,7 +1061,7 @@ macro_rules! generate_pattern_iterators {
 #[test]
 fn test_impl_fn_for_zst() {
     // from https://github.com/rust-lang/rust/blob/5d20ff4d2718c820632b38c1e49d4de648a9810b/src/libcore/internal_macros.rs
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! impl_fn_for_zst  {
         {  $( $( #[$attr: meta] )*
@@ -1147,9 +1102,7 @@ $body: block; )+
 }
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, r#"
+    ).assert_expand_items(r#"
 impl_fn_for_zst !   {
      # [ derive ( Clone ) ]
      struct   CharEscapeDebugContinue   impl   Fn   =   | c :   char |   ->   char :: EscapeDebug   {
@@ -1166,13 +1119,14 @@ impl_fn_for_zst !   {
      } ;
  }
 "#,
-        "# [derive (Clone)] struct CharEscapeDebugContinue ; impl Fn < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDebug {{c . escape_debug_ext (false)}}} impl FnMut < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDebugContinue {type Output = char :: EscapeDebug ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeUnicode ; impl Fn < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeUnicode {{c . escape_unicode ()}}} impl FnMut < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeUnicode {type Output = char :: EscapeUnicode ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeDefault ; impl Fn < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDefault {{c . escape_default ()}}} impl FnMut < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDefault {type Output = char :: EscapeDefault ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (& self , (c ,))}}");
+        "# [derive (Clone)] struct CharEscapeDebugContinue ; impl Fn < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDebug {{c . escape_debug_ext (false)}}} impl FnMut < (char ,) > for CharEscapeDebugContinue {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDebugContinue {type Output = char :: EscapeDebug ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDebug {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeUnicode ; impl Fn < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeUnicode {{c . escape_unicode ()}}} impl FnMut < (char ,) > for CharEscapeUnicode {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeUnicode {type Output = char :: EscapeUnicode ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeUnicode {Fn :: call (& self , (c ,))}} # [derive (Clone)] struct CharEscapeDefault ; impl Fn < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call (& self , (c ,) : (char ,)) -> char :: EscapeDefault {{c . escape_default ()}}} impl FnMut < (char ,) > for CharEscapeDefault {# [inline] extern \"rust-call\" fn call_mut (& mut self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (&* self , (c ,))}} impl FnOnce < (char ,) > for CharEscapeDefault {type Output = char :: EscapeDefault ; # [inline] extern \"rust-call\" fn call_once (self , (c ,) : (char ,)) -> char :: EscapeDefault {Fn :: call (& self , (c ,))}}"
+    );
 }
 
 #[test]
 fn test_impl_nonzero_fmt() {
     // from https://github.com/rust-lang/rust/blob/316a391dcb7d66dc25f1f9a4ec9d368ef7615005/src/libcore/num/mod.rs#L12
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! impl_nonzero_fmt {
             ( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
@@ -1180,11 +1134,7 @@ fn test_impl_nonzero_fmt() {
             }
         }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).assert_expand_items(
         r#"impl_nonzero_fmt! { # [stable(feature= "nonzero",since="1.28.0")] (Debug,Display,Binary,Octal,LowerHex,UpperHex) for NonZeroU8}"#,
         "fn foo () {}",
     );
@@ -1193,7 +1143,7 @@ fn test_impl_nonzero_fmt() {
 #[test]
 fn test_cfg_if_items() {
     // from https://github.com/rust-lang/rust/blob/33fe1131cadba69d317156847be9a402b89f11bb/src/libstd/macros.rs#L986
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! __cfg_if_items {
             (($($not:meta,)*) ; ) => {};
@@ -1202,11 +1152,7 @@ fn test_cfg_if_items() {
             }
         }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).assert_expand_items(
         r#"__cfg_if_items ! { ( rustdoc , ) ; ( ( ) ( # [ cfg ( any ( target_os = "redox" , unix ) ) ] # [ stable ( feature = "rust1" , since = "1.0.0" ) ] pub use sys :: ext as unix ; # [ cfg ( windows ) ] # [ stable ( feature = "rust1" , since = "1.0.0" ) ] pub use sys :: ext as windows ; # [ cfg ( any ( target_os = "linux" , target_os = "l4re" ) ) ] pub mod linux ; ) ) , }"#,
         "__cfg_if_items ! {(rustdoc ,) ;}",
     );
@@ -1215,7 +1161,7 @@ fn test_cfg_if_items() {
 #[test]
 fn test_cfg_if_main() {
     // from https://github.com/rust-lang/rust/blob/3d211248393686e0f73851fc7548f6605220fbe1/src/libpanic_unwind/macros.rs#L9
-    let rules = create_rules(
+    parse_macro(
         r#"
         macro_rules! cfg_if {
             ($(
@@ -1236,9 +1182,7 @@ fn test_cfg_if_main() {
             };
         }
 "#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, r#"
+    ).assert_expand_items(r#"
 cfg_if !   {
      if   # [ cfg ( target_env   =   "msvc" ) ]   {
          // no extra unwinder support needed
@@ -1250,11 +1194,8 @@ cfg_if !   {
      }
  }
 "#,
-        "__cfg_if_items ! {() ; ((target_env = \"msvc\") ()) , ((all (target_arch = \"wasm32\" , not (target_os = \"emscripten\"))) ()) , (() (mod libunwind ; pub use libunwind :: * ;)) ,}");
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+        "__cfg_if_items ! {() ; ((target_env = \"msvc\") ()) , ((all (target_arch = \"wasm32\" , not (target_os = \"emscripten\"))) ()) , (() (mod libunwind ; pub use libunwind :: * ;)) ,}"
+    ).assert_expand_items(
         r#"
 cfg_if ! { @ __apply cfg ( all ( not ( any ( not ( any ( target_os = "solaris" , target_os = "illumos" ) ) ) ) ) ) , }
 "#,
@@ -1265,7 +1206,7 @@ cfg_if ! { @ __apply cfg ( all ( not ( any ( not ( any ( target_os = "solaris" ,
 #[test]
 fn test_proptest_arbitrary() {
     // from https://github.com/AltSysrq/proptest/blob/d1c4b049337d2f75dd6f49a095115f7c532e5129/proptest/src/arbitrary/macros.rs#L16
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! arbitrary {
     ([$($bounds : tt)*] $typ: ty, $strat: ty, $params: ty;
@@ -1280,22 +1221,21 @@ macro_rules! arbitrary {
     };
 
 }"#,
-    );
-
-    assert_expansion(MacroKind::Items, &rules, r#"arbitrary !   ( [ A : Arbitrary ]
+    ).assert_expand_items(r#"arbitrary !   ( [ A : Arbitrary ]
         Vec < A > ,
         VecStrategy < A :: Strategy > ,
         RangedParams1 < A :: Parameters > ;
         args =>   { let product_unpack !   [ range , a ] = args ; vec ( any_with :: < A >   ( a ) , range ) }
     ) ;"#,
-    "impl <A : Arbitrary > $crate :: arbitrary :: Arbitrary for Vec < A > {type Parameters = RangedParams1 < A :: Parameters > ; type Strategy = VecStrategy < A :: Strategy > ; fn arbitrary_with (args : Self :: Parameters) -> Self :: Strategy {{let product_unpack ! [range , a] = args ; vec (any_with :: < A > (a) , range)}}}");
+    "impl <A : Arbitrary > $crate :: arbitrary :: Arbitrary for Vec < A > {type Parameters = RangedParams1 < A :: Parameters > ; type Strategy = VecStrategy < A :: Strategy > ; fn arbitrary_with (args : Self :: Parameters) -> Self :: Strategy {{let product_unpack ! [range , a] = args ; vec (any_with :: < A > (a) , range)}}}"
+    );
 }
 
 #[test]
 fn test_old_ridl() {
     // This is from winapi 2.8, which do not have a link from github
     //
-    let rules = create_rules(
+    let expanded = parse_macro(
         r#"
 #[macro_export]
 macro_rules! RIDL {
@@ -1311,21 +1251,17 @@ macro_rules! RIDL {
         }
     };
 }"#,
-    );
+    ).expand_tt(r#"
+    RIDL!{interface ID3D11Asynchronous(ID3D11AsynchronousVtbl): ID3D11DeviceChild(ID3D11DeviceChildVtbl) {
+        fn GetDataSize(&mut self) -> UINT
+    }}"#);
 
-    let expanded = expand(
-        &rules,
-        r#"
-RIDL!{interface ID3D11Asynchronous(ID3D11AsynchronousVtbl): ID3D11DeviceChild(ID3D11DeviceChildVtbl) {
-    fn GetDataSize(&mut self) -> UINT
-}}"#,
-    );
     assert_eq!(expanded.to_string(), "impl ID3D11Asynchronous {pub unsafe fn GetDataSize (& mut self) -> UINT {((* self . lpVtbl) .GetDataSize) (self)}}");
 }
 
 #[test]
 fn test_quick_error() {
-    let rules = create_rules(
+    let expanded = parse_macro(
         r#"
 macro_rules! quick_error {
 
@@ -1348,10 +1284,8 @@ macro_rules! quick_error {
 
 }
 "#,
-    );
-
-    let expanded = expand(
-        &rules,
+    )
+    .expand_tt(
         r#"
 quick_error ! (SORT [enum Wrapped # [derive (Debug)]] items [
         => One : UNIT [] {}
@@ -1365,7 +1299,7 @@ quick_error ! (SORT [enum Wrapped # [derive (Debug)]] items [
 
 #[test]
 fn test_empty_repeat_vars_in_empty_repeat_vars() {
-    let rules = create_rules(
+    parse_macro(
         r#"
 macro_rules! delegate_impl {
     ([$self_type:ident, $self_wrap:ty, $self_map:ident]
@@ -1412,103 +1346,117 @@ macro_rules! delegate_impl {
     }
 }
 "#,
-    );
-
-    assert_expansion(
-        MacroKind::Items,
-        &rules,
+    ).assert_expand_items(
         r#"delegate_impl ! {[G , & 'a mut G , deref] pub trait Data : GraphBase {@ section type type NodeWeight ;}}"#,
         "impl <> Data for & \'a mut G where G : Data {}",
     );
 }
 
-pub(crate) fn create_rules(macro_definition: &str) -> MacroRules {
-    let source_file = ast::SourceFile::parse(macro_definition).ok().unwrap();
-    let macro_definition =
-        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+#[test]
+fn expr_interpolation() {
+    let expanded = parse_macro(
+        r#"
+        macro_rules! id {
+            ($expr:expr) => {
+                map($expr)
+            }
+        }
+        "#,
+    )
+    .expand_expr("id!(x + foo);");
 
-    let (definition_tt, _) = ast_to_token_tree(&macro_definition.token_tree().unwrap()).unwrap();
-    crate::MacroRules::parse(&definition_tt).unwrap()
+    assert_eq!(expanded.to_string(), "map(x+foo)");
 }
 
-pub(crate) fn expand(rules: &MacroRules, invocation: &str) -> tt::Subtree {
-    let source_file = ast::SourceFile::parse(invocation).ok().unwrap();
-    let macro_invocation =
-        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+pub(crate) struct MacroFixture {
+    rules: MacroRules,
+}
 
-    let (invocation_tt, _) = ast_to_token_tree(&macro_invocation.token_tree().unwrap()).unwrap();
+impl MacroFixture {
+    pub(crate) fn expand_tt(&self, invocation: &str) -> tt::Subtree {
+        let source_file = ast::SourceFile::parse(invocation).ok().unwrap();
+        let macro_invocation =
+            source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
 
-    rules.expand(&invocation_tt).unwrap()
-}
+        let (invocation_tt, _) =
+            ast_to_token_tree(&macro_invocation.token_tree().unwrap()).unwrap();
 
-pub(crate) enum MacroKind {
-    Items,
-    Stmts,
-}
+        self.rules.expand(&invocation_tt).unwrap()
+    }
 
-pub(crate) fn assert_expansion(
-    kind: MacroKind,
-    rules: &MacroRules,
-    invocation: &str,
-    expected: &str,
-) -> tt::Subtree {
-    let expanded = expand(rules, invocation);
-    assert_eq!(expanded.to_string(), expected);
+    fn expand_items(&self, invocation: &str) -> SyntaxNode {
+        let expanded = self.expand_tt(invocation);
+        token_tree_to_syntax_node(&expanded, FragmentKind::Items).unwrap().0.syntax_node()
+    }
 
-    let expected = expected.replace("$crate", "C_C__C");
+    fn expand_statements(&self, invocation: &str) -> SyntaxNode {
+        let expanded = self.expand_tt(invocation);
+        token_tree_to_syntax_node(&expanded, FragmentKind::Statements).unwrap().0.syntax_node()
+    }
 
-    // wrap the given text to a macro call
-    let expected = {
-        let wrapped = format!("wrap_macro!( {} )", expected);
-        let wrapped = ast::SourceFile::parse(&wrapped);
-        let wrapped = wrapped.tree().syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
-        let mut wrapped = ast_to_token_tree(&wrapped).unwrap().0;
-        wrapped.delimiter = tt::Delimiter::None;
-        wrapped
-    };
-    let (expanded_tree, expected_tree) = match kind {
-        MacroKind::Items => {
-            let expanded_tree =
-                token_tree_to_syntax_node(&expanded, FragmentKind::Items).unwrap().0.syntax_node();
-            let expected_tree =
-                token_tree_to_syntax_node(&expected, FragmentKind::Items).unwrap().0.syntax_node();
-
-            (
-                debug_dump_ignore_spaces(&expanded_tree).trim().to_string(),
-                debug_dump_ignore_spaces(&expected_tree).trim().to_string(),
-            )
-        }
+    fn expand_expr(&self, invocation: &str) -> SyntaxNode {
+        let expanded = self.expand_tt(invocation);
+        token_tree_to_syntax_node(&expanded, FragmentKind::Expr).unwrap().0.syntax_node()
+    }
 
-        MacroKind::Stmts => {
-            let expanded_tree = token_tree_to_syntax_node(&expanded, FragmentKind::Statements)
-                .unwrap()
-                .0
-                .syntax_node();
-            let expected_tree = token_tree_to_syntax_node(&expected, FragmentKind::Statements)
-                .unwrap()
-                .0
-                .syntax_node();
-
-            (
-                debug_dump_ignore_spaces(&expanded_tree).trim().to_string(),
-                debug_dump_ignore_spaces(&expected_tree).trim().to_string(),
-            )
-        }
-    };
+    fn assert_expand_tt(&self, invocation: &str, expected: &str) {
+        let expansion = self.expand_tt(invocation);
+        assert_eq!(expansion.to_string(), expected);
+    }
 
-    let expected_tree = expected_tree.replace("C_C__C", "$crate");
-    assert_eq!(
-        expanded_tree, expected_tree,
-        "\nleft:\n{}\nright:\n{}",
-        expanded_tree, expected_tree,
-    );
+    fn assert_expand_items(&self, invocation: &str, expected: &str) -> &MacroFixture {
+        self.assert_expansion(FragmentKind::Items, invocation, expected);
+        self
+    }
+
+    fn assert_expand_statements(&self, invocation: &str, expected: &str) -> &MacroFixture {
+        self.assert_expansion(FragmentKind::Statements, invocation, expected);
+        self
+    }
 
-    expanded
+    fn assert_expansion(&self, kind: FragmentKind, invocation: &str, expected: &str) {
+        let expanded = self.expand_tt(invocation);
+        assert_eq!(expanded.to_string(), expected);
+
+        let expected = expected.replace("$crate", "C_C__C");
+
+        // wrap the given text to a macro call
+        let expected = {
+            let wrapped = format!("wrap_macro!( {} )", expected);
+            let wrapped = ast::SourceFile::parse(&wrapped);
+            let wrapped =
+                wrapped.tree().syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+            let mut wrapped = ast_to_token_tree(&wrapped).unwrap().0;
+            wrapped.delimiter = None;
+            wrapped
+        };
+
+        let expanded_tree = token_tree_to_syntax_node(&expanded, kind).unwrap().0.syntax_node();
+        let expanded_tree = debug_dump_ignore_spaces(&expanded_tree).trim().to_string();
+
+        let expected_tree = token_tree_to_syntax_node(&expected, kind).unwrap().0.syntax_node();
+        let expected_tree = debug_dump_ignore_spaces(&expected_tree).trim().to_string();
+
+        let expected_tree = expected_tree.replace("C_C__C", "$crate");
+        assert_eq!(
+            expanded_tree, expected_tree,
+            "\nleft:\n{}\nright:\n{}",
+            expanded_tree, expected_tree,
+        );
+    }
 }
 
-pub fn debug_dump_ignore_spaces(node: &ra_syntax::SyntaxNode) -> String {
-    use std::fmt::Write;
+pub(crate) fn parse_macro(macro_definition: &str) -> MacroFixture {
+    let source_file = ast::SourceFile::parse(macro_definition).ok().unwrap();
+    let macro_definition =
+        source_file.syntax().descendants().find_map(ast::MacroCall::cast).unwrap();
+
+    let (definition_tt, _) = ast_to_token_tree(&macro_definition.token_tree().unwrap()).unwrap();
+    let rules = MacroRules::parse(&definition_tt).unwrap();
+    MacroFixture { rules }
+}
 
+fn debug_dump_ignore_spaces(node: &ra_syntax::SyntaxNode) -> String {
     let mut level = 0;
     let mut buf = String::new();
     macro_rules! indent {
diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index 6e9e212b7..22f64a9f4 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -264,7 +264,7 @@ fn name_r(p: &mut Parser, recovery: TokenSet) {
 }
 
 fn name(p: &mut Parser) {
-    name_r(p, TokenSet::empty())
+    name_r(p, TokenSet::EMPTY)
 }
 
 fn name_ref(p: &mut Parser) {
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index f06191963..4ac1d6334 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -43,6 +43,7 @@ pub(super) const ATOM_EXPR_FIRST: TokenSet =
         T!['('],
         T!['{'],
         T!['['],
+        L_DOLLAR,
         T![|],
         T![move],
         T![box],
@@ -248,7 +249,12 @@ fn lambda_expr(p: &mut Parser) -> CompletedMarker {
             p.error("expected `{`");
         }
     }
-    expr(p);
+
+    if p.at_ts(EXPR_FIRST) {
+        expr(p);
+    } else {
+        p.error("expected expression");
+    }
     m.complete(p, LAMBDA_EXPR)
 }
 
@@ -438,7 +444,7 @@ fn match_arm(p: &mut Parser) -> BlockLike {
     // }
     attributes::outer_attributes(p);
 
-    patterns::pattern_list_r(p, TokenSet::empty());
+    patterns::pattern_list_r(p, TokenSet::EMPTY);
     if p.at(T![if]) {
         match_guard(p);
     }
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 370990e21..6e23d9b72 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -33,7 +33,7 @@ pub(super) enum ItemFlavor {
 
 pub(super) const ITEM_RECOVERY_SET: TokenSet = token_set![
     FN_KW, STRUCT_KW, ENUM_KW, IMPL_KW, TRAIT_KW, CONST_KW, STATIC_KW, LET_KW, MOD_KW, PUB_KW,
-    CRATE_KW, USE_KW
+    CRATE_KW, USE_KW, MACRO_KW
 ];
 
 pub(super) fn item_or_macro(p: &mut Parser, stop_on_r_curly: bool, flavor: ItemFlavor) {
@@ -249,6 +249,11 @@ fn items_without_modifiers(p: &mut Parser, m: Marker) -> Result<(), Marker> {
             // }
             adt::struct_def(p, m);
         }
+        // test pub_macro_def
+        // pub macro m($:ident) {}
+        T![macro] => {
+            macro_def(p, m);
+        }
         IDENT if p.at_contextual_kw("union") && p.nth(1) == IDENT => {
             // test union_items
             // union Foo {}
@@ -379,6 +384,29 @@ pub(crate) fn mod_item_list(p: &mut Parser) {
     m.complete(p, ITEM_LIST);
 }
 
+// test macro_def
+// macro m { ($i:ident) => {} }
+// macro m($i:ident) {}
+fn macro_def(p: &mut Parser, m: Marker) {
+    p.expect(T![macro]);
+    name_r(p, ITEM_RECOVERY_SET);
+    if p.at(T!['{']) {
+        token_tree(p);
+    } else if !p.at(T!['(']) {
+        p.error("unmatched `(`");
+    } else {
+        let m = p.start();
+        token_tree(p);
+        match p.current() {
+            T!['{'] | T!['['] | T!['('] => token_tree(p),
+            _ => p.error("expected `{`, `[`, `(`"),
+        }
+        m.complete(p, TOKEN_TREE);
+    }
+
+    m.complete(p, MACRO_DEF);
+}
+
 fn macro_call(p: &mut Parser) -> BlockLike {
     assert!(paths::is_use_path_start(p));
     paths::use_path(p);
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index f5d12278c..422a4e3dc 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -50,7 +50,7 @@ pub(super) fn pattern_r(p: &mut Parser, recovery_set: TokenSet) {
         //     let m!(x) = 0;
         // }
         if lhs.kind() == PATH_PAT && p.at(T![!]) {
-            let m = lhs.precede(p);
+            let m = lhs.undo_completion(p);
             items::macro_call_after_excl(p);
             m.complete(p, MACRO_CALL);
         }
diff --git a/crates/ra_parser/src/grammar/type_params.rs b/crates/ra_parser/src/grammar/type_params.rs
index 34406b5bd..50e4900c3 100644
--- a/crates/ra_parser/src/grammar/type_params.rs
+++ b/crates/ra_parser/src/grammar/type_params.rs
@@ -25,6 +25,7 @@ fn type_param_list(p: &mut Parser) {
         match p.current() {
             LIFETIME => lifetime_param(p, m),
             IDENT => type_param(p, m),
+            CONST_KW => type_const_param(p, m),
             _ => {
                 m.abandon(p);
                 p.err_and_bump("expected type parameter")
@@ -62,6 +63,16 @@ fn type_param(p: &mut Parser, m: Marker) {
     m.complete(p, TYPE_PARAM);
 }
 
+// test const_param
+// struct S<const N: u32>;
+fn type_const_param(p: &mut Parser, m: Marker) {
+    assert!(p.at(CONST_KW));
+    p.bump(T![const]);
+    name(p);
+    types::ascription(p);
+    m.complete(p, CONST_PARAM);
+}
+
 // test type_param_bounds
 // struct S<T: 'a + ?Sized + (Copy)>;
 pub(super) fn bounds(p: &mut Parser) {
diff --git a/crates/ra_parser/src/lib.rs b/crates/ra_parser/src/lib.rs
index 45241e566..65134277e 100644
--- a/crates/ra_parser/src/lib.rs
+++ b/crates/ra_parser/src/lib.rs
@@ -83,6 +83,7 @@ pub fn parse(token_source: &mut dyn TokenSource, tree_sink: &mut dyn TreeSink) {
     parse_from_tokens(token_source, tree_sink, grammar::root);
 }
 
+#[derive(Clone, Copy)]
 pub enum FragmentKind {
     Path,
     Expr,
diff --git a/crates/ra_parser/src/parser.rs b/crates/ra_parser/src/parser.rs
index dafd5247b..1071c46dc 100644
--- a/crates/ra_parser/src/parser.rs
+++ b/crates/ra_parser/src/parser.rs
@@ -208,7 +208,7 @@ impl<'t> Parser<'t> {
 
     /// Create an error node and consume the next token.
     pub(crate) fn err_and_bump(&mut self, message: &str) {
-        self.err_recover(message, TokenSet::empty());
+        self.err_recover(message, TokenSet::EMPTY);
     }
 
     /// Create an error node and consume the next token.
diff --git a/crates/ra_parser/src/syntax_kind/generated.rs b/crates/ra_parser/src/syntax_kind/generated.rs
index fe0fcdb33..af2945f57 100644
--- a/crates/ra_parser/src/syntax_kind/generated.rs
+++ b/crates/ra_parser/src/syntax_kind/generated.rs
@@ -100,6 +100,7 @@ pub enum SyntaxKind {
     TRY_KW,
     BOX_KW,
     AWAIT_KW,
+    MACRO_KW,
     AUTO_KW,
     DEFAULT_KW,
     EXISTENTIAL_KW,
@@ -136,6 +137,7 @@ pub enum SyntaxKind {
     TYPE_ALIAS_DEF,
     MACRO_CALL,
     TOKEN_TREE,
+    MACRO_DEF,
     PAREN_TYPE,
     TUPLE_TYPE,
     NEVER_TYPE,
@@ -227,6 +229,7 @@ pub enum SyntaxKind {
     TYPE_PARAM_LIST,
     LIFETIME_PARAM,
     TYPE_PARAM,
+    CONST_PARAM,
     TYPE_ARG_LIST,
     LIFETIME_ARG,
     TYPE_ARG,
@@ -251,7 +254,7 @@ impl SyntaxKind {
             | SUPER_KW | IN_KW | WHERE_KW | FOR_KW | LOOP_KW | WHILE_KW | CONTINUE_KW
             | BREAK_KW | IF_KW | ELSE_KW | MATCH_KW | CONST_KW | STATIC_KW | MUT_KW | UNSAFE_KW
             | TYPE_KW | REF_KW | LET_KW | MOVE_KW | RETURN_KW | TRY_KW | BOX_KW | AWAIT_KW
-            | AUTO_KW | DEFAULT_KW | EXISTENTIAL_KW | UNION_KW => true,
+            | MACRO_KW | AUTO_KW | DEFAULT_KW | EXISTENTIAL_KW | UNION_KW => true,
             _ => false,
         }
     }
@@ -314,6 +317,7 @@ impl SyntaxKind {
             "try" => TRY_KW,
             "box" => BOX_KW,
             "await" => AWAIT_KW,
+            "macro" => MACRO_KW,
             _ => return None,
         };
         Some(kw)
@@ -628,6 +632,9 @@ macro_rules! T {
     ( await ) => {
         $crate::SyntaxKind::AWAIT_KW
     };
+    ( macro ) => {
+        $crate::SyntaxKind::MACRO_KW
+    };
     ( auto ) => {
         $crate::SyntaxKind::AUTO_KW
     };
diff --git a/crates/ra_parser/src/token_set.rs b/crates/ra_parser/src/token_set.rs
index 2a6952c01..994017acf 100644
--- a/crates/ra_parser/src/token_set.rs
+++ b/crates/ra_parser/src/token_set.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! A bit-set of `SyntaxKind`s.
 
 use crate::SyntaxKind;
 
@@ -7,9 +7,7 @@ use crate::SyntaxKind;
 pub(crate) struct TokenSet(u128);
 
 impl TokenSet {
-    pub(crate) const fn empty() -> TokenSet {
-        TokenSet(0)
-    }
+    pub(crate) const EMPTY: TokenSet = TokenSet(0);
 
     pub(crate) const fn singleton(kind: SyntaxKind) -> TokenSet {
         TokenSet(mask(kind))
@@ -30,7 +28,7 @@ const fn mask(kind: SyntaxKind) -> u128 {
 
 #[macro_export]
 macro_rules! token_set {
-    ($($t:expr),*) => { TokenSet::empty()$(.union(TokenSet::singleton($t)))* };
+    ($($t:expr),*) => { TokenSet::EMPTY$(.union(TokenSet::singleton($t)))* };
     ($($t:expr),* ,) => { token_set!($($t),*) };
 }
 
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index 845b2221c..f260c40a3 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -217,7 +217,7 @@ fn print(
     total: Option<Duration>,
 ) {
     let mut last = 0;
-    let indent = repeat("    ").take(lvl + 1).collect::<String>();
+    let indent = repeat("    ").take(lvl).collect::<String>();
     // We output hierarchy for long calls, but sum up all short calls
     let mut short = Vec::new();
     let mut accounted_for = Duration::default();
@@ -227,7 +227,7 @@ fn print(
         }
         accounted_for += duration;
         if duration >= longer_than {
-            writeln!(out, "{} {:6}ms - {}", indent, duration.as_millis(), msg)
+            writeln!(out, "{}{:5}ms - {}", indent, duration.as_millis(), msg)
                 .expect("printing profiling info to stdout");
 
             print(lvl + 1, &msgs[last..i], out, longer_than, Some(duration));
@@ -245,14 +245,14 @@ fn print(
             count += 1;
             total_duration += *time;
         });
-        writeln!(out, "{} {:6}ms - {} ({} calls)", indent, total_duration.as_millis(), msg, count)
+        writeln!(out, "{}{:5}ms - {} ({} calls)", indent, total_duration.as_millis(), msg, count)
             .expect("printing profiling info to stdout");
     }
 
     if let Some(total) = total {
         if let Some(unaccounted) = total.checked_sub(accounted_for) {
             if unaccounted >= longer_than && last > 0 {
-                writeln!(out, "{} {:6}ms - ???", indent, unaccounted.as_millis())
+                writeln!(out, "{}{:5}ms - ???", indent, unaccounted.as_millis())
                     .expect("printing profiling info to stdout");
             }
         }
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 351997dcd..c862d3912 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -6,6 +6,7 @@ use cargo_metadata::{CargoOpt, MetadataCommand};
 use ra_arena::{impl_arena_id, Arena, RawId};
 use ra_db::Edition;
 use rustc_hash::FxHashMap;
+use serde::Deserialize;
 
 use crate::Result;
 
@@ -23,6 +24,26 @@ pub struct CargoWorkspace {
     pub(crate) workspace_root: PathBuf,
 }
 
+#[derive(Deserialize, Clone, Debug, PartialEq, Eq)]
+#[serde(rename_all = "camelCase", default)]
+pub struct CargoFeatures {
+    /// Do not activate the `default` feature.
+    pub no_default_features: bool,
+
+    /// Activate all available features
+    pub all_features: bool,
+
+    /// List of features to activate.
+    /// This will be ignored if `cargo_all_features` is true.
+    pub features: Vec<String>,
+}
+
+impl Default for CargoFeatures {
+    fn default() -> Self {
+        CargoFeatures { no_default_features: false, all_features: true, features: Vec::new() }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct Package(RawId);
 impl_arena_id!(Package);
@@ -132,9 +153,21 @@ impl Target {
 }
 
 impl CargoWorkspace {
-    pub fn from_cargo_metadata(cargo_toml: &Path) -> Result<CargoWorkspace> {
+    pub fn from_cargo_metadata(
+        cargo_toml: &Path,
+        cargo_features: &CargoFeatures,
+    ) -> Result<CargoWorkspace> {
         let mut meta = MetadataCommand::new();
-        meta.manifest_path(cargo_toml).features(CargoOpt::AllFeatures);
+        meta.manifest_path(cargo_toml);
+        if cargo_features.all_features {
+            meta.features(CargoOpt::AllFeatures);
+        } else if cargo_features.no_default_features {
+            // FIXME: `NoDefaultFeatures` is mutual exclusive with `SomeFeatures`
+            // https://github.com/oli-obk/cargo_metadata/issues/79
+            meta.features(CargoOpt::NoDefaultFeatures);
+        } else {
+            meta.features(CargoOpt::SomeFeatures(cargo_features.features.clone()));
+        }
         if let Some(parent) = cargo_toml.parent() {
             meta.current_dir(parent);
         }
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 55ff4d6ef..d71b7031a 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -18,7 +18,7 @@ use rustc_hash::FxHashMap;
 use serde_json::from_reader;
 
 pub use crate::{
-    cargo_workspace::{CargoWorkspace, Package, Target, TargetKind},
+    cargo_workspace::{CargoFeatures, CargoWorkspace, Package, Target, TargetKind},
     json_project::JsonProject,
     sysroot::Sysroot,
 };
@@ -60,11 +60,15 @@ impl PackageRoot {
 }
 
 impl ProjectWorkspace {
-    pub fn discover(path: &Path) -> Result<ProjectWorkspace> {
-        ProjectWorkspace::discover_with_sysroot(path, true)
+    pub fn discover(path: &Path, cargo_features: &CargoFeatures) -> Result<ProjectWorkspace> {
+        ProjectWorkspace::discover_with_sysroot(path, true, cargo_features)
     }
 
-    pub fn discover_with_sysroot(path: &Path, with_sysroot: bool) -> Result<ProjectWorkspace> {
+    pub fn discover_with_sysroot(
+        path: &Path,
+        with_sysroot: bool,
+        cargo_features: &CargoFeatures,
+    ) -> Result<ProjectWorkspace> {
         match find_rust_project_json(path) {
             Some(json_path) => {
                 let file = File::open(json_path)?;
@@ -73,7 +77,7 @@ impl ProjectWorkspace {
             }
             None => {
                 let cargo_toml = find_cargo_toml(path)?;
-                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml)?;
+                let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_features)?;
                 let sysroot =
                     if with_sysroot { Sysroot::discover(&cargo_toml)? } else { Sysroot::default() };
                 Ok(ProjectWorkspace::Cargo { cargo, sysroot })
diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index 5db2b58c0..b6ebb129d 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -12,19 +12,20 @@ doctest = false
 
 [dependencies]
 itertools = "0.8.0"
-rowan = "0.7.0"
+rowan = "0.8.0"
 rustc_lexer = "0.1.0"
 rustc-hash = "1.0.1"
 arrayvec = "0.5.1"
 once_cell = "1.2.0"
 
+ra_text_edit = { path = "../ra_text_edit" }
+ra_parser = { path = "../ra_parser" }
+
 # This crate transitively depends on `smol_str` via `rowan`.
 # ideally, `serde` should be enabled by `ra_lsp_server`, but we enable it here
 # to reduce number of compilations
 smol_str = { version = "0.1.12", features = ["serde"] }
-
-ra_text_edit = { path = "../ra_text_edit" }
-ra_parser = { path = "../ra_parser" }
+serde = { version = "1", features = ["derive"] }
 
 [dev-dependencies]
 test_utils = { path = "../test_utils" }
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 1c075082a..e4061e994 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -140,13 +140,13 @@ pub fn insert_children(
     });
 
     let new_children = match &position {
-        InsertPosition::First => to_insert.chain(old_children).collect::<Box<[_]>>(),
-        InsertPosition::Last => old_children.chain(to_insert).collect::<Box<[_]>>(),
+        InsertPosition::First => to_insert.chain(old_children).collect::<Vec<_>>(),
+        InsertPosition::Last => old_children.chain(to_insert).collect::<Vec<_>>(),
         InsertPosition::Before(anchor) | InsertPosition::After(anchor) => {
             let take_anchor = if let InsertPosition::After(_) = position { 1 } else { 0 };
             let split_at = position_of_child(parent, anchor.clone()) + take_anchor;
             let before = old_children.by_ref().take(split_at).collect::<Vec<_>>();
-            before.into_iter().chain(to_insert).chain(old_children).collect::<Box<[_]>>()
+            before.into_iter().chain(to_insert).chain(old_children).collect::<Vec<_>>()
         }
     };
 
@@ -174,7 +174,7 @@ pub fn replace_children(
         .into_iter()
         .chain(to_insert.map(to_green_element))
         .chain(old_children.skip(end + 1 - start))
-        .collect::<Box<[_]>>();
+        .collect::<Vec<_>>();
     with_children(parent, new_children)
 }
 
@@ -187,7 +187,7 @@ pub fn replace_descendants(
     map: &FxHashMap<SyntaxElement, SyntaxElement>,
 ) -> SyntaxNode {
     //  FIXME: this could be made much faster.
-    let new_children = parent.children_with_tokens().map(|it| go(map, it)).collect::<Box<[_]>>();
+    let new_children = parent.children_with_tokens().map(|it| go(map, it)).collect::<Vec<_>>();
     return with_children(parent, new_children);
 
     fn go(
@@ -211,7 +211,7 @@ pub fn replace_descendants(
 
 fn with_children(
     parent: &SyntaxNode,
-    new_children: Box<[NodeOrToken<rowan::GreenNode, rowan::GreenToken>]>,
+    new_children: Vec<NodeOrToken<rowan::GreenNode, rowan::GreenToken>>,
 ) -> SyntaxNode {
     let len = new_children.iter().map(|it| it.text_len()).sum::<TextUnit>();
     let new_node =
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 95bf9db14..ae5d63927 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -104,7 +104,7 @@ impl ast::ItemList {
             }
         };
 
-        let indent = leading_indent(self.syntax()).unwrap_or("".into());
+        let indent = leading_indent(self.syntax()).unwrap_or_default();
         let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
         let to_insert = iter::once(ws.ws().into());
         match existing_ws {
@@ -133,7 +133,7 @@ impl ast::RecordFieldList {
         let space = if is_multiline {
             ws = tokens::WsBuilder::new(&format!(
                 "\n{}    ",
-                leading_indent(self.syntax()).unwrap_or("".into())
+                leading_indent(self.syntax()).unwrap_or_default()
             ));
             ws.ws()
         } else {
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index c06076e3d..9f9d6e63c 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -312,6 +312,7 @@ impl AstNode for Block {
     }
 }
 impl ast::AttrsOwner for Block {}
+impl ast::ModuleItemOwner for Block {}
 impl Block {
     pub fn statements(&self) -> AstChildren<Stmt> {
         AstChildren::new(&self.syntax)
@@ -550,6 +551,36 @@ impl ConstDef {
     }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct ConstParam {
+    pub(crate) syntax: SyntaxNode,
+}
+impl AstNode for ConstParam {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            CONST_PARAM => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        if Self::can_cast(syntax.kind()) {
+            Some(Self { syntax })
+        } else {
+            None
+        }
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        &self.syntax
+    }
+}
+impl ast::NameOwner for ConstParam {}
+impl ast::AttrsOwner for ConstParam {}
+impl ast::TypeAscriptionOwner for ConstParam {}
+impl ConstParam {
+    pub fn default_val(&self) -> Option<Expr> {
+        AstChildren::new(&self.syntax).next()
+    }
+}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct ContinueExpr {
     pub(crate) syntax: SyntaxNode,
 }
@@ -1425,6 +1456,9 @@ impl LambdaExpr {
     pub fn param_list(&self) -> Option<ParamList> {
         AstChildren::new(&self.syntax).next()
     }
+    pub fn ret_type(&self) -> Option<RetType> {
+        AstChildren::new(&self.syntax).next()
+    }
     pub fn body(&self) -> Option<Expr> {
         AstChildren::new(&self.syntax).next()
     }
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index 40db570da..04a5408fe 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -168,8 +168,7 @@ pub fn let_stmt(pattern: ast::Pat, initializer: Option<ast::Expr>) -> ast::LetSt
 
 fn ast_from_text<N: AstNode>(text: &str) -> N {
     let parse = SourceFile::parse(text);
-    let res = parse.tree().syntax().descendants().find_map(N::cast).unwrap();
-    res
+    parse.tree().syntax().descendants().find_map(N::cast).unwrap()
 }
 
 pub mod tokens {
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index d1be40abe..08aafb610 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -94,7 +94,8 @@ Grammar(
         "return",
         "try",
         "box",
-        "await"
+        "await",
+        "macro"
     ],
     contextual_keywords: [
         "auto",
@@ -140,6 +141,7 @@ Grammar(
         "TYPE_ALIAS_DEF",
         "MACRO_CALL",
         "TOKEN_TREE",
+        "MACRO_DEF",
 
         "PAREN_TYPE",
         "TUPLE_TYPE",
@@ -243,6 +245,7 @@ Grammar(
         "TYPE_PARAM_LIST",
         "LIFETIME_PARAM",
         "TYPE_PARAM",
+        "CONST_PARAM",
         "TYPE_ARG_LIST",
         "LIFETIME_ARG",
         "TYPE_ARG",
@@ -426,7 +429,7 @@ Grammar(
         "PathExpr": (options: ["Path"]),
         "LambdaExpr": (
             options: [
-                "ParamList",
+                "ParamList", "RetType",
                 ["body", "Expr"],
             ]
         ),
@@ -602,6 +605,10 @@ Grammar(
             options: [("default_type", "TypeRef")],
             traits: ["NameOwner", "AttrsOwner", "TypeBoundsOwner"],
         ),
+        "ConstParam": (
+            options: [("default_val", "Expr")],
+            traits: ["NameOwner", "AttrsOwner", "TypeAscriptionOwner"],
+        ),
         "LifetimeParam": (
             traits: ["AttrsOwner"],
         ),
@@ -653,6 +660,7 @@ Grammar(
             ],
             traits: [
                 "AttrsOwner",
+                "ModuleItemOwner",
             ]
         ),
         "ParamList": (
@@ -664,14 +672,14 @@ Grammar(
         "SelfParam": (
             traits: [
                 "TypeAscriptionOwner",
-                                "AttrsOwner",
+                "AttrsOwner",
             ]
         ),
         "Param": (
             options: [ "Pat" ],
             traits: [
                 "TypeAscriptionOwner",
-                                "AttrsOwner",
+                "AttrsOwner",
             ]
         ),
         "UseItem": (
diff --git a/crates/ra_syntax/src/ptr.rs b/crates/ra_syntax/src/ptr.rs
index e049fce61..db6230aab 100644
--- a/crates/ra_syntax/src/ptr.rs
+++ b/crates/ra_syntax/src/ptr.rs
@@ -1,6 +1,10 @@
 //! FIXME: write short doc here
 
-use std::{iter::successors, marker::PhantomData};
+use std::{
+    hash::{Hash, Hasher},
+    iter::successors,
+    marker::PhantomData,
+};
 
 use crate::{AstNode, SyntaxKind, SyntaxNode, TextRange};
 
@@ -43,7 +47,7 @@ impl SyntaxNodePtr {
 }
 
 /// Like `SyntaxNodePtr`, but remembers the type of node
-#[derive(Debug, Hash)]
+#[derive(Debug)]
 pub struct AstPtr<N: AstNode> {
     raw: SyntaxNodePtr,
     _ty: PhantomData<fn() -> N>,
@@ -64,6 +68,12 @@ impl<N: AstNode> PartialEq for AstPtr<N> {
     }
 }
 
+impl<N: AstNode> Hash for AstPtr<N> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.raw.hash(state)
+    }
+}
+
 impl<N: AstNode> AstPtr<N> {
     pub fn new(node: &N) -> AstPtr<N> {
         AstPtr { raw: SyntaxNodePtr::new(node.syntax()), _ty: PhantomData }
diff --git a/crates/ra_syntax/src/syntax_node.rs b/crates/ra_syntax/src/syntax_node.rs
index b2f5b8c64..041c6ea8d 100644
--- a/crates/ra_syntax/src/syntax_node.rs
+++ b/crates/ra_syntax/src/syntax_node.rs
@@ -40,7 +40,7 @@ pub use rowan::{Direction, NodeOrToken};
 
 pub struct SyntaxTreeBuilder {
     errors: Vec<SyntaxError>,
-    inner: GreenNodeBuilder,
+    inner: GreenNodeBuilder<'static>,
 }
 
 impl Default for SyntaxTreeBuilder {
diff --git a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt b/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt
deleted file mode 100644
index c5be73a5a..000000000
--- a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt
+++ /dev/null
@@ -1,328 +0,0 @@
-SOURCE_FILE@[0; 349)
-  MACRO_CALL@[0; 41)
-    PATH@[0; 5)
-      PATH_SEGMENT@[0; 5)
-        NAME_REF@[0; 5)
-          IDENT@[0; 5) "macro"
-    WHITESPACE@[5; 6) " "
-    NAME@[6; 21)
-      IDENT@[6; 21) "parse_use_trees"
-    TOKEN_TREE@[21; 41)
-      L_PAREN@[21; 22) "("
-      DOLLAR@[22; 23) "$"
-      TOKEN_TREE@[23; 32)
-        L_PAREN@[23; 24) "("
-        DOLLAR@[24; 25) "$"
-        IDENT@[25; 26) "s"
-        COLON@[26; 27) ":"
-        IDENT@[27; 31) "expr"
-        R_PAREN@[31; 32) ")"
-      COMMA@[32; 33) ","
-      STAR@[33; 34) "*"
-      WHITESPACE@[34; 35) " "
-      DOLLAR@[35; 36) "$"
-      TOKEN_TREE@[36; 39)
-        L_PAREN@[36; 37) "("
-        COMMA@[37; 38) ","
-        R_PAREN@[38; 39) ")"
-      STAR@[39; 40) "*"
-      R_PAREN@[40; 41) ")"
-  WHITESPACE@[41; 42) " "
-  ERROR@[42; 93)
-    L_CURLY@[42; 43) "{"
-    WHITESPACE@[43; 48) "\n    "
-    MACRO_CALL@[48; 91)
-      PATH@[48; 51)
-        PATH_SEGMENT@[48; 51)
-          NAME_REF@[48; 51)
-            IDENT@[48; 51) "vec"
-      EXCL@[51; 52) "!"
-      TOKEN_TREE@[52; 91)
-        L_BRACK@[52; 53) "["
-        WHITESPACE@[53; 62) "\n        "
-        DOLLAR@[62; 63) "$"
-        TOKEN_TREE@[63; 84)
-          L_PAREN@[63; 64) "("
-          IDENT@[64; 78) "parse_use_tree"
-          TOKEN_TREE@[78; 82)
-            L_PAREN@[78; 79) "("
-            DOLLAR@[79; 80) "$"
-            IDENT@[80; 81) "s"
-            R_PAREN@[81; 82) ")"
-          COMMA@[82; 83) ","
-          R_PAREN@[83; 84) ")"
-        STAR@[84; 85) "*"
-        WHITESPACE@[85; 90) "\n    "
-        R_BRACK@[90; 91) "]"
-    WHITESPACE@[91; 92) "\n"
-    R_CURLY@[92; 93) "}"
-  WHITESPACE@[93; 95) "\n\n"
-  FN_DEF@[95; 348)
-    ATTR@[95; 102)
-      POUND@[95; 96) "#"
-      L_BRACK@[96; 97) "["
-      PATH@[97; 101)
-        PATH_SEGMENT@[97; 101)
-          NAME_REF@[97; 101)
-            IDENT@[97; 101) "test"
-      R_BRACK@[101; 102) "]"
-    WHITESPACE@[102; 103) "\n"
-    FN_KW@[103; 105) "fn"
-    WHITESPACE@[105; 106) " "
-    NAME@[106; 125)
-      IDENT@[106; 125) "test_use_tree_merge"
-    PARAM_LIST@[125; 127)
-      L_PAREN@[125; 126) "("
-      R_PAREN@[126; 127) ")"
-    WHITESPACE@[127; 128) " "
-    BLOCK_EXPR@[128; 348)
-      BLOCK@[128; 348)
-        L_CURLY@[128; 129) "{"
-        WHITESPACE@[129; 134) "\n    "
-        EXPR_STMT@[134; 139)
-          PATH_EXPR@[134; 139)
-            PATH@[134; 139)
-              PATH_SEGMENT@[134; 139)
-                NAME_REF@[134; 139)
-                  IDENT@[134; 139) "macro"
-        WHITESPACE@[139; 140) " "
-        EXPR_STMT@[140; 154)
-          CALL_EXPR@[140; 154)
-            PATH_EXPR@[140; 150)
-              PATH@[140; 150)
-                PATH_SEGMENT@[140; 150)
-                  NAME_REF@[140; 150)
-                    IDENT@[140; 150) "test_merge"
-            ARG_LIST@[150; 154)
-              L_PAREN@[150; 151) "("
-              ARRAY_EXPR@[151; 154)
-                L_BRACK@[151; 152) "["
-                ERROR@[152; 153)
-                  DOLLAR@[152; 153) "$"
-                PAREN_EXPR@[153; 154)
-                  L_PAREN@[153; 154) "("
-        EXPR_STMT@[154; 155)
-          ERROR@[154; 155)
-            DOLLAR@[154; 155) "$"
-        EXPR_STMT@[155; 160)
-          PATH_EXPR@[155; 160)
-            PATH@[155; 160)
-              PATH_SEGMENT@[155; 160)
-                NAME_REF@[155; 160)
-                  IDENT@[155; 160) "input"
-        EXPR_STMT@[160; 161)
-          ERROR@[160; 161)
-            COLON@[160; 161) ":"
-        EXPR_STMT@[161; 165)
-          PATH_EXPR@[161; 165)
-            PATH@[161; 165)
-              PATH_SEGMENT@[161; 165)
-                NAME_REF@[161; 165)
-                  IDENT@[161; 165) "expr"
-        EXPR_STMT@[165; 166)
-          ERROR@[165; 166)
-            R_PAREN@[165; 166) ")"
-        EXPR_STMT@[166; 167)
-          ERROR@[166; 167)
-            COMMA@[166; 167) ","
-        EXPR_STMT@[167; 170)
-          PREFIX_EXPR@[167; 170)
-            STAR@[167; 168) "*"
-            WHITESPACE@[168; 169) " "
-            ERROR@[169; 170)
-              DOLLAR@[169; 170) "$"
-        EXPR_STMT@[170; 171)
-          PAREN_EXPR@[170; 171)
-            L_PAREN@[170; 171) "("
-        EXPR_STMT@[171; 172)
-          ERROR@[171; 172)
-            COMMA@[171; 172) ","
-        EXPR_STMT@[172; 173)
-          ERROR@[172; 173)
-            R_PAREN@[172; 173) ")"
-        EXPR_STMT@[173; 175)
-          PREFIX_EXPR@[173; 175)
-            STAR@[173; 174) "*"
-            ERROR@[174; 175)
-              R_BRACK@[174; 175) "]"
-        EXPR_STMT@[175; 176)
-          ERROR@[175; 176)
-            COMMA@[175; 176) ","
-        WHITESPACE@[176; 177) " "
-        EXPR_STMT@[177; 180)
-          ARRAY_EXPR@[177; 180)
-            L_BRACK@[177; 178) "["
-            ERROR@[178; 179)
-              DOLLAR@[178; 179) "$"
-            PAREN_EXPR@[179; 180)
-              L_PAREN@[179; 180) "("
-        EXPR_STMT@[180; 181)
-          ERROR@[180; 181)
-            DOLLAR@[180; 181) "$"
-        EXPR_STMT@[181; 187)
-          PATH_EXPR@[181; 187)
-            PATH@[181; 187)
-              PATH_SEGMENT@[181; 187)
-                NAME_REF@[181; 187)
-                  IDENT@[181; 187) "output"
-        EXPR_STMT@[187; 188)
-          ERROR@[187; 188)
-            COLON@[187; 188) ":"
-        EXPR_STMT@[188; 192)
-          PATH_EXPR@[188; 192)
-            PATH@[188; 192)
-              PATH_SEGMENT@[188; 192)
-                NAME_REF@[188; 192)
-                  IDENT@[188; 192) "expr"
-        EXPR_STMT@[192; 193)
-          ERROR@[192; 193)
-            R_PAREN@[192; 193) ")"
-        EXPR_STMT@[193; 194)
-          ERROR@[193; 194)
-            COMMA@[193; 194) ","
-        EXPR_STMT@[194; 197)
-          PREFIX_EXPR@[194; 197)
-            STAR@[194; 195) "*"
-            WHITESPACE@[195; 196) " "
-            ERROR@[196; 197)
-              DOLLAR@[196; 197) "$"
-        EXPR_STMT@[197; 198)
-          PAREN_EXPR@[197; 198)
-            L_PAREN@[197; 198) "("
-        EXPR_STMT@[198; 199)
-          ERROR@[198; 199)
-            COMMA@[198; 199) ","
-        EXPR_STMT@[199; 200)
-          ERROR@[199; 200)
-            R_PAREN@[199; 200) ")"
-        EXPR_STMT@[200; 202)
-          PREFIX_EXPR@[200; 202)
-            STAR@[200; 201) "*"
-            ERROR@[201; 202)
-              R_BRACK@[201; 202) "]"
-        EXPR_STMT@[202; 203)
-          ERROR@[202; 203)
-            R_PAREN@[202; 203) ")"
-        WHITESPACE@[203; 204) " "
-        BLOCK_EXPR@[204; 346)
-          BLOCK@[204; 346)
-            L_CURLY@[204; 205) "{"
-            WHITESPACE@[205; 214) "\n        "
-            EXPR_STMT@[214; 340)
-              MACRO_CALL@[214; 339)
-                PATH@[214; 223)
-                  PATH_SEGMENT@[214; 223)
-                    NAME_REF@[214; 223)
-                      IDENT@[214; 223) "assert_eq"
-                EXCL@[223; 224) "!"
-                TOKEN_TREE@[224; 339)
-                  L_PAREN@[224; 225) "("
-                  WHITESPACE@[225; 238) "\n            "
-                  IDENT@[238; 253) "merge_use_trees"
-                  TOKEN_TREE@[253; 284)
-                    L_PAREN@[253; 254) "("
-                    IDENT@[254; 269) "parse_use_trees"
-                    EXCL@[269; 270) "!"
-                    TOKEN_TREE@[270; 283)
-                      L_PAREN@[270; 271) "("
-                      DOLLAR@[271; 272) "$"
-                      TOKEN_TREE@[272; 281)
-                        L_PAREN@[272; 273) "("
-                        DOLLAR@[273; 274) "$"
-                        IDENT@[274; 279) "input"
-                        COMMA@[279; 280) ","
-                        R_PAREN@[280; 281) ")"
-                      STAR@[281; 282) "*"
-                      R_PAREN@[282; 283) ")"
-                    R_PAREN@[283; 284) ")"
-                  COMMA@[284; 285) ","
-                  WHITESPACE@[285; 298) "\n            "
-                  IDENT@[298; 313) "parse_use_trees"
-                  EXCL@[313; 314) "!"
-                  TOKEN_TREE@[314; 328)
-                    L_PAREN@[314; 315) "("
-                    DOLLAR@[315; 316) "$"
-                    TOKEN_TREE@[316; 326)
-                      L_PAREN@[316; 317) "("
-                      DOLLAR@[317; 318) "$"
-                      IDENT@[318; 324) "output"
-                      COMMA@[324; 325) ","
-                      R_PAREN@[325; 326) ")"
-                    STAR@[326; 327) "*"
-                    R_PAREN@[327; 328) ")"
-                  COMMA@[328; 329) ","
-                  WHITESPACE@[329; 338) "\n        "
-                  R_PAREN@[338; 339) ")"
-              SEMI@[339; 340) ";"
-            WHITESPACE@[340; 345) "\n    "
-            R_CURLY@[345; 346) "}"
-        WHITESPACE@[346; 347) "\n"
-        R_CURLY@[347; 348) "}"
-  WHITESPACE@[348; 349) "\n"
-error 5: expected EXCL
-error 41: expected SEMI
-error 42: expected an item
-error 139: expected SEMI
-error 152: expected expression
-error 153: expected COMMA
-error 154: expected expression
-error 154: expected R_PAREN
-error 154: expected COMMA
-error 154: expected expression
-error 154: expected R_BRACK
-error 154: expected COMMA
-error 154: expected SEMI
-error 154: expected expression
-error 155: expected SEMI
-error 160: expected SEMI
-error 160: expected expression
-error 161: expected SEMI
-error 165: expected SEMI
-error 165: expected expression
-error 166: expected SEMI
-error 166: expected expression
-error 167: expected SEMI
-error 169: expected expression
-error 170: expected SEMI
-error 171: expected expression
-error 171: expected R_PAREN
-error 171: expected SEMI
-error 171: expected expression
-error 172: expected SEMI
-error 172: expected expression
-error 173: expected SEMI
-error 174: expected expression
-error 175: expected SEMI
-error 175: expected expression
-error 176: expected SEMI
-error 178: expected expression
-error 179: expected COMMA
-error 180: expected expression
-error 180: expected R_PAREN
-error 180: expected COMMA
-error 180: expected expression
-error 180: expected R_BRACK
-error 180: expected SEMI
-error 180: expected expression
-error 181: expected SEMI
-error 187: expected SEMI
-error 187: expected expression
-error 188: expected SEMI
-error 192: expected SEMI
-error 192: expected expression
-error 193: expected SEMI
-error 193: expected expression
-error 194: expected SEMI
-error 196: expected expression
-error 197: expected SEMI
-error 198: expected expression
-error 198: expected R_PAREN
-error 198: expected SEMI
-error 198: expected expression
-error 199: expected SEMI
-error 199: expected expression
-error 200: expected SEMI
-error 201: expected expression
-error 202: expected SEMI
-error 202: expected expression
-error 203: expected SEMI
diff --git a/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.rs b/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.rs
new file mode 100644
index 000000000..a2f74bd87
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.rs
@@ -0,0 +1,5 @@
+fn foo() -> i32 {
+    [1, 2, 3].iter()
+        .map(|it|)
+        .max::<i32>();
+}
diff --git a/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.txt b/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.txt
new file mode 100644
index 000000000..d1544634c
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0039_lambda_recovery.txt
@@ -0,0 +1,83 @@
+SOURCE_FILE@[0; 83)
+  FN_DEF@[0; 82)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    RET_TYPE@[9; 15)
+      THIN_ARROW@[9; 11) "->"
+      WHITESPACE@[11; 12) " "
+      PATH_TYPE@[12; 15)
+        PATH@[12; 15)
+          PATH_SEGMENT@[12; 15)
+            NAME_REF@[12; 15)
+              IDENT@[12; 15) "i32"
+    WHITESPACE@[15; 16) " "
+    BLOCK_EXPR@[16; 82)
+      BLOCK@[16; 82)
+        L_CURLY@[16; 17) "{"
+        WHITESPACE@[17; 22) "\n    "
+        EXPR_STMT@[22; 80)
+          METHOD_CALL_EXPR@[22; 79)
+            METHOD_CALL_EXPR@[22; 57)
+              METHOD_CALL_EXPR@[22; 38)
+                ARRAY_EXPR@[22; 31)
+                  L_BRACK@[22; 23) "["
+                  LITERAL@[23; 24)
+                    INT_NUMBER@[23; 24) "1"
+                  COMMA@[24; 25) ","
+                  WHITESPACE@[25; 26) " "
+                  LITERAL@[26; 27)
+                    INT_NUMBER@[26; 27) "2"
+                  COMMA@[27; 28) ","
+                  WHITESPACE@[28; 29) " "
+                  LITERAL@[29; 30)
+                    INT_NUMBER@[29; 30) "3"
+                  R_BRACK@[30; 31) "]"
+                DOT@[31; 32) "."
+                NAME_REF@[32; 36)
+                  IDENT@[32; 36) "iter"
+                ARG_LIST@[36; 38)
+                  L_PAREN@[36; 37) "("
+                  R_PAREN@[37; 38) ")"
+              WHITESPACE@[38; 47) "\n        "
+              DOT@[47; 48) "."
+              NAME_REF@[48; 51)
+                IDENT@[48; 51) "map"
+              ARG_LIST@[51; 57)
+                L_PAREN@[51; 52) "("
+                LAMBDA_EXPR@[52; 56)
+                  PARAM_LIST@[52; 56)
+                    PIPE@[52; 53) "|"
+                    PARAM@[53; 55)
+                      BIND_PAT@[53; 55)
+                        NAME@[53; 55)
+                          IDENT@[53; 55) "it"
+                    PIPE@[55; 56) "|"
+                R_PAREN@[56; 57) ")"
+            WHITESPACE@[57; 66) "\n        "
+            DOT@[66; 67) "."
+            NAME_REF@[67; 70)
+              IDENT@[67; 70) "max"
+            TYPE_ARG_LIST@[70; 77)
+              COLONCOLON@[70; 72) "::"
+              L_ANGLE@[72; 73) "<"
+              TYPE_ARG@[73; 76)
+                PATH_TYPE@[73; 76)
+                  PATH@[73; 76)
+                    PATH_SEGMENT@[73; 76)
+                      NAME_REF@[73; 76)
+                        IDENT@[73; 76) "i32"
+              R_ANGLE@[76; 77) ">"
+            ARG_LIST@[77; 79)
+              L_PAREN@[77; 78) "("
+              R_PAREN@[78; 79) ")"
+          SEMI@[79; 80) ";"
+        WHITESPACE@[80; 81) "\n"
+        R_CURLY@[81; 82) "}"
+  WHITESPACE@[82; 83) "\n"
+error 56: expected expression
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt b/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
index 4a714ad6b..b05ccc0ed 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0129_marco_pat.txt
@@ -16,11 +16,10 @@ SOURCE_FILE@[0; 33)
           LET_KW@[16; 19) "let"
           WHITESPACE@[19; 20) " "
           MACRO_CALL@[20; 25)
-            PATH_PAT@[20; 21)
-              PATH@[20; 21)
-                PATH_SEGMENT@[20; 21)
-                  NAME_REF@[20; 21)
-                    IDENT@[20; 21) "m"
+            PATH@[20; 21)
+              PATH_SEGMENT@[20; 21)
+                NAME_REF@[20; 21)
+                  IDENT@[20; 21) "m"
             EXCL@[21; 22) "!"
             TOKEN_TREE@[22; 25)
               L_PAREN@[22; 23) "("
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.rs b/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.rs
new file mode 100644
index 000000000..8cdb3b703
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.rs
@@ -0,0 +1 @@
+struct S<const N: u32>;
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.txt b/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.txt
new file mode 100644
index 000000000..f81de7bac
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0147_const_param.txt
@@ -0,0 +1,23 @@
+SOURCE_FILE@[0; 24)
+  STRUCT_DEF@[0; 23)
+    STRUCT_KW@[0; 6) "struct"
+    WHITESPACE@[6; 7) " "
+    NAME@[7; 8)
+      IDENT@[7; 8) "S"
+    TYPE_PARAM_LIST@[8; 22)
+      L_ANGLE@[8; 9) "<"
+      CONST_PARAM@[9; 21)
+        CONST_KW@[9; 14) "const"
+        WHITESPACE@[14; 15) " "
+        NAME@[15; 16)
+          IDENT@[15; 16) "N"
+        COLON@[16; 17) ":"
+        WHITESPACE@[17; 18) " "
+        PATH_TYPE@[18; 21)
+          PATH@[18; 21)
+            PATH_SEGMENT@[18; 21)
+              NAME_REF@[18; 21)
+                IDENT@[18; 21) "u32"
+      R_ANGLE@[21; 22) ">"
+    SEMI@[22; 23) ";"
+  WHITESPACE@[23; 24) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.rs b/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.rs
new file mode 100644
index 000000000..319a4e2aa
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.rs
@@ -0,0 +1,2 @@
+macro m { ($i:ident) => {} }
+macro m($i:ident) {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.txt b/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.txt
new file mode 100644
index 000000000..3556099bd
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0147_macro_def.txt
@@ -0,0 +1,45 @@
+SOURCE_FILE@[0; 50)
+  MACRO_DEF@[0; 28)
+    MACRO_KW@[0; 5) "macro"
+    WHITESPACE@[5; 6) " "
+    NAME@[6; 7)
+      IDENT@[6; 7) "m"
+    WHITESPACE@[7; 8) " "
+    TOKEN_TREE@[8; 28)
+      L_CURLY@[8; 9) "{"
+      WHITESPACE@[9; 10) " "
+      TOKEN_TREE@[10; 20)
+        L_PAREN@[10; 11) "("
+        DOLLAR@[11; 12) "$"
+        IDENT@[12; 13) "i"
+        COLON@[13; 14) ":"
+        IDENT@[14; 19) "ident"
+        R_PAREN@[19; 20) ")"
+      WHITESPACE@[20; 21) " "
+      EQ@[21; 22) "="
+      R_ANGLE@[22; 23) ">"
+      WHITESPACE@[23; 24) " "
+      TOKEN_TREE@[24; 26)
+        L_CURLY@[24; 25) "{"
+        R_CURLY@[25; 26) "}"
+      WHITESPACE@[26; 27) " "
+      R_CURLY@[27; 28) "}"
+  WHITESPACE@[28; 29) "\n"
+  MACRO_DEF@[29; 49)
+    MACRO_KW@[29; 34) "macro"
+    WHITESPACE@[34; 35) " "
+    NAME@[35; 36)
+      IDENT@[35; 36) "m"
+    TOKEN_TREE@[36; 49)
+      TOKEN_TREE@[36; 46)
+        L_PAREN@[36; 37) "("
+        DOLLAR@[37; 38) "$"
+        IDENT@[38; 39) "i"
+        COLON@[39; 40) ":"
+        IDENT@[40; 45) "ident"
+        R_PAREN@[45; 46) ")"
+      WHITESPACE@[46; 47) " "
+      TOKEN_TREE@[47; 49)
+        L_CURLY@[47; 48) "{"
+        R_CURLY@[48; 49) "}"
+  WHITESPACE@[49; 50) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.rs b/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.rs
new file mode 100644
index 000000000..3b2be597f
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.rs
@@ -0,0 +1 @@
+pub macro m($:ident) {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.txt b/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.txt
new file mode 100644
index 000000000..cfd79d9c2
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0148_pub_macro_def.txt
@@ -0,0 +1,21 @@
+SOURCE_FILE@[0; 24)
+  MACRO_DEF@[0; 23)
+    VISIBILITY@[0; 3)
+      PUB_KW@[0; 3) "pub"
+    WHITESPACE@[3; 4) " "
+    MACRO_KW@[4; 9) "macro"
+    WHITESPACE@[9; 10) " "
+    NAME@[10; 11)
+      IDENT@[10; 11) "m"
+    TOKEN_TREE@[11; 23)
+      TOKEN_TREE@[11; 20)
+        L_PAREN@[11; 12) "("
+        DOLLAR@[12; 13) "$"
+        COLON@[13; 14) ":"
+        IDENT@[14; 19) "ident"
+        R_PAREN@[19; 20) ")"
+      WHITESPACE@[20; 21) " "
+      TOKEN_TREE@[21; 23)
+        L_CURLY@[21; 22) "{"
+        R_CURLY@[22; 23) "}"
+  WHITESPACE@[23; 24) "\n"
diff --git a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.rs b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.rs
index 781047ba1..781047ba1 100644
--- a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.rs
+++ b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.rs
diff --git a/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.txt b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.txt
new file mode 100644
index 000000000..2be523fc3
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0062_macro_2.0.txt
@@ -0,0 +1,176 @@
+SOURCE_FILE@[0; 349)
+  MACRO_DEF@[0; 93)
+    MACRO_KW@[0; 5) "macro"
+    WHITESPACE@[5; 6) " "
+    NAME@[6; 21)
+      IDENT@[6; 21) "parse_use_trees"
+    TOKEN_TREE@[21; 93)
+      TOKEN_TREE@[21; 41)
+        L_PAREN@[21; 22) "("
+        DOLLAR@[22; 23) "$"
+        TOKEN_TREE@[23; 32)
+          L_PAREN@[23; 24) "("
+          DOLLAR@[24; 25) "$"
+          IDENT@[25; 26) "s"
+          COLON@[26; 27) ":"
+          IDENT@[27; 31) "expr"
+          R_PAREN@[31; 32) ")"
+        COMMA@[32; 33) ","
+        STAR@[33; 34) "*"
+        WHITESPACE@[34; 35) " "
+        DOLLAR@[35; 36) "$"
+        TOKEN_TREE@[36; 39)
+          L_PAREN@[36; 37) "("
+          COMMA@[37; 38) ","
+          R_PAREN@[38; 39) ")"
+        STAR@[39; 40) "*"
+        R_PAREN@[40; 41) ")"
+      WHITESPACE@[41; 42) " "
+      TOKEN_TREE@[42; 93)
+        L_CURLY@[42; 43) "{"
+        WHITESPACE@[43; 48) "\n    "
+        IDENT@[48; 51) "vec"
+        EXCL@[51; 52) "!"
+        TOKEN_TREE@[52; 91)
+          L_BRACK@[52; 53) "["
+          WHITESPACE@[53; 62) "\n        "
+          DOLLAR@[62; 63) "$"
+          TOKEN_TREE@[63; 84)
+            L_PAREN@[63; 64) "("
+            IDENT@[64; 78) "parse_use_tree"
+            TOKEN_TREE@[78; 82)
+              L_PAREN@[78; 79) "("
+              DOLLAR@[79; 80) "$"
+              IDENT@[80; 81) "s"
+              R_PAREN@[81; 82) ")"
+            COMMA@[82; 83) ","
+            R_PAREN@[83; 84) ")"
+          STAR@[84; 85) "*"
+          WHITESPACE@[85; 90) "\n    "
+          R_BRACK@[90; 91) "]"
+        WHITESPACE@[91; 92) "\n"
+        R_CURLY@[92; 93) "}"
+  WHITESPACE@[93; 95) "\n\n"
+  FN_DEF@[95; 348)
+    ATTR@[95; 102)
+      POUND@[95; 96) "#"
+      L_BRACK@[96; 97) "["
+      PATH@[97; 101)
+        PATH_SEGMENT@[97; 101)
+          NAME_REF@[97; 101)
+            IDENT@[97; 101) "test"
+      R_BRACK@[101; 102) "]"
+    WHITESPACE@[102; 103) "\n"
+    FN_KW@[103; 105) "fn"
+    WHITESPACE@[105; 106) " "
+    NAME@[106; 125)
+      IDENT@[106; 125) "test_use_tree_merge"
+    PARAM_LIST@[125; 127)
+      L_PAREN@[125; 126) "("
+      R_PAREN@[126; 127) ")"
+    WHITESPACE@[127; 128) " "
+    BLOCK_EXPR@[128; 348)
+      BLOCK@[128; 348)
+        L_CURLY@[128; 129) "{"
+        WHITESPACE@[129; 134) "\n    "
+        MACRO_DEF@[134; 346)
+          MACRO_KW@[134; 139) "macro"
+          WHITESPACE@[139; 140) " "
+          NAME@[140; 150)
+            IDENT@[140; 150) "test_merge"
+          TOKEN_TREE@[150; 346)
+            TOKEN_TREE@[150; 203)
+              L_PAREN@[150; 151) "("
+              TOKEN_TREE@[151; 175)
+                L_BRACK@[151; 152) "["
+                DOLLAR@[152; 153) "$"
+                TOKEN_TREE@[153; 166)
+                  L_PAREN@[153; 154) "("
+                  DOLLAR@[154; 155) "$"
+                  IDENT@[155; 160) "input"
+                  COLON@[160; 161) ":"
+                  IDENT@[161; 165) "expr"
+                  R_PAREN@[165; 166) ")"
+                COMMA@[166; 167) ","
+                STAR@[167; 168) "*"
+                WHITESPACE@[168; 169) " "
+                DOLLAR@[169; 170) "$"
+                TOKEN_TREE@[170; 173)
+                  L_PAREN@[170; 171) "("
+                  COMMA@[171; 172) ","
+                  R_PAREN@[172; 173) ")"
+                STAR@[173; 174) "*"
+                R_BRACK@[174; 175) "]"
+              COMMA@[175; 176) ","
+              WHITESPACE@[176; 177) " "
+              TOKEN_TREE@[177; 202)
+                L_BRACK@[177; 178) "["
+                DOLLAR@[178; 179) "$"
+                TOKEN_TREE@[179; 193)
+                  L_PAREN@[179; 180) "("
+                  DOLLAR@[180; 181) "$"
+                  IDENT@[181; 187) "output"
+                  COLON@[187; 188) ":"
+                  IDENT@[188; 192) "expr"
+                  R_PAREN@[192; 193) ")"
+                COMMA@[193; 194) ","
+                STAR@[194; 195) "*"
+                WHITESPACE@[195; 196) " "
+                DOLLAR@[196; 197) "$"
+                TOKEN_TREE@[197; 200)
+                  L_PAREN@[197; 198) "("
+                  COMMA@[198; 199) ","
+                  R_PAREN@[199; 200) ")"
+                STAR@[200; 201) "*"
+                R_BRACK@[201; 202) "]"
+              R_PAREN@[202; 203) ")"
+            WHITESPACE@[203; 204) " "
+            TOKEN_TREE@[204; 346)
+              L_CURLY@[204; 205) "{"
+              WHITESPACE@[205; 214) "\n        "
+              IDENT@[214; 223) "assert_eq"
+              EXCL@[223; 224) "!"
+              TOKEN_TREE@[224; 339)
+                L_PAREN@[224; 225) "("
+                WHITESPACE@[225; 238) "\n            "
+                IDENT@[238; 253) "merge_use_trees"
+                TOKEN_TREE@[253; 284)
+                  L_PAREN@[253; 254) "("
+                  IDENT@[254; 269) "parse_use_trees"
+                  EXCL@[269; 270) "!"
+                  TOKEN_TREE@[270; 283)
+                    L_PAREN@[270; 271) "("
+                    DOLLAR@[271; 272) "$"
+                    TOKEN_TREE@[272; 281)
+                      L_PAREN@[272; 273) "("
+                      DOLLAR@[273; 274) "$"
+                      IDENT@[274; 279) "input"
+                      COMMA@[279; 280) ","
+                      R_PAREN@[280; 281) ")"
+                    STAR@[281; 282) "*"
+                    R_PAREN@[282; 283) ")"
+                  R_PAREN@[283; 284) ")"
+                COMMA@[284; 285) ","
+                WHITESPACE@[285; 298) "\n            "
+                IDENT@[298; 313) "parse_use_trees"
+                EXCL@[313; 314) "!"
+                TOKEN_TREE@[314; 328)
+                  L_PAREN@[314; 315) "("
+                  DOLLAR@[315; 316) "$"
+                  TOKEN_TREE@[316; 326)
+                    L_PAREN@[316; 317) "("
+                    DOLLAR@[317; 318) "$"
+                    IDENT@[318; 324) "output"
+                    COMMA@[324; 325) ","
+                    R_PAREN@[325; 326) ")"
+                  STAR@[326; 327) "*"
+                  R_PAREN@[327; 328) ")"
+                COMMA@[328; 329) ","
+                WHITESPACE@[329; 338) "\n        "
+                R_PAREN@[338; 339) ")"
+              SEMI@[339; 340) ";"
+              WHITESPACE@[340; 345) "\n    "
+              R_CURLY@[345; 346) "}"
+        WHITESPACE@[346; 347) "\n"
+        R_CURLY@[347; 348) "}"
+  WHITESPACE@[348; 349) "\n"
diff --git a/crates/ra_tt/src/lib.rs b/crates/ra_tt/src/lib.rs
index 20c251ff4..10f424aae 100644
--- a/crates/ra_tt/src/lib.rs
+++ b/crates/ra_tt/src/lib.rs
@@ -33,14 +33,14 @@ impl TokenId {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum TokenTree {
     Leaf(Leaf),
     Subtree(Subtree),
 }
 impl_froms!(TokenTree: Leaf, Subtree);
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum Leaf {
     Literal(Literal),
     Punct(Punct),
@@ -48,38 +48,45 @@ pub enum Leaf {
 }
 impl_froms!(Leaf: Literal, Punct, Ident);
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
 pub struct Subtree {
-    pub delimiter: Delimiter,
+    pub delimiter: Option<Delimiter>,
     pub token_trees: Vec<TokenTree>,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum Delimiter {
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct Delimiter {
+    pub id: TokenId,
+    pub kind: DelimiterKind,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum DelimiterKind {
     Parenthesis,
     Brace,
     Bracket,
-    None,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Literal {
     pub text: SmolStr,
+    pub id: TokenId,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Punct {
     pub char: char,
     pub spacing: Spacing,
+    pub id: TokenId,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Spacing {
     Alone,
     Joint,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Ident {
     pub text: SmolStr,
     pub id: TokenId,
@@ -96,11 +103,11 @@ impl fmt::Display for TokenTree {
 
 impl fmt::Display for Subtree {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let (l, r) = match self.delimiter {
-            Delimiter::Parenthesis => ("(", ")"),
-            Delimiter::Brace => ("{", "}"),
-            Delimiter::Bracket => ("[", "]"),
-            Delimiter::None => ("", ""),
+        let (l, r) = match self.delimiter_kind() {
+            Some(DelimiterKind::Parenthesis) => ("(", ")"),
+            Some(DelimiterKind::Brace) => ("{", "}"),
+            Some(DelimiterKind::Bracket) => ("[", "]"),
+            None => ("", ""),
         };
         f.write_str(l)?;
         let mut needs_space = false;
@@ -164,6 +171,10 @@ impl Subtree {
 
         self.token_trees.len() + children_count
     }
+
+    pub fn delimiter_kind(&self) -> Option<DelimiterKind> {
+        self.delimiter.map(|it| it.kind)
+    }
 }
 
 pub mod buffer;
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 1244ea8cf..659f77b71 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -207,8 +207,8 @@ pub fn lines_match(expected: &str, actual: &str) -> bool {
     // Let's not deal with / vs \ (windows...)
     // First replace backslash-escaped backslashes with forward slashes
     // which can occur in, for example, JSON output
-    let expected = expected.replace("\\\\", "/").replace("\\", "/");
-    let mut actual: &str = &actual.replace("\\\\", "/").replace("\\", "/");
+    let expected = expected.replace(r"\\", "/").replace(r"\", "/");
+    let mut actual: &str = &actual.replace(r"\\", "/").replace(r"\", "/");
     for (i, part) in expected.split("[..]").enumerate() {
         match actual.find(part) {
             Some(j) => {
@@ -356,6 +356,17 @@ pub fn read_text(path: &Path) -> String {
         .replace("\r\n", "\n")
 }
 
+pub fn skip_slow_tests() -> bool {
+    let should_skip = std::env::var("CI").is_err() && std::env::var("RUN_SLOW_TESTS").is_err();
+    if should_skip {
+        eprintln!("ignoring slow test")
+    } else {
+        let path = project_dir().join("./target/.slow_tests_cookie");
+        fs::write(&path, ".").unwrap();
+    }
+    should_skip
+}
+
 const REWRITE: bool = false;
 
 fn assert_equal_text(expected: &str, actual: &str, path: &Path) {