Merge branch 'master' into keyword_completion

# Conflicts:
#	docs/user/generated_features.adoc

175 files changed, 7387 insertions, 3882 deletions

diff --git a/.gitignore b/.gitignore
index dab51647d..aef0fac33 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,5 @@ crates/*/target
 *.iml
 .vscode/settings.json
 *.html
+generated_assists.adoc
+generated_features.adoc
diff --git a/Cargo.lock b/Cargo.lock
index 9981a2e33..308e36836 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -113,8 +113,9 @@ checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
 [[package]]
 name = "chalk-derive"
-version = "0.10.1-dev"
-source = "git+https://github.com/rust-lang/chalk.git?rev=329b7f3fdd2431ed6f6778cde53f22374c7d094c#329b7f3fdd2431ed6f6778cde53f22374c7d094c"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9bd01eab87277d973183a1d2e56bace1c11f8242c52c20636fb7dddf343ac9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -124,8 +125,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-engine"
-version = "0.10.1-dev"
-source = "git+https://github.com/rust-lang/chalk.git?rev=329b7f3fdd2431ed6f6778cde53f22374c7d094c#329b7f3fdd2431ed6f6778cde53f22374c7d094c"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c7a637c3d17ed555aef16e16952a5d1e127bd55178cc30be22afeb92da90c7d"
 dependencies = [
  "chalk-derive",
  "chalk-ir",
@@ -134,8 +136,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-ir"
-version = "0.10.1-dev"
-source = "git+https://github.com/rust-lang/chalk.git?rev=329b7f3fdd2431ed6f6778cde53f22374c7d094c#329b7f3fdd2431ed6f6778cde53f22374c7d094c"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "595e5735ded16c3f3dc348f7b15bbb2521a0080b1863cac38ad5271589944670"
 dependencies = [
  "chalk-derive",
  "lazy_static",
@@ -143,8 +146,9 @@ dependencies = [
 
 [[package]]
 name = "chalk-solve"
-version = "0.10.1-dev"
-source = "git+https://github.com/rust-lang/chalk.git?rev=329b7f3fdd2431ed6f6778cde53f22374c7d094c#329b7f3fdd2431ed6f6778cde53f22374c7d094c"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d9d938139db425867a30cc0cfec0269406d8238d0571d829041eaa7a8455d11"
 dependencies = [
  "chalk-derive",
  "chalk-engine",
@@ -243,12 +247,13 @@ dependencies = [
 
 [[package]]
 name = "crossbeam-queue"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab6bffe714b6bb07e42f201352c34f51fefd355ace793f9e638ebd52d23f98d2"
+checksum = "774ba60a54c213d409d5353bda12d49cd68d14e45036a285234c8d6f91f92570"
 dependencies = [
  "cfg-if",
  "crossbeam-utils",
+ "maybe-uninit",
 ]
 
 [[package]]
@@ -462,18 +467,18 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "1.3.2"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "076f042c5b7b98f31d205f1249267e12a6518c1481e9dae9764af19b707d2292"
+checksum = "c398b2b113b55809ceb9ee3e753fcbac793f1956663f3c36549c1346015c2afe"
 dependencies = [
  "autocfg",
 ]
 
 [[package]]
 name = "inotify"
-version = "0.7.0"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24e40d6fd5d64e2082e0c796495c8ef5ad667a96d03e5aaa0becfd9d47bcbfb8"
+checksum = "4816c66d2c8ae673df83366c18341538f234a26d65a9ecea5c348b453ac1d02f"
 dependencies = [
  "bitflags",
  "inotify-sys",
@@ -561,9 +566,9 @@ dependencies = [
 
 [[package]]
 name = "jod-thread"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4022656272c3e564a7cdebcaaba6518d844b0d0c1836597196efb5bfeb98bb49"
+checksum = "8b23360e99b8717f20aaa4598f5a6541efbe30630039fbc7706cf954a87947ae"
 
 [[package]]
 name = "kernel32-sys"
@@ -809,9 +814,9 @@ dependencies = [
 
 [[package]]
 name = "paste"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d53181dcd37421c08d3b69f887784956674d09c3f9a47a04fece2b130a5b346b"
+checksum = "d508492eeb1e5c38ee696371bf7b9fc33c83d46a7d451606b96458fbbbdc2dec"
 dependencies = [
  "paste-impl",
  "proc-macro-hack",
@@ -819,9 +824,9 @@ dependencies = [
 
 [[package]]
 name = "paste-impl"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05ca490fa1c034a71412b4d1edcb904ec5a0981a4426c9eb2128c0fda7a68d17"
+checksum = "84f328a6a63192b333fce5fbb4be79db6758a4d518dfac6d54412f1492f72d32"
 dependencies = [
  "proc-macro-hack",
  "proc-macro2",
@@ -871,18 +876,18 @@ checksum = "7e0456befd48169b9f13ef0f0ad46d492cf9d2dbb918bcf38e01eed4ce3ec5e4"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1502d12e458c49a4c9cbff560d0fe0060c252bc29799ed94ca2ed4bb665a0101"
+checksum = "beae6331a816b1f65d04c45b078fd8e6c93e8071771f41b8163255bbd8d7c8fa"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.6"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54a21852a652ad6f610c9510194f398ff6f8692e334fd1145fed931f7fbe44ea"
+checksum = "aa563d17ecb180e500da1cfd2b028310ac758de548efdd203e18f283af693f37"
 dependencies = [
  "proc-macro2",
 ]
@@ -977,7 +982,10 @@ dependencies = [
  "anymap",
  "drop_bomb",
  "either",
+ "fst",
+ "indexmap",
  "insta",
+ "itertools",
  "log",
  "once_cell",
  "ra_arena",
@@ -1006,6 +1014,7 @@ dependencies = [
  "ra_prof",
  "ra_syntax",
  "ra_tt",
+ "rustc-hash",
  "test_utils",
 ]
 
@@ -1119,6 +1128,7 @@ dependencies = [
  "memmap",
  "ra_mbe",
  "ra_proc_macro",
+ "ra_toolchain",
  "ra_tt",
  "serde_derive",
  "test_utils",
@@ -1400,9 +1410,9 @@ checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
 [[package]]
 name = "ryu"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed3d612bc64430efeb3f7ee6ef26d590dce0c43249217bddc62112540c7941e1"
+checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
 [[package]]
 name = "salsa"
@@ -1511,9 +1521,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.53"
+version = "1.0.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "993948e75b189211a9b31a7528f950c6adc21f9720b6438ff80a7fa2f864cea2"
+checksum = "ec2c5d7e739bc07a3e73381a39d61fdb5f671c60c1df26a130690665803d8226"
 dependencies = [
  "itoa",
  "ryu",
@@ -1533,9 +1543,9 @@ dependencies = [
 
 [[package]]
 name = "serde_yaml"
-version = "0.8.12"
+version = "0.8.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16c7a592a1ec97c9c1c68d75b6e537dcbf60c7618e038e7841e00af1d9ccf0c4"
+checksum = "ae3e2dd40a7cdc18ca80db804b7f461a39bb721160a85c9a1fa30134bf3c02a5"
 dependencies = [
  "dtoa",
  "linked-hash-map",
@@ -1576,9 +1586,9 @@ checksum = "ab16ced94dbd8a46c82fd81e3ed9a8727dac2977ea869d217bcc4ea1f122e81f"
 
 [[package]]
 name = "syn"
-version = "1.0.29"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb37da98a55b1d08529362d9cbb863be17556873df2585904ab9d2bc951291d0"
+checksum = "b5304cfdf27365b7585c25d4af91b35016ed21ef88f17ced89c7093b43dba8b6"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1587,9 +1597,9 @@ dependencies = [
 
 [[package]]
 name = "synstructure"
-version = "0.12.3"
+version = "0.12.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67656ea1dc1b41b1451851562ea232ec2e5a80242139f7e679ceccfb5d61f545"
+checksum = "b834f2d66f734cb897113e34aaff2f1ab4719ca946f9a7358dba8f8064148701"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1639,6 +1649,7 @@ dependencies = [
  "relative-path",
  "rustc-hash",
  "serde_json",
+ "stdx",
  "text-size",
 ]
 
@@ -1797,9 +1808,9 @@ dependencies = [
 
 [[package]]
 name = "yaml-rust"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65923dd1784f44da1d2c3dbbc5e822045628c590ba72123e1c73d3c230c4434d"
+checksum = "39f0c922f1a334134dc2f7a8b67dc5d25f0735263feec974345ff706bcf20b0d"
 dependencies = [
  "linked-hash-map",
 ]
diff --git a/crates/ra_assists/src/assist_context.rs b/crates/ra_assists/src/assist_context.rs
index 5b1a4680b..edd8255f4 100644
--- a/crates/ra_assists/src/assist_context.rs
+++ b/crates/ra_assists/src/assist_context.rs
@@ -1,5 +1,7 @@
 //! See `AssistContext`
 
+use std::mem;
+
 use algo::find_covering_element;
 use hir::Semantics;
 use ra_db::{FileId, FileRange};
@@ -170,13 +172,32 @@ impl Assists {
 
 pub(crate) struct AssistBuilder {
     edit: TextEditBuilder,
-    file: FileId,
+    file_id: FileId,
     is_snippet: bool,
+    edits: Vec<SourceFileEdit>,
 }
 
 impl AssistBuilder {
-    pub(crate) fn new(file: FileId) -> AssistBuilder {
-        AssistBuilder { edit: TextEditBuilder::default(), file, is_snippet: false }
+    pub(crate) fn new(file_id: FileId) -> AssistBuilder {
+        AssistBuilder {
+            edit: TextEditBuilder::default(),
+            file_id,
+            is_snippet: false,
+            edits: Vec::new(),
+        }
+    }
+
+    pub(crate) fn edit_file(&mut self, file_id: FileId) {
+        self.file_id = file_id;
+    }
+
+    fn commit(&mut self) {
+        let edit = mem::take(&mut self.edit).finish();
+        if !edit.is_empty() {
+            let new_edit = SourceFileEdit { file_id: self.file_id, edit };
+            assert!(!self.edits.iter().any(|it| it.file_id == new_edit.file_id));
+            self.edits.push(new_edit);
+        }
     }
 
     /// Remove specified `range` of text.
@@ -234,21 +255,15 @@ impl AssistBuilder {
         algo::diff(&node, &new).into_text_edit(&mut self.edit)
     }
 
-    // FIXME: better API
-    pub(crate) fn set_file(&mut self, assist_file: FileId) {
-        self.file = assist_file;
-    }
-
     // FIXME: kill this API
     /// Get access to the raw `TextEditBuilder`.
     pub(crate) fn text_edit_builder(&mut self) -> &mut TextEditBuilder {
         &mut self.edit
     }
 
-    fn finish(self) -> SourceChange {
-        let edit = self.edit.finish();
-        let source_file_edit = SourceFileEdit { file_id: self.file, edit };
-        let mut res: SourceChange = source_file_edit.into();
+    fn finish(mut self) -> SourceChange {
+        self.commit();
+        let mut res: SourceChange = mem::take(&mut self.edits).into();
         if self.is_snippet {
             res.is_snippet = true;
         }
diff --git a/crates/ra_assists/src/handlers/add_explicit_type.rs b/crates/ra_assists/src/handlers/add_explicit_type.rs
index ab20c6649..90b06a625 100644
--- a/crates/ra_assists/src/handlers/add_explicit_type.rs
+++ b/crates/ra_assists/src/handlers/add_explicit_type.rs
@@ -195,7 +195,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test<|> = Test { t: 23, k: 33 };
+    let test<|> = Test { t: 23u8, k: 33 };
 }"#,
             r#"
 struct Test<K, T = u8> {
@@ -204,7 +204,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let test: Test<i32> = Test { t: 23, k: 33 };
+    let test: Test<i32> = Test { t: 23u8, k: 33 };
 }"#,
         );
     }
diff --git a/crates/ra_assists/src/handlers/add_function.rs b/crates/ra_assists/src/handlers/add_function.rs
index 24f931a85..1cfbd75aa 100644
--- a/crates/ra_assists/src/handlers/add_function.rs
+++ b/crates/ra_assists/src/handlers/add_function.rs
@@ -64,7 +64,7 @@ pub(crate) fn add_function(acc: &mut Assists, ctx: &AssistContext) -> Option<()>
     let target = call.syntax().text_range();
     acc.add(AssistId("add_function"), "Add function", target, |builder| {
         let function_template = function_builder.render();
-        builder.set_file(function_template.file);
+        builder.edit_file(function_template.file);
         let new_fn = function_template.to_string(ctx.config.snippet_cap);
         match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, function_template.insert_offset, new_fn),
diff --git a/crates/ra_assists/src/handlers/auto_import.rs b/crates/ra_assists/src/handlers/auto_import.rs
index edf96d50e..5092bf336 100644
--- a/crates/ra_assists/src/handlers/auto_import.rs
+++ b/crates/ra_assists/src/handlers/auto_import.rs
@@ -130,7 +130,7 @@ impl AutoImportAssets {
     fn search_for_imports(&self, db: &RootDatabase) -> BTreeSet<ModPath> {
         let _p = profile("auto_import::search_for_imports");
         let current_crate = self.module_with_name_to_import.krate();
-        ImportsLocator::new(db)
+        ImportsLocator::new(db, current_crate)
             .find_imports(&self.get_search_query())
             .into_iter()
             .filter_map(|candidate| match &self.import_candidate {
@@ -841,4 +841,105 @@ fn main() {
             ",
         )
     }
+
+    #[test]
+    fn dep_import() {
+        check_assist(
+            auto_import,
+            r"
+                    //- /lib.rs crate:dep
+                    pub struct Struct;
+
+                    //- /main.rs crate:main deps:dep
+                    fn main() {
+                        Struct<|>
+                    }",
+            r"use dep::Struct;
+
+fn main() {
+    Struct
+}
+",
+        );
+    }
+
+    #[test]
+    fn whole_segment() {
+        // Tests that only imports whose last segment matches the identifier get suggested.
+        check_assist(
+            auto_import,
+            r"
+                    //- /lib.rs crate:dep
+                    pub mod fmt {
+                        pub trait Display {}
+                    }
+
+                    pub fn panic_fmt() {}
+
+                    //- /main.rs crate:main deps:dep
+                    struct S;
+
+                    impl f<|>mt::Display for S {}",
+            r"use dep::fmt;
+
+struct S;
+impl fmt::Display for S {}
+",
+        );
+    }
+
+    #[test]
+    fn macro_generated() {
+        // Tests that macro-generated items are suggested from external crates.
+        check_assist(
+            auto_import,
+            r"
+                    //- /lib.rs crate:dep
+
+                    macro_rules! mac {
+                        () => {
+                            pub struct Cheese;
+                        };
+                    }
+
+                    mac!();
+
+                    //- /main.rs crate:main deps:dep
+
+                    fn main() {
+                        Cheese<|>;
+                    }",
+            r"use dep::Cheese;
+
+fn main() {
+    Cheese;
+}
+",
+        );
+    }
+
+    #[test]
+    fn casing() {
+        // Tests that differently cased names don't interfere and we only suggest the matching one.
+        check_assist(
+            auto_import,
+            r"
+                    //- /lib.rs crate:dep
+
+                    pub struct FMT;
+                    pub struct fmt;
+
+                    //- /main.rs crate:main deps:dep
+
+                    fn main() {
+                        FMT<|>;
+                    }",
+            r"use dep::FMT;
+
+fn main() {
+    FMT;
+}
+",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/handlers/early_return.rs b/crates/ra_assists/src/handlers/early_return.rs
index 4cc75a7ce..dfade7432 100644
--- a/crates/ra_assists/src/handlers/early_return.rs
+++ b/crates/ra_assists/src/handlers/early_return.rs
@@ -154,7 +154,7 @@ pub(crate) fn convert_to_guarded_return(acc: &mut Assists, ctx: &AssistContext)
             parent_block: &ast::BlockExpr,
             if_expr: &ast::IfExpr,
         ) -> SyntaxNode {
-            let then_block_items = then_block.dedent(IndentLevel::from(1));
+            let then_block_items = then_block.dedent(IndentLevel(1));
             let end_of_then = then_block_items.syntax().last_child_or_token().unwrap();
             let end_of_then =
                 if end_of_then.prev_sibling_or_token().map(|n| n.kind()) == Some(WHITESPACE) {
diff --git a/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
new file mode 100644
index 000000000..44db7917a
--- /dev/null
+++ b/crates/ra_assists/src/handlers/extract_struct_from_enum_variant.rs
@@ -0,0 +1,320 @@
+use hir::{EnumVariant, Module, ModuleDef, Name};
+use ra_db::FileId;
+use ra_fmt::leading_indent;
+use ra_ide_db::{defs::Definition, search::Reference, RootDatabase};
+use ra_syntax::{
+    algo::find_node_at_offset,
+    ast::{self, ArgListOwner, AstNode, NameOwner, VisibilityOwner},
+    SourceFile, SyntaxNode, TextRange, TextSize,
+};
+use rustc_hash::FxHashSet;
+
+use crate::{
+    assist_context::AssistBuilder, utils::insert_use_statement, AssistContext, AssistId, Assists,
+};
+
+// Assist: extract_struct_from_enum_variant
+//
+// Extracts a struct from enum variant.
+//
+// ```
+// enum A { <|>One(u32, u32) }
+// ```
+// ->
+// ```
+// struct One(pub u32, pub u32);
+//
+// enum A { One(One) }
+// ```
+pub(crate) fn extract_struct_from_enum_variant(
+    acc: &mut Assists,
+    ctx: &AssistContext,
+) -> Option<()> {
+    let variant = ctx.find_node_at_offset::<ast::EnumVariant>()?;
+    let field_list = match variant.kind() {
+        ast::StructKind::Tuple(field_list) => field_list,
+        _ => return None,
+    };
+    let variant_name = variant.name()?.to_string();
+    let variant_hir = ctx.sema.to_def(&variant)?;
+    if existing_struct_def(ctx.db, &variant_name, &variant_hir) {
+        return None;
+    }
+    let enum_ast = variant.parent_enum();
+    let visibility = enum_ast.visibility();
+    let enum_hir = ctx.sema.to_def(&enum_ast)?;
+    let variant_hir_name = variant_hir.name(ctx.db);
+    let enum_module_def = ModuleDef::from(enum_hir);
+    let current_module = enum_hir.module(ctx.db);
+    let target = variant.syntax().text_range();
+    acc.add(
+        AssistId("extract_struct_from_enum_variant"),
+        "Extract struct from enum variant",
+        target,
+        |builder| {
+            let definition = Definition::ModuleDef(ModuleDef::EnumVariant(variant_hir));
+            let res = definition.find_usages(&ctx.db, None);
+            let start_offset = variant.parent_enum().syntax().text_range().start();
+            let mut visited_modules_set = FxHashSet::default();
+            visited_modules_set.insert(current_module);
+            for reference in res {
+                let source_file = ctx.sema.parse(reference.file_range.file_id);
+                update_reference(
+                    ctx,
+                    builder,
+                    reference,
+                    &source_file,
+                    &enum_module_def,
+                    &variant_hir_name,
+                    &mut visited_modules_set,
+                );
+            }
+            extract_struct_def(
+                builder,
+                enum_ast.syntax(),
+                &variant_name,
+                &field_list.to_string(),
+                start_offset,
+                ctx.frange.file_id,
+                &visibility,
+            );
+            let list_range = field_list.syntax().text_range();
+            update_variant(builder, &variant_name, ctx.frange.file_id, list_range);
+        },
+    )
+}
+
+fn existing_struct_def(db: &RootDatabase, variant_name: &str, variant: &EnumVariant) -> bool {
+    variant
+        .parent_enum(db)
+        .module(db)
+        .scope(db, None)
+        .into_iter()
+        .any(|(name, _)| name.to_string() == variant_name.to_string())
+}
+
+fn insert_import(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    path: &ast::PathExpr,
+    module: &Module,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+) -> Option<()> {
+    let db = ctx.db;
+    let mod_path = module.find_use_path(db, enum_module_def.clone());
+    if let Some(mut mod_path) = mod_path {
+        mod_path.segments.pop();
+        mod_path.segments.push(variant_hir_name.clone());
+        insert_use_statement(path.syntax(), &mod_path, ctx, builder.text_edit_builder());
+    }
+    Some(())
+}
+
+fn extract_struct_def(
+    builder: &mut AssistBuilder,
+    enum_ast: &SyntaxNode,
+    variant_name: &str,
+    variant_list: &str,
+    start_offset: TextSize,
+    file_id: FileId,
+    visibility: &Option<ast::Visibility>,
+) -> Option<()> {
+    let visibility_string = if let Some(visibility) = visibility {
+        format!("{} ", visibility.to_string())
+    } else {
+        "".to_string()
+    };
+    let indent = if let Some(indent) = leading_indent(enum_ast) {
+        indent.to_string()
+    } else {
+        "".to_string()
+    };
+    let struct_def = format!(
+        r#"{}struct {}{};
+
+{}"#,
+        visibility_string,
+        variant_name,
+        list_with_visibility(variant_list),
+        indent
+    );
+    builder.edit_file(file_id);
+    builder.insert(start_offset, struct_def);
+    Some(())
+}
+
+fn update_variant(
+    builder: &mut AssistBuilder,
+    variant_name: &str,
+    file_id: FileId,
+    list_range: TextRange,
+) -> Option<()> {
+    let inside_variant_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(file_id);
+    builder.replace(inside_variant_range, variant_name);
+    Some(())
+}
+
+fn update_reference(
+    ctx: &AssistContext,
+    builder: &mut AssistBuilder,
+    reference: Reference,
+    source_file: &SourceFile,
+    enum_module_def: &ModuleDef,
+    variant_hir_name: &Name,
+    visited_modules_set: &mut FxHashSet<Module>,
+) -> Option<()> {
+    let path_expr: ast::PathExpr = find_node_at_offset::<ast::PathExpr>(
+        source_file.syntax(),
+        reference.file_range.range.start(),
+    )?;
+    let call = path_expr.syntax().parent().and_then(ast::CallExpr::cast)?;
+    let list = call.arg_list()?;
+    let segment = path_expr.path()?.segment()?;
+    let module = ctx.sema.scope(&path_expr.syntax()).module()?;
+    let list_range = list.syntax().text_range();
+    let inside_list_range = TextRange::new(
+        list_range.start().checked_add(TextSize::from(1))?,
+        list_range.end().checked_sub(TextSize::from(1))?,
+    );
+    builder.edit_file(reference.file_range.file_id);
+    if !visited_modules_set.contains(&module) {
+        if insert_import(ctx, builder, &path_expr, &module, enum_module_def, variant_hir_name)
+            .is_some()
+        {
+            visited_modules_set.insert(module);
+        }
+    }
+    builder.replace(inside_list_range, format!("{}{}", segment, list));
+    Some(())
+}
+
+fn list_with_visibility(list: &str) -> String {
+    list.split(',')
+        .map(|part| {
+            let index = if part.chars().next().unwrap() == '(' { 1usize } else { 0 };
+            let mut mod_part = part.trim().to_string();
+            mod_part.insert_str(index, "pub ");
+            mod_part
+        })
+        .collect::<Vec<String>>()
+        .join(", ")
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::{
+        tests::{check_assist, check_assist_not_applicable},
+        utils::FamousDefs,
+    };
+
+    use super::*;
+
+    #[test]
+    fn test_extract_struct_several_fields() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32, u32) }",
+            r#"struct One(pub u32, pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_one_field() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "enum A { <|>One(u32) }",
+            r#"struct One(pub u32);
+
+enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_pub_visibility() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            "pub enum A { <|>One(u32, u32) }",
+            r#"pub struct One(pub u32, pub u32);
+
+pub enum A { One(One) }"#,
+        );
+    }
+
+    #[test]
+    fn test_extract_struct_with_complex_imports() {
+        check_assist(
+            extract_struct_from_enum_variant,
+            r#"mod my_mod {
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(1, 1);
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(1, 1);
+        }
+
+        pub enum MyEnum {
+            <|>MyField(u8, u8),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(1, 1);
+}"#,
+            r#"use my_mod::my_other_mod::MyField;
+
+mod my_mod {
+    use my_other_mod::MyField;
+
+    fn another_fn() {
+        let m = my_other_mod::MyEnum::MyField(MyField(1, 1));
+    }
+
+    pub mod my_other_mod {
+        fn another_fn() {
+            let m = MyEnum::MyField(MyField(1, 1));
+        }
+
+        pub struct MyField(pub u8, pub u8);
+
+        pub enum MyEnum {
+            MyField(MyField),
+        }
+    }
+}
+
+fn another_fn() {
+    let m = my_mod::my_other_mod::MyEnum::MyField(MyField(1, 1));
+}"#,
+        );
+    }
+
+    fn check_not_applicable(ra_fixture: &str) {
+        let fixture =
+            format!("//- main.rs crate:main deps:core\n{}\n{}", ra_fixture, FamousDefs::FIXTURE);
+        check_assist_not_applicable(extract_struct_from_enum_variant, &fixture)
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_for_element_with_no_fields() {
+        check_not_applicable("enum A { <|>One }");
+    }
+
+    #[test]
+    fn test_extract_enum_not_applicable_if_struct_exists() {
+        check_not_applicable(
+            r#"struct One;
+        enum A { <|>One(u8) }"#,
+        );
+    }
+}
diff --git a/crates/ra_assists/src/handlers/fix_visibility.rs b/crates/ra_assists/src/handlers/fix_visibility.rs
index 9ec42f568..531b3560f 100644
--- a/crates/ra_assists/src/handlers/fix_visibility.rs
+++ b/crates/ra_assists/src/handlers/fix_visibility.rs
@@ -63,7 +63,7 @@ fn add_vis_to_referenced_module_def(acc: &mut Assists, ctx: &AssistContext) -> O
     };
 
     acc.add(AssistId("fix_visibility"), assist_label, target, |builder| {
-        builder.set_file(target_file);
+        builder.edit_file(target_file);
         match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, offset, format!("$0{} ", missing_visibility)),
             None => builder.insert(offset, format!("{} ", missing_visibility)),
@@ -106,7 +106,7 @@ fn add_vis_to_referenced_record_field(acc: &mut Assists, ctx: &AssistContext) ->
         format!("Change visibility of {}.{} to {}", parent_name, target_name, missing_visibility);
 
     acc.add(AssistId("fix_visibility"), assist_label, target, |builder| {
-        builder.set_file(target_file);
+        builder.edit_file(target_file);
         match ctx.config.snippet_cap {
             Some(cap) => builder.insert_snippet(cap, offset, format!("$0{} ", missing_visibility)),
             None => builder.insert(offset, format!("{} ", missing_visibility)),
diff --git a/crates/ra_assists/src/handlers/introduce_named_lifetime.rs b/crates/ra_assists/src/handlers/introduce_named_lifetime.rs
index beb5b7366..28fcbc9ba 100644
--- a/crates/ra_assists/src/handlers/introduce_named_lifetime.rs
+++ b/crates/ra_assists/src/handlers/introduce_named_lifetime.rs
@@ -41,8 +41,6 @@ pub(crate) fn introduce_named_lifetime(acc: &mut Assists, ctx: &AssistContext) -
     if let Some(fn_def) = lifetime_token.ancestors().find_map(ast::FnDef::cast) {
         generate_fn_def_assist(acc, &fn_def, lifetime_token.text_range())
     } else if let Some(impl_def) = lifetime_token.ancestors().find_map(ast::ImplDef::cast) {
-        // only allow naming the last anonymous lifetime
-        lifetime_token.next_token().filter(|tok| tok.kind() == SyntaxKind::R_ANGLE)?;
         generate_impl_def_assist(acc, &impl_def, lifetime_token.text_range())
     } else {
         None
@@ -191,6 +189,23 @@ mod tests {
     }
 
     #[test]
+    fn test_impl_with_other_type_param() {
+        check_assist(
+            introduce_named_lifetime,
+            "impl<I> fmt::Display for SepByBuilder<'_<|>, I>
+        where
+            I: Iterator,
+            I::Item: fmt::Display,
+        {",
+            "impl<I, 'a> fmt::Display for SepByBuilder<'a, I>
+        where
+            I: Iterator,
+            I::Item: fmt::Display,
+        {",
+        )
+    }
+
+    #[test]
     fn test_example_case_cursor_before_tick() {
         check_assist(
             introduce_named_lifetime,
diff --git a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
index e016f51c3..dfcd787de 100644
--- a/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/handlers/replace_if_let_with_match.rs
@@ -51,6 +51,7 @@ pub(crate) fn replace_if_let_with_match(acc: &mut Assists, ctx: &AssistContext)
     acc.add(AssistId("replace_if_let_with_match"), "Replace with match", target, move |edit| {
         let match_expr = {
             let then_arm = {
+                let then_block = then_block.reset_indent().indent(IndentLevel(1));
                 let then_expr = unwrap_trivial_block(then_block);
                 make::match_arm(vec![pat.clone()], then_expr)
             };
@@ -64,8 +65,8 @@ pub(crate) fn replace_if_let_with_match(acc: &mut Assists, ctx: &AssistContext)
                 let else_expr = unwrap_trivial_block(else_block);
                 make::match_arm(vec![pattern], else_expr)
             };
-            make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]))
-                .indent(IndentLevel::from_node(if_expr.syntax()))
+            let match_expr = make::expr_match(expr, make::match_arm_list(vec![then_arm, else_arm]));
+            match_expr.indent(IndentLevel::from_node(if_expr.syntax()))
         };
 
         edit.replace_ast::<ast::Expr>(if_expr.into(), match_expr);
@@ -213,4 +214,36 @@ fn foo(x: Result<i32, ()>) {
            "#,
         );
     }
+
+    #[test]
+    fn nested_indent() {
+        check_assist(
+            replace_if_let_with_match,
+            r#"
+fn main() {
+    if true {
+        <|>if let Ok(rel_path) = path.strip_prefix(root_path) {
+            let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+            Some((*id, rel_path))
+        } else {
+            None
+        }
+    }
+}
+"#,
+            r#"
+fn main() {
+    if true {
+        match path.strip_prefix(root_path) {
+            Ok(rel_path) => {
+                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+                Some((*id, rel_path))
+            }
+            _ => None,
+        }
+    }
+}
+"#,
+        )
+    }
 }
diff --git a/crates/ra_assists/src/handlers/unwrap_block.rs b/crates/ra_assists/src/handlers/unwrap_block.rs
index 8440c7d0f..1fb13f481 100644
--- a/crates/ra_assists/src/handlers/unwrap_block.rs
+++ b/crates/ra_assists/src/handlers/unwrap_block.rs
@@ -1,7 +1,10 @@
 use ra_fmt::unwrap_trivial_block;
 use ra_syntax::{
-    ast::{self, ElseBranch, Expr, LoopBodyOwner},
-    match_ast, AstNode, TextRange, T,
+    ast::{
+        self,
+        edit::{AstNodeEdit, IndentLevel},
+    },
+    AstNode, TextRange, T,
 };
 
 use crate::{AssistContext, AssistId, Assists};
@@ -24,94 +27,73 @@ use crate::{AssistContext, AssistId, Assists};
 // }
 // ```
 pub(crate) fn unwrap_block(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
-    let l_curly_token = ctx.find_token_at_offset(T!['{'])?;
-    let block = ast::BlockExpr::cast(l_curly_token.parent())?;
-    let parent = block.syntax().parent()?;
     let assist_id = AssistId("unwrap_block");
     let assist_label = "Unwrap block";
 
-    let (expr, expr_to_unwrap) = match_ast! {
-        match parent {
-            ast::ForExpr(for_expr) => {
-                let block_expr = for_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::ForExpr(for_expr), expr_to_unwrap)
-            },
-            ast::WhileExpr(while_expr) => {
-                let block_expr = while_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::WhileExpr(while_expr), expr_to_unwrap)
-            },
-            ast::LoopExpr(loop_expr) => {
-                let block_expr = loop_expr.loop_body()?;
-                let expr_to_unwrap = extract_expr(ctx.frange.range, block_expr)?;
-                (ast::Expr::LoopExpr(loop_expr), expr_to_unwrap)
-            },
-            ast::IfExpr(if_expr) => {
-                let mut resp = None;
-
-                let then_branch = if_expr.then_branch()?;
-                if then_branch.l_curly_token()?.text_range().contains_range(ctx.frange.range) {
-                    if let Some(ancestor) = if_expr.syntax().parent().and_then(ast::IfExpr::cast) {
-                        // For `else if` blocks
-                        let ancestor_then_branch = ancestor.then_branch()?;
-                        let l_curly_token = then_branch.l_curly_token()?;
-
-                        let target = then_branch.syntax().text_range();
-                        return acc.add(assist_id, assist_label, target, |edit| {
-                            let range_to_del_else_if = TextRange::new(ancestor_then_branch.syntax().text_range().end(), l_curly_token.text_range().start());
-                            let range_to_del_rest = TextRange::new(then_branch.syntax().text_range().end(), if_expr.syntax().text_range().end());
-
-                            edit.delete(range_to_del_rest);
-                            edit.delete(range_to_del_else_if);
-                            edit.replace(target, update_expr_string(then_branch.to_string(), &[' ', '{']));
-                        });
-                    } else {
-                        resp = Some((ast::Expr::IfExpr(if_expr.clone()), Expr::BlockExpr(then_branch)));
-                    }
-                } else if let Some(else_branch) = if_expr.else_branch() {
-                    match else_branch {
-                        ElseBranch::Block(else_block) => {
-                            let l_curly_token = else_block.l_curly_token()?;
-                            if l_curly_token.text_range().contains_range(ctx.frange.range) {
-                                let target = else_block.syntax().text_range();
-                                return acc.add(assist_id, assist_label, target, |edit| {
-                                    let range_to_del = TextRange::new(then_branch.syntax().text_range().end(), l_curly_token.text_range().start());
-
-                                    edit.delete(range_to_del);
-                                    edit.replace(target, update_expr_string(else_block.to_string(), &[' ', '{']));
-                                });
-                            }
-                        },
-                        ElseBranch::IfExpr(_) => {},
-                    }
-                }
+    let l_curly_token = ctx.find_token_at_offset(T!['{'])?;
+    let mut block = ast::BlockExpr::cast(l_curly_token.parent())?;
+    let mut parent = block.syntax().parent()?;
+    if ast::MatchArm::can_cast(parent.kind()) {
+        parent = parent.ancestors().find(|it| ast::MatchExpr::can_cast(it.kind()))?
+    }
 
-                resp?
-            },
-            _ => return None,
+    let parent = ast::Expr::cast(parent)?;
+
+    match parent.clone() {
+        ast::Expr::ForExpr(_) | ast::Expr::WhileExpr(_) | ast::Expr::LoopExpr(_) => (),
+        ast::Expr::MatchExpr(_) => block = block.dedent(IndentLevel(1)),
+        ast::Expr::IfExpr(if_expr) => {
+            let then_branch = if_expr.then_branch()?;
+            if then_branch == block {
+                if let Some(ancestor) = if_expr.syntax().parent().and_then(ast::IfExpr::cast) {
+                    // For `else if` blocks
+                    let ancestor_then_branch = ancestor.then_branch()?;
+
+                    let target = then_branch.syntax().text_range();
+                    return acc.add(assist_id, assist_label, target, |edit| {
+                        let range_to_del_else_if = TextRange::new(
+                            ancestor_then_branch.syntax().text_range().end(),
+                            l_curly_token.text_range().start(),
+                        );
+                        let range_to_del_rest = TextRange::new(
+                            then_branch.syntax().text_range().end(),
+                            if_expr.syntax().text_range().end(),
+                        );
+
+                        edit.delete(range_to_del_rest);
+                        edit.delete(range_to_del_else_if);
+                        edit.replace(
+                            target,
+                            update_expr_string(then_branch.to_string(), &[' ', '{']),
+                        );
+                    });
+                }
+            } else {
+                let target = block.syntax().text_range();
+                return acc.add(assist_id, assist_label, target, |edit| {
+                    let range_to_del = TextRange::new(
+                        then_branch.syntax().text_range().end(),
+                        l_curly_token.text_range().start(),
+                    );
+
+                    edit.delete(range_to_del);
+                    edit.replace(target, update_expr_string(block.to_string(), &[' ', '{']));
+                });
+            }
         }
+        _ => return None,
     };
 
-    let target = expr_to_unwrap.syntax().text_range();
-    acc.add(assist_id, assist_label, target, |edit| {
-        edit.replace(
-            expr.syntax().text_range(),
-            update_expr_string(expr_to_unwrap.to_string(), &[' ', '{', '\n']),
+    let unwrapped = unwrap_trivial_block(block);
+    let target = unwrapped.syntax().text_range();
+    acc.add(assist_id, assist_label, target, |builder| {
+        builder.replace(
+            parent.syntax().text_range(),
+            update_expr_string(unwrapped.to_string(), &[' ', '{', '\n']),
         );
     })
 }
 
-fn extract_expr(cursor_range: TextRange, block: ast::BlockExpr) -> Option<ast::Expr> {
-    let cursor_in_range = block.l_curly_token()?.text_range().contains_range(cursor_range);
-
-    if cursor_in_range {
-        Some(unwrap_trivial_block(block))
-    } else {
-        None
-    }
-}
-
 fn update_expr_string(expr_str: String, trim_start_pat: &[char]) -> String {
     let expr_string = expr_str.trim_start_matches(trim_start_pat);
     let mut expr_string_lines: Vec<&str> = expr_string.lines().collect();
@@ -490,6 +472,30 @@ mod tests {
     }
 
     #[test]
+    fn unwrap_match_arm() {
+        check_assist(
+            unwrap_block,
+            r#"
+fn main() {
+    match rel_path {
+        Ok(rel_path) => {<|>
+            let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+            Some((*id, rel_path))
+        }
+        Err(_) => None,
+    }
+}
+"#,
+            r#"
+fn main() {
+    let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+    Some((*id, rel_path))
+}
+"#,
+        );
+    }
+
+    #[test]
     fn simple_if_in_while_bad_cursor_position() {
         check_assist_not_applicable(
             unwrap_block,
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index fb5d59a87..185428bd5 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -115,6 +115,7 @@ mod handlers {
     mod change_return_type_to_result;
     mod change_visibility;
     mod early_return;
+    mod extract_struct_from_enum_variant;
     mod fill_match_arms;
     mod fix_visibility;
     mod flip_binexpr;
@@ -155,6 +156,7 @@ mod handlers {
             change_return_type_to_result::change_return_type_to_result,
             change_visibility::change_visibility,
             early_return::convert_to_guarded_return,
+            extract_struct_from_enum_variant::extract_struct_from_enum_variant,
             fill_match_arms::fill_match_arms,
             fix_visibility::fix_visibility,
             flip_binexpr::flip_binexpr,
diff --git a/crates/ra_assists/src/tests/generated.rs b/crates/ra_assists/src/tests/generated.rs
index d17504529..40a223727 100644
--- a/crates/ra_assists/src/tests/generated.rs
+++ b/crates/ra_assists/src/tests/generated.rs
@@ -338,6 +338,21 @@ fn main() {
 }
 
 #[test]
+fn doctest_extract_struct_from_enum_variant() {
+    check_doc_test(
+        "extract_struct_from_enum_variant",
+        r#####"
+enum A { <|>One(u32, u32) }
+"#####,
+        r#####"
+struct One(pub u32, pub u32);
+
+enum A { One(One) }
+"#####,
+    )
+}
+
+#[test]
 fn doctest_fill_match_arms() {
     check_doc_test(
         "fill_match_arms",
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index 4d2d3b48a..bf26048f2 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -15,12 +15,10 @@ use std::{
 
 use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
-use rustc_hash::FxHashMap;
-use rustc_hash::FxHashSet;
+use ra_tt::TokenExpander;
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{RelativePath, RelativePathBuf};
-use fmt::Display;
-use ra_tt::TokenExpander;
 
 /// `FileId` is an integer which uniquely identifies a file. File paths are
 /// messy and system-dependent, so most of the code should work directly with
@@ -111,7 +109,7 @@ impl CrateName {
     }
 }
 
-impl Display for CrateName {
+impl fmt::Display for CrateName {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", self.0)
     }
@@ -337,15 +335,11 @@ impl Env {
 }
 
 impl ExternSource {
-    pub fn extern_path(&self, path: impl AsRef<Path>) -> Option<(ExternSourceId, RelativePathBuf)> {
-        let path = path.as_ref();
+    pub fn extern_path(&self, path: &Path) -> Option<(ExternSourceId, RelativePathBuf)> {
         self.extern_paths.iter().find_map(|(root_path, id)| {
-            if let Ok(rel_path) = path.strip_prefix(root_path) {
-                let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
-                Some((*id, rel_path))
-            } else {
-                None
-            }
+            let rel_path = path.strip_prefix(root_path).ok()?;
+            let rel_path = RelativePathBuf::from_path(rel_path).ok()?;
+            Some((*id, rel_path))
         })
     }
 
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index fd4280de2..80ddb6058 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -7,12 +7,13 @@ use std::{panic, sync::Arc};
 
 use ra_prof::profile;
 use ra_syntax::{ast, Parse, SourceFile, TextRange, TextSize};
+use rustc_hash::FxHashSet;
 
 pub use crate::{
     cancellation::Canceled,
     input::{
-        CrateGraph, CrateId, CrateName, Dependency, Edition, Env, ExternSource, ExternSourceId,
-        FileId, ProcMacroId, SourceRoot, SourceRootId,
+        CrateData, CrateGraph, CrateId, CrateName, Dependency, Edition, Env, ExternSource,
+        ExternSourceId, FileId, ProcMacroId, SourceRoot, SourceRootId,
     },
 };
 pub use relative_path::{RelativePath, RelativePathBuf};
@@ -89,15 +90,13 @@ pub const DEFAULT_LRU_CAP: usize = 128;
 pub trait FileLoader {
     /// Text of the file.
     fn file_text(&self, file_id: FileId) -> Arc<String>;
-    fn resolve_relative_path(&self, anchor: FileId, relative_path: &RelativePath)
-        -> Option<FileId>;
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>>;
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId>;
+    /// Note that we intentionally accept a `&str` and not a `&Path` here. This
+    /// method exists to handle `#[path = "/some/path.rs"] mod foo;` and such,
+    /// so the input is guaranteed to be utf-8 string. We might introduce
+    /// `struct StrPath(str)` for clarity some day, but it's a bit messy, so we
+    /// get by with a `&str` for the time being.
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId>;
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>>;
 }
 
 /// Database which stores all significant input facts: source code and project
@@ -135,16 +134,21 @@ pub trait SourceDatabaseExt: SourceDatabase {
     #[salsa::input]
     fn source_root(&self, id: SourceRootId) -> Arc<SourceRoot>;
 
-    fn source_root_crates(&self, id: SourceRootId) -> Arc<Vec<CrateId>>;
+    fn source_root_crates(&self, id: SourceRootId) -> Arc<FxHashSet<CrateId>>;
 }
 
 fn source_root_crates(
     db: &(impl SourceDatabaseExt + SourceDatabase),
     id: SourceRootId,
-) -> Arc<Vec<CrateId>> {
-    let root = db.source_root(id);
+) -> Arc<FxHashSet<CrateId>> {
     let graph = db.crate_graph();
-    let res = root.walk().filter_map(|it| graph.crate_id_for_crate_root(it)).collect::<Vec<_>>();
+    let res = graph
+        .iter()
+        .filter(|&krate| {
+            let root_file = graph[krate].root_file_id;
+            db.file_source_root(root_file) == id
+        })
+        .collect::<FxHashSet<_>>();
     Arc::new(res)
 }
 
@@ -155,33 +159,30 @@ impl<T: SourceDatabaseExt> FileLoader for FileLoaderDelegate<&'_ T> {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         SourceDatabaseExt::file_text(self.0, file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        let path = {
-            let mut path = self.0.file_relative_path(anchor);
-            assert!(path.pop());
-            path.push(relative_path);
-            path.normalize()
-        };
-        let source_root = self.0.file_source_root(anchor);
-        let source_root = self.0.source_root(source_root);
-        source_root.file_by_relative_path(&path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        // FIXME: this *somehow* should be platform agnostic...
+        if std::path::Path::new(path).is_absolute() {
+            let krate = *self.relevant_crates(anchor).iter().next()?;
+            let (extern_source_id, relative_file) =
+                self.0.crate_graph()[krate].extern_source.extern_path(path.as_ref())?;
+
+            let source_root = self.0.source_root(SourceRootId(extern_source_id.0));
+            source_root.file_by_relative_path(&relative_file)
+        } else {
+            let rel_path = {
+                let mut rel_path = self.0.file_relative_path(anchor);
+                assert!(rel_path.pop());
+                rel_path.push(path);
+                rel_path.normalize()
+            };
+            let source_root = self.0.file_source_root(anchor);
+            let source_root = self.0.source_root(source_root);
+            source_root.file_by_relative_path(&rel_path)
+        }
     }
 
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         let source_root = self.0.file_source_root(file_id);
         self.0.source_root_crates(source_root)
     }
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        let source_root = self.0.source_root(SourceRootId(extern_id.0));
-        source_root.file_by_relative_path(&relative_path)
-    }
 }
diff --git a/crates/ra_flycheck/src/lib.rs b/crates/ra_flycheck/src/lib.rs
index 041e38a9f..6c4170529 100644
--- a/crates/ra_flycheck/src/lib.rs
+++ b/crates/ra_flycheck/src/lib.rs
@@ -18,8 +18,17 @@ pub use cargo_metadata::diagnostic::{
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum FlycheckConfig {
-    CargoCommand { command: String, all_targets: bool, all_features: bool, extra_args: Vec<String> },
-    CustomCommand { command: String, args: Vec<String> },
+    CargoCommand {
+        command: String,
+        all_targets: bool,
+        all_features: bool,
+        features: Vec<String>,
+        extra_args: Vec<String>,
+    },
+    CustomCommand {
+        command: String,
+        args: Vec<String>,
+    },
 }
 
 /// Flycheck wraps the shared state and communication machinery used for
@@ -188,7 +197,13 @@ impl FlycheckThread {
         self.check_process = None;
 
         let mut cmd = match &self.config {
-            FlycheckConfig::CargoCommand { command, all_targets, all_features, extra_args } => {
+            FlycheckConfig::CargoCommand {
+                command,
+                all_targets,
+                all_features,
+                extra_args,
+                features,
+            } => {
                 let mut cmd = Command::new(ra_toolchain::cargo());
                 cmd.arg(command);
                 cmd.args(&["--workspace", "--message-format=json", "--manifest-path"])
@@ -198,6 +213,9 @@ impl FlycheckThread {
                 }
                 if *all_features {
                     cmd.arg("--all-features");
+                } else if !features.is_empty() {
+                    cmd.arg("--features");
+                    cmd.arg(features.join(" "));
                 }
                 cmd.args(extra_args);
                 cmd
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index e40aeffbc..1a9f6cc76 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -9,6 +9,7 @@ use hir_def::{
     builtin_type::BuiltinType,
     docs::Documentation,
     expr::{BindingAnnotation, Pat, PatId},
+    import_map,
     per_ns::PerNs,
     resolver::{HasResolver, Resolver},
     type_ref::{Mutability, TypeRef},
@@ -98,6 +99,23 @@ impl Crate {
         db.crate_graph()[self.id].display_name.as_ref().cloned()
     }
 
+    pub fn query_external_importables(
+        self,
+        db: &dyn DefDatabase,
+        query: &str,
+    ) -> impl Iterator<Item = Either<ModuleDef, MacroDef>> {
+        import_map::search_dependencies(
+            db,
+            self.into(),
+            import_map::Query::new(query).anchor_end().case_sensitive().limit(40),
+        )
+        .into_iter()
+        .map(|item| match item {
+            ItemInNs::Types(mod_id) | ItemInNs::Values(mod_id) => Either::Left(mod_id.into()),
+            ItemInNs::Macros(mac_id) => Either::Right(mac_id.into()),
+        })
+    }
+
     pub fn all(db: &dyn HirDatabase) -> Vec<Crate> {
         db.crate_graph().iter().map(|id| Crate { id }).collect()
     }
@@ -637,6 +655,10 @@ impl Function {
         db.function_data(self.id).params.clone()
     }
 
+    pub fn is_unsafe(self, db: &dyn HirDatabase) -> bool {
+        db.function_data(self.id).is_unsafe
+    }
+
     pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
         let _p = profile("Function::diagnostics");
         let infer = db.infer(self.id.into());
@@ -1190,6 +1212,10 @@ impl Type {
         )
     }
 
+    pub fn is_raw_ptr(&self) -> bool {
+        matches!(&self.ty.value, Ty::Apply(ApplicationTy { ctor: TypeCtor::RawPtr(..), .. }))
+    }
+
     pub fn contains_unknown(&self) -> bool {
         return go(&self.ty.value);
 
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index ec931b34f..b6b665de1 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -3,11 +3,11 @@
 pub use hir_def::db::{
     AttrsQuery, BodyQuery, BodyWithSourceMapQuery, ConstDataQuery, CrateDefMapQueryQuery,
     CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery,
-    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternConstQuery,
-    InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery, InternImplQuery,
-    InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery, InternUnionQuery,
-    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery, StructDataQuery,
-    TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
+    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, ImportMapQuery,
+    InternConstQuery, InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery,
+    InternImplQuery, InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery,
+    InternUnionQuery, LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery,
+    StructDataQuery, TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
     AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternEagerExpansionQuery, InternMacroQuery,
@@ -18,8 +18,8 @@ pub use hir_ty::db::{
     GenericDefaultsQuery, GenericPredicatesForParamQuery, GenericPredicatesQuery, HirDatabase,
     HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery, ImplsForTraitQuery,
     ImplsInCrateQuery, InferQueryQuery, InternAssocTyValueQuery, InternChalkImplQuery,
-    InternTypeCtorQuery, InternTypeParamIdQuery, StructDatumQuery, TraitDatumQuery,
-    TraitSolveQuery, TyQuery, ValueTyQuery,
+    InternTypeCtorQuery, InternTypeParamIdQuery, ReturnTypeImplTraitsQuery, StructDatumQuery,
+    TraitDatumQuery, TraitSolveQuery, TyQuery, ValueTyQuery,
 };
 
 #[test]
diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 7c1f79f27..a232a5856 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -122,8 +122,9 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         let macro_call =
             self.find_file(actual_macro_call.syntax().clone()).with_value(actual_macro_call);
         let sa = self.analyze2(macro_call.map(|it| it.syntax()), None);
+        let krate = sa.resolver.krate()?;
         let macro_call_id = macro_call
-            .as_call_id(self.db, |path| sa.resolver.resolve_path_as_macro(self.db, &path))?;
+            .as_call_id(self.db, krate, |path| sa.resolver.resolve_path_as_macro(self.db, &path))?;
         hir_expand::db::expand_hypothetical(self.db, macro_call_id, hypothetical_args, token_to_map)
     }
 
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index 4b509f07c..7c6bbea13 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -307,7 +307,8 @@ impl SourceAnalyzer {
         db: &dyn HirDatabase,
         macro_call: InFile<&ast::MacroCall>,
     ) -> Option<HirFileId> {
-        let macro_call_id = macro_call.as_call_id(db.upcast(), |path| {
+        let krate = self.resolver.krate()?;
+        let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
             self.resolver.resolve_path_as_macro(db.upcast(), &path)
         })?;
         Some(macro_call_id.as_file())
diff --git a/crates/ra_hir_def/Cargo.toml b/crates/ra_hir_def/Cargo.toml
index b85358308..ef1f65ee0 100644
--- a/crates/ra_hir_def/Cargo.toml
+++ b/crates/ra_hir_def/Cargo.toml
@@ -14,6 +14,9 @@ rustc-hash = "1.1.0"
 either = "1.5.3"
 anymap = "0.12.1"
 drop_bomb = "0.1.4"
+fst = { version = "0.4", default-features = false }
+itertools = "0.9.0"
+indexmap = "1.4.0"
 
 stdx = { path = "../stdx" }
 
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 8b6c0bede..2eeba0572 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -87,12 +87,18 @@ impl Attrs {
     }
 
     pub(crate) fn new(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
+        let docs = ast::CommentIter::from_syntax_node(owner.syntax()).doc_comment_text().map(
+            |docs_text| Attr {
+                input: Some(AttrInput::Literal(SmolStr::new(docs_text))),
+                path: ModPath::from(hir_expand::name!(doc)),
+            },
+        );
         let mut attrs = owner.attrs().peekable();
         let entries = if attrs.peek().is_none() {
             // Avoid heap allocation
             None
         } else {
-            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).chain(docs).collect())
         };
         Attrs { entries }
     }
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 273036cee..4f2350915 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -97,7 +97,7 @@ impl Expander {
 
         let macro_call = InFile::new(self.current_file_id, &macro_call);
 
-        if let Some(call_id) = macro_call.as_call_id(db, |path| {
+        if let Some(call_id) = macro_call.as_call_id(db, self.crate_def_map.krate, |path| {
             if let Some(local_scope) = local_scope {
                 if let Some(def) = path.as_ident().and_then(|n| local_scope.get_legacy_macro(n)) {
                     return Some(def);
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index e2130d931..53599e74a 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -34,6 +34,7 @@ pub struct FunctionData {
     /// True if the first param is `self`. This is relevant to decide whether this
     /// can be called as a method.
     pub has_self_param: bool,
+    pub is_unsafe: bool,
     pub visibility: RawVisibility,
 }
 
@@ -85,17 +86,20 @@ impl FunctionData {
             ret_type
         };
 
+        let is_unsafe = src.value.unsafe_token().is_some();
+
         let vis_default = RawVisibility::default_for_container(loc.container);
         let visibility =
             RawVisibility::from_ast_with_default(db, vis_default, src.map(|s| s.visibility()));
 
-        let sig = FunctionData { name, params, ret_type, has_self_param, visibility, attrs };
+        let sig =
+            FunctionData { name, params, ret_type, has_self_param, is_unsafe, visibility, attrs };
         Arc::new(sig)
     }
 }
 
 fn desugar_future_path(orig: TypeRef) -> Path {
-    let path = path![std::future::Future];
+    let path = path![core::future::Future];
     let mut generic_args: Vec<_> = std::iter::repeat(None).take(path.segments.len() - 1).collect();
     let mut last = GenericArgs::empty();
     last.bindings.push(AssociatedTypeBinding {
diff --git a/crates/ra_hir_def/src/db.rs b/crates/ra_hir_def/src/db.rs
index 945a0025e..10cc26480 100644
--- a/crates/ra_hir_def/src/db.rs
+++ b/crates/ra_hir_def/src/db.rs
@@ -1,7 +1,7 @@
 //! Defines database & queries for name resolution.
 use std::sync::Arc;
 
-use hir_expand::{db::AstDatabase, name::Name, HirFileId};
+use hir_expand::{db::AstDatabase, HirFileId};
 use ra_db::{salsa, CrateId, SourceDatabase, Upcast};
 use ra_prof::profile;
 use ra_syntax::SmolStr;
@@ -12,13 +12,10 @@ use crate::{
     body::{scope::ExprScopes, Body, BodySourceMap},
     data::{ConstData, FunctionData, ImplData, StaticData, TraitData, TypeAliasData},
     docs::Documentation,
-    find_path,
     generics::GenericParams,
-    item_scope::ItemInNs,
+    import_map::ImportMap,
     lang_item::{LangItemTarget, LangItems},
     nameres::{raw::RawItems, CrateDefMap},
-    path::ModPath,
-    visibility::Visibility,
     AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, EnumLoc, FunctionId, FunctionLoc,
     GenericDefId, ImplId, ImplLoc, ModuleId, StaticId, StaticLoc, StructId, StructLoc, TraitId,
     TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc,
@@ -113,15 +110,8 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
     #[salsa::invoke(Documentation::documentation_query)]
     fn documentation(&self, def: AttrDefId) -> Option<Documentation>;
 
-    #[salsa::invoke(find_path::importable_locations_of_query)]
-    fn importable_locations_of(
-        &self,
-        item: ItemInNs,
-        krate: CrateId,
-    ) -> Arc<[(ModuleId, Name, Visibility)]>;
-
-    #[salsa::invoke(find_path::find_path_inner_query)]
-    fn find_path_inner(&self, item: ItemInNs, from: ModuleId, max_len: usize) -> Option<ModPath>;
+    #[salsa::invoke(ImportMap::import_map_query)]
+    fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 }
 
 fn crate_def_map_wait(db: &impl DefDatabase, krate: CrateId) -> Arc<CrateDefMap> {
diff --git a/crates/ra_hir_def/src/docs.rs b/crates/ra_hir_def/src/docs.rs
index b221ae1ce..2630b3d89 100644
--- a/crates/ra_hir_def/src/docs.rs
+++ b/crates/ra_hir_def/src/docs.rs
@@ -29,6 +29,13 @@ impl Documentation {
         Documentation(s.into())
     }
 
+    pub fn from_ast<N>(node: &N) -> Option<Documentation>
+    where
+        N: ast::DocCommentsOwner + ast::AttrsOwner,
+    {
+        docs_from_ast(node)
+    }
+
     pub fn as_str(&self) -> &str {
         &*self.0
     }
@@ -70,6 +77,45 @@ impl Documentation {
     }
 }
 
-pub(crate) fn docs_from_ast(node: &impl ast::DocCommentsOwner) -> Option<Documentation> {
-    node.doc_comment_text().map(|it| Documentation::new(&it))
+pub(crate) fn docs_from_ast<N>(node: &N) -> Option<Documentation>
+where
+    N: ast::DocCommentsOwner + ast::AttrsOwner,
+{
+    let doc_comment_text = node.doc_comment_text();
+    let doc_attr_text = expand_doc_attrs(node);
+    let docs = merge_doc_comments_and_attrs(doc_comment_text, doc_attr_text);
+    docs.map(|it| Documentation::new(&it))
+}
+
+fn merge_doc_comments_and_attrs(
+    doc_comment_text: Option<String>,
+    doc_attr_text: Option<String>,
+) -> Option<String> {
+    match (doc_comment_text, doc_attr_text) {
+        (Some(mut comment_text), Some(attr_text)) => {
+            comment_text.push_str("\n\n");
+            comment_text.push_str(&attr_text);
+            Some(comment_text)
+        }
+        (Some(comment_text), None) => Some(comment_text),
+        (None, Some(attr_text)) => Some(attr_text),
+        (None, None) => None,
+    }
+}
+
+fn expand_doc_attrs(owner: &dyn ast::AttrsOwner) -> Option<String> {
+    let mut docs = String::new();
+    for attr in owner.attrs() {
+        if let Some(("doc", value)) =
+            attr.as_simple_key_value().as_ref().map(|(k, v)| (k.as_str(), v.as_str()))
+        {
+            docs.push_str(value);
+            docs.push_str("\n\n");
+        }
+    }
+    if docs.is_empty() {
+        None
+    } else {
+        Some(docs.trim_end_matches("\n\n").to_owned())
+    }
 }
diff --git a/crates/ra_hir_def/src/find_path.rs b/crates/ra_hir_def/src/find_path.rs
index 4db798473..06701a830 100644
--- a/crates/ra_hir_def/src/find_path.rs
+++ b/crates/ra_hir_def/src/find_path.rs
@@ -1,9 +1,8 @@
 //! An algorithm to find a path to refer to a certain item.
 
-use std::sync::Arc;
-
 use hir_expand::name::{known, AsName, Name};
 use ra_prof::profile;
+use rustc_hash::FxHashSet;
 use test_utils::mark;
 
 use crate::{
@@ -11,7 +10,7 @@ use crate::{
     item_scope::ItemInNs,
     path::{ModPath, PathKind},
     visibility::Visibility,
-    CrateId, ModuleDefId, ModuleId,
+    ModuleDefId, ModuleId,
 };
 
 // FIXME: handle local items
@@ -20,7 +19,7 @@ use crate::{
 /// *from where* you're referring to the item, hence the `from` parameter.
 pub fn find_path(db: &dyn DefDatabase, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
     let _p = profile("find_path");
-    db.find_path_inner(item, from, MAX_PATH_LEN)
+    find_path_inner(db, item, from, MAX_PATH_LEN)
 }
 
 const MAX_PATH_LEN: usize = 15;
@@ -36,20 +35,9 @@ impl ModPath {
         let first_segment = self.segments.first();
         first_segment == Some(&known::alloc) || first_segment == Some(&known::core)
     }
-
-    fn len(&self) -> usize {
-        self.segments.len()
-            + match self.kind {
-                PathKind::Plain => 0,
-                PathKind::Super(i) => i as usize,
-                PathKind::Crate => 1,
-                PathKind::Abs => 0,
-                PathKind::DollarCrate(_) => 1,
-            }
-    }
 }
 
-pub(crate) fn find_path_inner_query(
+fn find_path_inner(
     db: &dyn DefDatabase,
     item: ItemInNs,
     from: ModuleId,
@@ -133,31 +121,67 @@ pub(crate) fn find_path_inner_query(
     }
 
     // - otherwise, look for modules containing (reexporting) it and import it from one of those
+
     let crate_root = ModuleId { local_id: def_map.root, krate: from.krate };
     let crate_attrs = db.attrs(crate_root.into());
     let prefer_no_std = crate_attrs.by_key("no_std").exists();
-    let importable_locations = find_importable_locations(db, item, from);
     let mut best_path = None;
     let mut best_path_len = max_len;
-    for (module_id, name) in importable_locations {
-        let mut path = match db.find_path_inner(
-            ItemInNs::Types(ModuleDefId::ModuleId(module_id)),
-            from,
-            best_path_len - 1,
-        ) {
-            None => continue,
-            Some(path) => path,
-        };
-        path.segments.push(name);
 
-        let new_path = if let Some(best_path) = best_path {
-            select_best_path(best_path, path, prefer_no_std)
-        } else {
-            path
-        };
-        best_path_len = new_path.len();
-        best_path = Some(new_path);
+    if item.krate(db) == Some(from.krate) {
+        // Item was defined in the same crate that wants to import it. It cannot be found in any
+        // dependency in this case.
+
+        let local_imports = find_local_import_locations(db, item, from);
+        for (module_id, name) in local_imports {
+            if let Some(mut path) = find_path_inner(
+                db,
+                ItemInNs::Types(ModuleDefId::ModuleId(module_id)),
+                from,
+                best_path_len - 1,
+            ) {
+                path.segments.push(name);
+
+                let new_path = if let Some(best_path) = best_path {
+                    select_best_path(best_path, path, prefer_no_std)
+                } else {
+                    path
+                };
+                best_path_len = new_path.len();
+                best_path = Some(new_path);
+            }
+        }
+    } else {
+        // Item was defined in some upstream crate. This means that it must be exported from one,
+        // too (unless we can't name it at all). It could *also* be (re)exported by the same crate
+        // that wants to import it here, but we always prefer to use the external path here.
+
+        let crate_graph = db.crate_graph();
+        let extern_paths = crate_graph[from.krate].dependencies.iter().filter_map(|dep| {
+            let import_map = db.import_map(dep.crate_id);
+            import_map.import_info_for(item).and_then(|info| {
+                // Determine best path for containing module and append last segment from `info`.
+                let mut path = find_path_inner(
+                    db,
+                    ItemInNs::Types(ModuleDefId::ModuleId(info.container)),
+                    from,
+                    best_path_len - 1,
+                )?;
+                path.segments.push(info.path.segments.last().unwrap().clone());
+                Some(path)
+            })
+        });
+
+        for path in extern_paths {
+            let new_path = if let Some(best_path) = best_path {
+                select_best_path(best_path, path, prefer_no_std)
+            } else {
+                path
+            };
+            best_path = Some(new_path);
+        }
     }
+
     best_path
 }
 
@@ -185,69 +209,86 @@ fn select_best_path(old_path: ModPath, new_path: ModPath, prefer_no_std: bool) -
     }
 }
 
-fn find_importable_locations(
+/// Finds locations in `from.krate` from which `item` can be imported by `from`.
+fn find_local_import_locations(
     db: &dyn DefDatabase,
     item: ItemInNs,
     from: ModuleId,
 ) -> Vec<(ModuleId, Name)> {
-    let crate_graph = db.crate_graph();
-    let mut result = Vec::new();
-    // We only look in the crate from which we are importing, and the direct
-    // dependencies. We cannot refer to names from transitive dependencies
-    // directly (only through reexports in direct dependencies).
-    for krate in Some(from.krate)
-        .into_iter()
-        .chain(crate_graph[from.krate].dependencies.iter().map(|dep| dep.crate_id))
-    {
-        result.extend(
-            db.importable_locations_of(item, krate)
-                .iter()
-                .filter(|(_, _, vis)| vis.is_visible_from(db, from))
-                .map(|(m, n, _)| (*m, n.clone())),
-        );
-    }
-    result
-}
+    let _p = profile("find_local_import_locations");
+
+    // `from` can import anything below `from` with visibility of at least `from`, and anything
+    // above `from` with any visibility. That means we do not need to descend into private siblings
+    // of `from` (and similar).
+
+    let def_map = db.crate_def_map(from.krate);
+
+    // Compute the initial worklist. We start with all direct child modules of `from` as well as all
+    // of its (recursive) parent modules.
+    let data = &def_map.modules[from.local_id];
+    let mut worklist = data
+        .children
+        .values()
+        .map(|child| ModuleId { krate: from.krate, local_id: *child })
+        .collect::<Vec<_>>();
+    let mut parent = data.parent;
+    while let Some(p) = parent {
+        worklist.push(ModuleId { krate: from.krate, local_id: p });
+        parent = def_map.modules[p].parent;
+    }
+
+    let mut seen: FxHashSet<_> = FxHashSet::default();
+
+    let mut locations = Vec::new();
+    while let Some(module) = worklist.pop() {
+        if !seen.insert(module) {
+            continue; // already processed this module
+        }
+
+        let ext_def_map;
+        let data = if module.krate == from.krate {
+            &def_map[module.local_id]
+        } else {
+            // The crate might reexport a module defined in another crate.
+            ext_def_map = db.crate_def_map(module.krate);
+            &ext_def_map[module.local_id]
+        };
 
-/// Collects all locations from which we might import the item in a particular
-/// crate. These include the original definition of the item, and any
-/// non-private `use`s.
-///
-/// Note that the crate doesn't need to be the one in which the item is defined;
-/// it might be re-exported in other crates.
-pub(crate) fn importable_locations_of_query(
-    db: &dyn DefDatabase,
-    item: ItemInNs,
-    krate: CrateId,
-) -> Arc<[(ModuleId, Name, Visibility)]> {
-    let _p = profile("importable_locations_of_query");
-    let def_map = db.crate_def_map(krate);
-    let mut result = Vec::new();
-    for (local_id, data) in def_map.modules.iter() {
         if let Some((name, vis)) = data.scope.name_of(item) {
-            let is_private = if let Visibility::Module(private_to) = vis {
-                private_to.local_id == local_id
-            } else {
-                false
-            };
-            let is_original_def = if let Some(module_def_id) = item.as_module_def_id() {
-                data.scope.declarations().any(|it| it == module_def_id)
-            } else {
-                false
-            };
-            if is_private && !is_original_def {
+            if vis.is_visible_from(db, from) {
+                let is_private = if let Visibility::Module(private_to) = vis {
+                    private_to.local_id == module.local_id
+                } else {
+                    false
+                };
+                let is_original_def = if let Some(module_def_id) = item.as_module_def_id() {
+                    data.scope.declarations().any(|it| it == module_def_id)
+                } else {
+                    false
+                };
+
                 // Ignore private imports. these could be used if we are
                 // in a submodule of this module, but that's usually not
                 // what the user wants; and if this module can import
                 // the item and we're a submodule of it, so can we.
                 // Also this keeps the cached data smaller.
-                continue;
+                if !is_private || is_original_def {
+                    locations.push((module, name.clone()));
+                }
+            }
+        }
+
+        // Descend into all modules visible from `from`.
+        for (_, per_ns) in data.scope.entries() {
+            if let Some((ModuleDefId::ModuleId(module), vis)) = per_ns.take_types_vis() {
+                if vis.is_visible_from(db, from) {
+                    worklist.push(module);
+                }
             }
-            result.push((ModuleId { krate, local_id }, name.clone(), vis));
         }
     }
 
-    Arc::from(result)
+    locations
 }
 
 #[cfg(test)]
@@ -264,8 +305,8 @@ mod tests {
     /// `code` needs to contain a cursor marker; checks that `find_path` for the
     /// item the `path` refers to returns that same path when called from the
     /// module the cursor is in.
-    fn check_found_path(code: &str, path: &str) {
-        let (db, pos) = TestDB::with_position(code);
+    fn check_found_path(ra_fixture: &str, path: &str) {
+        let (db, pos) = TestDB::with_position(ra_fixture);
         let module = db.module_for_file(pos.file_id);
         let parsed_path_file = ra_syntax::SourceFile::parse(&format!("use {};", path));
         let ast_path = parsed_path_file
@@ -396,6 +437,44 @@ mod tests {
     }
 
     #[test]
+    fn partially_imported() {
+        // Tests that short paths are used even for external items, when parts of the path are
+        // already in scope.
+        check_found_path(
+            r#"
+            //- /main.rs crate:main deps:ra_syntax
+
+            use ra_syntax::ast;
+            <|>
+
+            //- /lib.rs crate:ra_syntax
+            pub mod ast {
+                pub enum ModuleItem {
+                    A, B, C,
+                }
+            }
+        "#,
+            "ast::ModuleItem",
+        );
+
+        check_found_path(
+            r#"
+            //- /main.rs crate:main deps:ra_syntax
+
+            <|>
+
+            //- /lib.rs crate:ra_syntax
+            pub mod ast {
+                pub enum ModuleItem {
+                    A, B, C,
+                }
+            }
+        "#,
+            "ra_syntax::ast::ModuleItem",
+        );
+    }
+
+    #[test]
     fn same_crate_reexport() {
         let code = r#"
             //- /main.rs
diff --git a/crates/ra_hir_def/src/import_map.rs b/crates/ra_hir_def/src/import_map.rs
new file mode 100644
index 000000000..68e20d06b
--- /dev/null
+++ b/crates/ra_hir_def/src/import_map.rs
@@ -0,0 +1,679 @@
+//! A map of all publicly exported items in a crate.
+
+use std::{cmp::Ordering, fmt, hash::BuildHasherDefault, sync::Arc};
+
+use fst::{self, Streamer};
+use indexmap::{map::Entry, IndexMap};
+use ra_db::CrateId;
+use rustc_hash::FxHasher;
+
+use crate::{
+    db::DefDatabase,
+    item_scope::ItemInNs,
+    path::{ModPath, PathKind},
+    visibility::Visibility,
+    ModuleDefId, ModuleId,
+};
+
+type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
+
+/// Item import details stored in the `ImportMap`.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct ImportInfo {
+    /// A path that can be used to import the item, relative to the crate's root.
+    pub path: ModPath,
+    /// The module containing this item.
+    pub container: ModuleId,
+}
+
+/// A map from publicly exported items to the path needed to import/name them from a downstream
+/// crate.
+///
+/// Reexports of items are taken into account, ie. if something is exported under multiple
+/// names, the one with the shortest import path will be used.
+///
+/// Note that all paths are relative to the containing crate's root, so the crate name still needs
+/// to be prepended to the `ModPath` before the path is valid.
+pub struct ImportMap {
+    map: FxIndexMap<ItemInNs, ImportInfo>,
+
+    /// List of keys stored in `map`, sorted lexicographically by their `ModPath`. Indexed by the
+    /// values returned by running `fst`.
+    ///
+    /// Since a path can refer to multiple items due to namespacing, we store all items with the
+    /// same path right after each other. This allows us to find all items after the FST gives us
+    /// the index of the first one.
+    importables: Vec<ItemInNs>,
+    fst: fst::Map<Vec<u8>>,
+}
+
+impl ImportMap {
+    pub fn import_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<Self> {
+        let _p = ra_prof::profile("import_map_query");
+        let def_map = db.crate_def_map(krate);
+        let mut import_map = FxIndexMap::with_capacity_and_hasher(64, Default::default());
+
+        // We look only into modules that are public(ly reexported), starting with the crate root.
+        let empty = ModPath { kind: PathKind::Plain, segments: vec![] };
+        let root = ModuleId { krate, local_id: def_map.root };
+        let mut worklist = vec![(root, empty)];
+        while let Some((module, mod_path)) = worklist.pop() {
+            let ext_def_map;
+            let mod_data = if module.krate == krate {
+                &def_map[module.local_id]
+            } else {
+                // The crate might reexport a module defined in another crate.
+                ext_def_map = db.crate_def_map(module.krate);
+                &ext_def_map[module.local_id]
+            };
+
+            let visible_items = mod_data.scope.entries().filter_map(|(name, per_ns)| {
+                let per_ns = per_ns.filter_visibility(|vis| vis == Visibility::Public);
+                if per_ns.is_none() {
+                    None
+                } else {
+                    Some((name, per_ns))
+                }
+            });
+
+            for (name, per_ns) in visible_items {
+                let mk_path = || {
+                    let mut path = mod_path.clone();
+                    path.segments.push(name.clone());
+                    path
+                };
+
+                for item in per_ns.iter_items() {
+                    let path = mk_path();
+                    match import_map.entry(item) {
+                        Entry::Vacant(entry) => {
+                            entry.insert(ImportInfo { path, container: module });
+                        }
+                        Entry::Occupied(mut entry) => {
+                            // If the new path is shorter, prefer that one.
+                            if path.len() < entry.get().path.len() {
+                                *entry.get_mut() = ImportInfo { path, container: module };
+                            } else {
+                                continue;
+                            }
+                        }
+                    }
+
+                    // If we've just added a path to a module, descend into it. We might traverse
+                    // modules multiple times, but only if the new path to it is shorter than the
+                    // first (else we `continue` above).
+                    if let Some(ModuleDefId::ModuleId(mod_id)) = item.as_module_def_id() {
+                        worklist.push((mod_id, mk_path()));
+                    }
+                }
+            }
+        }
+
+        let mut importables = import_map.iter().collect::<Vec<_>>();
+
+        importables.sort_by(cmp);
+
+        // Build the FST, taking care not to insert duplicate values.
+
+        let mut builder = fst::MapBuilder::memory();
+        let mut last_batch_start = 0;
+
+        for idx in 0..importables.len() {
+            if let Some(next_item) = importables.get(idx + 1) {
+                if cmp(&importables[last_batch_start], next_item) == Ordering::Equal {
+                    continue;
+                }
+            }
+
+            let start = last_batch_start;
+            last_batch_start = idx + 1;
+
+            let key = fst_path(&importables[start].1.path);
+
+            builder.insert(key, start as u64).unwrap();
+        }
+
+        let fst = fst::Map::new(builder.into_inner().unwrap()).unwrap();
+        let importables = importables.iter().map(|(item, _)| **item).collect();
+
+        Arc::new(Self { map: import_map, fst, importables })
+    }
+
+    /// Returns the `ModPath` needed to import/mention `item`, relative to this crate's root.
+    pub fn path_of(&self, item: ItemInNs) -> Option<&ModPath> {
+        Some(&self.map.get(&item)?.path)
+    }
+
+    pub fn import_info_for(&self, item: ItemInNs) -> Option<&ImportInfo> {
+        self.map.get(&item)
+    }
+}
+
+impl PartialEq for ImportMap {
+    fn eq(&self, other: &Self) -> bool {
+        // `fst` and `importables` are built from `map`, so we don't need to compare them.
+        self.map == other.map
+    }
+}
+
+impl Eq for ImportMap {}
+
+impl fmt::Debug for ImportMap {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut importable_paths: Vec<_> = self
+            .map
+            .iter()
+            .map(|(item, info)| {
+                let ns = match item {
+                    ItemInNs::Types(_) => "t",
+                    ItemInNs::Values(_) => "v",
+                    ItemInNs::Macros(_) => "m",
+                };
+                format!("- {} ({})", info.path, ns)
+            })
+            .collect();
+
+        importable_paths.sort();
+        f.write_str(&importable_paths.join("\n"))
+    }
+}
+
+fn fst_path(path: &ModPath) -> String {
+    let mut s = path.to_string();
+    s.make_ascii_lowercase();
+    s
+}
+
+fn cmp((_, lhs): &(&ItemInNs, &ImportInfo), (_, rhs): &(&ItemInNs, &ImportInfo)) -> Ordering {
+    let lhs_str = fst_path(&lhs.path);
+    let rhs_str = fst_path(&rhs.path);
+    lhs_str.cmp(&rhs_str)
+}
+
+#[derive(Debug)]
+pub struct Query {
+    query: String,
+    lowercased: String,
+    anchor_end: bool,
+    case_sensitive: bool,
+    limit: usize,
+}
+
+impl Query {
+    pub fn new(query: &str) -> Self {
+        Self {
+            lowercased: query.to_lowercase(),
+            query: query.to_string(),
+            anchor_end: false,
+            case_sensitive: false,
+            limit: usize::max_value(),
+        }
+    }
+
+    /// Only returns items whose paths end with the (case-insensitive) query string as their last
+    /// segment.
+    pub fn anchor_end(self) -> Self {
+        Self { anchor_end: true, ..self }
+    }
+
+    /// Limits the returned number of items to `limit`.
+    pub fn limit(self, limit: usize) -> Self {
+        Self { limit, ..self }
+    }
+
+    /// Respect casing of the query string when matching.
+    pub fn case_sensitive(self) -> Self {
+        Self { case_sensitive: true, ..self }
+    }
+}
+
+/// Searches dependencies of `krate` for an importable path matching `query`.
+///
+/// This returns a list of items that could be imported from dependencies of `krate`.
+pub fn search_dependencies<'a>(
+    db: &'a dyn DefDatabase,
+    krate: CrateId,
+    query: Query,
+) -> Vec<ItemInNs> {
+    let _p = ra_prof::profile("search_dependencies").detail(|| format!("{:?}", query));
+
+    let graph = db.crate_graph();
+    let import_maps: Vec<_> =
+        graph[krate].dependencies.iter().map(|dep| db.import_map(dep.crate_id)).collect();
+
+    let automaton = fst::automaton::Subsequence::new(&query.lowercased);
+
+    let mut op = fst::map::OpBuilder::new();
+    for map in &import_maps {
+        op = op.add(map.fst.search(&automaton));
+    }
+
+    let mut stream = op.union();
+    let mut res = Vec::new();
+    while let Some((_, indexed_values)) = stream.next() {
+        for indexed_value in indexed_values {
+            let import_map = &import_maps[indexed_value.index];
+            let importables = &import_map.importables[indexed_value.value as usize..];
+
+            // Path shared by the importable items in this group.
+            let path = &import_map.map[&importables[0]].path;
+
+            if query.anchor_end {
+                // Last segment must match query.
+                let last = path.segments.last().unwrap().to_string();
+                if last.to_lowercase() != query.lowercased {
+                    continue;
+                }
+            }
+
+            // Add the items from this `ModPath` group. Those are all subsequent items in
+            // `importables` whose paths match `path`.
+            let iter = importables.iter().copied().take_while(|item| {
+                let item_path = &import_map.map[item].path;
+                fst_path(item_path) == fst_path(path)
+            });
+
+            if query.case_sensitive {
+                // FIXME: This does not do a subsequence match.
+                res.extend(iter.filter(|item| {
+                    let item_path = &import_map.map[item].path;
+                    item_path.to_string().contains(&query.query)
+                }));
+            } else {
+                res.extend(iter);
+            }
+
+            if res.len() >= query.limit {
+                res.truncate(query.limit);
+                return res;
+            }
+        }
+    }
+
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_db::TestDB;
+    use insta::assert_snapshot;
+    use itertools::Itertools;
+    use ra_db::fixture::WithFixture;
+    use ra_db::{SourceDatabase, Upcast};
+
+    fn import_map(ra_fixture: &str) -> String {
+        let db = TestDB::with_files(ra_fixture);
+        let crate_graph = db.crate_graph();
+
+        let s = crate_graph
+            .iter()
+            .filter_map(|krate| {
+                let cdata = &crate_graph[krate];
+                let name = cdata.display_name.as_ref()?;
+
+                let map = db.import_map(krate);
+
+                Some(format!("{}:\n{:?}", name, map))
+            })
+            .join("\n");
+        s
+    }
+
+    fn search_dependencies_of(ra_fixture: &str, krate_name: &str, query: Query) -> String {
+        let db = TestDB::with_files(ra_fixture);
+        let crate_graph = db.crate_graph();
+        let krate = crate_graph
+            .iter()
+            .find(|krate| {
+                crate_graph[*krate].display_name.as_ref().map(|n| n.to_string())
+                    == Some(krate_name.to_string())
+            })
+            .unwrap();
+
+        search_dependencies(db.upcast(), krate, query)
+            .into_iter()
+            .filter_map(|item| {
+                let mark = match item {
+                    ItemInNs::Types(_) => "t",
+                    ItemInNs::Values(_) => "v",
+                    ItemInNs::Macros(_) => "m",
+                };
+                item.krate(db.upcast()).map(|krate| {
+                    let map = db.import_map(krate);
+                    let path = map.path_of(item).unwrap();
+                    format!(
+                        "{}::{} ({})",
+                        crate_graph[krate].display_name.as_ref().unwrap(),
+                        path,
+                        mark
+                    )
+                })
+            })
+            .join("\n")
+    }
+
+    #[test]
+    fn smoke() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+
+            mod private {
+                pub use lib::Pub;
+                pub struct InPrivateModule;
+            }
+
+            pub mod publ1 {
+                use lib::Pub;
+            }
+
+            pub mod real_pub {
+                pub use lib::Pub;
+            }
+            pub mod real_pu2 { // same path length as above
+                pub use lib::Pub;
+            }
+
+            //- /lib.rs crate:lib
+            pub struct Pub {}
+            pub struct Pub2; // t + v
+            struct Priv;
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - publ1 (t)
+        - real_pu2 (t)
+        - real_pub (t)
+        - real_pub::Pub (t)
+        lib:
+        - Pub (t)
+        - Pub2 (t)
+        - Pub2 (v)
+        "###);
+    }
+
+    #[test]
+    fn prefers_shortest_path() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main
+
+            pub mod sub {
+                pub mod subsub {
+                    pub struct Def {}
+                }
+
+                pub use super::sub::subsub::Def;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - sub (t)
+        - sub::Def (t)
+        - sub::subsub (t)
+        "###);
+    }
+
+    #[test]
+    fn type_reexport_cross_crate() {
+        // Reexports need to be visible from a crate, even if the original crate exports the item
+        // at a shorter path.
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub mod m {
+                pub use lib::S;
+            }
+            //- /lib.rs crate:lib
+            pub struct S;
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - m (t)
+        - m::S (t)
+        - m::S (v)
+        lib:
+        - S (t)
+        - S (v)
+        "###);
+    }
+
+    #[test]
+    fn macro_reexport() {
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub mod m {
+                pub use lib::pub_macro;
+            }
+            //- /lib.rs crate:lib
+            #[macro_export]
+            macro_rules! pub_macro {
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - m (t)
+        - m::pub_macro (m)
+        lib:
+        - pub_macro (m)
+        "###);
+    }
+
+    #[test]
+    fn module_reexport() {
+        // Reexporting modules from a dependency adds all contents to the import map.
+        let map = import_map(
+            r"
+            //- /main.rs crate:main deps:lib
+            pub use lib::module as reexported_module;
+            //- /lib.rs crate:lib
+            pub mod module {
+                pub struct S;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        main:
+        - reexported_module (t)
+        - reexported_module::S (t)
+        - reexported_module::S (v)
+        lib:
+        - module (t)
+        - module::S (t)
+        - module::S (v)
+        "###);
+    }
+
+    #[test]
+    fn cyclic_module_reexport() {
+        // A cyclic reexport does not hang.
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub mod module {
+                pub struct S;
+                pub use super::sub::*;
+            }
+
+            pub mod sub {
+                pub use super::module;
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - module (t)
+        - module::S (t)
+        - module::S (v)
+        - sub (t)
+        "###);
+    }
+
+    #[test]
+    fn private_macro() {
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            macro_rules! private_macro {
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        "###);
+    }
+
+    #[test]
+    fn namespacing() {
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub struct Thing;     // t + v
+            #[macro_export]
+            macro_rules! Thing {  // m
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - Thing (m)
+        - Thing (t)
+        - Thing (v)
+        "###);
+
+        let map = import_map(
+            r"
+            //- /lib.rs crate:lib
+            pub mod Thing {}      // t
+            #[macro_export]
+            macro_rules! Thing {  // m
+                () => {};
+            }
+        ",
+        );
+
+        assert_snapshot!(map, @r###"
+        lib:
+        - Thing (m)
+        - Thing (t)
+        "###);
+    }
+
+    #[test]
+    fn search() {
+        let ra_fixture = r#"
+            //- /main.rs crate:main deps:dep
+            //- /dep.rs crate:dep deps:tdep
+            use tdep::fmt as fmt_dep;
+            pub mod fmt {
+                pub trait Display {
+                    fn fmt();
+                }
+            }
+            #[macro_export]
+            macro_rules! Fmt {
+                () => {};
+            }
+            pub struct Fmt;
+
+            pub fn format() {}
+            pub fn no() {}
+
+            //- /tdep.rs crate:tdep
+            pub mod fmt {
+                pub struct NotImportableFromMain;
+            }
+        "#;
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("fmt"));
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        dep::Fmt (v)
+        dep::Fmt (m)
+        dep::fmt::Display (t)
+        dep::format (v)
+        "###);
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("fmt").anchor_end());
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        dep::Fmt (v)
+        dep::Fmt (m)
+        "###);
+    }
+
+    #[test]
+    fn search_casing() {
+        let ra_fixture = r#"
+            //- /main.rs crate:main deps:dep
+            //- /dep.rs crate:dep
+
+            pub struct fmt;
+            pub struct FMT;
+        "#;
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("FMT"));
+
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::fmt (v)
+        dep::FMT (t)
+        dep::FMT (v)
+        "###);
+
+        let res = search_dependencies_of(ra_fixture, "main", Query::new("FMT").case_sensitive());
+
+        assert_snapshot!(res, @r###"
+        dep::FMT (t)
+        dep::FMT (v)
+        "###);
+    }
+
+    #[test]
+    fn search_limit() {
+        let res = search_dependencies_of(
+            r#"
+        //- /main.rs crate:main deps:dep
+        //- /dep.rs crate:dep
+        pub mod fmt {
+            pub trait Display {
+                fn fmt();
+            }
+        }
+        #[macro_export]
+        macro_rules! Fmt {
+            () => {};
+        }
+        pub struct Fmt;
+
+        pub fn format() {}
+        pub fn no() {}
+    "#,
+            "main",
+            Query::new("").limit(2),
+        );
+        assert_snapshot!(res, @r###"
+        dep::fmt (t)
+        dep::Fmt (t)
+        "###);
+    }
+}
diff --git a/crates/ra_hir_def/src/item_scope.rs b/crates/ra_hir_def/src/item_scope.rs
index fc15948ad..b03ba939a 100644
--- a/crates/ra_hir_def/src/item_scope.rs
+++ b/crates/ra_hir_def/src/item_scope.rs
@@ -3,11 +3,12 @@
 
 use hir_expand::name::Name;
 use once_cell::sync::Lazy;
+use ra_db::CrateId;
 use rustc_hash::FxHashMap;
 
 use crate::{
-    per_ns::PerNs, visibility::Visibility, AdtId, BuiltinType, ImplId, MacroDefId, ModuleDefId,
-    TraitId,
+    db::DefDatabase, per_ns::PerNs, visibility::Visibility, AdtId, BuiltinType, HasModule, ImplId,
+    Lookup, MacroDefId, ModuleDefId, TraitId,
 };
 
 #[derive(Debug, Default, PartialEq, Eq)]
@@ -203,4 +204,22 @@ impl ItemInNs {
             ItemInNs::Macros(_) => None,
         }
     }
+
+    /// Returns the crate defining this item (or `None` if `self` is built-in).
+    pub fn krate(&self, db: &dyn DefDatabase) -> Option<CrateId> {
+        Some(match self {
+            ItemInNs::Types(did) | ItemInNs::Values(did) => match did {
+                ModuleDefId::ModuleId(id) => id.krate,
+                ModuleDefId::FunctionId(id) => id.lookup(db).module(db).krate,
+                ModuleDefId::AdtId(id) => id.module(db).krate,
+                ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container.module(db).krate,
+                ModuleDefId::ConstId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::StaticId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::TraitId(id) => id.lookup(db).container.module(db).krate,
+                ModuleDefId::TypeAliasId(id) => id.lookup(db).module(db).krate,
+                ModuleDefId::BuiltinType(_) => return None,
+            },
+            ItemInNs::Macros(id) => return id.krate,
+        })
+    }
 }
diff --git a/crates/ra_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index 5325a2760..edc59e5a8 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -43,6 +43,7 @@ pub mod child_by_source;
 
 pub mod visibility;
 pub mod find_path;
+pub mod import_map;
 
 #[cfg(test)]
 mod test_db;
@@ -416,6 +417,7 @@ pub trait AsMacroCall {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId>;
 }
@@ -424,13 +426,14 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
         let h = Hygiene::new(db.upcast(), self.file_id);
         let path = path::ModPath::from_src(self.value.path()?, &h)?;
 
-        AstIdWithPath::new(ast_id.file_id, ast_id.value, path).as_call_id(db, resolver)
+        AstIdWithPath::new(ast_id.file_id, ast_id.value, path).as_call_id(db, krate, resolver)
     }
 }
 
@@ -451,6 +454,7 @@ impl AsMacroCall for AstIdWithPath<ast::MacroCall> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let def: MacroDefId = resolver(self.path.clone())?;
@@ -460,13 +464,13 @@ impl AsMacroCall for AstIdWithPath<ast::MacroCall> {
             let hygiene = Hygiene::new(db.upcast(), self.ast_id.file_id);
 
             Some(
-                expand_eager_macro(db.upcast(), macro_call, def, &|path: ast::Path| {
+                expand_eager_macro(db.upcast(), krate, macro_call, def, &|path: ast::Path| {
                     resolver(path::ModPath::from_src(path, &hygiene)?)
                 })?
                 .into(),
             )
         } else {
-            Some(def.as_lazy_macro(db.upcast(), MacroCallKind::FnLike(self.ast_id)).into())
+            Some(def.as_lazy_macro(db.upcast(), krate, MacroCallKind::FnLike(self.ast_id)).into())
         }
     }
 }
@@ -475,12 +479,14 @@ impl AsMacroCall for AstIdWithPath<ast::ModuleItem> {
     fn as_call_id(
         &self,
         db: &dyn db::DefDatabase,
+        krate: CrateId,
         resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
     ) -> Option<MacroCallId> {
         let def = resolver(self.path.clone())?;
         Some(
             def.as_lazy_macro(
                 db.upcast(),
+                krate,
                 MacroCallKind::Attr(self.ast_id, self.path.segments.last()?.to_string()),
             )
             .into(),
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 353a31ad4..976e5e585 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -571,16 +571,18 @@ impl DefCollector<'_> {
                 return false;
             }
 
-            if let Some(call_id) = directive.ast_id.as_call_id(self.db, |path| {
-                let resolved_res = self.def_map.resolve_path_fp_with_macro(
-                    self.db,
-                    ResolveMode::Other,
-                    directive.module_id,
-                    &path,
-                    BuiltinShadowMode::Module,
-                );
-                resolved_res.resolved_def.take_macros()
-            }) {
+            if let Some(call_id) =
+                directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| {
+                    let resolved_res = self.def_map.resolve_path_fp_with_macro(
+                        self.db,
+                        ResolveMode::Other,
+                        directive.module_id,
+                        &path,
+                        BuiltinShadowMode::Module,
+                    );
+                    resolved_res.resolved_def.take_macros()
+                })
+            {
                 resolved.push((directive.module_id, call_id, directive.depth));
                 res = ReachedFixedPoint::No;
                 return false;
@@ -589,9 +591,10 @@ impl DefCollector<'_> {
             true
         });
         attribute_macros.retain(|directive| {
-            if let Some(call_id) = directive
-                .ast_id
-                .as_call_id(self.db, |path| self.resolve_attribute_macro(&directive, &path))
+            if let Some(call_id) =
+                directive.ast_id.as_call_id(self.db, self.def_map.krate, |path| {
+                    self.resolve_attribute_macro(&directive, &path)
+                })
             {
                 resolved.push((directive.module_id, call_id, 0));
                 res = ReachedFixedPoint::No;
@@ -957,11 +960,13 @@ impl ModCollector<'_, '_> {
         }
 
         // Case 2: try to resolve in legacy scope and expand macro_rules
-        if let Some(macro_call_id) = ast_id.as_call_id(self.def_collector.db, |path| {
-            path.as_ident().and_then(|name| {
-                self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+        if let Some(macro_call_id) =
+            ast_id.as_call_id(self.def_collector.db, self.def_collector.def_map.krate, |path| {
+                path.as_ident().and_then(|name| {
+                    self.def_collector.def_map[self.module_id].scope.get_legacy_macro(&name)
+                })
             })
-        }) {
+        {
             self.def_collector.unexpanded_macros.push(MacroDirective {
                 module_id: self.module_id,
                 ast_id,
diff --git a/crates/ra_hir_def/src/nameres/mod_resolution.rs b/crates/ra_hir_def/src/nameres/mod_resolution.rs
index 386c5cade..cede4a6fc 100644
--- a/crates/ra_hir_def/src/nameres/mod_resolution.rs
+++ b/crates/ra_hir_def/src/nameres/mod_resolution.rs
@@ -61,7 +61,7 @@ impl ModDir {
         };
 
         for candidate in candidate_files.iter() {
-            if let Some(file_id) = db.resolve_relative_path(file_id, candidate) {
+            if let Some(file_id) = db.resolve_path(file_id, candidate.as_str()) {
                 let mut root_non_dir_owner = false;
                 let mut mod_path = RelativePathBuf::new();
                 if !(candidate.ends_with("mod.rs") || attr_path.is_some()) {
diff --git a/crates/ra_hir_def/src/path.rs b/crates/ra_hir_def/src/path.rs
index e84efe2ab..ba16442bd 100644
--- a/crates/ra_hir_def/src/path.rs
+++ b/crates/ra_hir_def/src/path.rs
@@ -76,6 +76,19 @@ impl ModPath {
         }
     }
 
+    /// Returns the number of segments in the path (counting special segments like `$crate` and
+    /// `super`).
+    pub fn len(&self) -> usize {
+        self.segments.len()
+            + match self.kind {
+                PathKind::Plain => 0,
+                PathKind::Super(i) => i as usize,
+                PathKind::Crate => 1,
+                PathKind::Abs => 0,
+                PathKind::DollarCrate(_) => 1,
+            }
+    }
+
     pub fn is_ident(&self) -> bool {
         self.kind == PathKind::Plain && self.segments.len() == 1
     }
@@ -273,7 +286,7 @@ impl From<Name> for ModPath {
 impl Display for ModPath {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut first_segment = true;
-        let mut add_segment = |s| {
+        let mut add_segment = |s| -> fmt::Result {
             if !first_segment {
                 f.write_str("::")?;
             }
@@ -310,16 +323,16 @@ pub use hir_expand::name as __name;
 
 #[macro_export]
 macro_rules! __known_path {
-    (std::iter::IntoIterator) => {};
-    (std::result::Result) => {};
-    (std::ops::Range) => {};
-    (std::ops::RangeFrom) => {};
-    (std::ops::RangeFull) => {};
-    (std::ops::RangeTo) => {};
-    (std::ops::RangeToInclusive) => {};
-    (std::ops::RangeInclusive) => {};
-    (std::future::Future) => {};
-    (std::ops::Try) => {};
+    (core::iter::IntoIterator) => {};
+    (core::result::Result) => {};
+    (core::ops::Range) => {};
+    (core::ops::RangeFrom) => {};
+    (core::ops::RangeFull) => {};
+    (core::ops::RangeTo) => {};
+    (core::ops::RangeToInclusive) => {};
+    (core::ops::RangeInclusive) => {};
+    (core::future::Future) => {};
+    (core::ops::Try) => {};
     ($path:path) => {
         compile_error!("Please register your known path in the path module")
     };
diff --git a/crates/ra_hir_def/src/per_ns.rs b/crates/ra_hir_def/src/per_ns.rs
index 6e435c8c1..74665c588 100644
--- a/crates/ra_hir_def/src/per_ns.rs
+++ b/crates/ra_hir_def/src/per_ns.rs
@@ -5,7 +5,7 @@
 
 use hir_expand::MacroDefId;
 
-use crate::{visibility::Visibility, ModuleDefId};
+use crate::{item_scope::ItemInNs, visibility::Visibility, ModuleDefId};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct PerNs {
@@ -84,4 +84,12 @@ impl PerNs {
             macros: self.macros.or(other.macros),
         }
     }
+
+    pub fn iter_items(self) -> impl Iterator<Item = ItemInNs> {
+        self.types
+            .map(|it| ItemInNs::Types(it.0))
+            .into_iter()
+            .chain(self.values.map(|it| ItemInNs::Values(it.0)).into_iter())
+            .chain(self.macros.map(|it| ItemInNs::Macros(it.0)).into_iter())
+    }
 }
diff --git a/crates/ra_hir_def/src/test_db.rs b/crates/ra_hir_def/src/test_db.rs
index eb83dee79..4581d8745 100644
--- a/crates/ra_hir_def/src/test_db.rs
+++ b/crates/ra_hir_def/src/test_db.rs
@@ -6,9 +6,8 @@ use std::{
 };
 
 use hir_expand::db::AstDatabase;
-use ra_db::{
-    salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath, Upcast,
-};
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, Upcast};
+use rustc_hash::FxHashSet;
 
 use crate::db::DefDatabase;
 
@@ -58,24 +57,12 @@ impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-
-    fn resolve_extern_path(
-        &self,
-        extern_id: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl TestDB {
diff --git a/crates/ra_hir_expand/Cargo.toml b/crates/ra_hir_expand/Cargo.toml
index 2cd522766..e5c9f3e99 100644
--- a/crates/ra_hir_expand/Cargo.toml
+++ b/crates/ra_hir_expand/Cargo.toml
@@ -10,6 +10,7 @@ doctest = false
 [dependencies]
 log = "0.4.8"
 either = "1.5.3"
+rustc-hash = "1.0.0"
 
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs
index 1dc9cac66..26b667b55 100644
--- a/crates/ra_hir_expand/src/builtin_derive.rs
+++ b/crates/ra_hir_expand/src/builtin_derive.rs
@@ -8,8 +8,7 @@ use ra_syntax::{
     match_ast,
 };
 
-use crate::db::AstDatabase;
-use crate::{name, quote, LazyMacroId, MacroCallId, MacroDefId, MacroDefKind};
+use crate::{db::AstDatabase, name, quote, LazyMacroId, MacroDefId, MacroDefKind};
 
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
@@ -156,23 +155,13 @@ fn expand_simple_derive(
 fn find_builtin_crate(db: &dyn AstDatabase, id: LazyMacroId) -> tt::TokenTree {
     // FIXME: make hygiene works for builtin derive macro
     // such that $crate can be used here.
-
-    let m: MacroCallId = id.into();
-    let file_id = m.as_file().original_file(db);
     let cg = db.crate_graph();
-    let krates = db.relevant_crates(file_id);
-    let krate = match krates.get(0) {
-        Some(krate) => krate,
-        None => {
-            let tt = quote! { core };
-            return tt.token_trees[0].clone();
-        }
-    };
+    let krate = db.lookup_intern_macro(id).krate;
 
     // XXX
     //  All crates except core itself should have a dependency on core,
     //  We detect `core` by seeing whether it doesn't have such a dependency.
-    let tt = if cg[*krate].dependencies.iter().any(|dep| dep.name == "core") {
+    let tt = if cg[krate].dependencies.iter().any(|dep| dep.name == "core") {
         quote! { core }
     } else {
         quote! { crate }
@@ -264,10 +253,12 @@ fn partial_ord_expand(
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
     use name::{known, Name};
-    use ra_db::{fixture::WithFixture, SourceDatabase};
+    use ra_db::{fixture::WithFixture, CrateId, SourceDatabase};
+
+    use crate::{test_db::TestDB, AstId, MacroCallId, MacroCallKind, MacroCallLoc};
+
+    use super::*;
 
     fn expand_builtin_derive(s: &str, name: Name) -> String {
         let def = find_builtin_derive(&name).unwrap();
@@ -291,7 +282,11 @@ mod tests {
 
         let attr_id = AstId::new(file_id.into(), ast_id_map.ast_id(&items[0]));
 
-        let loc = MacroCallLoc { def, kind: MacroCallKind::Attr(attr_id, name.to_string()) };
+        let loc = MacroCallLoc {
+            def,
+            krate: CrateId(0),
+            kind: MacroCallKind::Attr(attr_id, name.to_string()),
+        };
 
         let id: MacroCallId = db.intern_macro(loc).into();
         let parsed = db.parse_or_expand(id.as_file()).unwrap();
diff --git a/crates/ra_hir_expand/src/builtin_macro.rs b/crates/ra_hir_expand/src/builtin_macro.rs
index 3bce8f673..b50eb347c 100644
--- a/crates/ra_hir_expand/src/builtin_macro.rs
+++ b/crates/ra_hir_expand/src/builtin_macro.rs
@@ -1,15 +1,14 @@
 //! Builtin macro
-use crate::db::AstDatabase;
 use crate::{
-    ast::{self, AstToken, HasStringValue},
-    name, AstId, CrateId, MacroDefId, MacroDefKind, TextSize,
+    db::AstDatabase, name, quote, AstId, CrateId, EagerMacroId, LazyMacroId, MacroCallId,
+    MacroDefId, MacroDefKind, TextSize,
 };
 
-use crate::{quote, EagerMacroId, LazyMacroId, MacroCallId};
 use either::Either;
 use mbe::parse_to_token_tree;
-use ra_db::{FileId, RelativePath};
+use ra_db::FileId;
 use ra_parser::FragmentKind;
+use ra_syntax::ast::{self, AstToken, HasStringValue};
 
 macro_rules! register_builtin {
     ( LAZY: $(($name:ident, $kind: ident) => $expand:ident),* , EAGER: $(($e_name:ident, $e_kind: ident) => $e_expand:ident),*  ) => {
@@ -295,19 +294,13 @@ fn concat_expand(
 
 fn relative_file(db: &dyn AstDatabase, call_id: MacroCallId, path: &str) -> Option<FileId> {
     let call_site = call_id.as_file().original_file(db);
-
-    // Handle trivial case
-    if let Some(res) = db.resolve_relative_path(call_site, &RelativePath::new(&path)) {
-        // Prevent include itself
-        return if res == call_site { None } else { Some(res) };
+    let res = db.resolve_path(call_site, path)?;
+    // Prevent include itself
+    if res == call_site {
+        None
+    } else {
+        Some(res)
     }
-
-    // Extern paths ?
-    let krate = *db.relevant_crates(call_site).get(0)?;
-    let (extern_source_id, relative_file) =
-        db.crate_graph()[krate].extern_source.extern_path(path)?;
-
-    db.resolve_extern_path(extern_source_id, &relative_file)
 }
 
 fn parse_string(tt: &tt::Subtree) -> Result<String, mbe::ExpandError> {
@@ -339,10 +332,7 @@ fn include_expand(
 }
 
 fn get_env_inner(db: &dyn AstDatabase, arg_id: EagerMacroId, key: &str) -> Option<String> {
-    let call_id: MacroCallId = arg_id.into();
-    let original_file = call_id.as_file().original_file(db);
-
-    let krate = *db.relevant_crates(original_file).get(0)?;
+    let krate = db.lookup_intern_eager_expansion(arg_id).krate;
     db.crate_graph()[krate].env.get(key)
 }
 
@@ -401,6 +391,7 @@ mod tests {
 
         let expander = find_by_name(&macro_calls[0].name().unwrap().as_name()).unwrap();
 
+        let krate = CrateId(0);
         let file_id = match expander {
             Either::Left(expander) => {
                 // the first one should be a macro_rules
@@ -413,6 +404,7 @@ mod tests {
 
                 let loc = MacroCallLoc {
                     def,
+                    krate,
                     kind: MacroCallKind::FnLike(AstId::new(
                         file_id.into(),
                         ast_id_map.ast_id(&macro_calls[1]),
@@ -425,7 +417,7 @@ mod tests {
             Either::Right(expander) => {
                 // the first one should be a macro_rules
                 let def = MacroDefId {
-                    krate: Some(CrateId(0)),
+                    krate: Some(krate),
                     ast_id: Some(AstId::new(file_id.into(), ast_id_map.ast_id(&macro_calls[0]))),
                     kind: MacroDefKind::BuiltInEager(expander),
                     local_inner: false,
@@ -439,6 +431,7 @@ mod tests {
                         def,
                         fragment: FragmentKind::Expr,
                         subtree: Arc::new(parsed_args.clone()),
+                        krate,
                         file_id: file_id.into(),
                     }
                 });
@@ -448,6 +441,7 @@ mod tests {
                     def,
                     fragment,
                     subtree: Arc::new(subtree),
+                    krate,
                     file_id: file_id.into(),
                 };
 
diff --git a/crates/ra_hir_expand/src/eager.rs b/crates/ra_hir_expand/src/eager.rs
index 932f47c30..302d2b3e0 100644
--- a/crates/ra_hir_expand/src/eager.rs
+++ b/crates/ra_hir_expand/src/eager.rs
@@ -25,12 +25,14 @@ use crate::{
     EagerCallLoc, EagerMacroId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
 };
 
+use ra_db::CrateId;
 use ra_parser::FragmentKind;
 use ra_syntax::{algo::SyntaxRewriter, SyntaxNode};
 use std::sync::Arc;
 
 pub fn expand_eager_macro(
     db: &dyn AstDatabase,
+    krate: CrateId,
     macro_call: InFile<ast::MacroCall>,
     def: MacroDefId,
     resolver: &dyn Fn(ast::Path) -> Option<MacroDefId>,
@@ -47,6 +49,7 @@ pub fn expand_eager_macro(
             def,
             fragment: FragmentKind::Expr,
             subtree: Arc::new(parsed_args.clone()),
+            krate,
             file_id: macro_call.file_id,
         }
     });
@@ -56,14 +59,20 @@ pub fn expand_eager_macro(
     let result = eager_macro_recur(
         db,
         InFile::new(arg_file_id.as_file(), parsed_args.syntax_node()),
+        krate,
         resolver,
     )?;
     let subtree = to_subtree(&result)?;
 
     if let MacroDefKind::BuiltInEager(eager) = def.kind {
         let (subtree, fragment) = eager.expand(db, arg_id, &subtree).ok()?;
-        let eager =
-            EagerCallLoc { def, fragment, subtree: Arc::new(subtree), file_id: macro_call.file_id };
+        let eager = EagerCallLoc {
+            def,
+            fragment,
+            subtree: Arc::new(subtree),
+            krate,
+            file_id: macro_call.file_id,
+        };
 
         Some(db.intern_eager_expansion(eager))
     } else {
@@ -81,11 +90,12 @@ fn lazy_expand(
     db: &dyn AstDatabase,
     def: &MacroDefId,
     macro_call: InFile<ast::MacroCall>,
+    krate: CrateId,
 ) -> Option<InFile<SyntaxNode>> {
     let ast_id = db.ast_id_map(macro_call.file_id).ast_id(&macro_call.value);
 
     let id: MacroCallId =
-        def.as_lazy_macro(db, MacroCallKind::FnLike(macro_call.with_value(ast_id))).into();
+        def.as_lazy_macro(db, krate, MacroCallKind::FnLike(macro_call.with_value(ast_id))).into();
 
     db.parse_or_expand(id.as_file()).map(|node| InFile::new(id.as_file(), node))
 }
@@ -93,6 +103,7 @@ fn lazy_expand(
 fn eager_macro_recur(
     db: &dyn AstDatabase,
     curr: InFile<SyntaxNode>,
+    krate: CrateId,
     macro_resolver: &dyn Fn(ast::Path) -> Option<MacroDefId>,
 ) -> Option<SyntaxNode> {
     let original = curr.value.clone();
@@ -105,18 +116,23 @@ fn eager_macro_recur(
         let def: MacroDefId = macro_resolver(child.path()?)?;
         let insert = match def.kind {
             MacroDefKind::BuiltInEager(_) => {
-                let id: MacroCallId =
-                    expand_eager_macro(db, curr.with_value(child.clone()), def, macro_resolver)?
-                        .into();
+                let id: MacroCallId = expand_eager_macro(
+                    db,
+                    krate,
+                    curr.with_value(child.clone()),
+                    def,
+                    macro_resolver,
+                )?
+                .into();
                 db.parse_or_expand(id.as_file())?
             }
             MacroDefKind::Declarative
             | MacroDefKind::BuiltIn(_)
             | MacroDefKind::BuiltInDerive(_)
             | MacroDefKind::CustomDerive(_) => {
-                let expanded = lazy_expand(db, &def, curr.with_value(child.clone()))?;
+                let expanded = lazy_expand(db, &def, curr.with_value(child.clone()), krate)?;
                 // replace macro inside
-                eager_macro_recur(db, expanded, macro_resolver)?
+                eager_macro_recur(db, expanded, krate, macro_resolver)?
             }
         };
 
diff --git a/crates/ra_hir_expand/src/lib.rs b/crates/ra_hir_expand/src/lib.rs
index f440c073b..5eac2605b 100644
--- a/crates/ra_hir_expand/src/lib.rs
+++ b/crates/ra_hir_expand/src/lib.rs
@@ -209,8 +209,13 @@ pub struct MacroDefId {
 }
 
 impl MacroDefId {
-    pub fn as_lazy_macro(self, db: &dyn db::AstDatabase, kind: MacroCallKind) -> LazyMacroId {
-        db.intern_macro(MacroCallLoc { def: self, kind })
+    pub fn as_lazy_macro(
+        self,
+        db: &dyn db::AstDatabase,
+        krate: CrateId,
+        kind: MacroCallKind,
+    ) -> LazyMacroId {
+        db.intern_macro(MacroCallLoc { def: self, krate, kind })
     }
 }
 
@@ -227,6 +232,7 @@ pub enum MacroDefKind {
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub(crate) def: MacroDefId,
+    pub(crate) krate: CrateId,
     pub(crate) kind: MacroCallKind,
 }
 
@@ -274,6 +280,7 @@ pub struct EagerCallLoc {
     pub(crate) def: MacroDefId,
     pub(crate) fragment: FragmentKind,
     pub(crate) subtree: Arc<tt::Subtree>,
+    pub(crate) krate: CrateId,
     pub(crate) file_id: HirFileId,
 }
 
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index ea495cb11..660bdfe33 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -153,6 +153,7 @@ pub mod known {
         str,
         // Special names
         macro_rules,
+        doc,
         // Components of known path (value or mod name)
         std,
         core,
diff --git a/crates/ra_hir_expand/src/test_db.rs b/crates/ra_hir_expand/src/test_db.rs
index c1fb762de..09fc18c36 100644
--- a/crates/ra_hir_expand/src/test_db.rs
+++ b/crates/ra_hir_expand/src/test_db.rs
@@ -5,7 +5,8 @@ use std::{
     sync::{Arc, Mutex},
 };
 
-use ra_db::{salsa, CrateId, ExternSourceId, FileId, FileLoader, FileLoaderDelegate, RelativePath};
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate};
+use rustc_hash::FxHashSet;
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
@@ -41,21 +42,10 @@ impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        anchor: ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(anchor, relative_path)
-    }
 }
diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 4b8dcdc07..112fcd07e 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -27,8 +27,8 @@ test_utils = { path = "../test_utils" }
 
 scoped-tls = "1"
 
-chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "329b7f3fdd2431ed6f6778cde53f22374c7d094c" }
-chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "329b7f3fdd2431ed6f6778cde53f22374c7d094c" }
+chalk-solve = "0.11"
+chalk-ir = "0.11"
 
 [dev-dependencies]
 insta = "0.16.0"
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 0a8bb24ac..bf71d38d6 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -3,8 +3,8 @@
 use std::sync::Arc;
 
 use hir_def::{
-    db::DefDatabase, DefWithBodyId, GenericDefId, ImplId, LocalFieldId, TraitId, TypeParamId,
-    VariantId,
+    db::DefDatabase, DefWithBodyId, FunctionId, GenericDefId, ImplId, LocalFieldId, TraitId,
+    TypeParamId, VariantId,
 };
 use ra_arena::map::ArenaMap;
 use ra_db::{impl_intern_key, salsa, CrateId, Upcast};
@@ -13,8 +13,8 @@ use ra_prof::profile;
 use crate::{
     method_resolution::{CrateImplDefs, TyFingerprint},
     traits::{chalk, AssocTyValue, Impl},
-    Binders, CallableDef, GenericPredicate, InferenceResult, PolyFnSig, Substs, TraitRef, Ty,
-    TyDefId, TypeCtor, ValueTyDefId,
+    Binders, CallableDef, GenericPredicate, InferenceResult, OpaqueTyId, PolyFnSig,
+    ReturnTypeImplTraits, Substs, TraitRef, Ty, TyDefId, TypeCtor, ValueTyDefId,
 };
 use hir_expand::name::Name;
 
@@ -48,6 +48,12 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     #[salsa::invoke(crate::callable_item_sig)]
     fn callable_item_signature(&self, def: CallableDef) -> PolyFnSig;
 
+    #[salsa::invoke(crate::lower::return_type_impl_traits)]
+    fn return_type_impl_traits(
+        &self,
+        def: FunctionId,
+    ) -> Option<Arc<Binders<ReturnTypeImplTraits>>>;
+
     #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
     #[salsa::cycle(crate::lower::generic_predicates_for_param_recover)]
     fn generic_predicates_for_param(
@@ -80,6 +86,8 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
     #[salsa::interned]
     fn intern_type_param_id(&self, param_id: TypeParamId) -> GlobalTypeParamId;
     #[salsa::interned]
+    fn intern_impl_trait_id(&self, id: OpaqueTyId) -> InternedOpaqueTyId;
+    #[salsa::interned]
     fn intern_chalk_impl(&self, impl_: Impl) -> crate::traits::GlobalImplId;
     #[salsa::interned]
     fn intern_assoc_ty_value(&self, assoc_ty_value: AssocTyValue) -> crate::traits::AssocTyValueId;
@@ -142,3 +150,7 @@ fn hir_database_is_object_safe() {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct GlobalTypeParamId(salsa::InternId);
 impl_intern_key!(GlobalTypeParamId);
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct InternedOpaqueTyId(salsa::InternId);
+impl_intern_key!(InternedOpaqueTyId);
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index b9c4d2e89..3c97e1354 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -4,7 +4,7 @@ use std::fmt;
 
 use crate::{
     db::HirDatabase, utils::generics, ApplicationTy, CallableDef, FnSig, GenericPredicate,
-    Obligation, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
+    Obligation, OpaqueTyId, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
 };
 use hir_def::{
     find_path, generics::TypeParamProvenance, item_scope::ItemInNs, AdtId, AssocContainerId,
@@ -359,6 +359,21 @@ impl HirDisplay for ApplicationTy {
                     write!(f, ">")?;
                 }
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => {
+                let bounds = match opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                        let datas =
+                            f.db.return_type_impl_traits(func).expect("impl trait id without data");
+                        let data = (*datas)
+                            .as_ref()
+                            .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                        data.clone().subst(&self.parameters)
+                    }
+                };
+                write!(f, "impl ")?;
+                write_bounds_like_dyn_trait(&bounds.value, f)?;
+                // FIXME: it would maybe be good to distinguish this from the alias type (when debug printing), and to show the substitution
+            }
             TypeCtor::Closure { .. } => {
                 let sig = self.parameters[0].callable_sig(f.db);
                 if let Some(sig) = sig {
@@ -427,14 +442,24 @@ impl HirDisplay for Ty {
                 }
             }
             Ty::Bound(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
-                match self {
-                    Ty::Dyn(_) => write!(f, "dyn ")?,
-                    Ty::Opaque(_) => write!(f, "impl ")?,
-                    _ => unreachable!(),
-                };
+            Ty::Dyn(predicates) => {
+                write!(f, "dyn ")?;
                 write_bounds_like_dyn_trait(predicates, f)?;
             }
+            Ty::Opaque(opaque_ty) => {
+                let bounds = match opaque_ty.opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                        let datas =
+                            f.db.return_type_impl_traits(func).expect("impl trait id without data");
+                        let data = (*datas)
+                            .as_ref()
+                            .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                        data.clone().subst(&opaque_ty.parameters)
+                    }
+                };
+                write!(f, "impl ")?;
+                write_bounds_like_dyn_trait(&bounds.value, f)?;
+            }
             Ty::Unknown => write!(f, "{{unknown}}")?,
             Ty::Infer(..) => write!(f, "_")?,
         }
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index f04968e14..7db928dde 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -226,17 +226,19 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             None => return,
         };
 
-        let std_result_path = path![std::result::Result];
+        let core_result_path = path![core::result::Result];
 
         let resolver = self.func.resolver(db.upcast());
-        let std_result_enum = match resolver.resolve_known_enum(db.upcast(), &std_result_path) {
+        let core_result_enum = match resolver.resolve_known_enum(db.upcast(), &core_result_path) {
             Some(it) => it,
             _ => return,
         };
 
-        let std_result_ctor = TypeCtor::Adt(AdtId::EnumId(std_result_enum));
+        let core_result_ctor = TypeCtor::Adt(AdtId::EnumId(core_result_enum));
         let params = match &mismatch.expected {
-            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &std_result_ctor => parameters,
+            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_result_ctor => {
+                parameters
+            }
             _ => return,
         };
 
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index dc77e88e5..3719f76a6 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -39,8 +39,7 @@ use ra_syntax::SmolStr;
 use super::{
     primitive::{FloatTy, IntTy},
     traits::{Guidance, Obligation, ProjectionPredicate, Solution},
-    ApplicationTy, GenericPredicate, InEnvironment, ProjectionTy, Substs, TraitEnvironment,
-    TraitRef, Ty, TypeCtor, TypeWalk, Uncertain,
+    InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 use crate::{
     db::HirDatabase, infer::diagnostics::InferenceDiagnostic, lower::ImplTraitLoweringMode,
@@ -312,12 +311,6 @@ impl<'a> InferenceContext<'a> {
     fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
         match ty {
             Ty::Unknown => self.table.new_type_var(),
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(Uncertain::Unknown), .. }) => {
-                self.table.new_integer_var()
-            }
-            Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(Uncertain::Unknown), .. }) => {
-                self.table.new_float_var()
-            }
             _ => ty,
         }
     }
@@ -383,25 +376,6 @@ impl<'a> InferenceContext<'a> {
     ) -> Ty {
         match assoc_ty {
             Some(res_assoc_ty) => {
-                // FIXME:
-                // Check if inner_ty is is `impl Trait` and contained input TypeAlias id
-                // this is a workaround while Chalk assoc type projection doesn't always work yet,
-                // but once that is fixed I don't think we should keep this
-                // (we'll probably change how associated types are resolved anyway)
-                if let Ty::Opaque(ref predicates) = inner_ty {
-                    for p in predicates.iter() {
-                        if let GenericPredicate::Projection(projection) = p {
-                            if projection.projection_ty.associated_ty == res_assoc_ty {
-                                if let ty_app!(_, params) = &projection.ty {
-                                    if params.len() == 0 {
-                                        return projection.ty.clone();
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-
                 let ty = self.table.new_type_var();
                 let builder = Substs::build_for_def(self.db, res_assoc_ty)
                     .push(inner_ty)
@@ -458,13 +432,13 @@ impl<'a> InferenceContext<'a> {
             };
         return match resolution {
             TypeNs::AdtId(AdtId::StructId(strukt)) => {
-                let substs = Ty::substs_from_path(&ctx, path, strukt.into());
+                let substs = Ty::substs_from_path(&ctx, path, strukt.into(), true);
                 let ty = self.db.ty(strukt.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
                 forbid_unresolved_segments((ty, Some(strukt.into())), unresolved)
             }
             TypeNs::EnumVariantId(var) => {
-                let substs = Ty::substs_from_path(&ctx, path, var.into());
+                let substs = Ty::substs_from_path(&ctx, path, var.into(), true);
                 let ty = self.db.ty(var.parent.into());
                 let ty = self.insert_type_vars(ty.subst(&substs));
                 forbid_unresolved_segments((ty, Some(var.into())), unresolved)
@@ -581,13 +555,13 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
-        let path = path![std::iter::IntoIterator];
+        let path = path![core::iter::IntoIterator];
         let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
         self.db.trait_data(trait_).associated_type_by_name(&name![Item])
     }
 
     fn resolve_ops_try_ok(&self) -> Option<TypeAliasId> {
-        let path = path![std::ops::Try];
+        let path = path![core::ops::Try];
         let trait_ = self.resolver.resolve_known_trait(self.db.upcast(), &path)?;
         self.db.trait_data(trait_).associated_type_by_name(&name![Ok])
     }
@@ -613,37 +587,37 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn resolve_range_full(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeFull];
+        let path = path![core::ops::RangeFull];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range(&self) -> Option<AdtId> {
-        let path = path![std::ops::Range];
+        let path = path![core::ops::Range];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_inclusive(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeInclusive];
+        let path = path![core::ops::RangeInclusive];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_from(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeFrom];
+        let path = path![core::ops::RangeFrom];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_to(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeTo];
+        let path = path![core::ops::RangeTo];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
 
     fn resolve_range_to_inclusive(&self) -> Option<AdtId> {
-        let path = path![std::ops::RangeToInclusive];
+        let path = path![core::ops::RangeToInclusive];
         let struct_ = self.resolver.resolve_known_struct(self.db.upcast(), &path)?;
         Some(struct_.into())
     }
@@ -683,8 +657,8 @@ impl InferTy {
     fn fallback_value(self) -> Ty {
         match self {
             InferTy::TypeVar(..) => Ty::Unknown,
-            InferTy::IntVar(..) => Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::i32()))),
-            InferTy::FloatVar(..) => Ty::simple(TypeCtor::Float(Uncertain::Known(FloatTy::f64()))),
+            InferTy::IntVar(..) => Ty::simple(TypeCtor::Int(IntTy::i32())),
+            InferTy::FloatVar(..) => Ty::simple(TypeCtor::Float(FloatTy::f64())),
             InferTy::MaybeNeverTypeVar(..) => Ty::simple(TypeCtor::Never),
         }
     }
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 4a98e2deb..9fd310f69 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -18,7 +18,7 @@ use crate::{
     traits::InEnvironment,
     utils::{generics, variant_data, Generics},
     ApplicationTy, Binders, CallableDef, InferTy, IntTy, Mutability, Obligation, Rawness, Substs,
-    TraitRef, Ty, TypeCtor, Uncertain,
+    TraitRef, Ty, TypeCtor,
 };
 
 use super::{
@@ -426,15 +426,7 @@ impl<'a> InferenceContext<'a> {
                         match &inner_ty {
                             // Fast path for builtins
                             Ty::Apply(ApplicationTy {
-                                ctor:
-                                    TypeCtor::Int(Uncertain::Known(IntTy {
-                                        signedness: Signedness::Signed,
-                                        ..
-                                    })),
-                                ..
-                            })
-                            | Ty::Apply(ApplicationTy {
-                                ctor: TypeCtor::Int(Uncertain::Unknown),
+                                ctor: TypeCtor::Int(IntTy { signedness: Signedness::Signed, .. }),
                                 ..
                             })
                             | Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(_), .. })
@@ -577,9 +569,7 @@ impl<'a> InferenceContext<'a> {
                         );
                         self.infer_expr(
                             *repeat,
-                            &Expectation::has_type(Ty::simple(TypeCtor::Int(Uncertain::Known(
-                                IntTy::usize(),
-                            )))),
+                            &Expectation::has_type(Ty::simple(TypeCtor::Int(IntTy::usize()))),
                         );
                     }
                 }
@@ -592,13 +582,19 @@ impl<'a> InferenceContext<'a> {
                     Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str))
                 }
                 Literal::ByteString(..) => {
-                    let byte_type = Ty::simple(TypeCtor::Int(Uncertain::Known(IntTy::u8())));
+                    let byte_type = Ty::simple(TypeCtor::Int(IntTy::u8()));
                     let array_type = Ty::apply_one(TypeCtor::Array, byte_type);
                     Ty::apply_one(TypeCtor::Ref(Mutability::Shared), array_type)
                 }
                 Literal::Char(..) => Ty::simple(TypeCtor::Char),
-                Literal::Int(_v, ty) => Ty::simple(TypeCtor::Int((*ty).into())),
-                Literal::Float(_v, ty) => Ty::simple(TypeCtor::Float((*ty).into())),
+                Literal::Int(_v, ty) => match ty {
+                    Some(int_ty) => Ty::simple(TypeCtor::Int((*int_ty).into())),
+                    None => self.table.new_integer_var(),
+                },
+                Literal::Float(_v, ty) => match ty {
+                    Some(float_ty) => Ty::simple(TypeCtor::Float((*float_ty).into())),
+                    None => self.table.new_float_var(),
+                },
             },
         };
         // use a new type variable if we got Ty::Unknown here
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 1c2e56fb0..1ad0d8397 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -95,7 +95,7 @@ impl<'a> InferenceContext<'a> {
         // self_subst is just for the parent
         let parent_substs = self_subst.unwrap_or_else(Substs::empty);
         let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver);
-        let substs = Ty::substs_from_path(&ctx, path, typable);
+        let substs = Ty::substs_from_path(&ctx, path, typable, true);
         let full_substs = Substs::builder(substs.len())
             .use_parent_substs(&parent_substs)
             .fill(substs.0[parent_substs.len()..].iter().cloned())
@@ -141,6 +141,7 @@ impl<'a> InferenceContext<'a> {
                     def,
                     resolved_segment,
                     remaining_segments_for_ty,
+                    true,
                 );
                 if let Ty::Unknown = ty {
                     return None;
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 9fa8d3bdc..2b9372b4b 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -58,7 +58,7 @@ use ra_db::{impl_intern_key, salsa, CrateId};
 
 use crate::{
     db::HirDatabase,
-    primitive::{FloatTy, IntTy, Uncertain},
+    primitive::{FloatTy, IntTy},
     utils::{generics, make_mut_slice, Generics},
 };
 use display::HirDisplay;
@@ -87,10 +87,10 @@ pub enum TypeCtor {
     Char,
 
     /// A primitive integer type. For example, `i32`.
-    Int(Uncertain<IntTy>),
+    Int(IntTy),
 
     /// A primitive floating-point type. For example, `f64`.
-    Float(Uncertain<FloatTy>),
+    Float(FloatTy),
 
     /// Structures, enumerations and unions.
     Adt(AdtId),
@@ -147,6 +147,12 @@ pub enum TypeCtor {
     /// an **application type** like `(Iterator::Item)<T>`.
     AssociatedType(TypeAliasId),
 
+    /// This represents a placeholder for an opaque type in situations where we
+    /// don't know the hidden type (i.e. currently almost always). This is
+    /// analogous to the `AssociatedType` type constructor. As with that one,
+    /// these are only produced by Chalk.
+    OpaqueType(OpaqueTyId),
+
     /// The type of a specific closure.
     ///
     /// The closure signature is stored in a `FnPtr` type in the first type
@@ -194,6 +200,14 @@ impl TypeCtor {
                 let generic_params = generics(db.upcast(), type_alias.into());
                 generic_params.len()
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => {
+                match opaque_ty_id {
+                    OpaqueTyId::ReturnTypeImplTrait(func, _) => {
+                        let generic_params = generics(db.upcast(), func.into());
+                        generic_params.len()
+                    }
+                }
+            }
             TypeCtor::FnPtr { num_args } => num_args as usize + 1,
             TypeCtor::Tuple { cardinality } => cardinality as usize,
         }
@@ -220,6 +234,11 @@ impl TypeCtor {
             TypeCtor::AssociatedType(type_alias) => {
                 Some(type_alias.lookup(db.upcast()).module(db.upcast()).krate)
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => match opaque_ty_id {
+                OpaqueTyId::ReturnTypeImplTrait(func, _) => {
+                    Some(func.lookup(db.upcast()).module(db.upcast()).krate)
+                }
+            },
         }
     }
 
@@ -241,6 +260,7 @@ impl TypeCtor {
             TypeCtor::Adt(adt) => Some(adt.into()),
             TypeCtor::FnDef(callable) => Some(callable.into()),
             TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
+            TypeCtor::OpaqueType(_impl_trait_id) => None,
         }
     }
 }
@@ -254,6 +274,12 @@ pub struct ApplicationTy {
     pub parameters: Substs,
 }
 
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct OpaqueTy {
+    pub opaque_ty_id: OpaqueTyId,
+    pub parameters: Substs,
+}
+
 /// A "projection" type corresponds to an (unnormalized)
 /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
 /// trait and all its parameters are fully known.
@@ -308,6 +334,12 @@ pub enum Ty {
     /// trait and all its parameters are fully known.
     Projection(ProjectionTy),
 
+    /// An opaque type (`impl Trait`).
+    ///
+    /// This is currently only used for return type impl trait; each instance of
+    /// `impl Trait` in a return type gets its own ID.
+    Opaque(OpaqueTy),
+
     /// A placeholder for a type parameter; for example, `T` in `fn f<T>(x: T)
     /// {}` when we're type-checking the body of that function. In this
     /// situation, we know this stands for *some* type, but don't know the exact
@@ -332,12 +364,6 @@ pub enum Ty {
     /// didn't seem worth the overhead yet.
     Dyn(Arc<[GenericPredicate]>),
 
-    /// An opaque type (`impl Trait`).
-    ///
-    /// The predicates are quantified over the `Self` type; see `Ty::Dyn` for
-    /// more.
-    Opaque(Arc<[GenericPredicate]>),
-
     /// A placeholder for a type which could not be computed; this is propagated
     /// to avoid useless error messages. Doubles as a placeholder where type
     /// variables are inserted before type checking, since we want to try to
@@ -490,7 +516,7 @@ impl Deref for Substs {
     }
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 pub struct Binders<T> {
     pub num_binders: usize,
     pub value: T,
@@ -534,6 +560,20 @@ impl<T: TypeWalk> Binders<T> {
     }
 }
 
+impl<T: TypeWalk> TypeWalk for Binders<T> {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        self.value.walk(f);
+    }
+
+    fn walk_mut_binders(
+        &mut self,
+        f: &mut impl FnMut(&mut Ty, DebruijnIndex),
+        binders: DebruijnIndex,
+    ) {
+        self.value.walk_mut_binders(f, binders.shifted_in())
+    }
+}
+
 /// A trait with type parameters. This includes the `Self`, so this represents a concrete type implementing the trait.
 /// Name to be bikeshedded: TraitBound? TraitImplements?
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -947,11 +987,16 @@ impl TypeWalk for Ty {
                     t.walk(f);
                 }
             }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+            Ty::Dyn(predicates) => {
                 for p in predicates.iter() {
                     p.walk(f);
                 }
             }
+            Ty::Opaque(o_ty) => {
+                for t in o_ty.parameters.iter() {
+                    t.walk(f);
+                }
+            }
             Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self);
@@ -969,13 +1014,48 @@ impl TypeWalk for Ty {
             Ty::Projection(p_ty) => {
                 p_ty.parameters.walk_mut_binders(f, binders);
             }
-            Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
+            Ty::Dyn(predicates) => {
                 for p in make_mut_slice(predicates) {
                     p.walk_mut_binders(f, binders.shifted_in());
                 }
             }
+            Ty::Opaque(o_ty) => {
+                o_ty.parameters.walk_mut_binders(f, binders);
+            }
             Ty::Placeholder { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
         }
         f(self, binders);
     }
 }
+
+impl<T: TypeWalk> TypeWalk for Vec<T> {
+    fn walk(&self, f: &mut impl FnMut(&Ty)) {
+        for t in self {
+            t.walk(f);
+        }
+    }
+    fn walk_mut_binders(
+        &mut self,
+        f: &mut impl FnMut(&mut Ty, DebruijnIndex),
+        binders: DebruijnIndex,
+    ) {
+        for t in self {
+            t.walk_mut_binders(f, binders);
+        }
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
+pub enum OpaqueTyId {
+    ReturnTypeImplTrait(hir_def::FunctionId, u16),
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct ReturnTypeImplTraits {
+    pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub(crate) struct ReturnTypeImplTrait {
+    pub(crate) bounds: Binders<Vec<GenericPredicate>>,
+}
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 35ac86a46..42713928f 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -21,8 +21,10 @@ use hir_def::{
     HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
     UnionId, VariantId,
 };
+use hir_expand::name::Name;
 use ra_arena::map::ArenaMap;
 use ra_db::CrateId;
+use test_utils::mark;
 
 use crate::{
     db::HirDatabase,
@@ -31,10 +33,10 @@ use crate::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
         make_mut_slice, variant_data,
     },
-    Binders, BoundVar, DebruijnIndex, FnSig, GenericPredicate, PolyFnSig, ProjectionPredicate,
-    ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
+    Binders, BoundVar, DebruijnIndex, FnSig, GenericPredicate, OpaqueTy, OpaqueTyId, PolyFnSig,
+    ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait, ReturnTypeImplTraits, Substs,
+    TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
-use hir_expand::name::Name;
 
 #[derive(Debug)]
 pub struct TyLoweringContext<'a> {
@@ -47,7 +49,16 @@ pub struct TyLoweringContext<'a> {
     /// possible currently, so this should be fine for now.
     pub type_param_mode: TypeParamLoweringMode,
     pub impl_trait_mode: ImplTraitLoweringMode,
-    pub impl_trait_counter: std::cell::Cell<u16>,
+    impl_trait_counter: std::cell::Cell<u16>,
+    /// When turning `impl Trait` into opaque types, we have to collect the
+    /// bounds at the same time to get the IDs correct (without becoming too
+    /// complicated). I don't like using interior mutability (as for the
+    /// counter), but I've tried and failed to make the lifetimes work for
+    /// passing around a `&mut TyLoweringContext`. The core problem is that
+    /// we're grouping the mutable data (the counter and this field) together
+    /// with the immutable context (the references to the DB and resolver).
+    /// Splitting this up would be a possible fix.
+    opaque_type_data: std::cell::RefCell<Vec<ReturnTypeImplTrait>>,
 }
 
 impl<'a> TyLoweringContext<'a> {
@@ -56,26 +67,42 @@ impl<'a> TyLoweringContext<'a> {
         let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
         let type_param_mode = TypeParamLoweringMode::Placeholder;
         let in_binders = DebruijnIndex::INNERMOST;
-        Self { db, resolver, in_binders, impl_trait_mode, impl_trait_counter, type_param_mode }
+        let opaque_type_data = std::cell::RefCell::new(Vec::new());
+        Self {
+            db,
+            resolver,
+            in_binders,
+            impl_trait_mode,
+            impl_trait_counter,
+            type_param_mode,
+            opaque_type_data,
+        }
     }
 
-    pub fn with_shifted_in<T>(
+    pub fn with_debruijn<T>(
         &self,
         debruijn: DebruijnIndex,
         f: impl FnOnce(&TyLoweringContext) -> T,
     ) -> T {
+        let opaque_ty_data_vec = self.opaque_type_data.replace(Vec::new());
         let new_ctx = Self {
-            in_binders: self.in_binders.shifted_in_from(debruijn),
+            in_binders: debruijn,
             impl_trait_counter: std::cell::Cell::new(self.impl_trait_counter.get()),
+            opaque_type_data: std::cell::RefCell::new(opaque_ty_data_vec),
             ..*self
         };
         let result = f(&new_ctx);
         self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
+        self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
         result
     }
 
-    pub fn shifted_in(self, debruijn: DebruijnIndex) -> Self {
-        Self { in_binders: self.in_binders.shifted_in_from(debruijn), ..self }
+    pub fn with_shifted_in<T>(
+        &self,
+        debruijn: DebruijnIndex,
+        f: impl FnOnce(&TyLoweringContext) -> T,
+    ) -> T {
+        self.with_debruijn(self.in_binders.shifted_in_from(debruijn), f)
     }
 
     pub fn with_impl_trait_mode(self, impl_trait_mode: ImplTraitLoweringMode) -> Self {
@@ -167,20 +194,44 @@ impl Ty {
             TypeRef::ImplTrait(bounds) => {
                 match ctx.impl_trait_mode {
                     ImplTraitLoweringMode::Opaque => {
-                        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
-                        let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
-                            bounds
-                                .iter()
-                                .flat_map(|b| {
-                                    GenericPredicate::from_type_bound(ctx, b, self_ty.clone())
-                                })
-                                .collect()
-                        });
-                        Ty::Opaque(predicates)
+                        let idx = ctx.impl_trait_counter.get();
+                        ctx.impl_trait_counter.set(idx + 1);
+
+                        assert!(idx as usize == ctx.opaque_type_data.borrow().len());
+                        // this dance is to make sure the data is in the right
+                        // place even if we encounter more opaque types while
+                        // lowering the bounds
+                        ctx.opaque_type_data
+                            .borrow_mut()
+                            .push(ReturnTypeImplTrait { bounds: Binders::new(1, Vec::new()) });
+                        // We don't want to lower the bounds inside the binders
+                        // we're currently in, because they don't end up inside
+                        // those binders. E.g. when we have `impl Trait<impl
+                        // OtherTrait<T>>`, the `impl OtherTrait<T>` can't refer
+                        // to the self parameter from `impl Trait`, and the
+                        // bounds aren't actually stored nested within each
+                        // other, but separately. So if the `T` refers to a type
+                        // parameter of the outer function, it's just one binder
+                        // away instead of two.
+                        let actual_opaque_type_data = ctx
+                            .with_debruijn(DebruijnIndex::INNERMOST, |ctx| {
+                                ReturnTypeImplTrait::from_hir(ctx, &bounds)
+                            });
+                        ctx.opaque_type_data.borrow_mut()[idx as usize] = actual_opaque_type_data;
+
+                        let func = match ctx.resolver.generic_def() {
+                            Some(GenericDefId::FunctionId(f)) => f,
+                            _ => panic!("opaque impl trait lowering in non-function"),
+                        };
+                        let impl_trait_id = OpaqueTyId::ReturnTypeImplTrait(func, idx);
+                        let generics = generics(ctx.db.upcast(), func.into());
+                        let parameters = Substs::bound_vars(&generics, ctx.in_binders);
+                        Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
                     }
                     ImplTraitLoweringMode::Param => {
                         let idx = ctx.impl_trait_counter.get();
-                        ctx.impl_trait_counter.set(idx + 1);
+                        // FIXME we're probably doing something wrong here
+                        ctx.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
                         if let Some(def) = ctx.resolver.generic_def() {
                             let generics = generics(ctx.db.upcast(), def);
                             let param = generics
@@ -197,7 +248,8 @@ impl Ty {
                     }
                     ImplTraitLoweringMode::Variable => {
                         let idx = ctx.impl_trait_counter.get();
-                        ctx.impl_trait_counter.set(idx + 1);
+                        // FIXME we're probably doing something wrong here
+                        ctx.impl_trait_counter.set(idx + count_impl_traits(type_ref) as u16);
                         let (parent_params, self_params, list_params, _impl_trait_params) =
                             if let Some(def) = ctx.resolver.generic_def() {
                                 let generics = generics(ctx.db.upcast(), def);
@@ -271,6 +323,7 @@ impl Ty {
         resolution: TypeNs,
         resolved_segment: PathSegment<'_>,
         remaining_segments: PathSegments<'_>,
+        infer_args: bool,
     ) -> (Ty, Option<TypeNs>) {
         let ty = match resolution {
             TypeNs::TraitId(trait_) => {
@@ -348,9 +401,15 @@ impl Ty {
                 ctx.db.ty(adt.into()).subst(&substs)
             }
 
-            TypeNs::AdtId(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
-            TypeNs::BuiltinType(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
-            TypeNs::TypeAliasId(it) => Ty::from_hir_path_inner(ctx, resolved_segment, it.into()),
+            TypeNs::AdtId(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
+            TypeNs::BuiltinType(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
+            TypeNs::TypeAliasId(it) => {
+                Ty::from_hir_path_inner(ctx, resolved_segment, it.into(), infer_args)
+            }
             // FIXME: report error
             TypeNs::EnumVariantId(_) => return (Ty::Unknown, None),
         };
@@ -376,7 +435,13 @@ impl Ty {
             ),
             Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
         };
-        Ty::from_partly_resolved_hir_path(ctx, resolution, resolved_segment, remaining_segments)
+        Ty::from_partly_resolved_hir_path(
+            ctx,
+            resolution,
+            resolved_segment,
+            remaining_segments,
+            false,
+        )
     }
 
     fn select_associated_type(
@@ -422,13 +487,14 @@ impl Ty {
         ctx: &TyLoweringContext<'_>,
         segment: PathSegment<'_>,
         typable: TyDefId,
+        infer_args: bool,
     ) -> Ty {
         let generic_def = match typable {
             TyDefId::BuiltinType(_) => None,
             TyDefId::AdtId(it) => Some(it.into()),
             TyDefId::TypeAliasId(it) => Some(it.into()),
         };
-        let substs = substs_from_path_segment(ctx, segment, generic_def, false);
+        let substs = substs_from_path_segment(ctx, segment, generic_def, infer_args);
         ctx.db.ty(typable).subst(&substs)
     }
 
@@ -441,6 +507,7 @@ impl Ty {
         // `ValueTyDefId` is just a convenient way to pass generics and
         // special-case enum variants
         resolved: ValueTyDefId,
+        infer_args: bool,
     ) -> Substs {
         let last = path.segments().last().expect("path should have at least one segment");
         let (segment, generic_def) = match resolved {
@@ -463,22 +530,27 @@ impl Ty {
                 (segment, Some(var.parent.into()))
             }
         };
-        substs_from_path_segment(ctx, segment, generic_def, false)
+        substs_from_path_segment(ctx, segment, generic_def, infer_args)
     }
 }
 
-pub(super) fn substs_from_path_segment(
+fn substs_from_path_segment(
     ctx: &TyLoweringContext<'_>,
     segment: PathSegment<'_>,
     def_generic: Option<GenericDefId>,
-    _add_self_param: bool,
+    infer_args: bool,
 ) -> Substs {
     let mut substs = Vec::new();
     let def_generics = def_generic.map(|def| generics(ctx.db.upcast(), def));
 
     let (parent_params, self_params, type_params, impl_trait_params) =
         def_generics.map_or((0, 0, 0, 0), |g| g.provenance_split());
+    let total_len = parent_params + self_params + type_params + impl_trait_params;
+
     substs.extend(iter::repeat(Ty::Unknown).take(parent_params));
+
+    let mut had_explicit_args = false;
+
     if let Some(generic_args) = &segment.args_and_bindings {
         if !generic_args.has_self_type {
             substs.extend(iter::repeat(Ty::Unknown).take(self_params));
@@ -490,31 +562,35 @@ pub(super) fn substs_from_path_segment(
         for arg in generic_args.args.iter().skip(skip).take(expected_num) {
             match arg {
                 GenericArg::Type(type_ref) => {
+                    had_explicit_args = true;
                     let ty = Ty::from_hir(ctx, type_ref);
                     substs.push(ty);
                 }
             }
         }
     }
-    let total_len = parent_params + self_params + type_params + impl_trait_params;
-    // add placeholders for args that were not provided
-    for _ in substs.len()..total_len {
-        substs.push(Ty::Unknown);
-    }
-    assert_eq!(substs.len(), total_len);
 
-    // handle defaults
-    if let Some(def_generic) = def_generic {
-        let default_substs = ctx.db.generic_defaults(def_generic);
-        assert_eq!(substs.len(), default_substs.len());
+    // handle defaults. In expression or pattern path segments without
+    // explicitly specified type arguments, missing type arguments are inferred
+    // (i.e. defaults aren't used).
+    if !infer_args || had_explicit_args {
+        if let Some(def_generic) = def_generic {
+            let default_substs = ctx.db.generic_defaults(def_generic);
+            assert_eq!(total_len, default_substs.len());
 
-        for (i, default_ty) in default_substs.iter().enumerate() {
-            if substs[i] == Ty::Unknown {
-                substs[i] = default_ty.clone();
+            for default_ty in default_substs.iter().skip(substs.len()) {
+                substs.push(default_ty.clone());
             }
         }
     }
 
+    // add placeholders for args that were not provided
+    // FIXME: emit diagnostics in contexts where this is not allowed
+    for _ in substs.len()..total_len {
+        substs.push(Ty::Unknown);
+    }
+    assert_eq!(substs.len(), total_len);
+
     Substs(substs.into())
 }
 
@@ -563,9 +639,7 @@ impl TraitRef {
         segment: PathSegment<'_>,
         resolved: TraitId,
     ) -> Substs {
-        let has_self_param =
-            segment.args_and_bindings.as_ref().map(|a| a.has_self_type).unwrap_or(false);
-        substs_from_path_segment(ctx, segment, Some(resolved.into()), !has_self_param)
+        substs_from_path_segment(ctx, segment, Some(resolved.into()), false)
     }
 
     pub(crate) fn from_type_bound(
@@ -663,6 +737,30 @@ fn assoc_type_bindings_from_type_bound<'a>(
         })
 }
 
+impl ReturnTypeImplTrait {
+    fn from_hir(ctx: &TyLoweringContext, bounds: &[TypeBound]) -> Self {
+        mark::hit!(lower_rpit);
+        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+        let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
+            bounds
+                .iter()
+                .flat_map(|b| GenericPredicate::from_type_bound(ctx, b, self_ty.clone()))
+                .collect()
+        });
+        ReturnTypeImplTrait { bounds: Binders::new(1, predicates) }
+    }
+}
+
+fn count_impl_traits(type_ref: &TypeRef) -> usize {
+    let mut count = 0;
+    type_ref.walk(&mut |type_ref| {
+        if matches!(type_ref, TypeRef::ImplTrait(_)) {
+            count += 1;
+        }
+    });
+    count
+}
+
 /// Build the signature of a callable item (function, struct or enum variant).
 pub fn callable_item_sig(db: &dyn HirDatabase, def: CallableDef) -> PolyFnSig {
     match def {
@@ -864,7 +962,9 @@ fn fn_sig_for_fn(db: &dyn HirDatabase, def: FunctionId) -> PolyFnSig {
         .with_impl_trait_mode(ImplTraitLoweringMode::Variable)
         .with_type_param_mode(TypeParamLoweringMode::Variable);
     let params = data.params.iter().map(|tr| Ty::from_hir(&ctx_params, tr)).collect::<Vec<_>>();
-    let ctx_ret = ctx_params.with_impl_trait_mode(ImplTraitLoweringMode::Opaque);
+    let ctx_ret = TyLoweringContext::new(db, &resolver)
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
+        .with_type_param_mode(TypeParamLoweringMode::Variable);
     let ret = Ty::from_hir(&ctx_ret, &data.ret_type);
     let generics = generics(db.upcast(), def.into());
     let num_binders = generics.len();
@@ -1084,3 +1184,25 @@ pub(crate) fn impl_trait_query(db: &dyn HirDatabase, impl_id: ImplId) -> Option<
         TraitRef::from_hir(&ctx, target_trait, Some(self_ty.value))?,
     ))
 }
+
+pub(crate) fn return_type_impl_traits(
+    db: &impl HirDatabase,
+    def: hir_def::FunctionId,
+) -> Option<Arc<Binders<ReturnTypeImplTraits>>> {
+    // FIXME unify with fn_sig_for_fn instead of doing lowering twice, maybe
+    let data = db.function_data(def);
+    let resolver = def.resolver(db.upcast());
+    let ctx_ret = TyLoweringContext::new(db, &resolver)
+        .with_impl_trait_mode(ImplTraitLoweringMode::Opaque)
+        .with_type_param_mode(TypeParamLoweringMode::Variable);
+    let _ret = Ty::from_hir(&ctx_ret, &data.ret_type);
+    let generics = generics(db.upcast(), def.into());
+    let num_binders = generics.len();
+    let return_type_impl_traits =
+        ReturnTypeImplTraits { impl_traits: ctx_ret.opaque_type_data.into_inner() };
+    if return_type_impl_traits.impl_traits.is_empty() {
+        None
+    } else {
+        Some(Arc::new(Binders::new(num_binders, return_type_impl_traits)))
+    }
+}
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index e19628fdf..e83b39456 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -16,12 +16,8 @@ use rustc_hash::{FxHashMap, FxHashSet};
 
 use super::Substs;
 use crate::{
-    autoderef,
-    db::HirDatabase,
-    primitive::{FloatBitness, Uncertain},
-    utils::all_super_traits,
-    ApplicationTy, Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty,
-    TypeCtor, TypeWalk,
+    autoderef, db::HirDatabase, primitive::FloatBitness, utils::all_super_traits, ApplicationTy,
+    Canonical, DebruijnIndex, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 /// This is used as a key for indexing impls.
@@ -147,12 +143,12 @@ impl Ty {
                 }
                 TypeCtor::Bool => lang_item_crate!("bool"),
                 TypeCtor::Char => lang_item_crate!("char"),
-                TypeCtor::Float(Uncertain::Known(f)) => match f.bitness {
+                TypeCtor::Float(f) => match f.bitness {
                     // There are two lang items: one in libcore (fXX) and one in libstd (fXX_runtime)
                     FloatBitness::X32 => lang_item_crate!("f32", "f32_runtime"),
                     FloatBitness::X64 => lang_item_crate!("f64", "f64_runtime"),
                 },
-                TypeCtor::Int(Uncertain::Known(i)) => lang_item_crate!(i.ty_to_string()),
+                TypeCtor::Int(i) => lang_item_crate!(i.ty_to_string()),
                 TypeCtor::Str => lang_item_crate!("str_alloc", "str"),
                 TypeCtor::Slice => lang_item_crate!("slice_alloc", "slice"),
                 TypeCtor::RawPtr(Mutability::Shared) => lang_item_crate!("const_ptr"),
diff --git a/crates/ra_hir_ty/src/primitive.rs b/crates/ra_hir_ty/src/primitive.rs
index 02a8179d9..37966b709 100644
--- a/crates/ra_hir_ty/src/primitive.rs
+++ b/crates/ra_hir_ty/src/primitive.rs
@@ -7,42 +7,6 @@ use std::fmt;
 
 pub use hir_def::builtin_type::{BuiltinFloat, BuiltinInt, FloatBitness, IntBitness, Signedness};
 
-#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
-pub enum Uncertain<T> {
-    Unknown,
-    Known(T),
-}
-
-impl From<IntTy> for Uncertain<IntTy> {
-    fn from(ty: IntTy) -> Self {
-        Uncertain::Known(ty)
-    }
-}
-
-impl fmt::Display for Uncertain<IntTy> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Uncertain::Unknown => write!(f, "{{integer}}"),
-            Uncertain::Known(ty) => write!(f, "{}", ty),
-        }
-    }
-}
-
-impl From<FloatTy> for Uncertain<FloatTy> {
-    fn from(ty: FloatTy) -> Self {
-        Uncertain::Known(ty)
-    }
-}
-
-impl fmt::Display for Uncertain<FloatTy> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            Uncertain::Unknown => write!(f, "{{float}}"),
-            Uncertain::Known(ty) => write!(f, "{}", ty),
-        }
-    }
-}
-
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
 pub struct IntTy {
     pub signedness: Signedness,
@@ -173,21 +137,3 @@ impl From<BuiltinFloat> for FloatTy {
         FloatTy { bitness: t.bitness }
     }
 }
-
-impl From<Option<BuiltinInt>> for Uncertain<IntTy> {
-    fn from(t: Option<BuiltinInt>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
-
-impl From<Option<BuiltinFloat>> for Uncertain<FloatTy> {
-    fn from(t: Option<BuiltinFloat>) -> Self {
-        match t {
-            None => Uncertain::Unknown,
-            Some(t) => Uncertain::Known(t.into()),
-        }
-    }
-}
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 8498d3d96..ad04e3e0f 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -7,9 +7,8 @@ use std::{
 
 use hir_def::{db::DefDatabase, AssocItemId, ModuleDefId, ModuleId};
 use hir_expand::{db::AstDatabase, diagnostics::DiagnosticSink};
-use ra_db::{
-    salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath, SourceDatabase, Upcast,
-};
+use ra_db::{salsa, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase, Upcast};
+use rustc_hash::FxHashSet;
 use stdx::format_to;
 
 use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
@@ -72,23 +71,12 @@ impl FileLoader for TestDB {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        extern_id: ra_db::ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl TestDB {
diff --git a/crates/ra_hir_ty/src/tests/display_source_code.rs b/crates/ra_hir_ty/src/tests/display_source_code.rs
index 4088b1d22..5dfa0a014 100644
--- a/crates/ra_hir_ty/src/tests/display_source_code.rs
+++ b/crates/ra_hir_ty/src/tests/display_source_code.rs
@@ -29,7 +29,7 @@ fn omit_default_type_parameters() {
         //- /main.rs
         struct Foo<T = u8> { t: T }
         fn main() {
-            let foo = Foo { t: 5 };
+            let foo = Foo { t: 5u8 };
             foo<|>;
         }
         ",
@@ -41,7 +41,7 @@ fn omit_default_type_parameters() {
         //- /main.rs
         struct Foo<K, T = u8> { k: K, t: T }
         fn main() {
-            let foo = Foo { k: 400, t: 5 };
+            let foo = Foo { k: 400, t: 5u8 };
             foo<|>;
         }
         ",
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
index 558a70022..804297315 100644
--- a/crates/ra_hir_ty/src/tests/method_resolution.rs
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -184,60 +184,6 @@ fn test() {
 }
 
 #[test]
-fn infer_associated_method_generics_with_default_param() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T=u32> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-}
-"#),
-        @r###"
-    80..104 '{     ...     }': Gen<T>
-    90..98 'loop { }': !
-    95..98 '{ }': ()
-    118..146 '{     ...e(); }': ()
-    128..129 'a': Gen<u32>
-    132..141 'Gen::make': fn make<u32>() -> Gen<u32>
-    132..143 'Gen::make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_tuple_param() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct Gen<T=()> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-    a.val<|>;
-}
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
 fn infer_associated_method_generics_without_args() {
     assert_snapshot!(
         infer(r#"
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index 88309157b..37659cd02 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -95,7 +95,7 @@ fn foo() {
 fn infer_ranges() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 fn test() {
     let a = ..;
     let b = 1..;
@@ -108,7 +108,7 @@ fn test() {
     t<|>;
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use prelude::*;
 mod prelude {}
 
@@ -1997,3 +1997,111 @@ fn foo() {
     "###
     );
 }
+
+#[test]
+fn generic_default() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test(t1: Thing, t2: OtherThing, t3: Thing<i32>, t4: OtherThing<i32>) {
+    t1.t;
+    t3.t;
+    match t2 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+    match t4 {
+        OtherThing::One { t } => { t; },
+        OtherThing::Two(t) => { t; },
+    }
+}
+"#),
+        @r###"
+    98..100 't1': Thing<()>
+    109..111 't2': OtherThing<()>
+    125..127 't3': Thing<i32>
+    141..143 't4': OtherThing<i32>
+    162..385 '{     ...   } }': ()
+    168..170 't1': Thing<()>
+    168..172 't1.t': ()
+    178..180 't3': Thing<i32>
+    178..182 't3.t': i32
+    188..283 'match ...     }': ()
+    194..196 't2': OtherThing<()>
+    207..228 'OtherT... { t }': OtherThing<()>
+    225..226 't': ()
+    232..238 '{ t; }': ()
+    234..235 't': ()
+    248..266 'OtherT...Two(t)': OtherThing<()>
+    264..265 't': ()
+    270..276 '{ t; }': ()
+    272..273 't': ()
+    288..383 'match ...     }': ()
+    294..296 't4': OtherThing<i32>
+    307..328 'OtherT... { t }': OtherThing<i32>
+    325..326 't': i32
+    332..338 '{ t; }': ()
+    334..335 't': i32
+    348..366 'OtherT...Two(t)': OtherThing<i32>
+    364..365 't': i32
+    370..376 '{ t; }': ()
+    372..373 't': i32
+    "###
+    );
+}
+
+#[test]
+fn generic_default_in_struct_literal() {
+    assert_snapshot!(
+        infer(r#"
+struct Thing<T = ()> { t: T }
+enum OtherThing<T = ()> {
+    One { t: T },
+    Two(T),
+}
+
+fn test() {
+    let x = Thing { t: loop {} };
+    let y = Thing { t: () };
+    let z = Thing { t: 1i32 };
+    if let Thing { t } = z {
+        t;
+    }
+
+    let a = OtherThing::One { t: 1i32 };
+    let b = OtherThing::Two(1i32);
+}
+"#),
+        @r###"
+    100..320 '{     ...32); }': ()
+    110..111 'x': Thing<!>
+    114..134 'Thing ...p {} }': Thing<!>
+    125..132 'loop {}': !
+    130..132 '{}': ()
+    144..145 'y': Thing<()>
+    148..163 'Thing { t: () }': Thing<()>
+    159..161 '()': ()
+    173..174 'z': Thing<i32>
+    177..194 'Thing ...1i32 }': Thing<i32>
+    188..192 '1i32': i32
+    200..241 'if let...     }': ()
+    207..218 'Thing { t }': Thing<i32>
+    215..216 't': i32
+    221..222 'z': Thing<i32>
+    223..241 '{     ...     }': ()
+    233..234 't': i32
+    251..252 'a': OtherThing<i32>
+    255..282 'OtherT...1i32 }': OtherThing<i32>
+    276..280 '1i32': i32
+    292..293 'b': OtherThing<i32>
+    296..311 'OtherThing::Two': Two<i32>(i32) -> OtherThing<i32>
+    296..317 'OtherT...(1i32)': OtherThing<i32>
+    312..316 '1i32': i32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index e8778d419..e81193a3c 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -10,7 +10,7 @@ use super::{infer, infer_with_mismatches, type_at, type_at_pos};
 fn infer_await() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 
 struct IntFuture;
 
@@ -24,7 +24,7 @@ fn test() {
     v<|>;
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     #[lang = "future_trait"]
@@ -42,7 +42,7 @@ mod future {
 fn infer_async() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 
 async fn foo() -> u64 {
     128
@@ -54,7 +54,7 @@ fn test() {
     v<|>;
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     #[lang = "future_trait"]
@@ -72,7 +72,7 @@ mod future {
 fn infer_desugar_async() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 
 async fn foo() -> u64 {
     128
@@ -83,7 +83,7 @@ fn test() {
     r<|>;
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 #[prelude_import] use future::*;
 mod future {
     trait Future {
@@ -100,7 +100,7 @@ mod future {
 fn infer_try() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 
 fn test() {
     let r: Result<i32, u64> = Result::Ok(1);
@@ -108,7 +108,7 @@ fn test() {
     v<|>;
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 
 #[prelude_import] use ops::*;
 mod ops {
@@ -140,9 +140,9 @@ mod result {
 fn infer_for_loop() {
     let (db, pos) = TestDB::with_position(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core,alloc
 
-use std::collections::Vec;
+use alloc::collections::Vec;
 
 fn test() {
     let v = Vec::new();
@@ -152,7 +152,7 @@ fn test() {
     }
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 
 #[prelude_import] use iter::*;
 mod iter {
@@ -161,6 +161,8 @@ mod iter {
     }
 }
 
+//- /alloc.rs crate:alloc deps:core
+
 mod collections {
     struct Vec<T> {}
     impl<T> Vec<T> {
@@ -168,7 +170,7 @@ mod collections {
         fn push(&mut self, t: T) { }
     }
 
-    impl<T> crate::iter::IntoIterator for Vec<T> {
+    impl<T> IntoIterator for Vec<T> {
         type Item=T;
     }
 }
@@ -1110,7 +1112,6 @@ fn test() {
 }
 
 #[test]
-#[ignore]
 fn impl_trait() {
     assert_snapshot!(
         infer(r#"
@@ -1161,6 +1162,95 @@ fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
 }
 
 #[test]
+fn simple_return_pos_impl_trait() {
+    mark::check!(lower_rpit);
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+}
+fn bar() -> impl Trait<u64> { loop {} }
+
+fn test() {
+    let a = bar();
+    a.foo();
+}
+"#),
+        @r###"
+    30..34 'self': &Self
+    72..83 '{ loop {} }': !
+    74..81 'loop {}': !
+    79..81 '{}': ()
+    95..130 '{     ...o(); }': ()
+    105..106 'a': impl Trait<u64>
+    109..112 'bar': fn bar() -> impl Trait<u64>
+    109..114 'bar()': impl Trait<u64>
+    120..121 'a': impl Trait<u64>
+    120..127 'a.foo()': u64
+    "###
+    );
+}
+
+#[test]
+fn more_return_pos_impl_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterator {
+    type Item;
+    fn next(&mut self) -> Self::Item;
+}
+trait Trait<T> {
+    fn foo(&self) -> T;
+}
+fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>) { loop {} }
+fn baz<T>(t: T) -> (impl Iterator<Item = impl Trait<T>>, impl Trait<T>) { loop {} }
+
+fn test() {
+    let (a, b) = bar();
+    a.next().foo();
+    b.foo();
+    let (c, d) = baz(1u128);
+    c.next().foo();
+    d.foo();
+}
+"#),
+        @r###"
+    50..54 'self': &mut Self
+    102..106 'self': &Self
+    185..196 '{ loop {} }': ({unknown}, {unknown})
+    187..194 'loop {}': !
+    192..194 '{}': ()
+    207..208 't': T
+    269..280 '{ loop {} }': ({unknown}, {unknown})
+    271..278 'loop {}': !
+    276..278 '{}': ()
+    292..414 '{     ...o(); }': ()
+    302..308 '(a, b)': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    303..304 'a': impl Iterator<Item = impl Trait<u32>>
+    306..307 'b': impl Trait<u64>
+    311..314 'bar': fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    311..316 'bar()': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
+    322..323 'a': impl Iterator<Item = impl Trait<u32>>
+    322..330 'a.next()': impl Trait<u32>
+    322..336 'a.next().foo()': u32
+    342..343 'b': impl Trait<u64>
+    342..349 'b.foo()': u64
+    359..365 '(c, d)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    360..361 'c': impl Iterator<Item = impl Trait<u128>>
+    363..364 'd': impl Trait<u128>
+    368..371 'baz': fn baz<u128>(u128) -> (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    368..378 'baz(1u128)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
+    372..377 '1u128': u128
+    384..385 'c': impl Iterator<Item = impl Trait<u128>>
+    384..392 'c.next()': impl Trait<u128>
+    384..398 'c.next().foo()': u128
+    404..405 'd': impl Trait<u128>
+    404..411 'd.foo()': u128
+    "###
+    );
+}
+
+#[test]
 fn dyn_trait() {
     assert_snapshot!(
         infer(r#"
@@ -1718,33 +1808,33 @@ fn test() {
 }
 "#),
         @r###"
-65..69 'self': &Self
-166..170 'self': Self
-172..176 'args': Args
-240..244 'self': &Foo
-255..257 '{}': ()
-335..336 'f': F
-355..357 '{}': ()
-444..690 '{     ...o(); }': ()
-454..459 'lazy1': Lazy<Foo, fn() -> T>
-476..485 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-476..493 'Lazy::...| Foo)': Lazy<Foo, fn() -> T>
-486..492 '|| Foo': || -> T
-489..492 'Foo': Foo
-503..505 'r1': {unknown}
-508..513 'lazy1': Lazy<Foo, fn() -> T>
-508..519 'lazy1.foo()': {unknown}
-561..576 'make_foo_fn_ptr': fn() -> Foo
-592..603 'make_foo_fn': fn make_foo_fn() -> Foo
-613..618 'lazy2': Lazy<Foo, fn() -> T>
-635..644 'Lazy::new': fn new<Foo, fn() -> T>(fn() -> T) -> Lazy<Foo, fn() -> T>
-635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> T>
-645..660 'make_foo_fn_ptr': fn() -> Foo
-671..673 'r2': {unknown}
-676..681 'lazy2': Lazy<Foo, fn() -> T>
-676..687 'lazy2.foo()': {unknown}
-550..552 '{}': ()
-"###
+    65..69 'self': &Self
+    166..170 'self': Self
+    172..176 'args': Args
+    240..244 'self': &Foo
+    255..257 '{}': ()
+    335..336 'f': F
+    355..357 '{}': ()
+    444..690 '{     ...o(); }': ()
+    454..459 'lazy1': Lazy<Foo, || -> Foo>
+    476..485 'Lazy::new': fn new<Foo, || -> Foo>(|| -> Foo) -> Lazy<Foo, || -> Foo>
+    476..493 'Lazy::...| Foo)': Lazy<Foo, || -> Foo>
+    486..492 '|| Foo': || -> Foo
+    489..492 'Foo': Foo
+    503..505 'r1': usize
+    508..513 'lazy1': Lazy<Foo, || -> Foo>
+    508..519 'lazy1.foo()': usize
+    561..576 'make_foo_fn_ptr': fn() -> Foo
+    592..603 'make_foo_fn': fn make_foo_fn() -> Foo
+    613..618 'lazy2': Lazy<Foo, fn() -> Foo>
+    635..644 'Lazy::new': fn new<Foo, fn() -> Foo>(fn() -> Foo) -> Lazy<Foo, fn() -> Foo>
+    635..661 'Lazy::...n_ptr)': Lazy<Foo, fn() -> Foo>
+    645..660 'make_foo_fn_ptr': fn() -> Foo
+    671..673 'r2': {unknown}
+    676..681 'lazy2': Lazy<Foo, fn() -> Foo>
+    676..687 'lazy2.foo()': {unknown}
+    550..552 '{}': ()
+    "###
     );
 }
 
@@ -2758,12 +2848,12 @@ fn test() {
 fn integer_range_iterate() {
     let t = type_at(
         r#"
-//- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:core
 fn test() {
     for x in 0..100 { x<|>; }
 }
 
-//- /std.rs crate:std
+//- /core.rs crate:core
 pub mod ops {
     pub struct Range<Idx> {
         pub start: Idx,
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 61de3cc30..a72a82f5a 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -4,7 +4,7 @@ use std::sync::Arc;
 use log::debug;
 
 use chalk_ir::{fold::shift::Shift, GenericArg, TypeName};
-use chalk_solve::rust_ir::{self, WellKnownTrait};
+use chalk_solve::rust_ir::{self, OpaqueTyDatumBound, WellKnownTrait};
 
 use hir_def::{
     lang_item::{lang_attr, LangItemTarget},
@@ -100,6 +100,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
     fn associated_ty_value(&self, id: AssociatedTyValueId) -> Arc<AssociatedTyValue> {
         self.db.associated_ty_value(self.krate, id)
     }
+
     fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<Interner>> {
         vec![]
     }
@@ -130,11 +131,34 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         self.db.program_clauses_for_chalk_env(self.krate, environment.clone())
     }
 
-    fn opaque_ty_data(
-        &self,
-        _id: chalk_ir::OpaqueTyId<Interner>,
-    ) -> Arc<rust_ir::OpaqueTyDatum<Interner>> {
-        unimplemented!()
+    fn opaque_ty_data(&self, id: chalk_ir::OpaqueTyId<Interner>) -> Arc<OpaqueTyDatum> {
+        let interned_id = crate::db::InternedOpaqueTyId::from(id);
+        let full_id = self.db.lookup_intern_impl_trait_id(interned_id);
+        let (func, idx) = match full_id {
+            crate::OpaqueTyId::ReturnTypeImplTrait(func, idx) => (func, idx),
+        };
+        let datas =
+            self.db.return_type_impl_traits(func).expect("impl trait id without impl traits");
+        let data = &datas.value.impl_traits[idx as usize];
+        let bound = OpaqueTyDatumBound {
+            bounds: make_binders(
+                data.bounds
+                    .value
+                    .iter()
+                    .cloned()
+                    .filter(|b| !b.is_error())
+                    .map(|b| b.to_chalk(self.db))
+                    .collect(),
+                1,
+            ),
+        };
+        let num_vars = datas.num_binders;
+        Arc::new(OpaqueTyDatum { opaque_ty_id: id, bound: make_binders(bound, num_vars) })
+    }
+
+    fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
+        // FIXME: actually provide the hidden type; it is relevant for auto traits
+        Ty::Unknown.to_chalk(self.db)
     }
 
     fn force_impl_for(
@@ -150,10 +174,6 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         // FIXME: implement actual object safety
         true
     }
-
-    fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
-        Ty::Unknown.to_chalk(self.db)
-    }
 }
 
 pub(crate) fn program_clauses_for_chalk_env_query(
@@ -460,6 +480,18 @@ impl From<crate::traits::GlobalImplId> for ImplId {
     }
 }
 
+impl From<OpaqueTyId> for crate::db::InternedOpaqueTyId {
+    fn from(id: OpaqueTyId) -> Self {
+        InternKey::from_intern_id(id.0)
+    }
+}
+
+impl From<crate::db::InternedOpaqueTyId> for OpaqueTyId {
+    fn from(id: crate::db::InternedOpaqueTyId) -> Self {
+        chalk_ir::OpaqueTyId(id.as_intern_id())
+    }
+}
+
 impl From<rust_ir::AssociatedTyValueId<Interner>> for crate::traits::AssocTyValueId {
     fn from(id: rust_ir::AssociatedTyValueId<Interner>) -> Self {
         Self::from_intern_id(id.0)
diff --git a/crates/ra_hir_ty/src/traits/chalk/interner.rs b/crates/ra_hir_ty/src/traits/chalk/interner.rs
index e27074ba6..56aab640c 100644
--- a/crates/ra_hir_ty/src/traits/chalk/interner.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/interner.rs
@@ -22,6 +22,8 @@ pub type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interne
 pub type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
 pub type FnDefId = chalk_ir::FnDefId<Interner>;
 pub type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
+pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
+pub type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
 
 impl chalk_ir::interner::Interner for Interner {
     type InternedType = Box<chalk_ir::TyData<Self>>; // FIXME use Arc?
diff --git a/crates/ra_hir_ty/src/traits/chalk/mapping.rs b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
index 5f6daf842..18e5c9c16 100644
--- a/crates/ra_hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/mapping.rs
@@ -14,10 +14,10 @@ use ra_db::salsa::InternKey;
 
 use crate::{
     db::HirDatabase,
-    primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness, Uncertain},
+    primitive::{FloatBitness, FloatTy, IntBitness, IntTy, Signedness},
     traits::{builtin, AssocTyValue, Canonical, Impl, Obligation},
-    ApplicationTy, CallableDef, GenericPredicate, InEnvironment, ProjectionPredicate, ProjectionTy,
-    Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
+    ApplicationTy, CallableDef, GenericPredicate, InEnvironment, OpaqueTy, OpaqueTyId,
+    ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeCtor,
 };
 
 use super::interner::*;
@@ -68,7 +68,16 @@ impl ToChalk for Ty {
                 let bounded_ty = chalk_ir::DynTy { bounds: make_binders(where_clauses, 1) };
                 chalk_ir::TyData::Dyn(bounded_ty).intern(&Interner)
             }
-            Ty::Opaque(_) | Ty::Unknown => {
+            Ty::Opaque(opaque_ty) => {
+                let opaque_ty_id = opaque_ty.opaque_ty_id.to_chalk(db);
+                let substitution = opaque_ty.parameters.to_chalk(db);
+                chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
+                    opaque_ty_id,
+                    substitution,
+                }))
+                .intern(&Interner)
+            }
+            Ty::Unknown => {
                 let substitution = chalk_ir::Substitution::empty(&Interner);
                 let name = TypeName::Error;
                 chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
@@ -98,7 +107,11 @@ impl ToChalk for Ty {
                 let parameters = from_chalk(db, proj.substitution);
                 Ty::Projection(ProjectionTy { associated_ty, parameters })
             }
-            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(_)) => unimplemented!(),
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
+                let impl_trait_id = from_chalk(db, opaque_ty.opaque_ty_id);
+                let parameters = from_chalk(db, opaque_ty.substitution);
+                Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
+            }
             chalk_ir::TyData::Function(chalk_ir::Fn { num_binders: _, substitution }) => {
                 let parameters: Substs = from_chalk(db, substitution);
                 Ty::Apply(ApplicationTy {
@@ -204,6 +217,21 @@ impl ToChalk for hir_def::TraitId {
     }
 }
 
+impl ToChalk for OpaqueTyId {
+    type Chalk = chalk_ir::OpaqueTyId<Interner>;
+
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::OpaqueTyId<Interner> {
+        db.intern_impl_trait_id(self).into()
+    }
+
+    fn from_chalk(
+        db: &dyn HirDatabase,
+        opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
+    ) -> OpaqueTyId {
+        db.lookup_intern_impl_trait_id(opaque_ty_id.into())
+    }
+}
+
 impl ToChalk for TypeCtor {
     type Chalk = TypeName<Interner>;
 
@@ -214,13 +242,18 @@ impl ToChalk for TypeCtor {
                 TypeName::AssociatedType(type_id)
             }
 
+            TypeCtor::OpaqueType(impl_trait_id) => {
+                let id = impl_trait_id.to_chalk(db);
+                TypeName::OpaqueType(id)
+            }
+
             TypeCtor::Bool => TypeName::Scalar(Scalar::Bool),
             TypeCtor::Char => TypeName::Scalar(Scalar::Char),
-            TypeCtor::Int(Uncertain::Known(int_ty)) => TypeName::Scalar(int_ty_to_chalk(int_ty)),
-            TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X32 })) => {
+            TypeCtor::Int(int_ty) => TypeName::Scalar(int_ty_to_chalk(int_ty)),
+            TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 }) => {
                 TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32))
             }
-            TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X64 })) => {
+            TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 }) => {
                 TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64))
             }
 
@@ -235,9 +268,7 @@ impl ToChalk for TypeCtor {
             }
             TypeCtor::Never => TypeName::Never,
 
-            TypeCtor::Int(Uncertain::Unknown)
-            | TypeCtor::Float(Uncertain::Unknown)
-            | TypeCtor::Adt(_)
+            TypeCtor::Adt(_)
             | TypeCtor::Array
             | TypeCtor::FnPtr { .. }
             | TypeCtor::Closure { .. } => {
@@ -252,23 +283,25 @@ impl ToChalk for TypeCtor {
         match type_name {
             TypeName::Adt(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
             TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
-            TypeName::OpaqueType(_) => unreachable!(),
+            TypeName::OpaqueType(opaque_type_id) => {
+                TypeCtor::OpaqueType(from_chalk(db, opaque_type_id))
+            }
 
             TypeName::Scalar(Scalar::Bool) => TypeCtor::Bool,
             TypeName::Scalar(Scalar::Char) => TypeCtor::Char,
-            TypeName::Scalar(Scalar::Int(int_ty)) => TypeCtor::Int(Uncertain::Known(IntTy {
+            TypeName::Scalar(Scalar::Int(int_ty)) => TypeCtor::Int(IntTy {
                 signedness: Signedness::Signed,
                 bitness: bitness_from_chalk_int(int_ty),
-            })),
-            TypeName::Scalar(Scalar::Uint(uint_ty)) => TypeCtor::Int(Uncertain::Known(IntTy {
+            }),
+            TypeName::Scalar(Scalar::Uint(uint_ty)) => TypeCtor::Int(IntTy {
                 signedness: Signedness::Unsigned,
                 bitness: bitness_from_chalk_uint(uint_ty),
-            })),
+            }),
             TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32)) => {
-                TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X32 }))
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 })
             }
             TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64)) => {
-                TypeCtor::Float(Uncertain::Known(FloatTy { bitness: FloatBitness::X64 }))
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 })
             }
             TypeName::Tuple(cardinality) => TypeCtor::Tuple { cardinality: cardinality as u16 },
             TypeName::Raw(mutability) => TypeCtor::RawPtr(from_chalk(db, mutability)),
@@ -447,6 +480,11 @@ impl ToChalk for GenericPredicate {
                 let ty = from_chalk(db, projection_eq.ty);
                 GenericPredicate::Projection(ProjectionPredicate { projection_ty, ty })
             }
+
+            chalk_ir::WhereClause::LifetimeOutlives(_) => {
+                // we shouldn't get these from Chalk
+                panic!("encountered LifetimeOutlives from Chalk")
+            }
         }
     }
 }
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index d88828c7c..556af7098 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -69,6 +69,11 @@ impl DebugContext<'_> {
                 let name = self.0.type_alias_data(type_alias).name.clone();
                 write!(f, "{}::{}", trait_name, name)?;
             }
+            TypeCtor::OpaqueType(opaque_ty_id) => match opaque_ty_id {
+                crate::OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                    write!(f, "{{impl trait {} of {:?}}}", idx, func)?;
+                }
+            },
             TypeCtor::Closure { def, expr } => {
                 write!(f, "{{closure {:?} in ", expr.into_raw())?;
                 match def {
diff --git a/crates/ra_ide/src/completion.rs b/crates/ra_ide/src/completion.rs
index fa37b6955..e1fcf379d 100644
--- a/crates/ra_ide/src/completion.rs
+++ b/crates/ra_ide/src/completion.rs
@@ -126,3 +126,81 @@ pub(crate) fn completions(
 
     Some(acc)
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::completion_config::CompletionConfig;
+    use crate::mock_analysis::analysis_and_position;
+
+    struct DetailAndDocumentation<'a> {
+        detail: &'a str,
+        documentation: &'a str,
+    }
+
+    fn check_detail_and_documentation(fixture: &str, expected: DetailAndDocumentation) {
+        let (analysis, position) = analysis_and_position(fixture);
+        let config = CompletionConfig::default();
+        let completions = analysis.completions(&config, position).unwrap().unwrap();
+        for item in completions {
+            if item.detail() == Some(expected.detail) {
+                let opt = item.documentation();
+                let doc = opt.as_ref().map(|it| it.as_str());
+                assert_eq!(doc, Some(expected.documentation));
+                return;
+            }
+        }
+        panic!("completion detail not found: {}", expected.detail)
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_attr() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        #[doc = "Do the foo"]
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: "Do the foo" },
+        );
+    }
+
+    #[test]
+    fn test_completion_detail_from_macro_generated_struct_fn_doc_comment() {
+        check_detail_and_documentation(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        /// Do the foo
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>;
+            }
+            "#,
+            DetailAndDocumentation { detail: "fn foo(&self)", documentation: " Do the foo" },
+        );
+    }
+}
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 15dc50cf1..e1bfd72f9 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -21,7 +21,7 @@ use ra_syntax::{
 };
 use ra_text_edit::{TextEdit, TextEditBuilder};
 
-use crate::{Diagnostic, FileId, FileSystemEdit, Fix, SourceChange, SourceFileEdit};
+use crate::{Diagnostic, FileId, FileSystemEdit, Fix, SourceFileEdit};
 
 #[derive(Debug, Copy, Clone)]
 pub enum Severity {
@@ -115,7 +115,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         let node = d.ast(db);
         let replacement = format!("Ok({})", node.syntax());
         let edit = TextEdit::replace(node.syntax().text_range(), replacement);
-        let source_change = SourceChange::source_file_edit_from(file_id, edit);
+        let source_change = SourceFileEdit { file_id, edit }.into();
         let fix = Fix::new("Wrap with ok", source_change);
         res.borrow_mut().push(Diagnostic {
             range: sema.diagnostics_range(d).range,
@@ -187,7 +187,8 @@ fn check_struct_shorthand_initialization(
         if let (Some(name_ref), Some(expr)) = (record_field.name_ref(), record_field.expr()) {
             let field_name = name_ref.syntax().text().to_string();
             let field_expr = expr.syntax().text().to_string();
-            if field_name == field_expr {
+            let field_name_is_tup_index = name_ref.as_tuple_field().is_some();
+            if field_name == field_expr && !field_name_is_tup_index {
                 let mut edit_builder = TextEditBuilder::default();
                 edit_builder.delete(record_field.syntax().text_range());
                 edit_builder.insert(record_field.syntax().text_range().start(), field_name);
@@ -321,29 +322,26 @@ mod tests {
     fn test_wrap_return_type() {
         let before = r#"
             //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
-            fn div(x: i32, y: i32) -> Result<i32, String> {
+            fn div(x: i32, y: i32) -> Result<i32, ()> {
                 if y == 0 {
-                    return Err("div by zero".into());
+                    return Err(());
                 }
                 x / y<|>
             }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
+            //- /core/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
         "#;
         let after = r#"
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
-            fn div(x: i32, y: i32) -> Result<i32, String> {
+            fn div(x: i32, y: i32) -> Result<i32, ()> {
                 if y == 0 {
-                    return Err("div by zero".into());
+                    return Err(());
                 }
                 Ok(x / y)
             }
@@ -355,7 +353,7 @@ mod tests {
     fn test_wrap_return_type_handles_generic_functions() {
         let before = r#"
             //- /main.rs
-            use std::result::Result::{self, Ok, Err};
+            use core::result::Result::{self, Ok, Err};
 
             fn div<T>(x: T) -> Result<T, i32> {
                 if x == 0 {
@@ -364,13 +362,13 @@ mod tests {
                 <|>x
             }
 
-            //- /std/lib.rs
+            //- /core/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
         "#;
         let after = r#"
-            use std::result::Result::{self, Ok, Err};
+            use core::result::Result::{self, Ok, Err};
 
             fn div<T>(x: T) -> Result<T, i32> {
                 if x == 0 {
@@ -386,32 +384,29 @@ mod tests {
     fn test_wrap_return_type_handles_type_aliases() {
         let before = r#"
             //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
-            type MyResult<T> = Result<T, String>;
+            type MyResult<T> = Result<T, ()>;
 
             fn div(x: i32, y: i32) -> MyResult<i32> {
                 if y == 0 {
-                    return Err("div by zero".into());
+                    return Err(());
                 }
                 x <|>/ y
             }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
+            //- /core/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
         "#;
         let after = r#"
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
-            type MyResult<T> = Result<T, String>;
+            type MyResult<T> = Result<T, ()>;
             fn div(x: i32, y: i32) -> MyResult<i32> {
                 if y == 0 {
-                    return Err("div by zero".into());
+                    return Err(());
                 }
                 Ok(x / y)
             }
@@ -423,16 +418,13 @@ mod tests {
     fn test_wrap_return_type_not_applicable_when_expr_type_does_not_match_ok_type() {
         let content = r#"
             //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
-            fn foo() -> Result<String, i32> {
+            fn foo() -> Result<(), i32> {
                 0<|>
             }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
+            //- /core/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
@@ -444,7 +436,7 @@ mod tests {
     fn test_wrap_return_type_not_applicable_when_return_type_is_not_result() {
         let content = r#"
             //- /main.rs
-            use std::{string::String, result::Result::{self, Ok, Err}};
+            use core::result::Result::{self, Ok, Err};
 
             enum SomeOtherEnum {
                 Ok(i32),
@@ -455,10 +447,7 @@ mod tests {
                 0<|>
             }
 
-            //- /std/lib.rs
-            pub mod string {
-                pub struct String { }
-            }
+            //- /core/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
@@ -731,6 +720,18 @@ mod tests {
         "#,
             check_struct_shorthand_initialization,
         );
+        check_not_applicable(
+            r#"
+            struct A(usize);
+
+            fn main() {
+                A {
+                    0: 0
+                }
+            }
+        "#,
+            check_struct_shorthand_initialization,
+        );
 
         check_apply(
             r#"
diff --git a/crates/ra_ide/src/display/function_signature.rs b/crates/ra_ide/src/display/function_signature.rs
index 9572debd8..ca8a6a650 100644
--- a/crates/ra_ide/src/display/function_signature.rs
+++ b/crates/ra_ide/src/display/function_signature.rs
@@ -10,7 +10,7 @@ use std::{
 use hir::{Docs, Documentation, HasSource, HirDisplay};
 use ra_ide_db::RootDatabase;
 use ra_syntax::ast::{self, AstNode, NameOwner, VisibilityOwner};
-use stdx::SepBy;
+use stdx::{split1, SepBy};
 
 use crate::display::{generic_parameters, where_predicates};
 
@@ -207,7 +207,16 @@ impl From<&'_ ast::FnDef> for FunctionSignature {
                     res.push(raw_param);
                 }
 
-                res.extend(param_list.params().map(|param| param.syntax().text().to_string()));
+                // macro-generated functions are missing whitespace
+                fn fmt_param(param: ast::Param) -> String {
+                    let text = param.syntax().text().to_string();
+                    match split1(&text, ':') {
+                        Some((left, right)) => format!("{}: {}", left.trim(), right.trim()),
+                        _ => text,
+                    }
+                }
+
+                res.extend(param_list.params().map(fmt_param));
                 res_types.extend(param_list.params().map(|param| {
                     let param_text = param.syntax().text().to_string();
                     match param_text.split(':').nth(1).and_then(|it| it.get(1..)) {
diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index 5da28edd2..c7bb1e69f 100644
--- a/crates/ra_ide/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -92,15 +92,16 @@ impl NavigationTarget {
         let name = module.name(db).map(|it| it.to_string().into()).unwrap_or_default();
         if let Some(src) = module.declaration_source(db) {
             let frange = original_range(db, src.as_ref().map(|it| it.syntax()));
-            return NavigationTarget::from_syntax(
+            let mut res = NavigationTarget::from_syntax(
                 frange.file_id,
                 name,
                 None,
                 frange.range,
                 src.value.syntax().kind(),
-                src.value.doc_comment_text(),
-                src.value.short_label(),
             );
+            res.docs = src.value.doc_comment_text();
+            res.description = src.value.short_label();
+            return res;
         }
         module.to_nav(db)
     }
@@ -130,11 +131,9 @@ impl NavigationTarget {
     }
 
     /// Allows `NavigationTarget` to be created from a `NameOwner`
-    fn from_named(
+    pub(crate) fn from_named(
         db: &RootDatabase,
         node: InFile<&dyn ast::NameOwner>,
-        docs: Option<String>,
-        description: Option<String>,
     ) -> NavigationTarget {
         //FIXME: use `_` instead of empty string
         let name = node.value.name().map(|it| it.text().clone()).unwrap_or_default();
@@ -148,8 +147,6 @@ impl NavigationTarget {
             focus_range,
             frange.range,
             node.value.syntax().kind(),
-            docs,
-            description,
         )
     }
 
@@ -159,8 +156,6 @@ impl NavigationTarget {
         focus_range: Option<TextRange>,
         full_range: TextRange,
         kind: SyntaxKind,
-        docs: Option<String>,
-        description: Option<String>,
     ) -> NavigationTarget {
         NavigationTarget {
             file_id,
@@ -169,8 +164,8 @@ impl NavigationTarget {
             full_range,
             focus_range,
             container_name: None,
-            description,
-            docs,
+            description: None,
+            docs: None,
         }
     }
 }
@@ -238,12 +233,11 @@ where
 {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
-        NavigationTarget::from_named(
-            db,
-            src.as_ref().map(|it| it as &dyn ast::NameOwner),
-            src.value.doc_comment_text(),
-            src.value.short_label(),
-        )
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res.description = src.value.short_label();
+        res
     }
 }
 
@@ -258,15 +252,7 @@ impl ToNav for hir::Module {
             }
         };
         let frange = original_range(db, src.with_value(syntax));
-        NavigationTarget::from_syntax(
-            frange.file_id,
-            name,
-            focus,
-            frange.range,
-            syntax.kind(),
-            None,
-            None,
-        )
+        NavigationTarget::from_syntax(frange.file_id, name, focus, frange.range, syntax.kind())
     }
 }
 
@@ -285,8 +271,6 @@ impl ToNav for hir::ImplDef {
             None,
             frange.range,
             src.value.syntax().kind(),
-            None,
-            None,
         )
     }
 }
@@ -296,12 +280,12 @@ impl ToNav for hir::Field {
         let src = self.source(db);
 
         match &src.value {
-            FieldSource::Named(it) => NavigationTarget::from_named(
-                db,
-                src.with_value(it),
-                it.doc_comment_text(),
-                it.short_label(),
-            ),
+            FieldSource::Named(it) => {
+                let mut res = NavigationTarget::from_named(db, src.with_value(it));
+                res.docs = it.doc_comment_text();
+                res.description = it.short_label();
+                res
+            }
             FieldSource::Pos(it) => {
                 let frange = original_range(db, src.with_value(it.syntax()));
                 NavigationTarget::from_syntax(
@@ -310,8 +294,6 @@ impl ToNav for hir::Field {
                     None,
                     frange.range,
                     it.syntax().kind(),
-                    None,
-                    None,
                 )
             }
         }
@@ -322,12 +304,10 @@ impl ToNav for hir::MacroDef {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         let src = self.source(db);
         log::debug!("nav target {:#?}", src.value.syntax());
-        NavigationTarget::from_named(
-            db,
-            src.as_ref().map(|it| it as &dyn ast::NameOwner),
-            src.value.doc_comment_text(),
-            None,
-        )
+        let mut res =
+            NavigationTarget::from_named(db, src.as_ref().map(|it| it as &dyn ast::NameOwner));
+        res.docs = src.value.doc_comment_text();
+        res
     }
 }
 
diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index a6c86e99c..0798d2c36 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -1,6 +1,6 @@
 use hir::Semantics;
 use ra_ide_db::{
-    defs::{classify_name, classify_name_ref},
+    defs::{classify_name, classify_name_ref, NameClass},
     symbol_index, RootDatabase,
 };
 use ra_syntax::{
@@ -39,7 +39,10 @@ pub(crate) fn goto_definition(
                 reference_definition(&sema, &name_ref).to_vec()
             },
             ast::Name(name) => {
-                let def = classify_name(&sema, &name)?.definition();
+                let def = match classify_name(&sema, &name)? {
+                    NameClass::Definition(def) | NameClass::ConstReference(def) => def,
+                    NameClass::FieldShorthand { local: _, field } => field,
+                };
                 let nav = def.try_to_nav(sema.db)?;
                 vec![nav]
             },
@@ -886,4 +889,23 @@ mod tests {
             "x",
         )
     }
+
+    #[test]
+    fn goto_def_for_enum_variant_field() {
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo {
+                Bar { x: i32 }
+            }
+            fn baz(foo: Foo) {
+                match foo {
+                    Foo::Bar { x<|> } => x
+                };
+            }
+            ",
+            "x RECORD_FIELD_DEF FileId(1) 21..27 21..22",
+            "x: i32|x",
+        );
+    }
 }
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index d96cb5596..ad78b7671 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -1,8 +1,8 @@
 use std::iter::once;
 
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, FieldSource, HasSource, HirDisplay, ModuleDef,
-    ModuleSource, Semantics,
+    Adt, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource, HirDisplay,
+    ModuleDef, ModuleSource, Semantics,
 };
 use itertools::Itertools;
 use ra_db::SourceDatabase;
@@ -10,22 +10,55 @@ use ra_ide_db::{
     defs::{classify_name, classify_name_ref, Definition},
     RootDatabase,
 };
-use ra_syntax::{
-    ast::{self, DocCommentsOwner},
-    match_ast, AstNode,
-    SyntaxKind::*,
-    SyntaxToken, TokenAtOffset,
-};
+use ra_syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset};
 
 use crate::{
-    display::{macro_label, rust_code_markup, rust_code_markup_with_doc, ShortLabel},
-    FilePosition, RangeInfo,
+    display::{macro_label, rust_code_markup, rust_code_markup_with_doc, ShortLabel, ToNav},
+    runnables::runnable,
+    FileId, FilePosition, NavigationTarget, RangeInfo, Runnable,
 };
+use test_utils::mark;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct HoverConfig {
+    pub implementations: bool,
+    pub run: bool,
+    pub debug: bool,
+}
+
+impl Default for HoverConfig {
+    fn default() -> Self {
+        Self { implementations: true, run: true, debug: true }
+    }
+}
+
+impl HoverConfig {
+    pub const NO_ACTIONS: Self = Self { implementations: false, run: false, debug: false };
+
+    pub fn any(&self) -> bool {
+        self.implementations || self.runnable()
+    }
+
+    pub fn none(&self) -> bool {
+        !self.any()
+    }
+
+    pub fn runnable(&self) -> bool {
+        self.run || self.debug
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum HoverAction {
+    Runnable(Runnable),
+    Implementaion(FilePosition),
+}
 
 /// Contains the results when hovering over an item
 #[derive(Debug, Default)]
 pub struct HoverResult {
     results: Vec<String>,
+    actions: Vec<HoverAction>,
 }
 
 impl HoverResult {
@@ -53,10 +86,20 @@ impl HoverResult {
         &self.results
     }
 
+    pub fn actions(&self) -> &[HoverAction] {
+        &self.actions
+    }
+
+    pub fn push_action(&mut self, action: HoverAction) {
+        self.actions.push(action);
+    }
+
     /// Returns the results converted into markup
     /// for displaying in a UI
+    ///
+    /// Does not process actions!
     pub fn to_markup(&self) -> String {
-        self.results.join("\n\n---\n")
+        self.results.join("\n\n___\n")
     }
 }
 
@@ -87,6 +130,14 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
         res.extend(hover_text_from_name_kind(db, name_kind));
 
         if !res.is_empty() {
+            if let Some(action) = show_implementations_action(db, name_kind) {
+                res.push_action(action);
+            }
+
+            if let Some(action) = runnable_action(&sema, name_kind, position.file_id) {
+                res.push_action(action);
+            }
+
             return Some(RangeInfo::new(range, res));
         }
     }
@@ -117,6 +168,56 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
     Some(RangeInfo::new(range, res))
 }
 
+fn show_implementations_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    fn to_action(nav_target: NavigationTarget) -> HoverAction {
+        HoverAction::Implementaion(FilePosition {
+            file_id: nav_target.file_id(),
+            offset: nav_target.range().start(),
+        })
+    }
+
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Adt(Adt::Struct(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Union(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Adt(Adt::Enum(it)) => Some(to_action(it.to_nav(db))),
+            ModuleDef::Trait(it) => Some(to_action(it.to_nav(db))),
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
+fn runnable_action(
+    sema: &Semantics<RootDatabase>,
+    def: Definition,
+    file_id: FileId,
+) -> Option<HoverAction> {
+    match def {
+        Definition::ModuleDef(it) => match it {
+            ModuleDef::Module(it) => match it.definition_source(sema.db).value {
+                ModuleSource::Module(it) => runnable(&sema, it.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it)),
+                _ => None,
+            },
+            ModuleDef::Function(it) => {
+                let src = it.source(sema.db);
+                if src.file_id != file_id.into() {
+                    mark::hit!(hover_macro_generated_struct_fn_doc_comment);
+                    mark::hit!(hover_macro_generated_struct_fn_doc_attr);
+
+                    return None;
+                }
+
+                runnable(&sema, src.value.syntax().clone(), file_id)
+                    .map(|it| HoverAction::Runnable(it))
+            }
+            _ => None,
+        },
+        _ => None,
+    }
+}
+
 fn hover_text(
     docs: Option<String>,
     desc: Option<String>,
@@ -169,13 +270,15 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
     return match def {
         Definition::Macro(it) => {
             let src = it.source(db);
-            hover_text(src.value.doc_comment_text(), Some(macro_label(&src.value)), mod_path)
+            let docs = Documentation::from_ast(&src.value).map(Into::into);
+            hover_text(docs, Some(macro_label(&src.value)), mod_path)
         }
         Definition::Field(it) => {
             let src = it.source(db);
             match src.value {
                 FieldSource::Named(it) => {
-                    hover_text(it.doc_comment_text(), it.short_label(), mod_path)
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_text(docs, it.short_label(), mod_path)
                 }
                 _ => None,
             }
@@ -183,7 +286,8 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
         Definition::ModuleDef(it) => match it {
             ModuleDef::Module(it) => match it.definition_source(db).value {
                 ModuleSource::Module(it) => {
-                    hover_text(it.doc_comment_text(), it.short_label(), mod_path)
+                    let docs = Documentation::from_ast(&it).map(Into::into);
+                    hover_text(docs, it.short_label(), mod_path)
                 }
                 _ => None,
             },
@@ -208,10 +312,11 @@ fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<Strin
     fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<String>
     where
         D: HasSource<Ast = A>,
-        A: ast::DocCommentsOwner + ast::NameOwner + ShortLabel,
+        A: ast::DocCommentsOwner + ast::NameOwner + ShortLabel + ast::AttrsOwner,
     {
         let src = def.source(db);
-        hover_text(src.value.doc_comment_text(), src.value.short_label(), mod_path)
+        let docs = Documentation::from_ast(&src.value).map(Into::into);
+        hover_text(docs, src.value.short_label(), mod_path)
     }
 }
 
@@ -229,6 +334,9 @@ fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+    use insta::assert_debug_snapshot;
+
     use ra_db::FileLoader;
     use ra_syntax::TextRange;
 
@@ -242,7 +350,15 @@ mod tests {
         s.map(trim_markup)
     }
 
-    fn check_hover_result(fixture: &str, expected: &[&str]) -> String {
+    fn assert_impl_action(action: &HoverAction, position: u32) {
+        let offset = match action {
+            HoverAction::Implementaion(pos) => pos.offset,
+            it => panic!("Unexpected hover action: {:#?}", it),
+        };
+        assert_eq!(offset, position.into());
+    }
+
+    fn check_hover_result(fixture: &str, expected: &[&str]) -> (String, Vec<HoverAction>) {
         let (analysis, position) = analysis_and_position(fixture);
         let hover = analysis.hover(position).unwrap().unwrap();
         let mut results = Vec::from(hover.info.results());
@@ -257,7 +373,7 @@ mod tests {
         assert_eq!(hover.info.len(), expected.len());
 
         let content = analysis.db.file_text(position.file_id);
-        content[hover.range].to_string()
+        (content[hover.range].to_string(), hover.info.actions().to_vec())
     }
 
     fn check_hover_no_result(fixture: &str) {
@@ -458,7 +574,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let zz<|> = Test { t: 23, k: 33 };
+    let zz<|> = Test { t: 23u8, k: 33 };
 }"#,
             &["Test<i32, u8>"],
         );
@@ -747,7 +863,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_macro() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             "
             //- /lib.rs
             macro_rules! id {
@@ -768,7 +884,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_expr_in_macro() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             "
             //- /lib.rs
             macro_rules! id {
@@ -786,7 +902,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_expr_in_macro_recursive() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             "
             //- /lib.rs
             macro_rules! id_deep {
@@ -807,7 +923,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_func_in_macro_recursive() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             "
             //- /lib.rs
             macro_rules! id_deep {
@@ -831,7 +947,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_literal_string_in_macro() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             r#"
             //- /lib.rs
             macro_rules! arr {
@@ -850,7 +966,7 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_through_assert_macro() {
-        let hover_on = check_hover_result(
+        let (hover_on, _) = check_hover_result(
             r#"
             //- /lib.rs
             #[rustc_builtin_macro]
@@ -926,13 +1042,14 @@ fn func(foo: i32) { if true { <|>foo; }; }
 
     #[test]
     fn test_hover_trait_show_qualifiers() {
-        check_hover_result(
+        let (_, actions) = check_hover_result(
             "
             //- /lib.rs
             unsafe trait foo<|>() {}
             ",
             &["unsafe trait foo"],
         );
+        assert_impl_action(&actions[0], 13);
     }
 
     #[test]
@@ -951,4 +1068,246 @@ fn func(foo: i32) { if true { <|>foo; }; }
             &["mod my"],
         );
     }
+
+    #[test]
+    fn test_hover_struct_doc_comment() {
+        check_hover_result(
+            r#"
+            //- /lib.rs
+            /// bar docs
+            struct Bar;
+
+            fn foo() {
+                let bar = Ba<|>r;
+            }
+            "#,
+            &["struct Bar\n```\n___\n\nbar docs"],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr() {
+        check_hover_result(
+            r#"
+            //- /lib.rs
+            #[doc = "bar docs"]
+            struct Bar;
+
+            fn foo() {
+                let bar = Ba<|>r;
+            }
+            "#,
+            &["struct Bar\n```\n___\n\nbar docs"],
+        );
+    }
+
+    #[test]
+    fn test_hover_struct_doc_attr_multiple_and_mixed() {
+        check_hover_result(
+            r#"
+            //- /lib.rs
+            /// bar docs 0
+            #[doc = "bar docs 1"]
+            #[doc = "bar docs 2"]
+            struct Bar;
+
+            fn foo() {
+                let bar = Ba<|>r;
+            }
+            "#,
+            &["struct Bar\n```\n___\n\nbar docs 0\n\nbar docs 1\n\nbar docs 2"],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_comment() {
+        mark::check!(hover_macro_generated_struct_fn_doc_comment);
+
+        check_hover_result(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        /// Do the foo
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>o();
+            }
+            "#,
+            &["Bar\n```\n\n```rust\nfn foo(&self)\n```\n___\n\n Do the foo"],
+        );
+    }
+
+    #[test]
+    fn test_hover_macro_generated_struct_fn_doc_attr() {
+        mark::check!(hover_macro_generated_struct_fn_doc_attr);
+
+        check_hover_result(
+            r#"
+            //- /lib.rs
+            macro_rules! bar {
+                () => {
+                    struct Bar;
+                    impl Bar {
+                        #[doc = "Do the foo"]
+                        fn foo(&self) {}
+                    }
+                }
+            }
+
+            bar!();
+
+            fn foo() {
+                let bar = Bar;
+                bar.fo<|>o();
+            }
+            "#,
+            &["Bar\n```\n\n```rust\nfn foo(&self)\n```\n___\n\nDo the foo"],
+        );
+    }
+
+    #[test]
+    fn test_hover_trait_has_impl_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait foo<|>() {}
+            ",
+            &["trait foo"],
+        );
+        assert_impl_action(&actions[0], 6);
+    }
+
+    #[test]
+    fn test_hover_struct_has_impl_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            struct foo<|>() {}
+            ",
+            &["struct foo"],
+        );
+        assert_impl_action(&actions[0], 7);
+    }
+
+    #[test]
+    fn test_hover_union_has_impl_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            union foo<|>() {}
+            ",
+            &["union foo"],
+        );
+        assert_impl_action(&actions[0], 6);
+    }
+
+    #[test]
+    fn test_hover_enum_has_impl_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            enum foo<|>() {
+                A,
+                B
+            }
+            ",
+            &["enum foo"],
+        );
+        assert_impl_action(&actions[0], 5);
+    }
+
+    #[test]
+    fn test_hover_test_has_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            #[test]
+            fn foo_<|>test() {}
+            ",
+            &["fn foo_test()"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                Runnable(
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 0..24,
+                            name: "foo_test",
+                            kind: FN_DEF,
+                            focus_range: Some(
+                                11..19,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "foo_test",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg_exprs: [],
+                    },
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_test_mod_has_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            mod tests<|> {
+                #[test]
+                fn foo_test() {}
+            }
+            ",
+            &["mod tests"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                Runnable(
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                1,
+                            ),
+                            full_range: 0..46,
+                            name: "tests",
+                            kind: MODULE,
+                            focus_range: Some(
+                                4..9,
+                            ),
+                            container_name: None,
+                            description: None,
+                            docs: None,
+                        },
+                        kind: TestMod {
+                            path: "tests",
+                        },
+                        cfg_exprs: [],
+                    },
+                ),
+            ]
+            "###);
+    }
 }
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 75bd3c96b..7eb2cef73 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -149,11 +149,10 @@ fn get_param_name_hints(
         ast::Expr::MethodCallExpr(expr) => expr.arg_list()?.args(),
         _ => return None,
     };
-    let args_count = args.clone().count();
 
     let fn_signature = get_fn_signature(sema, &expr)?;
     let n_params_to_skip =
-        if fn_signature.has_self_param && fn_signature.parameter_names.len() > args_count {
+        if fn_signature.has_self_param && matches!(&expr, ast::Expr::MethodCallExpr(_)) {
             1
         } else {
             0
@@ -416,7 +415,7 @@ struct Test<K, T = u8> {
 }
 
 fn main() {
-    let zz = Test { t: 23, k: 33 };
+    let zz = Test { t: 23u8, k: 33 };
     let zz_ref = &zz;
 }"#,
         );
@@ -429,7 +428,7 @@ fn main() {
                 label: "Test<i32>",
             },
             InlayHint {
-                range: 105..111,
+                range: 107..113,
                 kind: TypeHint,
                 label: "&Test<i32>",
             },
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 12d5716e8..28f686767 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -66,7 +66,7 @@ pub use crate::{
     display::{file_structure, FunctionSignature, NavigationTarget, StructureNode},
     expand_macro::ExpandedMacro,
     folding_ranges::{Fold, FoldKind},
-    hover::HoverResult,
+    hover::{HoverAction, HoverConfig, HoverResult},
     inlay_hints::{InlayHint, InlayHintsConfig, InlayKind},
     references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
     runnables::{Runnable, RunnableKind, TestId},
@@ -77,7 +77,7 @@ pub use crate::{
 };
 
 pub use hir::Documentation;
-pub use ra_assists::{AssistConfig, AssistId};
+pub use ra_assists::{Assist, AssistConfig, AssistId, ResolvedAssist};
 pub use ra_db::{
     Canceled, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRootId,
 };
@@ -142,14 +142,6 @@ pub struct AnalysisHost {
     db: RootDatabase,
 }
 
-#[derive(Debug)]
-pub struct Assist {
-    pub id: AssistId,
-    pub label: String,
-    pub group_label: Option<String>,
-    pub source_change: SourceChange,
-}
-
 impl AnalysisHost {
     pub fn new(lru_capacity: Option<usize>) -> AnalysisHost {
         AnalysisHost { db: RootDatabase::new(lru_capacity) }
@@ -470,20 +462,23 @@ impl Analysis {
         self.with_db(|db| completion::completions(db, config, position).map(Into::into))
     }
 
-    /// Computes assists (aka code actions aka intentions) for the given
+    /// Computes resolved assists with source changes for the given position.
+    pub fn resolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<ResolvedAssist>> {
+        self.with_db(|db| ra_assists::Assist::resolved(db, config, frange))
+    }
+
+    /// Computes unresolved assists (aka code actions aka intentions) for the given
     /// position.
-    pub fn assists(&self, config: &AssistConfig, frange: FileRange) -> Cancelable<Vec<Assist>> {
-        self.with_db(|db| {
-            ra_assists::Assist::resolved(db, config, frange)
-                .into_iter()
-                .map(|assist| Assist {
-                    id: assist.assist.id,
-                    label: assist.assist.label,
-                    group_label: assist.assist.group.map(|it| it.0),
-                    source_change: assist.source_change,
-                })
-                .collect()
-        })
+    pub fn unresolved_assists(
+        &self,
+        config: &AssistConfig,
+        frange: FileRange,
+    ) -> Cancelable<Vec<Assist>> {
+        self.with_db(|db| Assist::unresolved(db, config, frange))
     }
 
     /// Computes the set of diagnostics for the given file.
@@ -508,7 +503,7 @@ impl Analysis {
     ) -> Cancelable<Result<SourceChange, SsrError>> {
         self.with_db(|db| {
             let edits = ssr::parse_search_replace(query, parse_only, db)?;
-            Ok(SourceChange::source_file_edits(edits))
+            Ok(SourceChange::from(edits))
         })
     }
 
diff --git a/crates/ra_ide/src/references/rename.rs b/crates/ra_ide/src/references/rename.rs
index 28c6349b1..915d4f4d3 100644
--- a/crates/ra_ide/src/references/rename.rs
+++ b/crates/ra_ide/src/references/rename.rs
@@ -171,7 +171,7 @@ fn rename_to_self(db: &RootDatabase, position: FilePosition) -> Option<RangeInfo
         ),
     });
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edits)))
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn text_edit_from_self_param(
@@ -234,7 +234,7 @@ fn rename_self_to_param(
     let range = ast::SelfParam::cast(self_token.parent())
         .map_or(self_token.text_range(), |p| p.syntax().text_range());
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edits)))
+    Some(RangeInfo::new(range, SourceChange::from(edits)))
 }
 
 fn rename_reference(
@@ -253,7 +253,7 @@ fn rename_reference(
         return None;
     }
 
-    Some(RangeInfo::new(range, SourceChange::source_file_edits(edit)))
+    Some(RangeInfo::new(range, SourceChange::from(edit)))
 }
 
 #[cfg(test)]
diff --git a/crates/ra_ide/src/runnables.rs b/crates/ra_ide/src/runnables.rs
index 286d45eee..fc57dc33d 100644
--- a/crates/ra_ide/src/runnables.rs
+++ b/crates/ra_ide/src/runnables.rs
@@ -1,31 +1,31 @@
+use std::fmt;
+
 use hir::{AsAssocItem, Attrs, HirFileId, InFile, Semantics};
 use itertools::Itertools;
+use ra_cfg::CfgExpr;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
-    ast::{self, AstNode, AttrsOwner, ModuleItemOwner, NameOwner},
-    match_ast, SyntaxNode, TextRange,
+    ast::{self, AstNode, AttrsOwner, DocCommentsOwner, ModuleItemOwner, NameOwner},
+    match_ast, SyntaxNode,
 };
 
-use crate::FileId;
-use ast::DocCommentsOwner;
-use ra_cfg::CfgExpr;
-use std::fmt::Display;
+use crate::{display::ToNav, FileId, NavigationTarget};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Runnable {
-    pub range: TextRange,
+    pub nav: NavigationTarget,
     pub kind: RunnableKind,
     pub cfg_exprs: Vec<CfgExpr>,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum TestId {
     Name(String),
     Path(String),
 }
 
-impl Display for TestId {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+impl fmt::Display for TestId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
             TestId::Name(name) => write!(f, "{}", name),
             TestId::Path(path) => write!(f, "{}", path),
@@ -33,7 +33,7 @@ impl Display for TestId {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum RunnableKind {
     Test { test_id: TestId, attr: TestAttr },
     TestMod { path: String },
@@ -42,6 +42,42 @@ pub enum RunnableKind {
     Bin,
 }
 
+#[derive(Debug, Eq, PartialEq)]
+pub struct RunnableAction {
+    pub run_title: &'static str,
+    pub debugee: bool,
+}
+
+const TEST: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Test", debugee: true };
+const DOCTEST: RunnableAction =
+    RunnableAction { run_title: "▶\u{fe0e} Run Doctest", debugee: false };
+const BENCH: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run Bench", debugee: true };
+const BIN: RunnableAction = RunnableAction { run_title: "▶\u{fe0e} Run", debugee: true };
+
+impl Runnable {
+    // test package::module::testname
+    pub fn label(&self, target: Option<String>) -> String {
+        match &self.kind {
+            RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
+            RunnableKind::TestMod { path } => format!("test-mod {}", path),
+            RunnableKind::Bench { test_id } => format!("bench {}", test_id),
+            RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
+            RunnableKind::Bin => {
+                target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
+            }
+        }
+    }
+
+    pub fn action(&self) -> &'static RunnableAction {
+        match &self.kind {
+            RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => &TEST,
+            RunnableKind::DocTest { .. } => &DOCTEST,
+            RunnableKind::Bench { .. } => &BENCH,
+            RunnableKind::Bin => &BIN,
+        }
+    }
+}
+
 // Feature: Run
 //
 // Shows a popup suggesting to run a test/benchmark/binary **at the current cursor
@@ -59,7 +95,11 @@ pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
     source_file.syntax().descendants().filter_map(|i| runnable(&sema, i, file_id)).collect()
 }
 
-fn runnable(sema: &Semantics<RootDatabase>, item: SyntaxNode, file_id: FileId) -> Option<Runnable> {
+pub(crate) fn runnable(
+    sema: &Semantics<RootDatabase>,
+    item: SyntaxNode,
+    file_id: FileId,
+) -> Option<Runnable> {
     match_ast! {
         match item {
             ast::FnDef(it) => runnable_fn(sema, it, file_id),
@@ -131,10 +171,11 @@ fn runnable_fn(
     let cfg_exprs =
         attrs.by_key("cfg").tt_values().map(|subtree| ra_cfg::parse_cfg(subtree)).collect();
 
-    Some(Runnable { range: fn_def.syntax().text_range(), kind, cfg_exprs })
+    let nav = NavigationTarget::from_named(sema.db, InFile::new(file_id.into(), &fn_def));
+    Some(Runnable { nav, kind, cfg_exprs })
 }
 
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub struct TestAttr {
     pub ignore: bool,
 }
@@ -183,7 +224,6 @@ fn runnable_mod(
     if !has_test_function {
         return None;
     }
-    let range = module.syntax().text_range();
     let module_def = sema.to_def(&module)?;
 
     let path = module_def
@@ -197,7 +237,8 @@ fn runnable_mod(
     let cfg_exprs =
         attrs.by_key("cfg").tt_values().map(|subtree| ra_cfg::parse_cfg(subtree)).collect();
 
-    Some(Runnable { range, kind: RunnableKind::TestMod { path }, cfg_exprs })
+    let nav = module_def.to_nav(sema.db);
+    Some(Runnable { nav, kind: RunnableKind::TestMod { path }, cfg_exprs })
 }
 
 #[cfg(test)]
@@ -206,6 +247,15 @@ mod tests {
 
     use crate::mock_analysis::analysis_and_position;
 
+    use super::{Runnable, RunnableAction, BENCH, BIN, DOCTEST, TEST};
+
+    fn assert_actions(runnables: &[Runnable], actions: &[&RunnableAction]) {
+        assert_eq!(
+            actions,
+            runnables.into_iter().map(|it| it.action()).collect::<Vec<_>>().as_slice()
+        );
+    }
+
     #[test]
     fn test_runnables() {
         let (analysis, pos) = analysis_and_position(
@@ -220,6 +270,9 @@ mod tests {
         #[test]
         #[ignore]
         fn test_foo() {}
+
+        #[bench]
+        fn bench() {}
         "#,
         );
         let runnables = analysis.runnables(pos.file_id).unwrap();
@@ -227,12 +280,38 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..21,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..21,
+                    name: "main",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        12..16,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Bin,
                 cfg_exprs: [],
             },
             Runnable {
-                range: 22..46,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 22..46,
+                    name: "test_foo",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        33..41,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "test_foo",
@@ -244,7 +323,20 @@ mod tests {
                 cfg_exprs: [],
             },
             Runnable {
-                range: 47..81,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 47..81,
+                    name: "test_foo",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        68..76,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "test_foo",
@@ -255,9 +347,32 @@ mod tests {
                 },
                 cfg_exprs: [],
             },
+            Runnable {
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 82..104,
+                    name: "bench",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        94..99,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
+                kind: Bench {
+                    test_id: Path(
+                        "bench",
+                    ),
+                },
+                cfg_exprs: [],
+            },
         ]
         "###
                 );
+        assert_actions(&runnables, &[&BIN, &TEST, &TEST, &BENCH]);
     }
 
     #[test]
@@ -279,12 +394,38 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..21,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..21,
+                    name: "main",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        12..16,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Bin,
                 cfg_exprs: [],
             },
             Runnable {
-                range: 22..64,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 22..64,
+                    name: "foo",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        56..59,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: DocTest {
                     test_id: Path(
                         "foo",
@@ -295,6 +436,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&BIN, &DOCTEST]);
     }
 
     #[test]
@@ -319,12 +461,38 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..21,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..21,
+                    name: "main",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        12..16,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Bin,
                 cfg_exprs: [],
             },
             Runnable {
-                range: 51..105,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 51..105,
+                    name: "foo",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        97..100,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: DocTest {
                     test_id: Path(
                         "Data::foo",
@@ -335,6 +503,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&BIN, &DOCTEST]);
     }
 
     #[test]
@@ -354,14 +523,40 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..59,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..59,
+                    name: "test_mod",
+                    kind: MODULE,
+                    focus_range: Some(
+                        13..21,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: TestMod {
                     path: "test_mod",
                 },
                 cfg_exprs: [],
             },
             Runnable {
-                range: 28..57,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 28..57,
+                    name: "test_foo1",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        43..52,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "test_mod::test_foo1",
@@ -375,6 +570,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&TEST, &TEST]);
     }
 
     #[test]
@@ -396,14 +592,40 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 23..85,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 23..85,
+                    name: "test_mod",
+                    kind: MODULE,
+                    focus_range: Some(
+                        27..35,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: TestMod {
                     path: "foo::test_mod",
                 },
                 cfg_exprs: [],
             },
             Runnable {
-                range: 46..79,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 46..79,
+                    name: "test_foo1",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        65..74,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "foo::test_mod::test_foo1",
@@ -417,6 +639,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&TEST, &TEST]);
     }
 
     #[test]
@@ -440,14 +663,40 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 41..115,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 41..115,
+                    name: "test_mod",
+                    kind: MODULE,
+                    focus_range: Some(
+                        45..53,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: TestMod {
                     path: "foo::bar::test_mod",
                 },
                 cfg_exprs: [],
             },
             Runnable {
-                range: 68..105,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 68..105,
+                    name: "test_foo1",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        91..100,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "foo::bar::test_mod::test_foo1",
@@ -461,6 +710,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&TEST, &TEST]);
     }
 
     #[test]
@@ -479,7 +729,20 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..58,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..58,
+                    name: "test_foo1",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        44..53,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "test_foo1",
@@ -498,6 +761,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&TEST]);
     }
 
     #[test]
@@ -516,7 +780,20 @@ mod tests {
         @r###"
         [
             Runnable {
-                range: 1..80,
+                nav: NavigationTarget {
+                    file_id: FileId(
+                        1,
+                    ),
+                    full_range: 1..80,
+                    name: "test_foo1",
+                    kind: FN_DEF,
+                    focus_range: Some(
+                        66..75,
+                    ),
+                    container_name: None,
+                    description: None,
+                    docs: None,
+                },
                 kind: Test {
                     test_id: Path(
                         "test_foo1",
@@ -543,6 +820,7 @@ mod tests {
         ]
         "###
                 );
+        assert_actions(&runnables, &[&TEST]);
     }
 
     #[test]
diff --git a/crates/ra_ide/src/snapshots/highlight_doctest.html b/crates/ra_ide/src/snapshots/highlight_doctest.html
new file mode 100644
index 000000000..0ae8c7efc
--- /dev/null
+++ b/crates/ra_ide/src/snapshots/highlight_doctest.html
@@ -0,0 +1,71 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+</style>
+<pre><code><span class="keyword">impl</span> <span class="unresolved_reference">Foo</span> {
+    <span class="comment">/// Constructs a new `Foo`.</span>
+    <span class="comment">///</span>
+    <span class="comment">/// # Examples</span>
+    <span class="comment">///</span>
+    <span class="comment">/// ```</span>
+    <span class="comment">/// #</span> <span class="attribute">#![</span><span class="function attribute">allow</span><span class="attribute">(unused_mut)]</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">foo</span>: <span class="unresolved_reference">Foo</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>();
+    <span class="comment">/// ```</span>
+    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="keyword">fn</span> <span class="function declaration">new</span>() -&gt; <span class="unresolved_reference">Foo</span> {
+        <span class="unresolved_reference">Foo</span> { }
+    }
+
+    <span class="comment">/// `bar` method on `Foo`.</span>
+    <span class="comment">///</span>
+    <span class="comment">/// # Examples</span>
+    <span class="comment">///</span>
+    <span class="comment">/// ```</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foo</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>();
+    <span class="comment">///</span>
+    <span class="comment">/// </span><span class="comment">// calls bar on foo</span>
+    <span class="comment">/// </span><span class="macro">assert!</span>(foo.bar());
+    <span class="comment">///</span>
+    <span class="comment">/// </span><span class="comment">/* multi-line
+    </span><span class="comment">/// </span><span class="comment">       comment */</span>
+    <span class="comment">///</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">multi_line_string</span> = <span class="string_literal">"Foo
+    </span><span class="comment">/// </span><span class="string_literal">  bar
+    </span><span class="comment">/// </span><span class="string_literal">         "</span>;
+    <span class="comment">///</span>
+    <span class="comment">/// ```</span>
+    <span class="comment">///</span>
+    <span class="comment">/// ```</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foobar</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>().<span class="unresolved_reference">bar</span>();
+    <span class="comment">/// ```</span>
+    <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration">foo</span>(&<span class="self_keyword">self</span>) -&gt; <span class="builtin_type">bool</span> {
+        <span class="bool_literal">true</span>
+    }
+}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/highlight_injection.html b/crates/ra_ide/src/snapshots/highlight_injection.html
index 68fc589bc..dec06eb51 100644
--- a/crates/ra_ide/src/snapshots/highlight_injection.html
+++ b/crates/ra_ide/src/snapshots/highlight_injection.html
@@ -10,6 +10,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
diff --git a/crates/ra_ide/src/snapshots/highlight_strings.html b/crates/ra_ide/src/snapshots/highlight_strings.html
index 326744361..849eb3b73 100644
--- a/crates/ra_ide/src/snapshots/highlight_strings.html
+++ b/crates/ra_ide/src/snapshots/highlight_strings.html
@@ -10,6 +10,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
@@ -52,6 +54,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">argument</span><span class="format_specifier">}</span><span class="string_literal">"</span>, argument = <span class="string_literal">"test"</span>);   <span class="comment">// =&gt; "test"</span>
     <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">name</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">"</span>, <span class="numeric_literal">1</span>, name = <span class="numeric_literal">2</span>);          <span class="comment">// =&gt; "2 1"</span>
     <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="variable">a</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">c</span><span class="format_specifier">}</span><span class="string_literal"> </span><span class="format_specifier">{</span><span class="variable">b</span><span class="format_specifier">}</span><span class="string_literal">"</span>, a=<span class="string_literal">"a"</span>, b=<span class="char_literal">'b'</span>, c=<span class="numeric_literal">3</span>);  <span class="comment">// =&gt; "a 3 b"</span>
+    <span class="macro">println!</span>(<span class="string_literal">"{{</span><span class="format_specifier">{</span><span class="format_specifier">}</span><span class="string_literal">}}"</span>, <span class="numeric_literal">2</span>);                       <span class="comment">// =&gt; "{2}"</span>
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">1</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>, <span class="numeric_literal">5</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="numeric_literal">1</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="format_specifier">$</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>, <span class="string_literal">"x"</span>);
@@ -61,7 +64,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">^</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">&gt;</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="string_literal">"x"</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">+</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>);
-    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="variable">x</span><span class="string_literal">}!"</span>, <span class="numeric_literal">27</span>);
+    <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">27</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">5</span>);
     <span class="macro">println!</span>(<span class="string_literal">"Hello </span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="numeric_literal">0</span><span class="numeric_literal">5</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, -<span class="numeric_literal">5</span>);
     <span class="macro">println!</span>(<span class="string_literal">"</span><span class="format_specifier">{</span><span class="format_specifier">:</span><span class="format_specifier">#</span><span class="numeric_literal">0</span><span class="numeric_literal">10</span><span class="variable">x</span><span class="format_specifier">}</span><span class="string_literal">!"</span>, <span class="numeric_literal">27</span>);
diff --git a/crates/ra_ide/src/snapshots/highlight_unsafe.html b/crates/ra_ide/src/snapshots/highlight_unsafe.html
new file mode 100644
index 000000000..bd24e6e38
--- /dev/null
+++ b/crates/ra_ide/src/snapshots/highlight_unsafe.html
@@ -0,0 +1,49 @@
+
+<style>
+body                { margin: 0; }
+pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; }
+
+.lifetime           { color: #DFAF8F; font-style: italic; }
+.comment            { color: #7F9F7F; }
+.struct, .enum      { color: #7CB8BB; }
+.enum_variant       { color: #BDE0F3; }
+.string_literal     { color: #CC9393; }
+.field              { color: #94BFF3; }
+.function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
+.parameter          { color: #94BFF3; }
+.text               { color: #DCDCCC; }
+.type               { color: #7CB8BB; }
+.builtin_type       { color: #8CD0D3; }
+.type_param         { color: #DFAF8F; }
+.attribute          { color: #94BFF3; }
+.numeric_literal    { color: #BFEBBF; }
+.bool_literal       { color: #BFE6EB; }
+.macro              { color: #94BFF3; }
+.module             { color: #AFD8AF; }
+.variable           { color: #DCDCCC; }
+.format_specifier   { color: #CC696B; }
+.mutable            { text-decoration: underline; }
+
+.keyword            { color: #F0DFAF; font-weight: bold; }
+.keyword.unsafe     { color: #BC8383; font-weight: bold; }
+.control            { font-style: italic; }
+</style>
+<pre><code><span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_fn</span>() {}
+
+<span class="keyword">struct</span> <span class="struct declaration">HasUnsafeFn</span>;
+
+<span class="keyword">impl</span> <span class="struct">HasUnsafeFn</span> {
+    <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_method</span>(&<span class="self_keyword">self</span>) {}
+}
+
+<span class="keyword">fn</span> <span class="function declaration">main</span>() {
+    <span class="keyword">let</span> <span class="variable declaration">x</span> = &<span class="numeric_literal">5</span> <span class="keyword">as</span> *<span class="keyword">const</span> <span class="builtin_type">usize</span>;
+    <span class="keyword unsafe">unsafe</span> {
+        <span class="function unsafe">unsafe_fn</span>();
+        <span class="struct">HasUnsafeFn</span>.<span class="function unsafe">unsafe_method</span>();
+        <span class="keyword">let</span> <span class="variable declaration">y</span> = <span class="operator unsafe">*</span>(<span class="variable">x</span>);
+        <span class="keyword">let</span> <span class="variable declaration">z</span> = -<span class="variable">x</span>;
+    }
+}</code></pre>
\ No newline at end of file
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 352e35095..33548d43c 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -10,6 +10,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
@@ -82,7 +84,9 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="keyword">let</span> <span class="variable declaration mutable">y</span> = &<span class="keyword">mut</span> <span class="variable mutable">x</span>;
     <span class="keyword">let</span> <span class="variable declaration">z</span> = &<span class="variable mutable">y</span>;
 
-    <span class="variable mutable">y</span>;
+    <span class="keyword">let</span> <span class="struct">Foo</span> { <span class="field">x</span>: <span class="variable declaration">z</span>, <span class="field">y</span> } = <span class="struct">Foo</span> { <span class="field">x</span>: <span class="variable">z</span>, <span class="field">y</span> };
+
+    <span class="variable">y</span>;
 }
 
 <span class="keyword">enum</span> <span class="enum declaration">Option</span>&lt;<span class="type_param declaration">T</span>&gt; {
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index 2a0294f71..1ab06182c 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -10,6 +10,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
diff --git a/crates/ra_ide/src/syntax_highlighting.rs b/crates/ra_ide/src/syntax_highlighting.rs
index 0b53ebe69..ab45c364a 100644
--- a/crates/ra_ide/src/syntax_highlighting.rs
+++ b/crates/ra_ide/src/syntax_highlighting.rs
@@ -1,5 +1,6 @@
 mod tags;
 mod html;
+mod injection;
 #[cfg(test)]
 mod tests;
 
@@ -10,14 +11,14 @@ use ra_ide_db::{
 };
 use ra_prof::profile;
 use ra_syntax::{
-    ast::{self, HasFormatSpecifier, HasQuotes, HasStringValue},
+    ast::{self, HasFormatSpecifier},
     AstNode, AstToken, Direction, NodeOrToken, SyntaxElement,
     SyntaxKind::*,
-    SyntaxToken, TextRange, WalkEvent, T,
+    TextRange, WalkEvent, T,
 };
 use rustc_hash::FxHashMap;
 
-use crate::{call_info::ActiveParameter, Analysis, FileId};
+use crate::FileId;
 
 use ast::FormatSpecifier;
 pub(crate) use html::highlight_as_html;
@@ -123,6 +124,23 @@ pub(crate) fn highlight(
             _ => (),
         }
 
+        // Check for Rust code in documentation
+        match &event {
+            WalkEvent::Leave(NodeOrToken::Node(node)) => {
+                if let Some((doctest, range_mapping, new_comments)) =
+                    injection::extract_doc_comments(node)
+                {
+                    injection::highlight_doc_comment(
+                        doctest,
+                        range_mapping,
+                        new_comments,
+                        &mut stack,
+                    );
+                }
+            }
+            _ => (),
+        }
+
         let element = match event {
             WalkEvent::Enter(it) => it,
             WalkEvent::Leave(_) => continue,
@@ -173,7 +191,7 @@ pub(crate) fn highlight(
 
         if let Some(token) = element.as_token().cloned().and_then(ast::RawString::cast) {
             let expanded = element_to_highlight.as_token().unwrap().clone();
-            if highlight_injection(&mut stack, &sema, token, expanded).is_some() {
+            if injection::highlight_injection(&mut stack, &sema, token, expanded).is_some() {
                 continue;
             }
         }
@@ -259,9 +277,8 @@ impl HighlightedRangeStack {
             let mut parent = prev.pop().unwrap();
             for ele in children {
                 assert!(parent.range.contains_range(ele.range));
-                let mut cloned = parent.clone();
-                parent.range = TextRange::new(parent.range.start(), ele.range.start());
-                cloned.range = TextRange::new(ele.range.end(), cloned.range.end());
+
+                let cloned = Self::intersect(&mut parent, &ele);
                 if !parent.range.is_empty() {
                     prev.push(parent);
                 }
@@ -274,6 +291,62 @@ impl HighlightedRangeStack {
         }
     }
 
+    /// Intersects the `HighlightedRange` `parent` with `child`.
+    /// `parent` is mutated in place, becoming the range before `child`.
+    /// Returns the range (of the same type as `parent`) *after* `child`.
+    fn intersect(parent: &mut HighlightedRange, child: &HighlightedRange) -> HighlightedRange {
+        assert!(parent.range.contains_range(child.range));
+
+        let mut cloned = parent.clone();
+        parent.range = TextRange::new(parent.range.start(), child.range.start());
+        cloned.range = TextRange::new(child.range.end(), cloned.range.end());
+
+        cloned
+    }
+
+    /// Similar to `pop`, but can modify arbitrary prior ranges (where `pop`)
+    /// can only modify the last range currently on the stack.
+    /// Can be used to do injections that span multiple ranges, like the
+    /// doctest injection below.
+    /// If `delete` is set to true, the parent range is deleted instead of
+    /// intersected.
+    ///
+    /// Note that `pop` can be simulated by `pop_and_inject(false)` but the
+    /// latter is computationally more expensive.
+    fn pop_and_inject(&mut self, delete: bool) {
+        let mut children = self.stack.pop().unwrap();
+        let prev = self.stack.last_mut().unwrap();
+        children.sort_by_key(|range| range.range.start());
+        prev.sort_by_key(|range| range.range.start());
+
+        for child in children {
+            if let Some(idx) =
+                prev.iter().position(|parent| parent.range.contains_range(child.range))
+            {
+                let cloned = Self::intersect(&mut prev[idx], &child);
+                let insert_idx = if delete || prev[idx].range.is_empty() {
+                    prev.remove(idx);
+                    idx
+                } else {
+                    idx + 1
+                };
+                prev.insert(insert_idx, child);
+                if !delete && !cloned.range.is_empty() {
+                    prev.insert(insert_idx + 1, cloned);
+                }
+            } else if let Some(_idx) =
+                prev.iter().position(|parent| parent.range.contains(child.range.start()))
+            {
+                unreachable!("child range should be completely contained in parent range");
+            } else {
+                let idx = prev
+                    .binary_search_by_key(&child.range.start(), |range| range.range.start())
+                    .unwrap_or_else(|x| x);
+                prev.insert(idx, child);
+            }
+        }
+    }
+
     fn add(&mut self, range: HighlightedRange) {
         self.stack
             .last_mut()
@@ -363,6 +436,7 @@ fn highlight_element(
                     highlight_name(db, def) | HighlightModifier::Definition
                 }
                 Some(NameClass::ConstReference(def)) => highlight_name(db, def),
+                Some(NameClass::FieldShorthand { .. }) => HighlightTag::Field.into(),
                 None => highlight_name_by_syntax(name) | HighlightModifier::Definition,
             }
         }
@@ -406,6 +480,19 @@ fn highlight_element(
                 _ => h,
             }
         }
+        T![*] => {
+            let prefix_expr = element.parent().and_then(ast::PrefixExpr::cast)?;
+
+            let expr = prefix_expr.expr()?;
+            let ty = sema.type_of_expr(&expr)?;
+            if !ty.is_raw_ptr() {
+                return None;
+            }
+
+            let mut h = Highlight::new(HighlightTag::Operator);
+            h |= HighlightModifier::Unsafe;
+            h
+        }
 
         k if k.is_keyword() => {
             let h = Highlight::new(HighlightTag::Keyword);
@@ -458,7 +545,13 @@ fn highlight_name(db: &RootDatabase, def: Definition) -> Highlight {
         Definition::Field(_) => HighlightTag::Field,
         Definition::ModuleDef(def) => match def {
             hir::ModuleDef::Module(_) => HighlightTag::Module,
-            hir::ModuleDef::Function(_) => HighlightTag::Function,
+            hir::ModuleDef::Function(func) => {
+                let mut h = HighlightTag::Function.into();
+                if func.is_unsafe(db) {
+                    h |= HighlightModifier::Unsafe;
+                }
+                return h;
+            }
             hir::ModuleDef::Adt(hir::Adt::Struct(_)) => HighlightTag::Struct,
             hir::ModuleDef::Adt(hir::Adt::Enum(_)) => HighlightTag::Enum,
             hir::ModuleDef::Adt(hir::Adt::Union(_)) => HighlightTag::Union,
@@ -516,42 +609,3 @@ fn highlight_name_by_syntax(name: ast::Name) -> Highlight {
 
     tag.into()
 }
-
-fn highlight_injection(
-    acc: &mut HighlightedRangeStack,
-    sema: &Semantics<RootDatabase>,
-    literal: ast::RawString,
-    expanded: SyntaxToken,
-) -> Option<()> {
-    let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
-    if !active_parameter.name.starts_with("ra_fixture") {
-        return None;
-    }
-    let value = literal.value()?;
-    let (analysis, tmp_file_id) = Analysis::from_single_file(value);
-
-    if let Some(range) = literal.open_quote_text_range() {
-        acc.add(HighlightedRange {
-            range,
-            highlight: HighlightTag::StringLiteral.into(),
-            binding_hash: None,
-        })
-    }
-
-    for mut h in analysis.highlight(tmp_file_id).unwrap() {
-        if let Some(r) = literal.map_range_up(h.range) {
-            h.range = r;
-            acc.add(h)
-        }
-    }
-
-    if let Some(range) = literal.close_quote_text_range() {
-        acc.add(HighlightedRange {
-            range,
-            highlight: HighlightTag::StringLiteral.into(),
-            binding_hash: None,
-        })
-    }
-
-    Some(())
-}
diff --git a/crates/ra_ide/src/syntax_highlighting/html.rs b/crates/ra_ide/src/syntax_highlighting/html.rs
index edfe61f39..5bada6252 100644
--- a/crates/ra_ide/src/syntax_highlighting/html.rs
+++ b/crates/ra_ide/src/syntax_highlighting/html.rs
@@ -69,6 +69,8 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .string_literal     { color: #CC9393; }
 .field              { color: #94BFF3; }
 .function           { color: #93E0E3; }
+.function.unsafe    { color: #BC8383; }
+.operator.unsafe    { color: #BC8383; }
 .parameter          { color: #94BFF3; }
 .text               { color: #DCDCCC; }
 .type               { color: #7CB8BB; }
diff --git a/crates/ra_ide/src/syntax_highlighting/injection.rs b/crates/ra_ide/src/syntax_highlighting/injection.rs
new file mode 100644
index 000000000..3575a0fc6
--- /dev/null
+++ b/crates/ra_ide/src/syntax_highlighting/injection.rs
@@ -0,0 +1,168 @@
+//! Syntax highlighting injections such as highlighting of documentation tests.
+
+use std::{collections::BTreeMap, convert::TryFrom};
+
+use ast::{HasQuotes, HasStringValue};
+use hir::Semantics;
+use ra_syntax::{ast, AstToken, SyntaxNode, SyntaxToken, TextRange, TextSize};
+use stdx::SepBy;
+
+use crate::{call_info::ActiveParameter, Analysis, HighlightTag, HighlightedRange, RootDatabase};
+
+use super::HighlightedRangeStack;
+
+pub(super) fn highlight_injection(
+    acc: &mut HighlightedRangeStack,
+    sema: &Semantics<RootDatabase>,
+    literal: ast::RawString,
+    expanded: SyntaxToken,
+) -> Option<()> {
+    let active_parameter = ActiveParameter::at_token(&sema, expanded)?;
+    if !active_parameter.name.starts_with("ra_fixture") {
+        return None;
+    }
+    let value = literal.value()?;
+    let (analysis, tmp_file_id) = Analysis::from_single_file(value);
+
+    if let Some(range) = literal.open_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    for mut h in analysis.highlight(tmp_file_id).unwrap() {
+        if let Some(r) = literal.map_range_up(h.range) {
+            h.range = r;
+            acc.add(h)
+        }
+    }
+
+    if let Some(range) = literal.close_quote_text_range() {
+        acc.add(HighlightedRange {
+            range,
+            highlight: HighlightTag::StringLiteral.into(),
+            binding_hash: None,
+        })
+    }
+
+    Some(())
+}
+
+/// Mapping from extracted documentation code to original code
+type RangesMap = BTreeMap<TextSize, TextSize>;
+
+/// Extracts Rust code from documentation comments as well as a mapping from
+/// the extracted source code back to the original source ranges.
+/// Lastly, a vector of new comment highlight ranges (spanning only the
+/// comment prefix) is returned which is used in the syntax highlighting
+/// injection to replace the previous (line-spanning) comment ranges.
+pub(super) fn extract_doc_comments(
+    node: &SyntaxNode,
+) -> Option<(String, RangesMap, Vec<HighlightedRange>)> {
+    // wrap the doctest into function body to get correct syntax highlighting
+    let prefix = "fn doctest() {\n";
+    let suffix = "}\n";
+    // Mapping from extracted documentation code to original code
+    let mut range_mapping: RangesMap = BTreeMap::new();
+    let mut line_start = TextSize::try_from(prefix.len()).unwrap();
+    let mut is_doctest = false;
+    // Replace the original, line-spanning comment ranges by new, only comment-prefix
+    // spanning comment ranges.
+    let mut new_comments = Vec::new();
+    let doctest = node
+        .children_with_tokens()
+        .filter_map(|el| el.into_token().and_then(ast::Comment::cast))
+        .filter(|comment| comment.kind().doc.is_some())
+        .filter(|comment| {
+            if comment.text().contains("```") {
+                is_doctest = !is_doctest;
+                false
+            } else {
+                is_doctest
+            }
+        })
+        .map(|comment| {
+            let prefix_len = comment.prefix().len();
+            let line: &str = comment.text().as_str();
+            let range = comment.syntax().text_range();
+
+            // whitespace after comment is ignored
+            let pos = if let Some(ws) = line.chars().nth(prefix_len).filter(|c| c.is_whitespace()) {
+                prefix_len + ws.len_utf8()
+            } else {
+                prefix_len
+            };
+
+            // lines marked with `#` should be ignored in output, we skip the `#` char
+            let pos = if let Some(ws) = line.chars().nth(pos).filter(|&c| c == '#') {
+                pos + ws.len_utf8()
+            } else {
+                pos
+            };
+
+            range_mapping.insert(line_start, range.start() + TextSize::try_from(pos).unwrap());
+            new_comments.push(HighlightedRange {
+                range: TextRange::new(
+                    range.start(),
+                    range.start() + TextSize::try_from(pos).unwrap(),
+                ),
+                highlight: HighlightTag::Comment.into(),
+                binding_hash: None,
+            });
+            line_start += range.len() - TextSize::try_from(pos).unwrap();
+            line_start += TextSize::try_from('\n'.len_utf8()).unwrap();
+
+            line[pos..].to_owned()
+        })
+        .sep_by("\n")
+        .to_string();
+
+    if doctest.is_empty() {
+        return None;
+    }
+
+    let doctest = format!("{}{}{}", prefix, doctest, suffix);
+    Some((doctest, range_mapping, new_comments))
+}
+
+/// Injection of syntax highlighting of doctests.
+pub(super) fn highlight_doc_comment(
+    text: String,
+    range_mapping: RangesMap,
+    new_comments: Vec<HighlightedRange>,
+    stack: &mut HighlightedRangeStack,
+) {
+    let (analysis, tmp_file_id) = Analysis::from_single_file(text);
+
+    stack.push();
+    for mut h in analysis.highlight(tmp_file_id).unwrap() {
+        // Determine start offset and end offset in case of multi-line ranges
+        let mut start_offset = None;
+        let mut end_offset = None;
+        for (line_start, orig_line_start) in range_mapping.range(..h.range.end()).rev() {
+            if line_start <= &h.range.start() {
+                start_offset.get_or_insert(orig_line_start - line_start);
+                break;
+            } else {
+                end_offset.get_or_insert(orig_line_start - line_start);
+            }
+        }
+        if let Some(start_offset) = start_offset {
+            h.range = TextRange::new(
+                h.range.start() + start_offset,
+                h.range.end() + end_offset.unwrap_or(start_offset),
+            );
+            stack.add(h);
+        }
+    }
+
+    // Inject the comment prefix highlight ranges
+    stack.push();
+    for comment in new_comments {
+        stack.add(comment);
+    }
+    stack.pop_and_inject(false);
+    stack.pop_and_inject(true);
+}
diff --git a/crates/ra_ide/src/syntax_highlighting/tags.rs b/crates/ra_ide/src/syntax_highlighting/tags.rs
index 1514531de..94f466966 100644
--- a/crates/ra_ide/src/syntax_highlighting/tags.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tags.rs
@@ -24,12 +24,14 @@ pub enum HighlightTag {
     Enum,
     EnumVariant,
     Field,
+    FormatSpecifier,
     Function,
     Keyword,
     Lifetime,
     Macro,
     Module,
     NumericLiteral,
+    Operator,
     SelfKeyword,
     SelfType,
     Static,
@@ -41,8 +43,6 @@ pub enum HighlightTag {
     Union,
     Local,
     UnresolvedReference,
-    FormatSpecifier,
-    Operator,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -72,12 +72,14 @@ impl HighlightTag {
             HighlightTag::Enum => "enum",
             HighlightTag::EnumVariant => "enum_variant",
             HighlightTag::Field => "field",
+            HighlightTag::FormatSpecifier => "format_specifier",
             HighlightTag::Function => "function",
             HighlightTag::Keyword => "keyword",
             HighlightTag::Lifetime => "lifetime",
             HighlightTag::Macro => "macro",
             HighlightTag::Module => "module",
             HighlightTag::NumericLiteral => "numeric_literal",
+            HighlightTag::Operator => "operator",
             HighlightTag::SelfKeyword => "self_keyword",
             HighlightTag::SelfType => "self_type",
             HighlightTag::Static => "static",
@@ -89,8 +91,6 @@ impl HighlightTag {
             HighlightTag::Union => "union",
             HighlightTag::Local => "variable",
             HighlightTag::UnresolvedReference => "unresolved_reference",
-            HighlightTag::FormatSpecifier => "format_specifier",
-            HighlightTag::Operator => "operator",
         }
     }
 }
diff --git a/crates/ra_ide/src/syntax_highlighting/tests.rs b/crates/ra_ide/src/syntax_highlighting/tests.rs
index eb43a23da..949bf59a0 100644
--- a/crates/ra_ide/src/syntax_highlighting/tests.rs
+++ b/crates/ra_ide/src/syntax_highlighting/tests.rs
@@ -9,7 +9,7 @@ use crate::{
 
 #[test]
 fn test_highlighting() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 #[derive(Clone, Debug)]
 struct Foo {
@@ -65,6 +65,8 @@ fn main() {
     let y = &mut x;
     let z = &y;
 
+    let Foo { x: z, y } = Foo { x: z, y };
+
     y;
 }
 
@@ -84,17 +86,14 @@ impl<T> Option<T> {
 }
 "#
         .trim(),
+        "crates/ra_ide/src/snapshots/highlighting.html",
+        false,
     );
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlighting.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
 fn test_rainbow_highlighting() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 fn main() {
     let hello = "hello";
@@ -110,12 +109,9 @@ fn bar() {
 }
 "#
         .trim(),
+        "crates/ra_ide/src/snapshots/rainbow_highlighting.html",
+        true,
     );
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/rainbow_highlighting.html");
-    let actual_html = &analysis.highlight_as_html(file_id, true).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
@@ -153,7 +149,7 @@ fn test_ranges() {
 
 #[test]
 fn test_flattening() {
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r##"
 fn fixture(ra_fixture: &str) {}
 
@@ -167,13 +163,9 @@ fn main() {
     );
 }"##
         .trim(),
+        "crates/ra_ide/src/snapshots/highlight_injection.html",
+        false,
     );
-
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlight_injection.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
-    let expected_html = &read_text(&dst_file);
-    fs::write(dst_file, &actual_html).unwrap();
-    assert_eq_text!(expected_html, actual_html);
 }
 
 #[test]
@@ -192,7 +184,7 @@ macro_rules! test {}
 fn test_string_highlighting() {
     // The format string detection is based on macro-expansion,
     // thus, we have to copy the macro definition from `std`
-    let (analysis, file_id) = single_file(
+    check_highlighting(
         r#"
 macro_rules! println {
     ($($arg:tt)*) => ({
@@ -218,6 +210,7 @@ fn main() {
     println!("{argument}", argument = "test");   // => "test"
     println!("{name} {}", 1, name = 2);          // => "2 1"
     println!("{a} {c} {b}", a="a", b='b', c=3);  // => "a 3 b"
+    println!("{{{}}}", 2);                       // => "{2}"
     println!("Hello {:5}!", "x");
     println!("Hello {:1$}!", "x", 5);
     println!("Hello {1:0$}!", 5, "x");
@@ -249,10 +242,96 @@ fn main() {
     println!("{ничоси}", ничоси = 92);
 }"#
         .trim(),
+        "crates/ra_ide/src/snapshots/highlight_strings.html",
+        false,
     );
+}
+
+#[test]
+fn test_unsafe_highlighting() {
+    check_highlighting(
+        r#"
+unsafe fn unsafe_fn() {}
+
+struct HasUnsafeFn;
+
+impl HasUnsafeFn {
+    unsafe fn unsafe_method(&self) {}
+}
+
+fn main() {
+    let x = &5 as *const usize;
+    unsafe {
+        unsafe_fn();
+        HasUnsafeFn.unsafe_method();
+        let y = *(x);
+        let z = -x;
+    }
+}
+"#
+        .trim(),
+        "crates/ra_ide/src/snapshots/highlight_unsafe.html",
+        false,
+    );
+}
+
+#[test]
+fn test_highlight_doctest() {
+    check_highlighting(
+        r#"
+impl Foo {
+    /// Constructs a new `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # #![allow(unused_mut)]
+    /// let mut foo: Foo = Foo::new();
+    /// ```
+    pub const fn new() -> Foo {
+        Foo { }
+    }
+
+    /// `bar` method on `Foo`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let foo = Foo::new();
+    ///
+    /// // calls bar on foo
+    /// assert!(foo.bar());
+    ///
+    /// /* multi-line
+    ///        comment */
+    ///
+    /// let multi_line_string = "Foo
+    ///   bar
+    ///          ";
+    ///
+    /// ```
+    ///
+    /// ```
+    /// let foobar = Foo::new().bar();
+    /// ```
+    pub fn foo(&self) -> bool {
+        true
+    }
+}
+"#
+        .trim(),
+        "crates/ra_ide/src/snapshots/highlight_doctest.html",
+        false,
+    )
+}
 
-    let dst_file = project_dir().join("crates/ra_ide/src/snapshots/highlight_strings.html");
-    let actual_html = &analysis.highlight_as_html(file_id, false).unwrap();
+/// Highlights the code given by the `ra_fixture` argument, renders the
+/// result as HTML, and compares it with the HTML file given as `snapshot`.
+/// Note that the `snapshot` file is overwritten by the rendered HTML.
+fn check_highlighting(ra_fixture: &str, snapshot: &str, rainbow: bool) {
+    let (analysis, file_id) = single_file(ra_fixture);
+    let dst_file = project_dir().join(snapshot);
+    let actual_html = &analysis.highlight_as_html(file_id, rainbow).unwrap();
     let expected_html = &read_text(&dst_file);
     fs::write(dst_file, &actual_html).unwrap();
     assert_eq_text!(expected_html, actual_html);
diff --git a/crates/ra_ide/src/typing.rs b/crates/ra_ide/src/typing.rs
index 67e2c33a0..83776d2b6 100644
--- a/crates/ra_ide/src/typing.rs
+++ b/crates/ra_ide/src/typing.rs
@@ -17,11 +17,13 @@ mod on_enter;
 
 use ra_db::{FilePosition, SourceDatabase};
 use ra_fmt::leading_indent;
-use ra_ide_db::RootDatabase;
+use ra_ide_db::{source_change::SourceFileEdit, RootDatabase};
 use ra_syntax::{
     algo::find_node_at_offset,
     ast::{self, AstToken},
-    AstNode, SourceFile, TextRange, TextSize,
+    AstNode, SourceFile,
+    SyntaxKind::{FIELD_EXPR, METHOD_CALL_EXPR},
+    TextRange, TextSize,
 };
 
 use ra_text_edit::TextEdit;
@@ -47,8 +49,8 @@ pub(crate) fn on_char_typed(
     assert!(TRIGGER_CHARS.contains(char_typed));
     let file = &db.parse(position.file_id).tree();
     assert_eq!(file.syntax().text().char_at(position.offset), Some(char_typed));
-    let text_edit = on_char_typed_inner(file, position.offset, char_typed)?;
-    Some(SourceChange::source_file_edit_from(position.file_id, text_edit))
+    let edit = on_char_typed_inner(file, position.offset, char_typed)?;
+    Some(SourceFileEdit { file_id: position.file_id, edit }.into())
 }
 
 fn on_char_typed_inner(file: &SourceFile, offset: TextSize, char_typed: char) -> Option<TextEdit> {
@@ -98,9 +100,12 @@ fn on_dot_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
     };
     let current_indent_len = TextSize::of(current_indent);
 
+    let parent = whitespace.syntax().parent();
     // Make sure dot is a part of call chain
-    let field_expr = ast::FieldExpr::cast(whitespace.syntax().parent())?;
-    let prev_indent = leading_indent(field_expr.syntax())?;
+    if !matches!(parent.kind(), FIELD_EXPR | METHOD_CALL_EXPR) {
+        return None;
+    }
+    let prev_indent = leading_indent(&parent)?;
     let target_indent = format!("    {}", prev_indent);
     let target_indent_len = TextSize::of(&target_indent);
     if current_indent_len == target_indent_len {
@@ -143,11 +148,11 @@ mod tests {
         })
     }
 
-    fn type_char(char_typed: char, before: &str, after: &str) {
-        let actual = do_type_char(char_typed, before)
+    fn type_char(char_typed: char, ra_fixture_before: &str, ra_fixture_after: &str) {
+        let actual = do_type_char(char_typed, ra_fixture_before)
             .unwrap_or_else(|| panic!("typing `{}` did nothing", char_typed));
 
-        assert_eq_text!(after, &actual);
+        assert_eq_text!(ra_fixture_after, &actual);
     }
 
     fn type_char_noop(char_typed: char, before: &str) {
@@ -249,6 +254,27 @@ fn foo() {
     }
 
     #[test]
+    fn indents_new_chain_call_with_let() {
+        type_char(
+            '.',
+            r#"
+fn main() {
+    let _ = foo
+    <|>
+    bar()
+}
+"#,
+            r#"
+fn main() {
+    let _ = foo
+        .
+    bar()
+}
+"#,
+        );
+    }
+
+    #[test]
     fn indents_continued_chain_call() {
         type_char(
             '.',
diff --git a/crates/ra_ide_db/src/change.rs b/crates/ra_ide_db/src/change.rs
index 8446ef88e..2fc796a85 100644
--- a/crates/ra_ide_db/src/change.rs
+++ b/crates/ra_ide_db/src/change.rs
@@ -16,7 +16,7 @@ use rustc_hash::FxHashMap;
 
 use crate::{
     symbol_index::{SymbolIndex, SymbolsDatabase},
-    DebugData, RootDatabase,
+    RootDatabase,
 };
 
 #[derive(Default)]
@@ -26,7 +26,6 @@ pub struct AnalysisChange {
     files_changed: Vec<(FileId, Arc<String>)>,
     libraries_added: Vec<LibraryData>,
     crate_graph: Option<CrateGraph>,
-    debug_data: DebugData,
 }
 
 impl fmt::Debug for AnalysisChange {
@@ -87,10 +86,6 @@ impl AnalysisChange {
     pub fn set_crate_graph(&mut self, graph: CrateGraph) {
         self.crate_graph = Some(graph);
     }
-
-    pub fn set_debug_root_path(&mut self, source_root_id: SourceRootId, path: String) {
-        self.debug_data.root_paths.insert(source_root_id, path);
-    }
 }
 
 #[derive(Debug)]
@@ -218,8 +213,6 @@ impl RootDatabase {
         if let Some(crate_graph) = change.crate_graph {
             self.set_crate_graph_with_durability(Arc::new(crate_graph), Durability::HIGH)
         }
-
-        Arc::make_mut(&mut self.debug_data).merge(change.debug_data)
     }
 
     fn apply_root_change(&mut self, root_id: SourceRootId, root_change: RootChange) {
@@ -334,6 +327,7 @@ impl RootDatabase {
             hir::db::CrateLangItemsQuery
             hir::db::LangItemQuery
             hir::db::DocumentationQuery
+            hir::db::ImportMapQuery
 
             // InternDatabase
             hir::db::InternFunctionQuery
@@ -369,6 +363,7 @@ impl RootDatabase {
             hir::db::ImplDatumQuery
             hir::db::AssociatedTyValueQuery
             hir::db::TraitSolveQuery
+            hir::db::ReturnTypeImplTraitsQuery
 
             // SymbolsDatabase
             crate::symbol_index::FileSymbolsQuery
diff --git a/crates/ra_ide_db/src/defs.rs b/crates/ra_ide_db/src/defs.rs
index 8b06cbfc5..3ef5e74b6 100644
--- a/crates/ra_ide_db/src/defs.rs
+++ b/crates/ra_ide_db/src/defs.rs
@@ -18,7 +18,7 @@ use ra_syntax::{
 use crate::RootDatabase;
 
 // FIXME: a more precise name would probably be `Symbol`?
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum Definition {
     Macro(MacroDef),
     Field(Field),
@@ -78,10 +78,15 @@ impl Definition {
     }
 }
 
+#[derive(Debug)]
 pub enum NameClass {
     Definition(Definition),
     /// `None` in `if let None = Some(82) {}`
     ConstReference(Definition),
+    FieldShorthand {
+        local: Local,
+        field: Definition,
+    },
 }
 
 impl NameClass {
@@ -89,12 +94,14 @@ impl NameClass {
         match self {
             NameClass::Definition(it) => Some(it),
             NameClass::ConstReference(_) => None,
+            NameClass::FieldShorthand { local, field: _ } => Some(Definition::Local(local)),
         }
     }
 
     pub fn definition(self) -> Definition {
         match self {
             NameClass::Definition(it) | NameClass::ConstReference(it) => it,
+            NameClass::FieldShorthand { local: _, field } => field,
         }
     }
 }
@@ -102,18 +109,14 @@ impl NameClass {
 pub fn classify_name(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<NameClass> {
     let _p = profile("classify_name");
 
-    if let Some(bind_pat) = name.syntax().parent().and_then(ast::BindPat::cast) {
+    let parent = name.syntax().parent()?;
+
+    if let Some(bind_pat) = ast::BindPat::cast(parent.clone()) {
         if let Some(def) = sema.resolve_bind_pat_to_const(&bind_pat) {
             return Some(NameClass::ConstReference(Definition::ModuleDef(def)));
         }
     }
 
-    classify_name_inner(sema, name).map(NameClass::Definition)
-}
-
-fn classify_name_inner(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<Definition> {
-    let parent = name.syntax().parent()?;
-
     match_ast! {
         match parent {
             ast::Alias(it) => {
@@ -123,63 +126,73 @@ fn classify_name_inner(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Opti
                 let name_ref = path_segment.name_ref()?;
                 let name_ref_class = classify_name_ref(sema, &name_ref)?;
 
-                Some(name_ref_class.definition())
+                Some(NameClass::Definition(name_ref_class.definition()))
             },
             ast::BindPat(it) => {
                 let local = sema.to_def(&it)?;
-                Some(Definition::Local(local))
+
+                if let Some(record_field_pat) = it.syntax().parent().and_then(ast::RecordFieldPat::cast) {
+                    if record_field_pat.name_ref().is_none() {
+                        if let Some(field) = sema.resolve_record_field_pat(&record_field_pat) {
+                            let field = Definition::Field(field);
+                            return Some(NameClass::FieldShorthand { local, field });
+                        }
+                    }
+                }
+
+                Some(NameClass::Definition(Definition::Local(local)))
             },
             ast::RecordFieldDef(it) => {
                 let field: hir::Field = sema.to_def(&it)?;
-                Some(Definition::Field(field))
+                Some(NameClass::Definition(Definition::Field(field)))
             },
             ast::Module(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::StructDef(it) => {
                 let def: hir::Struct = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::UnionDef(it) => {
                 let def: hir::Union = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::EnumDef(it) => {
                 let def: hir::Enum = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::TraitDef(it) => {
                 let def: hir::Trait = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::StaticDef(it) => {
                 let def: hir::Static = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::EnumVariant(it) => {
                 let def: hir::EnumVariant = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::FnDef(it) => {
                 let def: hir::Function = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::ConstDef(it) => {
                 let def: hir::Const = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::TypeAliasDef(it) => {
                 let def: hir::TypeAlias = sema.to_def(&it)?;
-                Some(Definition::ModuleDef(def.into()))
+                Some(NameClass::Definition(Definition::ModuleDef(def.into())))
             },
             ast::MacroCall(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::Macro(def))
+                Some(NameClass::Definition(Definition::Macro(def)))
             },
             ast::TypeParam(it) => {
                 let def = sema.to_def(&it)?;
-                Some(Definition::TypeParam(def))
+                Some(NameClass::Definition(Definition::TypeParam(def)))
             },
             _ => None,
         }
diff --git a/crates/ra_ide_db/src/imports_locator.rs b/crates/ra_ide_db/src/imports_locator.rs
index bf0d8db60..fff112e66 100644
--- a/crates/ra_ide_db/src/imports_locator.rs
+++ b/crates/ra_ide_db/src/imports_locator.rs
@@ -1,7 +1,7 @@
 //! This module contains an import search funcionality that is provided to the ra_assists module.
 //! Later, this should be moved away to a separate crate that is accessible from the ra_assists module.
 
-use hir::{MacroDef, ModuleDef, Semantics};
+use hir::{Crate, MacroDef, ModuleDef, Semantics};
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, SyntaxKind::NAME};
 
@@ -11,44 +11,46 @@ use crate::{
     RootDatabase,
 };
 use either::Either;
+use rustc_hash::FxHashSet;
 
 pub struct ImportsLocator<'a> {
     sema: Semantics<'a, RootDatabase>,
+    krate: Crate,
 }
 
 impl<'a> ImportsLocator<'a> {
-    pub fn new(db: &'a RootDatabase) -> Self {
-        Self { sema: Semantics::new(db) }
+    pub fn new(db: &'a RootDatabase, krate: Crate) -> Self {
+        Self { sema: Semantics::new(db), krate }
     }
 
     pub fn find_imports(&mut self, name_to_import: &str) -> Vec<Either<ModuleDef, MacroDef>> {
         let _p = profile("search_for_imports");
         let db = self.sema.db;
 
-        let project_results = {
-            let mut query = Query::new(name_to_import.to_string());
-            query.exact();
-            query.limit(40);
-            symbol_index::world_symbols(db, query)
-        };
-        let lib_results = {
+        // Query dependencies first.
+        let mut candidates: FxHashSet<_> =
+            self.krate.query_external_importables(db, name_to_import).collect();
+
+        // Query the local crate using the symbol index.
+        let local_results = {
             let mut query = Query::new(name_to_import.to_string());
-            query.libs();
             query.exact();
             query.limit(40);
-            symbol_index::world_symbols(db, query)
+            symbol_index::crate_symbols(db, self.krate.into(), query)
         };
 
-        project_results
-            .into_iter()
-            .chain(lib_results.into_iter())
-            .filter_map(|import_candidate| self.get_name_definition(&import_candidate))
-            .filter_map(|name_definition_to_import| match name_definition_to_import {
-                Definition::ModuleDef(module_def) => Some(Either::Left(module_def)),
-                Definition::Macro(macro_def) => Some(Either::Right(macro_def)),
-                _ => None,
-            })
-            .collect()
+        candidates.extend(
+            local_results
+                .into_iter()
+                .filter_map(|import_candidate| self.get_name_definition(&import_candidate))
+                .filter_map(|name_definition_to_import| match name_definition_to_import {
+                    Definition::ModuleDef(module_def) => Some(Either::Left(module_def)),
+                    Definition::Macro(macro_def) => Some(Either::Right(macro_def)),
+                    _ => None,
+                }),
+        );
+
+        candidates.into_iter().collect()
     }
 
     fn get_name_definition(&mut self, import_candidate: &FileSymbol) -> Option<Definition> {
diff --git a/crates/ra_ide_db/src/lib.rs b/crates/ra_ide_db/src/lib.rs
index 1b74e6558..a808de4f1 100644
--- a/crates/ra_ide_db/src/lib.rs
+++ b/crates/ra_ide_db/src/lib.rs
@@ -16,10 +16,10 @@ use std::sync::Arc;
 use hir::db::{AstDatabase, DefDatabase};
 use ra_db::{
     salsa::{self, Database, Durability},
-    Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, RelativePath,
-    SourceDatabase, SourceRootId, Upcast,
+    Canceled, CheckCanceled, CrateId, FileId, FileLoader, FileLoaderDelegate, SourceDatabase,
+    Upcast,
 };
-use rustc_hash::FxHashMap;
+use rustc_hash::FxHashSet;
 
 use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
 
@@ -36,7 +36,6 @@ use crate::{line_index::LineIndex, symbol_index::SymbolsDatabase};
 #[derive(Debug)]
 pub struct RootDatabase {
     runtime: salsa::Runtime<RootDatabase>,
-    pub(crate) debug_data: Arc<DebugData>,
     pub last_gc: crate::wasm_shims::Instant,
     pub last_gc_check: crate::wasm_shims::Instant,
 }
@@ -57,23 +56,12 @@ impl FileLoader for RootDatabase {
     fn file_text(&self, file_id: FileId) -> Arc<String> {
         FileLoaderDelegate(self).file_text(file_id)
     }
-    fn resolve_relative_path(
-        &self,
-        anchor: FileId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_relative_path(anchor, relative_path)
+    fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
+        FileLoaderDelegate(self).resolve_path(anchor, path)
     }
-    fn relevant_crates(&self, file_id: FileId) -> Arc<Vec<CrateId>> {
+    fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
         FileLoaderDelegate(self).relevant_crates(file_id)
     }
-    fn resolve_extern_path(
-        &self,
-        extern_id: ra_db::ExternSourceId,
-        relative_path: &RelativePath,
-    ) -> Option<FileId> {
-        FileLoaderDelegate(self).resolve_extern_path(extern_id, relative_path)
-    }
 }
 
 impl salsa::Database for RootDatabase {
@@ -109,7 +97,6 @@ impl RootDatabase {
             runtime: salsa::Runtime::default(),
             last_gc: crate::wasm_shims::Instant::now(),
             last_gc_check: crate::wasm_shims::Instant::now(),
-            debug_data: Default::default(),
         };
         db.set_crate_graph_with_durability(Default::default(), Durability::HIGH);
         db.set_local_roots_with_durability(Default::default(), Durability::HIGH);
@@ -132,7 +119,6 @@ impl salsa::ParallelDatabase for RootDatabase {
             runtime: self.runtime.snapshot(self),
             last_gc: self.last_gc,
             last_gc_check: self.last_gc_check,
-            debug_data: Arc::clone(&self.debug_data),
         })
     }
 }
@@ -146,14 +132,3 @@ fn line_index(db: &impl LineIndexDatabase, file_id: FileId) -> Arc<LineIndex> {
     let text = db.file_text(file_id);
     Arc::new(LineIndex::new(&*text))
 }
-
-#[derive(Debug, Default, Clone)]
-pub(crate) struct DebugData {
-    pub(crate) root_paths: FxHashMap<SourceRootId, String>,
-}
-
-impl DebugData {
-    pub(crate) fn merge(&mut self, other: DebugData) {
-        self.root_paths.extend(other.root_paths.into_iter());
-    }
-}
diff --git a/crates/ra_ide_db/src/source_change.rs b/crates/ra_ide_db/src/source_change.rs
index e713f4b7e..f40ae8304 100644
--- a/crates/ra_ide_db/src/source_change.rs
+++ b/crates/ra_ide_db/src/source_change.rs
@@ -22,17 +22,6 @@ impl SourceChange {
     ) -> Self {
         SourceChange { source_file_edits, file_system_edits, is_snippet: false }
     }
-
-    /// Creates a new SourceChange with the given label,
-    /// containing only the given `SourceFileEdits`.
-    pub fn source_file_edits(edits: Vec<SourceFileEdit>) -> Self {
-        SourceChange { source_file_edits: edits, file_system_edits: vec![], is_snippet: false }
-    }
-    /// Creates a new SourceChange with the given label
-    /// from the given `FileId` and `TextEdit`
-    pub fn source_file_edit_from(file_id: FileId, edit: TextEdit) -> Self {
-        SourceFileEdit { file_id, edit }.into()
-    }
 }
 
 #[derive(Debug, Clone)]
@@ -43,11 +32,13 @@ pub struct SourceFileEdit {
 
 impl From<SourceFileEdit> for SourceChange {
     fn from(edit: SourceFileEdit) -> SourceChange {
-        SourceChange {
-            source_file_edits: vec![edit],
-            file_system_edits: Vec::new(),
-            is_snippet: false,
-        }
+        vec![edit].into()
+    }
+}
+
+impl From<Vec<SourceFileEdit>> for SourceChange {
+    fn from(source_file_edits: Vec<SourceFileEdit>) -> SourceChange {
+        SourceChange { source_file_edits, file_system_edits: Vec::new(), is_snippet: false }
     }
 }
 
diff --git a/crates/ra_ide_db/src/symbol_index.rs b/crates/ra_ide_db/src/symbol_index.rs
index acc31fe3b..aab918973 100644
--- a/crates/ra_ide_db/src/symbol_index.rs
+++ b/crates/ra_ide_db/src/symbol_index.rs
@@ -29,9 +29,10 @@ use std::{
 };
 
 use fst::{self, Streamer};
+use hir::db::DefDatabase;
 use ra_db::{
     salsa::{self, ParallelDatabase},
-    FileId, SourceDatabaseExt, SourceRootId,
+    CrateId, FileId, SourceDatabaseExt, SourceRootId,
 };
 use ra_syntax::{
     ast::{self, NameOwner},
@@ -110,6 +111,14 @@ fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex>
     Arc::new(SymbolIndex::new(symbols))
 }
 
+/// Need to wrap Snapshot to provide `Clone` impl for `map_with`
+struct Snap(salsa::Snapshot<RootDatabase>);
+impl Clone for Snap {
+    fn clone(&self) -> Snap {
+        Snap(self.0.snapshot())
+    }
+}
+
 // Feature: Workspace Symbol
 //
 // Uses fuzzy-search to find types, modules and functions by name across your
@@ -132,13 +141,7 @@ fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex>
 // | VS Code | kbd:[Ctrl+T]
 // |===
 pub fn world_symbols(db: &RootDatabase, query: Query) -> Vec<FileSymbol> {
-    /// Need to wrap Snapshot to provide `Clone` impl for `map_with`
-    struct Snap(salsa::Snapshot<RootDatabase>);
-    impl Clone for Snap {
-        fn clone(&self) -> Snap {
-            Snap(self.0.snapshot())
-        }
-    }
+    let _p = ra_prof::profile("world_symbols").detail(|| query.query.clone());
 
     let buf: Vec<Arc<SymbolIndex>> = if query.libs {
         let snap = Snap(db.snapshot());
@@ -173,6 +176,33 @@ pub fn world_symbols(db: &RootDatabase, query: Query) -> Vec<FileSymbol> {
     query.search(&buf)
 }
 
+pub fn crate_symbols(db: &RootDatabase, krate: CrateId, query: Query) -> Vec<FileSymbol> {
+    // FIXME(#4842): This now depends on CrateDefMap, why not build the entire symbol index from
+    // that instead?
+
+    let def_map = db.crate_def_map(krate);
+    let mut files = Vec::new();
+    let mut modules = vec![def_map.root];
+    while let Some(module) = modules.pop() {
+        let data = &def_map[module];
+        files.extend(data.origin.file_id());
+        modules.extend(data.children.values());
+    }
+
+    let snap = Snap(db.snapshot());
+
+    #[cfg(not(feature = "wasm"))]
+    let buf = files
+        .par_iter()
+        .map_with(snap, |db, &file_id| db.0.file_symbols(file_id))
+        .collect::<Vec<_>>();
+
+    #[cfg(feature = "wasm")]
+    let buf = files.iter().map(|&file_id| snap.0.file_symbols(file_id)).collect::<Vec<_>>();
+
+    query.search(&buf)
+}
+
 pub fn index_resolve(db: &RootDatabase, name_ref: &ast::NameRef) -> Vec<FileSymbol> {
     let name = name_ref.text();
     let mut query = Query::new(name.to_string());
@@ -298,9 +328,6 @@ impl Query {
         let mut stream = op.union();
         let mut res = Vec::new();
         while let Some((_, indexed_values)) = stream.next() {
-            if res.len() >= self.limit {
-                break;
-            }
             for indexed_value in indexed_values {
                 let symbol_index = &indices[indexed_value.index];
                 let (start, end) = SymbolIndex::map_value_to_range(indexed_value.value);
@@ -312,7 +339,11 @@ impl Query {
                     if self.exact && symbol.name != self.query {
                         continue;
                     }
+
                     res.push(symbol.clone());
+                    if res.len() >= self.limit {
+                        return res;
+                    }
                 }
             }
         }
diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index be0cd5661..293baecf6 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -18,9 +18,10 @@
 //! // fn foo() {}
 //! ```
 //!
-//! After adding a new inline-test, run `cargo collect-tests` to extract
-//! it as a standalone text-fixture into `tests/data/parser/inline`, and
-//! run `cargo test` once to create the "gold" value.
+//! After adding a new inline-test, run `cargo xtask codegen` to
+//! extract it as a standalone text-fixture into
+//! `crates/ra_syntax/test_data/parser/`, and run `cargo test` once to
+//! create the "gold" value.
 //!
 //! Coding convention: rules like `where_clause` always produce either a
 //! node or an error, rules like `opt_where_clause` may produce nothing.
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 67a924de5..97642bc24 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -118,7 +118,22 @@ pub(super) fn maybe_item(p: &mut Parser, m: Marker, flavor: ItemFlavor) -> Resul
         && p.at_contextual_kw("default")
         && (match p.nth(1) {
             T![impl] => true,
-            T![fn] | T![type] => {
+            T![unsafe] => {
+                // test default_unsafe_impl
+                // default unsafe impl Foo {}
+
+                // test default_unsafe_fn
+                // impl T for Foo {
+                //     default unsafe fn foo() {}
+                // }
+                if p.nth(2) == T![impl] || p.nth(2) == T![fn] {
+                    p.bump_remap(T![default]);
+                    p.bump(T![unsafe]);
+                    has_mods = true;
+                }
+                false
+            }
+            T![fn] | T![type] | T![const] => {
                 if let ItemFlavor::Mod = flavor {
                     true
                 } else {
@@ -198,6 +213,9 @@ pub(super) fn maybe_item(p: &mut Parser, m: Marker, flavor: ItemFlavor) -> Resul
         //     default type T = Bar;
         //     default fn foo() {}
         // }
+        T![const] => {
+            consts::const_def(p, m);
+        }
 
         // test unsafe_default_impl
         // unsafe default impl Foo {}
diff --git a/crates/ra_parser/src/grammar/paths.rs b/crates/ra_parser/src/grammar/paths.rs
index 332acc1a0..428aa711e 100644
--- a/crates/ra_parser/src/grammar/paths.rs
+++ b/crates/ra_parser/src/grammar/paths.rs
@@ -3,7 +3,7 @@
 use super::*;
 
 pub(super) const PATH_FIRST: TokenSet =
-    token_set![IDENT, SELF_KW, SUPER_KW, CRATE_KW, COLON, L_ANGLE];
+    token_set![IDENT, T![self], T![super], T![crate], T![:], T![<]];
 
 pub(super) fn is_path_start(p: &Parser) -> bool {
     is_use_path_start(p) || p.at(T![<])
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 68fb2fc73..427c0eb49 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -4,7 +4,7 @@ use super::*;
 
 pub(super) const PATTERN_FIRST: TokenSet = expressions::LITERAL_FIRST
     .union(paths::PATH_FIRST)
-    .union(token_set![BOX_KW, REF_KW, MUT_KW, L_PAREN, L_BRACK, AMP, UNDERSCORE, MINUS, DOT]);
+    .union(token_set![T![box], T![ref], T![mut], T!['('], T!['['], T![&], T![_], T![-], T![.]]);
 
 pub(crate) fn pattern(p: &mut Parser) {
     pattern_r(p, PAT_RECOVERY_SET);
@@ -88,7 +88,9 @@ fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option<CompletedMarker> {
             _ => bind_pat(p, true),
         },
 
-        _ if paths::is_use_path_start(p) => path_or_macro_pat(p),
+        // test type_path_in_pattern
+        // fn main() { let <_>::Foo = (); }
+        _ if paths::is_path_start(p) => path_or_macro_pat(p),
         _ if is_literal_pat_start(p) => literal_pat(p),
 
         T![.] if p.at(T![..]) => dot_dot_pat(p),
@@ -138,7 +140,7 @@ fn literal_pat(p: &mut Parser) -> CompletedMarker {
 //     let Bar(..) = ();
 // }
 fn path_or_macro_pat(p: &mut Parser) -> CompletedMarker {
-    assert!(paths::is_use_path_start(p));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     let kind = match p.current() {
diff --git a/crates/ra_parser/src/grammar/type_params.rs b/crates/ra_parser/src/grammar/type_params.rs
index 50e4900c3..325d566ad 100644
--- a/crates/ra_parser/src/grammar/type_params.rs
+++ b/crates/ra_parser/src/grammar/type_params.rs
@@ -191,10 +191,14 @@ fn where_predicate(p: &mut Parser) {
         }
         _ => {
             // test where_pred_for
-            // fn test<F>()
+            // fn for_trait<F>()
             // where
             //    for<'a> F: Fn(&'a str)
             // { }
+            if p.at(T![for]) {
+                types::for_binder(p);
+            }
+
             types::type_(p);
 
             if p.at(T![:]) {
diff --git a/crates/ra_parser/src/grammar/types.rs b/crates/ra_parser/src/grammar/types.rs
index fe1a039cb..9e8e3bd97 100644
--- a/crates/ra_parser/src/grammar/types.rs
+++ b/crates/ra_parser/src/grammar/types.rs
@@ -216,19 +216,21 @@ pub(super) fn for_binder(p: &mut Parser) {
 
 // test for_type
 // type A = for<'a> fn() -> ();
-// fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
-// fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
-// fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
+// type B = for<'a> unsafe extern "C" fn(&'a ()) -> ();
+// type Obj = for<'a> PartialEq<&'a i32>;
 pub(super) fn for_type(p: &mut Parser) {
     assert!(p.at(T![for]));
     let m = p.start();
     for_binder(p);
     match p.current() {
-        T![fn] | T![unsafe] | T![extern] => fn_pointer_type(p),
-        T![&] => reference_type(p),
-        _ if paths::is_path_start(p) => path_type_(p, false),
-        _ => p.error("expected a path"),
+        T![fn] | T![unsafe] | T![extern] => {}
+        // OK: legacy trait object format
+        _ if paths::is_use_path_start(p) => {}
+        _ => {
+            p.error("expected a function pointer or path");
+        }
     }
+    type_no_bounds(p);
     m.complete(p, FOR_TYPE);
 }
 
diff --git a/crates/ra_proc_macro_srv/Cargo.toml b/crates/ra_proc_macro_srv/Cargo.toml
index bb3003278..582102945 100644
--- a/crates/ra_proc_macro_srv/Cargo.toml
+++ b/crates/ra_proc_macro_srv/Cargo.toml
@@ -22,3 +22,4 @@ cargo_metadata = "0.10.0"
 difference = "2.0.0"
 # used as proc macro test target
 serde_derive = "1.0.106"
+ra_toolchain = { path = "../ra_toolchain" }
diff --git a/crates/ra_proc_macro_srv/src/tests/utils.rs b/crates/ra_proc_macro_srv/src/tests/utils.rs
index 84348b5de..8d85f2d8a 100644
--- a/crates/ra_proc_macro_srv/src/tests/utils.rs
+++ b/crates/ra_proc_macro_srv/src/tests/utils.rs
@@ -2,7 +2,6 @@
 
 use crate::dylib;
 use crate::ProcMacroSrv;
-pub use difference::Changeset as __Changeset;
 use ra_proc_macro::ListMacrosTask;
 use std::str::FromStr;
 use test_utils::assert_eq_text;
@@ -13,7 +12,7 @@ mod fixtures {
 
     // Use current project metadata to get the proc-macro dylib path
     pub fn dylib_path(crate_name: &str, version: &str) -> std::path::PathBuf {
-        let command = Command::new("cargo")
+        let command = Command::new(ra_toolchain::cargo())
             .args(&["check", "--message-format", "json"])
             .output()
             .unwrap()
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index a306ce95f..4b7444039 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -64,7 +64,7 @@ impl Default for CargoConfig {
     fn default() -> Self {
         CargoConfig {
             no_default_features: false,
-            all_features: true,
+            all_features: false,
             features: Vec::new(),
             load_out_dirs_from_check: false,
             target: None,
diff --git a/crates/ra_project_model/src/json_project.rs b/crates/ra_project_model/src/json_project.rs
index b030c8a6a..ee2de4c25 100644
--- a/crates/ra_project_model/src/json_project.rs
+++ b/crates/ra_project_model/src/json_project.rs
@@ -2,9 +2,16 @@
 
 use std::path::PathBuf;
 
-use rustc_hash::{FxHashMap, FxHashSet};
+use rustc_hash::FxHashSet;
 use serde::Deserialize;
 
+/// Roots and crates that compose this Rust project.
+#[derive(Clone, Debug, Deserialize)]
+pub struct JsonProject {
+    pub(crate) roots: Vec<Root>,
+    pub(crate) crates: Vec<Crate>,
+}
+
 /// A root points to the directory which contains Rust crates. rust-analyzer watches all files in
 /// all roots. Roots might be nested.
 #[derive(Clone, Debug, Deserialize)]
@@ -20,8 +27,10 @@ pub struct Crate {
     pub(crate) root_module: PathBuf,
     pub(crate) edition: Edition,
     pub(crate) deps: Vec<Dep>,
-    pub(crate) atom_cfgs: FxHashSet<String>,
-    pub(crate) key_value_cfgs: FxHashMap<String, String>,
+
+    #[serde(default)]
+    pub(crate) cfg: FxHashSet<String>,
+
     pub(crate) out_dir: Option<PathBuf>,
     pub(crate) proc_macro_dylib_path: Option<PathBuf>,
 }
@@ -48,9 +57,39 @@ pub struct Dep {
     pub(crate) name: String,
 }
 
-/// Roots and crates that compose this Rust project.
-#[derive(Clone, Debug, Deserialize)]
-pub struct JsonProject {
-    pub(crate) roots: Vec<Root>,
-    pub(crate) crates: Vec<Crate>,
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn test_crate_deserialization() {
+        let raw_json = json!(    {
+            "crate_id": 2,
+            "root_module": "this/is/a/file/path.rs",
+            "deps": [
+              {
+                "crate": 1,
+                "name": "some_dep_crate"
+              },
+            ],
+            "edition": "2015",
+            "cfg": [
+              "atom_1",
+              "atom_2",
+              "feature=feature_1",
+              "feature=feature_2",
+              "other=value",
+            ],
+
+        });
+
+        let krate: Crate = serde_json::from_value(raw_json).unwrap();
+
+        assert!(krate.cfg.contains(&"atom_1".to_string()));
+        assert!(krate.cfg.contains(&"atom_2".to_string()));
+        assert!(krate.cfg.contains(&"feature=feature_1".to_string()));
+        assert!(krate.cfg.contains(&"feature=feature_2".to_string()));
+        assert!(krate.cfg.contains(&"other=value".to_string()));
+    }
 }
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index a2e9f65ef..cb0e27dce 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -14,7 +14,7 @@ use std::{
 use anyhow::{bail, Context, Result};
 use ra_cfg::CfgOptions;
 use ra_db::{CrateGraph, CrateName, Edition, Env, ExternSource, ExternSourceId, FileId};
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 use serde_json::from_reader;
 
 pub use crate::{
@@ -32,6 +32,12 @@ pub enum ProjectWorkspace {
     Json { project: JsonProject },
 }
 
+impl From<JsonProject> for ProjectWorkspace {
+    fn from(project: JsonProject) -> ProjectWorkspace {
+        ProjectWorkspace::Json { project }
+    }
+}
+
 /// `PackageRoot` describes a package root folder.
 /// Which may be an external dependency, or a member of
 /// the current workspace.
@@ -41,41 +47,45 @@ pub struct PackageRoot {
     path: PathBuf,
     /// Is a member of the current workspace
     is_member: bool,
+    out_dir: Option<PathBuf>,
 }
 impl PackageRoot {
     pub fn new_member(path: PathBuf) -> PackageRoot {
-        Self { path, is_member: true }
+        Self { path, is_member: true, out_dir: None }
     }
     pub fn new_non_member(path: PathBuf) -> PackageRoot {
-        Self { path, is_member: false }
+        Self { path, is_member: false, out_dir: None }
     }
     pub fn path(&self) -> &Path {
         &self.path
     }
+    pub fn out_dir(&self) -> Option<&Path> {
+        self.out_dir.as_deref()
+    }
     pub fn is_member(&self) -> bool {
         self.is_member
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum ProjectRoot {
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
+pub enum ProjectManifest {
     ProjectJson(PathBuf),
     CargoToml(PathBuf),
 }
 
-impl ProjectRoot {
-    pub fn from_manifest_file(path: PathBuf) -> Result<ProjectRoot> {
+impl ProjectManifest {
+    pub fn from_manifest_file(path: PathBuf) -> Result<ProjectManifest> {
         if path.ends_with("rust-project.json") {
-            return Ok(ProjectRoot::ProjectJson(path));
+            return Ok(ProjectManifest::ProjectJson(path));
         }
         if path.ends_with("Cargo.toml") {
-            return Ok(ProjectRoot::CargoToml(path));
+            return Ok(ProjectManifest::CargoToml(path));
         }
         bail!("project root must point to Cargo.toml or rust-project.json: {}", path.display())
     }
 
-    pub fn discover_single(path: &Path) -> Result<ProjectRoot> {
-        let mut candidates = ProjectRoot::discover(path)?;
+    pub fn discover_single(path: &Path) -> Result<ProjectManifest> {
+        let mut candidates = ProjectManifest::discover(path)?;
         let res = match candidates.pop() {
             None => bail!("no projects"),
             Some(it) => it,
@@ -87,12 +97,12 @@ impl ProjectRoot {
         Ok(res)
     }
 
-    pub fn discover(path: &Path) -> io::Result<Vec<ProjectRoot>> {
+    pub fn discover(path: &Path) -> io::Result<Vec<ProjectManifest>> {
         if let Some(project_json) = find_in_parent_dirs(path, "rust-project.json") {
-            return Ok(vec![ProjectRoot::ProjectJson(project_json)]);
+            return Ok(vec![ProjectManifest::ProjectJson(project_json)]);
         }
         return find_cargo_toml(path)
-            .map(|paths| paths.into_iter().map(ProjectRoot::CargoToml).collect());
+            .map(|paths| paths.into_iter().map(ProjectManifest::CargoToml).collect());
 
         fn find_cargo_toml(path: &Path) -> io::Result<Vec<PathBuf>> {
             match find_in_parent_dirs(path, "Cargo.toml") {
@@ -128,16 +138,28 @@ impl ProjectRoot {
                 .collect()
         }
     }
+
+    pub fn discover_all(paths: &[impl AsRef<Path>]) -> Vec<ProjectManifest> {
+        let mut res = paths
+            .iter()
+            .filter_map(|it| ProjectManifest::discover(it.as_ref()).ok())
+            .flatten()
+            .collect::<FxHashSet<_>>()
+            .into_iter()
+            .collect::<Vec<_>>();
+        res.sort();
+        res
+    }
 }
 
 impl ProjectWorkspace {
     pub fn load(
-        root: ProjectRoot,
+        manifest: ProjectManifest,
         cargo_features: &CargoConfig,
         with_sysroot: bool,
     ) -> Result<ProjectWorkspace> {
-        let res = match root {
-            ProjectRoot::ProjectJson(project_json) => {
+        let res = match manifest {
+            ProjectManifest::ProjectJson(project_json) => {
                 let file = File::open(&project_json).with_context(|| {
                     format!("Failed to open json file {}", project_json.display())
                 })?;
@@ -148,7 +170,7 @@ impl ProjectWorkspace {
                     })?,
                 }
             }
-            ProjectRoot::CargoToml(cargo_toml) => {
+            ProjectManifest::CargoToml(cargo_toml) => {
                 let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml, cargo_features)
                     .with_context(|| {
                         format!(
@@ -186,6 +208,7 @@ impl ProjectWorkspace {
                 .map(|pkg| PackageRoot {
                     path: cargo[pkg].root().to_path_buf(),
                     is_member: cargo[pkg].is_member,
+                    out_dir: cargo[pkg].out_dir.clone(),
                 })
                 .chain(sysroot.crates().map(|krate| {
                     PackageRoot::new_non_member(sysroot[krate].root_dir().to_path_buf())
@@ -194,17 +217,6 @@ impl ProjectWorkspace {
         }
     }
 
-    pub fn out_dirs(&self) -> Vec<PathBuf> {
-        match self {
-            ProjectWorkspace::Json { project } => {
-                project.crates.iter().filter_map(|krate| krate.out_dir.as_ref()).cloned().collect()
-            }
-            ProjectWorkspace::Cargo { cargo, sysroot: _ } => {
-                cargo.packages().filter_map(|pkg| cargo[pkg].out_dir.as_ref()).cloned().collect()
-            }
-        }
-    }
-
     pub fn proc_macro_dylib_paths(&self) -> Vec<PathBuf> {
         match self {
             ProjectWorkspace::Json { project } => project
@@ -232,7 +244,7 @@ impl ProjectWorkspace {
 
     pub fn to_crate_graph(
         &self,
-        default_cfg_options: &CfgOptions,
+        target: Option<&str>,
         extern_source_roots: &FxHashMap<PathBuf, ExternSourceId>,
         proc_macro_client: &ProcMacroClient,
         load: &mut dyn FnMut(&Path) -> Option<FileId>,
@@ -251,12 +263,16 @@ impl ProjectWorkspace {
                             json_project::Edition::Edition2018 => Edition::Edition2018,
                         };
                         let cfg_options = {
-                            let mut opts = default_cfg_options.clone();
-                            for name in &krate.atom_cfgs {
-                                opts.insert_atom(name.into());
-                            }
-                            for (key, value) in &krate.key_value_cfgs {
-                                opts.insert_key_value(key.into(), value.into());
+                            let mut opts = CfgOptions::default();
+                            for cfg in &krate.cfg {
+                                match cfg.find('=') {
+                                    None => opts.insert_atom(cfg.into()),
+                                    Some(pos) => {
+                                        let key = &cfg[..pos];
+                                        let value = cfg[pos + 1..].trim_matches('"');
+                                        opts.insert_key_value(key.into(), value.into());
+                                    }
+                                }
                             }
                             opts
                         };
@@ -315,18 +331,13 @@ impl ProjectWorkspace {
                 }
             }
             ProjectWorkspace::Cargo { cargo, sysroot } => {
+                let mut cfg_options = get_rustc_cfg_options(target);
+
                 let sysroot_crates: FxHashMap<_, _> = sysroot
                     .crates()
                     .filter_map(|krate| {
                         let file_id = load(&sysroot[krate].root)?;
 
-                        // Crates from sysroot have `cfg(test)` disabled
-                        let cfg_options = {
-                            let mut opts = default_cfg_options.clone();
-                            opts.remove_atom("test");
-                            opts
-                        };
-
                         let env = Env::default();
                         let extern_source = ExternSource::default();
                         let proc_macro = vec![];
@@ -337,7 +348,7 @@ impl ProjectWorkspace {
                             file_id,
                             Edition::Edition2018,
                             Some(crate_name),
-                            cfg_options,
+                            cfg_options.clone(),
                             env,
                             extern_source,
                             proc_macro,
@@ -368,6 +379,10 @@ impl ProjectWorkspace {
 
                 let mut pkg_to_lib_crate = FxHashMap::default();
                 let mut pkg_crates = FxHashMap::default();
+
+                // Add test cfg for non-sysroot crates
+                cfg_options.insert_atom("test".into());
+
                 // Next, create crates for each package, target pair
                 for pkg in cargo.packages() {
                     let mut lib_tgt = None;
@@ -376,7 +391,7 @@ impl ProjectWorkspace {
                         if let Some(file_id) = load(root) {
                             let edition = cargo[pkg].edition;
                             let cfg_options = {
-                                let mut opts = default_cfg_options.clone();
+                                let mut opts = cfg_options.clone();
                                 for feature in cargo[pkg].features.iter() {
                                     opts.insert_key_value("feature".into(), feature.into());
                                 }
@@ -533,7 +548,7 @@ impl ProjectWorkspace {
     }
 }
 
-pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
+fn get_rustc_cfg_options(target: Option<&str>) -> CfgOptions {
     let mut cfg_options = CfgOptions::default();
 
     // Some nightly-only cfgs, which are required for stdlib
@@ -551,7 +566,7 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
         let mut cmd = Command::new(ra_toolchain::rustc());
         cmd.args(&["--print", "cfg", "-O"]);
         if let Some(target) = target {
-            cmd.args(&["--target", target.as_str()]);
+            cmd.args(&["--target", target]);
         }
         let output = output(cmd)?;
         Ok(String::from_utf8(output.stdout)?)
@@ -573,6 +588,8 @@ pub fn get_rustc_cfg_options(target: Option<&String>) -> CfgOptions {
         Err(e) => log::error!("failed to get rustc cfgs: {:#}", e),
     }
 
+    cfg_options.insert_atom("debug_assertions".into());
+
     cfg_options
 }
 
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 1876afe95..9d02aeef3 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -75,7 +75,7 @@ impl<N> AstChildren<N> {
 impl<N: AstNode> Iterator for AstChildren<N> {
     type Item = N;
     fn next(&mut self) -> Option<N> {
-        self.inner.by_ref().find_map(N::cast)
+        self.inner.find_map(N::cast)
     }
 }
 
@@ -285,6 +285,8 @@ where
     let pred = predicates.next().unwrap();
     let mut bounds = pred.type_bound_list().unwrap().bounds();
 
+    assert!(pred.for_token().is_none());
+    assert!(pred.type_param_list().is_none());
     assert_eq!("T", pred.type_ref().unwrap().syntax().text().to_string());
     assert_bound("Clone", bounds.next());
     assert_bound("Copy", bounds.next());
@@ -322,6 +324,8 @@ where
     let pred = predicates.next().unwrap();
     let mut bounds = pred.type_bound_list().unwrap().bounds();
 
-    assert_eq!("for<'a> F", pred.type_ref().unwrap().syntax().text().to_string());
+    assert!(pred.for_token().is_some());
+    assert_eq!("<'a>", pred.type_param_list().unwrap().syntax().text().to_string());
+    assert_eq!("F", pred.type_ref().unwrap().syntax().text().to_string());
     assert_bound("Fn(&'a str)", bounds.next());
 }
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
index 29eb3fcb9..2ef173a03 100644
--- a/crates/ra_syntax/src/ast/edit.rs
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -579,12 +579,17 @@ pub trait AstNodeEdit: AstNode + Clone + Sized {
         rewriter.rewrite_ast(self)
     }
     #[must_use]
-    fn indent(&self, indent: IndentLevel) -> Self {
-        Self::cast(indent.increase_indent(self.syntax().clone())).unwrap()
+    fn indent(&self, level: IndentLevel) -> Self {
+        Self::cast(level.increase_indent(self.syntax().clone())).unwrap()
     }
     #[must_use]
-    fn dedent(&self, indent: IndentLevel) -> Self {
-        Self::cast(indent.decrease_indent(self.syntax().clone())).unwrap()
+    fn dedent(&self, level: IndentLevel) -> Self {
+        Self::cast(level.decrease_indent(self.syntax().clone())).unwrap()
+    }
+    #[must_use]
+    fn reset_indent(&self) -> Self {
+        let level = IndentLevel::from_node(self.syntax());
+        self.dedent(level)
     }
 }
 
diff --git a/crates/ra_syntax/src/ast/generated/nodes.rs b/crates/ra_syntax/src/ast/generated/nodes.rs
index cb430ca01..58141da11 100644
--- a/crates/ra_syntax/src/ast/generated/nodes.rs
+++ b/crates/ra_syntax/src/ast/generated/nodes.rs
@@ -2052,6 +2052,8 @@ pub struct WherePred {
 }
 impl ast::TypeBoundsOwner for WherePred {}
 impl WherePred {
+    pub fn for_token(&self) -> Option<SyntaxToken> { support::token(&self.syntax, T![for]) }
+    pub fn type_param_list(&self) -> Option<TypeParamList> { support::child(&self.syntax) }
     pub fn lifetime_token(&self) -> Option<SyntaxToken> {
         support::token(&self.syntax, T![lifetime])
     }
@@ -4849,687 +4851,687 @@ impl AstNode for FieldDefList {
     }
 }
 impl std::fmt::Display for NominalDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for GenericParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for GenericArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeRef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ModuleItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AssocItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Expr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Pat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordInnerPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AttrInput {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Stmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SourceFile {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FnDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RetType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for StructDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UnionDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleFieldDefList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleFieldDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumVariantList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EnumVariant {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TraitDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Module {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ItemList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for StaticDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeAliasDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ImplDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for NeverType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PointerType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArrayType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SliceType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ReferenceType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PlaceholderType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FnPointerType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ForType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ImplTraitType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for DynTraitType {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArrayExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LambdaExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for IfExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LoopExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for EffectExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ForExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WhileExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ContinueExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BreakExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Label {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BlockExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ReturnExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for CallExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MethodCallExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for IndexExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for FieldExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AwaitExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TryExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for CastExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RefExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PrefixExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BoxExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RangeExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BinExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Literal {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchExpr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchArmList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchArm {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MatchGuard {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordLit {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordField {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for OrPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParenPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RefPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BoxPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for BindPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PlaceholderPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for DotDotPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SlicePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RangePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LiteralPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldPatList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for RecordFieldPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TupleStructPat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TuplePat {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Visibility {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Name {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for NameRef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroCall {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Attr {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TokenTree {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeParamList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LifetimeParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeBound {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeBoundList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WherePred {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for WhereClause {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Abi {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExprStmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LetStmt {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Condition {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ParamList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for SelfParam {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Param {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseTree {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Alias {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for UseTreeList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternCrateItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ArgList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for Path {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for PathSegment {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeArgList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for TypeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for AssocTypeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for LifetimeArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ConstArg {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroItems {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroStmts {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternItemList {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for ExternBlock {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MetaItem {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
 impl std::fmt::Display for MacroDef {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(self.syntax(), f)
     }
 }
diff --git a/crates/ra_syntax/src/ast/generated/tokens.rs b/crates/ra_syntax/src/ast/generated/tokens.rs
index f91befaac..abadd0b61 100644
--- a/crates/ra_syntax/src/ast/generated/tokens.rs
+++ b/crates/ra_syntax/src/ast/generated/tokens.rs
@@ -11,7 +11,7 @@ pub struct Whitespace {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for Whitespace {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -32,7 +32,7 @@ pub struct Comment {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for Comment {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -53,7 +53,7 @@ pub struct String {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for String {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
@@ -74,7 +74,7 @@ pub struct RawString {
     pub(crate) syntax: SyntaxToken,
 }
 impl std::fmt::Display for RawString {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Display::fmt(&self.syntax, f)
     }
 }
diff --git a/crates/ra_syntax/src/ast/tokens.rs b/crates/ra_syntax/src/ast/tokens.rs
index 3cd6d99c3..2e72d4927 100644
--- a/crates/ra_syntax/src/ast/tokens.rs
+++ b/crates/ra_syntax/src/ast/tokens.rs
@@ -84,7 +84,7 @@ impl Whitespace {
 }
 
 pub struct QuoteOffsets {
-    pub quotes: [TextRange; 2],
+    pub quotes: (TextRange, TextRange),
     pub contents: TextRange,
 }
 
@@ -103,7 +103,7 @@ impl QuoteOffsets {
         let end = TextSize::of(literal);
 
         let res = QuoteOffsets {
-            quotes: [TextRange::new(start, left_quote), TextRange::new(right_quote, end)],
+            quotes: (TextRange::new(start, left_quote), TextRange::new(right_quote, end)),
             contents: TextRange::new(left_quote, right_quote),
         };
         Some(res)
@@ -116,17 +116,17 @@ pub trait HasQuotes: AstToken {
         let offsets = QuoteOffsets::new(text)?;
         let o = self.syntax().text_range().start();
         let offsets = QuoteOffsets {
-            quotes: [offsets.quotes[0] + o, offsets.quotes[1] + o],
+            quotes: (offsets.quotes.0 + o, offsets.quotes.1 + o),
             contents: offsets.contents + o,
         };
         Some(offsets)
     }
     fn open_quote_text_range(&self) -> Option<TextRange> {
-        self.quote_offsets().map(|it| it.quotes[0])
+        self.quote_offsets().map(|it| it.quotes.0)
     }
 
     fn close_quote_text_range(&self) -> Option<TextRange> {
-        self.quote_offsets().map(|it| it.quotes[1])
+        self.quote_offsets().map(|it| it.quotes.1)
     }
 
     fn text_range_between_quotes(&self) -> Option<TextRange> {
@@ -335,16 +335,26 @@ pub trait HasFormatSpecifier: AstToken {
                             }
                             c if c == '_' || c.is_alphabetic() => {
                                 read_identifier(&mut chars, &mut callback);
-                                if chars.peek().and_then(|next| next.1.as_ref().ok()).copied()
-                                    != Some('$')
-                                {
-                                    continue;
-                                }
-                                skip_char_and_emit(
-                                    &mut chars,
-                                    FormatSpecifier::DollarSign,
-                                    &mut callback,
-                                );
+                                // can be either width (indicated by dollar sign, or type in which case
+                                // the next sign has to be `}`)
+                                let next =
+                                    chars.peek().and_then(|next| next.1.as_ref().ok()).copied();
+                                match next {
+                                    Some('$') => skip_char_and_emit(
+                                        &mut chars,
+                                        FormatSpecifier::DollarSign,
+                                        &mut callback,
+                                    ),
+                                    Some('}') => {
+                                        skip_char_and_emit(
+                                            &mut chars,
+                                            FormatSpecifier::Close,
+                                            &mut callback,
+                                        );
+                                        continue;
+                                    }
+                                    _ => continue,
+                                };
                             }
                             _ => {}
                         }
@@ -416,17 +426,11 @@ pub trait HasFormatSpecifier: AstToken {
                         }
                     }
 
-                    let mut cloned = chars.clone().take(2);
-                    let first = cloned.next().and_then(|next| next.1.as_ref().ok()).copied();
-                    let second = cloned.next().and_then(|next| next.1.as_ref().ok()).copied();
-                    if first != Some('}') {
-                        continue;
-                    }
-                    if second == Some('}') {
-                        // Escaped format end specifier, `}}`
+                    if let Some((_, Ok('}'))) = chars.peek() {
+                        skip_char_and_emit(&mut chars, FormatSpecifier::Close, &mut callback);
+                    } else {
                         continue;
                     }
-                    skip_char_and_emit(&mut chars, FormatSpecifier::Close, &mut callback);
                 }
                 _ => {
                     while let Some((_, Ok(next_char))) = chars.peek() {
diff --git a/crates/ra_syntax/src/ast/traits.rs b/crates/ra_syntax/src/ast/traits.rs
index bfc05e08b..a8f2454fd 100644
--- a/crates/ra_syntax/src/ast/traits.rs
+++ b/crates/ra_syntax/src/ast/traits.rs
@@ -83,13 +83,22 @@ pub trait DocCommentsOwner: AstNode {
         CommentIter { iter: self.syntax().children_with_tokens() }
     }
 
+    fn doc_comment_text(&self) -> Option<String> {
+        self.doc_comments().doc_comment_text()
+    }
+}
+
+impl CommentIter {
+    pub fn from_syntax_node(syntax_node: &ast::SyntaxNode) -> CommentIter {
+        CommentIter { iter: syntax_node.children_with_tokens() }
+    }
+
     /// Returns the textual content of a doc comment block as a single string.
     /// That is, strips leading `///` (+ optional 1 character of whitespace),
     /// trailing `*/`, trailing whitespace and then joins the lines.
-    fn doc_comment_text(&self) -> Option<String> {
+    pub fn doc_comment_text(self) -> Option<String> {
         let mut has_comments = false;
         let docs = self
-            .doc_comments()
             .filter(|comment| comment.kind().doc.is_some())
             .map(|comment| {
                 has_comments = true;
diff --git a/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast b/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
index 7c957fdde..48610a5eb 100644
--- a/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
+++ b/crates/ra_syntax/test_data/parser/err/0024_many_type_parens.rast
@@ -180,44 +180,45 @@ [email protected]
       [email protected]
         [email protected]
           [email protected] "("
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected]
-                      [email protected] "for"
-                      [email protected]
-                        [email protected] "<"
-                      [email protected]
-                        [email protected] "\'a"
-                    [email protected] ">"
-                    [email protected] " "
+          [email protected]
+            [email protected] "for"
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "<"
+                  [email protected]
+                    [email protected] "\'a"
+                  [email protected] ">"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
                     [email protected]
                       [email protected]
                         [email protected]
                           [email protected]
                             [email protected] "Trait"
-                  [email protected] "<"
-                  [email protected]
-                    [email protected] "\'a"
-                [email protected] ">"
-                [email protected]
-                  [email protected] ")"
-              [email protected] " "
-              [email protected] "+"
-              [email protected] " "
-              [email protected]
-                [email protected] "("
-                [email protected]
-                  [email protected]
-                    [email protected]
-                      [email protected]
-                        [email protected] "Copy"
-                [email protected] ")"
-            [email protected] ">"
-            [email protected]
-              [email protected] ";"
+                    [email protected] "<"
+                    [email protected]
+                      [email protected] "\'a"
+                  [email protected] ">"
+                  [email protected]
+                    [email protected] ")"
+                [email protected] " "
+                [email protected] "+"
+                [email protected] " "
+                [email protected]
+                  [email protected] "("
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "Copy"
+                  [email protected] ")"
+              [email protected] ">"
+              [email protected]
+                [email protected] ";"
       [email protected] "\n    "
       [email protected]
         [email protected] "let"
@@ -302,13 +303,12 @@ error 146..146: expected expression
 error 147..147: expected SEMICOLON
 error 148..148: expected expression
 error 149..149: expected SEMICOLON
-error 154..154: expected pattern
-error 155..155: expected IN_KW
-error 155..155: expected expression
-error 157..157: expected a block
+error 155..155: expected type
+error 158..158: expected IN_KW
 error 165..165: expected expression
 error 168..168: expected expression
 error 179..179: expected expression
+error 180..180: expected a block
 error 180..180: expected COMMA
 error 180..180: expected expression
 error 180..180: expected R_PAREN
diff --git a/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast b/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
index 568a4cc02..4d6461d1e 100644
--- a/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
+++ b/crates/ra_syntax/test_data/parser/err/0027_incomplere_where_for.rast
@@ -12,17 +12,16 @@ [email protected]
       [email protected] "where"
       [email protected] " "
       [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
     [email protected] "\n"
     [email protected]
       [email protected] "{"
       [email protected] "}"
   [email protected] "\n"
-error 26..26: expected a path
+error 26..26: expected type
 error 26..26: expected colon
diff --git a/crates/ra_syntax/test_data/parser/err/0043_default_const.rast b/crates/ra_syntax/test_data/parser/err/0043_default_const.rast
new file mode 100644
index 000000000..8eb583ef8
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0043_default_const.rast
@@ -0,0 +1,40 @@
+[email protected]
+  [email protected]
+    [email protected] "trait"
+    [email protected] " "
+    [email protected]
+      [email protected] "T"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n  "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "default"
+      [email protected] " "
+      [email protected]
+        [email protected] "const"
+        [email protected] " "
+        [email protected]
+          [email protected] "f"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u8"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "0"
+        [email protected] ";"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+error 19..19: expected BANG
+error 19..19: expected `{`, `[`, `(`
+error 19..19: expected SEMICOLON
diff --git a/crates/ra_syntax/test_data/parser/err/0043_default_const.rs b/crates/ra_syntax/test_data/parser/err/0043_default_const.rs
new file mode 100644
index 000000000..80f15474a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0043_default_const.rs
@@ -0,0 +1,3 @@
+trait T {
+  default const f: u8 = 0;
+}
diff --git a/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast
new file mode 100644
index 000000000..cb90f28bc
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rast
@@ -0,0 +1,240 @@
+[email protected]
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForRef"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "&"
+        [email protected] "\'a"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u32"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForTup"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "("
+        [email protected]
+          [email protected] "&"
+          [email protected] "\'a"
+          [email protected] " "
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "u32"
+        [email protected] ","
+        [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForSlice"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "["
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u32"
+        [email protected] "]"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "ForForFn"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'b"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "fn"
+          [email protected]
+            [email protected] "("
+            [email protected]
+              [email protected]
+                [email protected] "&"
+                [email protected] "\'a"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "i32"
+            [email protected] ","
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected] "&"
+                [email protected] "\'b"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "i32"
+            [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_for_for"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "for"
+          [email protected]
+            [email protected] "<"
+            [email protected]
+              [email protected] "\'b"
+            [email protected] ">"
+          [email protected] " "
+          [email protected]
+            [email protected] "for"
+            [email protected]
+              [email protected] "<"
+              [email protected]
+                [email protected] "\'c"
+              [email protected] ">"
+            [email protected] " "
+            [email protected]
+              [email protected] "fn"
+              [email protected]
+                [email protected] "("
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'a"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ","
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'b"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ","
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected] "&"
+                    [email protected] "\'c"
+                    [email protected] " "
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected]
+                            [email protected] "T"
+                [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Copy"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+error 21..21: expected a function pointer or path
+error 52..52: expected a function pointer or path
+error 88..88: expected a function pointer or path
+error 119..119: expected a function pointer or path
+error 195..195: expected a function pointer or path
diff --git a/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs
new file mode 100644
index 000000000..0e9f8ccb4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/err/0044_unexpected_for_type.rs
@@ -0,0 +1,9 @@
+type ForRef = for<'a> &'a u32;
+type ForTup = for<'a> (&'a u32,);
+type ForSlice = for<'a> [u32];
+type ForForFn = for<'a> for<'b> fn(&'a i32, &'b i32);
+fn for_for_for<T>()
+where
+    for<'a> for<'b> for<'c> fn(&'a T, &'b T, &'c T): Copy,
+{
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast b/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
index 9be441110..53f7ebaf9 100644
--- a/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
+++ b/crates/ra_syntax/test_data/parser/inline/err/0010_wrong_order_fns.rast
@@ -17,23 +17,29 @@ [email protected]
       [email protected] "{"
       [email protected] "}"
   [email protected] "\n"
-  ERROR@25..31
+  CONST_DEF@25..46
     [email protected] "unsafe"
-  [email protected] " "
-  [email protected]
+    [email protected] " "
     [email protected] "const"
     [email protected] " "
-    [email protected] "fn"
+    [email protected]
+      [email protected] "fn"
     [email protected] " "
-    [email protected]
-      [email protected] "bar"
-    [email protected]
-      [email protected] "("
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "bar"
+          [email protected]
+            [email protected] "("
+            [email protected] ")"
+  [email protected] " "
+  [email protected]
+    [email protected] "{"
+    [email protected] "}"
   [email protected] "\n"
 error 6..6: expected existential, fn, trait or impl
-error 31..31: expected existential, fn, trait or impl
+error 38..38: expected a name
+error 40..40: expected COLON
+error 46..46: expected SEMICOLON
+error 47..47: expected an item
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
index 9dc473e43..cd0892451 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rast
@@ -1,61 +1,60 @@
-[email protected]9
-  FN_DEF@0..48
+SOURCE_FILE@0..54
+  FN_DEF@0..53
     [email protected] "fn"
     [email protected] " "
-    [email protected]
-      [email protected] "test"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "F"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected] ")"
-    [email protected] "\n"
-    [email protected]
-      [email protected] "where"
-      [email protected] "\n   "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "F"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Fn"
-                  [email protected]
-                    [email protected] "("
-                    [email protected]
-                      [email protected]
-                        [email protected] "&"
-                        [email protected] "\'a"
-                        [email protected] " "
-                        [email protected]
-                          [email protected]
-                            [email protected]
-                              [email protected]
-                                [email protected] "str"
-                    [email protected] ")"
-    [email protected] "\n"
-    [email protected]
-      [email protected] "{"
-      [email protected] " "
-      [email protected] "}"
-  [email protected] "\n"
+    [email protected]
+      [email protected] "for_trait"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n   "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
index b448c6178..423bc105b 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0003_where_pred_for.rs
@@ -1,4 +1,4 @@
-fn test<F>()
+fn for_trait<F>()
 where
    for<'a> F: Fn(&'a str)
 { }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
index dfb8d57ad..b26ac2d36 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rast
@@ -1,4 +1,4 @@
-[email protected]00
+SOURCE_FILE@0..121
   [email protected]
     [email protected] "type"
     [email protected] " "
@@ -29,212 +29,84 @@ [email protected]
             [email protected] ")"
     [email protected] ";"
   [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "foo"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected] "&"
-            [email protected] "\'a"
-            [email protected] " "
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "T"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "bar"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected] "&"
-            [email protected] "\'a"
-            [email protected] " "
-            [email protected] "mut"
-            [email protected] " "
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "T"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
-  [email protected]
-    [email protected] "fn"
-    [email protected] " "
-    [email protected]
-      [email protected] "baz"
-    [email protected]
-      [email protected] "<"
-      [email protected]
-        [email protected]
-          [email protected] "T"
-      [email protected] ">"
-    [email protected]
-      [email protected] "("
-      [email protected]
-        [email protected]
-          [email protected]
-            [email protected] "_t"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected] "&"
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "T"
-      [email protected] ")"
-    [email protected] " "
-    [email protected]
-      [email protected] "where"
-      [email protected] " "
-      [email protected]
-        [email protected]
-          [email protected] "for"
-          [email protected]
-            [email protected] "<"
-            [email protected]
-              [email protected] "\'a"
-            [email protected] ">"
-          [email protected] " "
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected] "<"
-                  [email protected]
-                    [email protected] "&"
-                    [email protected] "\'a"
-                    [email protected] " "
-                    [email protected]
-                      [email protected]
-                        [email protected]
-                          [email protected]
-                            [email protected] "T"
-                  [email protected] " "
-                  [email protected] "as"
-                  [email protected] " "
-                  [email protected]
-                    [email protected]
-                      [email protected]
-                        [email protected]
-                          [email protected] "Baz"
-                  [email protected] ">"
-              [email protected] "::"
-              [email protected]
-                [email protected]
-                  [email protected] "Foo"
-        [email protected] ":"
-        [email protected] " "
-        [email protected]
-          [email protected]
-            [email protected]
-              [email protected]
-                [email protected]
-                  [email protected]
-                    [email protected] "Iterator"
-    [email protected] " "
-    [email protected]
-      [email protected] "{"
-      [email protected] "}"
-  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "B"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected] "unsafe"
+        [email protected] " "
+        [email protected]
+          [email protected] "extern"
+          [email protected] " "
+          [email protected] "\"C\""
+        [email protected] " "
+        [email protected] "fn"
+        [email protected]
+          [email protected] "("
+          [email protected]
+            [email protected]
+              [email protected] "&"
+              [email protected] "\'a"
+              [email protected] " "
+              [email protected]
+                [email protected] "("
+                [email protected] ")"
+          [email protected] ")"
+        [email protected] " "
+        [email protected]
+          [email protected] "->"
+          [email protected] " "
+          [email protected]
+            [email protected] "("
+            [email protected] ")"
+    [email protected] ";"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "type"
+    [email protected] " "
+    [email protected]
+      [email protected] "Obj"
+    [email protected] " "
+    [email protected] "="
+    [email protected] " "
+    [email protected]
+      [email protected] "for"
+      [email protected]
+        [email protected] "<"
+        [email protected]
+          [email protected] "\'a"
+        [email protected] ">"
+      [email protected] " "
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected] "PartialEq"
+            [email protected]
+              [email protected] "<"
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "i32"
+              [email protected] ">"
+    [email protected] ";"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
index d6774d438..8ac7b9e10 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
@@ -1,4 +1,3 @@
 type A = for<'a> fn() -> ();
-fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
-fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
-fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
+type B = for<'a> unsafe extern "C" fn(&'a ()) -> ();
+type Obj = for<'a> PartialEq<&'a i32>;
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast
new file mode 100644
index 000000000..adb6159f4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rast
@@ -0,0 +1,40 @@
+[email protected]
+  [email protected]
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "T"
+    [email protected] " "
+    [email protected] "for"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "default"
+        [email protected] " "
+        [email protected] "unsafe"
+        [email protected] " "
+        [email protected] "fn"
+        [email protected] " "
+        [email protected]
+          [email protected] "foo"
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+        [email protected] " "
+        [email protected]
+          [email protected] "{"
+          [email protected] "}"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs
new file mode 100644
index 000000000..12926cd8a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_fn.rs
@@ -0,0 +1,3 @@
+impl T for Foo {
+    default unsafe fn foo() {}
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast
new file mode 100644
index 000000000..a9eda5668
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rast
@@ -0,0 +1,18 @@
+[email protected]
+  [email protected]
+    [email protected] "default"
+    [email protected] " "
+    [email protected] "unsafe"
+    [email protected] " "
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs
new file mode 100644
index 000000000..ba0998ff4
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0163_default_unsafe_impl.rs
@@ -0,0 +1 @@
+default unsafe impl Foo {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast
new file mode 100644
index 000000000..868899275
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rast
@@ -0,0 +1,38 @@
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "main"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] " "
+      [email protected]
+        [email protected] "let"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "<"
+                [email protected]
+                  [email protected] "_"
+                [email protected] ">"
+            [email protected] "::"
+            [email protected]
+              [email protected]
+                [email protected] "Foo"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "("
+          [email protected] ")"
+        [email protected] ";"
+      [email protected] " "
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs
new file mode 100644
index 000000000..ebe26834d
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0164_type_path_in_pattern.rs
@@ -0,0 +1 @@
+fn main() { let <_>::Foo = (); }
diff --git a/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast
new file mode 100644
index 000000000..dab0247ee
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rast
@@ -0,0 +1,44 @@
+[email protected]
+  [email protected]
+    [email protected] "impl"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "T"
+    [email protected] " "
+    [email protected] "for"
+    [email protected] " "
+    [email protected]
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "Foo"
+    [email protected] " "
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n  "
+      [email protected]
+        [email protected] "default"
+        [email protected] " "
+        [email protected] "const"
+        [email protected] " "
+        [email protected]
+          [email protected] "f"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "u8"
+        [email protected] " "
+        [email protected] "="
+        [email protected] " "
+        [email protected]
+          [email protected] "0"
+        [email protected] ";"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs
new file mode 100644
index 000000000..dfb3b92dc
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0066_default_const.rs
@@ -0,0 +1,3 @@
+impl T for Foo {
+  default const f: u8 = 0;
+}
diff --git a/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast
new file mode 100644
index 000000000..503585103
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rast
@@ -0,0 +1,392 @@
+[email protected]
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_trait"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_ref"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "&"
+          [email protected] "\'a"
+          [email protected] " "
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "F"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Debug"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_parens"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "("
+          [email protected]
+            [email protected] "&"
+            [email protected] "\'a"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "F"
+          [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Fn"
+                  [email protected]
+                    [email protected] "("
+                    [email protected]
+                      [email protected]
+                        [email protected] "&"
+                        [email protected] "\'a"
+                        [email protected] " "
+                        [email protected]
+                          [email protected]
+                            [email protected]
+                              [email protected]
+                                [email protected] "str"
+                    [email protected] ")"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_slice"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "F"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "["
+          [email protected]
+            [email protected] "&"
+            [email protected] "\'a"
+            [email protected] " "
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "F"
+          [email protected] "]"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Eq"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_qpath"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected]
+        [email protected]
+          [email protected]
+            [email protected] "_t"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected] "&"
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected] "T"
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected] "<"
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+                [email protected] " "
+                [email protected] "as"
+                [email protected] " "
+                [email protected]
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected] "Baz"
+                [email protected] ">"
+            [email protected] "::"
+            [email protected]
+              [email protected]
+                [email protected] "Foo"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Iterator"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
+  [email protected]
+    [email protected] "fn"
+    [email protected] " "
+    [email protected]
+      [email protected] "for_for_fn"
+    [email protected]
+      [email protected] "<"
+      [email protected]
+        [email protected]
+          [email protected] "T"
+      [email protected] ">"
+    [email protected]
+      [email protected] "("
+      [email protected] ")"
+    [email protected] "\n"
+    [email protected]
+      [email protected] "where"
+      [email protected] "\n    "
+      [email protected]
+        [email protected] "for"
+        [email protected]
+          [email protected] "<"
+          [email protected]
+            [email protected] "\'a"
+          [email protected] ">"
+        [email protected] " "
+        [email protected]
+          [email protected] "for"
+          [email protected]
+            [email protected] "<"
+            [email protected]
+              [email protected] "\'b"
+            [email protected] ">"
+          [email protected] " "
+          [email protected]
+            [email protected] "fn"
+            [email protected]
+              [email protected] "("
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'a"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+              [email protected] ","
+              [email protected] " "
+              [email protected]
+                [email protected]
+                  [email protected] "&"
+                  [email protected] "\'b"
+                  [email protected] " "
+                  [email protected]
+                    [email protected]
+                      [email protected]
+                        [email protected]
+                          [email protected] "T"
+              [email protected] ")"
+        [email protected] ":"
+        [email protected] " "
+        [email protected]
+          [email protected]
+            [email protected]
+              [email protected]
+                [email protected]
+                  [email protected]
+                    [email protected] "Copy"
+      [email protected] ","
+    [email protected] "\n"
+    [email protected]
+      [email protected] "{"
+      [email protected] "\n"
+      [email protected] "}"
+  [email protected] "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs
new file mode 100644
index 000000000..9058c4619
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0067_where_for_pred.rs
@@ -0,0 +1,30 @@
+fn for_trait<F>()
+where
+    for<'a> F: Fn(&'a str),
+{
+}
+fn for_ref<F>()
+where
+    for<'a> &'a F: Debug,
+{
+}
+fn for_parens<F>()
+where
+    for<'a> (&'a F): Fn(&'a str),
+{
+}
+fn for_slice<F>()
+where
+    for<'a> [&'a F]: Eq,
+{
+}
+fn for_qpath<T>(_t: &T)
+where
+    for<'a> <&'a T as Baz>::Foo: Iterator,
+{
+}
+fn for_for_fn<T>()
+where
+    for<'a> for<'b> fn(&'a T, &'b T): Copy,
+{
+}
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 65b487db3..458089e53 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -10,7 +10,7 @@ doctest = false
 
 [[bin]]
 name = "rust-analyzer"
-path = "./src/bin/main.rs"
+path = "src/bin/main.rs"
 
 [dependencies]
 anyhow = "1.0.26"
@@ -32,7 +32,7 @@ threadpool = "1.7.1"
 
 stdx = { path = "../stdx" }
 
-lsp-server = "0.3.1"
+lsp-server = "0.3.2"
 ra_flycheck = { path = "../ra_flycheck" }
 ra_ide = { path = "../ra_ide" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/rust-analyzer/src/bin/main.rs b/crates/rust-analyzer/src/bin/main.rs
index e82fd57de..8d071ab1c 100644
--- a/crates/rust-analyzer/src/bin/main.rs
+++ b/crates/rust-analyzer/src/bin/main.rs
@@ -4,9 +4,14 @@
 mod args;
 
 use lsp_server::Connection;
-use rust_analyzer::{cli, config::Config, from_json, Result};
+use rust_analyzer::{
+    cli,
+    config::{Config, LinkedProject},
+    from_json, Result,
+};
 
 use crate::args::HelpPrinted;
+use ra_project_model::ProjectManifest;
 
 fn main() -> Result<()> {
     setup_logging()?;
@@ -97,17 +102,6 @@ fn run_server() -> Result<()> {
         log::info!("Client '{}' {}", client_info.name, client_info.version.unwrap_or_default());
     }
 
-    let cwd = std::env::current_dir()?;
-    let root = initialize_params.root_uri.and_then(|it| it.to_file_path().ok()).unwrap_or(cwd);
-
-    let workspace_roots = initialize_params
-        .workspace_folders
-        .map(|workspaces| {
-            workspaces.into_iter().filter_map(|it| it.uri.to_file_path().ok()).collect::<Vec<_>>()
-        })
-        .filter(|workspaces| !workspaces.is_empty())
-        .unwrap_or_else(|| vec![root]);
-
     let config = {
         let mut config = Config::default();
         if let Some(value) = &initialize_params.initialization_options {
@@ -115,10 +109,31 @@ fn run_server() -> Result<()> {
         }
         config.update_caps(&initialize_params.capabilities);
 
+        if config.linked_projects.is_empty() {
+            let cwd = std::env::current_dir()?;
+            let root =
+                initialize_params.root_uri.and_then(|it| it.to_file_path().ok()).unwrap_or(cwd);
+            let workspace_roots = initialize_params
+                .workspace_folders
+                .map(|workspaces| {
+                    workspaces
+                        .into_iter()
+                        .filter_map(|it| it.uri.to_file_path().ok())
+                        .collect::<Vec<_>>()
+                })
+                .filter(|workspaces| !workspaces.is_empty())
+                .unwrap_or_else(|| vec![root]);
+
+            config.linked_projects = ProjectManifest::discover_all(&workspace_roots)
+                .into_iter()
+                .map(LinkedProject::from)
+                .collect();
+        }
+
         config
     };
 
-    rust_analyzer::main_loop(workspace_roots, config, connection)?;
+    rust_analyzer::main_loop(config, connection)?;
 
     log::info!("shutting down IO...");
     io_threads.join()?;
diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index 345693524..673795e78 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -87,6 +87,9 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
             "ssr": true,
             "onEnter": true,
             "parentModule": true,
+            "runnables": {
+                "kinds": [ "cargo" ],
+            },
         })),
     }
 }
diff --git a/crates/rust-analyzer/src/cargo_target_spec.rs b/crates/rust-analyzer/src/cargo_target_spec.rs
index 441fb61df..44f856f6b 100644
--- a/crates/rust-analyzer/src/cargo_target_spec.rs
+++ b/crates/rust-analyzer/src/cargo_target_spec.rs
@@ -1,10 +1,10 @@
 //! See `CargoTargetSpec`
 
+use ra_cfg::CfgExpr;
 use ra_ide::{FileId, RunnableKind, TestId};
 use ra_project_model::{self, ProjectWorkspace, TargetKind};
 
-use crate::{world::WorldSnapshot, Result};
-use ra_syntax::SmolStr;
+use crate::{global_state::GlobalStateSnapshot, Result};
 
 /// Abstract representation of Cargo target.
 ///
@@ -21,7 +21,7 @@ impl CargoTargetSpec {
     pub(crate) fn runnable_args(
         spec: Option<CargoTargetSpec>,
         kind: &RunnableKind,
-        features_needed: &Vec<SmolStr>,
+        cfgs: &[CfgExpr],
     ) -> Result<(Vec<String>, Vec<String>)> {
         let mut args = Vec::new();
         let mut extra_args = Vec::new();
@@ -76,16 +76,20 @@ impl CargoTargetSpec {
             }
         }
 
-        features_needed.iter().for_each(|feature| {
+        let mut features = Vec::new();
+        for cfg in cfgs {
+            required_features(cfg, &mut features);
+        }
+        for feature in features {
             args.push("--features".to_string());
-            args.push(feature.to_string());
-        });
+            args.push(feature);
+        }
 
         Ok((args, extra_args))
     }
 
     pub(crate) fn for_file(
-        world: &WorldSnapshot,
+        world: &GlobalStateSnapshot,
         file_id: FileId,
     ) -> Result<Option<CargoTargetSpec>> {
         let &crate_id = match world.analysis().crate_for(file_id)?.first() {
@@ -140,3 +144,74 @@ impl CargoTargetSpec {
         }
     }
 }
+
+/// Fill minimal features needed
+fn required_features(cfg_expr: &CfgExpr, features: &mut Vec<String>) {
+    match cfg_expr {
+        CfgExpr::KeyValue { key, value } if key == "feature" => features.push(value.to_string()),
+        CfgExpr::All(preds) => {
+            preds.iter().for_each(|cfg| required_features(cfg, features));
+        }
+        CfgExpr::Any(preds) => {
+            for cfg in preds {
+                let len_features = features.len();
+                required_features(cfg, features);
+                if len_features != features.len() {
+                    break;
+                }
+            }
+        }
+        _ => {}
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use mbe::{ast_to_token_tree, TokenMap};
+    use ra_cfg::parse_cfg;
+    use ra_syntax::{
+        ast::{self, AstNode},
+        SmolStr,
+    };
+
+    fn get_token_tree_generated(input: &str) -> (tt::Subtree, TokenMap) {
+        let source_file = ast::SourceFile::parse(input).ok().unwrap();
+        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+        ast_to_token_tree(&tt).unwrap()
+    }
+
+    #[test]
+    fn test_cfg_expr_minimal_features_needed() {
+        let (subtree, _) = get_token_tree_generated(r#"#![cfg(feature = "baz")]"#);
+        let cfg_expr = parse_cfg(&subtree);
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+
+        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+
+        let (subtree, _) =
+            get_token_tree_generated(r#"#![cfg(all(feature = "baz", feature = "foo"))]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert_eq!(min_features, vec![SmolStr::new("baz"), SmolStr::new("foo")]);
+
+        let (subtree, _) =
+            get_token_tree_generated(r#"#![cfg(any(feature = "baz", feature = "foo", unix))]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+
+        let (subtree, _) = get_token_tree_generated(r#"#![cfg(foo)]"#);
+        let cfg_expr = parse_cfg(&subtree);
+
+        let mut min_features = vec![];
+        required_features(&cfg_expr, &mut min_features);
+        assert!(min_features.is_empty());
+    }
+}
diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index 8eaf75ff6..97367d7c6 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -8,7 +8,7 @@ use crossbeam_channel::{unbounded, Receiver};
 use ra_db::{ExternSourceId, FileId, SourceRootId};
 use ra_ide::{AnalysisChange, AnalysisHost};
 use ra_project_model::{
-    get_rustc_cfg_options, CargoConfig, PackageRoot, ProcMacroClient, ProjectRoot, ProjectWorkspace,
+    CargoConfig, PackageRoot, ProcMacroClient, ProjectManifest, ProjectWorkspace,
 };
 use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -28,7 +28,7 @@ pub fn load_cargo(
     with_proc_macro: bool,
 ) -> Result<(AnalysisHost, FxHashMap<SourceRootId, PackageRoot>)> {
     let root = std::env::current_dir()?.join(root);
-    let root = ProjectRoot::discover_single(&root)?;
+    let root = ProjectManifest::discover_single(&root)?;
     let ws = ProjectWorkspace::load(
         root,
         &CargoConfig { load_out_dirs_from_check, ..Default::default() },
@@ -36,28 +36,28 @@ pub fn load_cargo(
     )?;
 
     let mut extern_dirs = FxHashSet::default();
-    extern_dirs.extend(ws.out_dirs());
-
-    let mut project_roots = ws.to_roots();
-    project_roots.extend(extern_dirs.iter().cloned().map(PackageRoot::new_non_member));
 
     let (sender, receiver) = unbounded();
     let sender = Box::new(move |t| sender.send(t).unwrap());
-    let (mut vfs, roots) = Vfs::new(
-        project_roots
-            .iter()
-            .map(|pkg_root| {
-                RootEntry::new(
-                    pkg_root.path().to_owned(),
-                    RustPackageFilterBuilder::default()
-                        .set_member(pkg_root.is_member())
-                        .into_vfs_filter(),
-                )
-            })
-            .collect(),
-        sender,
-        Watch(false),
-    );
+
+    let mut roots = Vec::new();
+    let project_roots = ws.to_roots();
+    for root in &project_roots {
+        roots.push(RootEntry::new(
+            root.path().to_owned(),
+            RustPackageFilterBuilder::default().set_member(root.is_member()).into_vfs_filter(),
+        ));
+
+        if let Some(out_dir) = root.out_dir() {
+            extern_dirs.insert(out_dir.to_path_buf());
+            roots.push(RootEntry::new(
+                out_dir.to_owned(),
+                RustPackageFilterBuilder::default().set_member(root.is_member()).into_vfs_filter(),
+            ))
+        }
+    }
+
+    let (mut vfs, roots) = Vfs::new(roots, sender, Watch(false));
 
     let source_roots = roots
         .into_iter()
@@ -111,10 +111,6 @@ pub(crate) fn load(
                         vfs.root2path(root)
                     );
                     analysis_change.add_root(source_root_id, is_local);
-                    analysis_change.set_debug_root_path(
-                        source_root_id,
-                        source_roots[&source_root_id].path().display().to_string(),
-                    );
 
                     let vfs_root_path = vfs.root2path(root);
                     if extern_dirs.contains(&vfs_root_path) {
@@ -147,26 +143,14 @@ pub(crate) fn load(
         }
     }
 
-    // FIXME: cfg options?
-    let default_cfg_options = {
-        let mut opts = get_rustc_cfg_options(None);
-        opts.insert_atom("test".into());
-        opts.insert_atom("debug_assertion".into());
-        opts
-    };
-
-    let crate_graph = ws.to_crate_graph(
-        &default_cfg_options,
-        &extern_source_roots,
-        proc_macro_client,
-        &mut |path: &Path| {
+    let crate_graph =
+        ws.to_crate_graph(None, &extern_source_roots, proc_macro_client, &mut |path: &Path| {
             // Some path from metadata will be non canonicalized, e.g. /foo/../bar/lib.rs
             let path = path.canonicalize().ok()?;
             let vfs_file = vfs.load(&path);
             log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
             vfs_file.map(vfs_file_to_id)
-        },
-    );
+        });
     log::debug!("crate graph: {:?}", crate_graph);
     analysis_change.set_crate_graph(crate_graph);
 
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index c0f7c2c0c..1253db836 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -11,15 +11,14 @@ use std::{ffi::OsString, path::PathBuf};
 
 use lsp_types::ClientCapabilities;
 use ra_flycheck::FlycheckConfig;
-use ra_ide::{AssistConfig, CompletionConfig, InlayHintsConfig};
-use ra_project_model::CargoConfig;
+use ra_ide::{AssistConfig, CompletionConfig, HoverConfig, InlayHintsConfig};
+use ra_project_model::{CargoConfig, JsonProject, ProjectManifest};
 use serde::Deserialize;
 
 #[derive(Debug, Clone)]
 pub struct Config {
     pub client_caps: ClientCapsConfig,
 
-    pub with_sysroot: bool,
     pub publish_diagnostics: bool,
     pub lru_capacity: Option<usize>,
     pub proc_macro_srv: Option<(PathBuf, Vec<OsString>)>,
@@ -35,6 +34,28 @@ pub struct Config {
     pub assist: AssistConfig,
     pub call_info_full: bool,
     pub lens: LensConfig,
+    pub hover: HoverConfig,
+
+    pub with_sysroot: bool,
+    pub linked_projects: Vec<LinkedProject>,
+}
+
+#[derive(Debug, Clone)]
+pub enum LinkedProject {
+    ProjectManifest(ProjectManifest),
+    JsonProject(JsonProject),
+}
+
+impl From<ProjectManifest> for LinkedProject {
+    fn from(v: ProjectManifest) -> Self {
+        LinkedProject::ProjectManifest(v)
+    }
+}
+
+impl From<JsonProject> for LinkedProject {
+    fn from(v: JsonProject) -> Self {
+        LinkedProject::JsonProject(v)
+    }
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -103,6 +124,8 @@ pub struct ClientCapsConfig {
     pub code_action_literals: bool,
     pub work_done_progress: bool,
     pub code_action_group: bool,
+    pub resolve_code_action: bool,
+    pub hover_actions: bool,
 }
 
 impl Default for Config {
@@ -122,8 +145,9 @@ impl Default for Config {
             check: Some(FlycheckConfig::CargoCommand {
                 command: "check".to_string(),
                 all_targets: true,
-                all_features: true,
+                all_features: false,
                 extra_args: Vec::new(),
+                features: Vec::new(),
             }),
 
             inlay_hints: InlayHintsConfig {
@@ -141,6 +165,8 @@ impl Default for Config {
             assist: AssistConfig::default(),
             call_info_full: true,
             lens: LensConfig::default(),
+            hover: HoverConfig::default(),
+            linked_projects: Vec::new(),
         }
     }
 }
@@ -209,13 +235,14 @@ impl Config {
                 }
                 // otherwise configure command customizations
                 _ => {
-                    if let Some(FlycheckConfig::CargoCommand { command, extra_args, all_targets, all_features })
+                    if let Some(FlycheckConfig::CargoCommand { command, extra_args, all_targets, all_features, features })
                         = &mut self.check
                     {
                         set(value, "/checkOnSave/extraArgs", extra_args);
                         set(value, "/checkOnSave/command", command);
                         set(value, "/checkOnSave/allTargets", all_targets);
-                        set(value, "/checkOnSave/allFeatures", all_features);
+                        *all_features = get(value, "/checkOnSave/allFeatures").unwrap_or(self.cargo.all_features);
+                        *features = get(value, "/checkOnSave/features").unwrap_or(self.cargo.features.clone());
                     }
                 }
             };
@@ -240,6 +267,32 @@ impl Config {
             self.lens = LensConfig::NO_LENS;
         }
 
+        if let Some(linked_projects) = get::<Vec<ManifestOrJsonProject>>(value, "/linkedProjects") {
+            if !linked_projects.is_empty() {
+                self.linked_projects.clear();
+                for linked_project in linked_projects {
+                    let linked_project = match linked_project {
+                        ManifestOrJsonProject::Manifest(it) => match ProjectManifest::from_manifest_file(it) {
+                            Ok(it) => it.into(),
+                            Err(_) => continue,
+                        }
+                        ManifestOrJsonProject::JsonProject(it) => it.into(),
+                    };
+                    self.linked_projects.push(linked_project);
+                }
+            }
+        }
+
+        let mut use_hover_actions = false;
+        set(value, "/hoverActions/enable", &mut use_hover_actions);
+        if use_hover_actions {
+            set(value, "/hoverActions/implementations", &mut self.hover.implementations);
+            set(value, "/hoverActions/run", &mut self.hover.run);
+            set(value, "/hoverActions/debug", &mut self.hover.debug);
+        } else {
+            self.hover = HoverConfig::NO_ACTIONS;
+        }
+
         log::info!("Config::update() = {:#?}", self);
 
         fn get<'a, T: Deserialize<'a>>(value: &'a serde_json::Value, pointer: &str) -> Option<T> {
@@ -293,13 +346,22 @@ impl Config {
 
         self.assist.allow_snippets(false);
         if let Some(experimental) = &caps.experimental {
-            let snippet_text_edit =
-                experimental.get("snippetTextEdit").and_then(|it| it.as_bool()) == Some(true);
+            let get_bool =
+                |index: &str| experimental.get(index).and_then(|it| it.as_bool()) == Some(true);
+
+            let snippet_text_edit = get_bool("snippetTextEdit");
             self.assist.allow_snippets(snippet_text_edit);
 
-            let code_action_group =
-                experimental.get("codeActionGroup").and_then(|it| it.as_bool()) == Some(true);
-            self.client_caps.code_action_group = code_action_group
+            self.client_caps.code_action_group = get_bool("codeActionGroup");
+            self.client_caps.resolve_code_action = get_bool("resolveCodeAction");
+            self.client_caps.hover_actions = get_bool("hoverActions");
         }
     }
 }
+
+#[derive(Deserialize)]
+#[serde(untagged)]
+enum ManifestOrJsonProject {
+    Manifest(PathBuf),
+    JsonProject(JsonProject),
+}
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
index c40cfdcdc..272057b47 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
+++ b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_multi_line_fix.snap
@@ -65,6 +65,7 @@ expression: diag
         fixes: [
             CodeAction {
                 title: "return the expression directly",
+                id: None,
                 group: None,
                 kind: Some(
                     "quickfix",
diff --git a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
index 6dd3fcb2e..f0273315e 100644
--- a/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
+++ b/crates/rust-analyzer/src/diagnostics/snapshots/rust_analyzer__diagnostics__to_proto__tests__snap_rustc_unused_variable.snap
@@ -29,7 +29,7 @@ expression: diag
                 },
             },
             severity: Some(
-                Warning,
+                Hint,
             ),
             code: Some(
                 String(
@@ -50,6 +50,7 @@ expression: diag
         fixes: [
             CodeAction {
                 title: "consider prefixing with an underscore",
+                id: None,
                 group: None,
                 kind: Some(
                     "quickfix",
diff --git a/crates/rust-analyzer/src/diagnostics/to_proto.rs b/crates/rust-analyzer/src/diagnostics/to_proto.rs
index a500d670a..04e286780 100644
--- a/crates/rust-analyzer/src/diagnostics/to_proto.rs
+++ b/crates/rust-analyzer/src/diagnostics/to_proto.rs
@@ -145,6 +145,7 @@ fn map_rust_child_diagnostic(
     } else {
         MappedRustChildDiagnostic::SuggestedFix(lsp_ext::CodeAction {
             title: rd.message.clone(),
+            id: None,
             group: None,
             kind: Some("quickfix".to_string()),
             edit: Some(lsp_ext::SnippetWorkspaceEdit {
@@ -183,7 +184,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
         return Vec::new();
     }
 
-    let severity = map_level_to_severity(rd.level);
+    let mut severity = map_level_to_severity(rd.level);
 
     let mut source = String::from("rustc");
     let mut code = rd.code.as_ref().map(|c| c.code.clone());
@@ -225,6 +226,7 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
     }
 
     if is_unused_or_unnecessary(rd) {
+        severity = Some(DiagnosticSeverity::Hint);
         tags.push(DiagnosticTag::Unnecessary);
     }
 
diff --git a/crates/rust-analyzer/src/from_proto.rs b/crates/rust-analyzer/src/from_proto.rs
index 4bb16a496..206673829 100644
--- a/crates/rust-analyzer/src/from_proto.rs
+++ b/crates/rust-analyzer/src/from_proto.rs
@@ -3,7 +3,7 @@ use ra_db::{FileId, FilePosition, FileRange};
 use ra_ide::{LineCol, LineIndex};
 use ra_syntax::{TextRange, TextSize};
 
-use crate::{world::WorldSnapshot, Result};
+use crate::{global_state::GlobalStateSnapshot, Result};
 
 pub(crate) fn offset(line_index: &LineIndex, position: lsp_types::Position) -> TextSize {
     let line_col = LineCol { line: position.line as u32, col_utf16: position.character as u32 };
@@ -16,12 +16,12 @@ pub(crate) fn text_range(line_index: &LineIndex, range: lsp_types::Range) -> Tex
     TextRange::new(start, end)
 }
 
-pub(crate) fn file_id(world: &WorldSnapshot, url: &lsp_types::Url) -> Result<FileId> {
+pub(crate) fn file_id(world: &GlobalStateSnapshot, url: &lsp_types::Url) -> Result<FileId> {
     world.uri_to_file_id(url)
 }
 
 pub(crate) fn file_position(
-    world: &WorldSnapshot,
+    world: &GlobalStateSnapshot,
     tdpp: lsp_types::TextDocumentPositionParams,
 ) -> Result<FilePosition> {
     let file_id = file_id(world, &tdpp.text_document.uri)?;
@@ -31,7 +31,7 @@ pub(crate) fn file_position(
 }
 
 pub(crate) fn file_range(
-    world: &WorldSnapshot,
+    world: &GlobalStateSnapshot,
     text_document_identifier: lsp_types::TextDocumentIdentifier,
     range: lsp_types::Range,
 ) -> Result<FileRange> {
diff --git a/crates/rust-analyzer/src/world.rs b/crates/rust-analyzer/src/global_state.rs
index 367272925..21116e165 100644
--- a/crates/rust-analyzer/src/world.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -15,7 +15,7 @@ use ra_flycheck::{Flycheck, FlycheckConfig};
 use ra_ide::{
     Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, LibraryData, SourceRootId,
 };
-use ra_project_model::{get_rustc_cfg_options, ProcMacroClient, ProjectWorkspace};
+use ra_project_model::{ProcMacroClient, ProjectWorkspace};
 use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
 use relative_path::RelativePathBuf;
 use stdx::format_to;
@@ -50,15 +50,15 @@ fn create_flycheck(workspaces: &[ProjectWorkspace], config: &FlycheckConfig) ->
         })
 }
 
-/// `WorldState` is the primary mutable state of the language server
+/// `GlobalState` is the primary mutable state of the language server
 ///
 /// The most interesting components are `vfs`, which stores a consistent
 /// snapshot of the file systems, and `analysis_host`, which stores our
 /// incremental salsa database.
 #[derive(Debug)]
-pub struct WorldState {
+pub struct GlobalState {
     pub config: Config,
-    pub roots: Vec<PathBuf>,
+    pub local_roots: Vec<PathBuf>,
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis_host: AnalysisHost,
     pub vfs: Arc<RwLock<Vfs>>,
@@ -70,7 +70,7 @@ pub struct WorldState {
 }
 
 /// An immutable snapshot of the world's state at a point in time.
-pub struct WorldSnapshot {
+pub struct GlobalStateSnapshot {
     pub config: Config,
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis: Analysis,
@@ -79,20 +79,19 @@ pub struct WorldSnapshot {
     vfs: Arc<RwLock<Vfs>>,
 }
 
-impl WorldState {
+impl GlobalState {
     pub fn new(
-        folder_roots: Vec<PathBuf>,
         workspaces: Vec<ProjectWorkspace>,
         lru_capacity: Option<usize>,
         exclude_globs: &[Glob],
         watch: Watch,
         config: Config,
-    ) -> WorldState {
+    ) -> GlobalState {
         let mut change = AnalysisChange::new();
 
-        let extern_dirs: FxHashSet<_> =
-            workspaces.iter().flat_map(ProjectWorkspace::out_dirs).collect();
+        let mut extern_dirs: FxHashSet<PathBuf> = FxHashSet::default();
 
+        let mut local_roots = Vec::new();
         let roots: Vec<_> = {
             let create_filter = |is_member| {
                 RustPackageFilterBuilder::default()
@@ -100,18 +99,22 @@ impl WorldState {
                     .exclude(exclude_globs.iter().cloned())
                     .into_vfs_filter()
             };
-            folder_roots
-                .iter()
-                .map(|path| RootEntry::new(path.clone(), create_filter(true)))
-                .chain(workspaces.iter().flat_map(ProjectWorkspace::to_roots).map(|pkg_root| {
-                    RootEntry::new(pkg_root.path().to_owned(), create_filter(pkg_root.is_member()))
-                }))
-                .chain(
-                    extern_dirs
-                        .iter()
-                        .map(|path| RootEntry::new(path.to_owned(), create_filter(false))),
-                )
-                .collect()
+            let mut roots = Vec::new();
+            for root in workspaces.iter().flat_map(ProjectWorkspace::to_roots) {
+                let path = root.path().to_owned();
+                if root.is_member() {
+                    local_roots.push(path.clone());
+                }
+                roots.push(RootEntry::new(path, create_filter(root.is_member())));
+                if let Some(out_dir) = root.out_dir() {
+                    extern_dirs.insert(out_dir.to_path_buf());
+                    roots.push(RootEntry::new(
+                        out_dir.to_path_buf(),
+                        create_filter(root.is_member()),
+                    ))
+                }
+            }
+            roots
         };
 
         let (task_sender, task_receiver) = unbounded();
@@ -121,9 +124,8 @@ impl WorldState {
         let mut extern_source_roots = FxHashMap::default();
         for r in vfs_roots {
             let vfs_root_path = vfs.root2path(r);
-            let is_local = folder_roots.iter().any(|it| vfs_root_path.starts_with(it));
+            let is_local = local_roots.iter().any(|it| vfs_root_path.starts_with(it));
             change.add_root(SourceRootId(r.0), is_local);
-            change.set_debug_root_path(SourceRootId(r.0), vfs_root_path.display().to_string());
 
             // FIXME: add path2root in vfs to simpily this logic
             if extern_dirs.contains(&vfs_root_path) {
@@ -131,14 +133,6 @@ impl WorldState {
             }
         }
 
-        // FIXME: Read default cfgs from config
-        let default_cfg_options = {
-            let mut opts = get_rustc_cfg_options(config.cargo.target.as_ref());
-            opts.insert_atom("test".into());
-            opts.insert_atom("debug_assertion".into());
-            opts
-        };
-
         let proc_macro_client = match &config.proc_macro_srv {
             None => ProcMacroClient::dummy(),
             Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
@@ -164,7 +158,7 @@ impl WorldState {
         };
         for ws in workspaces.iter() {
             crate_graph.extend(ws.to_crate_graph(
-                &default_cfg_options,
+                config.cargo.target.as_deref(),
                 &extern_source_roots,
                 &proc_macro_client,
                 &mut load,
@@ -176,9 +170,9 @@ impl WorldState {
 
         let mut analysis_host = AnalysisHost::new(lru_capacity);
         analysis_host.apply_change(change);
-        WorldState {
+        GlobalState {
             config,
-            roots: folder_roots,
+            local_roots,
             workspaces: Arc::new(workspaces),
             analysis_host,
             vfs: Arc::new(RwLock::new(vfs)),
@@ -216,7 +210,7 @@ impl WorldState {
             match c {
                 VfsChange::AddRoot { root, files } => {
                     let root_path = self.vfs.read().root2path(root);
-                    let is_local = self.roots.iter().any(|r| root_path.starts_with(r));
+                    let is_local = self.local_roots.iter().any(|r| root_path.starts_with(r));
                     if is_local {
                         *roots_scanned += 1;
                         for (file, path, text) in files {
@@ -251,8 +245,8 @@ impl WorldState {
         self.analysis_host.apply_change(change);
     }
 
-    pub fn snapshot(&self) -> WorldSnapshot {
-        WorldSnapshot {
+    pub fn snapshot(&self) -> GlobalStateSnapshot {
+        GlobalStateSnapshot {
             config: self.config.clone(),
             workspaces: Arc::clone(&self.workspaces),
             analysis: self.analysis_host.analysis(),
@@ -275,7 +269,7 @@ impl WorldState {
     }
 }
 
-impl WorldSnapshot {
+impl GlobalStateSnapshot {
     pub fn analysis(&self) -> &Analysis {
         &self.analysis
     }
diff --git a/crates/rust-analyzer/src/lib.rs b/crates/rust-analyzer/src/lib.rs
index 57d0e9218..609cb69d3 100644
--- a/crates/rust-analyzer/src/lib.rs
+++ b/crates/rust-analyzer/src/lib.rs
@@ -26,7 +26,7 @@ mod main_loop;
 mod markdown;
 pub mod lsp_ext;
 pub mod config;
-mod world;
+mod global_state;
 mod diagnostics;
 mod semantic_tokens;
 
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index acb1dacb6..1371f6cb4 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -4,7 +4,6 @@ use std::{collections::HashMap, path::PathBuf};
 
 use lsp_types::request::Request;
 use lsp_types::{Position, Range, TextDocumentIdentifier};
-use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 pub enum AnalyzerStatus {}
@@ -98,6 +97,22 @@ pub struct JoinLinesParams {
     pub ranges: Vec<Range>,
 }
 
+pub enum ResolveCodeActionRequest {}
+
+impl Request for ResolveCodeActionRequest {
+    type Params = ResolveCodeActionParams;
+    type Result = Option<SnippetWorkspaceEdit>;
+    const METHOD: &'static str = "experimental/resolveCodeAction";
+}
+
+/// Params for the ResolveCodeActionRequest
+#[derive(Debug, Eq, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ResolveCodeActionParams {
+    pub code_action_params: lsp_types::CodeActionParams,
+    pub id: String,
+}
+
 pub enum OnEnter {}
 
 impl Request for OnEnter {
@@ -111,7 +126,7 @@ pub enum Runnables {}
 impl Request for Runnables {
     type Params = RunnablesParams;
     type Result = Vec<Runnable>;
-    const METHOD: &'static str = "rust-analyzer/runnables";
+    const METHOD: &'static str = "experimental/runnables";
 }
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -124,13 +139,28 @@ pub struct RunnablesParams {
 #[derive(Deserialize, Serialize, Debug)]
 #[serde(rename_all = "camelCase")]
 pub struct Runnable {
-    pub range: Range,
     pub label: String,
-    pub bin: String,
-    pub args: Vec<String>,
-    pub extra_args: Vec<String>,
-    pub env: FxHashMap<String, String>,
-    pub cwd: Option<PathBuf>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub location: Option<lsp_types::LocationLink>,
+    pub kind: RunnableKind,
+    pub args: CargoRunnable,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(rename_all = "lowercase")]
+pub enum RunnableKind {
+    Cargo,
+}
+
+#[derive(Deserialize, Serialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct CargoRunnable {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub workspace_root: Option<PathBuf>,
+    // command, --package and --lib stuff
+    pub cargo_args: Vec<String>,
+    // stuff after --
+    pub executable_args: Vec<String>,
 }
 
 pub enum InlayHints {}
@@ -188,6 +218,8 @@ impl Request for CodeActionRequest {
 pub struct CodeAction {
     pub title: String,
     #[serde(skip_serializing_if = "Option::is_none")]
+    pub id: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub group: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub kind: Option<String>,
@@ -228,3 +260,35 @@ pub struct SnippetTextEdit {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub insert_text_format: Option<lsp_types::InsertTextFormat>,
 }
+
+pub enum HoverRequest {}
+
+impl Request for HoverRequest {
+    type Params = lsp_types::HoverParams;
+    type Result = Option<Hover>;
+    const METHOD: &'static str = "textDocument/hover";
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+pub struct Hover {
+    #[serde(flatten)]
+    pub hover: lsp_types::Hover,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub actions: Vec<CommandLinkGroup>,
+}
+
+#[derive(Debug, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct CommandLinkGroup {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub title: Option<String>,
+    pub commands: Vec<CommandLink>,
+}
+
+// LSP v3.15 Command does not have a `tooltip` field, vscode supports one.
+#[derive(Debug, PartialEq, Clone, Default, Deserialize, Serialize)]
+pub struct CommandLink {
+    #[serde(flatten)]
+    pub command: lsp_types::Command,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tooltip: Option<String>,
+}
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index f1287d52c..752dbf145 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -12,13 +12,11 @@ use std::{
     fmt,
     ops::Range,
     panic,
-    path::PathBuf,
     sync::Arc,
     time::{Duration, Instant},
 };
 
 use crossbeam_channel::{never, select, unbounded, RecvError, Sender};
-use itertools::Itertools;
 use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
 use lsp_types::{
     DidChangeTextDocumentParams, NumberOrString, TextDocumentContentChangeEvent, WorkDoneProgress,
@@ -36,14 +34,15 @@ use serde::{de::DeserializeOwned, Serialize};
 use threadpool::ThreadPool;
 
 use crate::{
-    config::{Config, FilesWatcher},
+    config::{Config, FilesWatcher, LinkedProject},
     diagnostics::{to_proto::url_from_path_with_drive_lowercasing, DiagnosticTask},
-    from_proto, lsp_ext,
+    from_proto,
+    global_state::{GlobalState, GlobalStateSnapshot},
+    lsp_ext,
     main_loop::{
         pending_requests::{PendingRequest, PendingRequests},
         subscriptions::Subscriptions,
     },
-    world::{WorldSnapshot, WorldState},
     Result,
 };
 
@@ -69,7 +68,7 @@ impl fmt::Display for LspError {
 
 impl Error for LspError {}
 
-pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection) -> Result<()> {
+pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
     log::info!("initial config: {:#?}", config);
 
     // Windows scheduler implements priority boosts: if thread waits for an
@@ -92,43 +91,37 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
     }
 
     let mut loop_state = LoopState::default();
-    let mut world_state = {
+    let mut global_state = {
         let workspaces = {
-            // FIXME: support dynamic workspace loading.
-            let project_roots: FxHashSet<_> = ws_roots
-                .iter()
-                .filter_map(|it| ra_project_model::ProjectRoot::discover(it).ok())
-                .flatten()
-                .collect();
-
-            if project_roots.is_empty() && config.notifications.cargo_toml_not_found {
+            if config.linked_projects.is_empty() && config.notifications.cargo_toml_not_found {
                 show_message(
                     lsp_types::MessageType::Error,
-                    format!(
-                        "rust-analyzer failed to discover workspace, no Cargo.toml found, dirs searched: {}",
-                        ws_roots.iter().format_with(", ", |it, f| f(&it.display()))
-                    ),
+                    "rust-analyzer failed to discover workspace".to_string(),
                     &connection.sender,
                 );
             };
 
-            project_roots
-                .into_iter()
-                .filter_map(|root| {
-                    ra_project_model::ProjectWorkspace::load(
-                        root,
-                        &config.cargo,
-                        config.with_sysroot,
-                    )
-                    .map_err(|err| {
-                        log::error!("failed to load workspace: {:#}", err);
-                        show_message(
-                            lsp_types::MessageType::Error,
-                            format!("rust-analyzer failed to load workspace: {:#}", err),
-                            &connection.sender,
-                        );
-                    })
-                    .ok()
+            config
+                .linked_projects
+                .iter()
+                .filter_map(|project| match project {
+                    LinkedProject::ProjectManifest(manifest) => {
+                        ra_project_model::ProjectWorkspace::load(
+                            manifest.clone(),
+                            &config.cargo,
+                            config.with_sysroot,
+                        )
+                        .map_err(|err| {
+                            log::error!("failed to load workspace: {:#}", err);
+                            show_message(
+                                lsp_types::MessageType::Error,
+                                format!("rust-analyzer failed to load workspace: {:#}", err),
+                                &connection.sender,
+                            );
+                        })
+                        .ok()
+                    }
+                    LinkedProject::JsonProject(it) => Some(it.clone().into()),
                 })
                 .collect::<Vec<_>>()
         };
@@ -163,8 +156,7 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
             connection.sender.send(request.into()).unwrap();
         }
 
-        WorldState::new(
-            ws_roots,
+        GlobalState::new(
             workspaces,
             config.lru_capacity,
             &globs,
@@ -173,7 +165,7 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
         )
     };
 
-    loop_state.roots_total = world_state.vfs.read().n_roots();
+    loop_state.roots_total = global_state.vfs.read().n_roots();
 
     let pool = ThreadPool::default();
     let (task_sender, task_receiver) = unbounded::<Task>();
@@ -191,12 +183,12 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
                     Err(RecvError) => return Err("client exited without shutdown".into()),
                 },
                 recv(task_receiver) -> task => Event::Task(task.unwrap()),
-                recv(world_state.task_receiver) -> task => match task {
+                recv(global_state.task_receiver) -> task => match task {
                     Ok(task) => Event::Vfs(task),
                     Err(RecvError) => return Err("vfs died".into()),
                 },
                 recv(libdata_receiver) -> data => Event::Lib(data.unwrap()),
-                recv(world_state.flycheck.as_ref().map_or(&never(), |it| &it.task_recv)) -> task => match task {
+                recv(global_state.flycheck.as_ref().map_or(&never(), |it| &it.task_recv)) -> task => match task {
                     Ok(task) => Event::CheckWatcher(task),
                     Err(RecvError) => return Err("check watcher died".into()),
                 }
@@ -211,16 +203,16 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
                 &task_sender,
                 &libdata_sender,
                 &connection,
-                &mut world_state,
+                &mut global_state,
                 &mut loop_state,
                 event,
             )?;
         }
     }
-    world_state.analysis_host.request_cancellation();
+    global_state.analysis_host.request_cancellation();
     log::info!("waiting for tasks to finish...");
     task_receiver.into_iter().for_each(|task| {
-        on_task(task, &connection.sender, &mut loop_state.pending_requests, &mut world_state)
+        on_task(task, &connection.sender, &mut loop_state.pending_requests, &mut global_state)
     });
     libdata_receiver.into_iter().for_each(drop);
     log::info!("...tasks have finished");
@@ -229,7 +221,7 @@ pub fn main_loop(ws_roots: Vec<PathBuf>, config: Config, connection: Connection)
     drop(pool);
     log::info!("...threadpool has finished");
 
-    let vfs = Arc::try_unwrap(world_state.vfs).expect("all snapshots should be dead");
+    let vfs = Arc::try_unwrap(global_state.vfs).expect("all snapshots should be dead");
     drop(vfs);
 
     Ok(())
@@ -320,7 +312,7 @@ fn loop_turn(
     task_sender: &Sender<Task>,
     libdata_sender: &Sender<LibraryData>,
     connection: &Connection,
-    world_state: &mut WorldState,
+    global_state: &mut GlobalState,
     loop_state: &mut LoopState,
     event: Event,
 ) -> Result<()> {
@@ -336,22 +328,22 @@ fn loop_turn(
 
     match event {
         Event::Task(task) => {
-            on_task(task, &connection.sender, &mut loop_state.pending_requests, world_state);
-            world_state.maybe_collect_garbage();
+            on_task(task, &connection.sender, &mut loop_state.pending_requests, global_state);
+            global_state.maybe_collect_garbage();
         }
         Event::Vfs(task) => {
-            world_state.vfs.write().handle_task(task);
+            global_state.vfs.write().handle_task(task);
         }
         Event::Lib(lib) => {
-            world_state.add_lib(lib);
-            world_state.maybe_collect_garbage();
+            global_state.add_lib(lib);
+            global_state.maybe_collect_garbage();
             loop_state.in_flight_libraries -= 1;
             loop_state.roots_scanned += 1;
         }
-        Event::CheckWatcher(task) => on_check_task(task, world_state, task_sender)?,
+        Event::CheckWatcher(task) => on_check_task(task, global_state, task_sender)?,
         Event::Msg(msg) => match msg {
             Message::Request(req) => on_request(
-                world_state,
+                global_state,
                 &mut loop_state.pending_requests,
                 pool,
                 task_sender,
@@ -360,7 +352,7 @@ fn loop_turn(
                 req,
             )?,
             Message::Notification(not) => {
-                on_notification(&connection.sender, world_state, loop_state, not)?;
+                on_notification(&connection.sender, global_state, loop_state, not)?;
             }
             Message::Response(resp) => {
                 let removed = loop_state.pending_responses.remove(&resp.id);
@@ -379,9 +371,9 @@ fn loop_turn(
                         }
                         (None, Some(configs)) => {
                             if let Some(new_config) = configs.get(0) {
-                                let mut config = world_state.config.clone();
+                                let mut config = global_state.config.clone();
                                 config.update(&new_config);
-                                world_state.update_configuration(config);
+                                global_state.update_configuration(config);
                             }
                         }
                         (None, None) => {
@@ -394,7 +386,7 @@ fn loop_turn(
     };
 
     let mut state_changed = false;
-    if let Some(changes) = world_state.process_changes(&mut loop_state.roots_scanned) {
+    if let Some(changes) = global_state.process_changes(&mut loop_state.roots_scanned) {
         state_changed = true;
         loop_state.pending_libraries.extend(changes);
     }
@@ -416,7 +408,7 @@ fn loop_turn(
     }
 
     let show_progress =
-        !loop_state.workspace_loaded && world_state.config.client_caps.work_done_progress;
+        !loop_state.workspace_loaded && global_state.config.client_caps.work_done_progress;
 
     if !loop_state.workspace_loaded
         && loop_state.roots_scanned == loop_state.roots_total
@@ -425,7 +417,7 @@ fn loop_turn(
     {
         state_changed = true;
         loop_state.workspace_loaded = true;
-        if let Some(flycheck) = &world_state.flycheck {
+        if let Some(flycheck) = &global_state.flycheck {
             flycheck.update();
         }
     }
@@ -437,13 +429,13 @@ fn loop_turn(
     if state_changed && loop_state.workspace_loaded {
         update_file_notifications_on_threadpool(
             pool,
-            world_state.snapshot(),
+            global_state.snapshot(),
             task_sender.clone(),
             loop_state.subscriptions.subscriptions(),
         );
         pool.execute({
             let subs = loop_state.subscriptions.subscriptions();
-            let snap = world_state.snapshot();
+            let snap = global_state.snapshot();
             move || snap.analysis().prime_caches(subs).unwrap_or_else(|_: Canceled| ())
         });
     }
@@ -467,7 +459,7 @@ fn on_task(
     task: Task,
     msg_sender: &Sender<Message>,
     pending_requests: &mut PendingRequests,
-    state: &mut WorldState,
+    state: &mut GlobalState,
 ) {
     match task {
         Task::Respond(response) => {
@@ -485,7 +477,7 @@ fn on_task(
 }
 
 fn on_request(
-    world: &mut WorldState,
+    global_state: &mut GlobalState,
     pending_requests: &mut PendingRequests,
     pool: &ThreadPool,
     task_sender: &Sender<Task>,
@@ -496,7 +488,7 @@ fn on_request(
     let mut pool_dispatcher = PoolDispatcher {
         req: Some(req),
         pool,
-        world,
+        global_state,
         task_sender,
         msg_sender,
         pending_requests,
@@ -517,6 +509,8 @@ fn on_request(
         .on::<lsp_ext::Runnables>(handlers::handle_runnables)?
         .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)?
         .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)?
+        .on::<lsp_ext::ResolveCodeActionRequest>(handlers::handle_resolve_code_action)?
+        .on::<lsp_ext::HoverRequest>(handlers::handle_hover)?
         .on::<lsp_types::request::OnTypeFormatting>(handlers::handle_on_type_formatting)?
         .on::<lsp_types::request::DocumentSymbolRequest>(handlers::handle_document_symbol)?
         .on::<lsp_types::request::WorkspaceSymbol>(handlers::handle_workspace_symbol)?
@@ -528,7 +522,6 @@ fn on_request(
         .on::<lsp_types::request::CodeLensResolve>(handlers::handle_code_lens_resolve)?
         .on::<lsp_types::request::FoldingRangeRequest>(handlers::handle_folding_range)?
         .on::<lsp_types::request::SignatureHelpRequest>(handlers::handle_signature_help)?
-        .on::<lsp_types::request::HoverRequest>(handlers::handle_hover)?
         .on::<lsp_types::request::PrepareRenameRequest>(handlers::handle_prepare_rename)?
         .on::<lsp_types::request::Rename>(handlers::handle_rename)?
         .on::<lsp_types::request::References>(handlers::handle_references)?
@@ -552,7 +545,7 @@ fn on_request(
 
 fn on_notification(
     msg_sender: &Sender<Message>,
-    state: &mut WorldState,
+    state: &mut GlobalState,
     loop_state: &mut LoopState,
     not: Notification,
 ) -> Result<()> {
@@ -726,7 +719,7 @@ fn apply_document_changes(
 
 fn on_check_task(
     task: CheckTask,
-    world_state: &mut WorldState,
+    global_state: &mut GlobalState,
     task_sender: &Sender<Task>,
 ) -> Result<()> {
     match task {
@@ -745,7 +738,7 @@ fn on_check_task(
                     .uri
                     .to_file_path()
                     .map_err(|()| format!("invalid uri: {}", diag.location.uri))?;
-                let file_id = match world_state.vfs.read().path2file(&path) {
+                let file_id = match global_state.vfs.read().path2file(&path) {
                     Some(file) => FileId(file.0),
                     None => {
                         log::error!(
@@ -765,7 +758,7 @@ fn on_check_task(
         }
 
         CheckTask::Status(status) => {
-            if world_state.config.client_caps.work_done_progress {
+            if global_state.config.client_caps.work_done_progress {
                 let progress = match status {
                     Status::Being => {
                         lsp_types::WorkDoneProgress::Begin(lsp_types::WorkDoneProgressBegin {
@@ -804,7 +797,7 @@ fn on_check_task(
     Ok(())
 }
 
-fn on_diagnostic_task(task: DiagnosticTask, msg_sender: &Sender<Message>, state: &mut WorldState) {
+fn on_diagnostic_task(task: DiagnosticTask, msg_sender: &Sender<Message>, state: &mut GlobalState) {
     let subscriptions = state.diagnostics.handle_task(task);
 
     for file_id in subscriptions {
@@ -879,7 +872,7 @@ fn send_startup_progress(sender: &Sender<Message>, loop_state: &mut LoopState) {
 struct PoolDispatcher<'a> {
     req: Option<Request>,
     pool: &'a ThreadPool,
-    world: &'a mut WorldState,
+    global_state: &'a mut GlobalState,
     pending_requests: &'a mut PendingRequests,
     msg_sender: &'a Sender<Message>,
     task_sender: &'a Sender<Task>,
@@ -890,7 +883,7 @@ impl<'a> PoolDispatcher<'a> {
     /// Dispatches the request onto the current thread
     fn on_sync<R>(
         &mut self,
-        f: fn(&mut WorldState, R::Params) -> Result<R::Result>,
+        f: fn(&mut GlobalState, R::Params) -> Result<R::Result>,
     ) -> Result<&mut Self>
     where
         R: lsp_types::request::Request + 'static,
@@ -903,18 +896,21 @@ impl<'a> PoolDispatcher<'a> {
                 return Ok(self);
             }
         };
-        let world = panic::AssertUnwindSafe(&mut *self.world);
+        let world = panic::AssertUnwindSafe(&mut *self.global_state);
         let task = panic::catch_unwind(move || {
             let result = f(world.0, params);
             result_to_task::<R>(id, result)
         })
         .map_err(|_| format!("sync task {:?} panicked", R::METHOD))?;
-        on_task(task, self.msg_sender, self.pending_requests, self.world);
+        on_task(task, self.msg_sender, self.pending_requests, self.global_state);
         Ok(self)
     }
 
     /// Dispatches the request onto thread pool
-    fn on<R>(&mut self, f: fn(WorldSnapshot, R::Params) -> Result<R::Result>) -> Result<&mut Self>
+    fn on<R>(
+        &mut self,
+        f: fn(GlobalStateSnapshot, R::Params) -> Result<R::Result>,
+    ) -> Result<&mut Self>
     where
         R: lsp_types::request::Request + 'static,
         R::Params: DeserializeOwned + Send + 'static,
@@ -928,7 +924,7 @@ impl<'a> PoolDispatcher<'a> {
         };
 
         self.pool.execute({
-            let world = self.world.snapshot();
+            let world = self.global_state.snapshot();
             let sender = self.task_sender.clone();
             move || {
                 let result = f(world, params);
@@ -1012,7 +1008,7 @@ where
 
 fn update_file_notifications_on_threadpool(
     pool: &ThreadPool,
-    world: WorldSnapshot,
+    world: GlobalStateSnapshot,
     task_sender: Sender<Task>,
     subscriptions: Vec<FileId>,
 ) {
diff --git a/crates/rust-analyzer/src/main_loop/handlers.rs b/crates/rust-analyzer/src/main_loop/handlers.rs
index 1f910ff82..a41adf8b0 100644
--- a/crates/rust-analyzer/src/main_loop/handlers.rs
+++ b/crates/rust-analyzer/src/main_loop/handlers.rs
@@ -12,40 +12,37 @@ use lsp_types::{
     CallHierarchyIncomingCall, CallHierarchyIncomingCallsParams, CallHierarchyItem,
     CallHierarchyOutgoingCall, CallHierarchyOutgoingCallsParams, CallHierarchyPrepareParams,
     CodeLens, Command, CompletionItem, Diagnostic, DocumentFormattingParams, DocumentHighlight,
-    DocumentSymbol, FoldingRange, FoldingRangeParams, Hover, HoverContents, Location,
-    MarkupContent, MarkupKind, Position, PrepareRenameResponse, Range, RenameParams,
-    SemanticTokensParams, SemanticTokensRangeParams, SemanticTokensRangeResult,
-    SemanticTokensResult, SymbolInformation, TextDocumentIdentifier, Url, WorkspaceEdit,
+    DocumentSymbol, FoldingRange, FoldingRangeParams, HoverContents, Location, MarkupContent,
+    MarkupKind, Position, PrepareRenameResponse, Range, RenameParams, SemanticTokensParams,
+    SemanticTokensRangeParams, SemanticTokensRangeResult, SemanticTokensResult, SymbolInformation,
+    TextDocumentIdentifier, Url, WorkspaceEdit,
 };
-use ra_cfg::CfgExpr;
 use ra_ide::{
-    FileId, FilePosition, FileRange, Query, RangeInfo, Runnable, RunnableKind, SearchScope,
-    TextEdit,
+    FileId, FilePosition, FileRange, HoverAction, Query, RangeInfo, Runnable, RunnableKind,
+    SearchScope, TextEdit,
 };
 use ra_prof::profile;
 use ra_project_model::TargetKind;
-use ra_syntax::{AstNode, SmolStr, SyntaxKind, TextRange, TextSize};
-use rustc_hash::FxHashMap;
+use ra_syntax::{AstNode, SyntaxKind, TextRange, TextSize};
 use serde::{Deserialize, Serialize};
 use serde_json::to_value;
-use stdx::format_to;
+use stdx::{format_to, split1};
 
 use crate::{
     cargo_target_spec::CargoTargetSpec,
     config::RustfmtConfig,
     diagnostics::DiagnosticTask,
     from_json, from_proto,
+    global_state::GlobalStateSnapshot,
     lsp_ext::{self, InlayHint, InlayHintsParams},
-    to_proto,
-    world::WorldSnapshot,
-    LspError, Result,
+    to_proto, LspError, Result,
 };
 
-pub fn handle_analyzer_status(world: WorldSnapshot, _: ()) -> Result<String> {
+pub fn handle_analyzer_status(snap: GlobalStateSnapshot, _: ()) -> Result<String> {
     let _p = profile("handle_analyzer_status");
-    let mut buf = world.status();
+    let mut buf = snap.status();
     format_to!(buf, "\n\nrequests:\n");
-    let requests = world.latest_requests.read();
+    let requests = snap.latest_requests.read();
     for (is_last, r) in requests.iter() {
         let mark = if is_last { "*" } else { " " };
         format_to!(buf, "{}{:4} {:<36}{}ms\n", mark, r.id, r.method, r.duration.as_millis());
@@ -54,37 +51,37 @@ pub fn handle_analyzer_status(world: WorldSnapshot, _: ()) -> Result<String> {
 }
 
 pub fn handle_syntax_tree(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::SyntaxTreeParams,
 ) -> Result<String> {
     let _p = profile("handle_syntax_tree");
-    let id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(id)?;
+    let id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(id)?;
     let text_range = params.range.map(|r| from_proto::text_range(&line_index, r));
-    let res = world.analysis().syntax_tree(id, text_range)?;
+    let res = snap.analysis().syntax_tree(id, text_range)?;
     Ok(res)
 }
 
 pub fn handle_expand_macro(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::ExpandMacroParams,
 ) -> Result<Option<lsp_ext::ExpandedMacro>> {
     let _p = profile("handle_expand_macro");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
     let offset = from_proto::offset(&line_index, params.position);
 
-    let res = world.analysis().expand_macro(FilePosition { file_id, offset })?;
+    let res = snap.analysis().expand_macro(FilePosition { file_id, offset })?;
     Ok(res.map(|it| lsp_ext::ExpandedMacro { name: it.name, expansion: it.expansion }))
 }
 
 pub fn handle_selection_range(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::SelectionRangeParams,
 ) -> Result<Option<Vec<lsp_types::SelectionRange>>> {
     let _p = profile("handle_selection_range");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
     let res: Result<Vec<lsp_types::SelectionRange>> = params
         .positions
         .into_iter()
@@ -96,7 +93,7 @@ pub fn handle_selection_range(
                 loop {
                     ranges.push(range);
                     let frange = FileRange { file_id, range };
-                    let next = world.analysis().extend_selection(frange)?;
+                    let next = snap.analysis().extend_selection(frange)?;
                     if next == range {
                         break;
                     } else {
@@ -122,18 +119,18 @@ pub fn handle_selection_range(
 }
 
 pub fn handle_matching_brace(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::MatchingBraceParams,
 ) -> Result<Vec<Position>> {
     let _p = profile("handle_matching_brace");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
     let res = params
         .positions
         .into_iter()
         .map(|position| {
             let offset = from_proto::offset(&line_index, position);
-            let offset = match world.analysis().matching_brace(FilePosition { file_id, offset }) {
+            let offset = match snap.analysis().matching_brace(FilePosition { file_id, offset }) {
                 Ok(Some(matching_brace_offset)) => matching_brace_offset,
                 Err(_) | Ok(None) => offset,
             };
@@ -144,17 +141,17 @@ pub fn handle_matching_brace(
 }
 
 pub fn handle_join_lines(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::JoinLinesParams,
 ) -> Result<Vec<lsp_types::TextEdit>> {
     let _p = profile("handle_join_lines");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let line_endings = world.file_line_endings(file_id);
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let line_endings = snap.file_line_endings(file_id);
     let mut res = TextEdit::default();
     for range in params.ranges {
         let range = from_proto::text_range(&line_index, range);
-        let edit = world.analysis().join_lines(FileRange { file_id, range })?;
+        let edit = snap.analysis().join_lines(FileRange { file_id, range })?;
         match res.union(edit) {
             Ok(()) => (),
             Err(_edit) => {
@@ -167,37 +164,37 @@ pub fn handle_join_lines(
 }
 
 pub fn handle_on_enter(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<Vec<lsp_ext::SnippetTextEdit>>> {
     let _p = profile("handle_on_enter");
-    let position = from_proto::file_position(&world, params)?;
-    let edit = match world.analysis().on_enter(position)? {
+    let position = from_proto::file_position(&snap, params)?;
+    let edit = match snap.analysis().on_enter(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let line_index = snap.analysis().file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
     let edit = to_proto::snippet_text_edit_vec(&line_index, line_endings, true, edit);
     Ok(Some(edit))
 }
 
 // Don't forget to add new trigger characters to `ServerCapabilities` in `caps.rs`.
 pub fn handle_on_type_formatting(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentOnTypeFormattingParams,
 ) -> Result<Option<Vec<lsp_types::TextEdit>>> {
     let _p = profile("handle_on_type_formatting");
-    let mut position = from_proto::file_position(&world, params.text_document_position)?;
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let mut position = from_proto::file_position(&snap, params.text_document_position)?;
+    let line_index = snap.analysis().file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
 
     // in `ra_ide`, the `on_type` invariant is that
     // `text.char_at(position) == typed_char`.
     position.offset -= TextSize::of('.');
     let char_typed = params.ch.chars().next().unwrap_or('\0');
     assert!({
-        let text = world.analysis().file_text(position.file_id)?;
+        let text = snap.analysis().file_text(position.file_id)?;
         text[usize::from(position.offset)..].starts_with(char_typed)
     });
 
@@ -209,7 +206,7 @@ pub fn handle_on_type_formatting(
         return Ok(None);
     }
 
-    let edit = world.analysis().on_char_typed(position, char_typed)?;
+    let edit = snap.analysis().on_char_typed(position, char_typed)?;
     let mut edit = match edit {
         Some(it) => it,
         None => return Ok(None),
@@ -223,16 +220,16 @@ pub fn handle_on_type_formatting(
 }
 
 pub fn handle_document_symbol(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentSymbolParams,
 ) -> Result<Option<lsp_types::DocumentSymbolResponse>> {
     let _p = profile("handle_document_symbol");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
 
     let mut parents: Vec<(DocumentSymbol, Option<usize>)> = Vec::new();
 
-    for symbol in world.analysis().file_structure(file_id)? {
+    for symbol in snap.analysis().file_structure(file_id)? {
         let doc_symbol = DocumentSymbol {
             name: symbol.label,
             detail: symbol.detail,
@@ -258,10 +255,10 @@ pub fn handle_document_symbol(
         }
     }
 
-    let res = if world.config.client_caps.hierarchical_symbols {
+    let res = if snap.config.client_caps.hierarchical_symbols {
         document_symbols.into()
     } else {
-        let url = to_proto::url(&world, file_id)?;
+        let url = to_proto::url(&snap, file_id)?;
         let mut symbol_information = Vec::<SymbolInformation>::new();
         for symbol in document_symbols {
             flatten_document_symbol(&symbol, None, &url, &mut symbol_information);
@@ -291,7 +288,7 @@ pub fn handle_document_symbol(
 }
 
 pub fn handle_workspace_symbol(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::WorkspaceSymbolParams,
 ) -> Result<Option<Vec<SymbolInformation>>> {
     let _p = profile("handle_workspace_symbol");
@@ -309,22 +306,22 @@ pub fn handle_workspace_symbol(
         q.limit(128);
         q
     };
-    let mut res = exec_query(&world, query)?;
+    let mut res = exec_query(&snap, query)?;
     if res.is_empty() && !all_symbols {
         let mut query = Query::new(params.query);
         query.limit(128);
-        res = exec_query(&world, query)?;
+        res = exec_query(&snap, query)?;
     }
 
     return Ok(Some(res));
 
-    fn exec_query(world: &WorldSnapshot, query: Query) -> Result<Vec<SymbolInformation>> {
+    fn exec_query(snap: &GlobalStateSnapshot, query: Query) -> Result<Vec<SymbolInformation>> {
         let mut res = Vec::new();
-        for nav in world.analysis().symbol_search(query)? {
+        for nav in snap.analysis().symbol_search(query)? {
             let info = SymbolInformation {
                 name: nav.name().to_string(),
                 kind: to_proto::symbol_kind(nav.kind()),
-                location: to_proto::location(world, nav.file_range())?,
+                location: to_proto::location(snap, nav.file_range())?,
                 container_name: nav.container_name().map(|v| v.to_string()),
                 deprecated: None,
             };
@@ -335,88 +332,83 @@ pub fn handle_workspace_symbol(
 }
 
 pub fn handle_goto_definition(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::GotoDefinitionParams,
 ) -> Result<Option<lsp_types::GotoDefinitionResponse>> {
     let _p = profile("handle_goto_definition");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_definition(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis().goto_definition(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
 pub fn handle_goto_implementation(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::request::GotoImplementationParams,
 ) -> Result<Option<lsp_types::request::GotoImplementationResponse>> {
     let _p = profile("handle_goto_implementation");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_implementation(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis().goto_implementation(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
 pub fn handle_goto_type_definition(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::request::GotoTypeDefinitionParams,
 ) -> Result<Option<lsp_types::request::GotoTypeDefinitionResponse>> {
     let _p = profile("handle_goto_type_definition");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let nav_info = match world.analysis().goto_type_definition(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let nav_info = match snap.analysis().goto_type_definition(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
     let src = FileRange { file_id: position.file_id, range: nav_info.range };
-    let res = to_proto::goto_definition_response(&world, Some(src), nav_info.info)?;
+    let res = to_proto::goto_definition_response(&snap, Some(src), nav_info.info)?;
     Ok(Some(res))
 }
 
 pub fn handle_parent_module(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<lsp_types::GotoDefinitionResponse>> {
     let _p = profile("handle_parent_module");
-    let position = from_proto::file_position(&world, params)?;
-    let navs = world.analysis().parent_module(position)?;
-    let res = to_proto::goto_definition_response(&world, None, navs)?;
+    let position = from_proto::file_position(&snap, params)?;
+    let navs = snap.analysis().parent_module(position)?;
+    let res = to_proto::goto_definition_response(&snap, None, navs)?;
     Ok(Some(res))
 }
 
 pub fn handle_runnables(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::RunnablesParams,
 ) -> Result<Vec<lsp_ext::Runnable>> {
     let _p = profile("handle_runnables");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
     let offset = params.position.map(|it| from_proto::offset(&line_index, it));
     let mut res = Vec::new();
-    let workspace_root = world.workspace_root_for(file_id);
-    let cargo_spec = CargoTargetSpec::for_file(&world, file_id)?;
-    for runnable in world.analysis().runnables(file_id)? {
+    let workspace_root = snap.workspace_root_for(file_id);
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id)?;
+    for runnable in snap.analysis().runnables(file_id)? {
         if let Some(offset) = offset {
-            if !runnable.range.contains_inclusive(offset) {
+            if !runnable.nav.full_range().contains_inclusive(offset) {
                 continue;
             }
         }
-        // Do not suggest binary run on other target than binary
-        if let RunnableKind::Bin = runnable.kind {
-            if let Some(spec) = &cargo_spec {
-                match spec.target_kind {
-                    TargetKind::Bin => {}
-                    _ => continue,
-                }
-            }
+        if should_skip_target(&runnable, cargo_spec.as_ref()) {
+            continue;
         }
-        res.push(to_lsp_runnable(&world, file_id, runnable)?);
+
+        res.push(to_proto::runnable(&snap, file_id, runnable)?);
     }
 
     // Add `cargo check` and `cargo test` for the whole package
@@ -424,25 +416,31 @@ pub fn handle_runnables(
         Some(spec) => {
             for &cmd in ["check", "test"].iter() {
                 res.push(lsp_ext::Runnable {
-                    range: Default::default(),
                     label: format!("cargo {} -p {}", cmd, spec.package),
-                    bin: "cargo".to_string(),
-                    args: vec![cmd.to_string(), "--package".to_string(), spec.package.clone()],
-                    extra_args: Vec::new(),
-                    env: FxHashMap::default(),
-                    cwd: workspace_root.map(|root| root.to_owned()),
+                    location: None,
+                    kind: lsp_ext::RunnableKind::Cargo,
+                    args: lsp_ext::CargoRunnable {
+                        workspace_root: workspace_root.map(|root| root.to_owned()),
+                        cargo_args: vec![
+                            cmd.to_string(),
+                            "--package".to_string(),
+                            spec.package.clone(),
+                        ],
+                        executable_args: Vec::new(),
+                    },
                 })
             }
         }
         None => {
             res.push(lsp_ext::Runnable {
-                range: Default::default(),
                 label: "cargo check --workspace".to_string(),
-                bin: "cargo".to_string(),
-                args: vec!["check".to_string(), "--workspace".to_string()],
-                extra_args: Vec::new(),
-                env: FxHashMap::default(),
-                cwd: workspace_root.map(|root| root.to_owned()),
+                location: None,
+                kind: lsp_ext::RunnableKind::Cargo,
+                args: lsp_ext::CargoRunnable {
+                    workspace_root: workspace_root.map(|root| root.to_owned()),
+                    cargo_args: vec!["check".to_string(), "--workspace".to_string()],
+                    executable_args: Vec::new(),
+                },
             });
         }
     }
@@ -450,16 +448,16 @@ pub fn handle_runnables(
 }
 
 pub fn handle_completion(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::CompletionParams,
 ) -> Result<Option<lsp_types::CompletionResponse>> {
     let _p = profile("handle_completion");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
     let completion_triggered_after_single_colon = {
         let mut res = false;
         if let Some(ctx) = params.context {
             if ctx.trigger_character.unwrap_or_default() == ":" {
-                let source_file = world.analysis().parse(position.file_id)?;
+                let source_file = snap.analysis().parse(position.file_id)?;
                 let syntax = source_file.syntax();
                 let text = syntax.text();
                 if let Some(next_char) = text.char_at(position.offset) {
@@ -477,12 +475,12 @@ pub fn handle_completion(
         return Ok(None);
     }
 
-    let items = match world.analysis().completions(&world.config.completion, position)? {
+    let items = match snap.analysis().completions(&snap.config.completion, position)? {
         None => return Ok(None),
         Some(items) => items,
     };
-    let line_index = world.analysis().file_line_index(position.file_id)?;
-    let line_endings = world.file_line_endings(position.file_id);
+    let line_index = snap.analysis().file_line_index(position.file_id)?;
+    let line_endings = snap.file_line_endings(position.file_id);
     let items: Vec<CompletionItem> = items
         .into_iter()
         .map(|item| to_proto::completion_item(&line_index, line_endings, item))
@@ -492,15 +490,15 @@ pub fn handle_completion(
 }
 
 pub fn handle_folding_range(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: FoldingRangeParams,
 ) -> Result<Option<Vec<FoldingRange>>> {
     let _p = profile("handle_folding_range");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let folds = world.analysis().folding_ranges(file_id)?;
-    let text = world.analysis().file_text(file_id)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let line_folding_only = world.config.client_caps.line_folding_only;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let folds = snap.analysis().folding_ranges(file_id)?;
+    let text = snap.analysis().file_text(file_id)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let line_folding_only = snap.config.client_caps.line_folding_only;
     let res = folds
         .into_iter()
         .map(|it| to_proto::folding_range(&*text, &line_index, line_folding_only, it))
@@ -509,16 +507,16 @@ pub fn handle_folding_range(
 }
 
 pub fn handle_signature_help(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::SignatureHelpParams,
 ) -> Result<Option<lsp_types::SignatureHelp>> {
     let _p = profile("handle_signature_help");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let call_info = match world.analysis().call_info(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let call_info = match snap.analysis().call_info(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
-    let concise = !world.config.call_info_full;
+    let concise = !snap.config.call_info_full;
     let mut active_parameter = call_info.active_parameter.map(|it| it as i64);
     if concise && call_info.signature.has_self_param {
         active_parameter = active_parameter.map(|it| it.saturating_sub(1));
@@ -532,46 +530,56 @@ pub fn handle_signature_help(
     }))
 }
 
-pub fn handle_hover(world: WorldSnapshot, params: lsp_types::HoverParams) -> Result<Option<Hover>> {
+pub fn handle_hover(
+    snap: GlobalStateSnapshot,
+    params: lsp_types::HoverParams,
+) -> Result<Option<lsp_ext::Hover>> {
     let _p = profile("handle_hover");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let info = match world.analysis().hover(position)? {
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let info = match snap.analysis().hover(position)? {
         None => return Ok(None),
         Some(info) => info,
     };
-    let line_index = world.analysis.file_line_index(position.file_id)?;
+    let line_index = snap.analysis.file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, info.range);
-    let res = Hover {
-        contents: HoverContents::Markup(MarkupContent {
-            kind: MarkupKind::Markdown,
-            value: crate::markdown::format_docs(&info.info.to_markup()),
-        }),
-        range: Some(range),
+    let hover = lsp_ext::Hover {
+        hover: lsp_types::Hover {
+            contents: HoverContents::Markup(MarkupContent {
+                kind: MarkupKind::Markdown,
+                value: crate::markdown::format_docs(&info.info.to_markup()),
+            }),
+            range: Some(range),
+        },
+        actions: prepare_hover_actions(&snap, position.file_id, info.info.actions()),
     };
-    Ok(Some(res))
+
+    Ok(Some(hover))
 }
 
 pub fn handle_prepare_rename(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::TextDocumentPositionParams,
 ) -> Result<Option<PrepareRenameResponse>> {
     let _p = profile("handle_prepare_rename");
-    let position = from_proto::file_position(&world, params)?;
+    let position = from_proto::file_position(&snap, params)?;
 
-    let optional_change = world.analysis().rename(position, "dummy")?;
+    let optional_change = snap.analysis().rename(position, "dummy")?;
     let range = match optional_change {
         None => return Ok(None),
         Some(it) => it.range,
     };
 
-    let line_index = world.analysis().file_line_index(position.file_id)?;
+    let line_index = snap.analysis().file_line_index(position.file_id)?;
     let range = to_proto::range(&line_index, range);
     Ok(Some(PrepareRenameResponse::Range(range)))
 }
 
-pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Option<WorkspaceEdit>> {
+pub fn handle_rename(
+    snap: GlobalStateSnapshot,
+    params: RenameParams,
+) -> Result<Option<WorkspaceEdit>> {
     let _p = profile("handle_rename");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
 
     if params.new_name.is_empty() {
         return Err(LspError::new(
@@ -581,36 +589,36 @@ pub fn handle_rename(world: WorldSnapshot, params: RenameParams) -> Result<Optio
         .into());
     }
 
-    let optional_change = world.analysis().rename(position, &*params.new_name)?;
+    let optional_change = snap.analysis().rename(position, &*params.new_name)?;
     let source_change = match optional_change {
         None => return Ok(None),
         Some(it) => it.info,
     };
-    let workspace_edit = to_proto::workspace_edit(&world, source_change)?;
+    let workspace_edit = to_proto::workspace_edit(&snap, source_change)?;
     Ok(Some(workspace_edit))
 }
 
 pub fn handle_references(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::ReferenceParams,
 ) -> Result<Option<Vec<Location>>> {
     let _p = profile("handle_references");
-    let position = from_proto::file_position(&world, params.text_document_position)?;
+    let position = from_proto::file_position(&snap, params.text_document_position)?;
 
-    let refs = match world.analysis().find_all_refs(position, None)? {
+    let refs = match snap.analysis().find_all_refs(position, None)? {
         None => return Ok(None),
         Some(refs) => refs,
     };
 
     let locations = if params.context.include_declaration {
         refs.into_iter()
-            .filter_map(|reference| to_proto::location(&world, reference.file_range).ok())
+            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
             .collect()
     } else {
         // Only iterate over the references if include_declaration was false
         refs.references()
             .iter()
-            .filter_map(|reference| to_proto::location(&world, reference.file_range).ok())
+            .filter_map(|reference| to_proto::location(&snap, reference.file_range).ok())
             .collect()
     };
 
@@ -618,24 +626,24 @@ pub fn handle_references(
 }
 
 pub fn handle_formatting(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: DocumentFormattingParams,
 ) -> Result<Option<Vec<lsp_types::TextEdit>>> {
     let _p = profile("handle_formatting");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let file = world.analysis().file_text(file_id)?;
-    let crate_ids = world.analysis().crate_for(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let file = snap.analysis().file_text(file_id)?;
+    let crate_ids = snap.analysis().crate_for(file_id)?;
 
-    let file_line_index = world.analysis().file_line_index(file_id)?;
+    let file_line_index = snap.analysis().file_line_index(file_id)?;
     let end_position = to_proto::position(&file_line_index, TextSize::of(file.as_str()));
 
-    let mut rustfmt = match &world.config.rustfmt {
+    let mut rustfmt = match &snap.config.rustfmt {
         RustfmtConfig::Rustfmt { extra_args } => {
             let mut cmd = process::Command::new("rustfmt");
             cmd.args(extra_args);
             if let Some(&crate_id) = crate_ids.first() {
                 // Assume all crates are in the same edition
-                let edition = world.analysis().crate_edition(crate_id)?;
+                let edition = snap.analysis().crate_edition(crate_id)?;
                 cmd.arg("--edition");
                 cmd.arg(edition.to_string());
             }
@@ -693,136 +701,145 @@ pub fn handle_formatting(
     }]))
 }
 
-pub fn handle_code_action(
-    world: WorldSnapshot,
-    params: lsp_types::CodeActionParams,
-) -> Result<Option<Vec<lsp_ext::CodeAction>>> {
-    let _p = profile("handle_code_action");
-    // We intentionally don't support command-based actions, as those either
-    // requires custom client-code anyway, or requires server-initiated edits.
-    // Server initiated edits break causality, so we avoid those as well.
-    if !world.config.client_caps.code_action_literals {
-        return Ok(None);
-    }
-
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+fn handle_fixes(
+    snap: &GlobalStateSnapshot,
+    params: &lsp_types::CodeActionParams,
+    res: &mut Vec<lsp_ext::CodeAction>,
+) -> Result<()> {
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
     let range = from_proto::text_range(&line_index, params.range);
-    let frange = FileRange { file_id, range };
-
-    let diagnostics = world.analysis().diagnostics(file_id)?;
-    let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
+    let diagnostics = snap.analysis().diagnostics(file_id)?;
 
     let fixes_from_diagnostics = diagnostics
         .into_iter()
         .filter_map(|d| Some((d.range, d.fix?)))
         .filter(|(diag_range, _fix)| diag_range.intersect(range).is_some())
         .map(|(_range, fix)| fix);
-
     for fix in fixes_from_diagnostics {
         let title = fix.label;
-        let edit = to_proto::snippet_workspace_edit(&world, fix.source_change)?;
-        let action =
-            lsp_ext::CodeAction { title, group: None, kind: None, edit: Some(edit), command: None };
+        let edit = to_proto::snippet_workspace_edit(&snap, fix.source_change)?;
+        let action = lsp_ext::CodeAction {
+            title,
+            id: None,
+            group: None,
+            kind: Some(lsp_types::code_action_kind::QUICKFIX.into()),
+            edit: Some(edit),
+            command: None,
+        };
         res.push(action);
     }
 
-    for fix in world.check_fixes.get(&file_id).into_iter().flatten() {
+    for fix in snap.check_fixes.get(&file_id).into_iter().flatten() {
         let fix_range = from_proto::text_range(&line_index, fix.range);
         if fix_range.intersect(range).is_none() {
             continue;
         }
         res.push(fix.action.clone());
     }
+    Ok(())
+}
 
-    for assist in world.analysis().assists(&world.config.assist, frange)?.into_iter() {
-        res.push(to_proto::code_action(&world, assist)?.into());
+pub fn handle_code_action(
+    snap: GlobalStateSnapshot,
+    params: lsp_types::CodeActionParams,
+) -> Result<Option<Vec<lsp_ext::CodeAction>>> {
+    let _p = profile("handle_code_action");
+    // We intentionally don't support command-based actions, as those either
+    // requires custom client-code anyway, or requires server-initiated edits.
+    // Server initiated edits break causality, so we avoid those as well.
+    if !snap.config.client_caps.code_action_literals {
+        return Ok(None);
+    }
+
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let range = from_proto::text_range(&line_index, params.range);
+    let frange = FileRange { file_id, range };
+    let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
+
+    handle_fixes(&snap, &params, &mut res)?;
+
+    if snap.config.client_caps.resolve_code_action {
+        for (index, assist) in
+            snap.analysis().unresolved_assists(&snap.config.assist, frange)?.into_iter().enumerate()
+        {
+            res.push(to_proto::unresolved_code_action(&snap, assist, index)?);
+        }
+    } else {
+        for assist in snap.analysis().resolved_assists(&snap.config.assist, frange)?.into_iter() {
+            res.push(to_proto::resolved_code_action(&snap, assist)?);
+        }
     }
+
     Ok(Some(res))
 }
 
+pub fn handle_resolve_code_action(
+    snap: GlobalStateSnapshot,
+    params: lsp_ext::ResolveCodeActionParams,
+) -> Result<Option<lsp_ext::SnippetWorkspaceEdit>> {
+    let _p = profile("handle_resolve_code_action");
+    let file_id = from_proto::file_id(&snap, &params.code_action_params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let range = from_proto::text_range(&line_index, params.code_action_params.range);
+    let frange = FileRange { file_id, range };
+
+    let assists = snap.analysis().resolved_assists(&snap.config.assist, frange)?;
+    let (id_string, index) = split1(&params.id, ':').unwrap();
+    let index = index.parse::<usize>().unwrap();
+    let assist = &assists[index];
+    assert!(assist.assist.id.0 == id_string);
+    Ok(to_proto::resolved_code_action(&snap, assist.clone())?.edit)
+}
+
 pub fn handle_code_lens(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::CodeLensParams,
 ) -> Result<Option<Vec<CodeLens>>> {
     let _p = profile("handle_code_lens");
     let mut lenses: Vec<CodeLens> = Default::default();
 
-    if world.config.lens.none() {
+    if snap.config.lens.none() {
         // early return before any db query!
         return Ok(Some(lenses));
     }
 
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let cargo_spec = CargoTargetSpec::for_file(&world, file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id)?;
 
-    if world.config.lens.runnable() {
+    if snap.config.lens.runnable() {
         // Gather runnables
-        for runnable in world.analysis().runnables(file_id)? {
-            let (run_title, debugee) = match &runnable.kind {
-                RunnableKind::Test { .. } | RunnableKind::TestMod { .. } => {
-                    ("▶\u{fe0e} Run Test", true)
-                }
-                RunnableKind::DocTest { .. } => {
-                    // cargo does not support -no-run for doctests
-                    ("▶\u{fe0e} Run Doctest", false)
-                }
-                RunnableKind::Bench { .. } => {
-                    // Nothing wrong with bench debugging
-                    ("Run Bench", true)
-                }
-                RunnableKind::Bin => {
-                    // Do not suggest binary run on other target than binary
-                    match &cargo_spec {
-                        Some(spec) => match spec.target_kind {
-                            TargetKind::Bin => ("Run", true),
-                            _ => continue,
-                        },
-                        None => continue,
-                    }
-                }
-            };
+        for runnable in snap.analysis().runnables(file_id)? {
+            if should_skip_target(&runnable, cargo_spec.as_ref()) {
+                continue;
+            }
 
-            let mut r = to_lsp_runnable(&world, file_id, runnable)?;
-            if world.config.lens.run {
+            let action = runnable.action();
+            let range = to_proto::range(&line_index, runnable.nav.range());
+            let r = to_proto::runnable(&snap, file_id, runnable)?;
+            if snap.config.lens.run {
                 let lens = CodeLens {
-                    range: r.range,
-                    command: Some(Command {
-                        title: run_title.to_string(),
-                        command: "rust-analyzer.runSingle".into(),
-                        arguments: Some(vec![to_value(&r).unwrap()]),
-                    }),
+                    range,
+                    command: Some(run_single_command(&r, action.run_title)),
                     data: None,
                 };
                 lenses.push(lens);
             }
 
-            if debugee && world.config.lens.debug {
-                if r.args[0] == "run" {
-                    r.args[0] = "build".into();
-                } else {
-                    r.args.push("--no-run".into());
-                }
-                let debug_lens = CodeLens {
-                    range: r.range,
-                    command: Some(Command {
-                        title: "Debug".into(),
-                        command: "rust-analyzer.debugSingle".into(),
-                        arguments: Some(vec![to_value(r).unwrap()]),
-                    }),
-                    data: None,
-                };
+            if action.debugee && snap.config.lens.debug {
+                let debug_lens =
+                    CodeLens { range, command: Some(debug_single_command(&r)), data: None };
                 lenses.push(debug_lens);
             }
         }
     }
 
-    if world.config.lens.impementations {
+    if snap.config.lens.impementations {
         // Handle impls
         lenses.extend(
-            world
-                .analysis()
+            snap.analysis()
                 .file_structure(file_id)?
                 .into_iter()
                 .filter(|it| match it.kind {
@@ -857,14 +874,17 @@ enum CodeLensResolveData {
     Impls(lsp_types::request::GotoImplementationParams),
 }
 
-pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Result<CodeLens> {
+pub fn handle_code_lens_resolve(
+    snap: GlobalStateSnapshot,
+    code_lens: CodeLens,
+) -> Result<CodeLens> {
     let _p = profile("handle_code_lens_resolve");
     let data = code_lens.data.unwrap();
     let resolve = from_json::<Option<CodeLensResolveData>>("CodeLensResolveData", data)?;
     match resolve {
         Some(CodeLensResolveData::Impls(lens_params)) => {
             let locations: Vec<Location> =
-                match handle_goto_implementation(world, lens_params.clone())? {
+                match handle_goto_implementation(snap, lens_params.clone())? {
                     Some(lsp_types::GotoDefinitionResponse::Scalar(loc)) => vec![loc],
                     Some(lsp_types::GotoDefinitionResponse::Array(locs)) => locs,
                     Some(lsp_types::GotoDefinitionResponse::Link(links)) => links
@@ -874,24 +894,13 @@ pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Re
                     _ => vec![],
                 };
 
-            let title = if locations.len() == 1 {
-                "1 implementation".into()
-            } else {
-                format!("{} implementations", locations.len())
-            };
-
-            // We cannot use the 'editor.action.showReferences' command directly
-            // because that command requires vscode types which we convert in the handler
-            // on the client side.
-            let cmd = Command {
+            let title = implementation_title(locations.len());
+            let cmd = show_references_command(
                 title,
-                command: "rust-analyzer.showReferences".into(),
-                arguments: Some(vec![
-                    to_value(&lens_params.text_document_position_params.text_document.uri).unwrap(),
-                    to_value(code_lens.range.start).unwrap(),
-                    to_value(locations).unwrap(),
-                ]),
-            };
+                &lens_params.text_document_position_params.text_document.uri,
+                code_lens.range.start,
+                locations,
+            );
             Ok(CodeLens { range: code_lens.range, command: Some(cmd), data: None })
         }
         None => Ok(CodeLens {
@@ -903,14 +912,14 @@ pub fn handle_code_lens_resolve(world: WorldSnapshot, code_lens: CodeLens) -> Re
 }
 
 pub fn handle_document_highlight(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_types::DocumentHighlightParams,
 ) -> Result<Option<Vec<DocumentHighlight>>> {
     let _p = profile("handle_document_highlight");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
-    let line_index = world.analysis().file_line_index(position.file_id)?;
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
+    let line_index = snap.analysis().file_line_index(position.file_id)?;
 
-    let refs = match world
+    let refs = match snap
         .analysis()
         .find_all_refs(position, Some(SearchScope::single_file(position.file_id)))?
     {
@@ -930,19 +939,19 @@ pub fn handle_document_highlight(
 }
 
 pub fn handle_ssr(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: lsp_ext::SsrParams,
 ) -> Result<lsp_types::WorkspaceEdit> {
     let _p = profile("handle_ssr");
     let source_change =
-        world.analysis().structural_search_replace(&params.query, params.parse_only)??;
-    to_proto::workspace_edit(&world, source_change)
+        snap.analysis().structural_search_replace(&params.query, params.parse_only)??;
+    to_proto::workspace_edit(&snap, source_change)
 }
 
-pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<DiagnosticTask> {
+pub fn publish_diagnostics(snap: &GlobalStateSnapshot, file_id: FileId) -> Result<DiagnosticTask> {
     let _p = profile("publish_diagnostics");
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let diagnostics: Vec<Diagnostic> = world
+    let line_index = snap.analysis().file_line_index(file_id)?;
+    let diagnostics: Vec<Diagnostic> = snap
         .analysis()
         .diagnostics(file_id)?
         .into_iter()
@@ -959,87 +968,29 @@ pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<Dia
     Ok(DiagnosticTask::SetNative(file_id, diagnostics))
 }
 
-fn to_lsp_runnable(
-    world: &WorldSnapshot,
-    file_id: FileId,
-    runnable: Runnable,
-) -> Result<lsp_ext::Runnable> {
-    let spec = CargoTargetSpec::for_file(world, file_id)?;
-    let target = spec.as_ref().map(|s| s.target.clone());
-    let mut features_needed = vec![];
-    for cfg_expr in &runnable.cfg_exprs {
-        collect_minimal_features_needed(cfg_expr, &mut features_needed);
-    }
-    let (args, extra_args) =
-        CargoTargetSpec::runnable_args(spec, &runnable.kind, &features_needed)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
-    let label = match &runnable.kind {
-        RunnableKind::Test { test_id, .. } => format!("test {}", test_id),
-        RunnableKind::TestMod { path } => format!("test-mod {}", path),
-        RunnableKind::Bench { test_id } => format!("bench {}", test_id),
-        RunnableKind::DocTest { test_id, .. } => format!("doctest {}", test_id),
-        RunnableKind::Bin => {
-            target.map_or_else(|| "run binary".to_string(), |t| format!("run {}", t))
-        }
-    };
-    Ok(lsp_ext::Runnable {
-        range: to_proto::range(&line_index, runnable.range),
-        label,
-        bin: "cargo".to_string(),
-        args,
-        extra_args,
-        env: {
-            let mut m = FxHashMap::default();
-            m.insert("RUST_BACKTRACE".to_string(), "short".to_string());
-            m
-        },
-        cwd: world.workspace_root_for(file_id).map(|root| root.to_owned()),
-    })
-}
-
-/// Fill minimal features needed
-fn collect_minimal_features_needed(cfg_expr: &CfgExpr, features: &mut Vec<SmolStr>) {
-    match cfg_expr {
-        CfgExpr::KeyValue { key, value } if key == "feature" => features.push(value.clone()),
-        CfgExpr::All(preds) => {
-            preds.iter().for_each(|cfg| collect_minimal_features_needed(cfg, features));
-        }
-        CfgExpr::Any(preds) => {
-            for cfg in preds {
-                let len_features = features.len();
-                collect_minimal_features_needed(cfg, features);
-                if len_features != features.len() {
-                    break;
-                }
-            }
-        }
-        _ => {}
-    }
-}
-
 pub fn handle_inlay_hints(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: InlayHintsParams,
 ) -> Result<Vec<InlayHint>> {
     let _p = profile("handle_inlay_hints");
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let analysis = world.analysis();
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let analysis = snap.analysis();
     let line_index = analysis.file_line_index(file_id)?;
     Ok(analysis
-        .inlay_hints(file_id, &world.config.inlay_hints)?
+        .inlay_hints(file_id, &snap.config.inlay_hints)?
         .into_iter()
         .map(|it| to_proto::inlay_int(&line_index, it))
         .collect())
 }
 
 pub fn handle_call_hierarchy_prepare(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: CallHierarchyPrepareParams,
 ) -> Result<Option<Vec<CallHierarchyItem>>> {
     let _p = profile("handle_call_hierarchy_prepare");
-    let position = from_proto::file_position(&world, params.text_document_position_params)?;
+    let position = from_proto::file_position(&snap, params.text_document_position_params)?;
 
-    let nav_info = match world.analysis().call_hierarchy(position)? {
+    let nav_info = match snap.analysis().call_hierarchy(position)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1048,24 +999,24 @@ pub fn handle_call_hierarchy_prepare(
     let res = navs
         .into_iter()
         .filter(|it| it.kind() == SyntaxKind::FN_DEF)
-        .map(|it| to_proto::call_hierarchy_item(&world, it))
+        .map(|it| to_proto::call_hierarchy_item(&snap, it))
         .collect::<Result<Vec<_>>>()?;
 
     Ok(Some(res))
 }
 
 pub fn handle_call_hierarchy_incoming(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: CallHierarchyIncomingCallsParams,
 ) -> Result<Option<Vec<CallHierarchyIncomingCall>>> {
     let _p = profile("handle_call_hierarchy_incoming");
     let item = params.item;
 
     let doc = TextDocumentIdentifier::new(item.uri);
-    let frange = from_proto::file_range(&world, doc, item.range)?;
+    let frange = from_proto::file_range(&snap, doc, item.range)?;
     let fpos = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
 
-    let call_items = match world.analysis().incoming_calls(fpos)? {
+    let call_items = match snap.analysis().incoming_calls(fpos)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1074,8 +1025,8 @@ pub fn handle_call_hierarchy_incoming(
 
     for call_item in call_items.into_iter() {
         let file_id = call_item.target.file_id();
-        let line_index = world.analysis().file_line_index(file_id)?;
-        let item = to_proto::call_hierarchy_item(&world, call_item.target)?;
+        let line_index = snap.analysis().file_line_index(file_id)?;
+        let item = to_proto::call_hierarchy_item(&snap, call_item.target)?;
         res.push(CallHierarchyIncomingCall {
             from: item,
             from_ranges: call_item
@@ -1090,17 +1041,17 @@ pub fn handle_call_hierarchy_incoming(
 }
 
 pub fn handle_call_hierarchy_outgoing(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: CallHierarchyOutgoingCallsParams,
 ) -> Result<Option<Vec<CallHierarchyOutgoingCall>>> {
     let _p = profile("handle_call_hierarchy_outgoing");
     let item = params.item;
 
     let doc = TextDocumentIdentifier::new(item.uri);
-    let frange = from_proto::file_range(&world, doc, item.range)?;
+    let frange = from_proto::file_range(&snap, doc, item.range)?;
     let fpos = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
 
-    let call_items = match world.analysis().outgoing_calls(fpos)? {
+    let call_items = match snap.analysis().outgoing_calls(fpos)? {
         None => return Ok(None),
         Some(it) => it,
     };
@@ -1109,8 +1060,8 @@ pub fn handle_call_hierarchy_outgoing(
 
     for call_item in call_items.into_iter() {
         let file_id = call_item.target.file_id();
-        let line_index = world.analysis().file_line_index(file_id)?;
-        let item = to_proto::call_hierarchy_item(&world, call_item.target)?;
+        let line_index = snap.analysis().file_line_index(file_id)?;
+        let item = to_proto::call_hierarchy_item(&snap, call_item.target)?;
         res.push(CallHierarchyOutgoingCall {
             to: item,
             from_ranges: call_item
@@ -1125,82 +1076,165 @@ pub fn handle_call_hierarchy_outgoing(
 }
 
 pub fn handle_semantic_tokens(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: SemanticTokensParams,
 ) -> Result<Option<SemanticTokensResult>> {
     let _p = profile("handle_semantic_tokens");
 
-    let file_id = from_proto::file_id(&world, &params.text_document.uri)?;
-    let text = world.analysis().file_text(file_id)?;
-    let line_index = world.analysis().file_line_index(file_id)?;
+    let file_id = from_proto::file_id(&snap, &params.text_document.uri)?;
+    let text = snap.analysis().file_text(file_id)?;
+    let line_index = snap.analysis().file_line_index(file_id)?;
 
-    let highlights = world.analysis().highlight(file_id)?;
+    let highlights = snap.analysis().highlight(file_id)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
     Ok(Some(semantic_tokens.into()))
 }
 
 pub fn handle_semantic_tokens_range(
-    world: WorldSnapshot,
+    snap: GlobalStateSnapshot,
     params: SemanticTokensRangeParams,
 ) -> Result<Option<SemanticTokensRangeResult>> {
     let _p = profile("handle_semantic_tokens_range");
 
-    let frange = from_proto::file_range(&world, params.text_document, params.range)?;
-    let text = world.analysis().file_text(frange.file_id)?;
-    let line_index = world.analysis().file_line_index(frange.file_id)?;
+    let frange = from_proto::file_range(&snap, params.text_document, params.range)?;
+    let text = snap.analysis().file_text(frange.file_id)?;
+    let line_index = snap.analysis().file_line_index(frange.file_id)?;
 
-    let highlights = world.analysis().highlight_range(frange)?;
+    let highlights = snap.analysis().highlight_range(frange)?;
     let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
     Ok(Some(semantic_tokens.into()))
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+fn implementation_title(count: usize) -> String {
+    if count == 1 {
+        "1 implementation".into()
+    } else {
+        format!("{} implementations", count)
+    }
+}
 
-    use mbe::{ast_to_token_tree, TokenMap};
-    use ra_cfg::parse_cfg;
-    use ra_syntax::{
-        ast::{self, AstNode},
-        SmolStr,
-    };
+fn show_references_command(
+    title: String,
+    uri: &lsp_types::Url,
+    position: lsp_types::Position,
+    locations: Vec<lsp_types::Location>,
+) -> Command {
+    // We cannot use the 'editor.action.showReferences' command directly
+    // because that command requires vscode types which we convert in the handler
+    // on the client side.
+
+    Command {
+        title,
+        command: "rust-analyzer.showReferences".into(),
+        arguments: Some(vec![
+            to_value(uri).unwrap(),
+            to_value(position).unwrap(),
+            to_value(locations).unwrap(),
+        ]),
+    }
+}
 
-    fn get_token_tree_generated(input: &str) -> (tt::Subtree, TokenMap) {
-        let source_file = ast::SourceFile::parse(input).ok().unwrap();
-        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
-        ast_to_token_tree(&tt).unwrap()
+fn run_single_command(runnable: &lsp_ext::Runnable, title: &str) -> Command {
+    Command {
+        title: title.to_string(),
+        command: "rust-analyzer.runSingle".into(),
+        arguments: Some(vec![to_value(runnable).unwrap()]),
     }
+}
 
-    #[test]
-    fn test_cfg_expr_minimal_features_needed() {
-        let (subtree, _) = get_token_tree_generated(r#"#![cfg(feature = "baz")]"#);
-        let cfg_expr = parse_cfg(&subtree);
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
+fn debug_single_command(runnable: &lsp_ext::Runnable) -> Command {
+    Command {
+        title: "Debug".into(),
+        command: "rust-analyzer.debugSingle".into(),
+        arguments: Some(vec![to_value(runnable).unwrap()]),
+    }
+}
 
-        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+fn to_command_link(command: Command, tooltip: String) -> lsp_ext::CommandLink {
+    lsp_ext::CommandLink { tooltip: Some(tooltip), command }
+}
 
-        let (subtree, _) =
-            get_token_tree_generated(r#"#![cfg(all(feature = "baz", feature = "foo"))]"#);
-        let cfg_expr = parse_cfg(&subtree);
+fn show_impl_command_link(
+    snap: &GlobalStateSnapshot,
+    position: &FilePosition,
+) -> Option<lsp_ext::CommandLinkGroup> {
+    if snap.config.hover.implementations {
+        if let Some(nav_data) = snap.analysis().goto_implementation(*position).unwrap_or(None) {
+            let uri = to_proto::url(snap, position.file_id).ok()?;
+            let line_index = snap.analysis().file_line_index(position.file_id).ok()?;
+            let position = to_proto::position(&line_index, position.offset);
+            let locations: Vec<_> = nav_data
+                .info
+                .iter()
+                .filter_map(|it| to_proto::location(snap, it.file_range()).ok())
+                .collect();
+            let title = implementation_title(locations.len());
+            let command = show_references_command(title, &uri, position, locations);
+
+            return Some(lsp_ext::CommandLinkGroup {
+                commands: vec![to_command_link(command, "Go to implementations".into())],
+                ..Default::default()
+            });
+        }
+    }
+    None
+}
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert_eq!(min_features, vec![SmolStr::new("baz"), SmolStr::new("foo")]);
+fn to_runnable_action(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    runnable: Runnable,
+) -> Option<lsp_ext::CommandLinkGroup> {
+    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id).ok()?;
+    if should_skip_target(&runnable, cargo_spec.as_ref()) {
+        return None;
+    }
 
-        let (subtree, _) =
-            get_token_tree_generated(r#"#![cfg(any(feature = "baz", feature = "foo", unix))]"#);
-        let cfg_expr = parse_cfg(&subtree);
+    let action: &'static _ = runnable.action();
+    to_proto::runnable(snap, file_id, runnable).ok().map(|r| {
+        let mut group = lsp_ext::CommandLinkGroup::default();
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert_eq!(min_features, vec![SmolStr::new("baz")]);
+        if snap.config.hover.run {
+            let run_command = run_single_command(&r, action.run_title);
+            group.commands.push(to_command_link(run_command, r.label.clone()));
+        }
 
-        let (subtree, _) = get_token_tree_generated(r#"#![cfg(foo)]"#);
-        let cfg_expr = parse_cfg(&subtree);
+        if snap.config.hover.debug {
+            let dbg_command = debug_single_command(&r);
+            group.commands.push(to_command_link(dbg_command, r.label));
+        }
+
+        group
+    })
+}
+
+fn prepare_hover_actions(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    actions: &[HoverAction],
+) -> Vec<lsp_ext::CommandLinkGroup> {
+    if snap.config.hover.none() || !snap.config.client_caps.hover_actions {
+        return Vec::new();
+    }
 
-        let mut min_features = vec![];
-        collect_minimal_features_needed(&cfg_expr, &mut min_features);
-        assert!(min_features.is_empty());
+    actions
+        .iter()
+        .filter_map(|it| match it {
+            HoverAction::Implementaion(position) => show_impl_command_link(snap, position),
+            HoverAction::Runnable(r) => to_runnable_action(snap, file_id, r.clone()),
+        })
+        .collect()
+}
+
+fn should_skip_target(runnable: &Runnable, cargo_spec: Option<&CargoTargetSpec>) -> bool {
+    match runnable.kind {
+        RunnableKind::Bin => {
+            // Do not suggest binary run on other target than binary
+            match &cargo_spec {
+                Some(spec) => spec.target_kind != TargetKind::Bin,
+                None => true,
+            }
+        }
+        _ => false,
     }
 }
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 2fbbb4e63..710df1fbd 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -3,13 +3,16 @@ use ra_db::{FileId, FileRange};
 use ra_ide::{
     Assist, CompletionItem, CompletionItemKind, Documentation, FileSystemEdit, Fold, FoldKind,
     FunctionSignature, Highlight, HighlightModifier, HighlightTag, HighlightedRange, Indel,
-    InlayHint, InlayKind, InsertTextFormat, LineIndex, NavigationTarget, ReferenceAccess, Severity,
-    SourceChange, SourceFileEdit, TextEdit,
+    InlayHint, InlayKind, InsertTextFormat, LineIndex, NavigationTarget, ReferenceAccess,
+    ResolvedAssist, Runnable, Severity, SourceChange, SourceFileEdit, TextEdit,
 };
 use ra_syntax::{SyntaxKind, TextRange, TextSize};
 use ra_vfs::LineEndings;
 
-use crate::{lsp_ext, semantic_tokens, world::WorldSnapshot, Result};
+use crate::{
+    cargo_target_spec::CargoTargetSpec, global_state::GlobalStateSnapshot, lsp_ext,
+    semantic_tokens, Result,
+};
 
 pub(crate) fn position(line_index: &LineIndex, offset: TextSize) -> lsp_types::Position {
     let line_col = line_index.line_col(offset);
@@ -382,41 +385,44 @@ pub(crate) fn folding_range(
     }
 }
 
-pub(crate) fn url(world: &WorldSnapshot, file_id: FileId) -> Result<lsp_types::Url> {
-    world.file_id_to_uri(file_id)
+pub(crate) fn url(snap: &GlobalStateSnapshot, file_id: FileId) -> Result<lsp_types::Url> {
+    snap.file_id_to_uri(file_id)
 }
 
 pub(crate) fn versioned_text_document_identifier(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     file_id: FileId,
     version: Option<i64>,
 ) -> Result<lsp_types::VersionedTextDocumentIdentifier> {
-    let res = lsp_types::VersionedTextDocumentIdentifier { uri: url(world, file_id)?, version };
+    let res = lsp_types::VersionedTextDocumentIdentifier { uri: url(snap, file_id)?, version };
     Ok(res)
 }
 
-pub(crate) fn location(world: &WorldSnapshot, frange: FileRange) -> Result<lsp_types::Location> {
-    let url = url(world, frange.file_id)?;
-    let line_index = world.analysis().file_line_index(frange.file_id)?;
+pub(crate) fn location(
+    snap: &GlobalStateSnapshot,
+    frange: FileRange,
+) -> Result<lsp_types::Location> {
+    let url = url(snap, frange.file_id)?;
+    let line_index = snap.analysis().file_line_index(frange.file_id)?;
     let range = range(&line_index, frange.range);
     let loc = lsp_types::Location::new(url, range);
     Ok(loc)
 }
 
 pub(crate) fn location_link(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     src: Option<FileRange>,
     target: NavigationTarget,
 ) -> Result<lsp_types::LocationLink> {
     let origin_selection_range = match src {
         Some(src) => {
-            let line_index = world.analysis().file_line_index(src.file_id)?;
+            let line_index = snap.analysis().file_line_index(src.file_id)?;
             let range = range(&line_index, src.range);
             Some(range)
         }
         None => None,
     };
-    let (target_uri, target_range, target_selection_range) = location_info(world, target)?;
+    let (target_uri, target_range, target_selection_range) = location_info(snap, target)?;
     let res = lsp_types::LocationLink {
         origin_selection_range,
         target_uri,
@@ -427,12 +433,12 @@ pub(crate) fn location_link(
 }
 
 fn location_info(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     target: NavigationTarget,
 ) -> Result<(lsp_types::Url, lsp_types::Range, lsp_types::Range)> {
-    let line_index = world.analysis().file_line_index(target.file_id())?;
+    let line_index = snap.analysis().file_line_index(target.file_id())?;
 
-    let target_uri = url(world, target.file_id())?;
+    let target_uri = url(snap, target.file_id())?;
     let target_range = range(&line_index, target.full_range());
     let target_selection_range =
         target.focus_range().map(|it| range(&line_index, it)).unwrap_or(target_range);
@@ -440,14 +446,14 @@ fn location_info(
 }
 
 pub(crate) fn goto_definition_response(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     src: Option<FileRange>,
     targets: Vec<NavigationTarget>,
 ) -> Result<lsp_types::GotoDefinitionResponse> {
-    if world.config.client_caps.location_link {
+    if snap.config.client_caps.location_link {
         let links = targets
             .into_iter()
-            .map(|nav| location_link(world, src, nav))
+            .map(|nav| location_link(snap, src, nav))
             .collect::<Result<Vec<_>>>()?;
         Ok(links.into())
     } else {
@@ -455,7 +461,7 @@ pub(crate) fn goto_definition_response(
             .into_iter()
             .map(|nav| {
                 location(
-                    world,
+                    snap,
                     FileRange {
                         file_id: nav.file_id(),
                         range: nav.focus_range().unwrap_or(nav.range()),
@@ -468,13 +474,13 @@ pub(crate) fn goto_definition_response(
 }
 
 pub(crate) fn snippet_text_document_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     is_snippet: bool,
     source_file_edit: SourceFileEdit,
 ) -> Result<lsp_ext::SnippetTextDocumentEdit> {
-    let text_document = versioned_text_document_identifier(world, source_file_edit.file_id, None)?;
-    let line_index = world.analysis().file_line_index(source_file_edit.file_id)?;
-    let line_endings = world.file_line_endings(source_file_edit.file_id);
+    let text_document = versioned_text_document_identifier(snap, source_file_edit.file_id, None)?;
+    let line_index = snap.analysis().file_line_index(source_file_edit.file_id)?;
+    let line_endings = snap.file_line_endings(source_file_edit.file_id);
     let edits = source_file_edit
         .edit
         .into_iter()
@@ -484,17 +490,17 @@ pub(crate) fn snippet_text_document_edit(
 }
 
 pub(crate) fn resource_op(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     file_system_edit: FileSystemEdit,
 ) -> Result<lsp_types::ResourceOp> {
     let res = match file_system_edit {
         FileSystemEdit::CreateFile { source_root, path } => {
-            let uri = world.path_to_uri(source_root, &path)?;
+            let uri = snap.path_to_uri(source_root, &path)?;
             lsp_types::ResourceOp::Create(lsp_types::CreateFile { uri, options: None })
         }
         FileSystemEdit::MoveFile { src, dst_source_root, dst_path } => {
-            let old_uri = world.file_id_to_uri(src)?;
-            let new_uri = world.path_to_uri(dst_source_root, &dst_path)?;
+            let old_uri = snap.file_id_to_uri(src)?;
+            let new_uri = snap.path_to_uri(dst_source_root, &dst_path)?;
             lsp_types::ResourceOp::Rename(lsp_types::RenameFile { old_uri, new_uri, options: None })
         }
     };
@@ -502,16 +508,16 @@ pub(crate) fn resource_op(
 }
 
 pub(crate) fn snippet_workspace_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     source_change: SourceChange,
 ) -> Result<lsp_ext::SnippetWorkspaceEdit> {
     let mut document_changes: Vec<lsp_ext::SnippetDocumentChangeOperation> = Vec::new();
     for op in source_change.file_system_edits {
-        let op = resource_op(&world, op)?;
+        let op = resource_op(&snap, op)?;
         document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Op(op));
     }
     for edit in source_change.source_file_edits {
-        let edit = snippet_text_document_edit(&world, source_change.is_snippet, edit)?;
+        let edit = snippet_text_document_edit(&snap, source_change.is_snippet, edit)?;
         document_changes.push(lsp_ext::SnippetDocumentChangeOperation::Edit(edit));
     }
     let workspace_edit =
@@ -520,11 +526,11 @@ pub(crate) fn snippet_workspace_edit(
 }
 
 pub(crate) fn workspace_edit(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     source_change: SourceChange,
 ) -> Result<lsp_types::WorkspaceEdit> {
     assert!(!source_change.is_snippet);
-    snippet_workspace_edit(world, source_change).map(|it| it.into())
+    snippet_workspace_edit(snap, source_change).map(|it| it.into())
 }
 
 impl From<lsp_ext::SnippetWorkspaceEdit> for lsp_types::WorkspaceEdit {
@@ -563,13 +569,13 @@ impl From<lsp_ext::SnippetWorkspaceEdit> for lsp_types::WorkspaceEdit {
 }
 
 pub fn call_hierarchy_item(
-    world: &WorldSnapshot,
+    snap: &GlobalStateSnapshot,
     target: NavigationTarget,
 ) -> Result<lsp_types::CallHierarchyItem> {
     let name = target.name().to_string();
     let detail = target.description().map(|it| it.to_string());
     let kind = symbol_kind(target.kind());
-    let (uri, range, selection_range) = location_info(world, target)?;
+    let (uri, range, selection_range) = location_info(snap, target)?;
     Ok(lsp_types::CallHierarchyItem { name, kind, tags: None, detail, uri, range, selection_range })
 }
 
@@ -617,13 +623,56 @@ fn main() <fold>{
     }
 }
 
-pub(crate) fn code_action(world: &WorldSnapshot, assist: Assist) -> Result<lsp_ext::CodeAction> {
+pub(crate) fn unresolved_code_action(
+    snap: &GlobalStateSnapshot,
+    assist: Assist,
+    index: usize,
+) -> Result<lsp_ext::CodeAction> {
     let res = lsp_ext::CodeAction {
         title: assist.label,
-        group: if world.config.client_caps.code_action_group { assist.group_label } else { None },
+        id: Some(format!("{}:{}", assist.id.0.to_owned(), index.to_string())),
+        group: assist.group.filter(|_| snap.config.client_caps.code_action_group).map(|gr| gr.0),
         kind: Some(String::new()),
-        edit: Some(snippet_workspace_edit(world, assist.source_change)?),
+        edit: None,
         command: None,
     };
     Ok(res)
 }
+
+pub(crate) fn resolved_code_action(
+    snap: &GlobalStateSnapshot,
+    assist: ResolvedAssist,
+) -> Result<lsp_ext::CodeAction> {
+    let change = assist.source_change;
+    unresolved_code_action(snap, assist.assist, 0).and_then(|it| {
+        Ok(lsp_ext::CodeAction {
+            id: None,
+            edit: Some(snippet_workspace_edit(snap, change)?),
+            ..it
+        })
+    })
+}
+
+pub(crate) fn runnable(
+    snap: &GlobalStateSnapshot,
+    file_id: FileId,
+    runnable: Runnable,
+) -> Result<lsp_ext::Runnable> {
+    let spec = CargoTargetSpec::for_file(snap, file_id)?;
+    let target = spec.as_ref().map(|s| s.target.clone());
+    let (cargo_args, executable_args) =
+        CargoTargetSpec::runnable_args(spec, &runnable.kind, &runnable.cfg_exprs)?;
+    let label = runnable.label(target);
+    let location = location_link(snap, None, runnable.nav)?;
+
+    Ok(lsp_ext::Runnable {
+        label,
+        location: Some(location),
+        kind: lsp_ext::RunnableKind::Cargo,
+        args: lsp_ext::CargoRunnable {
+            workspace_root: snap.workspace_root_for(file_id).map(|root| root.to_owned()),
+            cargo_args,
+            executable_args,
+        },
+    })
+}
diff --git a/crates/rust-analyzer/tests/heavy_tests/main.rs b/crates/rust-analyzer/tests/heavy_tests/main.rs
index 405ddb362..0e2a83c6a 100644
--- a/crates/rust-analyzer/tests/heavy_tests/main.rs
+++ b/crates/rust-analyzer/tests/heavy_tests/main.rs
@@ -4,9 +4,7 @@ use std::{collections::HashMap, path::PathBuf, time::Instant};
 
 use lsp_types::{
     notification::DidOpenTextDocument,
-    request::{
-        CodeActionRequest, Completion, Formatting, GotoDefinition, GotoTypeDefinition, HoverRequest,
-    },
+    request::{CodeActionRequest, Completion, Formatting, GotoTypeDefinition, HoverRequest},
     CodeActionContext, CodeActionParams, CompletionParams, DidOpenTextDocumentParams,
     DocumentFormattingParams, FormattingOptions, GotoDefinitionParams, HoverParams,
     PartialResultParams, Position, Range, TextDocumentItem, TextDocumentPositionParams,
@@ -59,52 +57,6 @@ use std::collections::Spam;
 }
 
 #[test]
-fn test_runnables_no_project() {
-    if skip_slow_tests() {
-        return;
-    }
-
-    let server = project(
-        r"
-//- lib.rs
-#[test]
-fn foo() {
-}
-",
-    );
-    server.wait_until_workspace_is_loaded();
-    server.request::<Runnables>(
-        RunnablesParams { text_document: server.doc_id("lib.rs"), position: None },
-        json!([
-          {
-            "args": [ "test" ],
-            "extraArgs": [ "foo", "--nocapture" ],
-            "bin": "cargo",
-            "env": { "RUST_BACKTRACE": "short" },
-            "cwd": null,
-            "label": "test foo",
-            "range": {
-              "end": { "character": 1, "line": 2 },
-              "start": { "character": 0, "line": 0 }
-            }
-          },
-          {
-            "args": ["check", "--workspace"],
-            "extraArgs": [],
-            "bin": "cargo",
-            "env": {},
-            "cwd": null,
-            "label": "cargo check --workspace",
-            "range": {
-              "end": { "character": 0, "line": 0 },
-              "start": { "character": 0, "line": 0 }
-            }
-          }
-        ]),
-    );
-}
-
-#[test]
 fn test_runnables_project() {
     if skip_slow_tests() {
         return;
@@ -138,42 +90,44 @@ fn main() {}
     server.request::<Runnables>(
         RunnablesParams { text_document: server.doc_id("foo/tests/spam.rs"), position: None },
         json!([
-            {
-              "args": [ "test", "--package", "foo", "--test", "spam" ],
-              "extraArgs": [ "test_eggs", "--exact", "--nocapture" ],
-              "bin": "cargo",
-              "env": { "RUST_BACKTRACE": "short" },
-              "label": "test test_eggs",
-              "range": {
+          {
+            "args": {
+              "cargoArgs": ["test", "--package", "foo", "--test", "spam"],
+              "executableArgs": ["test_eggs", "--exact", "--nocapture"],
+              "workspaceRoot": server.path().join("foo")
+            },
+            "kind": "cargo",
+            "label": "test test_eggs",
+            "location": {
+              "targetRange": {
                 "end": { "character": 17, "line": 1 },
                 "start": { "character": 0, "line": 0 }
               },
-              "cwd": server.path().join("foo")
-            },
-            {
-              "args": [ "check", "--package", "foo" ],
-              "extraArgs": [],
-              "bin": "cargo",
-              "env": {},
-              "label": "cargo check -p foo",
-              "range": {
-                "end": { "character": 0, "line": 0 },
-                "start": { "character": 0, "line": 0 }
+              "targetSelectionRange": {
+                "end": { "character": 12, "line": 1 },
+                "start": { "character": 3, "line": 1 }
               },
-              "cwd": server.path().join("foo")
-            },
-            {
-              "args": [ "test", "--package", "foo" ],
-              "extraArgs": [],
-              "bin": "cargo",
-              "env": {},
-              "label": "cargo test -p foo",
-              "range": {
-                "end": { "character": 0, "line": 0 },
-                "start": { "character": 0, "line": 0 }
-              },
-              "cwd": server.path().join("foo")
+              "targetUri": "file:///[..]/tests/spam.rs"
             }
+          },
+          {
+            "args": {
+              "cargoArgs": ["check", "--package", "foo"],
+              "executableArgs": [],
+              "workspaceRoot": server.path().join("foo")
+            },
+            "kind": "cargo",
+            "label": "cargo check -p foo"
+          },
+          {
+            "args": {
+              "cargoArgs": ["test", "--package", "foo"],
+              "executableArgs": [],
+              "workspaceRoot": server.path().join("foo")
+            },
+            "kind": "cargo",
+            "label": "cargo test -p foo"
+          }
         ]),
     );
 }
@@ -342,6 +296,7 @@ fn main() {}
                 }
               ]
             },
+            "kind": "quickfix",
             "title": "Create module"
         }]),
     );
@@ -374,8 +329,7 @@ fn test_missing_module_code_action_in_json_project() {
             "root_module": path.join("src/lib.rs"),
             "deps": [],
             "edition": "2015",
-            "atom_cfgs": [],
-            "key_value_cfgs": {}
+            "cfg": [ "cfg_atom_1", "feature=cfg_1"],
         } ]
     });
 
@@ -413,6 +367,7 @@ fn main() {{}}
                 }
               ]
             },
+            "kind": "quickfix",
             "title": "Create module"
         }]),
     );
@@ -550,6 +505,10 @@ fn main() {
     println!("cargo:rerun-if-changed=build.rs");
 }
 //- src/main.rs
+#[rustc_builtin_macro] macro_rules! include {}
+#[rustc_builtin_macro] macro_rules! concat {}
+#[rustc_builtin_macro] macro_rules! env {}
+
 include!(concat!(env!("OUT_DIR"), "/hello.rs"));
 
 #[cfg(atom_cfg)]
@@ -564,10 +523,8 @@ struct B;
 fn main() {
     let va = A;
     let vb = B;
-    message();
+    let should_be_str = message();
 }
-
-fn main() { message(); }
 "###,
     )
     .with_config(|config| {
@@ -575,54 +532,35 @@ fn main() { message(); }
     })
     .server();
     server.wait_until_workspace_is_loaded();
-    let res = server.send_request::<GotoDefinition>(GotoDefinitionParams {
+    let res = server.send_request::<HoverRequest>(HoverParams {
         text_document_position_params: TextDocumentPositionParams::new(
             server.doc_id("src/main.rs"),
-            Position::new(14, 8),
+            Position::new(18, 10),
         ),
         work_done_progress_params: Default::default(),
-        partial_result_params: Default::default(),
     });
-    assert!(format!("{}", res).contains("hello.rs"));
+    assert!(res.to_string().contains("&str"));
     server.request::<GotoTypeDefinition>(
         GotoDefinitionParams {
             text_document_position_params: TextDocumentPositionParams::new(
                 server.doc_id("src/main.rs"),
-                Position::new(12, 9),
+                Position::new(16, 9),
             ),
             work_done_progress_params: Default::default(),
             partial_result_params: Default::default(),
         },
         json!([{
             "originSelectionRange": {
-                "end": {
-                    "character": 10,
-                    "line": 12
-                },
-                "start": {
-                    "character": 8,
-                    "line": 12
-                }
+                "end": { "character": 10, "line": 16 },
+                "start": { "character": 8, "line": 16 }
             },
             "targetRange": {
-                "end": {
-                    "character": 9,
-                    "line": 3
-                },
-                "start": {
-                    "character": 0,
-                    "line": 2
-                }
+                "end": { "character": 9, "line": 7 },
+                "start": { "character": 0, "line": 6 }
             },
             "targetSelectionRange": {
-                "end": {
-                    "character": 8,
-                    "line": 3
-                },
-                "start": {
-                    "character": 7,
-                    "line": 3
-                }
+                "end": { "character": 8, "line": 7 },
+                "start": { "character": 7, "line": 7 }
             },
             "targetUri": "file:///[..]src/main.rs"
         }]),
@@ -631,41 +569,23 @@ fn main() { message(); }
         GotoDefinitionParams {
             text_document_position_params: TextDocumentPositionParams::new(
                 server.doc_id("src/main.rs"),
-                Position::new(13, 9),
+                Position::new(17, 9),
             ),
             work_done_progress_params: Default::default(),
             partial_result_params: Default::default(),
         },
         json!([{
             "originSelectionRange": {
-                "end": {
-                    "character": 10,
-                    "line": 13
-                },
-                "start": {
-                    "character": 8,
-                    "line":13
-                }
+                "end": { "character": 10, "line": 17 },
+                "start": { "character": 8, "line": 17 }
             },
             "targetRange": {
-                "end": {
-                    "character": 9,
-                    "line": 7
-                },
-                "start": {
-                    "character": 0,
-                    "line":6
-                }
+                "end": { "character": 9, "line": 11 },
+                "start": { "character": 0, "line":10 }
             },
             "targetSelectionRange": {
-                "end": {
-                    "character": 8,
-                    "line": 7
-                },
-                "start": {
-                    "character": 7,
-                    "line": 7
-                }
+                "end": { "character": 8, "line": 11 },
+                "start": { "character": 7, "line": 11 }
             },
             "targetUri": "file:///[..]src/main.rs"
         }]),
diff --git a/crates/rust-analyzer/tests/heavy_tests/support.rs b/crates/rust-analyzer/tests/heavy_tests/support.rs
index 66a6f4d54..30d03b622 100644
--- a/crates/rust-analyzer/tests/heavy_tests/support.rs
+++ b/crates/rust-analyzer/tests/heavy_tests/support.rs
@@ -19,8 +19,9 @@ use serde_json::{to_string_pretty, Value};
 use tempfile::TempDir;
 use test_utils::{find_mismatch, parse_fixture};
 
+use ra_project_model::ProjectManifest;
 use rust_analyzer::{
-    config::{ClientCapsConfig, Config},
+    config::{ClientCapsConfig, Config, LinkedProject},
     main_loop,
 };
 
@@ -42,7 +43,7 @@ impl<'a> Project<'a> {
         self
     }
 
-    pub fn root(mut self, path: &str) -> Project<'a> {
+    pub(crate) fn root(mut self, path: &str) -> Project<'a> {
         self.roots.push(path.into());
         self
     }
@@ -74,7 +75,16 @@ impl<'a> Project<'a> {
             paths.push((path, entry.text));
         }
 
-        let roots = self.roots.into_iter().map(|root| tmp_dir.path().join(root)).collect();
+        let mut roots =
+            self.roots.into_iter().map(|root| tmp_dir.path().join(root)).collect::<Vec<_>>();
+        if roots.is_empty() {
+            roots.push(tmp_dir.path().to_path_buf());
+        }
+        let linked_projects = roots
+            .into_iter()
+            .map(|it| ProjectManifest::discover_single(&it).unwrap())
+            .map(LinkedProject::from)
+            .collect::<Vec<_>>();
 
         let mut config = Config {
             client_caps: ClientCapsConfig {
@@ -84,6 +94,7 @@ impl<'a> Project<'a> {
                 ..Default::default()
             },
             with_sysroot: self.with_sysroot,
+            linked_projects,
             ..Config::default()
         };
 
@@ -91,7 +102,7 @@ impl<'a> Project<'a> {
             f(&mut config)
         }
 
-        Server::new(tmp_dir, config, roots, paths)
+        Server::new(tmp_dir, config, paths)
     }
 }
 
@@ -109,20 +120,12 @@ pub struct Server {
 }
 
 impl Server {
-    fn new(
-        dir: TempDir,
-        config: Config,
-        roots: Vec<PathBuf>,
-        files: Vec<(PathBuf, String)>,
-    ) -> Server {
-        let path = dir.path().to_path_buf();
-
-        let roots = if roots.is_empty() { vec![path] } else { roots };
+    fn new(dir: TempDir, config: Config, files: Vec<(PathBuf, String)>) -> Server {
         let (connection, client) = Connection::memory();
 
         let _thread = jod_thread::Builder::new()
             .name("test server".to_string())
-            .spawn(move || main_loop(roots, config, connection).unwrap())
+            .spawn(move || main_loop(config, connection).unwrap())
             .expect("failed to spawn a thread");
 
         let res =
diff --git a/crates/stdx/src/lib.rs b/crates/stdx/src/lib.rs
index 71a57fba2..c0356344c 100644
--- a/crates/stdx/src/lib.rs
+++ b/crates/stdx/src/lib.rs
@@ -124,3 +124,8 @@ pub fn replace(buf: &mut String, from: char, to: &str) {
     // FIXME: do this in place.
     *buf = buf.replace(from, to)
 }
+
+pub fn split1(haystack: &str, delim: char) -> Option<(&str, &str)> {
+    let idx = haystack.find(delim)?;
+    Some((&haystack[..idx], &haystack[idx + delim.len_utf8()..]))
+}
diff --git a/crates/test_utils/Cargo.toml b/crates/test_utils/Cargo.toml
index 4d185b01c..8840bf36a 100644
--- a/crates/test_utils/Cargo.toml
+++ b/crates/test_utils/Cargo.toml
@@ -14,4 +14,5 @@ serde_json = "1.0.48"
 relative-path = "1.0.0"
 rustc-hash = "1.1.0"
 
-ra_cfg = { path = "../ra_cfg" }
\ No newline at end of file
+ra_cfg = { path = "../ra_cfg" }
+stdx = { path = "../stdx" }
\ No newline at end of file
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 1bd97215c..2141bfc20 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -15,6 +15,7 @@ use std::{
 };
 
 pub use ra_cfg::CfgOptions;
+use stdx::split1;
 
 pub use relative_path::{RelativePath, RelativePathBuf};
 pub use rustc_hash::FxHashMap;
@@ -332,11 +333,6 @@ fn parse_meta(meta: &str) -> FixtureMeta {
     FixtureMeta::File(FileMeta { path, crate_name: krate, deps, edition, cfg, env })
 }
 
-fn split1(haystack: &str, delim: char) -> Option<(&str, &str)> {
-    let idx = haystack.find(delim)?;
-    Some((&haystack[..idx], &haystack[idx + delim.len_utf8()..]))
-}
-
 /// Adjusts the indentation of the first line to the minimum indentation of the rest of the lines.
 /// This allows fixtures to start off in a different indentation, e.g. to align the first line with
 /// the other lines visually:
diff --git a/docs/dev/README.md b/docs/dev/README.md
index 65cc9fc12..ef5ffbf59 100644
--- a/docs/dev/README.md
+++ b/docs/dev/README.md
@@ -30,7 +30,7 @@ https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
 
 * [good-first-issue](https://github.com/rust-analyzer/rust-analyzer/labels/good%20first%20issue)
   are good issues to get into the project.
-* [E-mentor](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-mentor)
+* [E-has-instructions](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-has-instructions)
   issues have links to the code in question and tests.
 * [E-easy](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy),
   [E-medium](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-medium),
@@ -55,7 +55,7 @@ You can run `cargo xtask install-pre-commit-hook` to install git-hook to run rus
 All Rust code lives in the `crates` top-level directory, and is organized as a
 single Cargo workspace. The `editors` top-level directory contains code for
 integrating with editors. Currently, it contains the plugin for VS Code (in
-typescript). The `docs` top-level directory contains both developer and user
+TypeScript). The `docs` top-level directory contains both developer and user
 documentation.
 
 We have some automation infra in Rust in the `xtask` package. It contains
@@ -79,8 +79,8 @@ possible. There's **"Run Extension (Debug Build)"** launch configuration for thi
 In general, I use one of the following workflows for fixing bugs and
 implementing features.
 
-If the problem concerns only internal parts of rust-analyzer (ie, I don't need
-to touch `rust-analyzer` crate or typescript code), there is a unit-test for it.
+If the problem concerns only internal parts of rust-analyzer (i.e. I don't need
+to touch `rust-analyzer` crate or TypeScript code), there is a unit-test for it.
 So, I use **Rust Analyzer: Run** action in VS Code to run this single test, and
 then just do printf-driven development/debugging. As a sanity check after I'm
 done, I use `cargo xtask install --server` and **Reload Window** action in VS
@@ -117,6 +117,203 @@ Additionally, I use `cargo run --release -p rust-analyzer -- analysis-stats
 path/to/some/rust/crate` to run a batch analysis. This is primarily useful for
 performance optimizations, or for bug minimization.
 
+# Code Style & Review Process
+
+Our approach to "clean code" is two fold:
+
+* We generally don't block PRs on style changes.
+* At the same time, all code in rust-analyzer is constantly refactored.
+
+It is explicitly OK for reviewer to flag only some nits in the PR, and than send a follow up cleanup PR for things which are easier to explain by example, cc-ing the original author.
+Sending small cleanup PRs (like rename a single local variable) is encouraged.
+
+## Scale of Changes
+
+Everyone knows that it's better to send small & focused pull requests.
+The problem is, sometimes you *have* to, eg, rewrite the whole compiler, and that just doesn't fit into a set of isolated PRs.
+
+The main thing too keep an eye on is the boundaries between various components.
+There are three kinds of changes:
+
+1. Internals of a single component are changed.
+   Specifically, you don't change any `pub` items.
+   A good example here would be an addition of a new assist.
+
+2. API of a component is expanded.
+   Specifically, you add a new `pub` function which wasn't there before.
+   A good example here would be expansion of assist API, for example, to implement lazy assists or assists groups.
+
+3. A new dependency between components is introduced.
+   Specifically, you add a `pub use` reexport from another crate or you add a new line to `[dependencies]` section of `Cargo.toml`.
+   A good example here would be adding reference search capability to the assists crates.
+
+For the first group, the change is generally merged as long as:
+
+* it works for the happy case,
+* it has tests,
+* it doesn't panic for unhappy case.
+
+For the second group, the change would be subjected to quite a bit of scrutiny and iteration.
+The new API needs to be right (or at least easy to change later).
+The actual implementation doesn't matter that much.
+It's very important to minimize the amount of changed lines of code for changes of the second kind.
+Often, you start doing change of the first kind, only to realise that you need to elevate to a change of the second kind.
+In this case, we'll probably ask you to split API changes into a separate PR.
+
+Changes of the third group should be pretty rare, so we don't specify any specific process for them.
+That said, adding an innocent-looking `pub use` is a very simple way to break encapsulation, keep an eye on it!
+
+Note: if you enjoyed this abstract hand-waving about boundaries, you might appreciate
+https://www.tedinski.com/2018/02/06/system-boundaries.html
+
+## Order of Imports
+
+We separate import groups with blank lines
+
+```rust
+mod x;
+mod y;
+
+use std::{ ... }
+
+use crate_foo::{ ... }
+use crate_bar::{ ... }
+
+use crate::{}
+
+use super::{} // but prefer `use crate::`
+```
+
+## Import Style
+
+Items from `hir` and `ast` should be used qualified:
+
+```rust
+// Good
+use ra_syntax::ast;
+
+fn frobnicate(func: hir::Function, strukt: ast::StructDef) {}
+
+// Not as good
+use hir::Function;
+use ra_syntax::ast::StructDef;
+
+fn frobnicate(func: Function, strukt: StructDef) {}
+```
+
+Avoid local `use MyEnum::*` imports.
+
+Prefer `use crate::foo::bar` to `use super::bar`.
+
+## Order of Items
+
+Optimize for the reader who sees the file for the first time, and wants to get the general idea about what's going on.
+People read things from top to bottom, so place most important things first.
+
+Specifically, if all items except one are private, always put the non-private item on top.
+
+Put `struct`s and `enum`s first, functions and impls last.
+
+Do
+
+```rust
+// Good
+struct Foo {
+  bars: Vec<Bar>
+}
+
+struct Bar;
+```
+
+rather than
+
+```rust
+// Not as good
+struct Bar;
+
+struct Foo {
+  bars: Vec<Bar>
+}
+```
+
+## Documentation
+
+For `.md` and `.adoc` files, prefer a sentence-per-line format, don't wrap lines.
+If the line is too long, you want to split the sentence in two :-)
+
+## Preconditions
+
+Function preconditions should generally be expressed in types and provided by the caller (rather than checked by callee):
+
+```rust
+// Good
+fn frbonicate(walrus: Walrus) {
+  ...
+}
+
+// Not as good
+fn frobnicate(walrus: Option<Walrus>) {
+  let walrus = match walrus {
+    Some(it) => it,
+    None => return,
+  };
+  ...
+}
+```
+
+## Commit Style
+
+We don't have specific rules around git history hygiene.
+Maintaining clean git history is encouraged, but not enforced.
+We use rebase workflow, it's OK to rewrite history during PR review process.
+
+Avoid @mentioning people in commit messages, as such messages create a lot of duplicate notification traffic during rebases.
+
+# Architecture Invariants
+
+This section tries to document high-level design constraints, which are not
+always obvious from the low-level code.
+
+## Incomplete syntax trees
+
+Syntax trees are by design incomplete and do not enforce well-formedness.
+If ast method returns an `Option`, it *can* be `None` at runtime, even if this is forbidden by the grammar.
+
+## LSP independence
+
+rust-analyzer is independent from LSP.
+It provides features for a hypothetical perfect Rust-specific IDE client.
+Internal representations are lowered to LSP in the `rust-analyzer` crate (the only crate which is allowed to use LSP types).
+
+## IDE/Compiler split
+
+There's a semi-hard split between "compiler" and "IDE", at the `ra_hir` crate.
+Compiler derives new facts about source code.
+It explicitly acknowledges that not all info is available (i.e. you can't look at types during name resolution).
+
+IDE assumes that all information is available at all times.
+
+IDE should use only types from `ra_hir`, and should not depend on the underling compiler types.
+`ra_hir` is a facade.
+
+## IDE API
+
+The main IDE crate (`ra_ide`) uses "Plain Old Data" for the API.
+Rather than talking in definitions and references, it talks in Strings and textual offsets.
+In general, API is centered around UI concerns -- the result of the call is what the user sees in the editor, and not what the compiler sees underneath.
+The results are 100% Rust specific though.
+
+## Parser Tests
+
+Test for parser (`ra_parser`) live in `ra_syntax` crate (see `test_data` direcotory).
+There are two kinds of tests:
+
+* Manually written test cases in `parser/ok` and `parser/err`
+* "Inline" tests in `parser/inline` (these are generated) from comments in `ra_parser` crate.
+
+The purpose of inline tests is not to achieve full coverage by test cases, but to explain to the reader of the code what each particular `if` and `match` is responsible for.
+If you are tempted to add a large inline test, it might be a good idea to leave only the simplest example in place, and move the test to a manual `parser/ok` test.
+
 # Logging
 
 Logging is done by both rust-analyzer and VS Code, so it might be tricky to
@@ -159,8 +356,8 @@ There's also two VS Code commands which might be of interest:
   rust code that it refers to and the rust editor will also highlight the proper
   text range.
 
-  If you press <kbd>Ctrl</kbd> (i.e. trigger goto definition) in the inspected
-  Rust source file the syntax tree read-only editor should scroll to and select the
+  If you trigger Go to Definition in the inspected Rust source file,
+  the syntax tree read-only editor should scroll to and select the
   appropriate syntax node token.
 
   ![demo](https://user-images.githubusercontent.com/36276403/78225773-6636a480-74d3-11ea-9d9f-1c9d42da03b0.png)
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index c57a93f12..a0847dad3 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -97,6 +97,30 @@ Invoking code action at this position will yield two code actions for importing
 * Is a fixed two-level structure enough?
 * Should we devise a general way to encode custom interaction protocols for GUI refactorings?
 
+## Lazy assists with `ResolveCodeAction`
+
+**Issue:** https://github.com/microsoft/language-server-protocol/issues/787
+
+**Client Capability** `{ "resolveCodeAction": boolean }`
+
+If this capability is set, the assists will be computed lazily. Thus `CodeAction` returned from the server will only contain `id` but not `edit` or `command` fields. The only exclusion from the rule is the diagnostic edits.
+
+After the client got the id, it should then call `experimental/resolveCodeAction` command on the server and provide the following payload:
+
+```typescript
+interface ResolveCodeActionParams {
+    id: string;
+    codeActionParams: lc.CodeActionParams;
+}
+```
+
+As a result of the command call the client will get the respective workspace edit (`lc.WorkspaceEdit`).
+
+### Unresolved Questions
+
+* Apply smarter filtering for ids?
+* Upon `resolveCodeAction` command only call the assits which should be resolved and not all of them?
+
 ## Parent Module
 
 **Issue:** https://github.com/microsoft/language-server-protocol/issues/1002
@@ -311,6 +335,50 @@ Moreover, it would be cool if editors didn't need to implement even basic langua
   This is how `SelectionRange` request works.
 * Alternatively, should we perhaps flag certain `SelectionRange`s as being brace pairs?
 
+## Runnables
+
+**Issue:** https://github.com/microsoft/language-server-protocol/issues/944
+
+**Server Capability:** `{ "runnables": { "kinds": string[] } }`
+
+This request is send from client to server to get the list of things that can be run (tests, binaries, `cargo check -p`).
+
+**Method:** `experimental/runnables`
+
+**Request:**
+
+```typescript
+interface RunnablesParams {
+    textDocument: TextDocumentIdentifier;
+    /// If null, compute runnables for the whole file.
+    position?: Position;
+}
+```
+
+**Response:** `Runnable[]`
+
+```typescript
+interface Runnable {
+    label: string;
+    /// If this Runnable is associated with a specific function/module, etc, the location of this item
+    location?: LocationLink;
+    /// Running things is necessary technology specific, `kind` needs to be advertised via server capabilities,
+    // the type of `args` is specific to `kind`. The actual running is handled by the client.
+    kind: string;
+    args: any;
+}
+```
+
+rust-analyzer supports only one `kind`, `"cargo"`. The `args` for `"cargo"` look like this:
+
+```typescript
+{
+    workspaceRoot?: string;
+    cargoArgs: string[];
+    executableArgs: string[];
+}
+```
+
 ## Analyzer Status
 
 **Method:** `rust-analyzer/analyzerStatus`
@@ -400,38 +468,40 @@ interface InlayHint {
 }
 ```
 
-## Runnables
-
-**Method:** `rust-analyzer/runnables`
+## Hover Actions
 
-This request is send from client to server to get the list of things that can be run (tests, binaries, `cargo check -p`).
-Note that we plan to move this request to `experimental/runnables`, as it is not really Rust-specific, but the current API is not necessary the right one.
-Upstream issue: https://github.com/microsoft/language-server-protocol/issues/944
+**Client Capability:** `{ "hoverActions": boolean }`
 
-**Request:**
+If this capability is set, `Hover` request returned from the server might contain an additional field, `actions`:
 
 ```typescript
-interface RunnablesParams {
-    textDocument: TextDocumentIdentifier;
-    /// If null, compute runnables for the whole file.
-    position?: Position;
+interface Hover {
+    ...
+    actions?: CommandLinkGroup[];
 }
-```
 
-**Response:** `Runnable[]`
+interface CommandLink extends Command {
+    /**
+     * A tooltip for the command, when represented in the UI.
+     */
+    tooltip?: string;
+}
 
-```typescript
-interface Runnable {
-    /// The range this runnable is applicable for.
-    range: lc.Range;
-    /// The label to show in the UI.
-    label: string;
-    /// The following fields describe a process to spawn.
-    bin: string;
-    args: string[];
-    /// Args for cargo after `--`.
-    extraArgs: string[];
-    env: { [key: string]: string };
-    cwd: string | null;
+interface CommandLinkGroup {
+    title?: string;
+    commands: CommandLink[];
 }
 ```
+
+Such actions on the client side are appended to a hover bottom as command links:
+```
+  +-----------------------------+
+  | Hover content               |
+  |                             |
+  +-----------------------------+
+  | _Action1_ | _Action2_       |  <- first group, no TITLE
+  +-----------------------------+
+  | TITLE _Action1_ | _Action2_ |  <- second group
+  +-----------------------------+
+  ...
+```
\ No newline at end of file
diff --git a/docs/user/generated_assists.adoc b/docs/user/generated_assists.adoc
deleted file mode 100644
index 4d2fb31d4..000000000
--- a/docs/user/generated_assists.adoc
+++ /dev/null
@@ -1,1015 +0,0 @@
-[discrete]
-=== `add_custom_impl`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_custom_impl.rs#L14[add_custom_impl.rs]
-
-Adds impl block for derived trait.
-
-.Before
-```rust
-#[derive(Deb┃ug, Display)]
-struct S;
-```
-
-.After
-```rust
-#[derive(Display)]
-struct S;
-
-impl Debug for S {
-    $0
-}
-```
-
-
-[discrete]
-=== `add_derive`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_derive.rs#L9[add_derive.rs]
-
-Adds a new `#[derive()]` clause to a struct or enum.
-
-.Before
-```rust
-struct Point {
-    x: u32,
-    y: u32,┃
-}
-```
-
-.After
-```rust
-#[derive($0)]
-struct Point {
-    x: u32,
-    y: u32,
-}
-```
-
-
-[discrete]
-=== `add_explicit_type`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_explicit_type.rs#L9[add_explicit_type.rs]
-
-Specify type for a let binding.
-
-.Before
-```rust
-fn main() {
-    let x┃ = 92;
-}
-```
-
-.After
-```rust
-fn main() {
-    let x: i32 = 92;
-}
-```
-
-
-[discrete]
-=== `add_from_impl_for_enum`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_from_impl_for_enum.rs#L7[add_from_impl_for_enum.rs]
-
-Adds a From impl for an enum variant with one tuple field.
-
-.Before
-```rust
-enum A { ┃One(u32) }
-```
-
-.After
-```rust
-enum A { One(u32) }
-
-impl From<u32> for A {
-    fn from(v: u32) -> Self {
-        A::One(v)
-    }
-}
-```
-
-
-[discrete]
-=== `add_function`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_function.rs#L19[add_function.rs]
-
-Adds a stub function with a signature matching the function under the cursor.
-
-.Before
-```rust
-struct Baz;
-fn baz() -> Baz { Baz }
-fn foo() {
-    bar┃("", baz());
-}
-
-```
-
-.After
-```rust
-struct Baz;
-fn baz() -> Baz { Baz }
-fn foo() {
-    bar("", baz());
-}
-
-fn bar(arg: &str, baz: Baz) {
-    ${0:todo!()}
-}
-
-```
-
-
-[discrete]
-=== `add_hash`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/raw_string.rs#L65[raw_string.rs]
-
-Adds a hash to a raw string literal.
-
-.Before
-```rust
-fn main() {
-    r#"Hello,┃ World!"#;
-}
-```
-
-.After
-```rust
-fn main() {
-    r##"Hello, World!"##;
-}
-```
-
-
-[discrete]
-=== `add_impl`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_impl.rs#L6[add_impl.rs]
-
-Adds a new inherent impl for a type.
-
-.Before
-```rust
-struct Ctx<T: Clone> {
-    data: T,┃
-}
-```
-
-.After
-```rust
-struct Ctx<T: Clone> {
-    data: T,
-}
-
-impl<T: Clone> Ctx<T> {
-    $0
-}
-```
-
-
-[discrete]
-=== `add_impl_default_members`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_missing_impl_members.rs#L64[add_missing_impl_members.rs]
-
-Adds scaffold for overriding default impl members.
-
-.Before
-```rust
-trait Trait {
-    Type X;
-    fn foo(&self);
-    fn bar(&self) {}
-}
-
-impl Trait for () {
-    Type X = ();
-    fn foo(&self) {}┃
-
-}
-```
-
-.After
-```rust
-trait Trait {
-    Type X;
-    fn foo(&self);
-    fn bar(&self) {}
-}
-
-impl Trait for () {
-    Type X = ();
-    fn foo(&self) {}
-    $0fn bar(&self) {}
-
-}
-```
-
-
-[discrete]
-=== `add_impl_missing_members`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_missing_impl_members.rs#L24[add_missing_impl_members.rs]
-
-Adds scaffold for required impl members.
-
-.Before
-```rust
-trait Trait<T> {
-    Type X;
-    fn foo(&self) -> T;
-    fn bar(&self) {}
-}
-
-impl Trait<u32> for () {┃
-
-}
-```
-
-.After
-```rust
-trait Trait<T> {
-    Type X;
-    fn foo(&self) -> T;
-    fn bar(&self) {}
-}
-
-impl Trait<u32> for () {
-    fn foo(&self) -> u32 {
-        ${0:todo!()}
-    }
-
-}
-```
-
-
-[discrete]
-=== `add_new`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_new.rs#L12[add_new.rs]
-
-Adds a new inherent impl for a type.
-
-.Before
-```rust
-struct Ctx<T: Clone> {
-     data: T,┃
-}
-```
-
-.After
-```rust
-struct Ctx<T: Clone> {
-     data: T,
-}
-
-impl<T: Clone> Ctx<T> {
-    fn $0new(data: T) -> Self { Self { data } }
-}
-
-```
-
-
-[discrete]
-=== `add_turbo_fish`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/add_turbo_fish.rs#L10[add_turbo_fish.rs]
-
-Adds `::<_>` to a call of a generic method or function.
-
-.Before
-```rust
-fn make<T>() -> T { todo!() }
-fn main() {
-    let x = make┃();
-}
-```
-
-.After
-```rust
-fn make<T>() -> T { todo!() }
-fn main() {
-    let x = make::<${0:_}>();
-}
-```
-
-
-[discrete]
-=== `apply_demorgan`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/apply_demorgan.rs#L5[apply_demorgan.rs]
-
-Apply [De Morgan's law](https://en.wikipedia.org/wiki/De_Morgan%27s_laws).
-This transforms expressions of the form `!l || !r` into `!(l && r)`.
-This also works with `&&`. This assist can only be applied with the cursor
-on either `||` or `&&`, with both operands being a negation of some kind.
-This means something of the form `!x` or `x != y`.
-
-.Before
-```rust
-fn main() {
-    if x != 4 ||┃ !y {}
-}
-```
-
-.After
-```rust
-fn main() {
-    if !(x == 4 && y) {}
-}
-```
-
-
-[discrete]
-=== `auto_import`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/auto_import.rs#L18[auto_import.rs]
-
-If the name is unresolved, provides all possible imports for it.
-
-.Before
-```rust
-fn main() {
-    let map = HashMap┃::new();
-}
-```
-
-.After
-```rust
-use std::collections::HashMap;
-
-fn main() {
-    let map = HashMap::new();
-}
-```
-
-
-[discrete]
-=== `change_return_type_to_result`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/change_return_type_to_result.rs#L8[change_return_type_to_result.rs]
-
-Change the function's return type to Result.
-
-.Before
-```rust
-fn foo() -> i32┃ { 42i32 }
-```
-
-.After
-```rust
-fn foo() -> Result<i32, ${0:_}> { Ok(42i32) }
-```
-
-
-[discrete]
-=== `change_visibility`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/change_visibility.rs#L14[change_visibility.rs]
-
-Adds or changes existing visibility specifier.
-
-.Before
-```rust
-┃fn frobnicate() {}
-```
-
-.After
-```rust
-pub(crate) fn frobnicate() {}
-```
-
-
-[discrete]
-=== `convert_to_guarded_return`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/early_return.rs#L21[early_return.rs]
-
-Replace a large conditional with a guarded return.
-
-.Before
-```rust
-fn main() {
-    ┃if cond {
-        foo();
-        bar();
-    }
-}
-```
-
-.After
-```rust
-fn main() {
-    if !cond {
-        return;
-    }
-    foo();
-    bar();
-}
-```
-
-
-[discrete]
-=== `fill_match_arms`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/fill_match_arms.rs#L14[fill_match_arms.rs]
-
-Adds missing clauses to a `match` expression.
-
-.Before
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        ┃
-    }
-}
-```
-
-.After
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        $0Action::Move { distance } => {}
-        Action::Stop => {}
-    }
-}
-```
-
-
-[discrete]
-=== `fix_visibility`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/fix_visibility.rs#L13[fix_visibility.rs]
-
-Makes inaccessible item public.
-
-.Before
-```rust
-mod m {
-    fn frobnicate() {}
-}
-fn main() {
-    m::frobnicate┃() {}
-}
-```
-
-.After
-```rust
-mod m {
-    $0pub(crate) fn frobnicate() {}
-}
-fn main() {
-    m::frobnicate() {}
-}
-```
-
-
-[discrete]
-=== `flip_binexpr`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/flip_binexpr.rs#L5[flip_binexpr.rs]
-
-Flips operands of a binary expression.
-
-.Before
-```rust
-fn main() {
-    let _ = 90 +┃ 2;
-}
-```
-
-.After
-```rust
-fn main() {
-    let _ = 2 + 90;
-}
-```
-
-
-[discrete]
-=== `flip_comma`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/flip_comma.rs#L5[flip_comma.rs]
-
-Flips two comma-separated items.
-
-.Before
-```rust
-fn main() {
-    ((1, 2),┃ (3, 4));
-}
-```
-
-.After
-```rust
-fn main() {
-    ((3, 4), (1, 2));
-}
-```
-
-
-[discrete]
-=== `flip_trait_bound`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/flip_trait_bound.rs#L9[flip_trait_bound.rs]
-
-Flips two trait bounds.
-
-.Before
-```rust
-fn foo<T: Clone +┃ Copy>() { }
-```
-
-.After
-```rust
-fn foo<T: Copy + Clone>() { }
-```
-
-
-[discrete]
-=== `inline_local_variable`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/inline_local_variable.rs#L13[inline_local_variable.rs]
-
-Inlines local variable.
-
-.Before
-```rust
-fn main() {
-    let x┃ = 1 + 2;
-    x * 4;
-}
-```
-
-.After
-```rust
-fn main() {
-    (1 + 2) * 4;
-}
-```
-
-
-[discrete]
-=== `introduce_named_lifetime`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/introduce_named_lifetime.rs#L12[introduce_named_lifetime.rs]
-
-Change an anonymous lifetime to a named lifetime.
-
-.Before
-```rust
-impl Cursor<'_┃> {
-    fn node(self) -> &SyntaxNode {
-        match self {
-            Cursor::Replace(node) | Cursor::Before(node) => node,
-        }
-    }
-}
-```
-
-.After
-```rust
-impl<'a> Cursor<'a> {
-    fn node(self) -> &SyntaxNode {
-        match self {
-            Cursor::Replace(node) | Cursor::Before(node) => node,
-        }
-    }
-}
-```
-
-
-[discrete]
-=== `introduce_variable`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/introduce_variable.rs#L14[introduce_variable.rs]
-
-Extracts subexpression into a variable.
-
-.Before
-```rust
-fn main() {
-    ┃(1 + 2)┃ * 4;
-}
-```
-
-.After
-```rust
-fn main() {
-    let $0var_name = (1 + 2);
-    var_name * 4;
-}
-```
-
-
-[discrete]
-=== `invert_if`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/invert_if.rs#L12[invert_if.rs]
-
-Apply invert_if
-This transforms if expressions of the form `if !x {A} else {B}` into `if x {B} else {A}`
-This also works with `!=`. This assist can only be applied with the cursor
-on `if`.
-
-.Before
-```rust
-fn main() {
-    if┃ !y { A } else { B }
-}
-```
-
-.After
-```rust
-fn main() {
-    if y { B } else { A }
-}
-```
-
-
-[discrete]
-=== `make_raw_string`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/raw_string.rs#L10[raw_string.rs]
-
-Adds `r#` to a plain string literal.
-
-.Before
-```rust
-fn main() {
-    "Hello,┃ World!";
-}
-```
-
-.After
-```rust
-fn main() {
-    r#"Hello, World!"#;
-}
-```
-
-
-[discrete]
-=== `make_usual_string`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/raw_string.rs#L39[raw_string.rs]
-
-Turns a raw string into a plain string.
-
-.Before
-```rust
-fn main() {
-    r#"Hello,┃ "World!""#;
-}
-```
-
-.After
-```rust
-fn main() {
-    "Hello, \"World!\"";
-}
-```
-
-
-[discrete]
-=== `merge_imports`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/merge_imports.rs#L14[merge_imports.rs]
-
-Merges two imports with a common prefix.
-
-.Before
-```rust
-use std::┃fmt::Formatter;
-use std::io;
-```
-
-.After
-```rust
-use std::{fmt::Formatter, io};
-```
-
-
-[discrete]
-=== `merge_match_arms`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/merge_match_arms.rs#L11[merge_match_arms.rs]
-
-Merges identical match arms.
-
-.Before
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        ┃Action::Move(..) => foo(),
-        Action::Stop => foo(),
-    }
-}
-```
-
-.After
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move(..) | Action::Stop => foo(),
-    }
-}
-```
-
-
-[discrete]
-=== `move_arm_cond_to_match_guard`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/move_guard.rs#L56[move_guard.rs]
-
-Moves if expression from match arm body into a guard.
-
-.Before
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move { distance } => ┃if distance > 10 { foo() },
-        _ => (),
-    }
-}
-```
-
-.After
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move { distance } if distance > 10 => foo(),
-        _ => (),
-    }
-}
-```
-
-
-[discrete]
-=== `move_bounds_to_where_clause`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/move_bounds.rs#L10[move_bounds.rs]
-
-Moves inline type bounds to a where clause.
-
-.Before
-```rust
-fn apply<T, U, ┃F: FnOnce(T) -> U>(f: F, x: T) -> U {
-    f(x)
-}
-```
-
-.After
-```rust
-fn apply<T, U, F>(f: F, x: T) -> U where F: FnOnce(T) -> U {
-    f(x)
-}
-```
-
-
-[discrete]
-=== `move_guard_to_arm_body`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/move_guard.rs#L8[move_guard.rs]
-
-Moves match guard into match arm body.
-
-.Before
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move { distance } ┃if distance > 10 => foo(),
-        _ => (),
-    }
-}
-```
-
-.After
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move { distance } => if distance > 10 { foo() },
-        _ => (),
-    }
-}
-```
-
-
-[discrete]
-=== `remove_dbg`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/remove_dbg.rs#L8[remove_dbg.rs]
-
-Removes `dbg!()` macro call.
-
-.Before
-```rust
-fn main() {
-    ┃dbg!(92);
-}
-```
-
-.After
-```rust
-fn main() {
-    92;
-}
-```
-
-
-[discrete]
-=== `remove_hash`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/raw_string.rs#L89[raw_string.rs]
-
-Removes a hash from a raw string literal.
-
-.Before
-```rust
-fn main() {
-    r#"Hello,┃ World!"#;
-}
-```
-
-.After
-```rust
-fn main() {
-    r"Hello, World!";
-}
-```
-
-
-[discrete]
-=== `remove_mut`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/remove_mut.rs#L5[remove_mut.rs]
-
-Removes the `mut` keyword.
-
-.Before
-```rust
-impl Walrus {
-    fn feed(&mut┃ self, amount: u32) {}
-}
-```
-
-.After
-```rust
-impl Walrus {
-    fn feed(&self, amount: u32) {}
-}
-```
-
-
-[discrete]
-=== `reorder_fields`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/reorder_fields.rs#L10[reorder_fields.rs]
-
-Reorder the fields of record literals and record patterns in the same order as in
-the definition.
-
-.Before
-```rust
-struct Foo {foo: i32, bar: i32};
-const test: Foo = ┃Foo {bar: 0, foo: 1}
-```
-
-.After
-```rust
-struct Foo {foo: i32, bar: i32};
-const test: Foo = Foo {foo: 1, bar: 0}
-```
-
-
-[discrete]
-=== `replace_if_let_with_match`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/replace_if_let_with_match.rs#L13[replace_if_let_with_match.rs]
-
-Replaces `if let` with an else branch with a `match` expression.
-
-.Before
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    ┃if let Action::Move { distance } = action {
-        foo(distance)
-    } else {
-        bar()
-    }
-}
-```
-
-.After
-```rust
-enum Action { Move { distance: u32 }, Stop }
-
-fn handle(action: Action) {
-    match action {
-        Action::Move { distance } => foo(distance),
-        _ => bar(),
-    }
-}
-```
-
-
-[discrete]
-=== `replace_let_with_if_let`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/replace_let_with_if_let.rs#L14[replace_let_with_if_let.rs]
-
-Replaces `let` with an `if-let`.
-
-.Before
-```rust
-
-fn main(action: Action) {
-    ┃let x = compute();
-}
-
-fn compute() -> Option<i32> { None }
-```
-
-.After
-```rust
-
-fn main(action: Action) {
-    if let Some(x) = compute() {
-    }
-}
-
-fn compute() -> Option<i32> { None }
-```
-
-
-[discrete]
-=== `replace_qualified_name_with_use`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/replace_qualified_name_with_use.rs#L6[replace_qualified_name_with_use.rs]
-
-Adds a use statement for a given fully-qualified name.
-
-.Before
-```rust
-fn process(map: std::collections::┃HashMap<String, String>) {}
-```
-
-.After
-```rust
-use std::collections::HashMap;
-
-fn process(map: HashMap<String, String>) {}
-```
-
-
-[discrete]
-=== `replace_unwrap_with_match`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/replace_unwrap_with_match.rs#L17[replace_unwrap_with_match.rs]
-
-Replaces `unwrap` a `match` expression. Works for Result and Option.
-
-.Before
-```rust
-enum Result<T, E> { Ok(T), Err(E) }
-fn main() {
-    let x: Result<i32, i32> = Result::Ok(92);
-    let y = x.┃unwrap();
-}
-```
-
-.After
-```rust
-enum Result<T, E> { Ok(T), Err(E) }
-fn main() {
-    let x: Result<i32, i32> = Result::Ok(92);
-    let y = match x {
-        Ok(a) => a,
-        $0_ => unreachable!(),
-    };
-}
-```
-
-
-[discrete]
-=== `split_import`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/split_import.rs#L7[split_import.rs]
-
-Wraps the tail of import into braces.
-
-.Before
-```rust
-use std::┃collections::HashMap;
-```
-
-.After
-```rust
-use std::{collections::HashMap};
-```
-
-
-[discrete]
-=== `unwrap_block`
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_assists/src/handlers/unwrap_block.rs#L9[unwrap_block.rs]
-
-This assist removes if...else, for, while and loop control statements to just keep the body.
-
-.Before
-```rust
-fn foo() {
-    if true {┃
-        println!("foo");
-    }
-}
-```
-
-.After
-```rust
-fn foo() {
-    println!("foo");
-}
-```
diff --git a/docs/user/generated_features.adoc b/docs/user/generated_features.adoc
index 56538ca90..23a071cf1 100644
--- a/docs/user/generated_features.adoc
+++ b/docs/user/generated_features.adoc
@@ -76,7 +76,7 @@ Navigates to the type of an identifier.
 
 
 === Hover
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/hover.rs#L63[hover.rs]
+**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/hover.rs#L106[hover.rs]
 
 Shows additional information, like type of an expression or documentation for definition when "focusing" code.
 Focusing is usually hovering with a mouse, but can also be triggered with a shortcut.
@@ -177,7 +177,7 @@ braces, so it won't confuse generics with comparisons.
 
 
 === On Typing Assists
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/typing.rs#L35[typing.rs]
+**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/typing.rs#L37[typing.rs]
 
 Some features trigger on typing certain characters:
 
@@ -199,7 +199,7 @@ Navigates to the parent module of the current module.
 
 
 === Run
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/runnables.rs#L45[runnables.rs]
+**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/runnables.rs#L81[runnables.rs]
 
 Shows a popup suggesting to run a test/benchmark/binary **at the current cursor
 location**. Super useful for repeatedly running just a single test. Do bind this
@@ -213,7 +213,7 @@ to a shortcut!
 
 
 === Semantic Syntax Highlighting
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/syntax_highlighting.rs#L33[syntax_highlighting.rs]
+**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide/src/syntax_highlighting.rs#L34[syntax_highlighting.rs]
 
 rust-analyzer highlights the code semantically.
 For example, `bar` in `foo::Bar` might be colored differently depending on whether `Bar` is an enum or a trait.
@@ -275,7 +275,7 @@ String::from((y + 5).foo(z))
 
 
 === Workspace Symbol
-**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide_db/src/symbol_index.rs#L113[symbol_index.rs]
+**Source:** https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/ra_ide_db/src/symbol_index.rs#L122[symbol_index.rs]
 
 Uses fuzzy-search to find types, modules and functions by name across your
 project and dependencies. This is **the** most useful feature, which improves code
diff --git a/docs/user/manual.adoc b/docs/user/manual.adoc
index 202783fd9..ea714f49a 100644
--- a/docs/user/manual.adoc
+++ b/docs/user/manual.adoc
@@ -269,6 +269,57 @@ Gnome Builder currently has support for RLS, and there's no way to configure the
 1. Rename, symlink or copy the `rust-analyzer` binary to `rls` and place it somewhere Builder can find (in `PATH`, or under `~/.cargo/bin`).
 2. Enable the Rust Builder plugin.
 
+== Non-Cargo Based Projects
+
+rust-analyzer does not require Cargo.
+However, if you use some other build system, you'll have to describe the structure of your project for rust-analyzer in the `rust-project.json` format:
+
+[source,TypeScript]
+----
+interface JsonProject {
+   /// The set of paths containing the crates for this project.
+   /// Any `Crate` must be nested inside some `root`.
+   roots: string[];
+   /// The set of crates comprising the current project.
+   /// Must include all transitive dependencies as well as sysroot crate (libstd, libcore and such).
+   crates: Crate[];
+}
+
+interface Crate {
+    /// Path to the root module of the crate.
+    root_module: string;
+    /// Edition of the crate.
+    edition: "2015" | "2018";
+    /// Dependencies
+    deps: Dep[];
+    /// The set of cfgs activated for a given crate, like `["unix", "feature=foo", "feature=bar"]`.
+    cfg: string[];
+
+    /// value of the OUT_DIR env variable.
+    out_dir?: string;
+    /// For proc-macro crates, path to compiles proc-macro (.so file).
+    proc_macro_dylib_path?: string;
+}
+
+interface Dep {
+    /// Index of a crate in the `crates` array.
+    crate: number,
+    /// Name as should appear in the (implicit) `extern crate name` declaration.
+    name: string,
+}
+----
+
+This format is provisional and subject to change.
+Specifically, the `roots` setup will be different eventually.
+
+There are tree ways to feed `rust-project.json` to rust-analyzer:
+
+* Place `rust-project.json` file at the root of the project, and rust-anlayzer will discover it.
+* Specify `"rust-analyzer.linkedProjects": [ "path/to/rust-project.json" ]` in the settings (and make sure that your LSP client sends settings as a part of initialize request).
+* Specify `"rust-analyzer.linkedProjects": [ { "roots": [...], "crates": [...] }]` inline.
+
+See https://github.com/rust-analyzer/rust-project.json-example for a small example.
+
 == Features
 
 include::./generated_features.adoc[]
diff --git a/editors/code/package.json b/editors/code/package.json
index 75dbafc05..e2027970d 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -238,7 +238,7 @@
                 },
                 "rust-analyzer.cargo.allFeatures": {
                     "type": "boolean",
-                    "default": true,
+                    "default": false,
                     "description": "Activate all available features"
                 },
                 "rust-analyzer.cargo.features": {
@@ -318,9 +318,23 @@
                     "markdownDescription": "Check all targets and tests (will be passed as `--all-targets`)"
                 },
                 "rust-analyzer.checkOnSave.allFeatures": {
-                    "type": "boolean",
-                    "default": true,
-                    "markdownDescription": "Check with all features (will be passed as `--all-features`)"
+                    "type": [
+                        "null",
+                        "boolean"
+                    ],
+                    "default": null,
+                    "markdownDescription": "Check with all features (will be passed as `--all-features`). Defaults to `rust-analyzer.cargo.allFeatures`."
+                },
+                "rust-analyzer.checkOnSave.features": {
+                    "type": [
+                        "null",
+                        "array"
+                    ],
+                    "items": {
+                        "type": "string"
+                    },
+                    "default": null,
+                    "description": "List of features to activate. Defaults to `rust-analyzer.cargo.features`."
                 },
                 "rust-analyzer.inlayHints.enable": {
                     "type": "boolean",
@@ -462,17 +476,53 @@
                     "default": true
                 },
                 "rust-analyzer.lens.run": {
-                    "markdownDescription": "Whether to show Run lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
+                    "markdownDescription": "Whether to show `Run` lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
                     "type": "boolean",
                     "default": true
                 },
                 "rust-analyzer.lens.debug": {
-                    "markdownDescription": "Whether to show Debug lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
+                    "markdownDescription": "Whether to show `Debug` lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
                     "type": "boolean",
                     "default": true
                 },
                 "rust-analyzer.lens.implementations": {
-                    "markdownDescription": "Whether to show Implementations lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
+                    "markdownDescription": "Whether to show `Implementations` lens. Only applies when `#rust-analyzer.lens.enable#` is set.",
+                    "type": "boolean",
+                    "default": true
+                },
+                "rust-analyzer.hoverActions.enable": {
+                    "description": "Whether to show HoverActions in Rust files.",
+                    "type": "boolean",
+                    "default": true
+                },
+                "rust-analyzer.hoverActions.implementations": {
+                    "markdownDescription": "Whether to show `Implementations` action. Only applies when `#rust-analyzer.hoverActions.enable#` is set.",
+                    "type": "boolean",
+                    "default": true
+                },
+                "rust-analyzer.hoverActions.run": {
+                    "markdownDescription": "Whether to show `Run` action. Only applies when `#rust-analyzer.hoverActions.enable#` is set.",
+                    "type": "boolean",
+                    "default": true
+                },
+                "rust-analyzer.hoverActions.debug": {
+                    "markdownDescription": "Whether to show `Debug` action. Only applies when `#rust-analyzer.hoverActions.enable#` is set.",
+                    "type": "boolean",
+                    "default": true
+                },
+                "rust-analyzer.linkedProjects": {
+                    "markdownDescription": "Disable project auto-discovery in favor of explicitly specified set of projects.  \nElements must be paths pointing to Cargo.toml, rust-project.json, or JSON objects in rust-project.json format",
+                    "type": "array",
+                    "items": {
+                        "type": [
+                            "string",
+                            "object"
+                        ]
+                    },
+                    "default": null
+                },
+                "rust-analyzer.withSysroot": {
+                    "markdownDescription": "Internal config for debugging, disables loading of sysroot crates",
                     "type": "boolean",
                     "default": true
                 }
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index d64f9a3f9..65ad573d8 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -1,8 +1,25 @@
 import * as lc from 'vscode-languageclient';
 import * as vscode from 'vscode';
+import * as ra from '../src/lsp_ext';
+import * as Is from 'vscode-languageclient/lib/utils/is';
 
 import { CallHierarchyFeature } from 'vscode-languageclient/lib/callHierarchy.proposed';
 import { SemanticTokensFeature, DocumentSemanticsTokensSignature } from 'vscode-languageclient/lib/semanticTokens.proposed';
+import { assert } from './util';
+
+function renderCommand(cmd: ra.CommandLink) {
+    return `[${cmd.title}](command:${cmd.command}?${encodeURIComponent(JSON.stringify(cmd.arguments))} '${cmd.tooltip!}')`;
+}
+
+function renderHoverActions(actions: ra.CommandLinkGroup[]): vscode.MarkdownString {
+    const text = actions.map(group =>
+        (group.title ? (group.title + " ") : "") + group.commands.map(renderCommand).join(' | ')
+    ).join('___');
+
+    const result = new vscode.MarkdownString(text);
+    result.isTrusted = true;
+    return result;
+}
 
 export function createClient(serverPath: string, cwd: string): lc.LanguageClient {
     // '.' Is the fallback if no folder is open
@@ -32,6 +49,25 @@ export function createClient(serverPath: string, cwd: string): lc.LanguageClient
                 if (res === undefined) throw new Error('busy');
                 return res;
             },
+            async provideHover(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken, _next: lc.ProvideHoverSignature) {
+                return client.sendRequest(lc.HoverRequest.type, client.code2ProtocolConverter.asTextDocumentPositionParams(document, position), token).then(
+                    (result) => {
+                        const hover = client.protocol2CodeConverter.asHover(result);
+                        if (hover) {
+                            const actions = (<any>result).actions;
+                            if (actions) {
+                                hover.contents.push(renderHoverActions(actions));
+                            }
+                        }
+                        return hover;
+                    },
+                    (error) => {
+                        client.logFailedRequest(lc.HoverRequest.type, error);
+                        return Promise.resolve(null);
+                    });
+            },
+            // Using custom handling of CodeActions where each code action is resloved lazily
+            // That's why we are not waiting for any command or edits
             async provideCodeActions(document: vscode.TextDocument, range: vscode.Range, context: vscode.CodeActionContext, token: vscode.CancellationToken, _next: lc.ProvideCodeActionsSignature) {
                 const params: lc.CodeActionParams = {
                     textDocument: client.code2ProtocolConverter.asTextDocumentIdentifier(document),
@@ -43,32 +79,36 @@ export function createClient(serverPath: string, cwd: string): lc.LanguageClient
                     const result: (vscode.CodeAction | vscode.Command)[] = [];
                     const groups = new Map<string, { index: number; items: vscode.CodeAction[] }>();
                     for (const item of values) {
+                        // In our case we expect to get code edits only from diagnostics
                         if (lc.CodeAction.is(item)) {
+                            assert(!item.command, "We don't expect to receive commands in CodeActions");
                             const action = client.protocol2CodeConverter.asCodeAction(item);
-                            const group = actionGroup(item);
-                            if (isSnippetEdit(item) || group) {
-                                action.command = {
-                                    command: "rust-analyzer.applySnippetWorkspaceEdit",
-                                    title: "",
-                                    arguments: [action.edit],
-                                };
-                                action.edit = undefined;
-                            }
-
-                            if (group) {
-                                let entry = groups.get(group);
-                                if (!entry) {
-                                    entry = { index: result.length, items: [] };
-                                    groups.set(group, entry);
-                                    result.push(action);
-                                }
-                                entry.items.push(action);
-                            } else {
+                            result.push(action);
+                            continue;
+                        }
+                        assert(isCodeActionWithoutEditsAndCommands(item), "We don't expect edits or commands here");
+                        const action = new vscode.CodeAction(item.title);
+                        const group = (item as any).group;
+                        const id = (item as any).id;
+                        const resolveParams: ra.ResolveCodeActionParams = {
+                            id: id,
+                            codeActionParams: params
+                        };
+                        action.command = {
+                            command: "rust-analyzer.resolveCodeAction",
+                            title: item.title,
+                            arguments: [resolveParams],
+                        };
+                        if (group) {
+                            let entry = groups.get(group);
+                            if (!entry) {
+                                entry = { index: result.length, items: [] };
+                                groups.set(group, entry);
                                 result.push(action);
                             }
+                            entry.items.push(action);
                         } else {
-                            const command = client.protocol2CodeConverter.asCommand(item);
-                            result.push(command);
+                            result.push(action);
                         }
                     }
                     for (const [group, { index, items }] of groups) {
@@ -80,7 +120,7 @@ export function createClient(serverPath: string, cwd: string): lc.LanguageClient
                                 command: "rust-analyzer.applyActionGroup",
                                 title: "",
                                 arguments: [items.map((item) => {
-                                    return { label: item.title, edit: item.command!!.arguments!![0] };
+                                    return { label: item.title, arguments: item.command!!.arguments!![0] };
                                 })],
                             };
                             result[index] = action;
@@ -119,24 +159,18 @@ class ExperimentalFeatures implements lc.StaticFeature {
         const caps: any = capabilities.experimental ?? {};
         caps.snippetTextEdit = true;
         caps.codeActionGroup = true;
+        caps.resolveCodeAction = true;
+        caps.hoverActions = true;
         capabilities.experimental = caps;
     }
     initialize(_capabilities: lc.ServerCapabilities<any>, _documentSelector: lc.DocumentSelector | undefined): void {
     }
 }
 
-function isSnippetEdit(action: lc.CodeAction): boolean {
-    const documentChanges = action.edit?.documentChanges ?? [];
-    for (const edit of documentChanges) {
-        if (lc.TextDocumentEdit.is(edit)) {
-            if (edit.edits.some((indel) => (indel as any).insertTextFormat === lc.InsertTextFormat.Snippet)) {
-                return true;
-            }
-        }
-    }
-    return false;
-}
-
-function actionGroup(action: lc.CodeAction): string | undefined {
-    return (action as any).group;
+function isCodeActionWithoutEditsAndCommands(value: any): boolean {
+    const candidate: lc.CodeAction = value;
+    return candidate && Is.string(candidate.title) &&
+        (candidate.diagnostics === void 0 || Is.typedArray(candidate.diagnostics, lc.Diagnostic.is)) &&
+        (candidate.kind === void 0 || Is.string(candidate.kind)) &&
+        (candidate.edit === void 0 && candidate.command === void 0);
 }
diff --git a/editors/code/src/commands.ts b/editors/code/src/commands.ts
index 86302db37..3e9c3aa0e 100644
--- a/editors/code/src/commands.ts
+++ b/editors/code/src/commands.ts
@@ -8,6 +8,7 @@ import { spawnSync } from 'child_process';
 import { RunnableQuickPick, selectRunnable, createTask } from './run';
 import { AstInspector } from './ast_inspector';
 import { isRustDocument, sleep, isRustEditor } from './util';
+import { startDebugSession, makeDebugConfig } from './debug';
 
 export * from './ast_inspector';
 export * from './run';
@@ -197,20 +198,6 @@ export function toggleInlayHints(ctx: Ctx): Cmd {
     };
 }
 
-export function run(ctx: Ctx): Cmd {
-    let prevRunnable: RunnableQuickPick | undefined;
-
-    return async () => {
-        const item = await selectRunnable(ctx, prevRunnable);
-        if (!item) return;
-
-        item.detail = 'rerun';
-        prevRunnable = item;
-        const task = createTask(item.runnable);
-        return await vscode.tasks.executeTask(task);
-    };
-}
-
 // Opens the virtual file that will show the syntax tree
 //
 // The contents of the file come from the `TextDocumentContentProvider`
@@ -356,10 +343,25 @@ export function showReferences(ctx: Ctx): Cmd {
 }
 
 export function applyActionGroup(_ctx: Ctx): Cmd {
-    return async (actions: { label: string; edit: vscode.WorkspaceEdit }[]) => {
+    return async (actions: { label: string; arguments: ra.ResolveCodeActionParams }[]) => {
         const selectedAction = await vscode.window.showQuickPick(actions);
         if (!selectedAction) return;
-        await applySnippetWorkspaceEdit(selectedAction.edit);
+        vscode.commands.executeCommand(
+            'rust-analyzer.resolveCodeAction',
+            selectedAction.arguments,
+        );
+    };
+}
+
+export function resolveCodeAction(ctx: Ctx): Cmd {
+    const client = ctx.client;
+    return async (params: ra.ResolveCodeActionParams) => {
+        const item: lc.WorkspaceEdit = await client.sendRequest(ra.resolveCodeAction, params);
+        if (!item) {
+            return;
+        }
+        const edit = client.protocol2CodeConverter.asWorkspaceEdit(item);
+        await applySnippetWorkspaceEdit(edit);
     };
 }
 
@@ -368,3 +370,62 @@ export function applySnippetWorkspaceEditCommand(_ctx: Ctx): Cmd {
         await applySnippetWorkspaceEdit(edit);
     };
 }
+
+export function run(ctx: Ctx): Cmd {
+    let prevRunnable: RunnableQuickPick | undefined;
+
+    return async () => {
+        const item = await selectRunnable(ctx, prevRunnable);
+        if (!item) return;
+
+        item.detail = 'rerun';
+        prevRunnable = item;
+        const task = createTask(item.runnable);
+        return await vscode.tasks.executeTask(task);
+    };
+}
+
+export function runSingle(ctx: Ctx): Cmd {
+    return async (runnable: ra.Runnable) => {
+        const editor = ctx.activeRustEditor;
+        if (!editor) return;
+
+        const task = createTask(runnable);
+        task.group = vscode.TaskGroup.Build;
+        task.presentationOptions = {
+            reveal: vscode.TaskRevealKind.Always,
+            panel: vscode.TaskPanelKind.Dedicated,
+            clear: true,
+        };
+
+        return vscode.tasks.executeTask(task);
+    };
+}
+
+export function debug(ctx: Ctx): Cmd {
+    let prevDebuggee: RunnableQuickPick | undefined;
+
+    return async () => {
+        const item = await selectRunnable(ctx, prevDebuggee, true);
+        if (!item) return;
+
+        item.detail = 'restart';
+        prevDebuggee = item;
+        return await startDebugSession(ctx, item.runnable);
+    };
+}
+
+export function debugSingle(ctx: Ctx): Cmd {
+    return async (config: ra.Runnable) => {
+        await startDebugSession(ctx, config);
+    };
+}
+
+export function newDebugConfig(ctx: Ctx): Cmd {
+    return async () => {
+        const item = await selectRunnable(ctx, undefined, true, false);
+        if (!item) return;
+
+        await makeDebugConfig(ctx, item.runnable);
+    };
+}
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index e8abf8284..d8f0037d4 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -16,10 +16,8 @@ export class Config {
         "files",
         "highlighting",
         "updates.channel",
-        "lens.enable",
-        "lens.run",
-        "lens.debug",
-        "lens.implementations",
+        "lens", // works as lens.*
+        "hoverActions", // works as hoverActions.*
     ]
         .map(opt => `${this.rootSection}.${opt}`);
 
@@ -132,4 +130,11 @@ export class Config {
             implementations: this.get<boolean>("lens.implementations"),
         };
     }
+
+    get hoverActions() {
+        return {
+            enable: this.get<boolean>("hoverActions.enable"),
+            implementations: this.get<boolean>("hoverActions.implementations"),
+        };
+    }
 }
diff --git a/editors/code/src/debug.ts b/editors/code/src/debug.ts
index 027504ecd..a0c9b3ab2 100644
--- a/editors/code/src/debug.ts
+++ b/editors/code/src/debug.ts
@@ -3,46 +3,59 @@ import * as vscode from 'vscode';
 import * as path from 'path';
 import * as ra from './lsp_ext';
 
-import { Cargo } from './cargo';
+import { Cargo } from './toolchain';
 import { Ctx } from "./ctx";
 
 const debugOutput = vscode.window.createOutputChannel("Debug");
 type DebugConfigProvider = (config: ra.Runnable, executable: string, sourceFileMap?: Record<string, string>) => vscode.DebugConfiguration;
 
-function getLldbDebugConfig(config: ra.Runnable, executable: string, sourceFileMap?: Record<string, string>): vscode.DebugConfiguration {
-    return {
-        type: "lldb",
-        request: "launch",
-        name: config.label,
-        program: executable,
-        args: config.extraArgs,
-        cwd: config.cwd,
-        sourceMap: sourceFileMap,
-        sourceLanguages: ["rust"]
-    };
-}
+export async function makeDebugConfig(ctx: Ctx, runnable: ra.Runnable): Promise<void> {
+    const scope = ctx.activeRustEditor?.document.uri;
+    if (!scope) return;
 
-function getCppvsDebugConfig(config: ra.Runnable, executable: string, sourceFileMap?: Record<string, string>): vscode.DebugConfiguration {
-    return {
-        type: (os.platform() === "win32") ? "cppvsdbg" : "cppdbg",
-        request: "launch",
-        name: config.label,
-        program: executable,
-        args: config.extraArgs,
-        cwd: config.cwd,
-        sourceFileMap: sourceFileMap,
-    };
+    const debugConfig = await getDebugConfiguration(ctx, runnable);
+    if (!debugConfig) return;
+
+    const wsLaunchSection = vscode.workspace.getConfiguration("launch", scope);
+    const configurations = wsLaunchSection.get<any[]>("configurations") || [];
+
+    const index = configurations.findIndex(c => c.name === debugConfig.name);
+    if (index !== -1) {
+        const answer = await vscode.window.showErrorMessage(`Launch configuration '${debugConfig.name}' already exists!`, 'Cancel', 'Update');
+        if (answer === "Cancel") return;
+
+        configurations[index] = debugConfig;
+    } else {
+        configurations.push(debugConfig);
+    }
+
+    await wsLaunchSection.update("configurations", configurations);
 }
 
-async function getDebugExecutable(config: ra.Runnable): Promise<string> {
-    const cargo = new Cargo(config.cwd || '.', debugOutput);
-    const executable = await cargo.executableFromArgs(config.args);
+export async function startDebugSession(ctx: Ctx, runnable: ra.Runnable): Promise<boolean> {
+    let debugConfig: vscode.DebugConfiguration | undefined = undefined;
+    let message = "";
 
-    // if we are here, there were no compilation errors.
-    return executable;
+    const wsLaunchSection = vscode.workspace.getConfiguration("launch");
+    const configurations = wsLaunchSection.get<any[]>("configurations") || [];
+
+    const index = configurations.findIndex(c => c.name === runnable.label);
+    if (-1 !== index) {
+        debugConfig = configurations[index];
+        message = " (from launch.json)";
+        debugOutput.clear();
+    } else {
+        debugConfig = await getDebugConfiguration(ctx, runnable);
+    }
+
+    if (!debugConfig) return false;
+
+    debugOutput.appendLine(`Launching debug configuration${message}:`);
+    debugOutput.appendLine(JSON.stringify(debugConfig, null, 2));
+    return vscode.debug.startDebugging(undefined, debugConfig);
 }
 
-export async function getDebugConfiguration(ctx: Ctx, config: ra.Runnable): Promise<vscode.DebugConfiguration | undefined> {
+async function getDebugConfiguration(ctx: Ctx, runnable: ra.Runnable): Promise<vscode.DebugConfiguration | undefined> {
     const editor = ctx.activeRustEditor;
     if (!editor) return;
 
@@ -78,8 +91,8 @@ export async function getDebugConfiguration(ctx: Ctx, config: ra.Runnable): Prom
         return path.normalize(p).replace(wsFolder, '${workspaceRoot}');
     }
 
-    const executable = await getDebugExecutable(config);
-    const debugConfig = knownEngines[debugEngine.id](config, simplifyPath(executable), debugOptions.sourceFileMap);
+    const executable = await getDebugExecutable(runnable);
+    const debugConfig = knownEngines[debugEngine.id](runnable, simplifyPath(executable), debugOptions.sourceFileMap);
     if (debugConfig.type in debugOptions.engineSettings) {
         const settingsMap = (debugOptions.engineSettings as any)[debugConfig.type];
         for (var key in settingsMap) {
@@ -100,25 +113,35 @@ export async function getDebugConfiguration(ctx: Ctx, config: ra.Runnable): Prom
     return debugConfig;
 }
 
-export async function startDebugSession(ctx: Ctx, config: ra.Runnable): Promise<boolean> {
-    let debugConfig: vscode.DebugConfiguration | undefined = undefined;
-    let message = "";
-
-    const wsLaunchSection = vscode.workspace.getConfiguration("launch");
-    const configurations = wsLaunchSection.get<any[]>("configurations") || [];
+async function getDebugExecutable(runnable: ra.Runnable): Promise<string> {
+    const cargo = new Cargo(runnable.args.workspaceRoot || '.', debugOutput);
+    const executable = await cargo.executableFromArgs(runnable.args.cargoArgs);
 
-    const index = configurations.findIndex(c => c.name === config.label);
-    if (-1 !== index) {
-        debugConfig = configurations[index];
-        message = " (from launch.json)";
-        debugOutput.clear();
-    } else {
-        debugConfig = await getDebugConfiguration(ctx, config);
-    }
+    // if we are here, there were no compilation errors.
+    return executable;
+}
 
-    if (!debugConfig) return false;
+function getLldbDebugConfig(runnable: ra.Runnable, executable: string, sourceFileMap?: Record<string, string>): vscode.DebugConfiguration {
+    return {
+        type: "lldb",
+        request: "launch",
+        name: runnable.label,
+        program: executable,
+        args: runnable.args.executableArgs,
+        cwd: runnable.args.workspaceRoot,
+        sourceMap: sourceFileMap,
+        sourceLanguages: ["rust"]
+    };
+}
 
-    debugOutput.appendLine(`Launching debug configuration${message}:`);
-    debugOutput.appendLine(JSON.stringify(debugConfig, null, 2));
-    return vscode.debug.startDebugging(undefined, debugConfig);
+function getCppvsDebugConfig(runnable: ra.Runnable, executable: string, sourceFileMap?: Record<string, string>): vscode.DebugConfiguration {
+    return {
+        type: (os.platform() === "win32") ? "cppvsdbg" : "cppdbg",
+        request: "launch",
+        name: runnable.label,
+        program: executable,
+        args: runnable.args.executableArgs,
+        cwd: runnable.args.workspaceRoot,
+        sourceFileMap: sourceFileMap,
+    };
 }
diff --git a/editors/code/src/lsp_ext.ts b/editors/code/src/lsp_ext.ts
index 4da12eb30..e16ea799c 100644
--- a/editors/code/src/lsp_ext.ts
+++ b/editors/code/src/lsp_ext.ts
@@ -33,6 +33,12 @@ export const matchingBrace = new lc.RequestType<MatchingBraceParams, lc.Position
 
 export const parentModule = new lc.RequestType<lc.TextDocumentPositionParams, lc.LocationLink[], void>("experimental/parentModule");
 
+export interface ResolveCodeActionParams {
+    id: string;
+    codeActionParams: lc.CodeActionParams;
+}
+export const resolveCodeAction = new lc.RequestType<ResolveCodeActionParams, lc.WorkspaceEdit, unknown>('experimental/resolveCodeAction');
+
 export interface JoinLinesParams {
     textDocument: lc.TextDocumentIdentifier;
     ranges: lc.Range[];
@@ -45,16 +51,18 @@ export interface RunnablesParams {
     textDocument: lc.TextDocumentIdentifier;
     position: lc.Position | null;
 }
+
 export interface Runnable {
-    range: lc.Range;
     label: string;
-    bin: string;
-    args: string[];
-    extraArgs: string[];
-    env: { [key: string]: string };
-    cwd: string | null;
+    location?: lc.LocationLink;
+    kind: "cargo";
+    args: {
+        workspaceRoot?: string;
+        cargoArgs: string[];
+        executableArgs: string[];
+    };
 }
-export const runnables = new lc.RequestType<RunnablesParams, Runnable[], void>("rust-analyzer/runnables");
+export const runnables = new lc.RequestType<RunnablesParams, Runnable[], void>("experimental/runnables");
 
 export type InlayHint = InlayHint.TypeHint | InlayHint.ParamHint | InlayHint.ChainingHint;
 
@@ -82,3 +90,15 @@ export interface SsrParams {
     parseOnly: boolean;
 }
 export const ssr = new lc.RequestType<SsrParams, lc.WorkspaceEdit, void>('experimental/ssr');
+
+export interface CommandLink extends lc.Command {
+    /**
+     * A tooltip for the command, when represented in the UI.
+     */
+    tooltip?: string;
+}
+
+export interface CommandLinkGroup {
+    title?: string;
+    commands: CommandLink[];
+}
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index b7337621c..a92c676fa 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -98,6 +98,7 @@ export async function activate(context: vscode.ExtensionContext) {
     ctx.registerCommand('debugSingle', commands.debugSingle);
     ctx.registerCommand('showReferences', commands.showReferences);
     ctx.registerCommand('applySnippetWorkspaceEdit', commands.applySnippetWorkspaceEditCommand);
+    ctx.registerCommand('resolveCodeAction', commands.resolveCodeAction);
     ctx.registerCommand('applyActionGroup', commands.applyActionGroup);
 
     ctx.pushCleanup(activateTaskProvider(workspaceFolder));
diff --git a/editors/code/src/run.ts b/editors/code/src/run.ts
index 8e1ba83ed..bb060cfe1 100644
--- a/editors/code/src/run.ts
+++ b/editors/code/src/run.ts
@@ -1,9 +1,10 @@
 import * as vscode from 'vscode';
 import * as lc from 'vscode-languageclient';
 import * as ra from './lsp_ext';
+import * as toolchain from "./toolchain";
 
-import { Ctx, Cmd } from './ctx';
-import { startDebugSession, getDebugConfiguration } from './debug';
+import { Ctx } from './ctx';
+import { makeDebugConfig } from './debug';
 
 const quickPickButtons = [{ iconPath: new vscode.ThemeIcon("save"), tooltip: "Save as a launch.json configurtation." }];
 
@@ -64,7 +65,7 @@ export async function selectRunnable(ctx: Ctx, prevRunnable?: RunnableQuickPick,
             quickPick.onDidHide(() => close()),
             quickPick.onDidAccept(() => close(quickPick.selectedItems[0])),
             quickPick.onDidTriggerButton((_button) => {
-                (async () => await makeDebugConfig(ctx, quickPick.activeItems[0]))();
+                (async () => await makeDebugConfig(ctx, quickPick.activeItems[0].runnable))();
                 close();
             }),
             quickPick.onDidChangeActive((active) => {
@@ -83,74 +84,6 @@ export async function selectRunnable(ctx: Ctx, prevRunnable?: RunnableQuickPick,
     });
 }
 
-export function runSingle(ctx: Ctx): Cmd {
-    return async (runnable: ra.Runnable) => {
-        const editor = ctx.activeRustEditor;
-        if (!editor) return;
-
-        const task = createTask(runnable);
-        task.group = vscode.TaskGroup.Build;
-        task.presentationOptions = {
-            reveal: vscode.TaskRevealKind.Always,
-            panel: vscode.TaskPanelKind.Dedicated,
-            clear: true,
-        };
-
-        return vscode.tasks.executeTask(task);
-    };
-}
-
-export function debug(ctx: Ctx): Cmd {
-    let prevDebuggee: RunnableQuickPick | undefined;
-
-    return async () => {
-        const item = await selectRunnable(ctx, prevDebuggee, true);
-        if (!item) return;
-
-        item.detail = 'restart';
-        prevDebuggee = item;
-        return await startDebugSession(ctx, item.runnable);
-    };
-}
-
-export function debugSingle(ctx: Ctx): Cmd {
-    return async (config: ra.Runnable) => {
-        await startDebugSession(ctx, config);
-    };
-}
-
-async function makeDebugConfig(ctx: Ctx, item: RunnableQuickPick): Promise<void> {
-    const scope = ctx.activeRustEditor?.document.uri;
-    if (!scope) return;
-
-    const debugConfig = await getDebugConfiguration(ctx, item.runnable);
-    if (!debugConfig) return;
-
-    const wsLaunchSection = vscode.workspace.getConfiguration("launch", scope);
-    const configurations = wsLaunchSection.get<any[]>("configurations") || [];
-
-    const index = configurations.findIndex(c => c.name === debugConfig.name);
-    if (index !== -1) {
-        const answer = await vscode.window.showErrorMessage(`Launch configuration '${debugConfig.name}' already exists!`, 'Cancel', 'Update');
-        if (answer === "Cancel") return;
-
-        configurations[index] = debugConfig;
-    } else {
-        configurations.push(debugConfig);
-    }
-
-    await wsLaunchSection.update("configurations", configurations);
-}
-
-export function newDebugConfig(ctx: Ctx): Cmd {
-    return async () => {
-        const item = await selectRunnable(ctx, undefined, true, false);
-        if (!item) return;
-
-        await makeDebugConfig(ctx, item);
-    };
-}
-
 export class RunnableQuickPick implements vscode.QuickPickItem {
     public label: string;
     public description?: string | undefined;
@@ -170,18 +103,27 @@ interface CargoTaskDefinition extends vscode.TaskDefinition {
     env?: { [key: string]: string };
 }
 
-export function createTask(spec: ra.Runnable): vscode.Task {
+export function createTask(runnable: ra.Runnable): vscode.Task {
     const TASK_SOURCE = 'Rust';
+
+    let command;
+    switch (runnable.kind) {
+        case "cargo": command = toolchain.getPathForExecutable("cargo");
+    }
+    const args = [...runnable.args.cargoArgs]; // should be a copy!
+    if (runnable.args.executableArgs.length > 0) {
+        args.push('--', ...runnable.args.executableArgs);
+    }
     const definition: CargoTaskDefinition = {
         type: 'cargo',
-        label: spec.label,
-        command: spec.bin,
-        args: spec.extraArgs ? [...spec.args, '--', ...spec.extraArgs] : spec.args,
-        env: Object.assign({}, process.env, spec.env),
+        label: runnable.label,
+        command,
+        args,
+        env: Object.assign({}, process.env as { [key: string]: string }, { "RUST_BACKTRACE": "short" }),
     };
 
     const execOption: vscode.ShellExecutionOptions = {
-        cwd: spec.cwd || '.',
+        cwd: runnable.args.workspaceRoot || '.',
         env: definition.env,
     };
     const exec = new vscode.ShellExecution(
diff --git a/editors/code/src/tasks.ts b/editors/code/src/tasks.ts
index 1366c76d6..9748824df 100644
--- a/editors/code/src/tasks.ts
+++ b/editors/code/src/tasks.ts
@@ -1,4 +1,5 @@
 import * as vscode from 'vscode';
+import * as toolchain from "./toolchain";
 
 // This ends up as the `type` key in tasks.json. RLS also uses `cargo` and
 // our configuration should be compatible with it so use the same key.
@@ -24,6 +25,8 @@ class CargoTaskProvider implements vscode.TaskProvider {
         // set of tasks that always exist. These tasks cannot be removed in
         // tasks.json - only tweaked.
 
+        const cargoPath = toolchain.cargoPath();
+
         return [
             { command: 'build', group: vscode.TaskGroup.Build },
             { command: 'check', group: vscode.TaskGroup.Build },
@@ -46,7 +49,7 @@ class CargoTaskProvider implements vscode.TaskProvider {
                     `cargo ${command}`,
                     'rust',
                     // What to do when this command is executed.
-                    new vscode.ShellExecution('cargo', [command]),
+                    new vscode.ShellExecution(cargoPath, [command]),
                     // Problem matchers.
                     ['$rustc'],
                 );
@@ -80,4 +83,4 @@ class CargoTaskProvider implements vscode.TaskProvider {
 export function activateTaskProvider(target: vscode.WorkspaceFolder): vscode.Disposable {
     const provider = new CargoTaskProvider(target);
     return vscode.tasks.registerTaskProvider(TASK_TYPE, provider);
-}
\ No newline at end of file
+}
diff --git a/editors/code/src/cargo.ts b/editors/code/src/toolchain.ts
index a55b2f860..80a7915e9 100644
--- a/editors/code/src/cargo.ts
+++ b/editors/code/src/toolchain.ts
@@ -1,9 +1,10 @@
 import * as cp from 'child_process';
 import * as os from 'os';
 import * as path from 'path';
+import * as fs from 'fs';
 import * as readline from 'readline';
 import { OutputChannel } from 'vscode';
-import { isValidExecutable } from './util';
+import { log, memoize } from './util';
 
 interface CompilationArtifact {
     fileName: string;
@@ -17,33 +18,34 @@ export interface ArtifactSpec {
     filter?: (artifacts: CompilationArtifact[]) => CompilationArtifact[];
 }
 
-export function artifactSpec(args: readonly string[]): ArtifactSpec {
-    const cargoArgs = [...args, "--message-format=json"];
+export class Cargo {
+    constructor(readonly rootFolder: string, readonly output: OutputChannel) { }
 
-    // arguments for a runnable from the quick pick should be updated.
-    // see crates\rust-analyzer\src\main_loop\handlers.rs, handle_code_lens
-    switch (cargoArgs[0]) {
-        case "run": cargoArgs[0] = "build"; break;
-        case "test": {
-            if (!cargoArgs.includes("--no-run")) {
-                cargoArgs.push("--no-run");
+    // Made public for testing purposes
+    static artifactSpec(args: readonly string[]): ArtifactSpec {
+        const cargoArgs = [...args, "--message-format=json"];
+
+        // arguments for a runnable from the quick pick should be updated.
+        // see crates\rust-analyzer\src\main_loop\handlers.rs, handle_code_lens
+        switch (cargoArgs[0]) {
+            case "run": cargoArgs[0] = "build"; break;
+            case "test": {
+                if (!cargoArgs.includes("--no-run")) {
+                    cargoArgs.push("--no-run");
+                }
+                break;
             }
-            break;
         }
-    }
 
-    const result: ArtifactSpec = { cargoArgs: cargoArgs };
-    if (cargoArgs[0] === "test") {
-        // for instance, `crates\rust-analyzer\tests\heavy_tests\main.rs` tests
-        // produce 2 artifacts: {"kind": "bin"} and {"kind": "test"}
-        result.filter = (artifacts) => artifacts.filter(it => it.isTest);
-    }
-
-    return result;
-}
+        const result: ArtifactSpec = { cargoArgs: cargoArgs };
+        if (cargoArgs[0] === "test") {
+            // for instance, `crates\rust-analyzer\tests\heavy_tests\main.rs` tests
+            // produce 2 artifacts: {"kind": "bin"} and {"kind": "test"}
+            result.filter = (artifacts) => artifacts.filter(it => it.isTest);
+        }
 
-export class Cargo {
-    constructor(readonly rootFolder: string, readonly output: OutputChannel) { }
+        return result;
+    }
 
     private async getArtifacts(spec: ArtifactSpec): Promise<CompilationArtifact[]> {
         const artifacts: CompilationArtifact[] = [];
@@ -77,7 +79,7 @@ export class Cargo {
     }
 
     async executableFromArgs(args: readonly string[]): Promise<string> {
-        const artifacts = await this.getArtifacts(artifactSpec(args));
+        const artifacts = await this.getArtifacts(Cargo.artifactSpec(args));
 
         if (artifacts.length === 0) {
             throw new Error('No compilation artifacts');
@@ -94,14 +96,7 @@ export class Cargo {
         onStderrString: (data: string) => void
     ): Promise<number> {
         return new Promise((resolve, reject) => {
-            let cargoPath;
-            try {
-                cargoPath = getCargoPathOrFail();
-            } catch (err) {
-                return reject(err);
-            }
-
-            const cargo = cp.spawn(cargoPath, cargoArgs, {
+            const cargo = cp.spawn(cargoPath(), cargoArgs, {
                 stdio: ['ignore', 'pipe', 'pipe'],
                 cwd: this.rootFolder
             });
@@ -126,26 +121,54 @@ export class Cargo {
     }
 }
 
-// Mirrors `ra_env::get_path_for_executable` implementation
-function getCargoPathOrFail(): string {
-    const envVar = process.env.CARGO;
-    const executableName = "cargo";
+/** Mirrors `ra_toolchain::cargo()` implementation */
+export function cargoPath(): string {
+    return getPathForExecutable("cargo");
+}
+
+/** Mirrors `ra_toolchain::get_path_for_executable()` implementation */
+export const getPathForExecutable = memoize(
+    // We apply caching to decrease file-system interactions
+    (executableName: "cargo" | "rustc" | "rustup"): string => {
+        {
+            const envVar = process.env[executableName.toUpperCase()];
+            if (envVar) return envVar;
+        }
+
+        if (lookupInPath(executableName)) return executableName;
 
-    if (envVar) {
-        if (isValidExecutable(envVar)) return envVar;
+        try {
+            // hmm, `os.homedir()` seems to be infallible
+            // it is not mentioned in docs and cannot be infered by the type signature...
+            const standardPath = path.join(os.homedir(), ".cargo", "bin", executableName);
 
-        throw new Error(`\`${envVar}\` environment variable points to something that's not a valid executable`);
+            if (isFile(standardPath)) return standardPath;
+        } catch (err) {
+            log.error("Failed to read the fs info", err);
+        }
+        return executableName;
     }
+);
 
-    if (isValidExecutable(executableName)) return executableName;
+function lookupInPath(exec: string): boolean {
+    const paths = process.env.PATH ?? "";;
 
-    const standardLocation = path.join(os.homedir(), '.cargo', 'bin', executableName);
+    const candidates = paths.split(path.delimiter).flatMap(dirInPath => {
+        const candidate = path.join(dirInPath, exec);
+        return os.type() === "Windows_NT"
+            ? [candidate, `${candidate}.exe`]
+            : [candidate];
+    });
 
-    if (isValidExecutable(standardLocation)) return standardLocation;
+    return candidates.some(isFile);
+}
 
-    throw new Error(
-        `Failed to find \`${executableName}\` executable. ` +
-        `Make sure \`${executableName}\` is in \`$PATH\`, ` +
-        `or set \`${envVar}\` to point to a valid executable.`
-    );
+function isFile(suspectPath: string): boolean {
+    // It is not mentionned in docs, but `statSync()` throws an error when
+    // the path doesn't exist
+    try {
+        return fs.statSync(suspectPath).isFile();
+    } catch {
+        return false;
+    }
 }
diff --git a/editors/code/src/util.ts b/editors/code/src/util.ts
index 352ef9162..fe3fb71cd 100644
--- a/editors/code/src/util.ts
+++ b/editors/code/src/util.ts
@@ -99,3 +99,21 @@ export function isValidExecutable(path: string): boolean {
 export function setContextValue(key: string, value: any): Thenable<void> {
     return vscode.commands.executeCommand('setContext', key, value);
 }
+
+/**
+ * Returns a higher-order function that caches the results of invoking the
+ * underlying function.
+ */
+export function memoize<Ret, TThis, Param extends string>(func: (this: TThis, arg: Param) => Ret) {
+    const cache = new Map<string, Ret>();
+
+    return function(this: TThis, arg: Param) {
+        const cached = cache.get(arg);
+        if (cached) return cached;
+
+        const result = func.call(this, arg);
+        cache.set(arg, result);
+
+        return result;
+    };
+}
diff --git a/editors/code/tests/unit/launch_config.test.ts b/editors/code/tests/unit/launch_config.test.ts
index d5cf1b74e..68794d53e 100644
--- a/editors/code/tests/unit/launch_config.test.ts
+++ b/editors/code/tests/unit/launch_config.test.ts
@@ -1,25 +1,25 @@
 import * as assert from 'assert';
-import * as cargo from '../../src/cargo';
+import { Cargo } from '../../src/toolchain';
 
 suite('Launch configuration', () => {
 
     suite('Lens', () => {
         test('A binary', async () => {
-            const args = cargo.artifactSpec(["build", "--package", "pkg_name", "--bin", "pkg_name"]);
+            const args = Cargo.artifactSpec(["build", "--package", "pkg_name", "--bin", "pkg_name"]);
 
             assert.deepEqual(args.cargoArgs, ["build", "--package", "pkg_name", "--bin", "pkg_name", "--message-format=json"]);
             assert.deepEqual(args.filter, undefined);
         });
 
         test('One of Multiple Binaries', async () => {
-            const args = cargo.artifactSpec(["build", "--package", "pkg_name", "--bin", "bin1"]);
+            const args = Cargo.artifactSpec(["build", "--package", "pkg_name", "--bin", "bin1"]);
 
             assert.deepEqual(args.cargoArgs, ["build", "--package", "pkg_name", "--bin", "bin1", "--message-format=json"]);
             assert.deepEqual(args.filter, undefined);
         });
 
         test('A test', async () => {
-            const args = cargo.artifactSpec(["test", "--package", "pkg_name", "--lib", "--no-run"]);
+            const args = Cargo.artifactSpec(["test", "--package", "pkg_name", "--lib", "--no-run"]);
 
             assert.deepEqual(args.cargoArgs, ["test", "--package", "pkg_name", "--lib", "--no-run", "--message-format=json"]);
             assert.notDeepEqual(args.filter, undefined);
@@ -28,7 +28,7 @@ suite('Launch configuration', () => {
 
     suite('QuickPick', () => {
         test('A binary', async () => {
-            const args = cargo.artifactSpec(["run", "--package", "pkg_name", "--bin", "pkg_name"]);
+            const args = Cargo.artifactSpec(["run", "--package", "pkg_name", "--bin", "pkg_name"]);
 
             assert.deepEqual(args.cargoArgs, ["build", "--package", "pkg_name", "--bin", "pkg_name", "--message-format=json"]);
             assert.deepEqual(args.filter, undefined);
@@ -36,14 +36,14 @@ suite('Launch configuration', () => {
 
 
         test('One of Multiple Binaries', async () => {
-            const args = cargo.artifactSpec(["run", "--package", "pkg_name", "--bin", "bin2"]);
+            const args = Cargo.artifactSpec(["run", "--package", "pkg_name", "--bin", "bin2"]);
 
             assert.deepEqual(args.cargoArgs, ["build", "--package", "pkg_name", "--bin", "bin2", "--message-format=json"]);
             assert.deepEqual(args.filter, undefined);
         });
 
         test('A test', async () => {
-            const args = cargo.artifactSpec(["test", "--package", "pkg_name", "--lib"]);
+            const args = Cargo.artifactSpec(["test", "--package", "pkg_name", "--lib"]);
 
             assert.deepEqual(args.cargoArgs, ["test", "--package", "pkg_name", "--lib", "--message-format=json", "--no-run"]);
             assert.notDeepEqual(args.filter, undefined);
diff --git a/xtask/src/ast_src.rs b/xtask/src/ast_src.rs
index f60f0fb16..392648d71 100644
--- a/xtask/src/ast_src.rs
+++ b/xtask/src/ast_src.rs
@@ -1707,7 +1707,7 @@ pub(crate) const AST_SRC: AstSrc = AstSrc {
         /// ```
         ///
         /// [Reference](https://doc.rust-lang.org/reference/items/generics.html#where-clauses)
-        struct WherePred: TypeBoundsOwner { T![lifetime], TypeRef }
+        struct WherePred: TypeBoundsOwner { T![for], TypeParamList, T![lifetime], TypeRef }
 
         /// Where clause.
         ///
diff --git a/xtask/src/codegen.rs b/xtask/src/codegen.rs
index 5511c01d5..f5f4b964a 100644
--- a/xtask/src/codegen.rs
+++ b/xtask/src/codegen.rs
@@ -18,8 +18,10 @@ use std::{
 use crate::{not_bash::fs2, project_root, Result};
 
 pub use self::{
-    gen_assists_docs::generate_assists_docs, gen_feature_docs::generate_feature_docs,
-    gen_parser_tests::generate_parser_tests, gen_syntax::generate_syntax,
+    gen_assists_docs::{generate_assists_docs, generate_assists_tests},
+    gen_feature_docs::generate_feature_docs,
+    gen_parser_tests::generate_parser_tests,
+    gen_syntax::generate_syntax,
 };
 
 const GRAMMAR_DIR: &str = "crates/ra_parser/src/grammar";
diff --git a/xtask/src/codegen/gen_assists_docs.rs b/xtask/src/codegen/gen_assists_docs.rs
index 6c1be5350..526941f73 100644
--- a/xtask/src/codegen/gen_assists_docs.rs
+++ b/xtask/src/codegen/gen_assists_docs.rs
@@ -7,16 +7,17 @@ use crate::{
     project_root, rust_files, Result,
 };
 
-pub fn generate_assists_docs(mode: Mode) -> Result<()> {
+pub fn generate_assists_tests(mode: Mode) -> Result<()> {
     let assists = Assist::collect()?;
-    generate_tests(&assists, mode)?;
+    generate_tests(&assists, mode)
+}
 
+pub fn generate_assists_docs(mode: Mode) -> Result<()> {
+    let assists = Assist::collect()?;
     let contents = assists.into_iter().map(|it| it.to_string()).collect::<Vec<_>>().join("\n\n");
     let contents = contents.trim().to_string() + "\n";
     let dst = project_root().join("docs/user/generated_assists.adoc");
-    codegen::update(&dst, &contents, mode)?;
-
-    Ok(())
+    codegen::update(&dst, &contents, mode)
 }
 
 #[derive(Debug)]
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index 19d5594f5..745a25862 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -40,7 +40,7 @@ fn generate_tokens(grammar: AstSrc<'_>) -> Result<String> {
                 pub(crate) syntax: SyntaxToken,
             }
             impl std::fmt::Display for #name {
-                fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                     std::fmt::Display::fmt(&self.syntax, f)
                 }
             }
@@ -68,7 +68,7 @@ fn generate_nodes(kinds: KindsSrc<'_>, grammar: AstSrc<'_>) -> Result<String> {
         .iter()
         .map(|node| {
             let name = format_ident!("{}", node.name);
-            let kind = format_ident!("{}", to_upper_snake_case(&name.to_string()));
+            let kind = format_ident!("{}", to_upper_snake_case(node.name));
             let traits = node.traits.iter().map(|trait_name| {
                 let trait_name = format_ident!("{}", trait_name);
                 quote!(impl ast::#trait_name for #name {})
@@ -199,7 +199,7 @@ fn generate_nodes(kinds: KindsSrc<'_>, grammar: AstSrc<'_>) -> Result<String> {
         enum_names.chain(node_names.clone()).map(|it| format_ident!("{}", it)).map(|name| {
             quote! {
                 impl std::fmt::Display for #name {
-                    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                         std::fmt::Display::fmt(self.syntax(), f)
                     }
                 }
diff --git a/xtask/src/lib.rs b/xtask/src/lib.rs
index 874957885..747654c1f 100644
--- a/xtask/src/lib.rs
+++ b/xtask/src/lib.rs
@@ -4,6 +4,7 @@
 
 pub mod not_bash;
 pub mod install;
+pub mod release;
 pub mod dist;
 pub mod pre_commit;
 
@@ -19,7 +20,7 @@ use walkdir::{DirEntry, WalkDir};
 
 use crate::{
     codegen::Mode,
-    not_bash::{date_iso, fs2, pushd, pushenv, rm_rf, run},
+    not_bash::{fs2, pushd, pushenv, rm_rf, run},
 };
 
 pub use anyhow::{bail, Context as _, Result};
@@ -153,58 +154,6 @@ pub fn run_pre_cache() -> Result<()> {
     Ok(())
 }
 
-pub fn run_release(dry_run: bool) -> Result<()> {
-    if !dry_run {
-        run!("git switch release")?;
-        run!("git fetch upstream --tags --force")?;
-        run!("git reset --hard tags/nightly")?;
-        run!("git push")?;
-    }
-
-    let website_root = project_root().join("../rust-analyzer.github.io");
-    let changelog_dir = website_root.join("./thisweek/_posts");
-
-    let today = date_iso()?;
-    let commit = run!("git rev-parse HEAD")?;
-    let changelog_n = fs2::read_dir(changelog_dir.as_path())?.count();
-
-    let contents = format!(
-        "\
-= Changelog #{}
-:sectanchors:
-:page-layout: post
-
-Commit: commit:{}[] +
-Release: release:{}[]
-
-== New Features
-
-* pr:[] .
-
-== Fixes
-
-== Internal Improvements
-",
-        changelog_n, commit, today
-    );
-
-    let path = changelog_dir.join(format!("{}-changelog-{}.adoc", today, changelog_n));
-    fs2::write(&path, &contents)?;
-
-    for &adoc in ["manual.adoc", "generated_features.adoc", "generated_assists.adoc"].iter() {
-        let src = project_root().join("./docs/user/").join(adoc);
-        let dst = website_root.join(adoc);
-        fs2::copy(src, dst)?;
-    }
-
-    let tags = run!("git tag --list"; echo = false)?;
-    let prev_tag = tags.lines().filter(|line| is_release_tag(line)).last().unwrap();
-
-    println!("\n    git log {}..HEAD --merges --reverse", prev_tag);
-
-    Ok(())
-}
-
 fn is_release_tag(tag: &str) -> bool {
     tag.len() == "2020-02-24".len() && tag.starts_with(|c: char| c.is_ascii_digit())
 }
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index 9d7cdd114..f7a79362d 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -16,8 +16,9 @@ use xtask::{
     dist::run_dist,
     install::{ClientOpt, InstallCmd, ServerOpt},
     not_bash::pushd,
-    pre_commit, project_root, run_clippy, run_fuzzer, run_pre_cache, run_release, run_rustfmt,
-    Result,
+    pre_commit, project_root,
+    release::ReleaseCmd,
+    run_clippy, run_fuzzer, run_pre_cache, run_rustfmt, Result,
 };
 
 fn main() -> Result<()> {
@@ -74,6 +75,7 @@ FLAGS:
             args.finish()?;
             codegen::generate_syntax(Mode::Overwrite)?;
             codegen::generate_parser_tests(Mode::Overwrite)?;
+            codegen::generate_assists_tests(Mode::Overwrite)?;
             codegen::generate_assists_docs(Mode::Overwrite)?;
             codegen::generate_feature_docs(Mode::Overwrite)?;
             Ok(())
@@ -101,7 +103,7 @@ FLAGS:
         "release" => {
             let dry_run = args.contains("--dry-run");
             args.finish()?;
-            run_release(dry_run)
+            ReleaseCmd { dry_run }.run()
         }
         "dist" => {
             let nightly = args.contains("--nightly");
diff --git a/xtask/src/release.rs b/xtask/src/release.rs
new file mode 100644
index 000000000..36c912184
--- /dev/null
+++ b/xtask/src/release.rs
@@ -0,0 +1,67 @@
+use crate::{
+    codegen, is_release_tag,
+    not_bash::{date_iso, fs2, run},
+    project_root, Mode, Result,
+};
+
+pub struct ReleaseCmd {
+    pub dry_run: bool,
+}
+
+impl ReleaseCmd {
+    pub fn run(self) -> Result<()> {
+        if !self.dry_run {
+            run!("git switch release")?;
+            run!("git fetch upstream --tags --force")?;
+            run!("git reset --hard tags/nightly")?;
+            run!("git push")?;
+        }
+        codegen::generate_assists_docs(Mode::Overwrite)?;
+        codegen::generate_feature_docs(Mode::Overwrite)?;
+
+        let website_root = project_root().join("../rust-analyzer.github.io");
+        let changelog_dir = website_root.join("./thisweek/_posts");
+
+        let today = date_iso()?;
+        let commit = run!("git rev-parse HEAD")?;
+        let changelog_n = fs2::read_dir(changelog_dir.as_path())?.count();
+
+        let contents = format!(
+            "\
+    = Changelog #{}
+    :sectanchors:
+    :page-layout: post
+
+    Commit: commit:{}[] +
+    Release: release:{}[]
+
+    == New Features
+
+    * pr:[] .
+
+    == Fixes
+
+    == Internal Improvements
+    ",
+            changelog_n, commit, today
+        );
+
+        let path = changelog_dir.join(format!("{}-changelog-{}.adoc", today, changelog_n));
+        fs2::write(&path, &contents)?;
+
+        for &adoc in ["manual.adoc", "generated_features.adoc", "generated_assists.adoc"].iter() {
+            let src = project_root().join("./docs/user/").join(adoc);
+            let dst = website_root.join(adoc);
+            fs2::copy(src, dst)?;
+        }
+
+        let tags = run!("git tag --list"; echo = false)?;
+        let prev_tag = tags.lines().filter(|line| is_release_tag(line)).last().unwrap();
+
+        let git_log = run!("git log {}..HEAD --merges --reverse", prev_tag; echo = false)?;
+        let git_log_dst = website_root.join("git.log");
+        fs2::write(git_log_dst, &git_log)?;
+
+        Ok(())
+    }
+}
diff --git a/xtask/tests/tidy.rs b/xtask/tests/tidy.rs
index 4ac5d929f..d38ac7f17 100644
--- a/xtask/tests/tidy.rs
+++ b/xtask/tests/tidy.rs
@@ -25,19 +25,12 @@ fn generated_tests_are_fresh() {
 
 #[test]
 fn generated_assists_are_fresh() {
-    if let Err(error) = codegen::generate_assists_docs(Mode::Verify) {
+    if let Err(error) = codegen::generate_assists_tests(Mode::Verify) {
         panic!("{}. Please update assists by running `cargo xtask codegen`", error);
     }
 }
 
 #[test]
-fn generated_features_are_fresh() {
-    if let Err(error) = codegen::generate_feature_docs(Mode::Verify) {
-        panic!("{}. Please update features by running `cargo xtask codegen`", error);
-    }
-}
-
-#[test]
 fn check_code_formatting() {
     if let Err(error) = run_rustfmt(Mode::Verify) {
         panic!("{}. Please format the code by running `cargo format`", error);
@@ -180,13 +173,11 @@ impl TidyDocs {
 }
 
 fn is_exclude_dir(p: &Path, dirs_to_exclude: &[&str]) -> bool {
-    let mut cur_path = p;
-    while let Some(path) = cur_path.parent() {
-        if dirs_to_exclude.iter().any(|dir| path.ends_with(dir)) {
-            return true;
-        }
-        cur_path = path;
-    }
-
-    false
+    p.strip_prefix(project_root())
+        .unwrap()
+        .components()
+        .rev()
+        .skip(1)
+        .filter_map(|it| it.as_os_str().to_str())
+        .any(|it| dirs_to_exclude.contains(&it))
 }