28 files changed, 668 insertions, 474 deletions
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 395ce1ef4..77c92512a 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -1,4 +1,4 @@
-name: CI-Release
+name: release
 on:
  push:
    branches:
@@ -132,7 +132,9 @@ jobs:
      - name: Create Release
        id: create_release
-        uses: actions/create-release@v1
+        # uses: actions/create-release@v1
+        # https://github.com/actions/create-release/pull/32
+        uses: fleskesvor/create-release@1a72e235c178bf2ae6c51a8ae36febc24568c5fe
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
diff --git a/Cargo.lock b/Cargo.lock
index 01e86ab0e..8c88f46ed 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,7 +2,7 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.7.6"
+version = "0.7.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "memchr 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -45,7 +45,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "backtrace"
-version = "0.3.42"
+version = "0.3.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -300,7 +300,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "dtoa"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -419,7 +419,7 @@ name = "globset"
 version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "aho-corasick 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)",
 "bstr 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -614,7 +614,7 @@ dependencies = [
 [[package]]
 name = "lsp-types"
-version = "0.70.0"
+version = "0.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -755,7 +755,7 @@ dependencies = [
 "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -895,7 +895,7 @@ dependencies = [
 "insta 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "jod-thread 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "lsp-types 0.70.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lsp-types 0.70.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1061,7 +1061,7 @@ dependencies = [
 "jod-thread 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "lsp-server 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "lsp-types 0.70.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lsp-types 0.70.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_cargo_watch 0.1.0",
 "ra_ide 0.1.0",
@@ -1090,7 +1090,7 @@ dependencies = [
 "ra_syntax 0.1.0",
 "ra_tt 0.1.0",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 ]
@@ -1105,7 +1105,7 @@ dependencies = [
 name = "ra_prof"
 version = "0.1.0"
 dependencies = [
- "backtrace 0.3.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.43 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "jemalloc-ctl 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "jemallocator 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1365,7 +1365,7 @@ name = "regex"
 version = "1.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "aho-corasick 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)",
 "memchr 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "regex-syntax 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
 "thread_local 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1446,7 +1446,7 @@ dependencies = [
 "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "salsa-macros 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1530,7 +1530,7 @@ name = "serde_yaml"
 version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "dtoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dtoa 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
 "yaml-rust 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1543,7 +1543,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "smallvec"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -1646,7 +1646,7 @@ name = "unicode-normalization"
 version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "smallvec 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1756,14 +1756,14 @@ dependencies = [
 ]
 [metadata]
-"checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
+"checksum aho-corasick 0.7.7 (registry+https://github.com/rust-lang/crates.io-index)" = "5f56c476256dc249def911d6f7580b5fc7e875895b5d7ee88f5d602208035744"
 "checksum anyhow 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)" = "7825f6833612eb2414095684fcf6c635becf3ce97fe48cf6421321e93bfbd53c"
 "checksum anymap 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "33954243bd79057c2de7338850b85983a44588021f8a5fee574a8888c6de4344"
 "checksum arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
 "checksum atty 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
 "checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
 "checksum autocfg 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f8aac770f1885fd7e387acedd76065302551364496e46b3dd00860b2f8359b9d"
-"checksum backtrace 0.3.42 (registry+https://github.com/rust-lang/crates.io-index)" = "b4b1549d804b6c73f4817df2ba073709e96e426f12987127c48e6745568c350b"
+"checksum backtrace 0.3.43 (registry+https://github.com/rust-lang/crates.io-index)" = "7f80256bc78f67e7df7e36d77366f636ed976895d91fe2ab9efa3973e8fe8c4f"
 "checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
 "checksum base64 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b41b7ea54a0c9d92199de89e20e58d49f02f8e699814ef3fdf266f6f748d15c7"
 "checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
@@ -1792,7 +1792,7 @@ dependencies = [
 "checksum crossbeam-utils 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ce446db02cdc3165b94ae73111e570793400d0794e46125cc4056c81cbb039f4"
 "checksum difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "524cbf6897b527295dff137cec09ecf3a05f4fddffd7dfcd1585403449e74198"
 "checksum drop_bomb 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "69b26e475fd29098530e709294e94e661974c851aed42512793f120fed4e199f"
-"checksum dtoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ea57b42383d091c85abcc2706240b94ab2a8fa1fc81c10ff23c4de06e2a90b5e"
+"checksum dtoa 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "4358a9e11b9a09cf52383b451b49a169e8d797b68aa02301ff586d70d9661ea3"
 "checksum either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bb1f6b1ce1c140482ea30ddd3335fc0024ac7ee112895426e0a629a6c20adfe3"
 "checksum ena 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8944dc8fa28ce4a38f778bd46bf7d923fe73eed5a439398507246c8e017e6f36"
 "checksum encode_unicode 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
@@ -1834,7 +1834,7 @@ dependencies = [
 "checksum lock_api 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "79b2de95ecb4691949fea4716ca53cdbcfccb2c612e19644a8bad05edcf9f47b"
 "checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
 "checksum lsp-server 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5383e043329615624bbf45e1ba27bd75c176762b2592855c659bc28ac580a06b"
-"checksum lsp-types 0.70.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef197b24cb3f12fc3984667a505691fec9d683204ddff56f12b2d1940e09a988"
+"checksum lsp-types 0.70.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d267f222864db3db63cf7e18493a2a5c84edab1f4e3c7211c9390ce033365210"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memchr 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3197e20c7edb283f87c071ddfc7a2cca8f8e0b888c242959846a6fce03c72223"
 "checksum memoffset 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "75189eb85871ea5c2e2c15abbdd541185f63b408415e5051f5cac122d8c774b9"
@@ -1902,7 +1902,7 @@ dependencies = [
 "checksum serde_repr 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "cd02c7587ec314570041b2754829f84d873ced14a96d1fd1823531e11db40573"
 "checksum serde_yaml 0.8.11 (registry+https://github.com/rust-lang/crates.io-index)" = "691b17f19fc1ec9d94ec0b5864859290dff279dbd7b03f017afda54eb36c3c35"
 "checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
-"checksum smallvec 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "44e59e0c9fa00817912ae6e4e6e3c4fe04455e75699d06eedc7d85917ed8e8f4"
+"checksum smallvec 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5c2fb2ec9bcd216a5b0d0ccf31ab17b5ed1d627960edff65bbe95d3ce221cefc"
 "checksum smol_str 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)" = "34836c9a295c62c2ce3514471117c5cb269891e8421b2aafdd910050576c4d8b"
 "checksum superslice 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ab16ced94dbd8a46c82fd81e3ed9a8727dac2977ea869d217bcc4ea1f122e81f"
 "checksum syn 1.0.14 (registry+https://github.com/rust-lang/crates.io-index)" = "af6f3550d8dff9ef7dc34d384ac6f107e5d31c8f57d9f28e0081503f547ac8f5"
diff --git a/README.md b/README.md
index 4a76ea6e3..2f6ed1e05 100644
--- a/README.md
+++ b/README.md
@@ -4,10 +4,9 @@
 Rust Analyzer is an **experimental** modular compiler frontend for the Rust
 language. It is a part of a larger rls-2.0 effort to create excellent IDE
-support for Rust. If you want to get involved, check the rls-2.0 working group
+support for Rust. If you want to get involved, check the rls-2.0 working group:
-in the compiler-team repository:
-https://github.com/rust-lang/compiler-team/tree/master/content/working-groups/rls-2.0
+https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
 Work on the Rust Analyzer is sponsored by
diff --git a/crates/ra_assists/src/assists/auto_import.rs b/crates/ra_assists/src/assists/auto_import.rs
index 9163cc662..69126a1c9 100644
--- a/crates/ra_assists/src/assists/auto_import.rs
+++ b/crates/ra_assists/src/assists/auto_import.rs
@@ -1,8 +1,8 @@
 use hir::db::HirDatabase;
 use ra_syntax::{
    ast::{self, AstNode},
-    SmolStr, SyntaxElement,
+    SmolStr,
-    SyntaxKind::{NAME_REF, USE_ITEM},
+    SyntaxKind::USE_ITEM,
    SyntaxNode,
 };
@@ -32,25 +32,28 @@ pub(crate) fn auto_import<F: ImportsLocator>(
    ctx: AssistCtx<impl HirDatabase>,
    imports_locator: &mut F,
 ) -> Option<Assist> {
-    let path: ast::Path = ctx.find_node_at_offset()?;
+    let path_to_import: ast::Path = ctx.find_node_at_offset()?;
-    let module = path.syntax().ancestors().find_map(ast::Module::cast);
+    let path_to_import_syntax = path_to_import.syntax();
+    if path_to_import_syntax.ancestors().find(|ancestor| ancestor.kind() == USE_ITEM).is_some() {
+        return None;
+    }
+    let module = path_to_import_syntax.ancestors().find_map(ast::Module::cast);
    let position = match module.and_then(|it| it.item_list()) {
        Some(item_list) => item_list.syntax().clone(),
        None => {
-            let current_file = path.syntax().ancestors().find_map(ast::SourceFile::cast)?;
+            let current_file = path_to_import_syntax.ancestors().find_map(ast::SourceFile::cast)?;
            current_file.syntax().clone()
        }
    };
    let source_analyzer = ctx.source_analyzer(&position, None);
    let module_with_name_to_import = source_analyzer.module()?;
-    let path_to_import = ctx.covering_element().ancestors().find_map(ast::Path::cast)?;
    if source_analyzer.resolve_path(ctx.db, &path_to_import).is_some() {
        return None;
    }
-    let name_to_import = &find_applicable_name_ref(ctx.covering_element())?.syntax().to_string();
    let proposed_imports = imports_locator
-        .find_imports(&name_to_import.to_string())
+        .find_imports(&path_to_import_syntax.to_string())
        .into_iter()
        .filter_map(|module_def| module_with_name_to_import.find_use_path(ctx.db, module_def))
        .filter(|use_path| !use_path.segments.is_empty())
@@ -64,26 +67,11 @@ pub(crate) fn auto_import<F: ImportsLocator>(
    ctx.add_assist_group(AssistId("auto_import"), "auto import", || {
        proposed_imports
            .into_iter()
-            .map(|import| import_to_action(import, &position, &path_to_import.syntax()))
+            .map(|import| import_to_action(import, &position, &path_to_import_syntax))
            .collect()
    })
 }
-fn find_applicable_name_ref(element: SyntaxElement) -> Option<ast::NameRef> {
-    if element.ancestors().find(|ancestor| ancestor.kind() == USE_ITEM).is_some() {
-        None
-    } else if element.kind() == NAME_REF {
-        Some(element.as_node().cloned().and_then(ast::NameRef::cast)?)
-    } else {
-        let parent = element.parent()?;
-        if parent.kind() == NAME_REF {
-            Some(ast::NameRef::cast(parent)?)
-        } else {
-            None
-        }
-    }
-}
 fn import_to_action(import: String, position: &SyntaxNode, anchor: &SyntaxNode) -> ActionBuilder {
    let mut action_builder = ActionBuilder::default();
    action_builder.label(format!("Import `{}`", &import));
@@ -110,16 +98,16 @@ mod tests {
            auto_import,
            TestImportsLocator::new,
            r"
-            PubStruct<|>
+            <|>PubStruct
            pub mod PubMod {
                pub struct PubStruct;
            }
            ",
            r"
-            use PubMod::PubStruct;
+            <|>use PubMod::PubStruct;
-            PubStruct<|>
+            PubStruct
            pub mod PubMod {
                pub struct PubStruct;
@@ -134,7 +122,7 @@ mod tests {
            auto_import,
            TestImportsLocator::new,
            r"
-            PubStruct<|>
+            PubSt<|>ruct
            pub mod PubMod1 {
                pub struct PubStruct;
@@ -149,7 +137,7 @@ mod tests {
            r"
            use PubMod1::PubStruct;
-            PubStruct<|>
+            PubSt<|>ruct
            pub mod PubMod1 {
                pub struct PubStruct;
diff --git a/crates/ra_cargo_watch/Cargo.toml b/crates/ra_cargo_watch/Cargo.toml
index 49e06e0d3..dd814fc9d 100644
--- a/crates/ra_cargo_watch/Cargo.toml
+++ b/crates/ra_cargo_watch/Cargo.toml
@@ -11,6 +11,7 @@ log = "0.4.3"
 cargo_metadata = "0.9.1"
 jod-thread = "0.1.0"
 parking_lot = "0.10.0"
+serde_json = "1.0.45"
 [dev-dependencies]
 insta = "0.13.0"
diff --git a/crates/ra_cargo_watch/src/lib.rs b/crates/ra_cargo_watch/src/lib.rs
index e7b700c10..ea7ddc86b 100644
--- a/crates/ra_cargo_watch/src/lib.rs
+++ b/crates/ra_cargo_watch/src/lib.rs
@@ -9,7 +9,7 @@ use lsp_types::{
 };
 use std::{
    collections::HashMap,
-    io::BufReader,
+    io::{BufRead, BufReader},
    path::PathBuf,
    process::{Command, Stdio},
    sync::Arc,
@@ -216,8 +216,10 @@ impl CheckWatcherThread {
                self.last_update_req.take();
                task_send.send(CheckTask::ClearDiagnostics).unwrap();
-                // By replacing the watcher, we drop the previous one which
+                // Replace with a dummy watcher first so we drop the original and wait for completion
-                // causes it to shut down automatically.
+                std::mem::replace(&mut self.watcher, WatchThread::dummy());
+                // Then create the actual new watcher
                self.watcher = WatchThread::new(&self.options, &self.workspace_root);
            }
        }
@@ -348,17 +350,45 @@ impl WatchThread {
            // which will break out of the loop, and continue the shutdown
            let _ = message_send.send(CheckEvent::Begin);
-            for message in
+            // We manually read a line at a time, instead of using serde's
-                cargo_metadata::parse_messages(BufReader::new(command.stdout.take().unwrap()))
+            // stream deserializers, because the deserializer cannot recover
-            {
+            // from an error, resulting in it getting stuck, because we try to
+            // be resillient against failures.
+            //
+            // Because cargo only outputs one JSON object per line, we can
+            // simply skip a line if it doesn't parse, which just ignores any
+            // erroneus output.
+            let stdout = BufReader::new(command.stdout.take().unwrap());
+            for line in stdout.lines() {
+                let line = match line {
+                    Ok(line) => line,
+                    Err(err) => {
+                        log::error!("Couldn't read line from cargo: {}", err);
+                        continue;
+                    }
+                };
+                let message = serde_json::from_str::<cargo_metadata::Message>(&line);
                let message = match message {
                    Ok(message) => message,
                    Err(err) => {
-                        log::error!("Invalid json from cargo check, ignoring: {}", err);
+                        log::error!(
+                            "Invalid json from cargo check, ignoring ({}): {:?} ",
+                            err,
+                            line
+                        );
                        continue;
                    }
                };
+                // Skip certain kinds of messages to only spend time on what's useful
+                match &message {
+                    Message::CompilerArtifact(artifact) if artifact.fresh => continue,
+                    Message::BuildScriptExecuted(_) => continue,
+                    Message::Unknown => continue,
+                    _ => {}
+                }
                match message_send.send(CheckEvent::Msg(message)) {
                    Ok(()) => {}
                    Err(_err) => {
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index e6079b88d..a77bf6de6 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,20 +1,24 @@
 //! FIXME: write short doc here
 pub use hir_def::db::{
-    BodyQuery, BodyWithSourceMapQuery, ComputeCrateDefMapQuery, ConstDataQuery,
+    AttrsQuery, BodyQuery, BodyWithSourceMapQuery, ComputeCrateDefMapQuery, ConstDataQuery,
    CrateLangItemsQuery, DefDatabase, DefDatabaseStorage, DocumentationQuery, EnumDataQuery,
-    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternDatabase,
+    ExprScopesQuery, FunctionDataQuery, GenericParamsQuery, ImplDataQuery, InternConstQuery,
-    InternDatabaseStorage, LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery,
+    InternDatabase, InternDatabaseStorage, InternEnumQuery, InternFunctionQuery, InternImplQuery,
-    StructDataQuery, TraitDataQuery, TypeAliasDataQuery,
+    InternStaticQuery, InternStructQuery, InternTraitQuery, InternTypeAliasQuery, InternUnionQuery,
+    LangItemQuery, ModuleLangItemsQuery, RawItemsQuery, StaticDataQuery, StructDataQuery,
+    TraitDataQuery, TypeAliasDataQuery, UnionDataQuery,
 };
 pub use hir_expand::db::{
-    AstDatabase, AstDatabaseStorage, AstIdMapQuery, MacroArgQuery, MacroDefQuery, MacroExpandQuery,
+    AstDatabase, AstDatabaseStorage, AstIdMapQuery, InternMacroQuery, MacroArgQuery, MacroDefQuery,
-    ParseMacroQuery,
+    MacroExpandQuery, ParseMacroQuery,
 };
 pub use hir_ty::db::{
-    AssociatedTyDataQuery, CallableItemSignatureQuery, DoInferQuery, FieldTypesQuery,
+    AssociatedTyDataQuery, AssociatedTyValueQuery, CallableItemSignatureQuery, DoInferQuery,
-    GenericDefaultsQuery, GenericPredicatesQuery, HirDatabase, HirDatabaseStorage, ImplDatumQuery,
+    FieldTypesQuery, GenericDefaultsQuery, GenericPredicatesForParamQuery, GenericPredicatesQuery,
-    ImplsForTraitQuery, ImplsInCrateQuery, StructDatumQuery, TraitDatumQuery, TraitSolveQuery,
+    HirDatabase, HirDatabaseStorage, ImplDatumQuery, ImplSelfTyQuery, ImplTraitQuery,
+    ImplsForTraitQuery, ImplsInCrateQuery, InternAssocTyValueQuery, InternChalkImplQuery,
+    InternTypeCtorQuery, StructDatumQuery, TraitDatumQuery, TraitSolveQuery, TraitSolverQuery,
    TyQuery, ValueTyQuery,
 };
diff --git a/crates/ra_hir_def/src/find_path.rs b/crates/ra_hir_def/src/find_path.rs
index 8cc2fb160..43b9b124a 100644
--- a/crates/ra_hir_def/src/find_path.rs
+++ b/crates/ra_hir_def/src/find_path.rs
@@ -7,10 +7,39 @@ use crate::{
    visibility::Visibility,
    CrateId, ModuleDefId, ModuleId,
 };
-use hir_expand::name::Name;
+use hir_expand::name::{known, Name};
+use test_utils::tested_by;
 const MAX_PATH_LEN: usize = 15;
+impl ModPath {
+    fn starts_with_std(&self) -> bool {
+        self.segments.first().filter(|&first_segment| first_segment == &known::std).is_some()
+    }
+    // When std library is present, paths starting with `std::`
+    // should be preferred over paths starting with `core::` and `alloc::`
+    fn should_start_with_std(&self) -> bool {
+        self.segments
+            .first()
+            .filter(|&first_segment| {
+                first_segment == &known::alloc || first_segment == &known::core
+            })
+            .is_some()
+    }
+    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,
+            }
+    }
+}
 // FIXME: handle local items
 /// Find a path that can be used to refer to a certain item. This can depend on
@@ -112,23 +141,27 @@ fn find_path_inner(
            Some(path) => path,
        };
        path.segments.push(name);
-        if path_len(&path) < best_path_len {
-            best_path_len = path_len(&path);
+        let new_path =
-            best_path = Some(path);
+            if let Some(best_path) = best_path { select_best_path(best_path, path) } else { path };
-        }
+        best_path_len = new_path.len();
+        best_path = Some(new_path);
    }
    best_path
 }
-fn path_len(path: &ModPath) -> usize {
+fn select_best_path(old_path: ModPath, new_path: ModPath) -> ModPath {
-    path.segments.len()
+    if old_path.starts_with_std() && new_path.should_start_with_std() {
-        + match path.kind {
+        tested_by!(prefer_std_paths);
-            PathKind::Plain => 0,
+        old_path
-            PathKind::Super(i) => i as usize,
+    } else if new_path.starts_with_std() && old_path.should_start_with_std() {
-            PathKind::Crate => 1,
+        tested_by!(prefer_std_paths);
-            PathKind::Abs => 0,
+        new_path
-            PathKind::DollarCrate(_) => 1,
+    } else if new_path.len() < old_path.len() {
-        }
+        new_path
+    } else {
+        old_path
+    }
 }
 fn find_importable_locations(
@@ -201,6 +234,7 @@ mod tests {
    use hir_expand::hygiene::Hygiene;
    use ra_db::fixture::WithFixture;
    use ra_syntax::ast::AstNode;
+    use test_utils::covers;
    /// `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
@@ -452,4 +486,41 @@ mod tests {
        "#;
        check_found_path(code, "crate::foo::S");
    }
+    #[test]
+    fn prefer_std_paths_over_alloc() {
+        covers!(prefer_std_paths);
+        let code = r#"
+        //- /main.rs crate:main deps:alloc,std
+        <|>
+        //- /std.rs crate:std deps:alloc
+        pub mod sync {
+            pub use alloc::sync::Arc;
+        }
+        //- /zzz.rs crate:alloc
+        pub mod sync {
+            pub struct Arc;
+        }
+        "#;
+        check_found_path(code, "std::sync::Arc");
+    }
+    #[test]
+    fn prefer_shorter_paths_if_not_alloc() {
+        let code = r#"
+        //- /main.rs crate:main deps:megaalloc,std
+        <|>
+        //- /std.rs crate:std deps:megaalloc
+        pub mod sync {
+            pub use megaalloc::sync::Arc;
+        }
+        //- /zzz.rs crate:megaalloc
+        pub struct Arc;
+        "#;
+        check_found_path(code, "megaalloc::Arc");
+    }
 }
diff --git a/crates/ra_hir_def/src/marks.rs b/crates/ra_hir_def/src/marks.rs
index 457ba4abe..daa49d5f1 100644
--- a/crates/ra_hir_def/src/marks.rs
+++ b/crates/ra_hir_def/src/marks.rs
@@ -13,4 +13,5 @@ test_utils::marks!(
    macro_dollar_crate_self
    macro_dollar_crate_other
    infer_resolve_while_let
+    prefer_std_paths
 );
diff --git a/crates/ra_hir_def/src/nameres.rs b/crates/ra_hir_def/src/nameres.rs
index 27c12e46c..852304dd0 100644
--- a/crates/ra_hir_def/src/nameres.rs
+++ b/crates/ra_hir_def/src/nameres.rs
@@ -229,6 +229,46 @@ impl CrateDefMap {
            self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path, shadow);
        (res.resolved_def, res.segment_index)
    }
+    // FIXME: this can use some more human-readable format (ideally, an IR
+    // even), as this should be a great debugging aid.
+    pub fn dump(&self) -> String {
+        let mut buf = String::new();
+        go(&mut buf, self, "\ncrate", self.root);
+        return buf.trim().to_string();
+        fn go(buf: &mut String, map: &CrateDefMap, path: &str, module: LocalModuleId) {
+            *buf += path;
+            *buf += "\n";
+            let mut entries: Vec<_> = map.modules[module].scope.resolutions().collect();
+            entries.sort_by_key(|(name, _)| name.clone());
+            for (name, def) in entries {
+                *buf += &format!("{}:", name);
+                if def.types.is_some() {
+                    *buf += " t";
+                }
+                if def.values.is_some() {
+                    *buf += " v";
+                }
+                if def.macros.is_some() {
+                    *buf += " m";
+                }
+                if def.is_none() {
+                    *buf += " _";
+                }
+                *buf += "\n";
+            }
+            for (name, child) in map.modules[module].children.iter() {
+                let path = path.to_string() + &format!("::{}", name);
+                go(buf, map, &path, *child);
+            }
+        }
+    }
 }
 impl ModuleData {
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index 78bcdc850..82f0f835c 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -10,11 +10,10 @@ use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, SourceDatabase};
 use test_utils::covers;
-use crate::{db::DefDatabase, nameres::*, test_db::TestDB, LocalModuleId};
+use crate::{db::DefDatabase, nameres::*, test_db::TestDB};
 fn def_map(fixture: &str) -> String {
-    let dm = compute_crate_def_map(fixture);
+    compute_crate_def_map(fixture).dump()
-    render_crate_def_map(&dm)
 }
 fn compute_crate_def_map(fixture: &str) -> Arc<CrateDefMap> {
@@ -23,44 +22,6 @@ fn compute_crate_def_map(fixture: &str) -> Arc<CrateDefMap> {
    db.crate_def_map(krate)
 }
-fn render_crate_def_map(map: &CrateDefMap) -> String {
-    let mut buf = String::new();
-    go(&mut buf, map, "\ncrate", map.root);
-    return buf.trim().to_string();
-    fn go(buf: &mut String, map: &CrateDefMap, path: &str, module: LocalModuleId) {
-        *buf += path;
-        *buf += "\n";
-        let mut entries: Vec<_> = map.modules[module].scope.resolutions().collect();
-        entries.sort_by_key(|(name, _)| name.clone());
-        for (name, def) in entries {
-            *buf += &format!("{}:", name);
-            if def.types.is_some() {
-                *buf += " t";
-            }
-            if def.values.is_some() {
-                *buf += " v";
-            }
-            if def.macros.is_some() {
-                *buf += " m";
-            }
-            if def.is_none() {
-                *buf += " _";
-            }
-            *buf += "\n";
-        }
-        for (name, child) in map.modules[module].children.iter() {
-            let path = path.to_string() + &format!("::{}", name);
-            go(buf, map, &path, *child);
-        }
-    }
-}
 #[test]
 fn crate_def_map_smoke_test() {
    let map = def_map(
diff --git a/crates/ra_hir_expand/src/name.rs b/crates/ra_hir_expand/src/name.rs
index b3fa1efba..b2e10f445 100644
--- a/crates/ra_hir_expand/src/name.rs
+++ b/crates/ra_hir_expand/src/name.rs
@@ -141,6 +141,8 @@ pub mod known {
        macro_rules,
        // Components of known path (value or mod name)
        std,
+        core,
+        alloc,
        iter,
        ops,
        future,
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 908e4862d..08d501ccd 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -847,7 +847,7 @@ impl HirDisplay for ApplicationTy {
            }
            TypeCtor::Array => {
                let t = self.parameters.as_single();
-                write!(f, "[{};_]", t.display(f.db))?;
+                write!(f, "[{}; _]", t.display(f.db))?;
            }
            TypeCtor::RawPtr(m) => {
                let t = self.parameters.as_single();
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 7e99a42ed..76a1b46c0 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -71,42 +71,42 @@ fn test2() {
    [82; 93) '{ loop {} }': T
    [84; 91) 'loop {}': !
    [89; 91) '{}': ()
-    [122; 133) '{ loop {} }': *mut [T;_]
+    [122; 133) '{ loop {} }': *mut [T; _]
    [124; 131) 'loop {}': !
    [129; 131) '{}': ()
    [160; 173) '{     gen() }': *mut [U]
-    [166; 169) 'gen': fn gen<U>() -> *mut [T;_]
+    [166; 169) 'gen': fn gen<U>() -> *mut [T; _]
-    [166; 171) 'gen()': *mut [U;_]
+    [166; 171) 'gen()': *mut [U; _]
    [186; 420) '{     ...rr); }': ()
-    [196; 199) 'arr': &[u8;_]
+    [196; 199) 'arr': &[u8; _]
-    [212; 216) '&[1]': &[u8;_]
+    [212; 216) '&[1]': &[u8; _]
-    [213; 216) '[1]': [u8;_]
+    [213; 216) '[1]': [u8; _]
    [214; 215) '1': u8
    [227; 228) 'a': &[u8]
-    [237; 240) 'arr': &[u8;_]
+    [237; 240) 'arr': &[u8; _]
    [250; 251) 'b': u8
    [254; 255) 'f': fn f<u8>(&[T]) -> T
    [254; 260) 'f(arr)': u8
-    [256; 259) 'arr': &[u8;_]
+    [256; 259) 'arr': &[u8; _]
    [270; 271) 'c': &[u8]
    [280; 287) '{ arr }': &[u8]
-    [282; 285) 'arr': &[u8;_]
+    [282; 285) 'arr': &[u8; _]
    [297; 298) 'd': u8
    [301; 302) 'g': fn g<u8>(S<&[T]>) -> T
    [301; 316) 'g(S { a: arr })': u8
    [303; 315) 'S { a: arr }': S<&[u8]>
-    [310; 313) 'arr': &[u8;_]
+    [310; 313) 'arr': &[u8; _]
-    [326; 327) 'e': [&[u8];_]
+    [326; 327) 'e': [&[u8]; _]
-    [341; 346) '[arr]': [&[u8];_]
+    [341; 346) '[arr]': [&[u8]; _]
-    [342; 345) 'arr': &[u8;_]
+    [342; 345) 'arr': &[u8; _]
-    [356; 357) 'f': [&[u8];_]
+    [356; 357) 'f': [&[u8]; _]
-    [371; 379) '[arr; 2]': [&[u8];_]
+    [371; 379) '[arr; 2]': [&[u8]; _]
-    [372; 375) 'arr': &[u8;_]
+    [372; 375) 'arr': &[u8; _]
    [377; 378) '2': usize
    [389; 390) 'g': (&[u8], &[u8])
    [407; 417) '(arr, arr)': (&[u8], &[u8])
-    [408; 411) 'arr': &[u8;_]
+    [408; 411) 'arr': &[u8; _]
-    [413; 416) 'arr': &[u8;_]
+    [413; 416) 'arr': &[u8; _]
    "###
    );
 }
@@ -122,8 +122,8 @@ fn test() {
        @r###"
    [11; 40) '{     ...[1]; }': ()
    [21; 22) 'x': &[i32]
-    [33; 37) '&[1]': &[i32;_]
+    [33; 37) '&[1]': &[i32; _]
-    [34; 37) '[1]': [i32;_]
+    [34; 37) '[1]': [i32; _]
    [35; 36) '1': i32
    "###);
 }
@@ -159,22 +159,22 @@ fn test(a: A<[u8; 2]>, b: B<[u8; 2]>, c: C<[u8; 2]>) {
    [334; 335) 'x': C<[T]>
    [355; 360) '{ x }': C<[T]>
    [357; 358) 'x': C<[T]>
-    [370; 371) 'a': A<[u8;_]>
+    [370; 371) 'a': A<[u8; _]>
-    [385; 386) 'b': B<[u8;_]>
+    [385; 386) 'b': B<[u8; _]>
-    [400; 401) 'c': C<[u8;_]>
+    [400; 401) 'c': C<[u8; _]>
    [415; 481) '{     ...(c); }': ()
    [425; 426) 'd': A<[{unknown}]>
    [429; 433) 'foo1': fn foo1<{unknown}>(A<[T]>) -> A<[T]>
    [429; 436) 'foo1(a)': A<[{unknown}]>
-    [434; 435) 'a': A<[u8;_]>
+    [434; 435) 'a': A<[u8; _]>
    [446; 447) 'e': B<[u8]>
    [450; 454) 'foo2': fn foo2<u8>(B<[T]>) -> B<[T]>
    [450; 457) 'foo2(b)': B<[u8]>
-    [455; 456) 'b': B<[u8;_]>
+    [455; 456) 'b': B<[u8; _]>
    [467; 468) 'f': C<[u8]>
    [471; 475) 'foo3': fn foo3<u8>(C<[T]>) -> C<[T]>
    [471; 478) 'foo3(c)': C<[u8]>
-    [476; 477) 'c': C<[u8;_]>
+    [476; 477) 'c': C<[u8; _]>
    "###
    );
 }
@@ -204,12 +204,12 @@ fn test() {
    [72; 97) '{     ...     }': &[i32]
    [82; 85) 'foo': fn foo<i32>(&[T]) -> &[T]
    [82; 91) 'foo(&[1])': &[i32]
-    [86; 90) '&[1]': &[i32;_]
+    [86; 90) '&[1]': &[i32; _]
-    [87; 90) '[1]': [i32;_]
+    [87; 90) '[1]': [i32; _]
    [88; 89) '1': i32
-    [103; 123) '{     ...     }': &[i32;_]
+    [103; 123) '{     ...     }': &[i32; _]
-    [113; 117) '&[1]': &[i32;_]
+    [113; 117) '&[1]': &[i32; _]
-    [114; 117) '[1]': [i32;_]
+    [114; 117) '[1]': [i32; _]
    [115; 116) '1': i32
    "###
    );
@@ -237,15 +237,15 @@ fn test() {
    [60; 61) 'x': &[i32]
    [64; 123) 'if tru...     }': &[i32]
    [67; 71) 'true': bool
-    [72; 92) '{     ...     }': &[i32;_]
+    [72; 92) '{     ...     }': &[i32; _]
-    [82; 86) '&[1]': &[i32;_]
+    [82; 86) '&[1]': &[i32; _]
-    [83; 86) '[1]': [i32;_]
+    [83; 86) '[1]': [i32; _]
    [84; 85) '1': i32
    [98; 123) '{     ...     }': &[i32]
    [108; 111) 'foo': fn foo<i32>(&[T]) -> &[T]
    [108; 117) 'foo(&[1])': &[i32]
-    [112; 116) '&[1]': &[i32;_]
+    [112; 116) '&[1]': &[i32; _]
-    [113; 116) '[1]': [i32;_]
+    [113; 116) '[1]': [i32; _]
    [114; 115) '1': i32
    "###
    );
@@ -277,16 +277,16 @@ fn test(i: i32) {
    [88; 89) '2': i32
    [93; 96) 'foo': fn foo<i32>(&[T]) -> &[T]
    [93; 102) 'foo(&[2])': &[i32]
-    [97; 101) '&[2]': &[i32;_]
+    [97; 101) '&[2]': &[i32; _]
-    [98; 101) '[2]': [i32;_]
+    [98; 101) '[2]': [i32; _]
    [99; 100) '2': i32
    [112; 113) '1': i32
-    [117; 121) '&[1]': &[i32;_]
+    [117; 121) '&[1]': &[i32; _]
-    [118; 121) '[1]': [i32;_]
+    [118; 121) '[1]': [i32; _]
    [119; 120) '1': i32
    [131; 132) '_': i32
-    [136; 140) '&[3]': &[i32;_]
+    [136; 140) '&[3]': &[i32; _]
-    [137; 140) '[3]': [i32;_]
+    [137; 140) '[3]': [i32; _]
    [138; 139) '3': i32
    "###
    );
@@ -316,18 +316,18 @@ fn test(i: i32) {
    [70; 147) 'match ...     }': &[i32]
    [76; 77) 'i': i32
    [88; 89) '1': i32
-    [93; 97) '&[1]': &[i32;_]
+    [93; 97) '&[1]': &[i32; _]
-    [94; 97) '[1]': [i32;_]
+    [94; 97) '[1]': [i32; _]
    [95; 96) '1': i32
    [107; 108) '2': i32
    [112; 115) 'foo': fn foo<i32>(&[T]) -> &[T]
    [112; 121) 'foo(&[2])': &[i32]
-    [116; 120) '&[2]': &[i32;_]
+    [116; 120) '&[2]': &[i32; _]
-    [117; 120) '[2]': [i32;_]
+    [117; 120) '[2]': [i32; _]
    [118; 119) '2': i32
    [131; 132) '_': i32
-    [136; 140) '&[3]': &[i32;_]
+    [136; 140) '&[3]': &[i32; _]
-    [137; 140) '[3]': [i32;_]
+    [137; 140) '[3]': [i32; _]
    [138; 139) '3': i32
    "###
    );
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index aa948dcbf..02bab6dbe 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -102,7 +102,7 @@ fn test() {
    [11; 48) '{     ...&y]; }': ()
    [21; 22) 'y': &{unknown}
    [25; 32) 'unknown': &{unknown}
-    [38; 45) '[y, &y]': [&&{unknown};_]
+    [38; 45) '[y, &y]': [&&{unknown}; _]
    [39; 40) 'y': &{unknown}
    [42; 44) '&y': &&{unknown}
    [43; 44) 'y': &{unknown}
@@ -128,7 +128,7 @@ fn test() {
    [25; 32) 'unknown': &&{unknown}
    [42; 43) 'y': &&{unknown}
    [46; 53) 'unknown': &&{unknown}
-    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
+    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); _]
    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
    [61; 62) 'x': &&{unknown}
    [64; 65) 'y': &&{unknown}
@@ -180,8 +180,8 @@ fn test_line_buffer() {
 "#),
        @r###"
    [23; 53) '{     ...n']; }': ()
-    [29; 50) '&[0, b...b'\n']': &[u8;_]
+    [29; 50) '&[0, b...b'\n']': &[u8; _]
-    [30; 50) '[0, b'...b'\n']': [u8;_]
+    [30; 50) '[0, b'...b'\n']': [u8; _]
    [31; 32) '0': u8
    [34; 39) 'b'\n'': u8
    [41; 42) '1': u8
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index b7204ec00..fdab9c187 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -28,7 +28,7 @@ mod boxed {
 "#,
    );
-    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
+    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; _]>)", type_at_pos(&db, pos));
 }
 #[test]
@@ -1061,55 +1061,55 @@ fn test(x: &str, y: isize) {
    [9; 10) 'x': &str
    [18; 19) 'y': isize
    [28; 293) '{     ... []; }': ()
-    [38; 39) 'a': [&str;_]
+    [38; 39) 'a': [&str; _]
-    [42; 45) '[x]': [&str;_]
+    [42; 45) '[x]': [&str; _]
    [43; 44) 'x': &str
-    [55; 56) 'b': [[&str;_];_]
+    [55; 56) 'b': [[&str; _]; _]
-    [59; 65) '[a, a]': [[&str;_];_]
+    [59; 65) '[a, a]': [[&str; _]; _]
-    [60; 61) 'a': [&str;_]
+    [60; 61) 'a': [&str; _]
-    [63; 64) 'a': [&str;_]
+    [63; 64) 'a': [&str; _]
-    [75; 76) 'c': [[[&str;_];_];_]
+    [75; 76) 'c': [[[&str; _]; _]; _]
-    [79; 85) '[b, b]': [[[&str;_];_];_]
+    [79; 85) '[b, b]': [[[&str; _]; _]; _]
-    [80; 81) 'b': [[&str;_];_]
+    [80; 81) 'b': [[&str; _]; _]
-    [83; 84) 'b': [[&str;_];_]
+    [83; 84) 'b': [[&str; _]; _]
-    [96; 97) 'd': [isize;_]
+    [96; 97) 'd': [isize; _]
-    [100; 112) '[y, 1, 2, 3]': [isize;_]
+    [100; 112) '[y, 1, 2, 3]': [isize; _]
    [101; 102) 'y': isize
    [104; 105) '1': isize
    [107; 108) '2': isize
    [110; 111) '3': isize
-    [122; 123) 'd': [isize;_]
+    [122; 123) 'd': [isize; _]
-    [126; 138) '[1, y, 2, 3]': [isize;_]
+    [126; 138) '[1, y, 2, 3]': [isize; _]
    [127; 128) '1': isize
    [130; 131) 'y': isize
    [133; 134) '2': isize
    [136; 137) '3': isize
-    [148; 149) 'e': [isize;_]
+    [148; 149) 'e': [isize; _]
-    [152; 155) '[y]': [isize;_]
+    [152; 155) '[y]': [isize; _]
    [153; 154) 'y': isize
-    [165; 166) 'f': [[isize;_];_]
+    [165; 166) 'f': [[isize; _]; _]
-    [169; 175) '[d, d]': [[isize;_];_]
+    [169; 175) '[d, d]': [[isize; _]; _]
-    [170; 171) 'd': [isize;_]
+    [170; 171) 'd': [isize; _]
-    [173; 174) 'd': [isize;_]
+    [173; 174) 'd': [isize; _]
-    [185; 186) 'g': [[isize;_];_]
+    [185; 186) 'g': [[isize; _]; _]
-    [189; 195) '[e, e]': [[isize;_];_]
+    [189; 195) '[e, e]': [[isize; _]; _]
-    [190; 191) 'e': [isize;_]
+    [190; 191) 'e': [isize; _]
-    [193; 194) 'e': [isize;_]
+    [193; 194) 'e': [isize; _]
-    [206; 207) 'h': [i32;_]
+    [206; 207) 'h': [i32; _]
-    [210; 216) '[1, 2]': [i32;_]
+    [210; 216) '[1, 2]': [i32; _]
    [211; 212) '1': i32
    [214; 215) '2': i32
-    [226; 227) 'i': [&str;_]
+    [226; 227) 'i': [&str; _]
-    [230; 240) '["a", "b"]': [&str;_]
+    [230; 240) '["a", "b"]': [&str; _]
    [231; 234) '"a"': &str
    [236; 239) '"b"': &str
-    [251; 252) 'b': [[&str;_];_]
+    [251; 252) 'b': [[&str; _]; _]
-    [255; 265) '[a, ["b"]]': [[&str;_];_]
+    [255; 265) '[a, ["b"]]': [[&str; _]; _]
-    [256; 257) 'a': [&str;_]
+    [256; 257) 'a': [&str; _]
-    [259; 264) '["b"]': [&str;_]
+    [259; 264) '["b"]': [&str; _]
    [260; 263) '"b"': &str
-    [275; 276) 'x': [u8;_]
+    [275; 276) 'x': [u8; _]
-    [288; 290) '[]': [u8;_]
+    [288; 290) '[]': [u8; _]
    "###
    );
 }
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index bc20a49cc..a6ac18f86 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -479,7 +479,7 @@ fn indexing_arrays() {
        @r###"
    [10; 26) '{ &mut...[2]; }': ()
    [12; 23) '&mut [9][2]': &mut {unknown}
-    [17; 20) '[9]': [i32;_]
+    [17; 20) '[9]': [i32; _]
    [17; 23) '[9][2]': {unknown}
    [18; 19) '9': i32
    [21; 22) '2': i32
diff --git a/crates/ra_ide/src/change.rs b/crates/ra_ide/src/change.rs
index ce617840c..45a58690b 100644
--- a/crates/ra_ide/src/change.rs
+++ b/crates/ra_ide/src/change.rs
@@ -301,45 +301,74 @@ impl RootDatabase {
            )*}
        }
        sweep_each_query![
+            // SourceDatabase
            ra_db::ParseQuery
            ra_db::SourceRootCratesQuery
+            // AstDatabase
            hir::db::AstIdMapQuery
-            hir::db::ParseMacroQuery
+            hir::db::InternMacroQuery
-            hir::db::MacroDefQuery
            hir::db::MacroArgQuery
+            hir::db::MacroDefQuery
+            hir::db::ParseMacroQuery
            hir::db::MacroExpandQuery
+            // DefDatabase
+            hir::db::RawItemsQuery
+            hir::db::ComputeCrateDefMapQuery
            hir::db::StructDataQuery
+            hir::db::UnionDataQuery
            hir::db::EnumDataQuery
+            hir::db::ImplDataQuery
            hir::db::TraitDataQuery
-            hir::db::RawItemsQuery
-            hir::db::ComputeCrateDefMapQuery
-            hir::db::GenericParamsQuery
-            hir::db::FunctionDataQuery
            hir::db::TypeAliasDataQuery
+            hir::db::FunctionDataQuery
            hir::db::ConstDataQuery
            hir::db::StaticDataQuery
+            hir::db::BodyWithSourceMapQuery
+            hir::db::BodyQuery
+            hir::db::ExprScopesQuery
+            hir::db::GenericParamsQuery
+            hir::db::AttrsQuery
            hir::db::ModuleLangItemsQuery
            hir::db::CrateLangItemsQuery
            hir::db::LangItemQuery
            hir::db::DocumentationQuery
-            hir::db::ExprScopesQuery
+            // InternDatabase
+            hir::db::InternFunctionQuery
+            hir::db::InternStructQuery
+            hir::db::InternUnionQuery
+            hir::db::InternEnumQuery
+            hir::db::InternConstQuery
+            hir::db::InternStaticQuery
+            hir::db::InternTraitQuery
+            hir::db::InternTypeAliasQuery
+            hir::db::InternImplQuery
+            // HirDatabase
            hir::db::DoInferQuery
            hir::db::TyQuery
            hir::db::ValueTyQuery
+            hir::db::ImplSelfTyQuery
+            hir::db::ImplTraitQuery
            hir::db::FieldTypesQuery
            hir::db::CallableItemSignatureQuery
+            hir::db::GenericPredicatesForParamQuery
            hir::db::GenericPredicatesQuery
            hir::db::GenericDefaultsQuery
-            hir::db::BodyWithSourceMapQuery
-            hir::db::BodyQuery
            hir::db::ImplsInCrateQuery
            hir::db::ImplsForTraitQuery
+            hir::db::TraitSolverQuery
+            hir::db::InternTypeCtorQuery
+            hir::db::InternChalkImplQuery
+            hir::db::InternAssocTyValueQuery
            hir::db::AssociatedTyDataQuery
+            hir::db::AssociatedTyValueQuery
+            hir::db::TraitSolveQuery
            hir::db::TraitDatumQuery
            hir::db::StructDatumQuery
            hir::db::ImplDatumQuery
-            hir::db::ImplDataQuery
-            hir::db::TraitSolveQuery
        ];
        acc.sort_by_key(|it| std::cmp::Reverse(it.1));
        acc
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 15bf519c9..d850ded37 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -5,11 +5,18 @@ mod handlers;
 mod subscriptions;
 pub(crate) mod pending_requests;
-use std::{error::Error, fmt, panic, path::PathBuf, sync::Arc, time::Instant};
+use std::{
+    env,
+    error::Error,
+    fmt, panic,
+    path::PathBuf,
+    sync::Arc,
+    time::{Duration, Instant},
+};
 use crossbeam_channel::{select, unbounded, RecvError, Sender};
 use lsp_server::{Connection, ErrorCode, Message, Notification, Request, RequestId, Response};
-use lsp_types::{ClientCapabilities, NumberOrString, Url};
+use lsp_types::{ClientCapabilities, NumberOrString};
 use ra_cargo_watch::{CheckOptions, CheckTask};
 use ra_ide::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
 use ra_prof::profile;
@@ -352,7 +359,7 @@ fn loop_turn(
            world_state.maybe_collect_garbage();
            loop_state.in_flight_libraries -= 1;
        }
-        Event::CheckWatcher(task) => on_check_task(task, world_state, task_sender)?,
+        Event::CheckWatcher(task) => on_check_task(pool, task, world_state, task_sender)?,
        Event::Msg(msg) => match msg {
            Message::Request(req) => on_request(
                world_state,
@@ -425,6 +432,19 @@ fn loop_turn(
            loop_state.subscriptions.subscriptions(),
        )
    }
+    let loop_duration = loop_start.elapsed();
+    if loop_duration > Duration::from_millis(100) {
+        log::error!("overly long loop turn: {:?}", loop_duration);
+        if env::var("RA_PROFILE").is_ok() {
+            show_message(
+                req::MessageType::Error,
+                format!("overly long loop turn: {:?}", loop_duration),
+                &connection.sender,
+            );
+        }
+    }
    Ok(())
 }
@@ -452,7 +472,7 @@ fn on_request(
    world: &mut WorldState,
    pending_requests: &mut PendingRequests,
    pool: &ThreadPool,
-    sender: &Sender<Task>,
+    task_sender: &Sender<Task>,
    msg_sender: &Sender<Message>,
    request_received: Instant,
    req: Request,
@@ -461,7 +481,7 @@ fn on_request(
        req: Some(req),
        pool,
        world,
-        sender,
+        task_sender,
        msg_sender,
        pending_requests,
        request_received,
@@ -602,31 +622,23 @@ fn on_notification(
 }
 fn on_check_task(
+    pool: &ThreadPool,
    task: CheckTask,
    world_state: &mut WorldState,
    task_sender: &Sender<Task>,
 ) -> Result<()> {
-    match task {
+    let urls = match task {
        CheckTask::ClearDiagnostics => {
            let state = Arc::get_mut(&mut world_state.check_watcher.state)
                .expect("couldn't get check watcher state as mutable");
-            let cleared_files = state.clear();
+            state.clear()
-            // Send updated diagnostics for each cleared file
-            for url in cleared_files {
-                publish_diagnostics_for_url(&url, world_state, task_sender)?;
-            }
        }
        CheckTask::AddDiagnostic(url, diagnostic) => {
            let state = Arc::get_mut(&mut world_state.check_watcher.state)
                .expect("couldn't get check watcher state as mutable");
            state.add_diagnostic_with_fixes(url.clone(), diagnostic);
+            vec![url]
-            // We manually send a diagnostic update when the watcher asks
-            // us to, to avoid the issue of having to change the file to
-            // receive updated diagnostics.
-            publish_diagnostics_for_url(&url, world_state, task_sender)?;
        }
        CheckTask::Status(progress) => {
@@ -636,22 +648,30 @@ fn on_check_task(
            };
            let not = notification_new::<req::Progress>(params);
            task_sender.send(Task::Notify(not)).unwrap();
+            Vec::new()
        }
-    }
+    };
-    Ok(())
-}
+    let subscriptions = urls
+        .into_iter()
+        .map(|url| {
+            let path = url.to_file_path().map_err(|()| format!("invalid uri: {}", url))?;
+            Ok(world_state.vfs.read().path2file(&path).map(|it| FileId(it.0)))
+        })
+        .filter_map(|res| res.transpose())
+        .collect::<Result<Vec<_>>>()?;
+    // We manually send a diagnostic update when the watcher asks
+    // us to, to avoid the issue of having to change the file to
+    // receive updated diagnostics.
+    update_file_notifications_on_threadpool(
+        pool,
+        world_state.snapshot(),
+        false,
+        task_sender.clone(),
+        subscriptions,
+    );
-fn publish_diagnostics_for_url(
-    url: &Url,
-    world_state: &WorldState,
-    task_sender: &Sender<Task>,
-) -> Result<()> {
-    let path = url.to_file_path().map_err(|()| format!("invalid uri: {}", url))?;
-    if let Some(file_id) = world_state.vfs.read().path2file(&path) {
-        let params = handlers::publish_diagnostics(&world_state.snapshot(), FileId(file_id.0))?;
-        let not = notification_new::<req::PublishDiagnostics>(params);
-        task_sender.send(Task::Notify(not)).unwrap();
-    }
    Ok(())
 }
@@ -661,7 +681,7 @@ struct PoolDispatcher<'a> {
    world: &'a mut WorldState,
    pending_requests: &'a mut PendingRequests,
    msg_sender: &'a Sender<Message>,
-    sender: &'a Sender<Task>,
+    task_sender: &'a Sender<Task>,
    request_received: Instant,
 }
@@ -708,7 +728,7 @@ impl<'a> PoolDispatcher<'a> {
        self.pool.execute({
            let world = self.world.snapshot();
-            let sender = self.sender.clone();
+            let sender = self.task_sender.clone();
            move || {
                let result = f(world, params);
                let task = result_to_task::<R>(id, result);
@@ -786,7 +806,7 @@ fn update_file_notifications_on_threadpool(
    pool: &ThreadPool,
    world: WorldSnapshot,
    publish_decorations: bool,
-    sender: Sender<Task>,
+    task_sender: Sender<Task>,
    subscriptions: Vec<FileId>,
 ) {
    log::trace!("updating notifications for {:?}", subscriptions);
@@ -802,7 +822,7 @@ fn update_file_notifications_on_threadpool(
                    }
                    Ok(params) => {
                        let not = notification_new::<req::PublishDiagnostics>(params);
-                        sender.send(Task::Notify(not)).unwrap();
+                        task_sender.send(Task::Notify(not)).unwrap();
                    }
                }
            }
@@ -815,7 +835,7 @@ fn update_file_notifications_on_threadpool(
                    }
                    Ok(params) => {
                        let not = notification_new::<req::PublishDecorations>(params);
-                        sender.send(Task::Notify(not)).unwrap();
+                        task_sender.send(Task::Notify(not)).unwrap();
                    }
                }
            }
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index c7973ddf4..4a49e9f95 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -6,9 +6,9 @@ mod google_cpu_profiler;
 use std::{
    cell::RefCell,
+    collections::BTreeMap,
    collections::HashSet,
    io::{stderr, Write},
-    iter::repeat,
    mem,
    sync::{
        atomic::{AtomicBool, Ordering},
@@ -17,7 +17,6 @@ use std::{
    time::{Duration, Instant},
 };
-use itertools::Itertools;
 use once_cell::sync::Lazy;
 pub use crate::memory_usage::{Bytes, MemoryUsage};
@@ -216,7 +215,7 @@ impl Drop for Profiler {
                        // (otherwise we could print `0ms` despite user's `>0` filter when
                        // `duration` is just a few nanos).
                        if duration.as_millis() > longer_than.as_millis() {
-                            print(0, &stack.messages, &mut stdout.lock(), longer_than, None);
+                            print(&stack.messages, longer_than, &mut stdout.lock());
                        }
                        stack.messages.clear();
                    }
@@ -227,59 +226,85 @@ impl Drop for Profiler {
    }
 }
-fn print(
+fn print(msgs: &[Message], longer_than: Duration, out: &mut impl Write) {
-    lvl: usize,
-    msgs: &[Message],
-    out: &mut impl Write,
-    longer_than: Duration,
-    total: Option<Duration>,
-) {
    if msgs.is_empty() {
        return;
    }
-    // The index of the first element that will be included in the slice when we recurse.
+    let children_map = idx_to_children(msgs);
-    let mut next_start = 0;
+    let root_idx = msgs.len() - 1;
-    let indent = repeat("    ").take(lvl).collect::<String>();
+    print_for_idx(root_idx, &children_map, msgs, longer_than, out);
-    // We output hierarchy for long calls, but sum up all short calls
+}
-    let mut short = Vec::new();
+fn print_for_idx(
+    current_idx: usize,
+    children_map: &[Vec<usize>],
+    msgs: &[Message],
+    longer_than: Duration,
+    out: &mut impl Write,
+) {
+    let current = &msgs[current_idx];
+    let current_indent = "    ".repeat(current.level);
+    writeln!(out, "{}{:5}ms - {}", current_indent, current.duration.as_millis(), current.message)
+        .expect("printing profiling info");
+    let longer_than_millis = longer_than.as_millis();
+    let children_indices = &children_map[current_idx];
    let mut accounted_for = Duration::default();
-    for (i, &Message { level, duration, message: ref msg }) in msgs.iter().enumerate() {
+    let mut short_children = BTreeMap::new(); // Use `BTreeMap` to get deterministic output.
-        if level != lvl {
-            continue;
-        }
-        accounted_for += duration;
-        if duration.as_millis() > longer_than.as_millis() {
-            writeln!(out, "{}{:5}ms - {}", indent, duration.as_millis(), msg)
-                .expect("printing profiling info to stdout");
-            print(lvl + 1, &msgs[next_start..i], out, longer_than, Some(duration));
+    for child_idx in children_indices.iter() {
+        let child = &msgs[*child_idx];
+        if child.duration.as_millis() > longer_than_millis {
+            print_for_idx(*child_idx, children_map, msgs, longer_than, out);
        } else {
-            short.push((msg, duration))
+            let pair = short_children.entry(&child.message).or_insert((Duration::default(), 0));
+            pair.0 += child.duration;
+            pair.1 += 1;
        }
+        accounted_for += child.duration;
+    }
-        next_start = i + 1;
+    for (child_msg, (duration, count)) in short_children.iter() {
+        let millis = duration.as_millis();
+        writeln!(out, "    {}{:5}ms - {} ({} calls)", current_indent, millis, child_msg, count)
+            .expect("printing profiling info");
    }
-    short.sort_by_key(|(msg, _time)| *msg);
-    for (msg, entires) in short.iter().group_by(|(msg, _time)| msg).into_iter() {
+    let unaccounted_millis = (current.duration - accounted_for).as_millis();
-        let mut count = 0;
+    if !children_indices.is_empty()
-        let mut total_duration = Duration::default();
+        && unaccounted_millis > 0
-        entires.for_each(|(_msg, time)| {
+        && unaccounted_millis > longer_than_millis
-            count += 1;
+    {
-            total_duration += *time;
+        writeln!(out, "    {}{:5}ms - ???", current_indent, unaccounted_millis)
-        });
+            .expect("printing profiling info");
-        writeln!(out, "{}{:5}ms - {} ({} calls)", indent, total_duration.as_millis(), msg, count)
-            .expect("printing profiling info to stdout");
    }
+}
-    if let Some(total) = total {
+/// Returns a mapping from an index in the `msgs` to the vector with the indices of its children.
-        if let Some(unaccounted) = total.checked_sub(accounted_for) {
+///
-            let unaccounted_millis = unaccounted.as_millis();
+/// This assumes that the entries in `msgs` are in the order of when the calls to `profile` finish.
-            if unaccounted_millis > longer_than.as_millis() && unaccounted_millis > 0 {
+/// In other words, a postorder of the call graph. In particular, the root is the last element of
-                writeln!(out, "{}{:5}ms - ???", indent, unaccounted_millis)
+/// `msgs`.
-                    .expect("printing profiling info to stdout");
+fn idx_to_children(msgs: &[Message]) -> Vec<Vec<usize>> {
-            }
+    // Initialize with the index of the root; `msgs` and `ancestors` should be never empty.
+    assert!(!msgs.is_empty());
+    let mut ancestors = vec![msgs.len() - 1];
+    let mut result: Vec<Vec<usize>> = vec![vec![]; msgs.len()];
+    for (idx, msg) in msgs[..msgs.len() - 1].iter().enumerate().rev() {
+        // We need to find the parent of the current message, i.e., the last ancestor that has a
+        // level lower than the current message.
+        while msgs[*ancestors.last().unwrap()].level >= msg.level {
+            ancestors.pop();
        }
+        result[*ancestors.last().unwrap()].push(idx);
+        ancestors.push(idx);
+    }
+    // Note that above we visited all children from the last to the first one. Let's reverse vectors
+    // to get the more natural order where the first element is the first child.
+    for vec in result.iter_mut() {
+        vec.reverse();
    }
+    result
 }
 /// Prints backtrace to stderr, useful for debugging.
@@ -388,7 +413,7 @@ mod tests {
            Message { level: 1, duration: Duration::from_nanos(2), message: "bar".to_owned() },
            Message { level: 0, duration: Duration::from_millis(1), message: "foo".to_owned() },
        ];
-        print(0, &msgs, &mut result, Duration::from_millis(0), Some(Duration::from_millis(1)));
+        print(&msgs, Duration::from_millis(0), &mut result);
        // The calls to `bar` are so short that they'll be rounded to 0ms and should get collapsed
        // when printing.
        assert_eq!(
@@ -404,7 +429,7 @@ mod tests {
            Message { level: 1, duration: Duration::from_millis(2), message: "bar".to_owned() },
            Message { level: 0, duration: Duration::from_millis(5), message: "foo".to_owned() },
        ];
-        print(0, &msgs, &mut result, Duration::from_millis(0), Some(Duration::from_millis(1)));
+        print(&msgs, Duration::from_millis(0), &mut result);
        assert_eq!(
            std::str::from_utf8(&result).unwrap().lines().collect::<Vec<_>>(),
            vec![
@@ -426,7 +451,7 @@ mod tests {
            Message { level: 1, duration: Duration::from_millis(4), message: "bar".to_owned() },
            Message { level: 0, duration: Duration::from_millis(9), message: "foo".to_owned() },
        ];
-        print(0, &msgs, &mut result, Duration::from_millis(0), None);
+        print(&msgs, Duration::from_millis(0), &mut result);
        assert_eq!(
            std::str::from_utf8(&result).unwrap().lines().collect::<Vec<_>>(),
            vec![
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 659f77b71..336c594a6 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -21,6 +21,12 @@ pub use difference::Changeset as __Changeset;
 pub const CURSOR_MARKER: &str = "<|>";
+/// Asserts that two strings are equal, otherwise displays a rich diff between them.
+///
+/// The diff shows changes from the "original" left string to the "actual" right string.
+///
+/// All arguments starting from and including the 3rd one are passed to
+/// `eprintln!()` macro in case of text inequality.
 #[macro_export]
 macro_rules! assert_eq_text {
    ($left:expr, $right:expr) => {
@@ -42,6 +48,7 @@ macro_rules! assert_eq_text {
    }};
 }
+/// Infallible version of `try_extract_offset()`.
 pub fn extract_offset(text: &str) -> (TextUnit, String) {
    match try_extract_offset(text) {
        None => panic!("text should contain cursor marker"),
@@ -49,6 +56,8 @@ pub fn extract_offset(text: &str) -> (TextUnit, String) {
    }
 }
+/// Returns the offset of the first occurence of `<|>` marker and the copy of `text`
+/// without the marker.
 fn try_extract_offset(text: &str) -> Option<(TextUnit, String)> {
    let cursor_pos = text.find(CURSOR_MARKER)?;
    let mut new_text = String::with_capacity(text.len() - CURSOR_MARKER.len());
@@ -58,6 +67,7 @@ fn try_extract_offset(text: &str) -> Option<(TextUnit, String)> {
    Some((cursor_pos, new_text))
 }
+/// Infallible version of `try_extract_range()`.
 pub fn extract_range(text: &str) -> (TextRange, String) {
    match try_extract_range(text) {
        None => panic!("text should contain cursor marker"),
@@ -65,6 +75,8 @@ pub fn extract_range(text: &str) -> (TextRange, String) {
    }
 }
+/// Returns `TextRange` between the first two markers `<|>...<|>` and the copy
+/// of `text` without both of these markers.
 fn try_extract_range(text: &str) -> Option<(TextRange, String)> {
    let (start, text) = try_extract_offset(text)?;
    let (end, text) = try_extract_offset(&text)?;
@@ -85,6 +97,11 @@ impl From<RangeOrOffset> for TextRange {
    }
 }
+/// Extracts `TextRange` or `TextUnit` depending on the amount of `<|>` markers
+/// found in `text`.
+///
+/// # Panics
+/// Panics if no `<|>` marker is present in the `text`.
 pub fn extract_range_or_offset(text: &str) -> (RangeOrOffset, String) {
    if let Some((range, text)) = try_extract_range(text) {
        return (RangeOrOffset::Range(range), text);
@@ -93,7 +110,7 @@ pub fn extract_range_or_offset(text: &str) -> (RangeOrOffset, String) {
    (RangeOrOffset::Offset(offset), text)
 }
-/// Extracts ranges, marked with `<tag> </tag>` paris from the `text`
+/// Extracts ranges, marked with `<tag> </tag>` pairs from the `text`
 pub fn extract_ranges(mut text: &str, tag: &str) -> (Vec<TextRange>, String) {
    let open = format!("<{}>", tag);
    let close = format!("</{}>", tag);
@@ -127,9 +144,9 @@ pub fn extract_ranges(mut text: &str, tag: &str) -> (Vec<TextRange>, String) {
    (ranges, res)
 }
+/// Inserts `<|>` marker into the `text` at `offset`.
 pub fn add_cursor(text: &str, offset: TextUnit) -> String {
-    let offset: u32 = offset.into();
+    let offset: usize = offset.to_usize();
-    let offset: usize = offset as usize;
    let mut res = String::new();
    res.push_str(&text[..offset]);
    res.push_str("<|>");
@@ -152,19 +169,6 @@ pub struct FixtureEntry {
 ///  // - other meta
 ///  ```
 pub fn parse_fixture(fixture: &str) -> Vec<FixtureEntry> {
-    let mut res = Vec::new();
-    let mut buf = String::new();
-    let mut meta: Option<&str> = None;
-    macro_rules! flush {
-        () => {
-            if let Some(meta) = meta {
-                res.push(FixtureEntry { meta: meta.to_string(), text: buf.clone() });
-                buf.clear();
-            }
-        };
-    };
    let margin = fixture
        .lines()
        .filter(|it| it.trim_start().starts_with("//-"))
@@ -172,7 +176,7 @@ pub fn parse_fixture(fixture: &str) -> Vec<FixtureEntry> {
        .next()
        .expect("empty fixture");
-    let lines = fixture
+    let mut lines = fixture
        .split('\n') // don't use `.lines` to not drop `\r\n`
        .filter_map(|line| {
            if line.len() >= margin {
@@ -184,17 +188,16 @@ pub fn parse_fixture(fixture: &str) -> Vec<FixtureEntry> {
            }
        });
-    for line in lines {
+    let mut res: Vec<FixtureEntry> = Vec::new();
+    for line in lines.by_ref() {
        if line.starts_with("//-") {
-            flush!();
+            let meta = line["//-".len()..].trim().to_string();
-            buf.clear();
+            res.push(FixtureEntry { meta, text: String::new() })
-            meta = Some(line["//-".len()..].trim());
+        } else if let Some(entry) = res.last_mut() {
-            continue;
+            entry.text.push_str(line);
+            entry.text.push('\n');
        }
-        buf.push_str(line);
-        buf.push('\n');
    }
-    flush!();
    res
 }
@@ -236,11 +239,10 @@ fn lines_match_works() {
    assert!(!lines_match("b", "cb"));
 }
-// Compares JSON object for approximate equality.
+/// Compares JSON object for approximate equality.
-// You can use `[..]` wildcard in strings (useful for OS dependent things such
+/// You can use `[..]` wildcard in strings (useful for OS dependent things such
-// as paths).  You can use a `"{...}"` string literal as a wildcard for
+/// as paths). You can use a `"{...}"` string literal as a wildcard for
-// arbitrary nested JSON (useful for parts of object emitted by other programs
+/// arbitrary nested JSON. Arrays are sorted before comparison.
-// (e.g. rustc) rather than Cargo itself).  Arrays are sorted before comparison.
 pub fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a Value, &'a Value)> {
    use serde_json::Value::*;
    match (expected, actual) {
@@ -286,6 +288,14 @@ pub fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a
    }
 }
+/// Calls callback `f` with input code and file paths of all `.rs` files from `test_data_dir`
+/// subdirectories defined by `paths`.
+///
+/// If the content of the matching `.txt` file differs from the output of `f()`
+/// the test will fail.
+///
+/// If there is no matching `.txt` file it will be created and filled with the
+/// output of `f()`, but the test will fail.
 pub fn dir_tests<F>(test_data_dir: &Path, paths: &[&str], f: F)
 where
    F: Fn(&str, &Path) -> String,
@@ -307,6 +317,7 @@ where
    }
 }
+/// Collects all `.rs` files from `test_data_dir` subdirectories defined by `paths`.
 pub fn collect_tests(test_data_dir: &Path, paths: &[&str]) -> Vec<(PathBuf, String)> {
    paths
        .iter()
@@ -321,6 +332,7 @@ pub fn collect_tests(test_data_dir: &Path, paths: &[&str]) -> Vec<(PathBuf, Stri
        .collect()
 }
+/// Collects paths to all `.rs` files from `dir` in a sorted `Vec<PathBuf>`.
 fn test_from_dir(dir: &Path) -> Vec<PathBuf> {
    let mut acc = Vec::new();
    for file in fs::read_dir(&dir).unwrap() {
@@ -334,6 +346,7 @@ fn test_from_dir(dir: &Path) -> Vec<PathBuf> {
    acc
 }
+/// Returns the path to the root directory of `rust-analyzer` project.
 pub fn project_dir() -> PathBuf {
    let dir = env!("CARGO_MANIFEST_DIR");
    PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
@@ -356,6 +369,9 @@ pub fn read_text(path: &Path) -> String {
        .replace("\r\n", "\n")
 }
+/// Returns `false` if slow tests should not run, otherwise returns `true` and
+/// also creates a file at `./target/.slow_tests_cookie` which serves as a flag
+/// that slow tests did run.
 pub fn skip_slow_tests() -> bool {
    let should_skip = std::env::var("CI").is_err() && std::env::var("RUN_SLOW_TESTS").is_err();
    if should_skip {
@@ -367,8 +383,9 @@ pub fn skip_slow_tests() -> bool {
    should_skip
 }
-const REWRITE: bool = false;
+/// Asserts that `expected` and `actual` strings are equal. If they differ only
+/// in trailing or leading whitespace the test won't fail and
+/// the contents of `actual` will be written to the file located at `path`.
 fn assert_equal_text(expected: &str, actual: &str, path: &Path) {
    if expected == actual {
        return;
@@ -381,6 +398,7 @@ fn assert_equal_text(expected: &str, actual: &str, path: &Path) {
        fs::write(path, actual).unwrap();
        return;
    }
+    const REWRITE: bool = false;
    if REWRITE {
        println!("rewriting {}", pretty_path.display());
        fs::write(path, actual).unwrap();
diff --git a/crates/test_utils/src/marks.rs b/crates/test_utils/src/marks.rs
index fe1813947..f8fabfaff 100644
--- a/crates/test_utils/src/marks.rs
+++ b/crates/test_utils/src/marks.rs
@@ -1,4 +1,4 @@
-//! This module implements manually tracked test coverage, which useful for
+//! This module implements manually tracked test coverage, which is useful for
 //! quickly finding a test responsible for testing a particular bit of code.
 //!
 //! See <https://matklad.github.io/2018/06/18/a-trick-for-test-maintenance.html>
diff --git a/docs/dev/README.md b/docs/dev/README.md
index 2f6215d6b..d30727786 100644
--- a/docs/dev/README.md
+++ b/docs/dev/README.md
@@ -26,15 +26,6 @@ Discussion happens in this Zulip stream:
 https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
-# Work List
-We have this "work list" paper document:
-https://paper.dropbox.com/doc/RLS-2.0-work-list--AZ3BgHKKCtqszbsi3gi6sjchAQ-42vbnxzuKq2lKwW0mkn8Y
-It shows what everyone is working on right now. If you want to (this is not
-mandatory), add yourself to the list!
 # Issue Labels
 * [good-first-issue](https://github.com/rust-analyzer/rust-analyzer/labels/good%20first%20issue)
@@ -50,10 +41,12 @@ mandatory), add yourself to the list!
 # CI
-We use Travis for CI. Most of the things, including formatting, are checked by
+We use GitHub Actions for CI. Most of the things, including formatting, are checked by
 `cargo test` so, if `cargo test` passes locally, that's a good sign that CI will
-be green as well. We use bors-ng to enforce the [not rocket
+be green as well. The only exception is that long-running by default a skipped locally.
-science](https://graydon2.dreamwidth.org/1597.html) rule.
+Use `env RUN_SLOW_TESTS=1 cargo test` to run the full suite.
+We use bors-ng to enforce the [not rocket science](https://graydon2.dreamwidth.org/1597.html) rule.
 You can run `cargo xtask install-pre-commit-hook` to install git-hook to run rustfmt on commit.
@@ -81,42 +74,41 @@ relevant test and execute it (VS Code includes an action for running a single
 test).
 However, launching a VS Code instance with locally build language server is
-possible. There's even a VS Code task for this, so just <kbd>F5</kbd> should
+possible. There's "Run Extension (Dev Server)" launch configuration for this.
-work (thanks, [@andrew-w-ross](https://github.com/andrew-w-ross)!).
+In general, I use one of the following workflows for fixing bugs and
-I often just install development version with `cargo xtask install --server --jemalloc` and
+implementing features.
-restart the host VS Code.
+If the problem concerns only internal parts of rust-analyzer (ie, I don't need
-See [./debugging.md](./debugging.md) for how to attach to rust-analyzer with
+to touch `ra_lsp_server` crate or typescript code), there is a unit-test for it.
-debugger, and don't forget that rust-analyzer has useful `pd` snippet and `dbg`
+So, I use **Rust Analyzer: Run** action in VS Code to run this single test, and
-postfix completion for printf debugging :-)
+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
-# Working With VS Code Extension
+Code to sanity check that the thing works as I expect.
-To work on the VS Code extension, launch code inside `editors/code` and use `F5`
+If the problem concerns only the VS Code extension, I use **Run Extension**
-to launch/debug. To automatically apply formatter and linter suggestions, use
+launch configuration from `launch.json`. Notably, this uses the usual
-`npm run fix`.
+`ra_lsp_server` binary from `PATH`. After I am done with the fix, I use `cargo
+xtask install --client-code` to try the new extension for real.
-Tests are located inside `src/test` and are named `*.test.ts`. They use the
-[Mocha](https://mochajs.org) test framework and the builtin Node
+If I need to fix something in the `ra_lsp_server` crate, I feel sad because it's
-[assert](https://nodejs.org/api/assert.html) module. Unlike normal Node tests
+on the boundary between the two processes, and working there is slow. I usually
-they must be hosted inside a VS Code instance. This can be done in one of two
+just `cargo xtask install --server` and poke changes from my live environment.
-ways:
+Note that this uses `--release`, which is usually faster overall, because
+loading stdlib into debug version of rust-analyzer takes a lot of time. To speed
-1. When `F5` debugging in VS Code select the `Extension Tests` configuration
+things up, sometimes I open a temporary hello-world project which has
-   from the drop-down at the top of the Debug View. This will launch a temporary
+`"rust-analyzer.withSysroot": false` in `.code/settings.json`. This flag causes
-   instance of VS Code. The test results will appear in the "Debug Console" tab
+rust-analyzer to skip loading the sysroot, which greatly reduces the amount of
-   of the primary VS Code instance.
+things rust-analyzer needs to do, and makes printf's more useful. Note that you
+should only use `eprint!` family of macros for debugging: stdout is used for LSP
-2. Run `npm test` from the command line. Although this is initiated from the
+communication, and `print!` would break it.
-   command line it is not headless; it will also launch a temporary instance of
-   VS Code.
+If I need to fix something simultaneously in the server and in the client, I
+feel even more sad. I don't have a specific workflow for this case.
-Due to the requirements of running the tests inside VS Code they are **not run
-on CI**. When making changes to the extension please ensure the tests are not
+Additionally, I use `cargo run --release -p ra_cli -- analysis-stats
-broken locally before opening a Pull Request.
+path/to/some/rust/crate` to run a batch analysis. This is primaraly useful for
+performance optimiations, or for bug minimization.
-To install **only** the VS Code extension, use `cargo xtask install --client-code`.
 # Logging
diff --git a/docs/dev/architecture.md b/docs/dev/architecture.md
index 629645757..9675ed0b6 100644
--- a/docs/dev/architecture.md
+++ b/docs/dev/architecture.md
@@ -12,6 +12,9 @@ analyzer:
 https://www.youtube.com/playlist?list=PL85XCvVPmGQho7MZkdW-wtPtuJcFpzycE
+Note that the guide and videos are pretty dated, this document should be in
+generally fresher.
 ## The Big Picture
 ![](https://user-images.githubusercontent.com/1711539/50114578-e8a34280-0255-11e9-902c-7cfc70747966.png)
@@ -20,13 +23,12 @@ On the highest level, rust-analyzer is a thing which accepts input source code
 from the client and produces a structured semantic model of the code.
 More specifically, input data consists of a set of test files (`(PathBuf,
-String)` pairs) and information about project structure, captured in the so called
+String)` pairs) and information about project structure, captured in the so
-`CrateGraph`. The crate graph specifies which files are crate roots, which cfg
+called `CrateGraph`. The crate graph specifies which files are crate roots,
-flags are specified for each crate (TODO: actually implement this) and what
+which cfg flags are specified for each crate and what dependencies exist between
-dependencies exist between the crates. The analyzer keeps all this input data in
+the crates. The analyzer keeps all this input data in memory and never does any
-memory and never does any IO. Because the input data is source code, which
+IO. Because the input data are source code, which typically measures in tens of
-typically measures in tens of megabytes at most, keeping all input data in
+megabytes at most, keeping everything in memory is OK.
-memory is OK.
 A "structured semantic model" is basically an object-oriented representation of
 modules, functions and types which appear in the source code. This representation
@@ -43,37 +45,39 @@ can be quickly updated for small modifications.
 ## Code generation
 Some of the components of this repository are generated through automatic
-processes. These are outlined below:
+processes. `cargo xtask codegen` runs all generation tasks. Generated code is
+commited to the git repository.
+In particular, `cargo xtask codegen` generates:
+1. [`syntax_kind/generated`](https://github.com/rust-analyzer/rust-analyzer/blob/a0be39296d2925972cacd9fbf8b5fb258fad6947/crates/ra_parser/src/syntax_kind/generated.rs)
+  -- the set of terminals and non-terminals of rust grammar.
- `cargo xtask codegen`: The kinds of tokens that are reused in several places, so a generator
+2. [`ast/generated`](https://github.com/rust-analyzer/rust-analyzer/blob/a0be39296d2925972cacd9fbf8b5fb258fad6947/crates/ra_syntax/src/ast/generated.rs)
-  is used. We use `quote!` macro to generate the files listed below, based on
+  -- AST data structure.
-  the grammar described in [grammar.ron]:
-  - [ast/generated.rs][ast generated]
-  - [syntax_kind/generated.rs][syntax_kind generated]
-[grammar.ron]: ../../crates/ra_syntax/src/grammar.ron
+.3 [`doc_tests/generated`](https://github.com/rust-analyzer/rust-analyzer/blob/a0be39296d2925972cacd9fbf8b5fb258fad6947/crates/ra_assists/src/doc_tests/generated.rs),
-[ast generated]: ../../crates/ra_syntax/src/ast/generated.rs
+  [`test_data/parser/inline`](https://github.com/rust-analyzer/rust-analyzer/tree/a0be39296d2925972cacd9fbf8b5fb258fad6947/crates/ra_syntax/test_data/parser/inline)
-[syntax_kind generated]: ../../crates/ra_parser/src/syntax_kind/generated.rs
+  -- tests for assists and the parser.
+The source for 1 and 2 is in [`ast_src.rs`](https://github.com/rust-analyzer/rust-analyzer/blob/a0be39296d2925972cacd9fbf8b5fb258fad6947/xtask/src/ast_src.rs).
 ## Code Walk-Through
 ### `crates/ra_syntax`, `crates/ra_parser`
 Rust syntax tree structure and parser. See
-[RFC](https://github.com/rust-lang/rfcs/pull/2256) for some design notes.
+[RFC](https://github.com/rust-lang/rfcs/pull/2256) and [./syntax.md](./syntax.md) for some design notes.
 - [rowan](https://github.com/rust-analyzer/rowan) library is used for constructing syntax trees.
 - `grammar` module is the actual parser. It is a hand-written recursive descent parser, which
  produces a sequence of events like "start node X", "finish node Y". It works similarly to [kotlin's parser](https://github.com/JetBrains/kotlin/blob/4d951de616b20feca92f3e9cc9679b2de9e65195/compiler/frontend/src/org/jetbrains/kotlin/parsing/KotlinParsing.java),
  which is a good source of inspiration for dealing with syntax errors and incomplete input. Original [libsyntax parser](https://github.com/rust-lang/rust/blob/6b99adeb11313197f409b4f7c4083c2ceca8a4fe/src/libsyntax/parse/parser.rs)
  is what we use for the definition of the Rust language.
- `parser_api/parser_impl` bridges the tree-agnostic parser from `grammar` with `rowan` trees.
+- `TreeSink` and `TokenSource` traits bridge the tree-agnostic parser from `grammar` with `rowan` trees.
-  This is the thing that turns a flat list of events into a tree (see `EventProcessor`)
 - `ast` provides a type safe API on top of the raw `rowan` tree.
- `grammar.ron` RON description of the grammar, which is used to
+- `ast_src` description of the grammar, which is used to generate `syntax_kinds`
-  generate `syntax_kinds` and `ast` modules, using `cargo xtask codegen` command.
+  and `ast` modules, using `cargo xtask codegen` command.
- `algo`: generic tree algorithms, including `walk` for O(1) stack
-  space tree traversal (this is cool).
 Tests for ra_syntax are mostly data-driven: `test_data/parser` contains subdirectories with a bunch of `.rs`
 (test vectors) and `.txt` files with corresponding syntax trees. During testing, we check
@@ -81,6 +85,10 @@ Tests for ra_syntax are mostly data-driven: `test_data/parser` contains subdirec
 tests). Additionally, running `cargo xtask codegen` will walk the grammar module and collect
 all `// test test_name` comments into files inside `test_data/parser/inline` directory.
+Note
+[`api_walkthrough`](https://github.com/rust-analyzer/rust-analyzer/blob/2fb6af89eb794f775de60b82afe56b6f986c2a40/crates/ra_syntax/src/lib.rs#L190-L348)
+in particular: it shows off various methods of working with syntax tree.
 See [#93](https://github.com/rust-analyzer/rust-analyzer/pull/93) for an example PR which
 fixes a bug in the grammar.
@@ -94,18 +102,22 @@ defines most of the "input" queries: facts supplied by the client of the
 analyzer. Reading the docs of the `ra_db::input` module should be useful:
 everything else is strictly derived from those inputs.
-### `crates/ra_hir`
+### `crates/ra_hir*` crates
 HIR provides high-level "object oriented" access to Rust code.
 The principal difference between HIR and syntax trees is that HIR is bound to a
-particular crate instance. That is, it has cfg flags and features applied (in
+particular crate instance. That is, it has cfg flags and features applied. So,
-theory, in practice this is to be implemented). So, the relation between
+the relation between syntax and HIR is many-to-one. The `source_binder` module
-syntax and HIR is many-to-one. The `source_binder` module is responsible for
+is responsible for guessing a HIR for a particular source position.
-guessing a HIR for a particular source position.
 Underneath, HIR works on top of salsa, using a `HirDatabase` trait.
+`ra_hir_xxx` crates have a strong ECS flavor, in that they work with raw ids and
+directly query the databse.
+The top-level `ra_hir` façade crate wraps ids into a more OO-flavored API.
 ### `crates/ra_ide`
 A stateful library for analyzing many Rust files as they change. `AnalysisHost`
@@ -135,18 +147,9 @@ different from data on disk. This is more or less the single really
 platform-dependent component, so it lives in a separate repository and has an
 extensive cross-platform CI testing.
-### `crates/gen_lsp_server`
-A language server scaffold, exposing a synchronous crossbeam-channel based API.
-This crate handles protocol handshaking and parsing messages, while you
-control the message dispatch loop yourself.
-Run with `RUST_LOG=sync_lsp_server=debug` to see all the messages.
 ### `crates/ra_cli`
-A CLI interface to rust-analyzer.
+A CLI interface to rust-analyzer, mainly for testing.
 ## Testing Infrastructure
diff --git a/docs/dev/debugging.md b/docs/dev/debugging.md
index f868e6998..1ccf4dca2 100644
--- a/docs/dev/debugging.md
+++ b/docs/dev/debugging.md
@@ -1,5 +1,7 @@
 # Debugging vs Code plugin and the Language Server
+**NOTE:** the information here is mostly obsolete
 Install [LLDB](https://lldb.llvm.org/) and the [LLDB Extension](https://marketplace.visualstudio.com/items?itemName=vadimcn.vscode-lldb).
 Checkout rust rust-analyzer and open it in vscode.
diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index d38a45b85..f92ce1fe2 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -25,9 +25,9 @@
            }
        },
        "@rollup/plugin-commonjs": {
-            "version": "11.0.0",
+            "version": "11.0.1",
-            "resolved": "https://registry.npmjs.org/@rollup/plugin-commonjs/-/plugin-commonjs-11.0.0.tgz",
+            "resolved": "https://registry.npmjs.org/@rollup/plugin-commonjs/-/plugin-commonjs-11.0.1.tgz",
-            "integrity": "sha512-jnm//T5ZWOZ6zmJ61fReSCBOif+Ax8dHVoVggA+d2NA7T4qCWgQ3KYr+zN2faGEYLpe1wa03IzvhR+sqVLxUWg==",
+            "integrity": "sha512-SaVUoaLDg3KnIXC5IBNIspr1APTYDzk05VaYcI6qz+0XX3ZlSCwAkfAhNSOxfd5GAdcm/63Noi4TowOY9MpcDg==",
            "dev": true,
            "requires": {
                "@rollup/pluginutils": "^3.0.0",
@@ -38,9 +38,9 @@
            }
        },
        "@rollup/plugin-node-resolve": {
-            "version": "6.0.0",
+            "version": "6.1.0",
-            "resolved": "https://registry.npmjs.org/@rollup/plugin-node-resolve/-/plugin-node-resolve-6.0.0.tgz",
+            "resolved": "https://registry.npmjs.org/@rollup/plugin-node-resolve/-/plugin-node-resolve-6.1.0.tgz",
-            "integrity": "sha512-GqWz1CfXOsqpeVMcoM315+O7zMxpRsmhWyhJoxLFHVSp9S64/u02i7len/FnbTNbmgYs+sZyilasijH8UiuboQ==",
+            "integrity": "sha512-Cv7PDIvxdE40SWilY5WgZpqfIUEaDxFxs89zCAHjqyRwlTSuql4M5hjIuc5QYJkOH0/vyiyNXKD72O+LhRipGA==",
            "dev": true,
            "requires": {
                "@rollup/pluginutils": "^3.0.0",
@@ -51,34 +51,42 @@
            }
        },
        "@rollup/plugin-typescript": {
-            "version": "2.0.1",
+            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/@rollup/plugin-typescript/-/plugin-typescript-2.0.1.tgz",
+            "resolved": "https://registry.npmjs.org/@rollup/plugin-typescript/-/plugin-typescript-2.1.0.tgz",
-            "integrity": "sha512-UA/bN/DlHN19xdOllXmp7G7pM2ac9dQMg0q2T1rg4Bogzb7oHXj2WGafpiNpEm54PivcJdzGRJvRnI6zCISW3w==",
+            "integrity": "sha512-7lXKGY06aofrceVez/YnN2axttFdHSqlUBpCJ6ebzDfxwLDKMgSV5lD4ykBcdgE7aK3egxuLkD/HKyRB5L8Log==",
            "dev": true,
            "requires": {
                "@rollup/pluginutils": "^3.0.0",
-                "resolve": "^1.12.2"
+                "resolve": "^1.13.1"
            }
        },
        "@rollup/pluginutils": {
-            "version": "3.0.1",
+            "version": "3.0.6",
-            "resolved": "https://registry.npmjs.org/@rollup/pluginutils/-/pluginutils-3.0.1.tgz",
+            "resolved": "https://registry.npmjs.org/@rollup/pluginutils/-/pluginutils-3.0.6.tgz",
-            "integrity": "sha512-PmNurkecagFimv7ZdKCVOfQuqKDPkrcpLFxRBcQ00LYr4HAjJwhCFxBiY2Xoletll2htTIiXBg6g0Yg21h2M3w==",
+            "integrity": "sha512-Nb6U7sg11v8D+E4mxRxwT+UumUL7MSnwI8V1SJB3THyW2MOGD/Q6GyxLtpnjrbT3zTRPSozzDMyVZwemgldO3w==",
            "dev": true,
            "requires": {
-                "estree-walker": "^0.6.1"
+                "estree-walker": "^1.0.1"
+            },
+            "dependencies": {
+                "estree-walker": {
+                    "version": "1.0.1",
+                    "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-1.0.1.tgz",
+                    "integrity": "sha512-1fMXF3YP4pZZVozF8j/ZLfvnR8NSIljt56UhbZ5PeeDmmGHpgpdwQt7ITlGvYaQukCvuBRMLEiKiYC+oeIg4cg==",
+                    "dev": true
+                }
            }
        },
        "@types/estree": {
-            "version": "0.0.41",
+            "version": "0.0.39",
-            "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.41.tgz",
+            "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.39.tgz",
-            "integrity": "sha512-rIAmXyJlqw4KEBO7+u9gxZZSQHaCNnIzYrnNmYVpgfJhxTqO0brCX0SYpqUTkVI5mwwUwzmtspLBGBKroMeynA==",
+            "integrity": "sha512-EYNwp3bU+98cpU4lAWYYL7Zz+2gryWH1qbdDTidVd6hkiR6weksdbMadyXKXNPEkQFhXM+hVO9ZygomHXp+AIw==",
            "dev": true
        },
        "@types/node": {
-            "version": "12.12.22",
+            "version": "12.12.25",
-            "resolved": "https://registry.npmjs.org/@types/node/-/node-12.12.22.tgz",
+            "resolved": "https://registry.npmjs.org/@types/node/-/node-12.12.25.tgz",
-            "integrity": "sha512-r5i93jqbPWGXYXxianGATOxTelkp6ih/U0WVnvaqAvTqM+0U6J3kw6Xk6uq/dWNRkEVw/0SLcO5ORXbVNz4FMQ==",
+            "integrity": "sha512-nf1LMGZvgFX186geVZR1xMZKKblJiRfiASTHw85zED2kI1yDKHDwTKMdkaCbTlXoRKlGKaDfYywt+V0As30q3w==",
            "dev": true
        },
        "@types/resolve": {
@@ -429,14 +437,6 @@
            "dev": true,
            "requires": {
                "@types/estree": "0.0.39"
-            },
-            "dependencies": {
-                "@types/estree": {
-                    "version": "0.0.39",
-                    "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.39.tgz",
-                    "integrity": "sha512-EYNwp3bU+98cpU4lAWYYL7Zz+2gryWH1qbdDTidVd6hkiR6weksdbMadyXKXNPEkQFhXM+hVO9ZygomHXp+AIw==",
-                    "dev": true
-                }
            }
        },
        "js-tokens": {
@@ -486,9 +486,9 @@
            }
        },
        "magic-string": {
-            "version": "0.25.4",
+            "version": "0.25.6",
-            "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.25.4.tgz",
+            "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.25.6.tgz",
-            "integrity": "sha512-oycWO9nEVAP2RVPbIoDoA4Y7LFIJ3xRYov93gAyJhZkET1tNuB0u7uWkZS2LpBWTJUWnmau/To8ECWRC+jKNfw==",
+            "integrity": "sha512-3a5LOMSGoCTH5rbqobC2HuDNRtE2glHZ8J7pK+QZYppyWA36yuNpsX994rIY2nCuyP7CZYy7lQq/X2jygiZ89g==",
            "dev": true,
            "requires": {
                "sourcemap-codec": "^1.4.4"
@@ -675,9 +675,9 @@
            }
        },
        "rollup": {
-            "version": "1.27.14",
+            "version": "1.30.1",
-            "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.27.14.tgz",
+            "resolved": "https://registry.npmjs.org/rollup/-/rollup-1.30.1.tgz",
-            "integrity": "sha512-DuDjEyn8Y79ALYXMt+nH/EI58L5pEw5HU9K38xXdRnxQhvzUTI/nxAawhkAHUQeudANQ//8iyrhVRHJBuR6DSQ==",
+            "integrity": "sha512-Uus8mwQXwaO+ZVoNwBcXKhT0AvycFCBW/W8VZtkpVGsotRllWk9oldfCjqWmTnFRI0y7x6BnEqSqc65N+/YdBw==",
            "dev": true,
            "requires": {
                "@types/estree": "*",
@@ -708,9 +708,9 @@
            "dev": true
        },
        "sourcemap-codec": {
-            "version": "1.4.6",
+            "version": "1.4.8",
-            "resolved": "https://registry.npmjs.org/sourcemap-codec/-/sourcemap-codec-1.4.6.tgz",
+            "resolved": "https://registry.npmjs.org/sourcemap-codec/-/sourcemap-codec-1.4.8.tgz",
-            "integrity": "sha512-1ZooVLYFxC448piVLBbtOxFcXwnymH9oUF8nRd3CuYDVvkRBxRl6pB4Mtas5a4drtL+E8LDgFkQNcgIw6tc8Hg==",
+            "integrity": "sha512-9NykojV5Uih4lgo5So5dtw+f0JgJX30KCNI8gwhz2J9A15wD0Ml6tjHKwf6fTSa6fAdVBdZeNOs9eJ71qCk8vA==",
            "dev": true
        },
        "sprintf-js": {
@@ -782,7 +782,7 @@
                "semver": {
                    "version": "5.7.1",
                    "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
-                    "integrity": "sha1-qVT5Ma66UI0we78Gnv8MAclhFvc=",
+                    "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
                    "dev": true
                }
            }
@@ -813,9 +813,9 @@
            }
        },
        "typescript": {
-            "version": "3.7.4",
+            "version": "3.7.5",
-            "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.7.4.tgz",
+            "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.7.5.tgz",
-            "integrity": "sha512-A25xv5XCtarLwXpcDNZzCGvW2D1S3/bACratYBx2sax8PefsFhlYmkQicKHvpYflFS8if4zne5zT5kpJ7pzuvw==",
+            "integrity": "sha512-/P5lkRXkWHNAbcJIiHPfRoKqyd7bsyCma1hZNUGfn20qm64T6ZBlrzprymeu918H+mB/0rIg2gGK/BXkhhYgBw==",
            "dev": true
        },
        "typescript-formatter": {
diff --git a/editors/code/package.json b/editors/code/package.json
index ce3de1e96..55d470fa0 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -28,16 +28,16 @@
        "vscode-languageclient": "^6.1.0"
    },
    "devDependencies": {
-        "@rollup/plugin-commonjs": "^11.0.0",
+        "@rollup/plugin-commonjs": "^11.0.1",
-        "@rollup/plugin-node-resolve": "^6.0.0",
+        "@rollup/plugin-node-resolve": "^6.1.0",
-        "@rollup/plugin-typescript": "^2.0.1",
+        "@rollup/plugin-typescript": "^2.1.0",
-        "@types/node": "^12.12.21",
+        "@types/node": "^12.12.25",
        "@types/seedrandom": "^2.4.28",
        "@types/vscode": "^1.41.0",
-        "rollup": "^1.27.14",
+        "rollup": "^1.30.1",
        "tslib": "^1.10.0",
        "tslint": "^5.20.1",
-        "typescript": "^3.7.3",
+        "typescript": "^3.7.5",
        "typescript-formatter": "^7.2.2",
        "vsce": "^1.71.0"
    },
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 1ff64a930..15e1a0873 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -15,7 +15,13 @@ export function createClient(config: Config): lc.LanguageClient {
    const command = expandPathResolving(config.raLspServerPath);
    if (spawnSync(command, ["--version"]).status !== 0) {
-        window.showErrorMessage(`Unable to execute '${command} --version'`);
+        window.showErrorMessage(
+            `Unable to execute '${command} --version'
+Perhaps it is not in $PATH?
+PATH=${process.env.PATH}
+`);
    }
    const run: lc.Executable = {
        command,