6 files changed, 246 insertions, 116 deletions

diff --git a/crates/ra_lsp_server/Cargo.toml b/crates/ra_lsp_server/Cargo.toml
index 4ee3fb49f..fdf81ed87 100644
--- a/crates/ra_lsp_server/Cargo.toml
+++ b/crates/ra_lsp_server/Cargo.toml
@@ -26,10 +26,13 @@ lsp-server = "0.3.0"
 ra_project_model = { path = "../ra_project_model" }
 ra_prof = { path = "../ra_prof" }
 ra_vfs_glob = { path = "../ra_vfs_glob" }
-env_logger = { version = "0.7.1", default-features = false, features = ["humantime"] }
+env_logger = { version = "0.7.1", default-features = false }
 ra_cargo_watch = { path = "../ra_cargo_watch" }
 either = "1.5"
 
+[target.'cfg(windows)'.dependencies]
+winapi = "0.3"
+
 [dev-dependencies]
 tempfile = "3"
 test_utils = { path = "../test_utils" }
diff --git a/crates/ra_lsp_server/src/diagnostics.rs b/crates/ra_lsp_server/src/diagnostics.rs
new file mode 100644
index 000000000..ea08bce24
--- /dev/null
+++ b/crates/ra_lsp_server/src/diagnostics.rs
@@ -0,0 +1,85 @@
+//! Book keeping for keeping diagnostics easily in sync with the client.
+use lsp_types::{CodeActionOrCommand, Diagnostic, Range};
+use ra_ide::FileId;
+use std::{collections::HashMap, sync::Arc};
+
+pub type CheckFixes = Arc<HashMap<FileId, Vec<Fix>>>;
+
+#[derive(Debug, Default, Clone)]
+pub struct DiagnosticCollection {
+    pub native: HashMap<FileId, Vec<Diagnostic>>,
+    pub check: HashMap<FileId, Vec<Diagnostic>>,
+    pub check_fixes: CheckFixes,
+}
+
+#[derive(Debug, Clone)]
+pub struct Fix {
+    pub range: Range,
+    pub action: CodeActionOrCommand,
+}
+
+#[derive(Debug)]
+pub enum DiagnosticTask {
+    ClearCheck,
+    AddCheck(FileId, Diagnostic, Vec<CodeActionOrCommand>),
+    SetNative(FileId, Vec<Diagnostic>),
+}
+
+impl DiagnosticCollection {
+    pub fn clear_check(&mut self) -> Vec<FileId> {
+        Arc::make_mut(&mut self.check_fixes).clear();
+        self.check.drain().map(|(key, _value)| key).collect()
+    }
+
+    pub fn add_check_diagnostic(
+        &mut self,
+        file_id: FileId,
+        diagnostic: Diagnostic,
+        fixes: Vec<CodeActionOrCommand>,
+    ) {
+        let diagnostics = self.check.entry(file_id).or_default();
+        for existing_diagnostic in diagnostics.iter() {
+            if are_diagnostics_equal(&existing_diagnostic, &diagnostic) {
+                return;
+            }
+        }
+
+        let check_fixes = Arc::make_mut(&mut self.check_fixes);
+        check_fixes
+            .entry(file_id)
+            .or_default()
+            .extend(fixes.into_iter().map(|action| Fix { range: diagnostic.range, action }));
+        diagnostics.push(diagnostic);
+    }
+
+    pub fn set_native_diagnostics(&mut self, file_id: FileId, diagnostics: Vec<Diagnostic>) {
+        self.native.insert(file_id, diagnostics);
+    }
+
+    pub fn diagnostics_for(&self, file_id: FileId) -> impl Iterator<Item = &Diagnostic> {
+        let native = self.native.get(&file_id).into_iter().flatten();
+        let check = self.check.get(&file_id).into_iter().flatten();
+        native.chain(check)
+    }
+
+    pub fn handle_task(&mut self, task: DiagnosticTask) -> Vec<FileId> {
+        match task {
+            DiagnosticTask::ClearCheck => self.clear_check(),
+            DiagnosticTask::AddCheck(file_id, diagnostic, fixes) => {
+                self.add_check_diagnostic(file_id, diagnostic, fixes);
+                vec![file_id]
+            }
+            DiagnosticTask::SetNative(file_id, diagnostics) => {
+                self.set_native_diagnostics(file_id, diagnostics);
+                vec![file_id]
+            }
+        }
+    }
+}
+
+fn are_diagnostics_equal(left: &Diagnostic, right: &Diagnostic) -> bool {
+    left.source == right.source
+        && left.severity == right.severity
+        && left.range == right.range
+        && left.message == right.message
+}
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 2ca149fd5..1208c1343 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -29,6 +29,7 @@ mod markdown;
 pub mod req;
 mod config;
 mod world;
+mod diagnostics;
 
 pub type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
 pub use crate::{
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 7822be2e2..ceff82fda 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -5,21 +5,29 @@ 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 ra_cargo_watch::{CheckOptions, CheckTask};
+use lsp_types::{ClientCapabilities, NumberOrString};
+use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckTask};
 use ra_ide::{Canceled, FeatureFlags, FileId, LibraryData, SourceRootId};
 use ra_prof::profile;
-use ra_vfs::{VfsTask, Watch};
+use ra_vfs::{VfsFile, VfsTask, Watch};
 use relative_path::RelativePathBuf;
 use rustc_hash::FxHashSet;
 use serde::{de::DeserializeOwned, Serialize};
 use threadpool::ThreadPool;
 
 use crate::{
+    diagnostics::DiagnosticTask,
     main_loop::{
         pending_requests::{PendingRequest, PendingRequests},
         subscriptions::Subscriptions,
@@ -29,9 +37,6 @@ use crate::{
     Result, ServerConfig,
 };
 
-const THREADPOOL_SIZE: usize = 8;
-const MAX_IN_FLIGHT_LIBS: usize = THREADPOOL_SIZE - 3;
-
 #[derive(Debug)]
 pub struct LspError {
     pub code: i32,
@@ -60,6 +65,25 @@ pub fn main_loop(
 ) -> Result<()> {
     log::info!("server_config: {:#?}", config);
 
+    // Windows scheduler implements priority boosts: if thread waits for an
+    // event (like a condvar), and event fires, priority of the thread is
+    // temporary bumped. This optimization backfires in our case: each time the
+    // `main_loop` schedules a task to run on a threadpool, the worker threads
+    // gets a higher priority, and (on a machine with fewer cores) displaces the
+    // main loop! We work-around this by marking the main loop as a
+    // higher-priority thread.
+    //
+    // https://docs.microsoft.com/en-us/windows/win32/procthread/scheduling-priorities
+    // https://docs.microsoft.com/en-us/windows/win32/procthread/priority-boosts
+    // https://github.com/rust-analyzer/rust-analyzer/issues/2835
+    #[cfg(windows)]
+    unsafe {
+        use winapi::um::processthreadsapi::*;
+        let thread = GetCurrentThread();
+        let thread_priority_above_normal = 1;
+        SetThreadPriority(thread, thread_priority_above_normal);
+    }
+
     let mut loop_state = LoopState::default();
     let mut world_state = {
         let feature_flags = {
@@ -168,7 +192,7 @@ pub fn main_loop(
         )
     };
 
-    let pool = ThreadPool::new(THREADPOOL_SIZE);
+    let pool = ThreadPool::default();
     let (task_sender, task_receiver) = unbounded::<Task>();
     let (libdata_sender, libdata_receiver) = unbounded::<LibraryData>();
 
@@ -210,7 +234,7 @@ pub fn main_loop(
             )?;
         }
     }
-
+    world_state.analysis_host.request_cancellation();
     log::info!("waiting for tasks to finish...");
     task_receiver.into_iter().for_each(|task| {
         on_task(task, &connection.sender, &mut loop_state.pending_requests, &mut world_state)
@@ -231,6 +255,7 @@ pub fn main_loop(
 enum Task {
     Respond(Response),
     Notify(Notification),
+    Diagnostic(DiagnosticTask),
 }
 
 enum Event {
@@ -371,7 +396,8 @@ fn loop_turn(
         loop_state.pending_libraries.extend(changes);
     }
 
-    while loop_state.in_flight_libraries < MAX_IN_FLIGHT_LIBS
+    let max_in_flight_libs = pool.max_count().saturating_sub(2).max(1);
+    while loop_state.in_flight_libraries < max_in_flight_libs
         && !loop_state.pending_libraries.is_empty()
     {
         let (root, files) = loop_state.pending_libraries.pop().unwrap();
@@ -379,7 +405,6 @@ fn loop_turn(
         let sender = libdata_sender.clone();
         pool.execute(move || {
             log::info!("indexing {:?} ... ", root);
-            let _p = profile(&format!("indexed {:?}", root));
             let data = LibraryData::prepare(root, files);
             sender.send(data).unwrap();
         });
@@ -408,6 +433,19 @@ 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(())
 }
 
@@ -428,6 +466,7 @@ fn on_task(
         Task::Notify(n) => {
             msg_sender.send(n.into()).unwrap();
         }
+        Task::Diagnostic(task) => on_diagnostic_task(task, msg_sender, state),
     }
 }
 
@@ -435,7 +474,7 @@ 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,
@@ -444,7 +483,7 @@ fn on_request(
         req: Some(req),
         pool,
         world,
-        sender,
+        task_sender,
         msg_sender,
         pending_requests,
         request_received,
@@ -586,30 +625,26 @@ fn on_notification(
 
 fn on_check_task(
     task: CheckTask,
-    world_state: &WorldState,
+    world_state: &mut WorldState,
     task_sender: &Sender<Task>,
 ) -> Result<()> {
     match task {
         CheckTask::ClearDiagnostics => {
-            let cleared_files = world_state.check_watcher.state.write().clear();
-
-            // Send updated diagnostics for each cleared file
-            for url in cleared_files {
-                publish_diagnostics_for_url(&url, world_state, task_sender)?;
-            }
+            task_sender.send(Task::Diagnostic(DiagnosticTask::ClearCheck))?;
         }
 
-        CheckTask::AddDiagnostic(url, diagnostic) => {
-            world_state
-                .check_watcher
-                .state
-                .write()
-                .add_diagnostic_with_fixes(url.clone(), diagnostic);
-
-            // 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::AddDiagnostic { url, diagnostic, fixes } => {
+            let path = url.to_file_path().map_err(|()| format!("invalid uri: {}", url))?;
+            let file_id = match world_state.vfs.read().path2file(&path) {
+                Some(file) => FileId(file.0),
+                None => {
+                    log::error!("File with cargo diagnostic not found in VFS: {}", path.display());
+                    return Ok(());
+                }
+            };
+
+            task_sender
+                .send(Task::Diagnostic(DiagnosticTask::AddCheck(file_id, diagnostic, fixes)))?;
         }
 
         CheckTask::Status(progress) => {
@@ -620,22 +655,29 @@ fn on_check_task(
             let not = notification_new::<req::Progress>(params);
             task_sender.send(Task::Notify(not)).unwrap();
         }
-    }
+    };
+
     Ok(())
 }
 
-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))?;
+fn on_diagnostic_task(task: DiagnosticTask, msg_sender: &Sender<Message>, state: &mut WorldState) {
+    let subscriptions = state.diagnostics.handle_task(task);
+
+    for file_id in subscriptions {
+        let path = state.vfs.read().file2path(VfsFile(file_id.0));
+        let uri = match url_from_path_with_drive_lowercasing(&path) {
+            Ok(uri) => uri,
+            Err(err) => {
+                log::error!("Couldn't convert path to url ({}): {:?}", err, path.to_string_lossy());
+                continue;
+            }
+        };
+
+        let diagnostics = state.diagnostics.diagnostics_for(file_id).cloned().collect();
+        let params = req::PublishDiagnosticsParams { uri, diagnostics, version: None };
         let not = notification_new::<req::PublishDiagnostics>(params);
-        task_sender.send(Task::Notify(not)).unwrap();
+        msg_sender.send(not.into()).unwrap();
     }
-    Ok(())
 }
 
 struct PoolDispatcher<'a> {
@@ -644,7 +686,7 @@ 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,
 }
 
@@ -691,7 +733,7 @@ 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);
@@ -769,7 +811,7 @@ 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);
@@ -783,9 +825,8 @@ fn update_file_notifications_on_threadpool(
                             log::error!("failed to compute diagnostics: {:?}", e);
                         }
                     }
-                    Ok(params) => {
-                        let not = notification_new::<req::PublishDiagnostics>(params);
-                        sender.send(Task::Notify(not)).unwrap();
+                    Ok(task) => {
+                        task_sender.send(Task::Diagnostic(task)).unwrap();
                     }
                 }
             }
@@ -798,7 +839,7 @@ 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_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 8e43f0575..65e8bc856 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -1,17 +1,22 @@
 //! This module is responsible for implementing handlers for Lanuage Server Protocol.
 //! The majority of requests are fulfilled by calling into the `ra_ide` crate.
 
-use std::{fmt::Write as _, io::Write as _};
+use std::{
+    collections::hash_map::Entry,
+    fmt::Write as _,
+    io::Write as _,
+    process::{self, Stdio},
+};
 
-use either::Either;
 use lsp_server::ErrorCode;
 use lsp_types::{
     CallHierarchyIncomingCall, CallHierarchyIncomingCallsParams, CallHierarchyItem,
     CallHierarchyOutgoingCall, CallHierarchyOutgoingCallsParams, CallHierarchyPrepareParams,
-    CodeAction, CodeActionResponse, CodeLens, Command, CompletionItem, Diagnostic,
-    DocumentFormattingParams, DocumentHighlight, DocumentSymbol, FoldingRange, FoldingRangeParams,
-    Hover, HoverContents, Location, MarkupContent, MarkupKind, Position, PrepareRenameResponse,
-    Range, RenameParams, SymbolInformation, TextDocumentIdentifier, TextEdit, WorkspaceEdit,
+    CodeAction, CodeActionOrCommand, CodeActionResponse, CodeLens, Command, CompletionItem,
+    Diagnostic, DocumentFormattingParams, DocumentHighlight, DocumentSymbol, FoldingRange,
+    FoldingRangeParams, Hover, HoverContents, Location, MarkupContent, MarkupKind, Position,
+    PrepareRenameResponse, Range, RenameParams, SymbolInformation, TextDocumentIdentifier,
+    TextEdit, WorkspaceEdit,
 };
 use ra_ide::{
     AssistId, FileId, FilePosition, FileRange, Query, RangeInfo, Runnable, RunnableKind,
@@ -29,6 +34,7 @@ use crate::{
         to_call_hierarchy_item, to_location, Conv, ConvWith, FoldConvCtx, MapConvWith, TryConvWith,
         TryConvWithToVec,
     },
+    diagnostics::DiagnosticTask,
     req::{self, Decoration, InlayHint, InlayHintsParams, InlayKind},
     world::WorldSnapshot,
     LspError, Result,
@@ -582,21 +588,19 @@ pub fn handle_formatting(
     let file_line_index = world.analysis().file_line_index(file_id)?;
     let end_position = TextUnit::of_str(&file).conv_with(&file_line_index);
 
-    use std::process;
     let mut rustfmt = process::Command::new("rustfmt");
     if let Some(&crate_id) = crate_ids.first() {
         // Assume all crates are in the same edition
         let edition = world.analysis().crate_edition(crate_id)?;
         rustfmt.args(&["--edition", &edition.to_string()]);
     }
-    rustfmt.stdin(process::Stdio::piped()).stdout(process::Stdio::piped());
 
     if let Ok(path) = params.text_document.uri.to_file_path() {
         if let Some(parent) = path.parent() {
             rustfmt.current_dir(parent);
         }
     }
-    let mut rustfmt = rustfmt.spawn()?;
+    let mut rustfmt = rustfmt.stdin(Stdio::piped()).stdout(Stdio::piped()).spawn()?;
 
     rustfmt.stdin.as_mut().unwrap().write_all(file.as_bytes())?;
 
@@ -674,59 +678,61 @@ pub fn handle_code_action(
         res.push(action.into());
     }
 
-    for fix in world.check_watcher.read().fixes_for(&params.text_document.uri).into_iter().flatten()
-    {
-        let fix_range = fix.location.range.conv_with(&line_index);
+    for fix in world.check_fixes.get(&file_id).into_iter().flatten() {
+        let fix_range = fix.range.conv_with(&line_index);
         if fix_range.intersection(&range).is_none() {
             continue;
         }
+        res.push(fix.action.clone());
+    }
 
-        let edit = {
-            let edits = vec![TextEdit::new(fix.location.range, fix.replacement.clone())];
-            let mut edit_map = std::collections::HashMap::new();
-            edit_map.insert(fix.location.uri.clone(), edits);
-            WorkspaceEdit::new(edit_map)
+    let mut groups = FxHashMap::default();
+    for assist in world.analysis().assists(FileRange { file_id, range })?.into_iter() {
+        let arg = to_value(assist.source_change.try_conv_with(&world)?)?;
+
+        let (command, title, arg) = match assist.group_label {
+            None => ("rust-analyzer.applySourceChange", assist.label.clone(), arg),
+
+            // Group all assists with the same `group_label` into a single CodeAction.
+            Some(group_label) => {
+                match groups.entry(group_label.clone()) {
+                    Entry::Occupied(entry) => {
+                        let idx: usize = *entry.get();
+                        match &mut res[idx] {
+                            CodeActionOrCommand::CodeAction(CodeAction {
+                                command: Some(Command { arguments: Some(arguments), .. }),
+                                ..
+                            }) => match arguments.as_mut_slice() {
+                                [serde_json::Value::Array(arguments)] => arguments.push(arg),
+                                _ => panic!("invalid group"),
+                            },
+                            _ => panic!("invalid group"),
+                        }
+                        continue;
+                    }
+                    Entry::Vacant(entry) => {
+                        entry.insert(res.len());
+                    }
+                }
+                ("rust-analyzer.selectAndApplySourceChange", group_label, to_value(vec![arg])?)
+            }
         };
 
-        let action = CodeAction {
-            title: fix.title.clone(),
-            kind: Some("quickfix".to_string()),
-            diagnostics: Some(fix.diagnostics.clone()),
-            edit: Some(edit),
-            command: None,
-            is_preferred: None,
+        let command = Command {
+            title: assist.label.clone(),
+            command: command.to_string(),
+            arguments: Some(vec![arg]),
         };
-        res.push(action.into());
-    }
 
-    for assist in world.analysis().assists(FileRange { file_id, range })?.into_iter() {
-        let title = assist.label.clone();
-
-        let command = match assist.change_data {
-            Either::Left(change) => Command {
-                title,
-                command: "rust-analyzer.applySourceChange".to_string(),
-                arguments: Some(vec![to_value(change.try_conv_with(&world)?)?]),
-            },
-            Either::Right(changes) => Command {
-                title,
-                command: "rust-analyzer.selectAndApplySourceChange".to_string(),
-                arguments: Some(vec![to_value(
-                    changes
-                        .into_iter()
-                        .map(|change| change.try_conv_with(&world))
-                        .collect::<Result<Vec<_>>>()?,
-                )?]),
-            },
+        let kind = match assist.id {
+            AssistId("introduce_variable") => Some("refactor.extract.variable".to_string()),
+            AssistId("add_custom_impl") => Some("refactor.rewrite.add_custom_impl".to_string()),
+            _ => None,
         };
 
         let action = CodeAction {
-            title: command.title.clone(),
-            kind: match assist.id {
-                AssistId("introduce_variable") => Some("refactor.extract.variable".to_string()),
-                AssistId("add_custom_impl") => Some("refactor.rewrite.add_custom_impl".to_string()),
-                _ => None,
-            },
+            title,
+            kind,
             diagnostics: None,
             edit: None,
             command: Some(command),
@@ -874,14 +880,10 @@ pub fn handle_document_highlight(
     ))
 }
 
-pub fn publish_diagnostics(
-    world: &WorldSnapshot,
-    file_id: FileId,
-) -> Result<req::PublishDiagnosticsParams> {
+pub fn publish_diagnostics(world: &WorldSnapshot, file_id: FileId) -> Result<DiagnosticTask> {
     let _p = profile("publish_diagnostics");
-    let uri = world.file_id_to_uri(file_id)?;
     let line_index = world.analysis().file_line_index(file_id)?;
-    let mut diagnostics: Vec<Diagnostic> = world
+    let diagnostics: Vec<Diagnostic> = world
         .analysis()
         .diagnostics(file_id)?
         .into_iter()
@@ -895,10 +897,7 @@ pub fn publish_diagnostics(
             tags: None,
         })
         .collect();
-    if let Some(check_diags) = world.check_watcher.read().diagnostics_for(&uri) {
-        diagnostics.extend(check_diags.iter().cloned());
-    }
-    Ok(req::PublishDiagnosticsParams { uri, diagnostics, version: None })
+    Ok(DiagnosticTask::SetNative(file_id, diagnostics))
 }
 
 pub fn publish_decorations(
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index e7a0acfc7..1ee02b47c 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -12,9 +12,7 @@ use crossbeam_channel::{unbounded, Receiver};
 use lsp_server::ErrorCode;
 use lsp_types::Url;
 use parking_lot::RwLock;
-use ra_cargo_watch::{
-    url_from_path_with_drive_lowercasing, CheckOptions, CheckState, CheckWatcher,
-};
+use ra_cargo_watch::{url_from_path_with_drive_lowercasing, CheckOptions, CheckWatcher};
 use ra_ide::{
     Analysis, AnalysisChange, AnalysisHost, CrateGraph, FeatureFlags, FileId, LibraryData,
     SourceRootId,
@@ -25,6 +23,7 @@ use ra_vfs_glob::{Glob, RustPackageFilterBuilder};
 use relative_path::RelativePathBuf;
 
 use crate::{
+    diagnostics::{CheckFixes, DiagnosticCollection},
     main_loop::pending_requests::{CompletedRequest, LatestRequests},
     LspError, Result,
 };
@@ -55,6 +54,7 @@ pub struct WorldState {
     pub task_receiver: Receiver<VfsTask>,
     pub latest_requests: Arc<RwLock<LatestRequests>>,
     pub check_watcher: CheckWatcher,
+    pub diagnostics: DiagnosticCollection,
 }
 
 /// An immutable snapshot of the world's state at a point in time.
@@ -63,7 +63,7 @@ pub struct WorldSnapshot {
     pub workspaces: Arc<Vec<ProjectWorkspace>>,
     pub analysis: Analysis,
     pub latest_requests: Arc<RwLock<LatestRequests>>,
-    pub check_watcher: Arc<RwLock<CheckState>>,
+    pub check_fixes: CheckFixes,
     vfs: Arc<RwLock<Vfs>>,
 }
 
@@ -159,6 +159,7 @@ impl WorldState {
             task_receiver,
             latest_requests: Default::default(),
             check_watcher,
+            diagnostics: Default::default(),
         }
     }
 
@@ -220,7 +221,7 @@ impl WorldState {
             analysis: self.analysis_host.analysis(),
             vfs: Arc::clone(&self.vfs),
             latest_requests: Arc::clone(&self.latest_requests),
-            check_watcher: self.check_watcher.state.clone(),
+            check_fixes: Arc::clone(&self.diagnostics.check_fixes),
         }
     }