From a40e05dd5d8b2c5f74c61cd08efed9dc83124657 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 15 Jul 2020 14:37:44 +0200
Subject: [PATCH] Don't drop flycheck messages during restart

closes #5386
---
 crates/rust-analyzer/src/global_state.rs |  7 +++++-
 crates/rust-analyzer/src/main_loop.rs    |  8 +++---
 crates/rust-analyzer/src/reload.rs       | 32 +++++++++++-------------
 3 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index 9a9a6547a97..94973b90a49 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -63,7 +63,9 @@ pub(crate) struct GlobalState {
     req_queue: ReqQueue,
     pub(crate) task_pool: Handle<TaskPool<Task>, Receiver<Task>>,
     pub(crate) loader: Handle<Box<dyn vfs::loader::Handle>, Receiver<vfs::loader::Message>>,
-    pub(crate) flycheck: Option<Handle<FlycheckHandle, Receiver<flycheck::Message>>>,
+    pub(crate) flycheck: Option<FlycheckHandle>,
+    pub(crate) flycheck_sender: Sender<flycheck::Message>,
+    pub(crate) flycheck_receiver: Receiver<flycheck::Message>,
     pub(crate) config: Config,
     pub(crate) analysis_host: AnalysisHost,
     pub(crate) diagnostics: DiagnosticCollection,
@@ -103,12 +105,15 @@ pub(crate) fn new(sender: Sender<lsp_server::Message>, config: Config) -> Global
         };
 
         let analysis_host = AnalysisHost::new(config.lru_capacity);
+        let (flycheck_sender, flycheck_receiver) = unbounded();
         GlobalState {
             sender,
             req_queue: ReqQueue::default(),
             task_pool,
             loader,
             flycheck: None,
+            flycheck_sender,
+            flycheck_receiver,
             config,
             analysis_host,
             diagnostics: Default::default(),
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 5afcc2d87ac..a41f7f56466 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -5,7 +5,7 @@
     time::{Duration, Instant},
 };
 
-use crossbeam_channel::{never, select, Receiver};
+use crossbeam_channel::{select, Receiver};
 use lsp_server::{Connection, Notification, Request, Response};
 use lsp_types::notification::Notification as _;
 use ra_db::VfsPath;
@@ -108,7 +108,7 @@ fn next_event(&self, inbox: &Receiver<lsp_server::Message>) -> Option<Event> {
             recv(self.loader.receiver) -> task =>
                 Some(Event::Vfs(task.unwrap())),
 
-            recv(self.flycheck.as_ref().map_or(&never(), |it| &it.receiver)) -> task =>
+            recv(self.flycheck_receiver) -> task =>
                 Some(Event::Flycheck(task.unwrap())),
         }
     }
@@ -292,7 +292,7 @@ fn handle_event(&mut self, event: Event) -> Result<()> {
         let state_changed = self.process_changes();
         if prev_status == Status::Loading && self.status == Status::Ready {
             if let Some(flycheck) = &self.flycheck {
-                flycheck.handle.update();
+                flycheck.update();
             }
         }
 
@@ -441,7 +441,7 @@ fn on_notification(&mut self, not: Notification) -> Result<()> {
             })?
             .on::<lsp_types::notification::DidSaveTextDocument>(|this, params| {
                 if let Some(flycheck) = &this.flycheck {
-                    flycheck.handle.update();
+                    flycheck.update();
                 }
                 if let Ok(abs_path) = from_proto::abs_path(&params.text_document.uri) {
                     this.maybe_refresh(&[(abs_path, ChangeKind::Modify)]);
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index ab1b18ea97a..3f4dbdd8c3a 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -1,20 +1,19 @@
 //! Project loading & configuration updates
 use std::{mem, sync::Arc};
 
-use crossbeam_channel::unbounded;
 use flycheck::FlycheckHandle;
 use ra_db::{CrateGraph, SourceRoot, VfsPath};
 use ra_ide::AnalysisChange;
+use ra_prof::profile;
 use ra_project_model::{PackageRoot, ProcMacroClient, ProjectWorkspace};
 use vfs::{file_set::FileSetConfig, AbsPath, AbsPathBuf, ChangeKind};
 
 use crate::{
     config::{Config, FilesWatcher, LinkedProject},
-    global_state::{GlobalState, Handle, Status},
+    global_state::{GlobalState, Status},
     lsp_ext,
     main_loop::Task,
 };
-use ra_prof::profile;
 
 impl GlobalState {
     pub(crate) fn update_configuration(&mut self, config: Config) {
@@ -231,21 +230,20 @@ fn reload_flycheck(&mut self) {
             }
         };
 
-        // FIXME: Figure out the multi-workspace situation
-        self.flycheck = self.workspaces.iter().find_map(move |w| match w {
-            ProjectWorkspace::Cargo { cargo, .. } => {
-                let (sender, receiver) = unbounded();
-                let sender = Box::new(move |msg| sender.send(msg).unwrap());
+        let sender = self.flycheck_sender.clone();
+        let sender = Box::new(move |msg| sender.send(msg).unwrap());
+        self.flycheck = self
+            .workspaces
+            .iter()
+            // FIXME: Figure out the multi-workspace situation
+            .find_map(|w| match w {
+                ProjectWorkspace::Cargo { cargo, sysroot: _ } => Some(cargo),
+                ProjectWorkspace::Json { .. } => None,
+            })
+            .map(move |cargo| {
                 let cargo_project_root = cargo.workspace_root().to_path_buf();
-                let handle =
-                    FlycheckHandle::spawn(sender, config.clone(), cargo_project_root.into());
-                Some(Handle { handle, receiver })
-            }
-            ProjectWorkspace::Json { .. } => {
-                log::warn!("Cargo check watching only supported for cargo workspaces, disabling");
-                None
-            }
-        })
+                FlycheckHandle::spawn(sender, config.clone(), cargo_project_root.into())
+            })
     }
 }