Merge #5068

5068: Prep dynamic reload r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <[email protected]>

7 files changed, 309 insertions, 289 deletions

diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index c5cf5ff27..b1250f2fe 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -9,7 +9,7 @@ use ra_ide::{AnalysisChange, AnalysisHost};
 use ra_project_model::{CargoConfig, ProcMacroClient, ProjectManifest, ProjectWorkspace};
 use vfs::{loader::Handle, AbsPath};
 
-use crate::global_state::{ProjectFolders, SourceRootConfig};
+use crate::reload::{ProjectFolders, SourceRootConfig};
 
 pub fn load_cargo(
     root: &Path,
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 435bbbb6b..6b17ce18b 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -30,7 +30,7 @@ pub struct Config {
 
     pub cargo: CargoConfig,
     pub rustfmt: RustfmtConfig,
-    pub check: Option<FlycheckConfig>,
+    pub flycheck: Option<FlycheckConfig>,
 
     pub inlay_hints: InlayHintsConfig,
     pub completion: CompletionConfig,
@@ -147,7 +147,7 @@ impl Config {
 
             cargo: CargoConfig::default(),
             rustfmt: RustfmtConfig::Rustfmt { extra_args: Vec::new() },
-            check: Some(FlycheckConfig::CargoCommand {
+            flycheck: Some(FlycheckConfig::CargoCommand {
                 command: "check".to_string(),
                 all_targets: true,
                 all_features: false,
@@ -227,14 +227,14 @@ impl Config {
 
         if let Some(false) = get(value, "/checkOnSave/enable") {
             // check is disabled
-            self.check = None;
+            self.flycheck = None;
         } else {
             // check is enabled
             match get::<Vec<String>>(value, "/checkOnSave/overrideCommand") {
                 // first see if the user has completely overridden the command
                 Some(mut args) if !args.is_empty() => {
                     let command = args.remove(0);
-                    self.check = Some(FlycheckConfig::CustomCommand {
+                    self.flycheck = Some(FlycheckConfig::CustomCommand {
                         command,
                         args,
                     });
@@ -242,7 +242,7 @@ impl Config {
                 // otherwise configure command customizations
                 _ => {
                     if let Some(FlycheckConfig::CargoCommand { command, extra_args, all_targets, all_features, features })
-                        = &mut self.check
+                        = &mut self.flycheck
                     {
                         set(value, "/checkOnSave/extraArgs", extra_args);
                         set(value, "/checkOnSave/command", command);
diff --git a/crates/rust-analyzer/src/dispatch.rs b/crates/rust-analyzer/src/dispatch.rs
index 03b373dee..891fdb96d 100644
--- a/crates/rust-analyzer/src/dispatch.rs
+++ b/crates/rust-analyzer/src/dispatch.rs
@@ -59,7 +59,7 @@ impl<'a> RequestDispatcher<'a> {
             }
         };
 
-        self.global_state.task_pool.0.spawn({
+        self.global_state.task_pool.handle.spawn({
             let world = self.global_state.snapshot();
             move || {
                 let result = f(world, params);
diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index 149b1b5f9..17de2a075 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -3,24 +3,25 @@
 //!
 //! Each tick provides an immutable snapshot of the state as `WorldSnapshot`.
 
-use std::{convert::TryFrom, sync::Arc};
+use std::sync::Arc;
 
 use crossbeam_channel::{unbounded, Receiver, Sender};
-use flycheck::{FlycheckConfig, FlycheckHandle};
+use flycheck::FlycheckHandle;
 use lsp_types::Url;
 use parking_lot::RwLock;
-use ra_db::{CrateId, SourceRoot, VfsPath};
-use ra_ide::{Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId};
+use ra_db::{CrateId, VfsPath};
+use ra_ide::{Analysis, AnalysisChange, AnalysisHost, FileId};
 use ra_project_model::{CargoWorkspace, ProcMacroClient, ProjectWorkspace, Target};
 use stdx::format_to;
-use vfs::{file_set::FileSetConfig, loader::Handle, AbsPath, AbsPathBuf};
+use vfs::loader::Handle as _;
 
 use crate::{
-    config::{Config, FilesWatcher},
+    config::Config,
     diagnostics::{CheckFixes, DiagnosticCollection},
     from_proto,
     line_endings::LineEndings,
     main_loop::{ReqQueue, Task},
+    reload::SourceRootConfig,
     request_metrics::{LatestRequests, RequestMetrics},
     show_message,
     thread_pool::TaskPool,
@@ -29,26 +30,6 @@ use crate::{
 };
 use rustc_hash::{FxHashMap, FxHashSet};
 
-fn create_flycheck(
-    workspaces: &[ProjectWorkspace],
-    config: &FlycheckConfig,
-) -> Option<(FlycheckHandle, Receiver<flycheck::Message>)> {
-    // FIXME: Figure out the multi-workspace situation
-    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 cargo_project_root = cargo.workspace_root().to_path_buf();
-            let flycheck = FlycheckHandle::spawn(sender, config.clone(), cargo_project_root.into());
-            Some((flycheck, receiver))
-        }
-        ProjectWorkspace::Json { .. } => {
-            log::warn!("Cargo check watching only supported for cargo workspaces, disabling");
-            None
-        }
-    })
-}
-
 #[derive(Eq, PartialEq)]
 pub(crate) enum Status {
     Loading,
@@ -61,28 +42,35 @@ impl Default for Status {
     }
 }
 
+// Enforces drop order
+pub(crate) struct Handle<H, C> {
+    pub(crate) handle: H,
+    pub(crate) receiver: C,
+}
+
 /// `GlobalState` is the primary mutable state of the language server
 ///
 /// The most interesting components are `vfs`, which stores a consistent
 /// snapshot of the file systems, and `analysis_host`, which stores our
 /// incremental salsa database.
+///
+/// Note that this struct has more than on impl in various modules!
 pub(crate) struct GlobalState {
     sender: Sender<lsp_server::Message>,
+    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) config: Config,
-    pub(crate) task_pool: (TaskPool<Task>, Receiver<Task>),
     pub(crate) analysis_host: AnalysisHost,
-    pub(crate) loader: Box<dyn vfs::loader::Handle>,
-    pub(crate) task_receiver: Receiver<vfs::loader::Message>,
-    pub(crate) flycheck: Option<(FlycheckHandle, Receiver<flycheck::Message>)>,
     pub(crate) diagnostics: DiagnosticCollection,
     pub(crate) mem_docs: FxHashSet<VfsPath>,
     pub(crate) vfs: Arc<RwLock<(vfs::Vfs, FxHashMap<FileId, LineEndings>)>>,
     pub(crate) status: Status,
     pub(crate) req_queue: ReqQueue,
+    pub(crate) source_root_config: SourceRootConfig,
+    pub(crate) proc_macro_client: ProcMacroClient,
+    pub(crate) workspaces: Arc<Vec<ProjectWorkspace>>,
     latest_requests: Arc<RwLock<LatestRequests>>,
-    source_root_config: SourceRootConfig,
-    _proc_macro_client: ProcMacroClient,
-    workspaces: Arc<Vec<ProjectWorkspace>>,
 }
 
 /// An immutable snapshot of the world's state at a point in time.
@@ -98,102 +86,40 @@ pub(crate) struct GlobalStateSnapshot {
 impl GlobalState {
     pub(crate) fn new(
         sender: Sender<lsp_server::Message>,
-        workspaces: Vec<ProjectWorkspace>,
         lru_capacity: Option<usize>,
         config: Config,
-        req_queue: ReqQueue,
     ) -> GlobalState {
-        let mut change = AnalysisChange::new();
-
-        let project_folders = ProjectFolders::new(&workspaces);
-
-        let (task_sender, task_receiver) = unbounded::<vfs::loader::Message>();
-        let mut vfs = vfs::Vfs::default();
-
-        let proc_macro_client = match &config.proc_macro_srv {
-            None => ProcMacroClient::dummy(),
-            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
-                Ok(it) => it,
-                Err(err) => {
-                    log::error!(
-                        "Failed to run ra_proc_macro_srv from path {}, error: {:?}",
-                        path.display(),
-                        err
-                    );
-                    ProcMacroClient::dummy()
-                }
-            },
+        let loader = {
+            let (sender, receiver) = unbounded::<vfs::loader::Message>();
+            let handle =
+                vfs_notify::NotifyHandle::spawn(Box::new(move |msg| sender.send(msg).unwrap()));
+            let handle = Box::new(handle) as Box<dyn vfs::loader::Handle>;
+            Handle { handle, receiver }
         };
 
-        let mut loader = {
-            let loader = vfs_notify::NotifyHandle::spawn(Box::new(move |msg| {
-                task_sender.send(msg).unwrap()
-            }));
-            Box::new(loader)
-        };
-        let watch = match config.files.watcher {
-            FilesWatcher::Client => vec![],
-            FilesWatcher::Notify => project_folders.watch,
-        };
-        loader.set_config(vfs::loader::Config { load: project_folders.load, watch });
-
-        // Create crate graph from all the workspaces
-        let mut crate_graph = CrateGraph::default();
-        let mut load = |path: &AbsPath| {
-            let contents = loader.load_sync(path);
-            let path = vfs::VfsPath::from(path.to_path_buf());
-            vfs.set_file_contents(path.clone(), contents);
-            vfs.file_id(&path)
-        };
-        for ws in workspaces.iter() {
-            crate_graph.extend(ws.to_crate_graph(
-                config.cargo.target.as_deref(),
-                &proc_macro_client,
-                &mut load,
-            ));
-        }
-        change.set_crate_graph(crate_graph);
-
-        let flycheck = config.check.as_ref().and_then(|c| create_flycheck(&workspaces, c));
-
-        let mut analysis_host = AnalysisHost::new(lru_capacity);
-        analysis_host.apply_change(change);
-
         let task_pool = {
             let (sender, receiver) = unbounded();
-            (TaskPool::new(sender), receiver)
+            let handle = TaskPool::new(sender);
+            Handle { handle, receiver }
         };
 
-        let mut res = GlobalState {
+        GlobalState {
             sender,
-            config,
             task_pool,
-            analysis_host,
             loader,
-            task_receiver,
-            flycheck,
+            config,
+            analysis_host: AnalysisHost::new(lru_capacity),
+            flycheck: None,
             diagnostics: Default::default(),
             mem_docs: FxHashSet::default(),
-            vfs: Arc::new(RwLock::new((vfs, FxHashMap::default()))),
+            vfs: Arc::new(RwLock::new((vfs::Vfs::default(), FxHashMap::default()))),
             status: Status::default(),
-            req_queue,
+            req_queue: ReqQueue::default(),
+            source_root_config: SourceRootConfig::default(),
+            proc_macro_client: ProcMacroClient::dummy(),
+            workspaces: Arc::new(Vec::new()),
             latest_requests: Default::default(),
-            source_root_config: project_folders.source_root_config,
-            _proc_macro_client: proc_macro_client,
-            workspaces: Arc::new(workspaces),
-        };
-        res.process_changes();
-        res
-    }
-
-    pub(crate) fn update_configuration(&mut self, config: Config) {
-        self.analysis_host.update_lru_capacity(config.lru_capacity);
-        if config.check != self.config.check {
-            self.flycheck =
-                config.check.as_ref().and_then(|it| create_flycheck(&self.workspaces, it));
         }
-
-        self.config = config;
     }
 
     pub(crate) fn process_changes(&mut self) -> bool {
@@ -266,7 +192,7 @@ impl GlobalState {
             self.send(response.into());
         }
     }
-    pub(crate) fn show_message(&mut self, typ: lsp_types::MessageType, message: String) {
+    pub(crate) fn show_message(&self, typ: lsp_types::MessageType, message: String) {
         show_message(typ, message, &self.sender)
     }
 }
@@ -343,78 +269,3 @@ pub(crate) fn file_id_to_url(vfs: &vfs::Vfs, id: FileId) -> Url {
     let path = path.as_path().unwrap();
     url_from_abs_path(&path)
 }
-
-#[derive(Default)]
-pub(crate) struct ProjectFolders {
-    pub(crate) load: Vec<vfs::loader::Entry>,
-    pub(crate) watch: Vec<usize>,
-    pub(crate) source_root_config: SourceRootConfig,
-}
-
-impl ProjectFolders {
-    pub(crate) fn new(workspaces: &[ProjectWorkspace]) -> ProjectFolders {
-        let mut res = ProjectFolders::default();
-        let mut fsc = FileSetConfig::builder();
-        let mut local_filesets = vec![];
-
-        for root in workspaces.iter().flat_map(|it| it.to_roots()) {
-            let path = root.path().to_owned();
-
-            let mut file_set_roots: Vec<VfsPath> = vec![];
-
-            let entry = if root.is_member() {
-                vfs::loader::Entry::local_cargo_package(path.to_path_buf())
-            } else {
-                vfs::loader::Entry::cargo_package_dependency(path.to_path_buf())
-            };
-            res.load.push(entry);
-            if root.is_member() {
-                res.watch.push(res.load.len() - 1);
-            }
-
-            if let Some(out_dir) = root.out_dir() {
-                let out_dir = AbsPathBuf::try_from(out_dir.to_path_buf()).unwrap();
-                res.load.push(vfs::loader::Entry::rs_files_recursively(out_dir.clone()));
-                if root.is_member() {
-                    res.watch.push(res.load.len() - 1);
-                }
-                file_set_roots.push(out_dir.into());
-            }
-            file_set_roots.push(path.to_path_buf().into());
-
-            if root.is_member() {
-                local_filesets.push(fsc.len());
-            }
-            fsc.add_file_set(file_set_roots)
-        }
-
-        let fsc = fsc.build();
-        res.source_root_config = SourceRootConfig { fsc, local_filesets };
-
-        res
-    }
-}
-
-#[derive(Default, Debug)]
-pub(crate) struct SourceRootConfig {
-    pub(crate) fsc: FileSetConfig,
-    pub(crate) local_filesets: Vec<usize>,
-}
-
-impl SourceRootConfig {
-    pub(crate) fn partition(&self, vfs: &vfs::Vfs) -> Vec<SourceRoot> {
-        self.fsc
-            .partition(vfs)
-            .into_iter()
-            .enumerate()
-            .map(|(idx, file_set)| {
-                let is_local = self.local_filesets.contains(&idx);
-                if is_local {
-                    SourceRoot::new_local(file_set)
-                } else {
-                    SourceRoot::new_library(file_set)
-                }
-            })
-            .collect()
-    }
-}
diff --git a/crates/rust-analyzer/src/lib.rs b/crates/rust-analyzer/src/lib.rs
index d503fe96e..a24dfe58c 100644
--- a/crates/rust-analyzer/src/lib.rs
+++ b/crates/rust-analyzer/src/lib.rs
@@ -18,6 +18,7 @@ macro_rules! eprintln {
 }
 
 mod global_state;
+mod reload;
 mod main_loop;
 mod dispatch;
 mod handlers;
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 1bd9d6389..d4879283d 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -11,17 +11,14 @@ use lsp_types::{notification::Notification as _, request::Request as _};
 use ra_db::VfsPath;
 use ra_ide::{Canceled, FileId};
 use ra_prof::profile;
-use ra_project_model::{PackageRoot, ProjectWorkspace};
 
 use crate::{
-    config::{Config, FilesWatcher, LinkedProject},
+    config::Config,
     dispatch::{NotificationDispatcher, RequestDispatcher},
     from_proto,
     global_state::{file_id_to_url, GlobalState, Status},
     handlers, lsp_ext,
-    lsp_utils::{
-        apply_document_changes, is_canceled, notification_is, notification_new, show_message,
-    },
+    lsp_utils::{apply_document_changes, is_canceled, notification_is, notification_new},
     Result,
 };
 
@@ -47,81 +44,8 @@ pub fn main_loop(config: Config, connection: Connection) -> Result<()> {
         SetThreadPriority(thread, thread_priority_above_normal);
     }
 
-    let global_state = {
-        let workspaces = {
-            if config.linked_projects.is_empty() && config.notifications.cargo_toml_not_found {
-                show_message(
-                    lsp_types::MessageType::Error,
-                    "rust-analyzer failed to discover workspace".to_string(),
-                    &connection.sender,
-                );
-            };
-
-            config
-                .linked_projects
-                .iter()
-                .filter_map(|project| match project {
-                    LinkedProject::ProjectManifest(manifest) => {
-                        ra_project_model::ProjectWorkspace::load(
-                            manifest.clone(),
-                            &config.cargo,
-                            config.with_sysroot,
-                        )
-                        .map_err(|err| {
-                            log::error!("failed to load workspace: {:#}", err);
-                            show_message(
-                                lsp_types::MessageType::Error,
-                                format!("rust-analyzer failed to load workspace: {:#}", err),
-                                &connection.sender,
-                            );
-                        })
-                        .ok()
-                    }
-                    LinkedProject::InlineJsonProject(it) => {
-                        Some(ra_project_model::ProjectWorkspace::Json { project: it.clone() })
-                    }
-                })
-                .collect::<Vec<_>>()
-        };
-
-        let mut req_queue = ReqQueue::default();
-
-        if let FilesWatcher::Client = config.files.watcher {
-            let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
-                watchers: workspaces
-                    .iter()
-                    .flat_map(ProjectWorkspace::to_roots)
-                    .filter(PackageRoot::is_member)
-                    .map(|root| format!("{}/**/*.rs", root.path().display()))
-                    .map(|glob_pattern| lsp_types::FileSystemWatcher { glob_pattern, kind: None })
-                    .collect(),
-            };
-            let registration = lsp_types::Registration {
-                id: "file-watcher".to_string(),
-                method: "workspace/didChangeWatchedFiles".to_string(),
-                register_options: Some(serde_json::to_value(registration_options).unwrap()),
-            };
-            let params = lsp_types::RegistrationParams { registrations: vec![registration] };
-            let request = req_queue.outgoing.register(
-                lsp_types::request::RegisterCapability::METHOD.to_string(),
-                params,
-                DO_NOTHING,
-            );
-            connection.sender.send(request.into()).unwrap();
-        }
-
-        GlobalState::new(
-            connection.sender.clone(),
-            workspaces,
-            config.lru_capacity,
-            config,
-            req_queue,
-        )
-    };
-
-    log::info!("server initialized, serving requests");
-    global_state.run(connection.receiver)?;
-    Ok(())
+    GlobalState::new(connection.sender.clone(), config.lru_capacity, config)
+        .run(connection.receiver)
 }
 
 enum Event {
@@ -176,36 +100,39 @@ impl GlobalState {
             recv(inbox) -> msg =>
                 msg.ok().map(Event::Lsp),
 
-            recv(self.task_pool.1) -> task =>
+            recv(self.task_pool.receiver) -> task =>
                 Some(Event::Task(task.unwrap())),
 
-            recv(self.task_receiver) -> task =>
+            recv(self.loader.receiver) -> task =>
                 Some(Event::Vfs(task.unwrap())),
 
-            recv(self.flycheck.as_ref().map_or(&never(), |it| &it.1)) -> task =>
+            recv(self.flycheck.as_ref().map_or(&never(), |it| &it.receiver)) -> task =>
                 Some(Event::Flycheck(task.unwrap())),
         }
     }
 
     fn run(mut self, inbox: Receiver<lsp_server::Message>) -> Result<()> {
+        self.reload();
+
         while let Some(event) = self.next_event(&inbox) {
             if let Event::Lsp(lsp_server::Message::Notification(not)) = &event {
                 if not.method == lsp_types::notification::Exit::METHOD {
                     return Ok(());
                 }
             }
-            self.loop_turn(event)?
+            self.handle_event(event)?
         }
+
         Err("client exited without proper shutdown sequence")?
     }
 
-    fn loop_turn(&mut self, event: Event) -> Result<()> {
+    fn handle_event(&mut self, event: Event) -> Result<()> {
         let loop_start = Instant::now();
         // NOTE: don't count blocking select! call as a loop-turn time
-        let _p = profile("main_loop_inner/loop-turn");
+        let _p = profile("GlobalState::handle_event");
 
-        log::info!("loop turn = {:?}", event);
-        let queue_count = self.task_pool.0.len();
+        log::info!("handle_event({:?})", event);
+        let queue_count = self.task_pool.handle.len();
         if queue_count > 0 {
             log::info!("queued count = {}", queue_count);
         }
@@ -306,7 +233,7 @@ impl GlobalState {
         let state_changed = self.process_changes();
         if became_ready {
             if let Some(flycheck) = &self.flycheck {
-                flycheck.0.update();
+                flycheck.handle.update();
             }
         }
 
@@ -443,7 +370,7 @@ impl GlobalState {
                         log::error!("orphan DidCloseTextDocument: {}", path)
                     }
                     if let Some(path) = path.as_path() {
-                        this.loader.invalidate(path.to_path_buf());
+                        this.loader.handle.invalidate(path.to_path_buf());
                     }
                 }
                 let params = lsp_types::PublishDiagnosticsParams {
@@ -457,7 +384,7 @@ impl GlobalState {
             })?
             .on::<lsp_types::notification::DidSaveTextDocument>(|this, _params| {
                 if let Some(flycheck) = &this.flycheck {
-                    flycheck.0.update();
+                    flycheck.handle.update();
                 }
                 Ok(())
             })?
@@ -500,7 +427,7 @@ impl GlobalState {
             .on::<lsp_types::notification::DidChangeWatchedFiles>(|this, params| {
                 for change in params.changes {
                     if let Ok(path) = from_proto::abs_path(&change.uri) {
-                        this.loader.invalidate(path);
+                        this.loader.handle.invalidate(path);
                     }
                 }
                 Ok(())
@@ -513,7 +440,7 @@ impl GlobalState {
         if self.config.publish_diagnostics {
             let snapshot = self.snapshot();
             let subscriptions = subscriptions.clone();
-            self.task_pool.0.spawn(move || {
+            self.task_pool.handle.spawn(move || {
                 let diagnostics = subscriptions
                     .into_iter()
                     .filter_map(|file_id| {
@@ -531,7 +458,7 @@ impl GlobalState {
                 Task::Diagnostics(diagnostics)
             })
         }
-        self.task_pool.0.spawn({
+        self.task_pool.handle.spawn({
             let subs = subscriptions;
             let snap = self.snapshot();
             move || {
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
new file mode 100644
index 000000000..a22d3e262
--- /dev/null
+++ b/crates/rust-analyzer/src/reload.rs
@@ -0,0 +1,241 @@
+//! Project loading & configuration updates
+use std::sync::Arc;
+
+use crossbeam_channel::unbounded;
+use flycheck::FlycheckHandle;
+use lsp_types::request::Request;
+use ra_db::{CrateGraph, SourceRoot, VfsPath};
+use ra_ide::AnalysisChange;
+use ra_project_model::{PackageRoot, ProcMacroClient, ProjectWorkspace};
+use vfs::{file_set::FileSetConfig, AbsPath};
+
+use crate::{
+    config::{Config, FilesWatcher, LinkedProject},
+    global_state::{GlobalState, Handle},
+};
+
+impl GlobalState {
+    pub(crate) fn update_configuration(&mut self, new_config: Config) {
+        self.analysis_host.update_lru_capacity(new_config.lru_capacity);
+        if new_config.flycheck != self.config.flycheck {
+            self.reload_flycheck();
+        }
+        self.config = new_config;
+    }
+    pub(crate) fn reload(&mut self) {
+        let workspaces = {
+            if self.config.linked_projects.is_empty()
+                && self.config.notifications.cargo_toml_not_found
+            {
+                self.show_message(
+                    lsp_types::MessageType::Error,
+                    "rust-analyzer failed to discover workspace".to_string(),
+                );
+            };
+
+            self.config
+                .linked_projects
+                .iter()
+                .filter_map(|project| match project {
+                    LinkedProject::ProjectManifest(manifest) => {
+                        ra_project_model::ProjectWorkspace::load(
+                            manifest.clone(),
+                            &self.config.cargo,
+                            self.config.with_sysroot,
+                        )
+                        .map_err(|err| {
+                            log::error!("failed to load workspace: {:#}", err);
+                            self.show_message(
+                                lsp_types::MessageType::Error,
+                                format!("rust-analyzer failed to load workspace: {:#}", err),
+                            );
+                        })
+                        .ok()
+                    }
+                    LinkedProject::InlineJsonProject(it) => {
+                        Some(ra_project_model::ProjectWorkspace::Json { project: it.clone() })
+                    }
+                })
+                .collect::<Vec<_>>()
+        };
+
+        if let FilesWatcher::Client = self.config.files.watcher {
+            let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
+                watchers: workspaces
+                    .iter()
+                    .flat_map(ProjectWorkspace::to_roots)
+                    .filter(PackageRoot::is_member)
+                    .map(|root| format!("{}/**/*.rs", root.path().display()))
+                    .map(|glob_pattern| lsp_types::FileSystemWatcher { glob_pattern, kind: None })
+                    .collect(),
+            };
+            let registration = lsp_types::Registration {
+                id: "file-watcher".to_string(),
+                method: "workspace/didChangeWatchedFiles".to_string(),
+                register_options: Some(serde_json::to_value(registration_options).unwrap()),
+            };
+            let params = lsp_types::RegistrationParams { registrations: vec![registration] };
+            let request = self.req_queue.outgoing.register(
+                lsp_types::request::RegisterCapability::METHOD.to_string(),
+                params,
+                |_, _| (),
+            );
+            self.send(request.into());
+        }
+
+        let mut change = AnalysisChange::new();
+
+        let project_folders = ProjectFolders::new(&workspaces);
+
+        self.proc_macro_client = match &self.config.proc_macro_srv {
+            None => ProcMacroClient::dummy(),
+            Some((path, args)) => match ProcMacroClient::extern_process(path.into(), args) {
+                Ok(it) => it,
+                Err(err) => {
+                    log::error!(
+                        "Failed to run ra_proc_macro_srv from path {}, error: {:?}",
+                        path.display(),
+                        err
+                    );
+                    ProcMacroClient::dummy()
+                }
+            },
+        };
+        let watch = match self.config.files.watcher {
+            FilesWatcher::Client => vec![],
+            FilesWatcher::Notify => project_folders.watch,
+        };
+        self.loader.handle.set_config(vfs::loader::Config { load: project_folders.load, watch });
+
+        // Create crate graph from all the workspaces
+        let crate_graph = {
+            let mut crate_graph = CrateGraph::default();
+            let vfs = &mut self.vfs.write().0;
+            let loader = &mut self.loader;
+            let mut load = |path: &AbsPath| {
+                let contents = loader.handle.load_sync(path);
+                let path = vfs::VfsPath::from(path.to_path_buf());
+                vfs.set_file_contents(path.clone(), contents);
+                vfs.file_id(&path)
+            };
+            for ws in workspaces.iter() {
+                crate_graph.extend(ws.to_crate_graph(
+                    self.config.cargo.target.as_deref(),
+                    &self.proc_macro_client,
+                    &mut load,
+                ));
+            }
+
+            crate_graph
+        };
+        change.set_crate_graph(crate_graph);
+
+        self.source_root_config = project_folders.source_root_config;
+        self.workspaces = Arc::new(workspaces);
+
+        self.analysis_host.apply_change(change);
+        self.process_changes();
+        self.reload_flycheck();
+    }
+
+    fn reload_flycheck(&mut self) {
+        let config = match self.config.flycheck.clone() {
+            Some(it) => it,
+            None => {
+                self.flycheck = None;
+                return;
+            }
+        };
+
+        // 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 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
+            }
+        })
+    }
+}
+
+#[derive(Default)]
+pub(crate) struct ProjectFolders {
+    pub(crate) load: Vec<vfs::loader::Entry>,
+    pub(crate) watch: Vec<usize>,
+    pub(crate) source_root_config: SourceRootConfig,
+}
+
+impl ProjectFolders {
+    pub(crate) fn new(workspaces: &[ProjectWorkspace]) -> ProjectFolders {
+        let mut res = ProjectFolders::default();
+        let mut fsc = FileSetConfig::builder();
+        let mut local_filesets = vec![];
+
+        for root in workspaces.iter().flat_map(|it| it.to_roots()) {
+            let path = root.path().to_owned();
+
+            let mut file_set_roots: Vec<VfsPath> = vec![];
+
+            let entry = if root.is_member() {
+                vfs::loader::Entry::local_cargo_package(path.to_path_buf())
+            } else {
+                vfs::loader::Entry::cargo_package_dependency(path.to_path_buf())
+            };
+            res.load.push(entry);
+            if root.is_member() {
+                res.watch.push(res.load.len() - 1);
+            }
+
+            if let Some(out_dir) = root.out_dir() {
+                let out_dir = out_dir.to_path_buf();
+                res.load.push(vfs::loader::Entry::rs_files_recursively(out_dir.clone()));
+                if root.is_member() {
+                    res.watch.push(res.load.len() - 1);
+                }
+                file_set_roots.push(out_dir.into());
+            }
+            file_set_roots.push(path.to_path_buf().into());
+
+            if root.is_member() {
+                local_filesets.push(fsc.len());
+            }
+            fsc.add_file_set(file_set_roots)
+        }
+
+        let fsc = fsc.build();
+        res.source_root_config = SourceRootConfig { fsc, local_filesets };
+
+        res
+    }
+}
+
+#[derive(Default, Debug)]
+pub(crate) struct SourceRootConfig {
+    pub(crate) fsc: FileSetConfig,
+    pub(crate) local_filesets: Vec<usize>,
+}
+
+impl SourceRootConfig {
+    pub(crate) fn partition(&self, vfs: &vfs::Vfs) -> Vec<SourceRoot> {
+        self.fsc
+            .partition(vfs)
+            .into_iter()
+            .enumerate()
+            .map(|(idx, file_set)| {
+                let is_local = self.local_filesets.contains(&idx);
+                if is_local {
+                    SourceRoot::new_local(file_set)
+                } else {
+                    SourceRoot::new_library(file_set)
+                }
+            })
+            .collect()
+    }
+}