lsp: Watch paths outside of worktrees at language servers request (#17499)

Another stab at https://github.com/zed-industries/zed/pull/17173, this
time fixing the segfault found in
https://github.com/zed-industries/zed/pull/17206

Release Notes:

- Improved language server reliability in multi-worktree projects and
monorepo. We now notify the language server more reliably about which
files have changed.

crates/assistant/src/prompts.rs

@@ -123,7 +123,7 @@ impl PromptBuilder {
                         if params.fs.is_dir(parent_dir).await {
                             let (mut changes, _watcher) = params.fs.watch(parent_dir, Duration::from_secs(1)).await;
                             while let Some(changed_paths) = changes.next().await {
-                                if changed_paths.iter().any(|p| p == &templates_dir) {
+                                if changed_paths.iter().any(|p| &p.path == &templates_dir) {
                                     let mut log_message = format!("Prompt template overrides directory detected at {}", templates_dir.display());
                                     if let Ok(target) = params.fs.read_link(&templates_dir).await {
                                         log_message.push_str(" -> ");
@@ -162,18 +162,18 @@ impl PromptBuilder {
                     let mut combined_changes = futures::stream::select(changes, parent_changes);
 
                     while let Some(changed_paths) = combined_changes.next().await {
-                        if changed_paths.iter().any(|p| p == &templates_dir) {
+                        if changed_paths.iter().any(|p| &p.path == &templates_dir) {
                             if !params.fs.is_dir(&templates_dir).await {
                                 log::info!("Prompt template overrides directory removed. Restoring built-in prompt templates.");
                                 Self::register_built_in_templates(&mut handlebars.lock()).log_err();
                                 break;
                             }
                         }
-                        for changed_path in changed_paths {
+                        for event in changed_paths {
-                            if changed_path.starts_with(&templates_dir) && changed_path.extension().map_or(false, |ext| ext == "hbs") {
+                            if event.path.starts_with(&templates_dir) && event.path.extension().map_or(false, |ext| ext == "hbs") {
-                                log::info!("Reloading prompt template override: {}", changed_path.display());
+                                log::info!("Reloading prompt template override: {}", event.path.display());
-                                if let Some(content) = params.fs.load(&changed_path).await.log_err() {
+                                if let Some(content) = params.fs.load(&event.path).await.log_err() {
-                                    let file_name = changed_path.file_stem().unwrap().to_string_lossy();
+                                    let file_name = event.path.file_stem().unwrap().to_string_lossy();
                                     handlebars.lock().register_template_string(&file_name, content).log_err();
                                 }
                             }

crates/extension/src/extension_store.rs

@@ -369,9 +369,9 @@ impl ExtensionStore {
             let installed_dir = this.installed_dir.clone();
             async move {
                 let (mut paths, _) = fs.watch(&installed_dir, FS_WATCH_LATENCY).await;
-                while let Some(paths) = paths.next().await {
+                while let Some(events) = paths.next().await {
-                    for path in paths {
+                    for event in events {
-                        let Ok(event_path) = path.strip_prefix(&installed_dir) else {
+                        let Ok(event_path) = event.path.strip_prefix(&installed_dir) else {
                             continue;
                         };
 

crates/fs/src/fs.rs

@@ -45,6 +45,25 @@ pub trait Watcher: Send + Sync {
     fn remove(&self, path: &Path) -> Result<()>;
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub enum PathEventKind {
+    Removed,
+    Created,
+    Changed,
+}
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
+pub struct PathEvent {
+    pub path: PathBuf,
+    pub kind: Option<PathEventKind>,
+}
+
+impl From<PathEvent> for PathBuf {
+    fn from(event: PathEvent) -> Self {
+        event.path
+    }
+}
+
 #[async_trait::async_trait]
 pub trait Fs: Send + Sync {
     async fn create_dir(&self, path: &Path) -> Result<()>;
@@ -92,7 +111,7 @@ pub trait Fs: Send + Sync {
         path: &Path,
         latency: Duration,
     ) -> (
-        Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>,
+        Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>,
         Arc<dyn Watcher>,
     );
 
@@ -469,17 +488,38 @@ impl Fs for RealFs {
         path: &Path,
         latency: Duration,
     ) -> (
-        Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>,
+        Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>,
         Arc<dyn Watcher>,
     ) {
-        use fsevent::EventStream;
+        use fsevent::{EventStream, StreamFlags};
 
         let (tx, rx) = smol::channel::unbounded();
         let (stream, handle) = EventStream::new(&[path], latency);
         std::thread::spawn(move || {
             stream.run(move |events| {
-                smol::block_on(tx.send(events.into_iter().map(|event| event.path).collect()))
+                smol::block_on(
-                    .is_ok()
+                    tx.send(
+                        events
+                            .into_iter()
+                            .map(|event| {
+                                let kind = if event.flags.contains(StreamFlags::ITEM_REMOVED) {
+                                    Some(PathEventKind::Removed)
+                                } else if event.flags.contains(StreamFlags::ITEM_CREATED) {
+                                    Some(PathEventKind::Created)
+                                } else if event.flags.contains(StreamFlags::ITEM_MODIFIED) {
+                                    Some(PathEventKind::Changed)
+                                } else {
+                                    None
+                                };
+                                PathEvent {
+                                    path: event.path,
+                                    kind,
+                                }
+                            })
+                            .collect(),
+                    ),
+                )
+                .is_ok()
             });
         });
 
@@ -498,32 +538,46 @@ impl Fs for RealFs {
         path: &Path,
         latency: Duration,
     ) -> (
-        Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>,
+        Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>,
         Arc<dyn Watcher>,
     ) {
+        use notify::EventKind;
         use parking_lot::Mutex;
 
         let (tx, rx) = smol::channel::unbounded();
-        let pending_paths: Arc<Mutex<Vec<PathBuf>>> = Default::default();
+        let pending_paths: Arc<Mutex<Vec<PathEvent>>> = Default::default();
         let root_path = path.to_path_buf();
 
         watcher::global(|g| {
             let tx = tx.clone();
             let pending_paths = pending_paths.clone();
             g.add(move |event: &notify::Event| {
+                let kind = match event.kind {
+                    EventKind::Create(_) => Some(PathEventKind::Created),
+                    EventKind::Modify(_) => Some(PathEventKind::Changed),
+                    EventKind::Remove(_) => Some(PathEventKind::Removed),
+                    _ => None,
+                };
                 let mut paths = event
                     .paths
                     .iter()
-                    .filter(|path| path.starts_with(&root_path))
+                    .filter_map(|path| {
-                    .cloned()
+                        path.starts_with(&root_path).then(|| PathEvent {
+                            path: path.clone(),
+                            kind,
+                        })
+                    })
                     .collect::<Vec<_>>();
+
                 if !paths.is_empty() {
                     paths.sort();
                     let mut pending_paths = pending_paths.lock();
                     if pending_paths.is_empty() {
                         tx.try_send(()).ok();
                     }
-                    util::extend_sorted(&mut *pending_paths, paths, usize::MAX, PathBuf::cmp);
+                    util::extend_sorted(&mut *pending_paths, paths, usize::MAX, |a, b| {
+                        a.path.cmp(&b.path)
+                    });
                 }
             })
         })
@@ -561,10 +615,10 @@ impl Fs for RealFs {
         path: &Path,
         _latency: Duration,
     ) -> (
-        Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>,
+        Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>,
         Arc<dyn Watcher>,
     ) {
-        use notify::Watcher;
+        use notify::{EventKind, Watcher};
 
         let (tx, rx) = smol::channel::unbounded();
 
@@ -572,7 +626,21 @@ impl Fs for RealFs {
             let tx = tx.clone();
             move |event: Result<notify::Event, _>| {
                 if let Some(event) = event.log_err() {
-                    tx.try_send(event.paths).ok();
+                    let kind = match event.kind {
+                        EventKind::Create(_) => Some(PathEventKind::Created),
+                        EventKind::Modify(_) => Some(PathEventKind::Changed),
+                        EventKind::Remove(_) => Some(PathEventKind::Removed),
+                        _ => None,
+                    };
+
+                    tx.try_send(
+                        event
+                            .paths
+                            .into_iter()
+                            .map(|path| PathEvent { path, kind })
+                            .collect::<Vec<_>>(),
+                    )
+                    .ok();
                 }
             }
         })
@@ -682,9 +750,9 @@ struct FakeFsState {
     root: Arc<Mutex<FakeFsEntry>>,
     next_inode: u64,
     next_mtime: SystemTime,
-    event_txs: Vec<smol::channel::Sender<Vec<PathBuf>>>,
+    event_txs: Vec<smol::channel::Sender<Vec<PathEvent>>>,
     events_paused: bool,
-    buffered_events: Vec<PathBuf>,
+    buffered_events: Vec<PathEvent>,
     metadata_call_count: usize,
     read_dir_call_count: usize,
 }
@@ -793,11 +861,14 @@ impl FakeFsState {
 
     fn emit_event<I, T>(&mut self, paths: I)
     where
-        I: IntoIterator<Item = T>,
+        I: IntoIterator<Item = (T, Option<PathEventKind>)>,
         T: Into<PathBuf>,
     {
         self.buffered_events
-            .extend(paths.into_iter().map(Into::into));
+            .extend(paths.into_iter().map(|(path, kind)| PathEvent {
+                path: path.into(),
+                kind,
+            }));
 
         if !self.events_paused {
             self.flush_events(self.buffered_events.len());
@@ -872,7 +943,7 @@ impl FakeFs {
                 Ok(())
             })
             .unwrap();
-        state.emit_event([path.to_path_buf()]);
+        state.emit_event([(path.to_path_buf(), None)]);
     }
 
     pub async fn insert_file(&self, path: impl AsRef<Path>, content: Vec<u8>) {
@@ -895,7 +966,7 @@ impl FakeFs {
                 }
             })
             .unwrap();
-        state.emit_event([path]);
+        state.emit_event([(path, None)]);
     }
 
     fn write_file_internal(&self, path: impl AsRef<Path>, content: Vec<u8>) -> Result<()> {
@@ -910,18 +981,24 @@ impl FakeFs {
             mtime,
             content,
         }));
-        state.write_path(path, move |entry| {
+        let mut kind = None;
-            match entry {
+        state.write_path(path, {
-                btree_map::Entry::Vacant(e) => {
+            let kind = &mut kind;
-                    e.insert(file);
+            move |entry| {
-                }
+                match entry {
-                btree_map::Entry::Occupied(mut e) => {
+                    btree_map::Entry::Vacant(e) => {
-                    *e.get_mut() = file;
+                        *kind = Some(PathEventKind::Created);
+                        e.insert(file);
+                    }
+                    btree_map::Entry::Occupied(mut e) => {
+                        *kind = Some(PathEventKind::Changed);
+                        *e.get_mut() = file;
+                    }
                 }
+                Ok(())
             }
-            Ok(())
         })?;
-        state.emit_event([path]);
+        state.emit_event([(path, kind)]);
         Ok(())
     }
 
@@ -1030,7 +1107,7 @@ impl FakeFs {
             f(&mut repo_state);
 
             if emit_git_event {
-                state.emit_event([dot_git]);
+                state.emit_event([(dot_git, None)]);
             }
         } else {
             panic!("not a directory");
@@ -1081,7 +1158,7 @@ impl FakeFs {
         self.state.lock().emit_event(
             statuses
                 .iter()
-                .map(|(path, _)| dot_git.parent().unwrap().join(path)),
+                .map(|(path, _)| (dot_git.parent().unwrap().join(path), None)),
         );
     }
 
@@ -1251,7 +1328,7 @@ impl Fs for FakeFs {
             state.next_inode += 1;
             state.write_path(&cur_path, |entry| {
                 entry.or_insert_with(|| {
-                    created_dirs.push(cur_path.clone());
+                    created_dirs.push((cur_path.clone(), Some(PathEventKind::Created)));
                     Arc::new(Mutex::new(FakeFsEntry::Dir {
                         inode,
                         mtime,
@@ -1263,7 +1340,7 @@ impl Fs for FakeFs {
             })?
         }
 
-        self.state.lock().emit_event(&created_dirs);
+        self.state.lock().emit_event(created_dirs);
         Ok(())
     }
 
@@ -1279,10 +1356,12 @@ impl Fs for FakeFs {
             mtime,
             content: Vec::new(),
         }));
+        let mut kind = Some(PathEventKind::Created);
         state.write_path(path, |entry| {
             match entry {
                 btree_map::Entry::Occupied(mut e) => {
                     if options.overwrite {
+                        kind = Some(PathEventKind::Changed);
                         *e.get_mut() = file;
                     } else if !options.ignore_if_exists {
                         return Err(anyhow!("path already exists: {}", path.display()));
@@ -1294,7 +1373,7 @@ impl Fs for FakeFs {
             }
             Ok(())
         })?;
-        state.emit_event([path]);
+        state.emit_event([(path, kind)]);
         Ok(())
     }
 
@@ -1313,7 +1392,8 @@ impl Fs for FakeFs {
                 }
             })
             .unwrap();
-        state.emit_event([path]);
+        state.emit_event([(path, None)]);
+
         Ok(())
     }
 
@@ -1388,7 +1468,10 @@ impl Fs for FakeFs {
             })
             .unwrap();
 
-        state.emit_event(&[old_path, new_path]);
+        state.emit_event([
+            (old_path, Some(PathEventKind::Removed)),
+            (new_path, Some(PathEventKind::Created)),
+        ]);
         Ok(())
     }
 
@@ -1403,9 +1486,11 @@ impl Fs for FakeFs {
         state.next_mtime += Duration::from_nanos(1);
         let source_entry = state.read_path(&source)?;
         let content = source_entry.lock().file_content(&source)?.clone();
+        let mut kind = Some(PathEventKind::Created);
         let entry = state.write_path(&target, |e| match e {
             btree_map::Entry::Occupied(e) => {
                 if options.overwrite {
+                    kind = Some(PathEventKind::Changed);
                     Ok(Some(e.get().clone()))
                 } else if !options.ignore_if_exists {
                     return Err(anyhow!("{target:?} already exists"));
@@ -1425,7 +1510,7 @@ impl Fs for FakeFs {
         if let Some(entry) = entry {
             entry.lock().set_file_content(&target, content)?;
         }
-        state.emit_event(&[target]);
+        state.emit_event([(target, kind)]);
         Ok(())
     }
 
@@ -1462,7 +1547,7 @@ impl Fs for FakeFs {
                 e.remove();
             }
         }
-        state.emit_event(&[path]);
+        state.emit_event([(path, Some(PathEventKind::Removed))]);
         Ok(())
     }
 
@@ -1491,7 +1576,7 @@ impl Fs for FakeFs {
                 e.remove();
             }
         }
-        state.emit_event(&[path]);
+        state.emit_event([(path, Some(PathEventKind::Removed))]);
         Ok(())
     }
 
@@ -1632,7 +1717,7 @@ impl Fs for FakeFs {
         path: &Path,
         _: Duration,
     ) -> (
-        Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>,
+        Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>,
         Arc<dyn Watcher>,
     ) {
         self.simulate_random_delay().await;
@@ -1642,7 +1727,9 @@ impl Fs for FakeFs {
         let executor = self.executor.clone();
         (
             Box::pin(futures::StreamExt::filter(rx, move |events| {
-                let result = events.iter().any(|evt_path| evt_path.starts_with(&path));
+                let result = events
+                    .iter()
+                    .any(|evt_path| evt_path.path.starts_with(&path));
                 let executor = executor.clone();
                 async move {
                     executor.simulate_random_delay().await;

crates/project/src/lsp_store.rs

@@ -22,8 +22,8 @@ use futures::{
 };
 use globset::{Glob, GlobSet, GlobSetBuilder};
 use gpui::{
-    AppContext, AsyncAppContext, Entity, EventEmitter, Model, ModelContext, PromptLevel, Task,
+    AppContext, AsyncAppContext, Context, Entity, EventEmitter, Model, ModelContext, PromptLevel,
-    WeakModel,
+    Task, WeakModel,
 };
 use http_client::HttpClient;
 use itertools::Itertools;
@@ -58,7 +58,7 @@ use std::{
     convert::TryInto,
     ffi::OsStr,
     iter, mem,
-    ops::Range,
+    ops::{ControlFlow, Range},
     path::{self, Path, PathBuf},
     process::Stdio,
     str,
@@ -103,7 +103,7 @@ pub struct LspStore {
     language_server_ids: HashMap<(WorktreeId, LanguageServerName), LanguageServerId>,
     language_server_statuses: BTreeMap<LanguageServerId, LanguageServerStatus>,
     last_workspace_edits_by_language_server: HashMap<LanguageServerId, ProjectTransaction>,
-    language_server_watched_paths: HashMap<LanguageServerId, HashMap<WorktreeId, GlobSet>>,
+    language_server_watched_paths: HashMap<LanguageServerId, Model<LanguageServerWatchedPaths>>,
     language_server_watcher_registrations:
         HashMap<LanguageServerId, HashMap<String, Vec<FileSystemWatcher>>>,
     active_entry: Option<ProjectEntryId>,
@@ -3227,6 +3227,38 @@ impl LspStore {
             .map(|(key, value)| (*key, value))
     }
 
+    fn lsp_notify_abs_paths_changed(
+        &mut self,
+        server_id: LanguageServerId,
+        changes: Vec<PathEvent>,
+    ) {
+        maybe!({
+            let server = self.language_server_for_id(server_id)?;
+            let changes = changes
+                .into_iter()
+                .filter_map(|event| {
+                    let typ = match event.kind? {
+                        PathEventKind::Created => lsp::FileChangeType::CREATED,
+                        PathEventKind::Removed => lsp::FileChangeType::DELETED,
+                        PathEventKind::Changed => lsp::FileChangeType::CHANGED,
+                    };
+                    Some(lsp::FileEvent {
+                        uri: lsp::Url::from_file_path(&event.path).ok()?,
+                        typ,
+                    })
+                })
+                .collect::<Vec<_>>();
+            if !changes.is_empty() {
+                server
+                    .notify::<lsp::notification::DidChangeWatchedFiles>(
+                        lsp::DidChangeWatchedFilesParams { changes },
+                    )
+                    .log_err();
+            }
+            Some(())
+        });
+    }
+
     fn rebuild_watched_paths(
         &mut self,
         language_server_id: LanguageServerId,
@@ -3239,62 +3271,176 @@ impl LspStore {
             return;
         };
 
-        let watched_paths = self
+        let mut worktree_globs = HashMap::default();
-            .language_server_watched_paths
+        let mut abs_globs = HashMap::default();
-            .entry(language_server_id)
+        log::trace!(
-            .or_default();
+            "Processing new watcher paths for language server with id {}",
+            language_server_id
+        );
 
-        let mut builders = HashMap::default();
+        let worktrees = self
+            .worktree_store
+            .read(cx)
+            .worktrees()
+            .filter_map(|worktree| {
+                self.language_servers_for_worktree(worktree.read(cx).id())
+                    .find(|(_, _, server)| server.server_id() == language_server_id)
+                    .map(|_| worktree)
+            })
+            .collect::<Vec<_>>();
+
+        enum PathToWatch {
+            Worktree {
+                literal_prefix: Arc<Path>,
+                pattern: String,
+            },
+            Absolute {
+                path: Arc<Path>,
+                pattern: String,
+            },
+        }
         for watcher in watchers.values().flatten() {
-            for worktree in self.worktree_store.read(cx).worktrees().collect::<Vec<_>>() {
+            let mut found_host = false;
+            for worktree in &worktrees {
                 let glob_is_inside_worktree = worktree.update(cx, |tree, _| {
-                    if let Some(abs_path) = tree.abs_path().to_str() {
+                    if let Some(worktree_root_path) = tree.abs_path().to_str() {
-                        let relative_glob_pattern = match &watcher.glob_pattern {
+                        let path_to_watch = match &watcher.glob_pattern {
-                            lsp::GlobPattern::String(s) => Some(
+                            lsp::GlobPattern::String(s) => {
-                                s.strip_prefix(abs_path)
+                                match s.strip_prefix(worktree_root_path) {
-                                    .unwrap_or(s)
+                                    Some(relative) => {
-                                    .strip_prefix(std::path::MAIN_SEPARATOR)
+                                        let pattern = relative
-                                    .unwrap_or(s),
+                                            .strip_prefix(std::path::MAIN_SEPARATOR)
-                            ),
+                                            .unwrap_or(relative)
+                                            .to_owned();
+                                        let literal_prefix = glob_literal_prefix(&pattern);
+
+                                        let literal_prefix = Arc::from(PathBuf::from(
+                                            literal_prefix
+                                                .strip_prefix(std::path::MAIN_SEPARATOR)
+                                                .unwrap_or(literal_prefix),
+                                        ));
+                                        PathToWatch::Worktree {
+                                            literal_prefix,
+                                            pattern,
+                                        }
+                                    }
+                                    None => {
+                                        let path = glob_literal_prefix(s);
+                                        let glob = &s[path.len()..];
+                                        let pattern = glob
+                                            .strip_prefix(std::path::MAIN_SEPARATOR)
+                                            .unwrap_or(glob)
+                                            .to_owned();
+                                        let path = if Path::new(path).components().next().is_none()
+                                        {
+                                            Arc::from(Path::new("/"))
+                                        } else {
+                                            PathBuf::from(path).into()
+                                        };
+
+                                        PathToWatch::Absolute { path, pattern }
+                                    }
+                                }
+                            }
                             lsp::GlobPattern::Relative(rp) => {
-                                let base_uri = match &rp.base_uri {
+                                let Ok(mut base_uri) = match &rp.base_uri {
                                     lsp::OneOf::Left(workspace_folder) => &workspace_folder.uri,
                                     lsp::OneOf::Right(base_uri) => base_uri,
+                                }
+                                .to_file_path() else {
+                                    return false;
                                 };
-                                base_uri.to_file_path().ok().and_then(|file_path| {
+
-                                    (file_path.to_str() == Some(abs_path))
+                                match base_uri.strip_prefix(worktree_root_path) {
-                                        .then_some(rp.pattern.as_str())
+                                    Ok(relative) => {
-                                })
+                                        let mut literal_prefix = relative.to_owned();
+                                        literal_prefix.push(glob_literal_prefix(&rp.pattern));
+
+                                        PathToWatch::Worktree {
+                                            literal_prefix: literal_prefix.into(),
+                                            pattern: rp.pattern.clone(),
+                                        }
+                                    }
+                                    Err(_) => {
+                                        let path = glob_literal_prefix(&rp.pattern);
+                                        let glob = &rp.pattern[path.len()..];
+                                        let pattern = glob
+                                            .strip_prefix(std::path::MAIN_SEPARATOR)
+                                            .unwrap_or(glob)
+                                            .to_owned();
+                                        base_uri.push(path);
+
+                                        let path = if base_uri.components().next().is_none() {
+                                            Arc::from(Path::new("/"))
+                                        } else {
+                                            base_uri.into()
+                                        };
+                                        PathToWatch::Absolute { path, pattern }
+                                    }
+                                }
                             }
                         };
-                        if let Some(relative_glob_pattern) = relative_glob_pattern {
+                        match path_to_watch {
-                            let literal_prefix = glob_literal_prefix(relative_glob_pattern);
+                            PathToWatch::Worktree {
-                            tree.as_local_mut()
+                                literal_prefix,
-                                .unwrap()
+                                pattern,
-                                .add_path_prefix_to_scan(Path::new(literal_prefix).into());
+                            } => {
-                            if let Some(glob) = Glob::new(relative_glob_pattern).log_err() {
+                                if let Some((tree, glob)) =
-                                builders
+                                    tree.as_local_mut().zip(Glob::new(&pattern).log_err())
-                                    .entry(tree.id())
+                                {
-                                    .or_insert_with(GlobSetBuilder::new)
+                                    tree.add_path_prefix_to_scan(literal_prefix);
-                                    .add(glob);
+                                    worktree_globs
+                                        .entry(tree.id())
+                                        .or_insert_with(GlobSetBuilder::new)
+                                        .add(glob);
+                                } else {
+                                    return false;
+                                }
+                            }
+                            PathToWatch::Absolute { path, pattern } => {
+                                if let Some(glob) = Glob::new(&pattern).log_err() {
+                                    abs_globs
+                                        .entry(path)
+                                        .or_insert_with(GlobSetBuilder::new)
+                                        .add(glob);
+                                }
                             }
-                            return true;
                         }
+                        return true;
                     }
                     false
                 });
                 if glob_is_inside_worktree {
-                    break;
+                    log::trace!(
+                        "Watcher pattern `{}` has been attached to the worktree at `{}`",
+                        serde_json::to_string(&watcher.glob_pattern).unwrap(),
+                        worktree.read(cx).abs_path().display()
+                    );
+                    found_host = true;
                 }
             }
+            if !found_host {
+                log::error!(
+                    "Watcher pattern `{}` has not been attached to any worktree or absolute path",
+                    serde_json::to_string(&watcher.glob_pattern).unwrap()
+                )
+            }
         }
 
-        watched_paths.clear();
+        let mut watch_builder = LanguageServerWatchedPathsBuilder::default();
-        for (worktree_id, builder) in builders {
+        for (worktree_id, builder) in worktree_globs {
             if let Ok(globset) = builder.build() {
-                watched_paths.insert(worktree_id, globset);
+                watch_builder.watch_worktree(worktree_id, globset);
             }
         }
+        for (abs_path, builder) in abs_globs {
+            if let Ok(globset) = builder.build() {
+                watch_builder.watch_abs_path(abs_path, globset);
+            }
+        }
+        let watcher = watch_builder.build(self.fs.clone(), language_server_id, cx);
+        self.language_server_watched_paths
+            .insert(language_server_id, watcher);
 
         cx.notify();
     }
@@ -5427,7 +5573,7 @@ impl LspStore {
         }
     }
 
-    pub fn update_local_worktree_language_servers(
+    pub(super) fn update_local_worktree_language_servers(
         &mut self,
         worktree_handle: &Model<Worktree>,
         changes: &[(Arc<Path>, ProjectEntryId, PathChange)],
@@ -5456,7 +5602,7 @@ impl LspStore {
                 if let Some(watched_paths) = self
                     .language_server_watched_paths
                     .get(&server_id)
-                    .and_then(|paths| paths.get(&worktree_id))
+                    .and_then(|paths| paths.read(cx).worktree_paths.get(&worktree_id))
                 {
                     let params = lsp::DidChangeWatchedFilesParams {
                         changes: changes
@@ -5991,6 +6137,102 @@ pub enum LanguageServerToQuery {
     Other(LanguageServerId),
 }
 
+#[derive(Default)]
+struct LanguageServerWatchedPaths {
+    worktree_paths: HashMap<WorktreeId, GlobSet>,
+    abs_paths: HashMap<Arc<Path>, (GlobSet, Task<()>)>,
+}
+
+#[derive(Default)]
+struct LanguageServerWatchedPathsBuilder {
+    worktree_paths: HashMap<WorktreeId, GlobSet>,
+    abs_paths: HashMap<Arc<Path>, GlobSet>,
+}
+
+impl LanguageServerWatchedPathsBuilder {
+    fn watch_worktree(&mut self, worktree_id: WorktreeId, glob_set: GlobSet) {
+        self.worktree_paths.insert(worktree_id, glob_set);
+    }
+    fn watch_abs_path(&mut self, path: Arc<Path>, glob_set: GlobSet) {
+        self.abs_paths.insert(path, glob_set);
+    }
+    fn build(
+        self,
+        fs: Arc<dyn Fs>,
+        language_server_id: LanguageServerId,
+        cx: &mut ModelContext<LspStore>,
+    ) -> Model<LanguageServerWatchedPaths> {
+        let project = cx.weak_model();
+
+        cx.new_model(|cx| {
+            let this_id = cx.entity_id();
+            const LSP_ABS_PATH_OBSERVE: Duration = Duration::from_millis(100);
+            let abs_paths = self
+                .abs_paths
+                .into_iter()
+                .map(|(abs_path, globset)| {
+                    let task = cx.spawn({
+                        let abs_path = abs_path.clone();
+                        let fs = fs.clone();
+
+                        let lsp_store = project.clone();
+                        |_, mut cx| async move {
+                            maybe!(async move {
+                                let mut push_updates =
+                                    fs.watch(&abs_path, LSP_ABS_PATH_OBSERVE).await;
+                                while let Some(update) = push_updates.0.next().await {
+                                    let action = lsp_store
+                                        .update(&mut cx, |this, cx| {
+                                            let Some(watcher) = this
+                                                .language_server_watched_paths
+                                                .get(&language_server_id)
+                                            else {
+                                                return ControlFlow::Break(());
+                                            };
+                                            if watcher.entity_id() != this_id {
+                                                // This watcher is no longer registered on the project, which means that we should
+                                                // cease operations.
+                                                return ControlFlow::Break(());
+                                            }
+                                            let (globs, _) = watcher
+                                                .read(cx)
+                                                .abs_paths
+                                                .get(&abs_path)
+                                                .expect(
+                                                "Watched abs path is not registered with a watcher",
+                                            );
+                                            let matching_entries = update
+                                                .into_iter()
+                                                .filter(|event| globs.is_match(&event.path))
+                                                .collect::<Vec<_>>();
+                                            this.lsp_notify_abs_paths_changed(
+                                                language_server_id,
+                                                matching_entries,
+                                            );
+                                            ControlFlow::Continue(())
+                                        })
+                                        .ok()?;
+
+                                    if action.is_break() {
+                                        break;
+                                    }
+                                }
+                                Some(())
+                            })
+                            .await;
+                        }
+                    });
+                    (abs_path, (globset, task))
+                })
+                .collect();
+            LanguageServerWatchedPaths {
+                worktree_paths: self.worktree_paths,
+                abs_paths,
+            }
+        })
+    }
+}
+
 struct LspBufferSnapshot {
     version: i32,
     snapshot: TextBufferSnapshot,
@@ -6094,7 +6336,9 @@ impl DiagnosticSummary {
 }
 
 fn glob_literal_prefix(glob: &str) -> &str {
-    let mut literal_end = 0;
+    let is_absolute = glob.starts_with(path::MAIN_SEPARATOR);
+
+    let mut literal_end = is_absolute as usize;
     for (i, part) in glob.split(path::MAIN_SEPARATOR).enumerate() {
         if part.contains(['*', '?', '{', '}']) {
             break;
@@ -6106,6 +6350,7 @@ fn glob_literal_prefix(glob: &str) -> &str {
             literal_end += part.len();
         }
     }
+    let literal_end = literal_end.min(glob.len());
     &glob[..literal_end]
 }
 

crates/snippet_provider/src/lib.rs

@@ -169,7 +169,12 @@ impl SnippetProvider {
 
             let (mut entries, _) = watcher.await;
             while let Some(entries) = entries.next().await {
-                process_updates(this.clone(), entries, cx.clone()).await?;
+                process_updates(
+                    this.clone(),
+                    entries.into_iter().map(|event| event.path).collect(),
+                    cx.clone(),
+                )
+                .await?;
             }
             Ok(())
         })

crates/worktree/src/worktree.rs

@@ -7,7 +7,7 @@ use ::ignore::gitignore::{Gitignore, GitignoreBuilder};
 use anyhow::{anyhow, Context as _, Result};
 use clock::ReplicaId;
 use collections::{HashMap, HashSet, VecDeque};
-use fs::{copy_recursive, Fs, RemoveOptions, Watcher};
+use fs::{copy_recursive, Fs, PathEvent, RemoveOptions, Watcher};
 use futures::{
     channel::{
         mpsc::{self, UnboundedSender},
@@ -1048,7 +1048,11 @@ impl LocalWorktree {
                     watcher,
                 };
 
-                scanner.run(events).await;
+                scanner
+                    .run(Box::pin(
+                        events.map(|events| events.into_iter().map(Into::into).collect()),
+                    ))
+                    .await;
             }
         });
         let scan_state_updater = cx.spawn(|this, mut cx| async move {
@@ -3512,7 +3516,7 @@ enum BackgroundScannerPhase {
 }
 
 impl BackgroundScanner {
-    async fn run(&mut self, mut fs_events_rx: Pin<Box<dyn Send + Stream<Item = Vec<PathBuf>>>>) {
+    async fn run(&mut self, mut fs_events_rx: Pin<Box<dyn Send + Stream<Item = Vec<PathEvent>>>>) {
         use futures::FutureExt as _;
 
         // If the worktree root does not contain a git repository, then find
@@ -3593,7 +3597,8 @@ impl BackgroundScanner {
             while let Poll::Ready(Some(more_paths)) = futures::poll!(fs_events_rx.next()) {
                 paths.extend(more_paths);
             }
-            self.process_events(paths).await;
+            self.process_events(paths.into_iter().map(Into::into).collect())
+                .await;
         }
 
         // Continue processing events until the worktree is dropped.
@@ -3634,7 +3639,7 @@ impl BackgroundScanner {
                     while let Poll::Ready(Some(more_paths)) = futures::poll!(fs_events_rx.next()) {
                         paths.extend(more_paths);
                     }
-                    self.process_events(paths.clone()).await;
+                    self.process_events(paths.into_iter().map(Into::into).collect()).await;
                 }
             }
         }

crates/zed/src/main.rs

@@ -1153,13 +1153,13 @@ fn watch_themes(fs: Arc<dyn fs::Fs>, cx: &mut AppContext) {
             .await;
 
         while let Some(paths) = events.next().await {
-            for path in paths {
+            for event in paths {
-                if fs.metadata(&path).await.ok().flatten().is_some() {
+                if fs.metadata(&event.path).await.ok().flatten().is_some() {
                     if let Some(theme_registry) =
                         cx.update(|cx| ThemeRegistry::global(cx).clone()).log_err()
                     {
                         if let Some(()) = theme_registry
-                            .load_user_theme(&path, fs.clone())
+                            .load_user_theme(&event.path, fs.clone())
                             .await
                             .log_err()
                         {
@@ -1188,8 +1188,10 @@ fn watch_languages(fs: Arc<dyn fs::Fs>, languages: Arc<LanguageRegistry>, cx: &m
     cx.spawn(|_| async move {
         let (mut events, _) = fs.watch(path.as_path(), Duration::from_millis(100)).await;
         while let Some(event) = events.next().await {
-            let has_language_file = event.iter().any(|path| {
+            let has_language_file = event.iter().any(|event| {
-                path.extension()
+                event
+                    .path
+                    .extension()
                     .map(|ext| ext.to_string_lossy().as_ref() == "scm")
                     .unwrap_or(false)
             });