3 files changed, 20 insertions, 7 deletions

diff --git a/crates/ra_analysis/src/db.rs b/crates/ra_analysis/src/db.rs
index d621b3b22..09d74b9e7 100644
--- a/crates/ra_analysis/src/db.rs
+++ b/crates/ra_analysis/src/db.rs
@@ -10,7 +10,8 @@ use rustc_hash::FxHashSet;
 use salsa;
 
 use crate::{
-    Cancelable,
+    db,
+    Cancelable, Canceled,
     module_map::{ModuleDescriptorQuery, ModuleTreeQuery, ModulesDatabase},
     symbol_index::SymbolIndex,
     FileId, FileResolverImp,
@@ -33,6 +34,14 @@ impl salsa::Database for RootDatabase {
     }
 }
 
+pub(crate) fn check_canceled(db: &impl salsa::Database) -> Cancelable<()> {
+    if db.salsa_runtime().is_current_revision_canceled() {
+        Err(Canceled)
+    } else {
+        Ok(())
+    }
+}
+
 impl salsa::ParallelDatabase for RootDatabase {
     fn fork(&self) -> Self {
         RootDatabase {
@@ -115,6 +124,7 @@ fn file_lines(db: &impl SyntaxDatabase, file_id: FileId) -> Arc<LineIndex> {
     Arc::new(LineIndex::new(&*text))
 }
 fn file_symbols(db: &impl SyntaxDatabase, file_id: FileId) -> Cancelable<Arc<SymbolIndex>> {
+    db::check_canceled(db)?;
     let syntax = db.file_syntax(file_id);
     Ok(Arc::new(SymbolIndex::for_file(file_id, syntax)))
 }
diff --git a/crates/ra_analysis/src/lib.rs b/crates/ra_analysis/src/lib.rs
index 189dbd9c2..03708d450 100644
--- a/crates/ra_analysis/src/lib.rs
+++ b/crates/ra_analysis/src/lib.rs
@@ -38,17 +38,17 @@ pub use ra_editor::{
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct Cancel;
+pub struct Canceled;
 
-pub type Cancelable<T> = Result<T, Cancel>;
+pub type Cancelable<T> = Result<T, Canceled>;
 
-impl std::fmt::Display for Cancel {
+impl std::fmt::Display for Canceled {
     fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         fmt.write_str("Canceled")
     }
 }
 
-impl std::error::Error for Cancel {
+impl std::error::Error for Canceled {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/crates/ra_analysis/src/module_map.rs b/crates/ra_analysis/src/module_map.rs
index 0c413becd..3c800265a 100644
--- a/crates/ra_analysis/src/module_map.rs
+++ b/crates/ra_analysis/src/module_map.rs
@@ -1,12 +1,13 @@
+use std::sync::Arc;
+
 use crate::{
+    db,
     Cancelable,
     db::SyntaxDatabase,
     descriptors::{ModuleDescriptor, ModuleTreeDescriptor},
     FileId,
 };
 
-use std::sync::Arc;
-
 salsa::query_group! {
     pub(crate) trait ModulesDatabase: SyntaxDatabase {
         fn module_tree() -> Cancelable<Arc<ModuleTreeDescriptor>> {
@@ -19,11 +20,13 @@ salsa::query_group! {
 }
 
 fn module_descriptor(db: &impl ModulesDatabase, file_id: FileId) -> Cancelable<Arc<ModuleDescriptor>> {
+    db::check_canceled(db)?;
     let file = db.file_syntax(file_id);
     Ok(Arc::new(ModuleDescriptor::new(file.ast())))
 }
 
 fn module_tree(db: &impl ModulesDatabase) -> Cancelable<Arc<ModuleTreeDescriptor>> {
+    db::check_canceled(db)?;
     let file_set = db.file_set();
     let mut files = Vec::new();
     for &file_id in file_set.files.iter() {