4 files changed, 58 insertions, 9 deletions

diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 8879a9161..3818160b7 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -44,6 +44,9 @@ config_data! {
         /// Show function name and docs in parameter hints.
         callInfo_full: bool = "true",
 
+        /// Use semantic tokens for strings. Disable to support injected grammars
+        semanticStringTokens: bool = "true",
+
         /// Automatically refresh project info via `cargo metadata` on
         /// `Cargo.toml` changes.
         cargo_autoreload: bool           = "true",
@@ -381,6 +384,9 @@ impl Config {
     pub fn line_folding_only(&self) -> bool {
         try_or!(self.caps.text_document.as_ref()?.folding_range.as_ref()?.line_folding_only?, false)
     }
+    pub fn semantic_strings(&self) -> bool {
+        self.data.semanticStringTokens
+    }
     pub fn hierarchical_symbols(&self) -> bool {
         try_or!(
             self.caps
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index f6e40f872..85dd73fca 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -1376,7 +1376,8 @@ pub(crate) fn handle_semantic_tokens_full(
     let line_index = snap.file_line_index(file_id)?;
 
     let highlights = snap.analysis.highlight(file_id)?;
-    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
+    let semantic_strings = snap.config.semantic_strings();
+    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights, semantic_strings);
 
     // Unconditionally cache the tokens
     snap.semantic_tokens_cache.lock().insert(params.text_document.uri, semantic_tokens.clone());
@@ -1395,8 +1396,8 @@ pub(crate) fn handle_semantic_tokens_full_delta(
     let line_index = snap.file_line_index(file_id)?;
 
     let highlights = snap.analysis.highlight(file_id)?;
-
-    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
+    let semantic_strings = snap.config.semantic_strings();
+    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights, semantic_strings);
 
     let mut cache = snap.semantic_tokens_cache.lock();
     let cached_tokens = cache.entry(params.text_document.uri).or_default();
@@ -1425,7 +1426,8 @@ pub(crate) fn handle_semantic_tokens_range(
     let line_index = snap.file_line_index(frange.file_id)?;
 
     let highlights = snap.analysis.highlight_range(frange)?;
-    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights);
+    let semantic_strings = snap.config.semantic_strings();
+    let semantic_tokens = to_proto::semantic_tokens(&text, &line_index, highlights, semantic_strings);
     Ok(Some(semantic_tokens.into()))
 }
 
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index ecf6fd12f..01ffe8db1 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -381,6 +381,7 @@ pub(crate) fn semantic_tokens(
     text: &str,
     line_index: &LineIndex,
     highlights: Vec<HlRange>,
+    include_strings: bool
 ) -> lsp_types::SemanticTokens {
     let id = TOKEN_RESULT_COUNTER.fetch_add(1, Ordering::SeqCst).to_string();
     let mut builder = semantic_tokens::SemanticTokensBuilder::new(id);
@@ -389,8 +390,11 @@ pub(crate) fn semantic_tokens(
         if highlight_range.highlight.is_empty() {
             continue;
         }
-        let (type_, mods) = semantic_token_type_and_modifiers(highlight_range.highlight);
-        let token_index = semantic_tokens::type_index(type_);
+        let (typ, mods) = semantic_token_type_and_modifiers(highlight_range.highlight);
+        if !include_strings && typ == lsp_types::SemanticTokenType::STRING {
+            continue;
+        }
+        let token_index = semantic_tokens::type_index(typ);
         let modifier_bitset = mods.0;
 
         for mut text_range in line_index.index.lines(highlight_range.range) {
diff --git a/crates/rust-analyzer/tests/rust-analyzer/main.rs b/crates/rust-analyzer/tests/rust-analyzer/main.rs
index 9e89209ea..62f34b643 100644
--- a/crates/rust-analyzer/tests/rust-analyzer/main.rs
+++ b/crates/rust-analyzer/tests/rust-analyzer/main.rs
@@ -18,15 +18,16 @@ use lsp_types::{
     notification::DidOpenTextDocument,
     request::{
         CodeActionRequest, Completion, Formatting, GotoTypeDefinition, HoverRequest,
-        WillRenameFiles,
+        SemanticTokensRangeRequest, WillRenameFiles
     },
     CodeActionContext, CodeActionParams, CompletionParams, DidOpenTextDocumentParams,
     DocumentFormattingParams, FileRename, FormattingOptions, GotoDefinitionParams, HoverParams,
-    PartialResultParams, Position, Range, RenameFilesParams, TextDocumentItem,
+    PartialResultParams, Position, Range, RenameFilesParams, SemanticTokensRangeParams, TextDocumentItem,
     TextDocumentPositionParams, WorkDoneProgressParams,
+    SemanticTokens
 };
 use rust_analyzer::lsp_ext::{OnEnter, Runnables, RunnablesParams};
-use serde_json::json;
+use serde_json::{from_value, json};
 use test_utils::skip_slow_tests;
 
 use crate::{
@@ -38,6 +39,42 @@ const PROFILE: &str = "";
 // const PROFILE: &'static str = "*@3>100";
 
 #[test]
+fn can_disable_semantic_strings() {
+    if skip_slow_tests() {
+        return;
+    }
+
+    [true, false].iter().for_each(|semantic_strings| {
+        let server = Project::with_fixture(
+            r#"
+//- /Cargo.toml
+[package]
+name = "foo"
+version = "0.0.0"
+
+//- /src/lib.rs
+const foo: &'static str = "hi";
+"#,
+        )
+        .with_config(serde_json::json!({
+            "semanticStringTokens": semantic_strings 
+        }))
+        .server().wait_until_workspace_is_loaded();
+
+        let res = server.send_request::<SemanticTokensRangeRequest>(SemanticTokensRangeParams {
+            text_document: server.doc_id("src/lib.rs"),
+            partial_result_params: PartialResultParams::default(),
+            work_done_progress_params: WorkDoneProgressParams::default(),
+            range: Range::new(Position::new(0, 26), Position::new(0, 30)),
+        });
+
+        let tok_res: SemanticTokens = from_value(res).expect("invalid server response");
+        assert!(tok_res.data.len() == *semantic_strings as usize);
+    });
+}
+
+
+#[test]
 fn completes_items_from_standard_library() {
     if skip_slow_tests() {
         return;