Add support for textDocument/documentHighlight request (#308)

* Add support for textDocument/documentHighlight request

* Search for references only in the current file

vhdl_lang/src/analysis/root.rs

@@ -520,6 +520,12 @@ impl DesignRoot {
         searcher.references
     }
 
+    pub fn find_all_references_in_source(&self, source: &Source, ent: EntRef) -> Vec<SrcPos> {
+        let mut searcher = FindAllReferences::new(self, ent);
+        let _ = self.search_source(source, &mut searcher);
+        searcher.references
+    }
+
     pub fn public_symbols<'a>(&'a self) -> Box<dyn Iterator<Item = EntRef<'a>> + 'a> {
         Box::new(self.libraries.values().flat_map(|library| {
             std::iter::once(self.arenas.get(library.id)).chain(library.units.values().flat_map(

vhdl_lang/src/project.rs

@@ -309,6 +309,10 @@ impl Project {
         self.root.find_all_references(ent)
     }
 
+    pub fn find_all_references_in_source(&self, source: &Source, ent: &AnyEnt) -> Vec<SrcPos> {
+        self.root.find_all_references_in_source(source, ent)
+    }
+
     /// Get source positions that are not resolved to a declaration
     /// This is used for development to test where the language server is blind
     pub fn find_all_unresolved(&self) -> (usize, Vec<SrcPos>) {

vhdl_ls/src/stdio_server.rs

@@ -190,6 +190,14 @@ impl ConnectionRpcChannel {
             }
             Err(request) => request,
         };
+        let request = match extract::<request::DocumentHighlightRequest>(request) {
+            Ok((id, params)) => {
+                let result = server.document_highlight(&params.text_document_position_params);
+                self.send_response(lsp_server::Response::new_ok(id, result));
+                return;
+            }
+            Err(request) => request,
+        };
         let request = match extract::<request::HoverRequest>(request) {
             Ok((id, params)) => {
                 let result = server.text_document_hover(&params.text_document_position_params);

vhdl_ls/src/vhdl_server.rs

@@ -182,6 +182,7 @@ impl VHDLServer {
             })),
             workspace_symbol_provider: Some(OneOf::Left(true)),
             document_symbol_provider: Some(OneOf::Left(true)),
+            document_highlight_provider: Some(OneOf::Left(true)),
             completion_provider: Some(CompletionOptions {
                 resolve_provider: Some(true),
                 trigger_characters: Some(trigger_chars),
@@ -681,6 +682,30 @@ impl VHDLServer {
         })
     }
 
+    pub fn document_highlight(
+        &mut self,
+        params: &TextDocumentPositionParams,
+    ) -> Option<Vec<DocumentHighlight>> {
+        let source = self
+            .project
+            .get_source(&uri_to_file_name(&params.text_document.uri))?;
+
+        let ent = self
+            .project
+            .find_declaration(&source, from_lsp_pos(params.position))?;
+
+        Some(
+            self.project
+                .find_all_references_in_source(&source, ent)
+                .iter()
+                .map(|pos| DocumentHighlight {
+                    range: to_lsp_range(pos.range()),
+                    kind: Some(DocumentHighlightKind::TEXT),
+                })
+                .collect(),
+        )
+    }
+
     pub fn workspace_symbol(
         &self,
         params: &WorkspaceSymbolParams,