First pass at semantic highlighting.

It is disabled by default.

src/command_line.cc

@@ -143,6 +143,51 @@ void EmitInactiveLines(WorkingFile* working_file,
       IpcId::CqueryPublishInactiveRegions, out);
 }
 
+void EmitSemanticHighlighting(QueryDatabase* db,
+                              WorkingFile* working_file,
+                              QueryFile* file) {
+  auto map_symbol_kind_to_symbol_type = [](SymbolKind kind) {
+    switch (kind) {
+      case SymbolKind::Type:
+        return Out_CqueryPublishSemanticHighlighting::SymbolType::Type;
+      case SymbolKind::Func:
+        return Out_CqueryPublishSemanticHighlighting::SymbolType::Function;
+      case SymbolKind::Var:
+        return Out_CqueryPublishSemanticHighlighting::SymbolType::Variable;
+      default:
+        assert(false);
+        return Out_CqueryPublishSemanticHighlighting::SymbolType::Variable;
+    }
+  };
+
+  // Group symbols together.
+  std::unordered_map<SymbolIdx, NonElidedVector<lsRange>> grouped_symbols;
+  for (SymbolRef sym : file->def->all_symbols) {
+    if (sym.idx.kind == SymbolKind::Var) {
+      QueryVar* var = &db->vars[sym.idx.idx];
+      if (!var->def)
+        continue;
+      if (!var->def->is_local)
+        continue;
+    }
+    optional<lsRange> loc = GetLsRange(working_file, sym.loc.range);
+    if (loc)
+      grouped_symbols[sym.idx].push_back(*loc);
+  }
+
+  // Publish.
+  Out_CqueryPublishSemanticHighlighting out;
+  out.params.uri = lsDocumentUri::FromPath(working_file->filename);
+  for (auto& entry : grouped_symbols) {
+    Out_CqueryPublishSemanticHighlighting::Symbol symbol;
+    symbol.type = map_symbol_kind_to_symbol_type(entry.first.kind);
+    symbol.ranges = entry.second;
+    out.params.symbols.push_back(symbol);
+  }
+  IpcManager::instance()->SendOutMessageToClient(
+      IpcId::CqueryPublishSemanticHighlighting, out);
+}
+
 optional<int> FindIncludeLine(const std::vector<std::string>& lines,
                               const std::string& full_include_line) {
   //
@@ -1286,6 +1331,18 @@ bool QueryDb_ImportMain(Config* config,
                                        return value.path;
                                      }));
 
+    // Update semantic highlighting.
+    for (auto& updated_file : response->update.files_def_update) {
+      WorkingFile* working_file =
+          working_files->GetFileByFilename(updated_file.path);
+      if (working_file) {
+        QueryFileId file_id =
+            db->usr_to_file[LowerPathIfCaseInsensitive(working_file->filename)];
+        QueryFile* file = &db->files[file_id.id];
+        EmitSemanticHighlighting(db, working_file, file);
+      }
+    }
+
     // Mark the files as being done in querydb stage after we apply the index
     // update.
     for (auto& updated_file : response->update.files_def_update)
@@ -1774,8 +1831,10 @@ bool QueryDbMainLoop(Config* config,
 
         QueryFile* file = nullptr;
         FindFileOrFail(db, nullopt, path, &file);
-        if (file && file->def)
+        if (file && file->def) {
           EmitInactiveLines(working_file, file->def->inactive_regions);
+          EmitSemanticHighlighting(db, working_file, file);
+        }
 
         time.ResetAndPrint(
             "[querydb] Loading cached index file for DidOpen (blocks "
@@ -2743,8 +2802,11 @@ bool QueryDbMainLoop(Config* config,
         // TODO: We need to move this to a separate request, as the user may
         // have turned code lens off (ie, a custom DidView notification).
         if (file && file->def) {
-          EmitInactiveLines(working_files->GetFileByFilename(file->def->path),
+          WorkingFile* working_file =
-                            file->def->inactive_regions);
+              working_files->GetFileByFilename(file->def->path);
+          EmitInactiveLines(working_file, file->def->inactive_regions);
+          // Do not emit semantic highlighting information here, as it has not
+          // been updated.
         }
 
         break;

src/ipc.cc

@@ -51,6 +51,8 @@ const char* IpcIdToString(IpcId id) {
 
     case IpcId::CqueryPublishInactiveRegions:
       return "$cquery/publishInactiveRegions";
+    case IpcId::CqueryPublishSemanticHighlighting:
+      return "$cquery/publishSemanticHighlighting";
 
     case IpcId::CqueryFreshenIndex:
       return "$cquery/freshenIndex";

src/ipc.h

@@ -32,6 +32,7 @@ enum class IpcId : int {
 
   // Custom notifications
   CqueryPublishInactiveRegions,
+  CqueryPublishSemanticHighlighting,
 
   // Custom messages
   CqueryFreshenIndex,

src/language_server_api.h

@@ -1480,6 +1480,32 @@ struct Out_CquerySetInactiveRegion
 MAKE_REFLECT_STRUCT(Out_CquerySetInactiveRegion::Params, uri, inactiveRegions);
 MAKE_REFLECT_STRUCT(Out_CquerySetInactiveRegion, jsonrpc, method, params);
 
+struct Out_CqueryPublishSemanticHighlighting
+    : public lsOutMessage<Out_CqueryPublishSemanticHighlighting> {
+  enum class SymbolType { Type = 0, Function, Variable };
+  struct Symbol {
+    SymbolType type;
+    NonElidedVector<lsRange> ranges;
+  };
+  struct Params {
+    lsDocumentUri uri;
+    NonElidedVector<Symbol> symbols;
+  };
+  std::string method = "$cquery/publishSemanticHighlighting";
+  Params params;
+};
+MAKE_REFLECT_TYPE_PROXY(Out_CqueryPublishSemanticHighlighting::SymbolType, int);
+MAKE_REFLECT_STRUCT(Out_CqueryPublishSemanticHighlighting::Symbol,
+                    type,
+                    ranges);
+MAKE_REFLECT_STRUCT(Out_CqueryPublishSemanticHighlighting::Params,
+                    uri,
+                    symbols);
+MAKE_REFLECT_STRUCT(Out_CqueryPublishSemanticHighlighting,
+                    jsonrpc,
+                    method,
+                    params);
+
 struct Ipc_CqueryFreshenIndex : public IpcMessage<Ipc_CqueryFreshenIndex> {
   const static IpcId kIpcId = IpcId::CqueryFreshenIndex;
   lsRequestId id;

src/query.h

@@ -74,6 +74,7 @@ struct SymbolIdx {
   }
 };
 MAKE_REFLECT_STRUCT(SymbolIdx, kind, idx);
+MAKE_HASHABLE(SymbolIdx, t.kind, t.idx);
 
 struct SymbolRef {
   SymbolIdx idx;