[clangd][vscode] Add a flag to enable semantic highlighting in clangd

Reviewers: ilya-biryukov

Subscribers: MaskRay, jkorous, arphaman, kadircet, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67096

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@371038 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clangd/clients/clangd-vscode/package.json b/clangd/clients/clangd-vscode/package.json
index 52e5914..c2ef3f8 100644
--- a/clangd/clients/clangd-vscode/package.json
+++ b/clangd/clients/clangd-vscode/package.json
@@ -89,6 +89,11 @@
                 "clangd.trace": {
                     "type": "string",
                     "description": "Names a file that clangd should log a performance trace to, in chrome trace-viewer JSON format."
+                },
+                "clangd.semanticHighlighting": {
+                    "type": "boolean",
+                    "default": "false",
+                    "description": "Enable semantic highlighting in clangd"
                 }
             }
         },
diff --git a/clangd/clients/clangd-vscode/src/extension.ts b/clangd/clients/clangd-vscode/src/extension.ts
index 4cd7b0e..330cf7a 100644
--- a/clangd/clients/clangd-vscode/src/extension.ts
+++ b/clangd/clients/clangd-vscode/src/extension.ts
@@ -109,12 +109,14 @@
 
   const clangdClient = new ClangdLanguageClient('Clang Language Server',
                                                 serverOptions, clientOptions);
-  const semanticHighlightingFeature =
+  if (getConfig<boolean>('semanticHighlighting')) {
+    const semanticHighlightingFeature =
       new semanticHighlighting.SemanticHighlightingFeature(clangdClient,
-                                                           context);
-  context.subscriptions.push(
+        context);
+    context.subscriptions.push(
       vscode.Disposable.from(semanticHighlightingFeature));
-  clangdClient.registerFeature(semanticHighlightingFeature);
+    clangdClient.registerFeature(semanticHighlightingFeature);
+  }
   console.log('Clang Language Server is now active!');
   context.subscriptions.push(clangdClient.start());
   context.subscriptions.push(vscode.commands.registerCommand(