[clangd] Add .cu files to VSCode extension

Summary:
clangd should be able to handle those with a proper compilation
database. However, users using 'nvcc' might start seeing spurious errors
in '.cu' files after this change.

My plan is to land and release this, but be ready to revert in
case of negative user feedback.

Reviewers: hokein

Reviewed By: hokein

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

Tags: #clang

Differential Revision: https://reviews.llvm.org/D59759

llvm-svn: 356916

clang-tools-extra/clangd/clients/clangd-vscode/src/extension.ts

@@ -68,8 +68,18 @@ export function activate(context: vscode.ExtensionContext) {
     }
     const serverOptions: vscodelc.ServerOptions = clangd;
 
+    // Note that CUDA ('.cu') files are special. When opening files of all other
+    // extensions, VSCode would load clangd automatically. This is achieved by
+    // having a corresponding 'onLanguage:...' activation event in package.json.
+    // However, VSCode does not have CUDA as a supported language yet, so we
+    // cannot add a corresponding activationEvent for CUDA files and clangd will
+    // *not* load itself automatically on '.cu' files. When any of the files
+    // with other extensions are open, clangd will load itself and will also
+    // work on '.cu' files.
     const filePattern: string = '**/*.{' +
-        ['cpp', 'c', 'cc', 'cxx', 'c++', 'm', 'mm', 'h', 'hh', 'hpp', 'hxx', 'inc'].join() + '}';
+        ['cpp', 'c', 'cc', 'cu', 'cxx', 'c++', 'm', 'mm',
+            'h', 'hh', 'hpp', 'hxx', 'inc'].join()
+        + '}';
     const clientOptions: vscodelc.LanguageClientOptions = {
         // Register the server for C/C++ files
         documentSelector: [{ scheme: 'file', pattern: filePattern }],