register cuda language activation event and activate for .cuh files

[ptaylor]

A similar PR has been submitted to the vscode-cpptools repo to enable debugging CUDA files via cuda-gdb with the official Microsoft VSCode C++ plugin: https://github.com/microsoft/vscode-cpptools/pull/4585

[hokein]

Thanks for the patch.

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

92

I think we could simplify the code, we could move this part to the package.json under the contributes umbrella, something like

"contributes": {
      "languages": [
          {
              "id": "cuda",
              "filenamePatterns": [
                  "**/*.{cu}",
                  "**/*.{cuh}",
              ],
          }
      ]

then in the extension.ts, we only need an entry { scheme: 'file', language: 'cuda' } when initailizing the clientOptions.

[ptaylor]

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

92

Yes that's an option. I chose this approach to stay consistent with the current behavior, because vscode-clangd can do CUDA intellisense and refactoring, it doesn't contribute the CUDA grammar definitions for syntax highlighting.

The VSCode docs aren't clear on whether multiple extensions can contribute separate features for the same language, or what happens when two plugins both contribute languages with the same languageId.

[hokein]

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

92

I chose this approach to stay consistent with the current behavior.

Yes, I was not ware of this approach before.

The VSCode docs aren't clear on whether multiple extensions can contribute separate features for the same language, or what happens when two plugins both contribute languages with the same languageId.

The vscode doc says ontributes.languages can enrich the knowledge about vscode, but doesn't mention about what if there are multiple extensions contribute for the same language, but from our experience (clangd extension also contributes to cpp language for taking some file patterns into account), it seems no problem so far.

Anyway, I'm also fine with the current approach.

103

I'd drop A working ...., I don't know much about vscode-cudacpp. But in theory, clangd extension will work with any extension which provides the cuda language definition.

[ptaylor]

• add package.json entry to contribute cuda language id
• remove extra cuda file patterns, update comments

[ptaylor]

• fix package.json whitespace

[hokein]

sorry for the delay, looks good, one more nit.

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

101

This comment seems not correct anymore, I'd just drop it, or rephrase like VSCode does not have CUDA as a supported language yet, but our extension does.

[ptaylor]

drop comment about vscode cuda syntax highlighting

clang-tools-extra/clangd/clients/clangd-vscode/package.json

"keywords": [
         "C++",
         "LSP",
         "Clangd",
         "LLVM"
     ],
     "activationEvents": [
         "onLanguage:c",
         "onLanguage:cpp",
+        "onLanguage:cuda",
         "onLanguage:objective-c",
         "onLanguage:objective-cpp",
         "onCommand:clangd-vscode.activate"
     ],
     "main": "./out/src/extension",
     "scripts": {
         "vscode:prepublish": "tsc -p ./",
         "compile": "tsc -watch -p ./",

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

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.
-  const cudaFilePattern: string = '**/*.{' + [ 'cu' ].join() + '}';
+  // *not* load itself automatically on '.cu' and '.cuh' files.
+  const cudaFilePatterns: {scheme: string, pattern: string}[] = [
+    {scheme : 'file', pattern : '**/*.{cu}'},
+    {scheme : 'file', pattern : '**/*.{cuh}'}
+  ];
   const clientOptions: vscodelc.LanguageClientOptions = {
         // Register the server for c-family and cuda files.
         documentSelector: [
             { scheme: 'file', language: 'c' },
             { scheme: 'file', language: 'cpp' },
+            // Optimistically register an activation event for the 'cuda'
+            // language id. This should be forwards-compatible if VSCode
+            // starts shipping CUDA language support. A working 'cuda'
+            // language definition is provided by kriegalex.vscode-cudacpp.
+            // This handler ensures clangd activates if the vscode-cudacpp
+            // plugin is installed and activated.
+            // @see https://github.com/kriegalex/vscode-cuda
+            // @see https://marketplace.visualstudio.com/items?itemName=kriegalex.vscode-cudacpp
+            { scheme: 'file', language: 'cuda' },
             { scheme: 'file', language: 'objective-c'},
             { scheme: 'file', language: 'objective-cpp'},
-            { scheme: 'file', pattern: cudaFilePattern },
+            // Also add the '.cu' and '.cuh' patterns
+            ...cudaFilePatterns
         ],
         synchronize: !syncFileEvents ? undefined : {
         // FIXME: send sync file events when clangd provides implemenatations.
         },
         initializationOptions: { clangdFileStatus: true },
         // Do not switch to output window when clangd returns output
         revealOutputChannelOn: vscodelc.RevealOutputChannelOn.Never
     };
 
   const clangdClient = new ClangdLanguageClient('Clang Language Server',
                                                 serverOptions, clientOptions);
   if (getConfig<boolean>('semanticHighlighting')) {
     const semanticHighlightingFeature =
         new semanticHighlighting.SemanticHighlightingFeature(clangdClient,
                                                              context);
     context.subscriptions.push(
         vscode.Disposable.from(semanticHighlightingFeature));
     clangdClient.registerFeature(semanticHighlightingFeature);
   }
   console.log('Clang Language Server is now active!');
   context.subscriptions.push(clangdClient.start());
   context.subscriptions.push(vscode.commands.registerCommand(
       'clangd-vscode.switchheadersource', async () => {
         const uri =
             vscode.Uri.file(vscode.window.activeTextEditor.document.fileName);