[clangd] Don't restart clangd in vscode extension.

[hokein]

Summary

This would make the life of tracking/reporting crashes easier, and
restarting clangd doesn't help as file state is usually broken.

[hokein]

Fix space.

[hokein]

update

clangd/clients/clangd-vscode/src/extension.ts

 import * as vscode from 'vscode';
 import * as vscodelc from 'vscode-languageclient';
 import { realpathSync } from 'fs';
 
 /**
  * Method to get workspace configuration option
  * @param option name of the option (e.g. for clangd.path should be path)
  * @param defaultValue default value to return if option is not set
  */
 function getConfig<T>(option: string, defaultValue?: any): T {
     const config = vscode.workspace.getConfiguration('clangd');
     return config.get<T>(option, defaultValue);
 }
 
+class NoRestartErrorHandler implements vscodelc.ErrorHandler {
+    // Mirror the implementation of DefaultErrorHandler which is not exposed in
+    // vscode-languageclient.
+    public error(_error: Error, _message: vscodelc.Message, count: number): vscodelc.ErrorAction {
+        if (count && count <= 3) {
+            return vscodelc.ErrorAction.Continue;
+        }
+        return vscodelc.ErrorAction.Shutdown;
+    }
+    public closed(): vscodelc.CloseAction {
+        // The default implementation will restarts clangd up to 5 times if clangd
+        // crashes. We don't restart clangd -- this'd make the life of tracking/reporting
+        // crashes easier, and sometimes restart doesn't help as the file state
+        // is usually broken (files are not opened, etc).
+        vscode.window.showErrorMessage(`The clangd crashed, please reload the window to restart.`);
+        return vscodelc.CloseAction.DoNotRestart;
+    }
+}
+
 namespace SwitchSourceHeaderRequest {
 export const type =
     new vscodelc.RequestType<vscodelc.TextDocumentIdentifier, string|undefined,
                              void, void>('textDocument/switchSourceHeader');
 }
 
 class FileStatus {
     private statuses = new Map<string, any>();
const clientOptions: vscodelc.LanguageClientOptions = {
         // rather than its filesystem path.
         // FIXME: remove this once clangd knows enough about bazel to resolve the
         // symlinks where needed (or if this causes problems for other workflows).
         uriConverters: {
             code2Protocol: (value: vscode.Uri) => value.toString(),
             protocol2Code: (value: string) =>
                 vscode.Uri.file(realpathSync(vscode.Uri.parse(value).fsPath))
         },
+        errorHandler: new NoRestartErrorHandler(),
         // Do not switch to output window when clangd returns output
         revealOutputChannelOn: vscodelc.RevealOutputChannelOn.Never
     };
 
   const clangdClient = new vscodelc.LanguageClient('Clang Language Server', serverOptions, clientOptions);
   console.log('Clang Language Server is now active!');
   context.subscriptions.push(clangdClient.start());
   context.subscriptions.push(vscode.commands.registerCommand(