Implement not supported message for arm platform and alpine containers

Extension/src/cppTools1.ts

@@ -4,7 +4,7 @@
  * ------------------------------------------------------------------------------------------ */
 'use strict';
 
-import { CustomConfigurationProvider, Version, CppToolsApi } from 'vscode-cpptools';
+import { CustomConfigurationProvider, Version, CppToolsApi, CppToolsExtension } from 'vscode-cpptools';
 import { CppToolsTestApi, CppToolsTestHook, CppToolsTestExtension } from 'vscode-cpptools/out/testApi';
 import { CppTools } from './cppTools';
 
@@ -63,3 +63,35 @@ export class CppTools1 implements CppToolsTestApi, CppToolsTestExtension {
         return this.BackupApi.getTestHook();
     }
 }
+
+/**
+ * This is an empty implementation of the API. Used when the extension is activated on
+ * an unsupported platform.
+ */
+export class NullCppTools implements CppToolsApi, CppToolsExtension {
+    private version: Version;
+
+    getApi(version: Version): CppToolsApi {
+        this.version = version;
+        return this;
+    }
+
+    getVersion(): Version {
+        return this.version;
+    }
+
+    registerCustomConfigurationProvider(provider: CustomConfigurationProvider): void {
+    }
+
+    notifyReady(provider: CustomConfigurationProvider): void {
+    }
+
+    didChangeCustomConfiguration(provider: CustomConfigurationProvider): void {
+    }
+
+    didChangeCustomBrowseConfiguration(provider: CustomConfigurationProvider): void {
+    }
+
+    dispose(): void {
+    }
+}

Extension/src/main.ts

@@ -20,7 +20,7 @@ import { PackageManager, PackageManagerError, IPackage } from './packageManager'
 import { PersistentState } from './LanguageServer/persistentState';
 import { getInstallationInformation, InstallationInformation, setInstallationStage, setInstallationType, InstallationType } from './installationInformation';
 import { Logger, getOutputChannelLogger, showOutputChannel } from './logger';
-import { CppTools1 } from './cppTools1';
+import { CppTools1, NullCppTools } from './cppTools1';
 
 const releaseNotesVersion: number = 5;
 const cppTools: CppTools1 = new CppTools1();
@@ -29,6 +29,17 @@ let reloadMessageShown: boolean = false;
 let disposables: vscode.Disposable[] = [];
 
 export async function activate(context: vscode.ExtensionContext): Promise<CppToolsApi & CppToolsExtension> {
+    let errMsg: string = "";
+    if (process.arch !== 'x32' && process.arch !== 'x64') {
+        errMsg = "Architecture " + String(process.arch) + " is not supported. ";
+    } else if (process.platform === 'linux' && fs.existsSync('/etc/alpine-release')) {
+        errMsg = "Alpine containers are not supported. ";
+    }
+    if (errMsg) {
+        vscode.window.showErrorMessage(errMsg);
+        return new NullCppTools();
+    }
+
     util.setExtensionContext(context);
     initializeTemporaryCommandRegistrar();
     Telemetry.activate();