[ VM / DDS ] Add --print-dtd-uri flag and launch DTD from the correct snapshot for AOT

This adds support for printing the DTD connection information to stdout
when --print-dtd-uri is passed.

This change also fixes an issue where DDS would fail to spawn an isolate
with the DTD snapshot when DDS was running in AOT mode. This means the
SDK must be shipped with both AppJIT and AOT DTD snapshots, at least
until dartdev is moved to run from AOT.

Fixes #55034

TEST=run_test.dart

Change-Id: I788ef9bfe76297a8d594992a2aac440ed9e2ecac
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/358541
Reviewed-by: Siva Annamalai <[email protected]>
Commit-Queue: Ben Konyi <[email protected]>
Reviewed-by: Kenzie Davisson <[email protected]>

Author: bkonyi

pkg/dartdev/lib/src/commands/run.dart

@@ -264,6 +264,13 @@ class RunCommand extends DartdevCommand {
             hide: !verbose,
             help: 'Enable hosting Observatory through the VM Service.',
             defaultsTo: true)
+        ..addFlag(
+          'print-dtd',
+          hide: !verbose,
+          help: 'Prints connection details for the Dart Tooling Daemon (DTD).'
+              'Useful for Dart DevTools extension authors working with DTD in the '
+              'extension development environment.',
+        )
         ..addFlag(
           'debug-dds',
           hide: true,

pkg/dartdev/lib/src/dds_runner.dart

@@ -24,25 +24,11 @@ class DDSRunner {
   }) async {
     final sdkDir = dirname(sdk.dart);
     final fullSdk = sdkDir.endsWith('bin');
-    String snapshotName = fullSdk
-        ? sdk.ddsAotSnapshot
-        : absolute(sdkDir, 'dds_aot.dart.snapshot');
-    String execName = sdk.dartAotRuntime;
-    // Check to see if the AOT snapshot and dartaotruntime are available.
-    // If not, fall back to running from the AppJIT snapshot.
-    //
-    // This can happen if:
-    //  - The SDK is built for IA32 which doesn't support AOT compilation
-    //  - We only have artifacts available from the 'runtime' build
-    //    configuration, which the VM SDK build bots frequently run from
-    if (!Sdk.checkArtifactExists(snapshotName, logError: false) ||
-        !Sdk.checkArtifactExists(sdk.dartAotRuntime, logError: false)) {
-      snapshotName =
-          fullSdk ? sdk.ddsSnapshot : absolute(sdkDir, 'dds.dart.snapshot');
-      if (!Sdk.checkArtifactExists(snapshotName)) {
-        return false;
-      }
-      execName = sdk.dart;
+    final execName = sdk.dart;
+    final snapshotName =
+        fullSdk ? sdk.ddsSnapshot : absolute(sdkDir, 'dds.dart.snapshot');
+    if (!Sdk.checkArtifactExists(snapshotName)) {
+      return false;
     }
 
     final process = await Process.start(

pkg/dartdev/test/commands/devtools_test.dart

@@ -18,6 +18,9 @@ final dartVMServiceRegExp = RegExp(
 final ddsStartedRegExp = RegExp(
   r'Started the Dart Development Service \(DDS\) at (http://127.0.0.1:.*)',
 );
+final dtdStartedRegExp = RegExp(
+  r'Serving the Dart Tooling Daemon at (ws://127.0.0.1:.*)',
+);
 final servingDevToolsRegExp = RegExp(
   r'Serving DevTools at (http://127.0.0.1:.*)',
 );
@@ -138,10 +141,54 @@ void devtools() {
     });
   });
 
+  Future<void> startDevTools({
+    String? vmServiceUri,
+    bool shouldStartDds = false,
+    bool shouldPrintDtd = false,
+  }) async {
+    final process = await p.start([
+      'devtools',
+      '--no-launch-browser',
+      if (shouldPrintDtd) '--print-dtd',
+      if (vmServiceUri != null) vmServiceUri,
+    ]);
+    process.stderr.transform(utf8.decoder).listen(print);
+
+    bool startedDds = false;
+    bool startedDtd = false;
+    final devToolsServedCompleter = Completer<void>();
+    late StreamSubscription sub;
+    sub = process.stdout
+        .transform<String>(utf8.decoder)
+        .transform<String>(const LineSplitter())
+        .listen((event) async {
+      print(event);
+      if (event.contains(ddsStartedRegExp)) {
+        startedDds = true;
+      } else if (event.contains(dtdStartedRegExp)) {
+        startedDtd = true;
+      } else if (event.contains(servingDevToolsRegExp)) {
+        await sub.cancel();
+        devToolsServedCompleter.complete();
+      }
+    });
+
+    await devToolsServedCompleter.future;
+    expect(startedDds, shouldStartDds);
+    expect(startedDtd, shouldPrintDtd);
+
+    // kill the process
+    process.kill();
+  }
+
+  test('prints DTD URI', () async {
+    p = project();
+    await startDevTools(shouldPrintDtd: true);
+  });
+
   group('spawns DDS integration', () {
     late TestProject targetProject;
     Process? targetProjectInstance;
-    Process? process;
 
     setUp(() {
       // NOTE: we don't use `project()` here since it registers a tear-down
@@ -163,9 +210,7 @@ Future<void> main() async {
 
     tearDown(() {
       targetProjectInstance?.kill();
-      process?.kill();
       targetProjectInstance = null;
-      process = null;
       targetProject.dispose();
       p.dispose();
     });
@@ -199,40 +244,6 @@ Future<void> main() async {
       return await serviceUriCompleter.future;
     }
 
-    Future<void> startDevTools({
-      required String vmServiceUri,
-      required bool shouldStartDds,
-    }) async {
-      process = await p.start([
-        'devtools',
-        '--no-launch-browser',
-        vmServiceUri,
-      ]);
-      process!.stderr.transform(utf8.decoder).listen(print);
-
-      bool startedDds = false;
-      final devToolsServedCompleter = Completer<void>();
-      late StreamSubscription sub;
-      sub = process!.stdout
-          .transform<String>(utf8.decoder)
-          .transform<String>(const LineSplitter())
-          .listen((event) async {
-        if (event.contains(ddsStartedRegExp)) {
-          startedDds = true;
-        } else if (event.contains(servingDevToolsRegExp)) {
-          await sub.cancel();
-          devToolsServedCompleter.complete();
-        }
-      });
-
-      await devToolsServedCompleter.future;
-      expect(startedDds, shouldStartDds);
-
-      // kill the process
-      process!.kill();
-      process = null;
-    }
-
     for (final disableAuthCodes in const [true, false]) {
       final authCodesEnabledStr = disableAuthCodes ? 'disabled' : 'enabled';
       test('with auth codes $authCodesEnabledStr', () async {