Add dart2wasm support to pkg/dynamic_modules.

Also introduce some tests that include some potential pitfalls in the  wasm implementation.

Change-Id: I904930db992d45414b6e214b68ca542ca29419e4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/400901
Reviewed-by: Sigmund Cherem <[email protected]>
Commit-Queue: Nate Biggs <[email protected]>

Author: natebiggs

pkg/dynamic_modules/test/common/testing.dart

@@ -32,7 +32,9 @@ Future<Object?> load(String moduleName,
     }
     return loadModuleFromBytes(bytes);
   }
-  throw "load is not implemented for dart2wasm";
+  // Dart2wasm implementation
+  return loadModuleFromUri(
+      Uri(scheme: '', path: 'modules/${moduleName}_module1.wasm'));
 }
 
 /// Notify the test harness that the test has run to completion.

pkg/dynamic_modules/test/data/core_api/dynamic_interface.yaml

@@ -33,7 +33,6 @@ callable:
     member: 'get:current'
   - library: 'dart:core'
     class: 'Iterator'
-  - library: 'dart:core'
 
   # Needed to support creating list literals
   - library: 'dart:core'

pkg/dynamic_modules/test/data/multiple_classes/dynamic_interface.yaml

@@ -0,0 +1,26 @@
+# Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+extendable:
+  # TODO(sigmund): This should be included by default
+  - library: 'dart:core'
+    class: 'Object'
+  - library: 'modules/common.dart'
+    class: 'A'
+
+callable:
+    # TODO(sigmund): This should be included by default
+  - library: 'dart:core'
+    class: 'Object'
+  - library: 'dart:core'
+    class: 'pragma'
+    member: '_'
+  - library: 'modules/common.dart'
+    class: 'A'
+    member: 'getString'
+
+can-be-overridden:
+  - library: 'modules/common.dart'
+    class: 'A'
+    member: 'getString'

pkg/dynamic_modules/test/data/multiple_classes/main.dart

@@ -0,0 +1,18 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:expect/expect.dart';
+
+import '../../common/testing.dart' as helper;
+import 'modules/common.dart';
+
+// It is an error to load a module that provides a second definition for
+// a library that already exists in the application.
+main() async {
+  final a1 = await helper.load('entry1.dart') as A;
+  final a2 = await helper.load('entry2.dart') as A;
+  Expect.equals(a1.getString(), 'B');
+  Expect.equals(a2.getString(), 'C');
+  helper.done();
+}

pkg/dynamic_modules/test/data/multiple_classes/modules/common.dart

@@ -0,0 +1,7 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+abstract class A {
+  String getString();
+}

pkg/dynamic_modules/test/data/multiple_classes/modules/entry1.dart

@@ -0,0 +1,13 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'common.dart';
+
+class B implements A {
+  @override
+  String getString() => 'B';
+}
+
+@pragma('dyn-module:entry-point')
+Object? entrypoint() => B();

pkg/dynamic_modules/test/data/multiple_classes/modules/entry2.dart

@@ -0,0 +1,13 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'common.dart';
+
+class C implements A {
+  @override
+  String getString() => 'C';
+}
+
+@pragma('dyn-module:entry-point')
+Object? entrypoint() => C();

pkg/dynamic_modules/test/runner/dart2wasm.dart

@@ -0,0 +1,123 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Implementation of the [TargetExecutor] for dart2wasm.
+library;
+
+import 'dart:io';
+import '../common/testing.dart' as helper;
+
+import 'model.dart';
+import 'util.dart';
+import 'target.dart';
+
+/// Logic to build and execute dynamic modules in dart2wasm.
+///
+/// In particular:
+///   * The initial app is built as a regular dart2wasm target, except that
+///     a dynamic interface is used to define hooks that dynamic modules update
+///     when loaded. The dynamic interface also prevents treeshaking of some
+///     entities.
+///   * For dynamic modules, dart2wasm validates that the module only accesses
+///     what's allowed by the dynamic interface.
+///   * For dynamic modules, dart2wasm exports a specific entry point function.
+class Dart2wasmExecutor implements TargetExecutor {
+  static const rootScheme = 'dev-dart-app';
+  late final bool _shouldCleanup;
+  late final Directory _tmp;
+  final Logger _logger;
+
+  Dart2wasmExecutor(this._logger) {
+    /// Allow using an environment variable to run tests on a fixed directory.
+    /// This prevents the directory from getting deleted too.
+    var path = Platform.environment['TMP_DIR'] ?? '';
+    if (path.isEmpty) {
+      _tmp = Directory.systemTemp.createTempSync('_dynamic_module-');
+      _shouldCleanup = false;
+    } else {
+      _tmp = Directory(path);
+      if (!_tmp.existsSync()) _tmp.createSync();
+      _shouldCleanup = false;
+    }
+  }
+
+  @override
+  Future<void> suiteComplete() async {
+    if (!_shouldCleanup) return;
+    try {
+      _tmp.delete(recursive: true);
+    } on FileSystemException {
+      // Windows bots sometimes fail to delete folders, and can make tests
+      // flaky. It is OK in those cases to leak some files in the tmp folder,
+      // these will eventually be cleared when a new bot instance is created.
+      _logger.warning('Error trying to delete $_tmp');
+    }
+  }
+
+  Future _compile(
+      String testName, String source, Uri sourceDir, bool isMain) async {
+    var testDir = _tmp.uri.resolve(testName).toFilePath();
+    var args = [
+      '--packages=${repoRoot.toFilePath()}/.dart_tool/package_config.json',
+      '--multi-root=${sourceDir.resolve('../../')}',
+      '--multi-root-scheme=$rootScheme',
+      // This is required while binaryen lacks support for partially closed
+      // world optimizations.
+      '-O0',
+      '--extra-compiler-option=--dynamic-module-main=main.dart.dill',
+      if (isMain)
+        '--extra-compiler-option=--dynamic-module-interface='
+            '$rootScheme:/data/$testName/dynamic_interface.yaml',
+      '$rootScheme:/data/$testName/$source',
+      '$source.wasm',
+    ];
+    await runProcess(compileBenchmark.toFilePath(), args, testDir, _logger,
+        'compile $testName/$source');
+  }
+
+  @override
+  Future compileApplication(DynamicModuleTest test) async {
+    _ensureDirectory(test.name);
+    _logger.info('Compile ${test.name} app');
+    await _compile(test.name, test.main, test.folder, true);
+  }
+
+  @override
+  Future compileDynamicModule(DynamicModuleTest test, String name) async {
+    _logger.info('Compile module ${test.name}.$name');
+    _ensureDirectory(test.name);
+    await _compile(test.name, test.dynamicModules[name]!, test.folder, false);
+  }
+
+  @override
+  Future executeApplication(DynamicModuleTest test) async {
+    _logger.info('Execute ${test.name}');
+    _ensureDirectory(test.name);
+
+    // We generate a self contained script that loads necessary preambles,
+    // dart2wasm module loader, the necessary modules (the SDK and the main
+    // module), and finally launches the app.
+    var testDir = _tmp.uri.resolve('${test.name}/');
+    var result = await runProcess(
+        runBenchmark.toFilePath(),
+        ['${test.main}.wasm'],
+        testDir.toFilePath(),
+        _logger,
+        'run_benchmark ${test.main}.wasm');
+    var stdout = result.stdout as String;
+    if (!stdout.contains(helper.successToken)) {
+      _logger.error('Error: test didn\'t complete as expected.\n'
+          'Make sure the test finishes and calls `helper.done()`.\n'
+          'Test output:\n$stdout');
+      throw Exception('missing helper.done');
+    }
+  }
+
+  void _ensureDirectory(String name) {
+    var dir = Directory.fromUri(_tmp.uri.resolve(name));
+    if (!dir.existsSync()) {
+      dir.createSync();
+    }
+  }
+}

pkg/dynamic_modules/test/runner/main.dart

@@ -10,6 +10,7 @@ import 'dart:io';
 import 'package:args/args.dart';
 
 import 'aot.dart';
+import 'dart2wasm.dart';
 import 'ddc.dart';
 import 'load.dart';
 import 'model.dart';
@@ -55,7 +56,7 @@ void main(List<String> args) async {
     executor = switch (target) {
       Target.ddc => DdcExecutor(logger),
       Target.aot => AotExecutor(logger),
-      Target.dart2wasm => UnimplementedExecutor(logger),
+      Target.dart2wasm => Dart2wasmExecutor(logger),
     };
 
     final results = <DynamicModuleTestResult>[];

pkg/dynamic_modules/test/runner/util.dart

@@ -90,6 +90,13 @@ Uri aotRuntimeBin = buildRootUri
     .resolve(useProduct ? 'dartaotruntime_product' : 'dartaotruntime');
 Uri vmPlatformDill = buildRootUri.resolve('vm_platform_strong.dill');
 
+Uri dart2wasmSnapshot =
+    _dartBin.resolve('snapshots/dart2wasm_product.snapshot');
+Uri dart2wasmPlatformDill = buildRootUri.resolve('dart2wasm_platform.dill');
+Uri dart2wasmLibrariesSpec = repoRoot.resolve('sdk/lib/libraries.json');
+Uri compileBenchmark = repoRoot.resolve('pkg/dart2wasm/tool/compile_benchmark');
+Uri runBenchmark = repoRoot.resolve('pkg/dart2wasm/tool/run_benchmark');
+
 // Encodes test results in the format expected by Dart's CI infrastructure.
 class TestResultOutcome {
   // This encoder must generate each output element on its own line.