[dart2wasm] Copy VM's map and set factory transformers

osa1 · Commit Queue · commit cf9f45f1d4bd · 2025-03-19T08:10:16.000-07:00
Transform factory calls to default map and set classes to the constructor calls to the classes to improve kernel. Also remove some redundant null checks in VM's transformer. `source_map_simple_optimized_test.dart` is updated: with improved kernel wasm-opt now eliminates the `testMain` function, so the stack trace doesn't mention it. Fixes #60343. Tested: minor refactoring in VM doesn't need testing. Wasm tested with existing tests. Change-Id: Ie448d1374ff0e1b278859f22bc250899e0e4cfd0 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416640 Reviewed-by: Martin Kustermann <kustermann@google.com> Commit-Queue: Ömer Ağacan <omersa@google.com>
diff --git a/pkg/dart2wasm/lib/factory_specializer.dart b/pkg/dart2wasm/lib/factory_specializer.dart
@@ -0,0 +1,41 @@
+// Copyright (c) 2025, 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:kernel/core_types.dart';
+import 'package:kernel/kernel.dart';
+
+import 'list_factory_specializer.dart';
+import 'map_factory_specializer.dart';
+import 'set_factory_specializer.dart';
+
+typedef SpecializerTransformer = TreeNode Function(StaticInvocation node);
+
+abstract class BaseSpecializer {
+  // Populated in constructors of subclasses.
+  final Map<Member, SpecializerTransformer> transformers = {};
+}
+
+class FactorySpecializer extends BaseSpecializer {
+  final ListFactorySpecializer _listFactorySpecializer;
+  final SetFactorySpecializer _setFactorySpecializer;
+  final MapFactorySpecializer _mapFactorySpecializer;
+
+  FactorySpecializer(CoreTypes coreTypes)
+      : _listFactorySpecializer = ListFactorySpecializer(coreTypes),
+        _setFactorySpecializer = SetFactorySpecializer(coreTypes),
+        _mapFactorySpecializer = MapFactorySpecializer(coreTypes) {
+    transformers.addAll(_listFactorySpecializer.transformers);
+    transformers.addAll(_setFactorySpecializer.transformers);
+    transformers.addAll(_mapFactorySpecializer.transformers);
+  }
+
+  TreeNode transformStaticInvocation(StaticInvocation invocation) {
+    final target = invocation.target;
+    final transformer = transformers[target];
+    if (transformer != null) {
+      return transformer(invocation);
+    }
+    return invocation;
+  }
+}
diff --git a/pkg/dart2wasm/lib/list_factory_specializer.dart b/pkg/dart2wasm/lib/list_factory_specializer.dart
@@ -21,7 +21,7 @@ import 'package:kernel/core_types.dart' show CoreTypes;
 /// ```
 class ListFactorySpecializer {
   final Map<Member, StaticInvocation Function(StaticInvocation node)>
-      _transformers = {};
+      transformers = {};
 
   final Procedure _fixedListEmptyFactory;
   final Procedure _fixedListFactory;
@@ -58,14 +58,14 @@ class ListFactorySpecializer {
             .getProcedure('dart:_list', 'ModifiableFixedLengthList', 'filled'),
         _fixedListGenerateFactory = coreTypes.index.getProcedure(
             'dart:_list', 'ModifiableFixedLengthList', 'generate') {
-    _transformers[_listFilledFactory] = _transformListFilledFactory;
-    _transformers[_listEmptyFactory] = _transformListEmptyFactory;
-    _transformers[_listGenerateFactory] = _transformListGenerateFactory;
+    transformers[_listFilledFactory] = _transformListFilledFactory;
+    transformers[_listEmptyFactory] = _transformListEmptyFactory;
+    transformers[_listGenerateFactory] = _transformListGenerateFactory;
   }
 
   StaticInvocation transformStaticInvocation(StaticInvocation invocation) {
     final target = invocation.target;
-    final transformer = _transformers[target];
+    final transformer = transformers[target];
     if (transformer != null) {
       return transformer(invocation);
     }
diff --git a/pkg/dart2wasm/lib/map_factory_specializer.dart b/pkg/dart2wasm/lib/map_factory_specializer.dart
@@ -0,0 +1,37 @@
+// Copyright (c) 2025, 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:kernel/ast.dart';
+import 'package:kernel/core_types.dart';
+
+import 'factory_specializer.dart';
+
+/// Replaces invocation of Map factory constructors with factories of
+/// Wasm-specific classes.
+///
+///     new LinkedHashMap<K, V>() => new DefaultMap<K, V>()
+class MapFactorySpecializer extends BaseSpecializer {
+  final Procedure _linkedHashMapDefaultFactory;
+  final Constructor _internalLinkedHashMapConstructor;
+
+  MapFactorySpecializer(CoreTypes coreTypes)
+      : _linkedHashMapDefaultFactory = coreTypes.index
+            .getProcedure('dart:collection', 'LinkedHashMap', ''),
+        _internalLinkedHashMapConstructor = coreTypes.index
+            .getConstructor('dart:_compact_hash', 'DefaultMap', '') {
+    transformers.addAll({_linkedHashMapDefaultFactory: transformLinkedHashMap});
+  }
+
+  TreeNode transformLinkedHashMap(StaticInvocation node) {
+    final args = node.arguments;
+    if (args.named.isEmpty) {
+      return ConstructorInvocation(
+        _internalLinkedHashMapConstructor,
+        Arguments([], types: args.types),
+      )..fileOffset = node.fileOffset;
+    }
+
+    return node;
+  }
+}
diff --git a/pkg/dart2wasm/lib/set_factory_specializer.dart b/pkg/dart2wasm/lib/set_factory_specializer.dart
@@ -0,0 +1,38 @@
+// Copyright (c) 2025, 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:kernel/ast.dart';
+import 'package:kernel/core_types.dart' show CoreTypes;
+import 'package:kernel/core_types.dart';
+
+import 'factory_specializer.dart';
+
+/// Replaces invocation of Set factory constructors with factories of
+/// Wasm-specific classes.
+///
+///     new LinkedHashSet<E>() => new DefaultSet<E>()
+class SetFactorySpecializer extends BaseSpecializer {
+  final Procedure _linkedHashSetDefaultFactory;
+  final Constructor _internalLinkedHashSetConstructor;
+
+  SetFactorySpecializer(CoreTypes coreTypes)
+      : _linkedHashSetDefaultFactory = coreTypes.index
+            .getProcedure('dart:collection', 'LinkedHashSet', ''),
+        _internalLinkedHashSetConstructor = coreTypes.index
+            .getConstructor('dart:_compact_hash', 'DefaultSet', '') {
+    transformers.addAll({_linkedHashSetDefaultFactory: transformLinkedHashSet});
+  }
+
+  TreeNode transformLinkedHashSet(StaticInvocation node) {
+    final args = node.arguments;
+    assert(args.positional.isEmpty);
+    if (args.named.isEmpty) {
+      return ConstructorInvocation(
+        _internalLinkedHashSetConstructor,
+        Arguments([], types: args.types),
+      );
+    }
+    return node;
+  }
+}
diff --git a/pkg/dart2wasm/lib/transformers.dart b/pkg/dart2wasm/lib/transformers.dart
@@ -9,7 +9,7 @@ import 'package:kernel/core_types.dart';
 import 'package:kernel/type_algebra.dart';
 import 'package:kernel/type_environment.dart';
 
-import 'list_factory_specializer.dart';
+import 'factory_specializer.dart';
 import 'util.dart';
 
 void transformLibraries(
@@ -63,7 +63,7 @@ class _WasmTransformer extends Transformer {
   final List<_AsyncStarFrame> _asyncStarFrames = [];
   bool _enclosingIsAsyncStar = false;
 
-  final ListFactorySpecializer _listFactorySpecializer;
+  final FactorySpecializer _factorySpecializer;
 
   final PushPopWasmArrayTransformer _pushPopWasmArrayTransformer;
 
@@ -119,7 +119,7 @@ class _WasmTransformer extends Transformer {
             .getTopLevelProcedure("dart:_internal", "loadLibrary"),
         _checkLibraryIsLoaded = coreTypes.index
             .getTopLevelProcedure("dart:_internal", "checkLibraryIsLoaded"),
-        _listFactorySpecializer = ListFactorySpecializer(coreTypes),
+        _factorySpecializer = FactorySpecializer(coreTypes),
         _pushPopWasmArrayTransformer = PushPopWasmArrayTransformer(coreTypes);
 
   @override
@@ -738,8 +738,14 @@ class _WasmTransformer extends Transformer {
       node.target = _trySetStackTrace;
     }
 
-    return _pushPopWasmArrayTransformer.transformStaticInvocation(
-        _listFactorySpecializer.transformStaticInvocation(node));
+    TreeNode transformed =
+        _pushPopWasmArrayTransformer.transformStaticInvocation(node);
+
+    if (transformed is StaticInvocation) {
+      transformed = _factorySpecializer.transformStaticInvocation(transformed);
+    }
+
+    return transformed;
   }
 
   @override
diff --git a/pkg/vm/lib/modular/specializer/map_factory_specializer.dart b/pkg/vm/lib/modular/specializer/map_factory_specializer.dart
@@ -16,20 +16,20 @@ class MapFactorySpecializer extends BaseSpecializer {
   final Constructor _internalLinkedHashMapConstructor;
 
   MapFactorySpecializer(CoreTypes coreTypes)
-    : _linkedHashMapDefaultFactory = assertNotNull(
-        coreTypes.index.getProcedure('dart:collection', 'LinkedHashMap', ''),
+    : _linkedHashMapDefaultFactory = coreTypes.index.getProcedure(
+        'dart:collection',
+        'LinkedHashMap',
+        '',
       ),
-      _internalLinkedHashMapConstructor = assertNotNull(
-        coreTypes.index.getConstructor('dart:_compact_hash', '_Map', ''),
+
+      _internalLinkedHashMapConstructor = coreTypes.index.getConstructor(
+        'dart:_compact_hash',
+        '_Map',
+        '',
       ) {
     transformers.addAll({_linkedHashMapDefaultFactory: transformLinkedHashMap});
   }
 
-  static T assertNotNull<T>(T t) {
-    assert(t != null);
-    return t;
-  }
-
   TreeNode transformLinkedHashMap(StaticInvocation node) {
     final args = node.arguments;
     if (args.named.isEmpty) {
diff --git a/pkg/vm/lib/modular/specializer/set_factory_specializer.dart b/pkg/vm/lib/modular/specializer/set_factory_specializer.dart
@@ -17,20 +17,20 @@ class SetFactorySpecializer extends BaseSpecializer {
   final Constructor _internalLinkedHashSetConstructor;
 
   SetFactorySpecializer(CoreTypes coreTypes)
-    : _linkedHashSetDefaultFactory = assertNotNull(
-        coreTypes.index.getProcedure('dart:collection', 'LinkedHashSet', ''),
+    : _linkedHashSetDefaultFactory = coreTypes.index.getProcedure(
+        'dart:collection',
+        'LinkedHashSet',
+        '',
       ),
-      _internalLinkedHashSetConstructor = assertNotNull(
-        coreTypes.index.getConstructor('dart:_compact_hash', '_Set', ''),
+
+      _internalLinkedHashSetConstructor = coreTypes.index.getConstructor(
+        'dart:_compact_hash',
+        '_Set',
+        '',
       ) {
     transformers.addAll({_linkedHashSetDefaultFactory: transformLinkedHashSet});
   }
 
-  static T assertNotNull<T>(T t) {
-    assert(t != null);
-    return t;
-  }
-
   TreeNode transformLinkedHashSet(StaticInvocation node) {
     final args = node.arguments;
     assert(args.positional.isEmpty);
diff --git a/tests/web/wasm/source_map_simple_optimized_test.dart b/tests/web/wasm/source_map_simple_optimized_test.dart
@@ -14,7 +14,6 @@ const List<(String?, int?, int?, String?)?> frameDetails = [
   ('errors_patch.dart', null, null, '_throwWithCurrentStackTrace'),
   ('source_map_simple_lib.dart', 16, 3, 'g'),
   ('source_map_simple_lib.dart', 12, 3, 'f'),
-  ('source_map_simple_lib.dart', 39, 5, 'testMain'),
 ];
 
 /*
