[vm, dynamic_modules] Support extensions and extension types in dynamic interface annotator

TEST=pkg/vm/test/transformations/dynamic_interface_annotator_test.dart

Bug: b/404399018
Change-Id: I9b4baafc0c75b62f4fe15cb1191f0e31669a8538
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416340
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>

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

@@ -0,0 +1,16 @@
+# 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.
+
+callable:
+  - library: 'shared/shared.dart'
+    # TODO(sigmund): This should be included by default
+  - library: 'dart:core'
+    class: 'Object'
+  - library: 'dart:core'
+    class: 'int'
+  - library: 'dart:core'
+    class: 'String'
+  - library: 'dart:core'
+    class: 'pragma'
+    member: '_'

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

@@ -0,0 +1,16 @@
+// 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 '../../common/testing.dart' as helper;
+import 'package:expect/expect.dart';
+
+import 'shared/shared.dart'; // ignore: unused_import
+
+/// A dynamic module is allowed to extend a class in the dynamic interface and
+/// override its members.
+void main() async {
+  final result = (await helper.load('entry1.dart')) as String;
+  Expect.equals('abcdef42', result);
+  helper.done();
+}

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

@@ -0,0 +1,9 @@
+// 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 '../shared/shared.dart';
+
+@pragma('dyn-module:entry-point')
+Object? dynamicModuleEntrypoint() =>
+    'abc'.addSuffix('def') + MyExtensionType.foo(42).info.toString();

pkg/dynamic_modules/test/data/extension_type/shared/shared.dart

@@ -0,0 +1,11 @@
+// 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.
+
+extension type MyExtensionType.foo(int _info) {
+  int get info => _info;
+}
+
+extension MyExtension on String {
+  String addSuffix(String suffix) => this + suffix;
+}

pkg/vm/lib/transformations/dynamic_interface_annotator.dart

@@ -152,6 +152,16 @@ class _Annotator extends RecursiveVisitor {
         c.accept(this);
       }
     }
+    for (final ext in node.extensions) {
+      if (ext.name[0] != '_') {
+        ext.accept(this);
+      }
+    }
+    for (final extensionType in node.extensionTypeDeclarations) {
+      if (extensionType.name[0] != '_') {
+        extensionType.accept(this);
+      }
+    }
     for (final exportRef in node.additionalExports) {
       exportRef.node!.accept(this);
     }
@@ -207,6 +217,34 @@ class _Annotator extends RecursiveVisitor {
       node.addAnnotation(ConstantExpression(pragma));
     }
   }
+
+  @override
+  void visitExtension(Extension node) {
+    for (final md in node.memberDescriptors) {
+      final member = md.memberReference?.node;
+      if (member != null) {
+        annotateMember(member as Member);
+      }
+      final tearOff = md.tearOffReference?.node;
+      if (tearOff != null) {
+        annotateMember(tearOff as Member);
+      }
+    }
+  }
+
+  @override
+  void visitExtensionTypeDeclaration(ExtensionTypeDeclaration node) {
+    for (final md in node.memberDescriptors) {
+      final member = md.memberReference?.node;
+      if (member != null) {
+        annotateMember(member as Member);
+      }
+      final tearOff = md.tearOffReference?.node;
+      if (tearOff != null) {
+        annotateMember(tearOff as Member);
+      }
+    }
+  }
 }
 
 class _ImplicitExtendableAnnotator {

pkg/vm/testcases/transformations/dynamic_interface_annotator/dynamic_interface.yaml

@@ -9,12 +9,14 @@ callable:
     member: sfield9
   - library: 'lib3.dart'
     class: ['A', 'B']
+  - library: 'lib4.dart'
   - library: 'prefix/lib*'
 
 extendable:
   - library: 'lib1.dart'
     class: ['A', 'O', 'Q', 'S', 'T', 'V']
   - library: 'lib2.dart'
+  - library: 'lib4.dart'
 
 can-be-overridden:
   - library: 'lib1.dart'
@@ -22,3 +24,4 @@ can-be-overridden:
   - library: 'lib2.dart'
     class: 'D'
     member: 'build'
+  - library: 'lib4.dart'

pkg/vm/testcases/transformations/dynamic_interface_annotator/lib4.dart

@@ -0,0 +1,25 @@
+// 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.
+
+export 'lib5.dart';
+
+extension type E3(int _info) {
+  int get info => _info;
+}
+
+extension type _E4(int _info) {
+  int get info => _info;
+}
+
+extension E5 on String {
+  String addSuffix1(String suffix) => this + suffix;
+}
+
+extension _E6 on String {
+  String addSuffix2(String suffix) => this + suffix;
+}
+
+extension on String {
+  String addSuffix3(String suffix) => this + suffix;
+}

pkg/vm/testcases/transformations/dynamic_interface_annotator/lib4.dart.expect

@@ -0,0 +1,71 @@
+library;
+import self as self;
+import "dart:core" as core;
+import "lib5.dart" as lib5;
+additionalExports = (lib5::E1,
+  lib5::E2)
+
+export "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/lib5.dart";
+
+extension E5 on core::String {
+  method addSuffix1 = self::E5|addSuffix1;
+  method tearoff addSuffix1 = self::E5|get#addSuffix1;
+}
+extension _E6 on core::String {
+  method addSuffix2 = self::_E6|addSuffix2;
+  method tearoff addSuffix2 = self::_E6|get#addSuffix2;
+}
+extension /* unnamed */ _extension#2 on core::String {
+  method addSuffix3 = self::_extension#2|addSuffix3;
+  method tearoff addSuffix3 = self::_extension#2|get#addSuffix3;
+}
+extension type E3(core::int _info) {
+  abstract extension-type-member representation-field get _info() → core::int;
+  get info = self::E3|get#info;
+  constructor • = self::E3|constructor#;
+  constructor tearoff • = self::E3|constructor#_#new#tearOff;
+}
+extension type _E4(core::int _info) {
+  abstract extension-type-member representation-field get _info() → core::int;
+  get info = self::_E4|get#info;
+  constructor • = self::_E4|constructor#;
+  constructor tearoff • = self::_E4|constructor#_#new#tearOff;
+}
+@#C3
+static extension-type-member method E3|constructor#(core::int _info) → self::E3% /* erasure=core::int, declared=! */ {
+  lowered final self::E3% /* erasure=core::int, declared=! */ #this = _info;
+  return #this;
+}
+@#C3
+static extension-type-member method E3|constructor#_#new#tearOff(core::int _info) → self::E3% /* erasure=core::int, declared=! */
+  return self::E3|constructor#(_info);
+@#C3
+static extension-type-member method E3|get#info(lowered final self::E3% /* erasure=core::int, declared=! */ #this) → core::int
+  return #this as{Unchecked} core::int;
+static extension-type-member method _E4|constructor#(core::int _info) → self::_E4% /* erasure=core::int, declared=! */ {
+  lowered final self::_E4% /* erasure=core::int, declared=! */ #this = _info;
+  return #this;
+}
+static extension-type-member method _E4|constructor#_#new#tearOff(core::int _info) → self::_E4% /* erasure=core::int, declared=! */
+  return self::_E4|constructor#(_info);
+static extension-type-member method _E4|get#info(lowered final self::_E4% /* erasure=core::int, declared=! */ #this) → core::int
+  return #this as{Unchecked} core::int;
+@#C3
+static extension-member method E5|addSuffix1(lowered final core::String #this, core::String suffix) → core::String
+  return #this.{core::String::+}(suffix){(core::String) → core::String};
+@#C3
+static extension-member method E5|get#addSuffix1(lowered final core::String #this) → (core::String) → core::String
+  return (core::String suffix) → core::String => self::E5|addSuffix1(#this, suffix);
+static extension-member method _E6|addSuffix2(lowered final core::String #this, core::String suffix) → core::String
+  return #this.{core::String::+}(suffix){(core::String) → core::String};
+static extension-member method _E6|get#addSuffix2(lowered final core::String #this) → (core::String) → core::String
+  return (core::String suffix) → core::String => self::_E6|addSuffix2(#this, suffix);
+static extension-member method _extension#2|addSuffix3(lowered final core::String #this, core::String suffix) → core::String
+  return #this.{core::String::+}(suffix){(core::String) → core::String};
+static extension-member method _extension#2|get#addSuffix3(lowered final core::String #this) → (core::String) → core::String
+  return (core::String suffix) → core::String => self::_extension#2|addSuffix3(#this, suffix);
+constants  {
+  #C1 = "dyn-module:callable"
+  #C2 = null
+  #C3 = core::pragma {name:#C1, options:#C2}
+}

pkg/vm/testcases/transformations/dynamic_interface_annotator/lib5.dart

@@ -0,0 +1,11 @@
+// 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.
+
+extension type E1._(int _info) {
+  int get info => _info;
+}
+
+extension E2 on String {
+  int get lastChar => codeUnitAt(length - 1);
+}

pkg/vm/testcases/transformations/dynamic_interface_annotator/lib5.dart.expect

@@ -0,0 +1,32 @@
+library;
+import self as self;
+import "dart:core" as core;
+
+extension E2 on core::String {
+  get lastChar = self::E2|get#lastChar;
+}
+extension type E1(core::int _info) {
+  abstract extension-type-member representation-field get _info() → core::int;
+  get info = self::E1|get#info;
+  constructor _ = self::E1|constructor#_;
+  constructor tearoff _ = self::E1|constructor#_#_#tearOff;
+}
+@#C3
+static extension-type-member method E1|constructor#_(core::int _info) → self::E1% /* erasure=core::int, declared=! */ {
+  lowered final self::E1% /* erasure=core::int, declared=! */ #this = _info;
+  return #this;
+}
+@#C3
+static extension-type-member method E1|constructor#_#_#tearOff(core::int _info) → self::E1% /* erasure=core::int, declared=! */
+  return self::E1|constructor#_(_info);
+@#C3
+static extension-type-member method E1|get#info(lowered final self::E1% /* erasure=core::int, declared=! */ #this) → core::int
+  return #this as{Unchecked} core::int;
+@#C3
+static extension-member method E2|get#lastChar(lowered final core::String #this) → core::int
+  return #this.{core::String::codeUnitAt}(#this.{core::String::length}{core::int}.{core::num::-}(1){(core::num) → core::int}){(core::int) → core::int};
+constants  {
+  #C1 = "dyn-module:callable"
+  #C2 = null
+  #C3 = core::pragma {name:#C1, options:#C2}
+}

pkg/vm/testcases/transformations/dynamic_interface_annotator/main.dart

@@ -5,6 +5,7 @@
 import 'lib1.dart';
 import 'lib2.dart';
 import 'lib3.dart';
+import 'lib4.dart';
 import 'prefix/lib1.dart';
 import 'prefix/lib2.dart';
 

pkg/vm/testcases/transformations/dynamic_interface_annotator/main.dart.expect

@@ -4,6 +4,7 @@ import self as self;
 import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/lib1.dart";
 import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/lib2.dart";
 import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/lib3.dart";
+import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/lib4.dart";
 import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/prefix/lib1.dart";
 import "file:pkg/vm/testcases/transformations/dynamic_interface_annotator/prefix/lib2.dart";