[dynamic modules] Fix dynamic interface validation of extension types

Instead of validating the erasure of an extension type,
validate that extension type declaration and type arguments
are specified as callable.

TEST=pkg/dynamic_modules/test/data/extension_type2

Fixes b/411433443

Change-Id: I063f0a622abd0d75594c4095573b29a7888f5afb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/423882
Reviewed-by: Sigmund Cherem <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Alexander Markov <[email protected]>

Author: alexmarkov

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -5666,6 +5666,43 @@ const MessageCode messageExtensionTypeRepresentationTypeBottom =
   problemMessage: r"""The representation type can't be a bottom type.""",
 );
 
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Template<Message Function(String name)>
+    templateExtensionTypeShouldBeListedAsCallableInDynamicInterface =
+    const Template<Message Function(String name)>(
+  "ExtensionTypeShouldBeListedAsCallableInDynamicInterface",
+  problemMessageTemplate:
+      r"""Cannot use extension type '#name' in a dynamic module.""",
+  correctionMessageTemplate:
+      r"""Try removing the reference to extension type '#name' or update the dynamic interface to list extension type '#name' as callable.""",
+  withArguments:
+      _withArgumentsExtensionTypeShouldBeListedAsCallableInDynamicInterface,
+);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Message Function(String name)>
+    codeExtensionTypeShouldBeListedAsCallableInDynamicInterface =
+    const Code<Message Function(String name)>(
+  "ExtensionTypeShouldBeListedAsCallableInDynamicInterface",
+);
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+Message _withArgumentsExtensionTypeShouldBeListedAsCallableInDynamicInterface(
+    String name) {
+  if (name.isEmpty) throw 'No name provided';
+  name = demangleMixinApplicationName(name);
+  return new Message(
+    codeExtensionTypeShouldBeListedAsCallableInDynamicInterface,
+    problemMessage:
+        """Cannot use extension type '${name}' in a dynamic module.""",
+    correctionMessage:
+        """Try removing the reference to extension type '${name}' or update the dynamic interface to list extension type '${name}' as callable.""",
+    arguments: {
+      'name': name,
+    },
+  );
+}
+
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Code<Null> codeExtensionTypeWith = messageExtensionTypeWith;
 

pkg/dynamic_modules/test/data/extension_type2/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_type2/main.dart

@@ -0,0 +1,14 @@
+// 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
+
+void main() async {
+  final result = (await helper.load('entry1.dart')) as int;
+  Expect.equals(1, result);
+  helper.done();
+}

pkg/dynamic_modules/test/data/extension_type2/modules/entry1.dart

@@ -0,0 +1,10 @@
+// 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() => method(value);
+
+int method(B b) => b.foo();

pkg/dynamic_modules/test/data/extension_type2/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.
+
+import 'shared_a.dart';
+
+B get value => B(A());
+
+extension type B(A _internal) {
+  int foo() => 1;
+}

pkg/dynamic_modules/test/data/extension_type2/shared/shared_a.dart

@@ -0,0 +1,5 @@
+// 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.
+
+class A {}

pkg/front_end/lib/src/kernel/dynamic_module_validator.dart

@@ -8,13 +8,16 @@ import 'package:kernel/core_types.dart' show CoreTypes;
 import 'package:kernel/library_index.dart' show LibraryIndex;
 import 'package:yaml/yaml.dart';
 import '../source/source_loader.dart' show SourceLoader;
+import '../api_prototype/lowering_predicates.dart'
+    show extractQualifiedNameFromExtensionMethodName;
 
 import '../codes/cfe_codes.dart'
     show
         messageDynamicCallsAreNotAllowedInDynamicModule,
         noLength,
         templateConstructorShouldBeListedAsCallableInDynamicInterface,
         templateMemberShouldBeListedAsCallableInDynamicInterface,
+        templateExtensionTypeShouldBeListedAsCallableInDynamicInterface,
         templateClassShouldBeListedAsCallableInDynamicInterface,
         templateClassShouldBeListedAsExtendableInDynamicInterface,
         templateMemberShouldBeListedAsCanBeOverriddenInDynamicInterface;
@@ -214,13 +217,19 @@ class DynamicInterfaceLanguageImplPragmas {
 
   bool isCallable(TreeNode node) => switch (node) {
         Member() => isPlatformLibrary(node.enclosingLibrary) &&
-            // Coverage-ignore(suite): Not run.
             (isAnnotatedWith(node, callablePragmaName) ||
                 (!node.name.isPrivate &&
                     node.enclosingClass != null &&
                     isAnnotatedWith(node.enclosingClass!, callablePragmaName))),
         Class() => isPlatformLibrary(node.enclosingLibrary) &&
             isAnnotatedWith(node, callablePragmaName),
+        ExtensionTypeDeclaration() =>
+          isPlatformLibrary(node.enclosingLibrary) &&
+              // Coverage-ignore(suite): Not run.
+              isAnnotatedWith(node, callablePragmaName),
+        // Coverage-ignore(suite): Not run.
+        Extension() => isPlatformLibrary(node.enclosingLibrary) &&
+            isAnnotatedWith(node, callablePragmaName),
         _ => // Coverage-ignore(suite): Not run.
           throw 'Unexpected node ${node.runtimeType} $node'
       };
@@ -230,7 +239,6 @@ class DynamicInterfaceLanguageImplPragmas {
       if (annotation case ConstantExpression(:var constant)) {
         if (constant case InstanceConstant(:var classNode, :var fieldValues)
             when classNode == coreTypes.pragmaClass) {
-          // Coverage-ignore-block(suite): Not run.
           if (fieldValues[coreTypes.pragmaName.fieldReference]
               case StringConstant(:var value) when value == pragmaName) {
             return true;
@@ -254,19 +262,69 @@ class _DynamicModuleValidator extends RecursiveVisitor {
 
   _DynamicModuleValidator(this.spec, this.languageImplPragmas,
       this.moduleLibraries, this.hierarchy, this.loader) {
-    _addLibraryExports(spec.callable);
-    _addLibraryExports(spec.extendable);
-    _addLibraryExports(spec.canBeOverridden);
+    _expandNodes(spec.callable);
+    _expandNodes(spec.extendable);
+    _expandNodes(spec.canBeOverridden);
   }
 
-  void _addLibraryExports(Set<TreeNode> nodes) {
-    Set<TreeNode> exports = {};
+  // Add nodes which do not have direct relation to its logical "parent" node.
+  void _expandNodes(Set<TreeNode> nodes) {
+    Set<TreeNode> extraNodes = {};
     for (TreeNode node in nodes) {
-      if (node is Library) {
-        exports.addAll(node.additionalExports.map((ref) => ref.node!));
-      }
+      _expandNode(node, extraNodes);
+    }
+    nodes.addAll(extraNodes);
+  }
+
+  // Add re-exports of Library and members of ExtensionTypeDeclaration and
+  // Extension. These nodes do not have direct relations to their "parents".
+  void _expandNode(TreeNode node, Set<TreeNode> extraNodes) {
+    switch (node) {
+      case Library():
+        for (Reference ref in node.additionalExports) {
+          TreeNode node = ref.node!;
+          extraNodes.add(node);
+          _expandNode(node, extraNodes);
+        }
+        for (ExtensionTypeDeclaration e in node.extensionTypeDeclarations) {
+          // Coverage-ignore-block(suite): Not run.
+          if (e.name[0] != '_') {
+            _expandNode(e, extraNodes);
+          }
+        }
+        for (Extension e in node.extensions) {
+          // Coverage-ignore-block(suite): Not run.
+          if (e.name[0] != '_') {
+            _expandNode(e, extraNodes);
+          }
+        }
+      case ExtensionTypeDeclaration():
+        for (ExtensionTypeMemberDescriptor md in node.memberDescriptors) {
+          TreeNode? member = md.memberReference?.node;
+          if (member != null) {
+            extraNodes.add(member);
+          }
+          TreeNode? tearOff = md.tearOffReference?.node;
+          if (tearOff != null) {
+            extraNodes.add(tearOff);
+          }
+        }
+      case Extension():
+        for (ExtensionMemberDescriptor md in node.memberDescriptors) {
+          TreeNode? member = md.memberReference?.node;
+          if (member != null) {
+            extraNodes.add(member);
+          }
+          TreeNode? tearOff = md
+              .tearOffReference
+              // Coverage-ignore(suite): Not run.
+              ?.node;
+          if (tearOff != null) {
+            // Coverage-ignore-block(suite): Not run.
+            extraNodes.add(tearOff);
+          }
+        }
     }
-    nodes.addAll(exports);
   }
 
   @override
@@ -479,9 +537,9 @@ class _DynamicModuleValidator extends RecursiveVisitor {
   }
 
   @override
-  // Coverage-ignore(suite): Not run.
   void visitExtensionType(ExtensionType node) {
-    node.extensionTypeErasure.accept(this);
+    _verifyCallable(node.extensionTypeDeclaration, _enclosingTreeNode!);
+    super.visitExtensionType(node);
   }
 
   @override
@@ -570,9 +628,15 @@ class _DynamicModuleValidator extends RecursiveVisitor {
               node.location!.file);
         case Member():
           final Class? cls = target.enclosingClass;
-          final String name = (cls != null)
-              ? '${cls.name}.${target.name.text}'
-              : target.name.text;
+          String name;
+          if (cls != null) {
+            name = '${cls.name}.${target.name.text}';
+          } else {
+            name = target.name.text;
+            if (target.isExtensionMember || target.isExtensionTypeMember) {
+              name = extractQualifiedNameFromExtensionMethodName(name)!;
+            }
+          }
           loader.addProblem(
               templateMemberShouldBeListedAsCallableInDynamicInterface
                   .withArguments(name),
@@ -586,6 +650,13 @@ class _DynamicModuleValidator extends RecursiveVisitor {
               node.fileOffset,
               noLength,
               node.location!.file);
+        case ExtensionTypeDeclaration():
+          loader.addProblem(
+              templateExtensionTypeShouldBeListedAsCallableInDynamicInterface
+                  .withArguments(target.name),
+              node.fileOffset,
+              noLength,
+              node.location!.file);
         // Coverage-ignore(suite): Not run.
         case _:
           throw 'Unexpected node ${node.runtimeType} $node';
@@ -659,6 +730,7 @@ class _DynamicModuleValidator extends RecursiveVisitor {
   Library _enclosingLibrary(TreeNode node) => switch (node) {
         Member() => node.enclosingLibrary,
         Class() => node.enclosingLibrary,
+        ExtensionTypeDeclaration() => node.enclosingLibrary,
         // Coverage-ignore(suite): Not run.
         Library() => node,
         _ => // Coverage-ignore(suite): Not run.
@@ -672,6 +744,8 @@ class _DynamicModuleValidator extends RecursiveVisitor {
           !node.name.isPrivate && _isSpecified(node.parent!, specified),
         Class() =>
           node.name[0] != '_' && _isSpecified(node.enclosingLibrary, specified),
+        ExtensionTypeDeclaration() =>
+          node.name[0] != '_' && _isSpecified(node.enclosingLibrary, specified),
         Library() => false,
         _ => // Coverage-ignore(suite): Not run.
           throw 'Unexpected node ${node.runtimeType} $node'

pkg/front_end/messages.status

@@ -334,6 +334,8 @@ ExtensionTypeImplementsDeferred/part_wrapped_script: Fail # Uses imports
 ExtensionTypeImplementsDeferred/script: Fail # Uses imports
 ExtensionTypePrimaryConstructorFunctionFormalParameterSyntax/analyzerCode: Fail
 ExtensionTypePrimaryConstructorWithInitializingFormal/analyzerCode: Fail
+ExtensionTypeShouldBeListedAsCallableInDynamicInterface/analyzerCode: Fail
+ExtensionTypeShouldBeListedAsCallableInDynamicInterface/example: Fail
 ExternalConstructorWithBody/part_wrapped_script1: Fail
 ExternalConstructorWithBody/script1: Fail
 ExternalConstructorWithFieldInitializers/example: Fail

pkg/front_end/messages.yaml

@@ -312,6 +312,10 @@ MemberShouldBeListedAsCallableInDynamicInterface:
   problemMessage: "Cannot invoke member '#name' from a dynamic module."
   correctionMessage: "Try removing the call or update the dynamic interface to list member '#name' as callable."
 
+ExtensionTypeShouldBeListedAsCallableInDynamicInterface:
+  problemMessage: "Cannot use extension type '#name' in a dynamic module."
+  correctionMessage: "Try removing the reference to extension type '#name' or update the dynamic interface to list extension type '#name' as callable."
+
 ClassShouldBeListedAsCallableInDynamicInterface:
   problemMessage: "Cannot use class '#name' in a dynamic module."
   correctionMessage: "Try removing the reference to class '#name' or update the dynamic interface to list class '#name' as callable."

pkg/front_end/test/coverage_suite_expected.dart

@@ -720,7 +720,7 @@ const Map<String, ({int hitCount, int missCount})> _expect = {
   ),
   // 100.0%.
   "package:front_end/src/kernel/dynamic_module_validator.dart": (
-    hitCount: 358,
+    hitCount: 416,
     missCount: 0,
   ),
   // 100.0%.

pkg/front_end/testcases/general/dynamic_modules/main.dart

@@ -125,10 +125,18 @@ void test() {
   // Allowed - target of redirecting factory is callable.
   print(C9());
 
+  // Not allowed.
+  print(ExtType1);
+  print(ExtType1(42));
+  print(42.isPositive);
+
   // Allowed - re-exported through main_lib2.dart
   print(Lib3Class());
   lib3Method();
   lib3Field = 42;
+  print(Lib3ExtType);
+  print(Lib3ExtType(42));
+  print(42.lib3IsPositive);
 }
 
 void main() {}