support @JS annotation from SDK

Attempt at fixing https://github.com/dart-lang/sdk/issues/39740 to allow the flutter web engine to use @JS
interop to avoid the overhead of the SDK available js interop.

Bug: 39740
Change-Id: I7ba9c8981e639cd267bee3086ba900b89bfc0d6f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150501
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Harry Terkelsen <het@google.com>

pkg/_js_interop_checks/lib/src/js_interop.dart

@@ -4,18 +4,21 @@
 
 import 'package:kernel/kernel.dart';
 
-/// Returns true iff the class has an `@JS(...)` annotation from `package:js`.
+/// Returns true iff the class has an `@JS(...)` annotation from `package:js`
+/// or from the internal `dart:_js_annotations`.
 bool hasJSInteropAnnotation(Class c) =>
     c.annotations.any(_isPublicJSAnnotation);
 
 final _packageJs = Uri.parse('package:js/js.dart');
+final _internalJs = Uri.parse('dart:_js_annotations');
 
 /// Returns [true] if [e] is the `JS` annotation from `package:js`.
 bool _isPublicJSAnnotation(Expression value) {
   var c = _annotationClass(value);
   return c != null &&
       c.name == 'JS' &&
-      c.enclosingLibrary.importUri == _packageJs;
+      (c.enclosingLibrary.importUri == _packageJs ||
+          c.enclosingLibrary.importUri == _internalJs);
 }
 
 /// Returns the class of the instance referred to by metadata annotation [node].

pkg/compiler/lib/src/common/names.dart

@@ -256,6 +256,10 @@ class Uris {
   /// The URI for 'package:js'.
   static final Uri package_js = new Uri(scheme: 'package', path: 'js/js.dart');
 
+  /// The URI for 'dart:_js_annotations'.
+  static final Uri dart__js_annotations =
+      Uri(scheme: 'dart', path: '_js_annotations');
+
   /// The URI for 'package:meta/dart2js.dart'.
   static final Uri package_meta_dart2js =
       new Uri(scheme: 'package', path: 'meta/dart2js.dart');

pkg/compiler/lib/src/common_elements.dart

@@ -111,6 +111,9 @@ abstract class CommonElements {
   /// The package:js library.
   LibraryEntity get packageJsLibrary;
 
+  /// The dart:_js_annotations library.
+  LibraryEntity get dartJsAnnotationsLibrary;
+
   /// The `NativeTypedData` class from dart:typed_data.
   ClassEntity get typedDataClass;
 
@@ -571,13 +574,35 @@ abstract class CommonElements {
       ClassEntity cls, NativeBasicData nativeBasicData);
 
   // From package:js
-  FunctionEntity get jsAllowInterop;
+  FunctionEntity get jsAllowInterop1;
+
+  // From dart:_js_annotations;
+  FunctionEntity get jsAllowInterop2;
+
+  /// Returns `true` if [function] is `allowInterop`.
+  ///
+  /// This function can come from either `package:js` or `dart:_js_annotations`.
+  bool isJsAllowInterop(FunctionEntity function);
 }
 
 abstract class KCommonElements implements CommonElements {
   // From package:js
-  ClassEntity get jsAnnotationClass;
-  ClassEntity get jsAnonymousClass;
+  ClassEntity get jsAnnotationClass1;
+  ClassEntity get jsAnonymousClass1;
+
+  // From dart:_js_annotations
+  ClassEntity get jsAnnotationClass2;
+  ClassEntity get jsAnonymousClass2;
+
+  /// Returns `true` if [cls] is a @JS() annotation.
+  ///
+  /// The class can come from either `package:js` or `dart:_js_annotations`.
+  bool isJsAnnotationClass(ClassEntity cls);
+
+  /// Returns `true` if [cls] is an @anonymous annotation.
+  ///
+  /// The class can come from either `package:js` or `dart:_js_annotations`.
+  bool isJsAnonymousClass(ClassEntity cls);
 
   ClassEntity get pragmaClass;
   FieldEntity get pragmaClassNameField;
@@ -824,6 +849,11 @@ class CommonElementsImpl
   LibraryEntity get packageJsLibrary =>
       _packageJsLibrary ??= _env.lookupLibrary(Uris.package_js);
 
+  LibraryEntity _dartJsAnnotationsLibrary;
+  @override
+  LibraryEntity get dartJsAnnotationsLibrary => _dartJsAnnotationsLibrary ??=
+      _env.lookupLibrary(Uris.dart__js_annotations);
+
   ClassEntity _typedDataClass;
   @override
   ClassEntity get typedDataClass =>
@@ -1481,22 +1511,57 @@ class CommonElementsImpl
       _jsConstClass ??= _findClass(foreignLibrary, 'JS_CONST');
 
   // From dart:js
-  FunctionEntity _jsAllowInterop;
+  FunctionEntity _jsAllowInterop1;
   @override
-  FunctionEntity get jsAllowInterop => _jsAllowInterop ??=
+  FunctionEntity get jsAllowInterop1 => _jsAllowInterop1 ??=
       _findLibraryMember(dartJsLibrary, 'allowInterop', required: false);
 
-  // From package:js
-  ClassEntity _jsAnnotationClass;
+  // From dart:_js_annotations
+  FunctionEntity _jsAllowInterop2;
   @override
-  ClassEntity get jsAnnotationClass => _jsAnnotationClass ??=
+  FunctionEntity get jsAllowInterop2 => _jsAllowInterop2 ??= _findLibraryMember(
+      dartJsAnnotationsLibrary, 'allowInterop',
+      required: false);
+
+  @override
+  bool isJsAllowInterop(FunctionEntity function) {
+    return function == jsAllowInterop1 || function == jsAllowInterop2;
+  }
+
+  // From package:js
+  ClassEntity _jsAnnotationClass1;
+  @override
+  ClassEntity get jsAnnotationClass1 => _jsAnnotationClass1 ??=
       _findClass(packageJsLibrary, 'JS', required: false);
 
-  ClassEntity _jsAnonymousClass;
+  // From dart:_js_annotations
+  ClassEntity _jsAnnotationClass2;
   @override
-  ClassEntity get jsAnonymousClass => _jsAnonymousClass ??=
+  ClassEntity get jsAnnotationClass2 => _jsAnnotationClass2 ??=
+      _findClass(dartJsAnnotationsLibrary, 'JS', required: false);
+
+  @override
+  bool isJsAnnotationClass(ClassEntity cls) {
+    return cls == jsAnnotationClass1 || cls == jsAnnotationClass2;
+  }
+
+  // From dart:js
+  ClassEntity _jsAnonymousClass1;
+  @override
+  ClassEntity get jsAnonymousClass1 => _jsAnonymousClass1 ??=
       _findClass(packageJsLibrary, '_Anonymous', required: false);
 
+  // From dart:_js_annotations
+  ClassEntity _jsAnonymousClass2;
+  @override
+  ClassEntity get jsAnonymousClass2 => _jsAnonymousClass2 ??=
+      _findClass(dartJsAnnotationsLibrary, '_Anonymous', required: false);
+
+  @override
+  bool isJsAnonymousClass(ClassEntity cls) {
+    return cls == jsAnonymousClass1 || cls == jsAnonymousClass2;
+  }
+
   @override
   FunctionEntity findHelperFunction(String name) => _findHelperFunction(name);
 

pkg/compiler/lib/src/ir/annotations.dart

@@ -295,7 +295,9 @@ String _getReturnsAnnotation(ir.Constant constant) {
 String _getJsInteropName(ir.Constant constant) {
   if (constant is ir.InstanceConstant &&
       constant.classNode.name == 'JS' &&
-      constant.classNode.enclosingLibrary.importUri == Uris.package_js) {
+      (constant.classNode.enclosingLibrary.importUri == Uris.package_js ||
+          constant.classNode.enclosingLibrary.importUri ==
+              Uris.dart__js_annotations)) {
     assert(constant.fieldValues.length == 1);
     ir.Constant fieldValue = constant.fieldValues.values.single;
     if (fieldValue is ir.NullConstant) {
@@ -310,7 +312,9 @@ String _getJsInteropName(ir.Constant constant) {
 bool _isAnonymousJsInterop(ir.Constant constant) {
   return constant is ir.InstanceConstant &&
       constant.classNode.name == '_Anonymous' &&
-      constant.classNode.enclosingLibrary.importUri == Uris.package_js;
+      (constant.classNode.enclosingLibrary.importUri == Uris.package_js ||
+          constant.classNode.enclosingLibrary.importUri ==
+              Uris.dart__js_annotations);
 }
 
 class PragmaAnnotationData {

pkg/compiler/lib/src/js_backend/backend_impact.dart

@@ -562,7 +562,8 @@ class BackendImpacts {
 
   BackendImpact get allowInterop => _allowInterop ??= BackendImpact(
           staticUses: [
-            _commonElements.jsAllowInterop,
+            _commonElements.jsAllowInterop1,
+            _commonElements.jsAllowInterop2,
           ],
           features: EnumSet<BackendFeature>.fromValues([
             BackendFeature.needToInitializeIsolateAffinityTag,

pkg/compiler/lib/src/kernel/native_basic_data.dart

@@ -33,8 +33,10 @@ class KernelAnnotationProcessor implements AnnotationProcessor {
     String annotationName;
     for (ConstantValue value in metadata) {
       String name = readAnnotationName(commonElements.dartTypes, spannable,
-          value, commonElements.jsAnnotationClass,
-          defaultValue: '');
+              value, commonElements.jsAnnotationClass1, defaultValue: '') ??
+          readAnnotationName(commonElements.dartTypes, spannable, value,
+              commonElements.jsAnnotationClass2,
+              defaultValue: '');
       if (annotationName == null) {
         annotationName = name;
       } else if (name != null) {

pkg/compiler/lib/src/ssa/codegen.dart

@@ -2084,7 +2084,8 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
 
     List<js.Expression> arguments = visitArguments(node.inputs, start: 0);
 
-    if (element == _commonElements.jsAllowInterop) {
+    if (element == _commonElements.jsAllowInterop1 ||
+        element == _commonElements.jsAllowInterop2) {
       _nativeData.registerAllowInterop();
     }
 

pkg/compiler/test/jsinterop/internal_annotations_test.dart

@@ -0,0 +1,218 @@
+// Copyright (c) 2016, 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.
+
+// @dart = 2.7
+
+library jsinterop.internal_annotations_test;
+
+import 'package:expect/expect.dart';
+import 'package:async_helper/async_helper.dart';
+import 'package:compiler/src/common_elements.dart';
+import 'package:compiler/src/compiler.dart';
+import 'package:compiler/src/elements/entities.dart' show ClassEntity;
+import 'package:compiler/src/elements/names.dart';
+import 'package:compiler/src/universe/class_hierarchy.dart';
+import 'package:compiler/src/universe/selector.dart';
+import 'package:compiler/src/world.dart';
+import '../helpers/element_lookup.dart';
+import '../helpers/memory_compiler.dart';
+
+void main() {
+  asyncTest(() async {
+    await testClasses('package:js/js.dart', 'dart:_js_annotations');
+    await testClasses('package:js/js.dart', 'package:js/js.dart');
+    await testClasses('dart:_js_annotations', 'dart:_js_annotations');
+  });
+}
+
+testClasses(String import1, String import2) async {
+  test(String mainSource,
+      {List<String> directlyInstantiated: const <String>[],
+      List<String> abstractlyInstantiated: const <String>[],
+      List<String> indirectlyInstantiated: const <String>[]}) async {
+    String mainFile = 'sdk/tests/dart2js_2/native/main.dart';
+    Uri entryPoint = Uri.parse('memory:$mainFile');
+    CompilationResult result =
+        await runCompiler(entryPoint: entryPoint, memorySourceFiles: {
+      mainFile: """
+import '$import1' as js1;
+import '$import2' as js2;
+
+@js1.JS()
+class A {
+  external get foo;
+
+  external A(var foo);
+}
+
+@js2.JS('BClass')
+class B {
+  external get foo;
+
+  external B(var foo);
+}
+
+@js1.JS()
+@js1.anonymous
+class C {
+  external get foo;
+
+  external factory C({foo});
+}
+
+@js2.JS()
+@js2.anonymous
+class D {
+  external get foo;
+
+  external factory D({foo});
+}
+
+class E {
+  final foo;
+
+  E(this.foo);
+}
+
+class F {
+  final foo;
+
+  F(this.foo);
+}
+
+newA() => new A(0);
+newB() => new B(1);
+newC() => new C(foo: 2);
+newD() => new D(foo: 3);
+newE() => new E(4);
+newF() => new F(5);
+
+$mainSource
+"""
+    });
+    Compiler compiler = result.compiler;
+    Map<String, ClassEntity> classEnvironment = <String, ClassEntity>{};
+
+    ClassEntity registerClass(ClassEntity cls) {
+      classEnvironment[cls.name] = cls;
+      return cls;
+    }
+
+    JClosedWorld world = compiler.backendClosedWorldForTesting;
+    ElementEnvironment elementEnvironment = world.elementEnvironment;
+    ClassEntity Object_ = registerClass(world.commonElements.objectClass);
+    ClassEntity Interceptor =
+        registerClass(world.commonElements.jsInterceptorClass);
+    ClassEntity JavaScriptObject =
+        registerClass(world.commonElements.jsJavaScriptObjectClass);
+    ClassEntity A = registerClass(findClass(world, 'A'));
+    ClassEntity B = registerClass(findClass(world, 'B'));
+    ClassEntity C = registerClass(findClass(world, 'C'));
+    ClassEntity D = registerClass(findClass(world, 'D'));
+    ClassEntity E = registerClass(findClass(world, 'E'));
+    ClassEntity F = registerClass(findClass(world, 'F'));
+
+    Selector nonExisting = new Selector.getter(const PublicName('nonExisting'));
+
+    Expect.equals(elementEnvironment.getSuperClass(Interceptor), Object_);
+    Expect.equals(
+        elementEnvironment.getSuperClass(JavaScriptObject), Interceptor);
+
+    Expect.equals(elementEnvironment.getSuperClass(A), JavaScriptObject);
+    Expect.equals(elementEnvironment.getSuperClass(B), JavaScriptObject);
+    Expect.equals(elementEnvironment.getSuperClass(C), JavaScriptObject);
+    Expect.equals(elementEnvironment.getSuperClass(D), JavaScriptObject);
+    Expect.equals(elementEnvironment.getSuperClass(E), Object_);
+    Expect.equals(elementEnvironment.getSuperClass(F), Object_);
+
+    Expect.isFalse(world.nativeData.isJsInteropClass(Object_));
+    Expect.isTrue(world.nativeData.isJsInteropClass(A));
+    Expect.isTrue(world.nativeData.isJsInteropClass(B));
+    Expect.isTrue(world.nativeData.isJsInteropClass(C));
+    Expect.isTrue(world.nativeData.isJsInteropClass(D));
+    Expect.isFalse(world.nativeData.isJsInteropClass(E));
+    Expect.isFalse(world.nativeData.isJsInteropClass(F));
+
+    Expect.isFalse(world.nativeData.isAnonymousJsInteropClass(Object_));
+    Expect.isFalse(world.nativeData.isAnonymousJsInteropClass(A));
+    Expect.isFalse(world.nativeData.isAnonymousJsInteropClass(B));
+    Expect.isTrue(world.nativeData.isAnonymousJsInteropClass(C));
+    Expect.isTrue(world.nativeData.isAnonymousJsInteropClass(D));
+    Expect.isFalse(world.nativeData.isAnonymousJsInteropClass(E));
+    Expect.isFalse(world.nativeData.isAnonymousJsInteropClass(F));
+
+    Expect.equals('', world.nativeData.getJsInteropClassName(A));
+    Expect.equals('BClass', world.nativeData.getJsInteropClassName(B));
+    Expect.equals('', world.nativeData.getJsInteropClassName(C));
+    Expect.equals('', world.nativeData.getJsInteropClassName(D));
+
+    for (String name in classEnvironment.keys) {
+      ClassEntity cls = classEnvironment[name];
+      bool isInstantiated = false;
+      if (directlyInstantiated.contains(name)) {
+        isInstantiated = true;
+        Expect.isTrue(
+            world.classHierarchy.isDirectlyInstantiated(cls),
+            "Expected $name to be directly instantiated in `${mainSource}`:"
+            "\n${world.classHierarchy.dump(cls)}");
+      }
+      if (abstractlyInstantiated.contains(name)) {
+        isInstantiated = true;
+        Expect.isTrue(
+            world.classHierarchy.isAbstractlyInstantiated(cls),
+            "Expected $name to be abstractly instantiated in `${mainSource}`:"
+            "\n${world.classHierarchy.dump(cls)}");
+        Expect.isTrue(
+            world.needsNoSuchMethod(cls, nonExisting, ClassQuery.EXACT),
+            "Expected $name to need noSuchMethod for $nonExisting.");
+        Expect.isTrue(
+            world.needsNoSuchMethod(cls, nonExisting, ClassQuery.SUBCLASS),
+            "Expected $name to need noSuchMethod for $nonExisting.");
+        Expect.isTrue(
+            world.needsNoSuchMethod(cls, nonExisting, ClassQuery.SUBTYPE),
+            "Expected $name to need noSuchMethod for $nonExisting.");
+      }
+      if (indirectlyInstantiated.contains(name)) {
+        isInstantiated = true;
+        Expect.isTrue(
+            world.classHierarchy.isIndirectlyInstantiated(cls),
+            "Expected $name to be indirectly instantiated in `${mainSource}`:"
+            "\n${world.classHierarchy.dump(cls)}");
+      }
+      if (!isInstantiated && (name != 'Object' && name != 'Interceptor')) {
+        Expect.isFalse(
+            world.classHierarchy.isInstantiated(cls),
+            "Expected $name to be uninstantiated in `${mainSource}`:"
+            "\n${world.classHierarchy.dump(cls)}");
+      }
+    }
+  }
+
+  await test('main() {}');
+
+  await test('main() => newA();',
+      abstractlyInstantiated: ['A', 'B', 'C', 'D'],
+      indirectlyInstantiated: ['Object', 'Interceptor', 'JavaScriptObject']);
+
+  await test('main() => newB();',
+      abstractlyInstantiated: ['A', 'B', 'C', 'D'],
+      indirectlyInstantiated: ['Object', 'Interceptor', 'JavaScriptObject']);
+
+  await test('main() => newC();',
+      abstractlyInstantiated: ['A', 'B', 'C', 'D'],
+      indirectlyInstantiated: ['Object', 'Interceptor', 'JavaScriptObject']);
+
+  await test('main() => newD();',
+      abstractlyInstantiated: ['A', 'B', 'C', 'D'],
+      indirectlyInstantiated: ['Object', 'Interceptor', 'JavaScriptObject']);
+
+  await test('main() => newE();', directlyInstantiated: ['E']);
+
+  await test('main() => newF();', directlyInstantiated: ['F']);
+
+  await test('main() => [newD(), newE()];',
+      directlyInstantiated: ['E'],
+      abstractlyInstantiated: ['A', 'B', 'C', 'D'],
+      indirectlyInstantiated: ['Object', 'Interceptor', 'JavaScriptObject']);
+}

pkg/dev_compiler/lib/src/kernel/js_interop.dart

@@ -23,8 +23,12 @@ bool _isLibrary(Library library, List<String> candidates) {
 
 /// Returns true if [library] represents any library from `package:js` or is the
 /// internal `dart:_js_helper` library.
-bool _isJSLibrary(Library library) => _isLibrary(
-    library, ['package:js', 'dart:_js_helper', 'dart:_foreign_helper']);
+bool _isJSLibrary(Library library) => _isLibrary(library, [
+      'package:js',
+      'dart:_js_helper',
+      'dart:_foreign_helper',
+      'dart:_js_annotations'
+    ]);
 
 /// Whether [node] is a direct call to `allowInterop`.
 bool isAllowInterop(Expression node) {

sdk/lib/_internal/sdk_library_metadata/lib/libraries.dart

@@ -190,6 +190,8 @@ const Map<String, LibraryInfo> libraries = const {
       platforms: DART2JS_PLATFORM),
   "_metadata": const LibraryInfo("html/html_common/metadata.dart",
       categories: "", documented: false, platforms: DART2JS_PLATFORM),
+  "_js_annotations": const LibraryInfo("js/_js_annotations.dart",
+      categories: "", documented: false, platforms: DART2JS_PLATFORM),
 };
 
 /**

sdk/lib/js/_js_annotations.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2015, 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.
+
+// An implementation of the JS interop classes which are usable from the
+// Dart SDK. These types need to stay in-sync with
+// https://github.com/dart-lang/sdk/blob/master/pkg/js/lib/js.dart
+library _js_annotations;
+
+class JS {
+  final String name;
+  const JS([this.name]);
+}
+
+class _Anonymous {
+  const _Anonymous();
+}
+
+const _Anonymous anonymous = const _Anonymous();

sdk/lib/libraries.json

@@ -211,6 +211,9 @@
         "uri": "js/_js.dart",
         "patches": "js/_js_client.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "js_util": {
         "uri": "js_util/js_util.dart"
       },
@@ -321,6 +324,9 @@
         "uri": "js/_js.dart",
         "patches": "js/_js_server.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "js_util": {
         "uri": "js_util/js_util.dart"
       },
@@ -397,6 +403,9 @@
       "_isolate_helper": {
         "uri": "_internal/js_dev_runtime/private/isolate_helper.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "_js_helper": {
         "uri": "_internal/js_dev_runtime/private/js_helper.dart"
       },

sdk/lib/libraries.yaml

@@ -208,6 +208,9 @@ dart2js:
       uri: "js/_js.dart"
       patches: "js/_js_client.dart"
 
+    _js_annotations:
+      uri: "js/_js_annotations.dart"
+
     js_util:
       uri: "js_util/js_util.dart"
 
@@ -316,6 +319,9 @@ dart2js_server:
       uri: "js/_js.dart"
       patches: "js/_js_server.dart"
 
+    _js_annotations:
+      uri: "js/_js_annotations.dart"
+
     js_util:
       uri: "js_util/js_util.dart"
 
@@ -390,6 +396,9 @@ dartdevc:
       _isolate_helper:
         uri: "_internal/js_dev_runtime/private/isolate_helper.dart"
 
+      _js_annotations:
+        uri: "js/_js_annotations.dart"
+
       _js_helper:
         uri: "_internal/js_dev_runtime/private/js_helper.dart"
 

sdk_nnbd/lib/_internal/sdk_library_metadata/lib/libraries.dart

@@ -190,6 +190,8 @@ const Map<String, LibraryInfo> libraries = const {
       platforms: DART2JS_PLATFORM),
   "_metadata": const LibraryInfo("html/html_common/metadata.dart",
       categories: "", documented: false, platforms: DART2JS_PLATFORM),
+  "_js_annotations": const LibraryInfo("js/_js_annotations.dart",
+      categories: "", documented: false, platforms: DART2JS_PLATFORM),
 };
 
 /**

sdk_nnbd/lib/js/_js_annotations.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2015, 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.
+
+// An implementation of the JS interop classes which are usable from the
+// Dart SDK. These types need to stay in-sync with
+// https://github.com/dart-lang/sdk/blob/master/pkg/js/lib/js.dart
+library _js_annotations;
+
+class JS {
+  final String name;
+  const JS([this.name]);
+}
+
+class _Anonymous {
+  const _Anonymous();
+}
+
+const _Anonymous anonymous = const _Anonymous();

sdk_nnbd/lib/libraries.json

@@ -211,6 +211,9 @@
         "uri": "js/_js.dart",
         "patches": "js/_js_client.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "js_util": {
         "uri": "js_util/js_util.dart"
       },
@@ -321,6 +324,9 @@
         "uri": "js/_js.dart",
         "patches": "js/_js_server.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "js_util": {
         "uri": "js_util/js_util.dart"
       },
@@ -397,6 +403,9 @@
       "_isolate_helper": {
         "uri": "_internal/js_dev_runtime/private/isolate_helper.dart"
       },
+      "_js_annotations": {
+        "uri": "js/_js_annotations.dart"
+      },
       "_js_helper": {
         "uri": "_internal/js_dev_runtime/private/js_helper.dart"
       },

sdk_nnbd/lib/libraries.yaml

@@ -208,6 +208,9 @@ dart2js:
       uri: "js/_js.dart"
       patches: "js/_js_client.dart"
 
+    _js_annotations:
+      uri: "js/_js_annotations.dart"
+
     js_util:
       uri: "js_util/js_util.dart"
 
@@ -316,6 +319,9 @@ dart2js_server:
       uri: "js/_js.dart"
       patches: "js/_js_server.dart"
 
+    _js_annotations:
+      uri: "js/_js_annotations.dart"
+
     js_util:
       uri: "js_util/js_util.dart"
 
@@ -390,6 +396,9 @@ dartdevc:
       _isolate_helper:
         uri: "_internal/js_dev_runtime/private/isolate_helper.dart"
 
+      _js_annotations:
+        uri: "js/_js_annotations.dart"
+
       _js_helper:
         uri: "_internal/js_dev_runtime/private/js_helper.dart"