Support serialization of all resolved asts from dart:core

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

 // 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.
 
 library dart2js.js_backend.helpers;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Uris;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
 import '../core_types.dart' show CoreClasses;
 import '../elements/elements.dart'
     show
         AbstractFieldElement,
         ClassElement,
         ConstructorElement,
         Element,
         EnumClassElement,
         FunctionElement,
         LibraryElement,
-        MethodElement;
+        MethodElement,
+        PublicName;
 import '../library_loader.dart' show LoadedLibraries;
+import '../universe/call_structure.dart' show CallStructure;
+import '../universe/selector.dart' show Selector;
 
 import 'js_backend.dart';
 
 /// Helper classes and functions for the JavaScript backend.
 class BackendHelpers {
   static final Uri DART_JS_HELPER = new Uri(scheme: 'dart', path: '_js_helper');
   static final Uri DART_INTERCEPTORS =
       new Uri(scheme: 'dart', path: '_interceptors');
   static final Uri DART_FOREIGN_HELPER =
       new Uri(scheme: 'dart', path: '_foreign_helper');
@@ skipping 134 matching lines @@
 
   /// Holds the method "requiresPreamble" in _js_helper.
   FunctionElement requiresPreambleMarker;
 
   /// Holds the class for the [JsGetName] enum.
   EnumClassElement jsGetNameEnum;
 
   /// Holds the class for the [JsBuiltins] enum.
   EnumClassElement jsBuiltinEnum;
 
+  ClassElement _symbolImplementationClass;
+  ClassElement get symbolImplementationClass {
+    return _symbolImplementationClass ??= find(internalLibrary, 'Symbol');
+  }
+
+  final Selector symbolValidatedConstructorSelector =
+      new Selector.call(const PublicName('validated'), CallStructure.ONE_ARG);
+
+  ConstructorElement _symbolValidatedConstructor;
+
+  bool isSymbolValidatedConstructor(Element element) {
+    if (_symbolValidatedConstructor != null) {
+      return element == _symbolValidatedConstructor;
+    }
+    return false;
+  }
+
+  ConstructorElement get symbolValidatedConstructor {
+    return _symbolValidatedConstructor ??= _findConstructor(
+        symbolImplementationClass, symbolValidatedConstructorSelector.name);
+  }
+
   // TODO(johnniwinther): Make these private.
   // TODO(johnniwinther): Split into findHelperFunction and findHelperClass and
   // add a check that the element has the expected kind.
   Element findHelper(String name) => find(jsHelperLibrary, name);
   Element findAsyncHelper(String name) => find(asyncLibrary, name);
   Element findInterceptor(String name) => find(interceptorsLibrary, name);
   Element find(LibraryElement library, String name) {
     Element element = library.implementation.findLocal(name);
     assert(invariant(library, element != null,
         message: "Element '$name' not found in '${library.canonicalUri}'."));
     return element;
   }
 
+  ConstructorElement _findConstructor(ClassElement cls, String name) {
+    cls.ensureResolved(resolution);
+    ConstructorElement constructor = cls.lookupConstructor(name);
+    assert(invariant(cls, constructor != null,
+        message: "Constructor '$name' not found in '${cls}'."));
+    return constructor;
+  }
+
   void onLibraryCreated(LibraryElement library) {
     Uri uri = library.canonicalUri;
     if (uri == DART_JS_HELPER) {
       jsHelperLibrary = library;
     } else if (uri == Uris.dart_async) {
       asyncLibrary = library;
     } else if (uri == Uris.dart__internal) {
       internalLibrary = library;
     } else if (uri == DART_INTERCEPTORS) {
       interceptorsLibrary = library;
@@ skipping 473 matching lines @@
   MethodElement _objectNoSuchMethod;
 
   MethodElement get objectNoSuchMethod {
     if (_objectNoSuchMethod == null) {
       _objectNoSuchMethod =
           coreClasses.objectClass.lookupLocalMember(Identifiers.noSuchMethod_);
     }
     return _objectNoSuchMethod;
   }
 }