Truley compute direct subtypes of native classes.

lib/compiler/implementation/native_emitter.dart

 // Copyright (c) 2012, 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 NativeEmitter {
 
   Compiler compiler;
   StringBuffer buffer;
 
   // Classes that participate in dynamic dispatch. These are the
   // classes that contain used members.
   Set<ClassElement> classesWithDynamicDispatch;
 
   // Native classes found in the application.
   Set<ClassElement> nativeClasses;
 
+  // Caches the native subtypes of a native class.
+  Map<ClassElement, List<ClassElement>> subtypes;
+
   // Caches the direct native subtypes of a native class.
-  Map<ClassElement, List<ClassElement>> subtypes;
+  Map<ClassElement, List<ClassElement>> directSubtypes;
 
   // Caches the native methods that are overridden by a native class.
   // Note that the method that overrides does not have to be native:
   // it's the overridden method that must make sure it will dispatch
   // to its subclass if it sees an instance whose class is a subclass.
   Set<FunctionElement> overriddenMethods;
 
   NativeEmitter(this.compiler)
       : classesWithDynamicDispatch = new Set<ClassElement>(),
         nativeClasses = new Set<ClassElement>(),
         subtypes = new Map<ClassElement, List<ClassElement>>(),
+        directSubtypes = new Map<ClassElement, List<ClassElement>>(),
         overriddenMethods = new Set<FunctionElement>(),
         buffer = new StringBuffer();
 
   String get dynamicName() {
     Element element = compiler.findHelper(
         const SourceString('dynamicFunction'));
     return compiler.namer.isolateAccess(element);
   }
 
   String get dynamicSetMetadataName() {
@@ skipping 85 matching lines @@
     compiler.emitter.generateTypeTests(classElement, (Element other) {
       assert(requiresNativeIsCheck(other));
       buffer.add('${attachTo(compiler.namer.operatorIs(other))} = ');
       buffer.add('function() { return true; };\n');
     });
 
     if (hasUsedSelectors) classesWithDynamicDispatch.add(classElement);
   }
 
   List<ClassElement> getDirectSubclasses(ClassElement cls) {
-    List<ClassElement> result = subtypes[cls];
-    if (result === null) result = const<ClassElement>[];
-    return result;
+    List<ClassElement> result = directSubtypes[cls];
+    return result === null ? const<ClassElement>[] : result;
   }
 
   void potentiallyConvertDartClosuresToJs(StringBuffer code,
                                           FunctionElement member) {
     FunctionParameters parameters = member.computeParameters(compiler);
     Element converter =
         compiler.findHelper(const SourceString('convertDartClosureToJS'));
     String closureConverter = compiler.namer.isolateAccess(converter);
     parameters.forEachParameter((Element parameter) {
       Type type = parameter.computeType(compiler);
@@ skipping 203 matching lines @@
     String toStringName = compiler.namer.instanceMethodName(
         null, const SourceString('toString'), 0);
     objectProperties.add("$defPropName(Object.prototype, '$toStringName', ");
     objectProperties.add(
         'function() { return $toStringHelperName(this); });\n');
 
     // Finally, emit the code in the main buffer.
     targetBuffer.add('(function() {\n$objectProperties$buffer\n})();\n');
   }
 }