dart2js: Change typedef encoding.

sdk/lib/_internal/compiler/js_lib/js_mirrors.dart

 // Copyright (c) 2013, 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 dart._js_mirrors;
 
-import 'dart:_js_runtime_data' as encoding;
 import 'dart:_js_embedded_names' show
     ALL_CLASSES,
     LAZIES,
     LIBRARIES,
     STATICS,
-    TYPE_INFORMATION;
+    TYPE_INFORMATION,
+    TYPEDEF_PREDICATE_PROPERTY_NAME,
+    TYPEDEF_TYPE_PROPERTY_NAME;
 
 import 'dart:collection' show
     UnmodifiableListView,
     UnmodifiableMapView;
 
 import 'dart:mirrors';
 
 import 'dart:_foreign_helper' show
     JS,
     JS_CURRENT_ISOLATE,
@@ skipping 603 matching lines @@
     // Probably an intercepted class.
     // TODO(ahe): How to handle intercepted classes?
     throw new UnsupportedError('Cannot find class for: ${n(symbol)}');
   }
   var descriptor = JS('', '#["@"]', constructor);
   var fields;
   var fieldsMetadata;
   if (descriptor == null) {
     // This is a native class, or an intercepted class.
     // TODO(ahe): Preserve descriptor for such classes.
+  } else if (JS('bool', '# in #',
+                TYPEDEF_PREDICATE_PROPERTY_NAME, descriptor)) {
+    // Typedefs are represented as normal classes with two special properties:
+    //   TYPEDEF_PREDICATE_PROPERTY_NAME and TYPEDEF_TYPE_PROPERTY_NAME.
+    // For example:
+    //  MyTypedef: {
+    //     "^": "Object;",
+    //     $typedefType: 58,
+    //     $$isTypedef: true
+    //  }
+    //  The typedefType is the index into the metadata table.
+    int index = JS('int', '#[#]', descriptor, TYPEDEF_TYPE_PROPERTY_NAME);
+    mirror = new JsTypedefMirror(symbol, mangledName, getMetadata(index));
   } else {
     fields = JS('', '#[#]', descriptor,
         JS_GET_NAME('CLASS_DESCRIPTOR_PROPERTY'));
     if (fields is List) {
       fieldsMetadata = fields.getRange(1, fields.length).toList();
       fields = fields[0];
     }
     if (fields is! String) {
       // TODO(ahe): This is CSP mode.  Find a way to determine the
       // fields of this class.
       fields = '';
     }
   }
 
-  if (encoding.isTypedefDescriptor(fields)) {
-    int index = encoding.getTypeFromTypedef(fields);
-    mirror = new JsTypedefMirror(symbol, mangledName, getMetadata(index));
-  } else {
+  if (mirror == null) {
     var superclassName = fields.split(';')[0];
     var mixins = superclassName.split('+');
     if (mixins.length > 1 && mangledGlobalNames[mangledName] == null) {
       mirror = reflectMixinApplication(mixins, mangledName);
     } else {
       ClassMirror classMirror = new JsClassMirror(
           symbol, mangledName, constructor, fields, fieldsMetadata);
       List typeVariables =
           JS('JSExtendableArray|Null', '#.prototype["<>"]', constructor);
       if (typeVariables == null || typeVariables.length == 0) {
@@ skipping 2349 matching lines @@
   // have a part (following a '.') that starts with '_'.
   const int UNDERSCORE = 0x5f;
   if (name.isEmpty) return true;
   int index = -1;
   do {
     if (name.codeUnitAt(index + 1) == UNDERSCORE) return false;
     index = name.indexOf('.', index + 1);
   } while (index >= 0 && index + 1 < name.length);
   return true;
 }