Simplify runtime type support.

sdk/lib/_internal/compiler/implementation/js_backend/namer.dart

 // Copyright (c) 2011, 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.
 
 part of js_backend;
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
@@ skipping 190 matching lines @@
     usedGlobals[name] = 0;
     return name;
   }
 
   static const String LIBRARY_PREFIX = "lib";
 
   /**
    * Returns a preferred JS-id for the given top-level or static element.
    * The returned id is guaranteed to be a valid JS-id.
    */
-  String _computeGuess(Element element) {
+  String _computeGuess(Element element, bool allowUnsafeName) {
     assert(!element.isInstanceMember());
     LibraryElement lib = element.getLibrary();
     String name;
     if (element.isGenerativeConstructor()) {
       if (element.name == element.getEnclosingClass().name) {
         // Keep the class name for the class and not the factory.
         name = "${element.name.slowToString()}\$";
       } else {
         name = element.name.slowToString();
       }
     } else if (Elements.isStaticOrTopLevel(element)) {
       if (element.isMember()) {
         ClassElement enclosingClass = element.getEnclosingClass();
         name = "${enclosingClass.name.slowToString()}_"
                "${element.name.slowToString()}";
       } else {
         name = element.name.slowToString();
       }
     } else if (identical(element.kind, ElementKind.LIBRARY)) {
       name = LIBRARY_PREFIX;
     } else {
       name = element.name.slowToString();
     }
-    // Prefix the name with '$' if it is reserved.
-    return safeName(name);
+    // Prefix the name with '$' if it is reserved and we generate safe names.
+    return allowUnsafeName ? name : safeName(name);
   }
 
   String getBailoutName(Element element) {
     return '${getName(element)}\$bailout';
   }
 
   /**
    * Returns a preferred JS-id for the given element. The returned id is
    * guaranteed to be a valid JS-id. Globals and static fields are furthermore
    * guaranteed to be unique.
    *
    * For accessing statics consider calling
    * [isolateAccess]/[isolateBailoutAccess] or [isolatePropertyAccess] instead.
    */
-  String getName(Element element) {
+  String getName(Element element, {bool allowUnsafeName: false}) {
     if (element.isInstanceMember()) {
       if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY
           || element.kind == ElementKind.FUNCTION) {
         return instanceMethodName(element);
       } else if (element.kind == ElementKind.GETTER) {
         return getterName(element.getLibrary(), element.name);
       } else if (element.kind == ElementKind.SETTER) {
         return setterName(element.getLibrary(), element.name);
       } else if (element.kind == ElementKind.FIELD) {
         return instanceFieldName(element.getLibrary(), element.name);
       } else {
         compiler.internalError('getName for bad kind: ${element.kind}',
                                node: element.parseNode(compiler));
       }
     } else {
       // Use declaration element to ensure invariant on [globals].
       element = element.declaration;
-
       // Dealing with a top-level or static element.
       String cached = globals[element];
       if (cached != null) return cached;
 
-      String guess = _computeGuess(element);
+      String guess = _computeGuess(element, allowUnsafeName);
       ElementKind kind = element.kind;
       if (identical(kind, ElementKind.VARIABLE) ||
           identical(kind, ElementKind.PARAMETER)) {
         // The name is not guaranteed to be unique.
         return guess;
       }
       if (identical(kind, ElementKind.GENERATIVE_CONSTRUCTOR) ||
           identical(kind, ElementKind.FUNCTION) ||
           identical(kind, ElementKind.CLASS) ||
           identical(kind, ElementKind.FIELD) ||
@@ skipping 41 matching lines @@
   }
 
   String safeName(String name) {
     if (jsReserved.contains(name) || name.startsWith('\$')) {
       name = "\$$name";
       assert(!jsReserved.contains(name));
     }
     return name;
   }
 }