Convert all symbols accessor to return read only handles so that it is not necessary to create a ne…

vm/ast.cc

 // 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.
 
 #include "vm/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/resolver.h"
@@ skipping 395 matching lines @@
   return new StaticSetterNode(token_pos(), NULL, cls(), field_name(), rhs);
 }
 
 
 AstNode* StaticCallNode::MakeAssignmentNode(AstNode* rhs) {
   // Return this node if it represents a 'throw NoSuchMethodError' indicating
   // that a getter was not found, otherwise return null.
   const Class& cls = Class::Handle(function().Owner());
   const String& cls_name = String::Handle(cls.Name());
   const String& func_name = String::Handle(function().name());
-  const String& error_cls_name = String::Handle(Symbols::NoSuchMethodError());
-  const String& error_func_name = String::Handle(Symbols::ThrowNew());
-  if (cls_name.Equals(error_cls_name) &&
-      func_name.StartsWith(error_func_name)) {
+  if (cls_name.Equals(Symbols::NoSuchMethodError()) &&
+      func_name.StartsWith(Symbols::ThrowNew())) {
     return this;
   }
   return NULL;
 }
 
 
 const Instance* StaticGetterNode::EvalConstExpr() const {
   const String& getter_name =
       String::Handle(Field::GetterName(this->field_name()));
   const Function& getter_func =
       Function::Handle(this->cls().LookupStaticFunction(getter_name));
   if (getter_func.IsNull() || !getter_func.is_const()) {
     return NULL;
   }
   const Object& result = Object::Handle(
       DartEntry::InvokeStatic(getter_func, Object::empty_array()));
   if (result.IsError() || result.IsNull()) {
     // TODO(turnidge): We could get better error messages by returning
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   return &Instance::ZoneHandle(Instance::Cast(result).raw());
 }
 
 }  // namespace dart