Some cleanup of the toplevel code generator:...

src/ast.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 169 matching lines @@
     kTestValue
   };
 
   Expression() : context_(kUninitialized) {}
 
   virtual Expression* AsExpression()  { return this; }
 
   virtual bool IsValidJSON() { return false; }
   virtual bool IsValidLeftHandSide() { return false; }
 
+  // Symbols that cannot be parsed as array indices are considered property
+  // names.  We do not treat symbols that can be array indexes as property
+  // names because [] for string objects is handled only by keyed ICs.
+  virtual bool IsPropertyName() { return false; }
+
   // Mark the expression as being compiled as an expression
   // statement. This is used to transform postfix increments to
   // (faster) prefix increments.
   virtual void MarkAsStatement() { /* do nothing */ }
 
   // Static type information for this expression.
   StaticType* type() { return &type_; }
 
   Context context() { return context_; }
   void set_context(Context context) { context_ = context; }
@@ skipping 500 matching lines @@
   // Type testing & conversion.
   virtual Literal* AsLiteral() { return this; }
 
   // Check if this literal is identical to the other literal.
   bool IsIdenticalTo(const Literal* other) const {
     return handle_.is_identical_to(other->handle_);
   }
 
   virtual bool IsValidJSON() { return true; }
 
+  virtual bool IsPropertyName() {
+    if (handle_->IsSymbol()) {
+      uint32_t ignored;
+      return !String::cast(*handle_)->AsArrayIndex(&ignored);
+    }
+    return false;
+  }
+
   // Identity testers.
   bool IsNull() const { return handle_.is_identical_to(Factory::null_value()); }
   bool IsTrue() const { return handle_.is_identical_to(Factory::true_value()); }
   bool IsFalse() const {
     return handle_.is_identical_to(Factory::false_value());
   }
 
   Handle<Object> handle() const { return handle_; }
 
  private:
@@ skipping 1076 matching lines @@
 #undef DEF_VISIT
 
  private:
   bool stack_overflow_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_