Add support for API accessors that prohibit overwriting by accessors...

src/runtime.cc

 // 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 318 matching lines @@
   RUNTIME_ASSERT(offset > 0);
   if (type ==  FUNCTION_TEMPLATE_INFO_TYPE) {
     RUNTIME_ASSERT(offset < FunctionTemplateInfo::kSize);
   } else {
     RUNTIME_ASSERT(offset < ObjectTemplateInfo::kSize);
   }
   return *HeapObject::RawField(templ, offset);
 }
 
 
+static Object* Runtime_DisableAccessChecks(Arguments args) {
+  ASSERT(args.length() == 1);
+  CONVERT_CHECKED(HeapObject, object, args[0]);
+  bool needs_access_checks = object->map()->is_access_check_needed();
+  object->map()->set_is_access_check_needed(false);
+  return needs_access_checks ? Heap::true_value() : Heap::false_value();
+}
+
+
+static Object* Runtime_EnableAccessChecks(Arguments args) {
+  ASSERT(args.length() == 1);
+  CONVERT_CHECKED(HeapObject, object, args[0]);
+  object->map()->set_is_access_check_needed(true);
+  return Heap::undefined_value();
+}
+
+
 static Object* ThrowRedeclarationError(const char* type, Handle<String> name) {
   HandleScope scope;
   Handle<Object> type_handle = Factory::NewStringFromAscii(CStrVector(type));
   Handle<Object> args[2] = { type_handle, name };
   Handle<Object> error =
       Factory::NewTypeError("redeclaration", HandleVector(args, 2));
   return Top::Throw(*error);
 }
 
 
@@ skipping 5438 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage();
   }
 }
 
 
 } }  // namespace v8::internal