Use symbols instead of hidden properties for i18n markers.

src/runtime/runtime-i18n.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 #ifdef V8_I18N_SUPPORT
 #include "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/i18n.h"
@@ skipping 215 matching lines @@
 RUNTIME_FUNCTION(Runtime_IsInitializedIntlObject) {
   HandleScope scope(isolate);
 
   DCHECK(args.length() == 1);
 
   CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
 
   if (!input->IsJSObject()) return isolate->heap()->false_value();
   Handle<JSObject> obj = Handle<JSObject>::cast(input);
 
-  Handle<String> marker = isolate->factory()->intl_initialized_marker_string();
-  Handle<Object> tag(obj->GetHiddenProperty(marker), isolate);
-  return isolate->heap()->ToBoolean(!tag->IsTheHole());
+  Handle<Symbol> marker = isolate->factory()->intl_initialized_marker_symbol();
+  Handle<Object> tag = JSObject::GetDataProperty(obj, marker);
+  return isolate->heap()->ToBoolean(!tag->IsUndefined());
 }
 
 
 RUNTIME_FUNCTION(Runtime_IsInitializedIntlObjectOfType) {
   HandleScope scope(isolate);
 
   DCHECK(args.length() == 2);
 
   CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, expected_type, 1);
 
   if (!input->IsJSObject()) return isolate->heap()->false_value();
   Handle<JSObject> obj = Handle<JSObject>::cast(input);
 
-  Handle<String> marker = isolate->factory()->intl_initialized_marker_string();
-  Handle<Object> tag(obj->GetHiddenProperty(marker), isolate);
+  Handle<Symbol> marker = isolate->factory()->intl_initialized_marker_symbol();
+  Handle<Object> tag = JSObject::GetDataProperty(obj, marker);
   return isolate->heap()->ToBoolean(tag->IsString() &&
                                     String::cast(*tag)->Equals(*expected_type));
 }
 
 
 RUNTIME_FUNCTION(Runtime_MarkAsInitializedIntlObjectOfType) {
   HandleScope scope(isolate);
 
   DCHECK(args.length() == 3);
 
   CONVERT_ARG_HANDLE_CHECKED(JSObject, input, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, type, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, impl, 2);
 
-  Handle<String> marker = isolate->factory()->intl_initialized_marker_string();
-  JSObject::SetHiddenProperty(input, marker, type);
+  Handle<Symbol> marker = isolate->factory()->intl_initialized_marker_symbol();
+  JSObject::SetProperty(input, marker, type, STRICT).Assert();
 
-  marker = isolate->factory()->intl_impl_object_string();
-  JSObject::SetHiddenProperty(input, marker, impl);
+  marker = isolate->factory()->intl_impl_object_symbol();
+  JSObject::SetProperty(input, marker, impl, STRICT).Assert();
 
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_GetImplFromInitializedIntlObject) {
   HandleScope scope(isolate);
 
   DCHECK(args.length() == 1);
 
   CONVERT_ARG_HANDLE_CHECKED(Object, input, 0);
 
   if (!input->IsJSObject()) {
     Vector<Handle<Object> > arguments = HandleVector(&input, 1);
     THROW_NEW_ERROR_RETURN_FAILURE(isolate,
                                    NewTypeError("not_intl_object", arguments));
   }
 
   Handle<JSObject> obj = Handle<JSObject>::cast(input);
 
-  Handle<String> marker = isolate->factory()->intl_impl_object_string();
-  Handle<Object> impl(obj->GetHiddenProperty(marker), isolate);
+  Handle<Symbol> marker = isolate->factory()->intl_impl_object_symbol();
+
+  Handle<Object> impl = JSObject::GetDataProperty(obj, marker);
   if (impl->IsTheHole()) {
     Vector<Handle<Object> > arguments = HandleVector(&obj, 1);
     THROW_NEW_ERROR_RETURN_FAILURE(isolate,
                                    NewTypeError("not_intl_object", arguments));
   }
   return *impl;
 }
 
 
 RUNTIME_FUNCTION(Runtime_CreateDateTimeFormat) {
@@ skipping 436 matching lines @@
   } else if (status >= UBRK_WORD_IDEO && status < UBRK_WORD_IDEO_LIMIT) {
     return *isolate->factory()->NewStringFromStaticChars("ideo");
   } else {
     return *isolate->factory()->NewStringFromStaticChars("unknown");
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_I18N_SUPPORT