Allow hidden properties and implement GetIdentityHash

src/objects.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 5153 matching lines @@
             Smi::cast(JSArray::cast(this)->length())->value()) :
         static_cast<uint32_t>(FixedArray::cast(elements())->length());
     return (index < length) &&
            !FixedArray::cast(elements())->get(index)->IsTheHole();
   } else {
     return element_dictionary()->FindNumberEntry(index) != -1;
   }
 }
 
 
+Object* JSObject::GetHiddenProperties(bool create_if_needed) {
+  String* key = Heap::hidden_symbol();
+  if (!this->HasProperty(key)) {
+    // Hidden properties object not found. Allocate a new hidden properties
+    // object if requested. Otherwise return the undefined value.
+    if (create_if_needed) {
+      Object* obj = Heap::AllocateJSObject(
+          Top::context()->global_context()->object_function());
+      if (obj->IsFailure()) {
+        return obj;
+      }
+      return this->SetProperty(key, obj, DONT_ENUM);
+    } else {
+      return Heap::undefined_value();
+    }
+  }
+  return this->GetProperty(key);
+}
+
+
 bool JSObject::HasElementWithReceiver(JSObject* receiver, uint32_t index) {
   // Check access rights if needed.
   if (IsAccessCheckNeeded() &&
       !Top::MayIndexedAccess(this, index, v8::ACCESS_HAS)) {
     Top::ReportFailedAccessCheck(this, v8::ACCESS_HAS);
     return false;
   }
 
   // Check for lookup interceptor
   if (HasIndexedInterceptor()) {
@@ skipping 2180 matching lines @@
   // No break point.
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 
 
 } }  // namespace v8::internal