Add support for elements and array indices in Object.defineProperty...

src/runtime.cc

 // Copyright 2006-2009 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 608 matching lines @@
     }
 
     // This can potentially be an element in the elements dictionary or
     // a fast element.
     if (obj->HasDictionaryElements()) {
       NumberDictionary* dictionary = obj->element_dictionary();
       int entry = dictionary->FindEntry(index);
       PropertyDetails details = dictionary->DetailsAt(entry);
       elms->set(IS_ACCESSOR_INDEX, Heap::false_value());
       elms->set(VALUE_INDEX, dictionary->ValueAt(entry));
-      elms->set(WRITABLE_INDEX, Heap::ToBoolean(!details.IsDontDelete()));
+      elms->set(WRITABLE_INDEX, Heap::ToBoolean(!details.IsReadOnly()));
       elms->set(ENUMERABLE_INDEX, Heap::ToBoolean(!details.IsDontEnum()));
-      elms->set(CONFIGURABLE_INDEX, Heap::ToBoolean(!details.IsReadOnly()));
+      elms->set(CONFIGURABLE_INDEX, Heap::ToBoolean(!details.IsDontDelete()));
       return *desc;
     } else {
       // Elements that are stored as array elements always has:
       // writable: true, configurable: true, enumerable: true.
       elms->set(IS_ACCESSOR_INDEX, Heap::false_value());
       elms->set(VALUE_INDEX, obj->GetElement(index));
       elms->set(WRITABLE_INDEX, Heap::true_value());
       elms->set(ENUMERABLE_INDEX,  Heap::true_value());
       elms->set(CONFIGURABLE_INDEX, Heap::true_value());
       return *desc;
@@ skipping 3200 matching lines @@
   ASSERT(args.length() == 4);
   HandleScope scope;
   CONVERT_ARG_CHECKED(JSObject, js_object, 0);
   CONVERT_ARG_CHECKED(String, name, 1);
   Handle<Object> obj_value = args.at<Object>(2);
 
   CONVERT_CHECKED(Smi, flag, args[3]);
   int unchecked = flag->value();
   RUNTIME_ASSERT((unchecked & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
 
+  PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
+
+  // Check if this is an element.
+  uint32_t index;
+  bool is_element = name->AsArrayIndex(&index);
+
+  // Special case for elements if any of the flags are true.
+  // If elements are in fast case we always implicitly assume that:
+  // DONT_DELETE: false, DONT_ENUM: false, READ_ONLY: false.
+  if (((unchecked & (DONT_DELETE | DONT_ENUM | READ_ONLY)) != 0) &&
+      is_element) {
+    // Normalize the elements to enable attributes on the property.
+    js_object->NormalizeElements();
+    NumberDictionary* dictionary = js_object->element_dictionary();
+    // Make sure that we never go back to fast case.
+    dictionary->set_requires_slow_elements();
+    PropertyDetails details = PropertyDetails(attr, NORMAL);
+    dictionary->Set(index, *obj_value, details);
+  }
+
   LookupResult result;
   js_object->LocalLookupRealNamedProperty(*name, &result);
 
-  PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
-
   // Take special care when attributes are different and there is already
   // a property. For simplicity we normalize the property which enables us
   // to not worry about changing the instance_descriptor and creating a new
   // map. The current version of SetObjectProperty does not handle attributes
   // correctly in the case where a property is a field and is reset with
   // new attributes.
   if (result.IsProperty() && attr != result.GetAttributes()) {
     // New attributes - normalize to avoid writing to instance descriptor
     js_object->NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0);
     // Use IgnoreAttributes version since a readonly property may be
     // overridden and SetProperty does not allow this.
     return js_object->IgnoreAttributesAndSetLocalProperty(*name,
                                                           *obj_value,
                                                           attr);
   }
+
   return Runtime::SetObjectProperty(js_object, name, obj_value, attr);
 }
 
 
 Object* Runtime::SetObjectProperty(Handle<Object> object,
                                    Handle<Object> key,
                                    Handle<Object> value,
                                    PropertyAttributes attr) {
   HandleScope scope;
 
@@ skipping 6490 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(false);
   }
 }
 
 
 } }  // namespace v8::internal