Use DescriptorArray when checking if an object has a property

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 6988 matching lines @@
 
 
 Maybe<bool> JSReceiver::HasProperty(Handle<JSReceiver> object,
                                     Handle<Name> name) {
   // Call the "has" trap on proxies.
   if (object->IsJSProxy()) {
     Handle<JSProxy> proxy = Handle<JSProxy>::cast(object);
     return JSProxy::HasPropertyWithHandler(proxy, name);
   }
 
+  DescriptorArray* desc;
+  PrototypeIterator iter(object->GetIsolate(), *object,
+      PrototypeIterator::START_AT_RECEIVER);
+  while (!iter.IsAtEnd()) {
+    if (iter.GetCurrent()->IsJSObject()) {
+      JSReceiver* prototype_object = JSReceiver::cast(iter.GetCurrent());
+      desc = prototype_object->map()->instance_descriptors();
+      if (!desc->IsEmpty()) {
+        int there = desc->SearchWithCache(*name, prototype_object->map());
+        if (there != desc->kNotFound)
+          return Just(true);
+      }
+    }
+    iter.Advance();
+  }
+
   Maybe<PropertyAttributes> result = GetPropertyAttributes(object, name);
   return result.IsJust() ? Just(result.FromJust() != ABSENT) : Nothing<bool>();
 }
 
 
 Maybe<bool> JSReceiver::HasOwnProperty(Handle<JSReceiver> object,
                                        Handle<Name> name) {
   // Call the "has" trap on proxies.
   if (object->IsJSProxy()) {
     Handle<JSProxy> proxy = Handle<JSProxy>::cast(object);
@@ skipping 833 matching lines @@
 #undef READ_INT64_FIELD
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_