Create an abstraction (MarkBit) object to hold the location of the...

src/objects.cc

 // Copyright 2010 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 5419 matching lines @@
     // If the pair (value, details) is a map transition,
     // check if the target is live.  If not, null the descriptor.
     // Also drop the back pointer for that map transition, so that this
     // map is not reached again by following a back pointer from a
     // non-live object.
     PropertyDetails details(Smi::cast(contents->get(i + 1)));
     if (details.type() == MAP_TRANSITION ||
         details.type() == CONSTANT_TRANSITION) {
       Map* target = reinterpret_cast<Map*>(contents->get(i));
       ASSERT(target->IsHeapObject());
-      if (!Marking::IsMarked(target)) {
+      MarkBit map_mark = Marking::MarkBitFrom(target);
+      if (!map_mark.Get()) {
         ASSERT(target->IsMap());
         contents->set_unchecked(i + 1, NullDescriptorDetails);
         contents->set_null_unchecked(i);
         ASSERT(target->prototype() == this ||
                target->prototype() == real_prototype);
         // Getter prototype() is read-only, set_prototype() has side effects.
         *RawField(target, Map::kPrototypeOffset) = real_prototype;
       }
     }
   }
@@ skipping 4596 matching lines @@
   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();
 }
 #endif
 
 
 } }  // namespace v8::internal