Define DEBUG for v8_optimized_debug=2

src/incremental-marking.cc

 // Copyright 2012 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 710 matching lines @@
 
 void IncrementalMarking::VisitObject(Map* map, HeapObject* obj, int size) {
   MarkBit map_mark_bit = Marking::MarkBitFrom(map);
   if (Marking::IsWhite(map_mark_bit)) {
     WhiteToGreyAndPush(map, map_mark_bit);
   }
 
   IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
 
   MarkBit mark_bit = Marking::MarkBitFrom(obj);
-#ifdef DEBUG
+#if ENABLE_SLOW_ASSERTS
   MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
   SLOW_ASSERT(Marking::IsGrey(mark_bit) ||
               (obj->IsFiller() && Marking::IsWhite(mark_bit)) ||
               (chunk->IsFlagSet(MemoryChunk::HAS_PROGRESS_BAR) &&
                Marking::IsBlack(mark_bit)));
 #endif
   MarkBlackOrKeepBlack(obj, mark_bit, size);
 }
 
 
@@ skipping 293 matching lines @@
   bytes_scanned_ = 0;
   write_barriers_invoked_since_last_step_ = 0;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSizeOfObjects();
 }
 
 } }  // namespace v8::internal