Turn on DCHECKs and other debugging code if dcheck_always_on is 1

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 6530 matching lines @@
 
 void JSRegExp::SetDataAt(int index, Object* value) {
   DCHECK(TypeTag() != NOT_COMPILED);
   DCHECK(index >= kDataIndex);  // Only implementation data can be set this way.
   FixedArray::cast(data())->set(index, value);
 }
 
 
 ElementsKind JSObject::GetElementsKind() {
   ElementsKind kind = map()->elements_kind();
-#if DEBUG
+#if VERIFY_HEAP
   FixedArrayBase* fixed_array =
       reinterpret_cast<FixedArrayBase*>(READ_FIELD(this, kElementsOffset));
 
   // If a GC was caused while constructing this object, the elements
   // pointer may point to a one pointer filler map.
   if (ElementsAreSafeToExamine()) {
     Map* map = fixed_array->map();
     DCHECK((IsFastSmiOrObjectElementsKind(kind) &&
             (map == GetHeap()->fixed_array_map() ||
              map == GetHeap()->fixed_cow_array_map())) ||
@@ skipping 953 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_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_