Fix map compact implementation....

src/mark-compact.cc

 // Copyright 2006-2008 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 1273 matching lines @@
   void UpdateMapPointersInRoots() {
     Heap::IterateRoots(&map_updating_visitor_, VISIT_ONLY_STRONG);
     GlobalHandles::IterateWeakRoots(&map_updating_visitor_);
   }
 
   void FinishMapSpace() {
     // Iterate through to space and finish move.
     MapIterator it;
     HeapObject* o = it.next();
     for (; o != first_map_to_evacuate_; o = it.next()) {
+      it.has_next();

[Søren Thygesen Gjesse, 2010/01/21 07:57:41]

Please add a comment here.

+      ASSERT(it.has_next());
       Map* map = reinterpret_cast<Map*>(o);
       ASSERT(!map->IsMarked());
       ASSERT(!map->IsOverflowed());
       ASSERT(map->IsMap());
       Heap::UpdateRSet(map);
     }
   }
 
   void UpdateMapPointersInPagedSpace(PagedSpace* space) {
     ASSERT(space != Heap::map_space());
@@ skipping 51 matching lines @@
       if (!map_word.IsOverflowed()) return;
 
       *p = GetForwardedMap(map_word);
     }
   };
 
   static MapUpdatingVisitor map_updating_visitor_;
 
   static Map* NextMap(MapIterator* it, HeapObject* last, bool live) {
     while (true) {
+      it->has_next();  // Need to be called for side effects.
       ASSERT(it->has_next());
       HeapObject* next = it->next();
       if (next == last)
         return NULL;
       ASSERT(!next->IsOverflowed());
       ASSERT(!next->IsMarked());
       ASSERT(next->IsMap() || FreeListNode::IsFreeListNode(next));
       if (next->IsMap() == live)
         return reinterpret_cast<Map*>(next);
     }
@@ skipping 620 matching lines @@
 
 void MarkCompactCollector::RebuildRSets() {
 #ifdef DEBUG
   ASSERT(state_ == RELOCATE_OBJECTS);
   state_ = REBUILD_RSETS;
 #endif
   Heap::RebuildRSets();
 }
 
 } }  // namespace v8::internal