Provide baseline for experimental GC implementation.

test/cctest/test-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 210 matching lines @@
   CHECK(Top::context()->global()->
             GetProperty(obj_name)->ToObjectChecked()->IsJSObject());
   obj = JSObject::cast(
       Top::context()->global()->GetProperty(obj_name)->ToObjectChecked());
   prop_name =
       String::cast(Heap::LookupAsciiSymbol("theSlot")->ToObjectChecked());
   CHECK(obj->GetProperty(prop_name)->ToObjectChecked() == Smi::FromInt(23));
 }
 
 
+// TODO(gc): compaction of map space is temporary removed from GC.
+#if 0
 static Handle<Map> CreateMap() {
   return Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
 }
 
 
 TEST(MapCompact) {
   FLAG_max_map_space_pages = 16;
   InitializeVM();
 
   {
     v8::HandleScope sc;
     // keep allocating maps while pointers are still encodable and thus
     // mark compact is permitted.
     Handle<JSObject> root = Factory::NewJSObjectFromMap(CreateMap());
     do {
       Handle<Map> map = CreateMap();
       map->set_prototype(*root);
       root = Factory::NewJSObjectFromMap(map);
     } while (Heap::map_space()->MapPointersEncodable());
   }
   // Now, as we don't have any handles to just allocated maps, we should
   // be able to trigger map compaction.
   // To give an additional chance to fail, try to force compaction which
   // should be impossible right now.
   Heap::CollectAllGarbage(true);
   // And now map pointers should be encodable again.
   CHECK(Heap::map_space()->MapPointersEncodable());
 }
-
+#endif
 
 static int gc_starts = 0;
 static int gc_ends = 0;
 
 static void GCPrologueCallbackFunc() {
   CHECK(gc_starts == gc_ends);
   gc_starts++;
 }
 
 
@@ skipping 84 matching lines @@
     Object** g2_objects[] = { g2s1.location(), g2s2.location() };
     GlobalHandles::AddGroup(g1_objects, 2);
     GlobalHandles::AddGroup(g2_objects, 2);
   }
 
   Heap::CollectGarbage(OLD_POINTER_SPACE);
 
   // All objects should be gone. 5 global handles in total.
   CHECK_EQ(5, NumberOfWeakCalls);
 }