Add counters that automatically track object sizes and counts.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index e61457991e1769c6a589d1c40c7550de5f9854b2..024b7ef4072ca162ebe9ca8750a1a6d3e885f42d 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -944,6 +944,17 @@ class StaticMarkingVisitor : public StaticVisitorBase {
     table_.GetVisitor(map)(map, obj);
   }
 
+  template<int id>
+  class ObjectStatsTracker {
+   public:
+    static inline void Visit(Map* map, HeapObject* obj) {
+      Heap* heap = map->GetHeap();
+      int object_size = obj->Size();
+      heap->RecordObjectStats(map->instance_type(), object_size);
+      non_count_table_.GetVisitorById(static_cast<VisitorId>(id))(map, obj);
+    }
+  };
+
   static void Initialize() {
     table_.Register(kVisitShortcutCandidate,
                     &FixedBodyVisitor<StaticMarkingVisitor,
@@ -1012,6 +1023,15 @@ class StaticMarkingVisitor : public StaticVisitorBase {
     table_.RegisterSpecializations<StructObjectVisitor,
                                    kVisitStruct,
                                    kVisitStructGeneric>();
+
+    if (FLAG_track_gc_object_stats) {
+      // Copy the visitor table to make call-through possible.
+      non_count_table_.CopyFrom(&table_);
+#define VISITOR_ID_COUNT_FUNCTION(id)\
+      table_.Register(kVisit##id, ObjectStatsTracker<kVisit##id>::Visit);
+      VISITOR_ID_LIST(VISITOR_ID_COUNT_FUNCTION)
+#undef VISITOR_ID_COUNT_FUNCTION
+    }
   }
 
   INLINE(static void VisitPointer(Heap* heap, Object** p)) {
@@ -1557,11 +1577,14 @@ class StaticMarkingVisitor : public StaticVisitorBase {
   typedef void (*Callback)(Map* map, HeapObject* object);
 
   static VisitorDispatchTable<Callback> table_;
+  static VisitorDispatchTable<Callback> non_count_table_;
 };
 
 
 VisitorDispatchTable<StaticMarkingVisitor::Callback>
   StaticMarkingVisitor::table_;
+VisitorDispatchTable<StaticMarkingVisitor::Callback>
+  StaticMarkingVisitor::non_count_table_;
 
 
 class MarkingVisitor : public ObjectVisitor {
@@ -2437,6 +2460,10 @@ void MarkCompactCollector::AfterMarking() {
     // Clean up dead objects from the runtime profiler.
     heap()->isolate()->runtime_profiler()->RemoveDeadSamples();
   }
+
+  if (FLAG_track_gc_object_stats) {
+    heap()->CheckpointObjectStats();
+  }
 }