[heap] Minor MC: Add marking

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 89f1b61281a40fc709a63b2b3bbb137f2b6ddcf1..87c8b28f4b504bc187a6b14b1f8ef39085b7cec7 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1321,7 +1321,26 @@ bool Heap::PerformGarbageCollection(
         MinorMarkCompact();
         break;
       case SCAVENGER:
+#ifdef VERIFY_HEAP
+        std::vector<HeapObject*> objects_in_to_space;
+        if (FLAG_verify_minor_mc_marking) {
+          objects_in_to_space = mark_compact_collector()->GetObjectsInToSpace();
+          mark_compact_collector()->MarkYoungGenerationForVerification();
+          isolate()->global_handles()->ResetNewSpaceHandlesForTesting();
+        }
+#endif  // VERIFY_HEAP
         Scavenge();
+#ifdef VERIFY_HEAP
+        if (FLAG_verify_minor_mc_marking) {
+          mark_compact_collector()
+              ->VerifyYoungGenerationMarkbitsUsingForwardingPointers(
+                  objects_in_to_space);
+          for (Page* p : NewSpacePageRange(new_space()->FromSpaceStart(),
+                                           new_space()->FromSpaceEnd())) {
+            p->ClearLiveness();
+          }
+        }
+#endif  // VERIFY_HEAP
         break;
     }
 
@@ -1502,21 +1521,6 @@ static bool IsUnscavengedHeapObject(Heap* heap, Object** p) {
          !HeapObject::cast(*p)->map_word().IsForwardingAddress();
 }
 
-
-static bool IsUnmodifiedHeapObject(Object** p) {
-  Object* object = *p;
-  if (object->IsSmi()) return false;
-  HeapObject* heap_object = HeapObject::cast(object);
-  if (!object->IsJSObject()) return false;
-  JSObject* js_object = JSObject::cast(object);
-  if (!js_object->WasConstructedFromApiFunction()) return false;
-  JSFunction* constructor =
-      JSFunction::cast(js_object->map()->GetConstructor());
-
-  return constructor->initial_map() == heap_object->map();
-}
-
-
 void PromotionQueue::Initialize() {
   // The last to-space page may be used for promotion queue. On promotion
   // conflict, we use the emergency stack.
@@ -1691,8 +1695,10 @@ void Heap::Scavenge() {
   isolate()->global_handles()->MarkNewSpaceWeakUnmodifiedObjectsPending(
       &IsUnscavengedHeapObject);
 
-  isolate()->global_handles()->IterateNewSpaceWeakUnmodifiedRoots(
-      &scavenge_visitor);
+  isolate()
+      ->global_handles()
+      ->IterateNewSpaceWeakUnmodifiedRoots<GlobalHandles::HANDLE_PHANTOM_NODES>(
+          &scavenge_visitor);
   new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
 
   UpdateNewSpaceReferencesInExternalStringTable(
@@ -2904,6 +2910,18 @@ bool Heap::RootCanBeTreatedAsConstant(RootListIndex root_index) {
          !InNewSpace(root(root_index));
 }
 
+bool Heap::IsUnmodifiedHeapObject(Object** p) {
+  Object* object = *p;
+  if (object->IsSmi()) return false;
+  HeapObject* heap_object = HeapObject::cast(object);
+  if (!object->IsJSObject()) return false;
+  JSObject* js_object = JSObject::cast(object);
+  if (!js_object->WasConstructedFromApiFunction()) return false;
+  JSFunction* constructor =
+      JSFunction::cast(js_object->map()->GetConstructor());
+
+  return constructor->initial_map() == heap_object->map();
+}
 
 int Heap::FullSizeNumberStringCacheLength() {
   // Compute the size of the number string cache based on the max newspace size.