[heap] Move slot recording of weak fields in native context to native context list retainer.

src/heap/objects-visiting.cc

 // Copyright 2011 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.
 
 #include "src/heap/objects-visiting.h"
 
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/objects-visiting-inl.h"
 
 namespace v8 {
@@ skipping 289 matching lines @@
   static int WeakNextOffset() {
     return FixedArray::SizeFor(Context::NEXT_CONTEXT_LINK);
   }
 
   static void VisitLiveObject(Heap* heap, Context* context,
                               WeakObjectRetainer* retainer) {
     // Process the three weak lists linked off the context.
     DoWeakList<JSFunction>(heap, context, retainer,
                            Context::OPTIMIZED_FUNCTIONS_LIST);
 
-    // Code objects are always allocated in Code space, we do not have to visit
-    // them during scavenges.
     if (heap->gc_state() == Heap::MARK_COMPACT) {
+      // Record the slots of the weak entries in the native context.
+      MarkCompactCollector* collector = heap->mark_compact_collector();
+      for (int idx = Context::FIRST_WEAK_SLOT;
+           idx < Context::NATIVE_CONTEXT_SLOTS; ++idx) {
+        Object** slot = Context::cast(context)->RawFieldOfElementAt(idx);
+        collector->RecordSlot(context, slot, *slot);
+      }
+      // Code objects are always allocated in Code space, we do not have to
+      // visit
+      // them during scavenges.
       DoWeakList<Code>(heap, context, retainer, Context::OPTIMIZED_CODE_LIST);
       DoWeakList<Code>(heap, context, retainer, Context::DEOPTIMIZED_CODE_LIST);
     }
   }
 
   template <class T>
   static void DoWeakList(Heap* heap, Context* context,
                          WeakObjectRetainer* retainer, int index) {
     // Visit the weak list, removing dead intermediate elements.
     Object* list_head = VisitWeakList<T>(heap, context->get(index), retainer);
@@ skipping 34 matching lines @@
 };
 
 
 template Object* VisitWeakList<Context>(Heap* heap, Object* list,
                                         WeakObjectRetainer* retainer);
 
 template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list,
                                                WeakObjectRetainer* retainer);
 }  // namespace internal
 }  // namespace v8