Replace ad-hoc weakness in transition array with WeakCell.

src/heap/objects-visiting-inl.h

 // Copyright 2012 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.
 
 #ifndef V8_OBJECTS_VISITING_INL_H_
 #define V8_OBJECTS_VISITING_INL_H_
 
 #include "src/heap/objects-visiting.h"
 
 namespace v8 {
@@ skipping 519 matching lines @@
   StaticVisitor::VisitPointers(
       map->GetHeap(),
       HeapObject::RawField(object, JSDataView::BodyDescriptor::kStartOffset),
       HeapObject::RawField(object, JSDataView::kSizeWithInternalFields));
 }
 
 
 template <typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::MarkMapContents(Heap* heap,
                                                           Map* map) {
-  Object* raw_transitions = map->raw_transitions();
-  if (TransitionArray::IsFullTransitionArray(raw_transitions)) {
-    MarkTransitionArray(heap, TransitionArray::cast(raw_transitions));
-  }
-
   // Since descriptor arrays are potentially shared, ensure that only the
   // descriptors that belong to this map are marked. The first time a
   // non-empty descriptor array is marked, its header is also visited. The slot
   // holding the descriptor array will be implicitly recorded when the pointer
   // fields of this map are visited.
   DescriptorArray* descriptors = map->instance_descriptors();
   if (StaticVisitor::MarkObjectWithoutPush(heap, descriptors) &&
       descriptors->length() > 0) {
     StaticVisitor::VisitPointers(heap, descriptors->GetFirstElementAddress(),
                                  descriptors->GetDescriptorEndSlot(0));
   }
   int start = 0;
   int end = map->NumberOfOwnDescriptors();
   if (start < end) {
     StaticVisitor::VisitPointers(heap,
                                  descriptors->GetDescriptorStartSlot(start),
                                  descriptors->GetDescriptorEndSlot(end));
   }
 
   // Mark the pointer fields of the Map. Since the transitions array has
   // been marked already, it is fine that one of these fields contains a
   // pointer to it.
   StaticVisitor::VisitPointers(
       heap, HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
       HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
 }
 
 
 template <typename StaticVisitor>
-void StaticMarkingVisitor<StaticVisitor>::MarkTransitionArray(
-    Heap* heap, TransitionArray* transitions) {
-  if (!StaticVisitor::MarkObjectWithoutPush(heap, transitions)) return;
-
-  if (transitions->HasPrototypeTransitions()) {
-    StaticVisitor::VisitPointer(heap,
-                                transitions->GetPrototypeTransitionsSlot());
-  }
-
-  int num_transitions = TransitionArray::NumberOfTransitions(transitions);
-  for (int i = 0; i < num_transitions; ++i) {
-    StaticVisitor::VisitPointer(heap, transitions->GetKeySlot(i));
-  }
-}
-
-
-template <typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::MarkInlinedFunctionsCode(Heap* heap,
                                                                    Code* code) {
   // For optimized functions we should retain both non-optimized version
   // of its code and non-optimized version of all inlined functions.
   // This is required to support bailing out from inlined code.
   DeoptimizationInputData* const data =
       DeoptimizationInputData::cast(code->deoptimization_data());
   FixedArray* const literals = data->LiteralArray();
   int const inlined_count = data->InlinedFunctionCount()->value();
   for (int i = 0; i < inlined_count; ++i) {
@@ skipping 235 matching lines @@
 
   RelocIterator it(this, mode_mask);
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>(heap);
   }
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_INL_H_