deps: update v8 to 3.28.73

Reviewed-By: Fedor Indutny <fedor@indutny.com>
PR-URL: https://github.com/joyent/node/pull/8476

1 files changed, 932 insertions, 0 deletions

diff --git a/deps/v8/src/heap/objects-visiting-inl.h b/deps/v8/src/heap/objects-visiting-inl.h
new file mode 100644
index 0000000000..8846d27bce
--- /dev/null
+++ b/deps/v8/src/heap/objects-visiting-inl.h
@@ -0,0 +1,932 @@
+// 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_
+
+
+namespace v8 {
+namespace internal {
+
+template <typename StaticVisitor>
+void StaticNewSpaceVisitor<StaticVisitor>::Initialize() {
+  table_.Register(
+      kVisitShortcutCandidate,
+      &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor, int>::Visit);
+
+  table_.Register(
+      kVisitConsString,
+      &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor, int>::Visit);
+
+  table_.Register(kVisitSlicedString,
+                  &FixedBodyVisitor<StaticVisitor, SlicedString::BodyDescriptor,
+                                    int>::Visit);
+
+  table_.Register(
+      kVisitSymbol,
+      &FixedBodyVisitor<StaticVisitor, Symbol::BodyDescriptor, int>::Visit);
+
+  table_.Register(kVisitFixedArray,
+                  &FlexibleBodyVisitor<StaticVisitor,
+                                       FixedArray::BodyDescriptor, int>::Visit);
+
+  table_.Register(kVisitFixedDoubleArray, &VisitFixedDoubleArray);
+  table_.Register(kVisitFixedTypedArray, &VisitFixedTypedArray);
+  table_.Register(kVisitFixedFloat64Array, &VisitFixedTypedArray);
+
+  table_.Register(
+      kVisitNativeContext,
+      &FixedBodyVisitor<StaticVisitor, Context::ScavengeBodyDescriptor,
+                        int>::Visit);
+
+  table_.Register(kVisitByteArray, &VisitByteArray);
+
+  table_.Register(
+      kVisitSharedFunctionInfo,
+      &FixedBodyVisitor<StaticVisitor, SharedFunctionInfo::BodyDescriptor,
+                        int>::Visit);
+
+  table_.Register(kVisitSeqOneByteString, &VisitSeqOneByteString);
+
+  table_.Register(kVisitSeqTwoByteString, &VisitSeqTwoByteString);
+
+  table_.Register(kVisitJSFunction, &VisitJSFunction);
+
+  table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer);
+
+  table_.Register(kVisitJSTypedArray, &VisitJSTypedArray);
+
+  table_.Register(kVisitJSDataView, &VisitJSDataView);
+
+  table_.Register(kVisitFreeSpace, &VisitFreeSpace);
+
+  table_.Register(kVisitJSWeakCollection, &JSObjectVisitor::Visit);
+
+  table_.Register(kVisitJSRegExp, &JSObjectVisitor::Visit);
+
+  table_.template RegisterSpecializations<DataObjectVisitor, kVisitDataObject,
+                                          kVisitDataObjectGeneric>();
+
+  table_.template RegisterSpecializations<JSObjectVisitor, kVisitJSObject,
+                                          kVisitJSObjectGeneric>();
+  table_.template RegisterSpecializations<StructVisitor, kVisitStruct,
+                                          kVisitStructGeneric>();
+}
+
+
+template <typename StaticVisitor>
+int StaticNewSpaceVisitor<StaticVisitor>::VisitJSArrayBuffer(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+
+  STATIC_ASSERT(JSArrayBuffer::kWeakFirstViewOffset ==
+                JSArrayBuffer::kWeakNextOffset + kPointerSize);
+  VisitPointers(heap, HeapObject::RawField(
+                          object, JSArrayBuffer::BodyDescriptor::kStartOffset),
+                HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset));
+  VisitPointers(
+      heap, HeapObject::RawField(
+                object, JSArrayBuffer::kWeakNextOffset + 2 * kPointerSize),
+      HeapObject::RawField(object, JSArrayBuffer::kSizeWithInternalFields));
+  return JSArrayBuffer::kSizeWithInternalFields;
+}
+
+
+template <typename StaticVisitor>
+int StaticNewSpaceVisitor<StaticVisitor>::VisitJSTypedArray(
+    Map* map, HeapObject* object) {
+  VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSTypedArray::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(object, JSTypedArray::kWeakNextOffset));
+  VisitPointers(
+      map->GetHeap(), HeapObject::RawField(
+                          object, JSTypedArray::kWeakNextOffset + kPointerSize),
+      HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields));
+  return JSTypedArray::kSizeWithInternalFields;
+}
+
+
+template <typename StaticVisitor>
+int StaticNewSpaceVisitor<StaticVisitor>::VisitJSDataView(Map* map,
+                                                          HeapObject* object) {
+  VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSDataView::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(object, JSDataView::kWeakNextOffset));
+  VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSDataView::kWeakNextOffset + kPointerSize),
+      HeapObject::RawField(object, JSDataView::kSizeWithInternalFields));
+  return JSDataView::kSizeWithInternalFields;
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::Initialize() {
+  table_.Register(kVisitShortcutCandidate,
+                  &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor,
+                                    void>::Visit);
+
+  table_.Register(kVisitConsString,
+                  &FixedBodyVisitor<StaticVisitor, ConsString::BodyDescriptor,
+                                    void>::Visit);
+
+  table_.Register(kVisitSlicedString,
+                  &FixedBodyVisitor<StaticVisitor, SlicedString::BodyDescriptor,
+                                    void>::Visit);
+
+  table_.Register(
+      kVisitSymbol,
+      &FixedBodyVisitor<StaticVisitor, Symbol::BodyDescriptor, void>::Visit);
+
+  table_.Register(kVisitFixedArray, &FixedArrayVisitor::Visit);
+
+  table_.Register(kVisitFixedDoubleArray, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitFixedTypedArray, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitFixedFloat64Array, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitConstantPoolArray, &VisitConstantPoolArray);
+
+  table_.Register(kVisitNativeContext, &VisitNativeContext);
+
+  table_.Register(kVisitAllocationSite, &VisitAllocationSite);
+
+  table_.Register(kVisitByteArray, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitFreeSpace, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitSeqOneByteString, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitSeqTwoByteString, &DataObjectVisitor::Visit);
+
+  table_.Register(kVisitJSWeakCollection, &VisitWeakCollection);
+
+  table_.Register(
+      kVisitOddball,
+      &FixedBodyVisitor<StaticVisitor, Oddball::BodyDescriptor, void>::Visit);
+
+  table_.Register(kVisitMap, &VisitMap);
+
+  table_.Register(kVisitCode, &VisitCode);
+
+  table_.Register(kVisitSharedFunctionInfo, &VisitSharedFunctionInfo);
+
+  table_.Register(kVisitJSFunction, &VisitJSFunction);
+
+  table_.Register(kVisitJSArrayBuffer, &VisitJSArrayBuffer);
+
+  table_.Register(kVisitJSTypedArray, &VisitJSTypedArray);
+
+  table_.Register(kVisitJSDataView, &VisitJSDataView);
+
+  // Registration for kVisitJSRegExp is done by StaticVisitor.
+
+  table_.Register(
+      kVisitCell,
+      &FixedBodyVisitor<StaticVisitor, Cell::BodyDescriptor, void>::Visit);
+
+  table_.Register(kVisitPropertyCell, &VisitPropertyCell);
+
+  table_.template RegisterSpecializations<DataObjectVisitor, kVisitDataObject,
+                                          kVisitDataObjectGeneric>();
+
+  table_.template RegisterSpecializations<JSObjectVisitor, kVisitJSObject,
+                                          kVisitJSObjectGeneric>();
+
+  table_.template RegisterSpecializations<StructObjectVisitor, kVisitStruct,
+                                          kVisitStructGeneric>();
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeEntry(
+    Heap* heap, Address entry_address) {
+  Code* code = Code::cast(Code::GetObjectFromEntryAddress(entry_address));
+  heap->mark_compact_collector()->RecordCodeEntrySlot(entry_address, code);
+  StaticVisitor::MarkObject(heap, code);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitEmbeddedPointer(
+    Heap* heap, RelocInfo* rinfo) {
+  DCHECK(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
+  HeapObject* object = HeapObject::cast(rinfo->target_object());
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, object);
+  // TODO(ulan): It could be better to record slots only for strongly embedded
+  // objects here and record slots for weakly embedded object during clearing
+  // of non-live references in mark-compact.
+  if (!rinfo->host()->IsWeakObject(object)) {
+    StaticVisitor::MarkObject(heap, object);
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCell(Heap* heap,
+                                                    RelocInfo* rinfo) {
+  DCHECK(rinfo->rmode() == RelocInfo::CELL);
+  Cell* cell = rinfo->target_cell();
+  // No need to record slots because the cell space is not compacted during GC.
+  if (!rinfo->host()->IsWeakObject(cell)) {
+    StaticVisitor::MarkObject(heap, cell);
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitDebugTarget(Heap* heap,
+                                                           RelocInfo* rinfo) {
+  DCHECK((RelocInfo::IsJSReturn(rinfo->rmode()) &&
+          rinfo->IsPatchedReturnSequence()) ||
+         (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
+          rinfo->IsPatchedDebugBreakSlotSequence()));
+  Code* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget(Heap* heap,
+                                                          RelocInfo* rinfo) {
+  DCHECK(RelocInfo::IsCodeTarget(rinfo->rmode()));
+  Code* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
+  // Monomorphic ICs are preserved when possible, but need to be flushed
+  // when they might be keeping a Context alive, or when the heap is about
+  // to be serialized.
+  if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub() &&
+      (target->ic_state() == MEGAMORPHIC || target->ic_state() == GENERIC ||
+       target->ic_state() == POLYMORPHIC || heap->flush_monomorphic_ics() ||
+       heap->isolate()->serializer_enabled() ||
+       target->ic_age() != heap->global_ic_age() ||
+       target->is_invalidated_weak_stub())) {
+    IC::Clear(heap->isolate(), rinfo->pc(), rinfo->host()->constant_pool());
+    target = Code::GetCodeFromTargetAddress(rinfo->target_address());
+  }
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCodeAgeSequence(
+    Heap* heap, RelocInfo* rinfo) {
+  DCHECK(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
+  Code* target = rinfo->code_age_stub();
+  DCHECK(target != NULL);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
+  StaticVisitor::MarkObject(heap, target);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitNativeContext(
+    Map* map, HeapObject* object) {
+  FixedBodyVisitor<StaticVisitor, Context::MarkCompactBodyDescriptor,
+                   void>::Visit(map, object);
+
+  MarkCompactCollector* collector = map->GetHeap()->mark_compact_collector();
+  for (int idx = Context::FIRST_WEAK_SLOT; idx < Context::NATIVE_CONTEXT_SLOTS;
+       ++idx) {
+    Object** slot = Context::cast(object)->RawFieldOfElementAt(idx);
+    collector->RecordSlot(slot, slot, *slot);
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitMap(Map* map,
+                                                   HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  Map* map_object = Map::cast(object);
+
+  // Clears the cache of ICs related to this map.
+  if (FLAG_cleanup_code_caches_at_gc) {
+    map_object->ClearCodeCache(heap);
+  }
+
+  // When map collection is enabled we have to mark through map's transitions
+  // and back pointers in a special way to make these links weak.
+  if (FLAG_collect_maps && map_object->CanTransition()) {
+    MarkMapContents(heap, map_object);
+  } else {
+    StaticVisitor::VisitPointers(
+        heap, HeapObject::RawField(object, Map::kPointerFieldsBeginOffset),
+        HeapObject::RawField(object, Map::kPointerFieldsEndOffset));
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitPropertyCell(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+
+  Object** slot =
+      HeapObject::RawField(object, PropertyCell::kDependentCodeOffset);
+  if (FLAG_collect_maps) {
+    // Mark property cell dependent codes array but do not push it onto marking
+    // stack, this will make references from it weak. We will clean dead
+    // codes when we iterate over property cells in ClearNonLiveReferences.
+    HeapObject* obj = HeapObject::cast(*slot);
+    heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+    StaticVisitor::MarkObjectWithoutPush(heap, obj);
+  } else {
+    StaticVisitor::VisitPointer(heap, slot);
+  }
+
+  StaticVisitor::VisitPointers(
+      heap,
+      HeapObject::RawField(object, PropertyCell::kPointerFieldsBeginOffset),
+      HeapObject::RawField(object, PropertyCell::kPointerFieldsEndOffset));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitAllocationSite(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+
+  Object** slot =
+      HeapObject::RawField(object, AllocationSite::kDependentCodeOffset);
+  if (FLAG_collect_maps) {
+    // Mark allocation site dependent codes array but do not push it onto
+    // marking stack, this will make references from it weak. We will clean
+    // dead codes when we iterate over allocation sites in
+    // ClearNonLiveReferences.
+    HeapObject* obj = HeapObject::cast(*slot);
+    heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+    StaticVisitor::MarkObjectWithoutPush(heap, obj);
+  } else {
+    StaticVisitor::VisitPointer(heap, slot);
+  }
+
+  StaticVisitor::VisitPointers(
+      heap,
+      HeapObject::RawField(object, AllocationSite::kPointerFieldsBeginOffset),
+      HeapObject::RawField(object, AllocationSite::kPointerFieldsEndOffset));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitWeakCollection(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  JSWeakCollection* weak_collection =
+      reinterpret_cast<JSWeakCollection*>(object);
+
+  // Enqueue weak collection in linked list of encountered weak collections.
+  if (weak_collection->next() == heap->undefined_value()) {
+    weak_collection->set_next(heap->encountered_weak_collections());
+    heap->set_encountered_weak_collections(weak_collection);
+  }
+
+  // Skip visiting the backing hash table containing the mappings and the
+  // pointer to the other enqueued weak collections, both are post-processed.
+  StaticVisitor::VisitPointers(
+      heap, HeapObject::RawField(object, JSWeakCollection::kPropertiesOffset),
+      HeapObject::RawField(object, JSWeakCollection::kTableOffset));
+  STATIC_ASSERT(JSWeakCollection::kTableOffset + kPointerSize ==
+                JSWeakCollection::kNextOffset);
+  STATIC_ASSERT(JSWeakCollection::kNextOffset + kPointerSize ==
+                JSWeakCollection::kSize);
+
+  // Partially initialized weak collection is enqueued, but table is ignored.
+  if (!weak_collection->table()->IsHashTable()) return;
+
+  // Mark the backing hash table without pushing it on the marking stack.
+  Object** slot = HeapObject::RawField(object, JSWeakCollection::kTableOffset);
+  HeapObject* obj = HeapObject::cast(*slot);
+  heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+  StaticVisitor::MarkObjectWithoutPush(heap, obj);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitCode(Map* map,
+                                                    HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  Code* code = Code::cast(object);
+  if (FLAG_age_code && !heap->isolate()->serializer_enabled()) {
+    code->MakeOlder(heap->mark_compact_collector()->marking_parity());
+  }
+  code->CodeIterateBody<StaticVisitor>(heap);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfo(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
+  if (shared->ic_age() != heap->global_ic_age()) {
+    shared->ResetForNewContext(heap->global_ic_age());
+  }
+  if (FLAG_cleanup_code_caches_at_gc) {
+    shared->ClearTypeFeedbackInfo();
+  }
+  if (FLAG_cache_optimized_code && FLAG_flush_optimized_code_cache &&
+      !shared->optimized_code_map()->IsSmi()) {
+    // Always flush the optimized code map if requested by flag.
+    shared->ClearOptimizedCodeMap();
+  }
+  MarkCompactCollector* collector = heap->mark_compact_collector();
+  if (collector->is_code_flushing_enabled()) {
+    if (FLAG_cache_optimized_code && !shared->optimized_code_map()->IsSmi()) {
+      // Add the shared function info holding an optimized code map to
+      // the code flusher for processing of code maps after marking.
+      collector->code_flusher()->AddOptimizedCodeMap(shared);
+      // Treat all references within the code map weakly by marking the
+      // code map itself but not pushing it onto the marking deque.
+      FixedArray* code_map = FixedArray::cast(shared->optimized_code_map());
+      StaticVisitor::MarkObjectWithoutPush(heap, code_map);
+    }
+    if (IsFlushable(heap, shared)) {
+      // This function's code looks flushable. But we have to postpone
+      // the decision until we see all functions that point to the same
+      // SharedFunctionInfo because some of them might be optimized.
+      // That would also make the non-optimized version of the code
+      // non-flushable, because it is required for bailing out from
+      // optimized code.
+      collector->code_flusher()->AddCandidate(shared);
+      // Treat the reference to the code object weakly.
+      VisitSharedFunctionInfoWeakCode(heap, object);
+      return;
+    }
+  } else {
+    if (FLAG_cache_optimized_code && !shared->optimized_code_map()->IsSmi()) {
+      // Flush optimized code map on major GCs without code flushing,
+      // needed because cached code doesn't contain breakpoints.
+      shared->ClearOptimizedCodeMap();
+    }
+  }
+  VisitSharedFunctionInfoStrongCode(heap, object);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitConstantPoolArray(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  ConstantPoolArray* array = ConstantPoolArray::cast(object);
+  ConstantPoolArray::Iterator code_iter(array, ConstantPoolArray::CODE_PTR);
+  while (!code_iter.is_finished()) {
+    Address code_entry = reinterpret_cast<Address>(
+        array->RawFieldOfElementAt(code_iter.next_index()));
+    StaticVisitor::VisitCodeEntry(heap, code_entry);
+  }
+
+  ConstantPoolArray::Iterator heap_iter(array, ConstantPoolArray::HEAP_PTR);
+  while (!heap_iter.is_finished()) {
+    Object** slot = array->RawFieldOfElementAt(heap_iter.next_index());
+    HeapObject* object = HeapObject::cast(*slot);
+    heap->mark_compact_collector()->RecordSlot(slot, slot, object);
+    bool is_weak_object =
+        (array->get_weak_object_state() ==
+             ConstantPoolArray::WEAK_OBJECTS_IN_OPTIMIZED_CODE &&
+         Code::IsWeakObjectInOptimizedCode(object)) ||
+        (array->get_weak_object_state() ==
+             ConstantPoolArray::WEAK_OBJECTS_IN_IC &&
+         Code::IsWeakObjectInIC(object));
+    if (!is_weak_object) {
+      StaticVisitor::MarkObject(heap, object);
+    }
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunction(Map* map,
+                                                          HeapObject* object) {
+  Heap* heap = map->GetHeap();
+  JSFunction* function = JSFunction::cast(object);
+  MarkCompactCollector* collector = heap->mark_compact_collector();
+  if (collector->is_code_flushing_enabled()) {
+    if (IsFlushable(heap, function)) {
+      // This function's code looks flushable. But we have to postpone
+      // the decision until we see all functions that point to the same
+      // SharedFunctionInfo because some of them might be optimized.
+      // That would also make the non-optimized version of the code
+      // non-flushable, because it is required for bailing out from
+      // optimized code.
+      collector->code_flusher()->AddCandidate(function);
+      // Visit shared function info immediately to avoid double checking
+      // of its flushability later. This is just an optimization because
+      // the shared function info would eventually be visited.
+      SharedFunctionInfo* shared = function->shared();
+      if (StaticVisitor::MarkObjectWithoutPush(heap, shared)) {
+        StaticVisitor::MarkObject(heap, shared->map());
+        VisitSharedFunctionInfoWeakCode(heap, shared);
+      }
+      // Treat the reference to the code object weakly.
+      VisitJSFunctionWeakCode(heap, object);
+      return;
+    } else {
+      // Visit all unoptimized code objects to prevent flushing them.
+      StaticVisitor::MarkObject(heap, function->shared()->code());
+      if (function->code()->kind() == Code::OPTIMIZED_FUNCTION) {
+        MarkInlinedFunctionsCode(heap, function->code());
+      }
+    }
+  }
+  VisitJSFunctionStrongCode(heap, object);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSRegExp(Map* map,
+                                                        HeapObject* object) {
+  int last_property_offset =
+      JSRegExp::kSize + kPointerSize * map->inobject_properties();
+  StaticVisitor::VisitPointers(
+      map->GetHeap(), HeapObject::RawField(object, JSRegExp::kPropertiesOffset),
+      HeapObject::RawField(object, last_property_offset));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSArrayBuffer(
+    Map* map, HeapObject* object) {
+  Heap* heap = map->GetHeap();
+
+  STATIC_ASSERT(JSArrayBuffer::kWeakFirstViewOffset ==
+                JSArrayBuffer::kWeakNextOffset + kPointerSize);
+  StaticVisitor::VisitPointers(
+      heap,
+      HeapObject::RawField(object, JSArrayBuffer::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(object, JSArrayBuffer::kWeakNextOffset));
+  StaticVisitor::VisitPointers(
+      heap, HeapObject::RawField(
+                object, JSArrayBuffer::kWeakNextOffset + 2 * kPointerSize),
+      HeapObject::RawField(object, JSArrayBuffer::kSizeWithInternalFields));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSTypedArray(
+    Map* map, HeapObject* object) {
+  StaticVisitor::VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSTypedArray::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(object, JSTypedArray::kWeakNextOffset));
+  StaticVisitor::VisitPointers(
+      map->GetHeap(), HeapObject::RawField(
+                          object, JSTypedArray::kWeakNextOffset + kPointerSize),
+      HeapObject::RawField(object, JSTypedArray::kSizeWithInternalFields));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSDataView(Map* map,
+                                                          HeapObject* object) {
+  StaticVisitor::VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSDataView::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(object, JSDataView::kWeakNextOffset));
+  StaticVisitor::VisitPointers(
+      map->GetHeap(),
+      HeapObject::RawField(object, JSDataView::kWeakNextOffset + kPointerSize),
+      HeapObject::RawField(object, JSDataView::kSizeWithInternalFields));
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::MarkMapContents(Heap* heap,
+                                                          Map* map) {
+  // Make sure that the back pointer stored either in the map itself or
+  // inside its transitions array is marked. Skip recording the back
+  // pointer slot since map space is not compacted.
+  StaticVisitor::MarkObject(heap, HeapObject::cast(map->GetBackPointer()));
+
+  // Treat pointers in the transitions array as weak and also mark that
+  // array to prevent visiting it later. Skip recording the transition
+  // array slot, since it will be implicitly recorded when the pointer
+  // fields of this map are visited.
+  if (map->HasTransitionArray()) {
+    TransitionArray* transitions = map->transitions();
+    MarkTransitionArray(heap, 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 prototype dependent codes array but do not push it onto marking
+  // stack, this will make references from it weak. We will clean dead
+  // codes when we iterate over maps in ClearNonLiveTransitions.
+  Object** slot = HeapObject::RawField(map, Map::kDependentCodeOffset);
+  HeapObject* obj = HeapObject::cast(*slot);
+  heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+  StaticVisitor::MarkObjectWithoutPush(heap, obj);
+
+  // 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;
+
+  // Simple transitions do not have keys nor prototype transitions.
+  if (transitions->IsSimpleTransition()) return;
+
+  if (transitions->HasPrototypeTransitions()) {
+    // Mark prototype transitions array but do not push it onto marking
+    // stack, this will make references from it weak. We will clean dead
+    // prototype transitions in ClearNonLiveTransitions.
+    Object** slot = transitions->GetPrototypeTransitionsSlot();
+    HeapObject* obj = HeapObject::cast(*slot);
+    heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
+    StaticVisitor::MarkObjectWithoutPush(heap, obj);
+  }
+
+  for (int i = 0; i < transitions->number_of_transitions(); ++i) {
+    StaticVisitor::VisitPointer(heap, transitions->GetKeySlot(i));
+  }
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::MarkInlinedFunctionsCode(Heap* heap,
+                                                                   Code* code) {
+  // Skip in absence of inlining.
+  // TODO(turbofan): Revisit once we support inlining.
+  if (code->is_turbofanned()) return;
+  // 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* data =
+      DeoptimizationInputData::cast(code->deoptimization_data());
+  FixedArray* literals = data->LiteralArray();
+  for (int i = 0, count = data->InlinedFunctionCount()->value(); i < count;
+       i++) {
+    JSFunction* inlined = JSFunction::cast(literals->get(i));
+    StaticVisitor::MarkObject(heap, inlined->shared()->code());
+  }
+}
+
+
+inline static bool IsValidNonBuiltinContext(Object* context) {
+  return context->IsContext() &&
+         !Context::cast(context)->global_object()->IsJSBuiltinsObject();
+}
+
+
+inline static bool HasSourceCode(Heap* heap, SharedFunctionInfo* info) {
+  Object* undefined = heap->undefined_value();
+  return (info->script() != undefined) &&
+         (reinterpret_cast<Script*>(info->script())->source() != undefined);
+}
+
+
+template <typename StaticVisitor>
+bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(Heap* heap,
+                                                      JSFunction* function) {
+  SharedFunctionInfo* shared_info = function->shared();
+
+  // Code is either on stack, in compilation cache or referenced
+  // by optimized version of function.
+  MarkBit code_mark = Marking::MarkBitFrom(function->code());
+  if (code_mark.Get()) {
+    return false;
+  }
+
+  // The function must have a valid context and not be a builtin.
+  if (!IsValidNonBuiltinContext(function->context())) {
+    return false;
+  }
+
+  // We do not (yet) flush code for optimized functions.
+  if (function->code() != shared_info->code()) {
+    return false;
+  }
+
+  // Check age of optimized code.
+  if (FLAG_age_code && !function->code()->IsOld()) {
+    return false;
+  }
+
+  return IsFlushable(heap, shared_info);
+}
+
+
+template <typename StaticVisitor>
+bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
+    Heap* heap, SharedFunctionInfo* shared_info) {
+  // Code is either on stack, in compilation cache or referenced
+  // by optimized version of function.
+  MarkBit code_mark = Marking::MarkBitFrom(shared_info->code());
+  if (code_mark.Get()) {
+    return false;
+  }
+
+  // The function must be compiled and have the source code available,
+  // to be able to recompile it in case we need the function again.
+  if (!(shared_info->is_compiled() && HasSourceCode(heap, shared_info))) {
+    return false;
+  }
+
+  // We never flush code for API functions.
+  Object* function_data = shared_info->function_data();
+  if (function_data->IsFunctionTemplateInfo()) {
+    return false;
+  }
+
+  // Only flush code for functions.
+  if (shared_info->code()->kind() != Code::FUNCTION) {
+    return false;
+  }
+
+  // Function must be lazy compilable.
+  if (!shared_info->allows_lazy_compilation()) {
+    return false;
+  }
+
+  // We do not (yet?) flush code for generator functions, because we don't know
+  // if there are still live activations (generator objects) on the heap.
+  if (shared_info->is_generator()) {
+    return false;
+  }
+
+  // If this is a full script wrapped in a function we do not flush the code.
+  if (shared_info->is_toplevel()) {
+    return false;
+  }
+
+  // If this is a function initialized with %SetCode then the one-to-one
+  // relation between SharedFunctionInfo and Code is broken.
+  if (shared_info->dont_flush()) {
+    return false;
+  }
+
+  // Check age of code. If code aging is disabled we never flush.
+  if (!FLAG_age_code || !shared_info->code()->IsOld()) {
+    return false;
+  }
+
+  return true;
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoStrongCode(
+    Heap* heap, HeapObject* object) {
+  Object** start_slot = HeapObject::RawField(
+      object, SharedFunctionInfo::BodyDescriptor::kStartOffset);
+  Object** end_slot = HeapObject::RawField(
+      object, SharedFunctionInfo::BodyDescriptor::kEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoWeakCode(
+    Heap* heap, HeapObject* object) {
+  Object** name_slot =
+      HeapObject::RawField(object, SharedFunctionInfo::kNameOffset);
+  StaticVisitor::VisitPointer(heap, name_slot);
+
+  // Skip visiting kCodeOffset as it is treated weakly here.
+  STATIC_ASSERT(SharedFunctionInfo::kNameOffset + kPointerSize ==
+                SharedFunctionInfo::kCodeOffset);
+  STATIC_ASSERT(SharedFunctionInfo::kCodeOffset + kPointerSize ==
+                SharedFunctionInfo::kOptimizedCodeMapOffset);
+
+  Object** start_slot =
+      HeapObject::RawField(object, SharedFunctionInfo::kOptimizedCodeMapOffset);
+  Object** end_slot = HeapObject::RawField(
+      object, SharedFunctionInfo::BodyDescriptor::kEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionStrongCode(
+    Heap* heap, HeapObject* object) {
+  Object** start_slot =
+      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
+  Object** end_slot =
+      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+
+  VisitCodeEntry(heap, object->address() + JSFunction::kCodeEntryOffset);
+  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
+                JSFunction::kPrototypeOrInitialMapOffset);
+
+  start_slot =
+      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
+  end_slot = HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+template <typename StaticVisitor>
+void StaticMarkingVisitor<StaticVisitor>::VisitJSFunctionWeakCode(
+    Heap* heap, HeapObject* object) {
+  Object** start_slot =
+      HeapObject::RawField(object, JSFunction::kPropertiesOffset);
+  Object** end_slot =
+      HeapObject::RawField(object, JSFunction::kCodeEntryOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+
+  // Skip visiting kCodeEntryOffset as it is treated weakly here.
+  STATIC_ASSERT(JSFunction::kCodeEntryOffset + kPointerSize ==
+                JSFunction::kPrototypeOrInitialMapOffset);
+
+  start_slot =
+      HeapObject::RawField(object, JSFunction::kPrototypeOrInitialMapOffset);
+  end_slot = HeapObject::RawField(object, JSFunction::kNonWeakFieldsEndOffset);
+  StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+}
+
+
+void Code::CodeIterateBody(ObjectVisitor* v) {
+  int mode_mask = RelocInfo::kCodeTargetMask |
+                  RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
+                  RelocInfo::ModeMask(RelocInfo::CELL) |
+                  RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
+                  RelocInfo::ModeMask(RelocInfo::JS_RETURN) |
+                  RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) |
+                  RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY);
+
+  // There are two places where we iterate code bodies: here and the
+  // templated CodeIterateBody (below). They should be kept in sync.
+  IteratePointer(v, kRelocationInfoOffset);
+  IteratePointer(v, kHandlerTableOffset);
+  IteratePointer(v, kDeoptimizationDataOffset);
+  IteratePointer(v, kTypeFeedbackInfoOffset);
+  IterateNextCodeLink(v, kNextCodeLinkOffset);
+  IteratePointer(v, kConstantPoolOffset);
+
+  RelocIterator it(this, mode_mask);
+  Isolate* isolate = this->GetIsolate();
+  for (; !it.done(); it.next()) {
+    it.rinfo()->Visit(isolate, v);
+  }
+}
+
+
+template <typename StaticVisitor>
+void Code::CodeIterateBody(Heap* heap) {
+  int mode_mask = RelocInfo::kCodeTargetMask |
+                  RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
+                  RelocInfo::ModeMask(RelocInfo::CELL) |
+                  RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE) |
+                  RelocInfo::ModeMask(RelocInfo::JS_RETURN) |
+                  RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) |
+                  RelocInfo::ModeMask(RelocInfo::RUNTIME_ENTRY);
+
+  // There are two places where we iterate code bodies: here and the non-
+  // templated CodeIterateBody (above). They should be kept in sync.
+  StaticVisitor::VisitPointer(
+      heap,
+      reinterpret_cast<Object**>(this->address() + kRelocationInfoOffset));
+  StaticVisitor::VisitPointer(
+      heap, reinterpret_cast<Object**>(this->address() + kHandlerTableOffset));
+  StaticVisitor::VisitPointer(
+      heap,
+      reinterpret_cast<Object**>(this->address() + kDeoptimizationDataOffset));
+  StaticVisitor::VisitPointer(
+      heap,
+      reinterpret_cast<Object**>(this->address() + kTypeFeedbackInfoOffset));
+  StaticVisitor::VisitNextCodeLink(
+      heap, reinterpret_cast<Object**>(this->address() + kNextCodeLinkOffset));
+  StaticVisitor::VisitPointer(
+      heap, reinterpret_cast<Object**>(this->address() + kConstantPoolOffset));
+
+
+  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_