[objects] do not visit ArrayBuffer's backing store

src/objects-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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 6568 matching lines @@
 
 
 bool JSArrayBuffer::is_shared() { return IsShared::decode(bit_field()); }
 
 
 void JSArrayBuffer::set_is_shared(bool value) {
   set_bit_field(IsShared::update(bit_field(), value));
 }
 
 
+// static
+template <typename StaticVisitor>
+void JSArrayBuffer::BodyDescriptor::IterateBody(Heap* heap, HeapObject* obj) {
+  StaticVisitor::VisitPointers(
+      heap, obj,
+      HeapObject::RawField(obj, JSArrayBuffer::BodyDescriptor::kStartOffset),

[jochen (gone - plz use gerrit), 2015/09/14 10:04:36]

I wouldn't use constants here, just visit the length and the internal fields

[fedor.indutny, 2015/09/14 17:08:16]

Acknowledged.

+      HeapObject::RawField(obj, JSArrayBuffer::kBackingStoreOffset));
+  StaticVisitor::VisitPointers(
+      heap, obj, HeapObject::RawField(
+                     obj, JSArrayBuffer::kBackingStoreOffset + kPointerSize),
+      HeapObject::RawField(obj, JSArrayBuffer::kSizeWithInternalFields));
+}
+
+
+void JSArrayBuffer::BodyDescriptor::IterateBody(HeapObject* obj,
+                                                ObjectVisitor* v) {
+  v->VisitPointers(
+      HeapObject::RawField(obj, JSArrayBuffer::BodyDescriptor::kStartOffset),
+      HeapObject::RawField(obj, JSArrayBuffer::kBackingStoreOffset));
+  v->VisitPointers(
+      HeapObject::RawField(obj,
+                           JSArrayBuffer::kBackingStoreOffset + kPointerSize),
+      HeapObject::RawField(obj, JSArrayBuffer::kSizeWithInternalFields));
+}
+
+
 Object* JSArrayBufferView::byte_offset() const {
   if (WasNeutered()) return Smi::FromInt(0);
   return Object::cast(READ_FIELD(this, kByteOffsetOffset));
 }
 
 
 void JSArrayBufferView::set_byte_offset(Object* value, WriteBarrierMode mode) {
   WRITE_FIELD(this, kByteOffsetOffset, value);
   CONDITIONAL_WRITE_BARRIER(GetHeap(), this, kByteOffsetOffset, value, mode);
 }
@@ skipping 1306 matching lines @@
 #undef READ_INT64_FIELD
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_