Add infrastructure to keep track of references to prototypes.

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 689 matching lines @@
 TYPE_CHECKER(JSSet, JS_SET_TYPE)
 TYPE_CHECKER(JSMap, JS_MAP_TYPE)
 TYPE_CHECKER(JSSetIterator, JS_SET_ITERATOR_TYPE)
 TYPE_CHECKER(JSMapIterator, JS_MAP_ITERATOR_TYPE)
 TYPE_CHECKER(JSWeakMap, JS_WEAK_MAP_TYPE)
 TYPE_CHECKER(JSWeakSet, JS_WEAK_SET_TYPE)
 TYPE_CHECKER(JSContextExtensionObject, JS_CONTEXT_EXTENSION_OBJECT_TYPE)
 TYPE_CHECKER(Map, MAP_TYPE)
 TYPE_CHECKER(FixedArray, FIXED_ARRAY_TYPE)
 TYPE_CHECKER(FixedDoubleArray, FIXED_DOUBLE_ARRAY_TYPE)
+TYPE_CHECKER(WeakFixedArray, FIXED_ARRAY_TYPE)
 TYPE_CHECKER(ConstantPoolArray, CONSTANT_POOL_ARRAY_TYPE)
 
 
 bool Object::IsJSWeakCollection() const {
   return IsJSWeakMap() || IsJSWeakSet();
 }
 
 
 bool Object::IsDescriptorArray() const {
   return IsFixedArray();
@@ skipping 1641 matching lines @@
 }
 
 
 void FixedDoubleArray::FillWithHoles(int from, int to) {
   for (int i = from; i < to; i++) {
     set_the_hole(i);
   }
 }
 
 
+Object* WeakFixedArray::Get(int index) const {
+  Object* raw = FixedArray::cast(this)->get(index + kFirstIndex);
+  if (raw->IsSmi()) return raw;
+  return WeakCell::cast(raw)->value();
+}
+
+
+bool WeakFixedArray::IsEmptySlot(int index) const {
+  DCHECK(index < Length());
+  return Get(index)->IsSmi();
+}
+
+
+void WeakFixedArray::clear(int index) {
+  FixedArray::cast(this)->set(index + kFirstIndex, Smi::FromInt(0));
+}
+
+
+int WeakFixedArray::Length() const {
+  return FixedArray::cast(this)->length() - kFirstIndex;
+}
+
+
+int WeakFixedArray::last_used_index() const {
+  return Smi::cast(FixedArray::cast(this)->get(kLastUsedIndexIndex))->value();
+}
+
+
+void WeakFixedArray::set_last_used_index(int index) {
+  FixedArray::cast(this)->set(kLastUsedIndexIndex, Smi::FromInt(index));
+}
+
+
 void ConstantPoolArray::NumberOfEntries::increment(Type type) {
   DCHECK(type < NUMBER_OF_TYPES);
   element_counts_[type]++;
 }
 
 
 int ConstantPoolArray::NumberOfEntries::equals(
     const ConstantPoolArray::NumberOfEntries& other) const {
   for (int i = 0; i < NUMBER_OF_TYPES; i++) {
     if (element_counts_[i] != other.element_counts_[i]) return false;
@@ skipping 976 matching lines @@
 CAST_ACCESSOR(SeqTwoByteString)
 CAST_ACCESSOR(SharedFunctionInfo)
 CAST_ACCESSOR(SlicedString)
 CAST_ACCESSOR(Smi)
 CAST_ACCESSOR(String)
 CAST_ACCESSOR(StringTable)
 CAST_ACCESSOR(Struct)
 CAST_ACCESSOR(Symbol)
 CAST_ACCESSOR(UnseededNumberDictionary)
 CAST_ACCESSOR(WeakCell)
+CAST_ACCESSOR(WeakFixedArray)
 CAST_ACCESSOR(WeakHashTable)
 
 
 template <class Traits>
 FixedTypedArray<Traits>* FixedTypedArray<Traits>::cast(Object* object) {
   SLOW_DCHECK(object->IsHeapObject() &&
               HeapObject::cast(object)->map()->instance_type() ==
               Traits::kInstanceType);
   return reinterpret_cast<FixedTypedArray<Traits>*>(object);
 }
@@ skipping 4141 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_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_