Implement immutable prototype chains

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 4697 matching lines @@
 
 void Map::set_migration_target(bool value) {
   set_bit_field3(IsMigrationTarget::update(bit_field3(), value));
 }
 
 
 bool Map::is_migration_target() {
   return IsMigrationTarget::decode(bit_field3());
 }
 
+void Map::set_immutable_proto(bool value) {
+  set_bit_field3(ImmutablePrototype::update(bit_field3(), value));
+}
+
+bool Map::is_immutable_proto() {
+  return ImmutablePrototype::decode(bit_field3());
+}
 
 void Map::set_new_target_is_base(bool value) {
   set_bit_field3(NewTargetIsBase::update(bit_field3(), value));
 }
 
 
 bool Map::new_target_is_base() { return NewTargetIsBase::decode(bit_field3()); }
 
 
 void Map::set_construction_counter(int value) {
@@ skipping 886 matching lines @@
 ACCESSORS(FunctionTemplateInfo, instance_call_handler, Object,
           kInstanceCallHandlerOffset)
 ACCESSORS(FunctionTemplateInfo, access_check_info, Object,
           kAccessCheckInfoOffset)
 ACCESSORS(FunctionTemplateInfo, shared_function_info, Object,
           kSharedFunctionInfoOffset)
 
 SMI_ACCESSORS(FunctionTemplateInfo, flag, kFlagOffset)
 
 ACCESSORS(ObjectTemplateInfo, constructor, Object, kConstructorOffset)
-ACCESSORS(ObjectTemplateInfo, internal_field_count, Object,
-          kInternalFieldCountOffset)
+ACCESSORS(ObjectTemplateInfo, data, Object, kDataOffset)
+int ObjectTemplateInfo::internal_field_count() const {
+  Object* value = data();
+  DCHECK(value->IsSmi());
+  return Smi::cast(value)->value() >> 1;

[Toon Verwaest, 2016/06/30 15:35:33]

You probably want to use BitField to designate the bits, decode and combine
them. E.g., set_data(Smi::FromInt(InternalFieldCount::update(data->value(),
new_count)));

[Dan Ehrenberg, 2016/06/30 23:12:41]

Done

+}
+void ObjectTemplateInfo::set_internal_field_count(int count) {
+  DCHECK(count << 1 < Smi::kMaxValue);
+  return set_data(Smi::FromInt((immutable_proto() ? 1 : 0) | (count << 1)));
+}
+bool ObjectTemplateInfo::immutable_proto() const {
+  Object* value = data();
+  DCHECK(value->IsSmi());
+  return Smi::cast(value)->value() & 1;
+}
+void ObjectTemplateInfo::set_immutable_proto(bool immutable) {
+  return set_data(
+      Smi::FromInt((immutable ? 1 : 0) | (internal_field_count() << 1)));
+}
 
 ACCESSORS(AllocationSite, transition_info, Object, kTransitionInfoOffset)
 ACCESSORS(AllocationSite, nested_site, Object, kNestedSiteOffset)
 SMI_ACCESSORS(AllocationSite, pretenure_data, kPretenureDataOffset)
 SMI_ACCESSORS(AllocationSite, pretenure_create_count,
               kPretenureCreateCountOffset)
 ACCESSORS(AllocationSite, dependent_code, DependentCode,
           kDependentCodeOffset)
 ACCESSORS(AllocationSite, weak_next, Object, kWeakNextOffset)
 ACCESSORS(AllocationMemento, allocation_site, Object, kAllocationSiteOffset)
@@ skipping 2402 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_