| // Copyright 2014 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. |
| |
| #include "src/v8.h" |
| |
| #include "src/bootstrapper.h" |
| #include "src/deoptimizer.h" |
| #include "src/lookup.h" |
| #include "src/lookup-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| void LookupIterator::Next() { |
| DCHECK_NE(JSPROXY, state_); |
| DCHECK_NE(TRANSITION, state_); |
| DisallowHeapAllocation no_gc; |
| has_property_ = false; |
| |
| JSReceiver* holder = |
| maybe_holder_.is_null() ? NULL : *maybe_holder_.ToHandleChecked(); |
| Map* map = *holder_map_; |
| |
| // Perform lookup on current holder. |
| state_ = LookupInHolder(map, holder); |
| if (IsFound()) return; |
| |
| // Continue lookup if lookup on current holder failed. |
| do { |
| JSReceiver* maybe_holder = NextHolder(map); |
| if (maybe_holder == NULL) break; |
| holder = maybe_holder; |
| map = holder->map(); |
| state_ = LookupInHolder(map, holder); |
| } while (!IsFound()); |
| |
| if (holder == NULL) return; |
| |
| maybe_holder_ = handle(holder, isolate_); |
| holder_map_ = handle(map, isolate_); |
| } |
| |
| |
| Handle<JSReceiver> LookupIterator::GetRoot() const { |
| Handle<Object> receiver = GetReceiver(); |
| if (receiver->IsJSReceiver()) return Handle<JSReceiver>::cast(receiver); |
| Handle<Object> root = |
| handle(receiver->GetRootMap(isolate_)->prototype(), isolate_); |
| CHECK(!root->IsNull()); |
| return Handle<JSReceiver>::cast(root); |
| } |
| |
| |
| Handle<Map> LookupIterator::GetReceiverMap() const { |
| Handle<Object> receiver = GetReceiver(); |
| if (receiver->IsNumber()) return isolate_->factory()->heap_number_map(); |
| return handle(Handle<HeapObject>::cast(receiver)->map(), isolate_); |
| } |
| |
| |
| Handle<JSObject> LookupIterator::GetStoreTarget() const { |
| Handle<JSObject> receiver = Handle<JSObject>::cast(GetReceiver()); |
| |
| if (receiver->IsJSGlobalProxy()) { |
| PrototypeIterator iter(isolate(), receiver); |
| if (iter.IsAtEnd()) return receiver; |
| return Handle<JSGlobalObject>::cast(PrototypeIterator::GetCurrent(iter)); |
| } |
| return receiver; |
| } |
| |
| |
| bool LookupIterator::IsBootstrapping() const { |
| return isolate_->bootstrapper()->IsActive(); |
| } |
| |
| |
| bool LookupIterator::HasAccess(v8::AccessType access_type) const { |
| DCHECK_EQ(ACCESS_CHECK, state_); |
| DCHECK(is_guaranteed_to_have_holder()); |
| return isolate_->MayNamedAccess(GetHolder<JSObject>(), name_, access_type); |
| } |
| |
| |
| void LookupIterator::ReloadPropertyInformation() { |
| state_ = BEFORE_PROPERTY; |
| state_ = LookupInHolder(*holder_map_, *maybe_holder_.ToHandleChecked()); |
| DCHECK(IsFound() || holder_map_->is_dictionary_map()); |
| } |
| |
| |
| void LookupIterator::PrepareForDataProperty(Handle<Object> value) { |
| DCHECK(state_ == DATA || state_ == ACCESSOR); |
| DCHECK(HolderIsReceiverOrHiddenPrototype()); |
| if (holder_map_->is_dictionary_map()) return; |
| holder_map_ = |
| Map::PrepareForDataProperty(holder_map_, descriptor_number(), value); |
| JSObject::MigrateToMap(GetHolder<JSObject>(), holder_map_); |
| ReloadPropertyInformation(); |
| } |
| |
| |
| void LookupIterator::ReconfigureDataProperty(Handle<Object> value, |
| PropertyAttributes attributes) { |
| DCHECK(state_ == DATA || state_ == ACCESSOR); |
| DCHECK(HolderIsReceiverOrHiddenPrototype()); |
| Handle<JSObject> holder = GetHolder<JSObject>(); |
| if (holder_map_->is_dictionary_map()) { |
| PropertyDetails details(attributes, NORMAL, 0); |
| JSObject::SetNormalizedProperty(holder, name(), value, details); |
| } else { |
| holder_map_ = Map::ReconfigureDataProperty(holder_map_, descriptor_number(), |
| attributes); |
| JSObject::MigrateToMap(holder, holder_map_); |
| } |
| |
| ReloadPropertyInformation(); |
| } |
| |
| |
| void LookupIterator::PrepareTransitionToDataProperty( |
| Handle<Object> value, PropertyAttributes attributes, |
| Object::StoreFromKeyed store_mode) { |
| if (state_ == TRANSITION) return; |
| DCHECK(state_ != LookupIterator::ACCESSOR || |
| GetAccessors()->IsDeclaredAccessorInfo()); |
| DCHECK(state_ == NOT_FOUND || !HolderIsReceiverOrHiddenPrototype()); |
| |
| // Can only be called when the receiver is a JSObject. JSProxy has to be |
| // handled via a trap. Adding properties to primitive values is not |
| // observable. |
| Handle<JSObject> receiver = GetStoreTarget(); |
| |
| if (!name().is_identical_to(isolate()->factory()->hidden_string()) && |
| !receiver->map()->is_extensible()) { |
| return; |
| } |
| |
| transition_map_ = Map::TransitionToDataProperty( |
| handle(receiver->map(), isolate_), name_, value, attributes, store_mode); |
| state_ = TRANSITION; |
| } |
| |
| |
| void LookupIterator::ApplyTransitionToDataProperty() { |
| DCHECK_EQ(TRANSITION, state_); |
| |
| Handle<JSObject> receiver = GetStoreTarget(); |
| maybe_holder_ = receiver; |
| holder_map_ = transition_map_; |
| JSObject::MigrateToMap(receiver, holder_map_); |
| ReloadPropertyInformation(); |
| } |
| |
| |
| void LookupIterator::TransitionToAccessorProperty( |
| AccessorComponent component, Handle<Object> accessor, |
| PropertyAttributes attributes) { |
| DCHECK(!accessor->IsNull()); |
| // Can only be called when the receiver is a JSObject. JSProxy has to be |
| // handled via a trap. Adding properties to primitive values is not |
| // observable. |
| Handle<JSObject> receiver = GetStoreTarget(); |
| maybe_holder_ = receiver; |
| holder_map_ = |
| Map::TransitionToAccessorProperty(handle(receiver->map(), isolate_), |
| name_, component, accessor, attributes); |
| JSObject::MigrateToMap(receiver, holder_map_); |
| |
| ReloadPropertyInformation(); |
| |
| if (!holder_map_->is_dictionary_map()) return; |
| |
| // We have to deoptimize since accesses to data properties may have been |
| // inlined without a corresponding map-check. |
| if (holder_map_->IsGlobalObjectMap()) { |
| Deoptimizer::DeoptimizeGlobalObject(*receiver); |
| } |
| |
| // Install the accessor into the dictionary-mode object. |
| PropertyDetails details(attributes, CALLBACKS, 0); |
| Handle<AccessorPair> pair; |
| if (state() == ACCESSOR && GetAccessors()->IsAccessorPair()) { |
| pair = Handle<AccessorPair>::cast(GetAccessors()); |
| // If the component and attributes are identical, nothing has to be done. |
| if (pair->get(component) == *accessor) { |
| if (property_details().attributes() == attributes) return; |
| } else { |
| pair = AccessorPair::Copy(pair); |
| pair->set(component, *accessor); |
| } |
| } else { |
| pair = isolate()->factory()->NewAccessorPair(); |
| pair->set(component, *accessor); |
| } |
| JSObject::SetNormalizedProperty(receiver, name_, pair, details); |
| |
| JSObject::ReoptimizeIfPrototype(receiver); |
| holder_map_ = handle(receiver->map(), isolate_); |
| ReloadPropertyInformation(); |
| } |
| |
| |
| bool LookupIterator::HolderIsReceiverOrHiddenPrototype() const { |
| DCHECK(has_property_ || state_ == INTERCEPTOR || state_ == JSPROXY); |
| // Optimization that only works if configuration_ is not mutable. |
| if (!check_prototype_chain()) return true; |
| DisallowHeapAllocation no_gc; |
| Handle<Object> receiver = GetReceiver(); |
| if (!receiver->IsJSReceiver()) return false; |
| Object* current = *receiver; |
| JSReceiver* holder = *maybe_holder_.ToHandleChecked(); |
| // JSProxy do not occur as hidden prototypes. |
| if (current->IsJSProxy()) { |
| return JSReceiver::cast(current) == holder; |
| } |
| PrototypeIterator iter(isolate(), current, |
| PrototypeIterator::START_AT_RECEIVER); |
| do { |
| if (JSReceiver::cast(iter.GetCurrent()) == holder) return true; |
| DCHECK(!current->IsJSProxy()); |
| iter.Advance(); |
| } while (!iter.IsAtEnd(PrototypeIterator::END_AT_NON_HIDDEN)); |
| return false; |
| } |
| |
| |
| Handle<Object> LookupIterator::FetchValue() const { |
| Object* result = NULL; |
| Handle<JSObject> holder = GetHolder<JSObject>(); |
| if (holder_map_->is_dictionary_map()) { |
| result = holder->property_dictionary()->ValueAt(number_); |
| if (holder_map_->IsGlobalObjectMap()) { |
| result = PropertyCell::cast(result)->value(); |
| } |
| } else if (property_details_.type() == v8::internal::FIELD) { |
| FieldIndex field_index = FieldIndex::ForDescriptor(*holder_map_, number_); |
| return JSObject::FastPropertyAt(holder, property_details_.representation(), |
| field_index); |
| } else { |
| result = holder_map_->instance_descriptors()->GetValue(number_); |
| } |
| return handle(result, isolate_); |
| } |
| |
| |
| int LookupIterator::GetConstantIndex() const { |
| DCHECK(has_property_); |
| DCHECK(!holder_map_->is_dictionary_map()); |
| DCHECK_EQ(v8::internal::CONSTANT, property_details_.type()); |
| return descriptor_number(); |
| } |
| |
| |
| FieldIndex LookupIterator::GetFieldIndex() const { |
| DCHECK(has_property_); |
| DCHECK(!holder_map_->is_dictionary_map()); |
| DCHECK_EQ(v8::internal::FIELD, property_details_.type()); |
| int index = |
| holder_map_->instance_descriptors()->GetFieldIndex(descriptor_number()); |
| bool is_double = representation().IsDouble(); |
| return FieldIndex::ForPropertyIndex(*holder_map_, index, is_double); |
| } |
| |
| |
| Handle<HeapType> LookupIterator::GetFieldType() const { |
| DCHECK(has_property_); |
| DCHECK(!holder_map_->is_dictionary_map()); |
| DCHECK_EQ(v8::internal::FIELD, property_details_.type()); |
| return handle( |
| holder_map_->instance_descriptors()->GetFieldType(descriptor_number()), |
| isolate_); |
| } |
| |
| |
| Handle<PropertyCell> LookupIterator::GetPropertyCell() const { |
| Handle<JSObject> holder = GetHolder<JSObject>(); |
| Handle<GlobalObject> global = Handle<GlobalObject>::cast(holder); |
| Object* value = global->property_dictionary()->ValueAt(dictionary_entry()); |
| return Handle<PropertyCell>(PropertyCell::cast(value)); |
| } |
| |
| |
| Handle<Object> LookupIterator::GetAccessors() const { |
| DCHECK_EQ(ACCESSOR, state_); |
| return FetchValue(); |
| } |
| |
| |
| Handle<Object> LookupIterator::GetDataValue() const { |
| DCHECK_EQ(DATA, state_); |
| Handle<Object> value = FetchValue(); |
| return value; |
| } |
| |
| |
| void LookupIterator::WriteDataValue(Handle<Object> value) { |
| DCHECK(is_guaranteed_to_have_holder()); |
| DCHECK_EQ(DATA, state_); |
| Handle<JSObject> holder = GetHolder<JSObject>(); |
| if (holder_map_->is_dictionary_map()) { |
| NameDictionary* property_dictionary = holder->property_dictionary(); |
| if (holder->IsGlobalObject()) { |
| Handle<PropertyCell> cell( |
| PropertyCell::cast(property_dictionary->ValueAt(dictionary_entry()))); |
| PropertyCell::SetValueInferType(cell, value); |
| } else { |
| property_dictionary->ValueAtPut(dictionary_entry(), *value); |
| } |
| } else if (property_details_.type() == v8::internal::FIELD) { |
| holder->WriteToField(descriptor_number(), *value); |
| } else { |
| DCHECK_EQ(v8::internal::CONSTANT, property_details_.type()); |
| } |
| } |
| |
| |
| void LookupIterator::InternalizeName() { |
| if (name_->IsUniqueName()) return; |
| name_ = factory()->InternalizeString(Handle<String>::cast(name_)); |
| } |
| } } // namespace v8::internal |