| // Copyright 2017 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_MAP_INL_H_ |
| #define V8_OBJECTS_MAP_INL_H_ |
| |
| #include "src/objects/map.h" |
| |
| #include "src/field-type.h" |
| #include "src/heap/heap-write-barrier-inl.h" |
| #include "src/layout-descriptor-inl.h" |
| #include "src/objects-inl.h" |
| #include "src/objects/api-callbacks-inl.h" |
| #include "src/objects/cell-inl.h" |
| #include "src/objects/descriptor-array-inl.h" |
| #include "src/objects/instance-type-inl.h" |
| #include "src/objects/prototype-info-inl.h" |
| #include "src/objects/shared-function-info.h" |
| #include "src/objects/templates-inl.h" |
| #include "src/property.h" |
| #include "src/transitions-inl.h" |
| |
| // Has to be the last include (doesn't have include guards): |
| #include "src/objects/object-macros.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| OBJECT_CONSTRUCTORS_IMPL(Map, HeapObject) |
| CAST_ACCESSOR(Map) |
| |
| DescriptorArray Map::instance_descriptors() const { |
| return DescriptorArray::cast(READ_FIELD(*this, kDescriptorsOffset)); |
| } |
| |
| DescriptorArray Map::synchronized_instance_descriptors() const { |
| return DescriptorArray::cast(ACQUIRE_READ_FIELD(*this, kDescriptorsOffset)); |
| } |
| |
| void Map::set_synchronized_instance_descriptors(DescriptorArray value, |
| WriteBarrierMode mode) { |
| RELEASE_WRITE_FIELD(*this, kDescriptorsOffset, value); |
| CONDITIONAL_WRITE_BARRIER(*this, kDescriptorsOffset, value, mode); |
| } |
| |
| // A freshly allocated layout descriptor can be set on an existing map. |
| // We need to use release-store and acquire-load accessor pairs to ensure |
| // that the concurrent marking thread observes initializing stores of the |
| // layout descriptor. |
| SYNCHRONIZED_ACCESSORS_CHECKED(Map, layout_descriptor, LayoutDescriptor, |
| kLayoutDescriptorOffset, |
| FLAG_unbox_double_fields) |
| WEAK_ACCESSORS(Map, raw_transitions, kTransitionsOrPrototypeInfoOffset) |
| |
| // |bit_field| fields. |
| // Concurrent access to |has_prototype_slot| and |has_non_instance_prototype| |
| // is explicitly whitelisted here. The former is never modified after the map |
| // is setup but it's being read by concurrent marker when pointer compression |
| // is enabled. The latter bit can be modified on a live objects. |
| BIT_FIELD_ACCESSORS(Map, relaxed_bit_field, has_non_instance_prototype, |
| Map::HasNonInstancePrototypeBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, is_callable, Map::IsCallableBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, has_named_interceptor, |
| Map::HasNamedInterceptorBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, has_indexed_interceptor, |
| Map::HasIndexedInterceptorBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, is_undetectable, Map::IsUndetectableBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, is_access_check_needed, |
| Map::IsAccessCheckNeededBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field, is_constructor, Map::IsConstructorBit) |
| BIT_FIELD_ACCESSORS(Map, relaxed_bit_field, has_prototype_slot, |
| Map::HasPrototypeSlotBit) |
| |
| // |bit_field2| fields. |
| BIT_FIELD_ACCESSORS(Map, bit_field2, is_extensible, Map::IsExtensibleBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field2, is_prototype_map, Map::IsPrototypeMapBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field2, is_in_retained_map_list, |
| Map::IsInRetainedMapListBit) |
| |
| // |bit_field3| fields. |
| BIT_FIELD_ACCESSORS(Map, bit_field3, owns_descriptors, Map::OwnsDescriptorsBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, has_hidden_prototype, |
| Map::HasHiddenPrototypeBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, is_deprecated, Map::IsDeprecatedBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, is_migration_target, |
| Map::IsMigrationTargetBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, is_immutable_proto, |
| Map::IsImmutablePrototypeBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, new_target_is_base, |
| Map::NewTargetIsBaseBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, may_have_interesting_symbols, |
| Map::MayHaveInterestingSymbolsBit) |
| BIT_FIELD_ACCESSORS(Map, bit_field3, construction_counter, |
| Map::ConstructionCounterBits) |
| |
| InterceptorInfo Map::GetNamedInterceptor() { |
| DCHECK(has_named_interceptor()); |
| FunctionTemplateInfo info = GetFunctionTemplateInfo(); |
| return InterceptorInfo::cast(info->GetNamedPropertyHandler()); |
| } |
| |
| InterceptorInfo Map::GetIndexedInterceptor() { |
| DCHECK(has_indexed_interceptor()); |
| FunctionTemplateInfo info = GetFunctionTemplateInfo(); |
| return InterceptorInfo::cast(info->GetIndexedPropertyHandler()); |
| } |
| |
| bool Map::IsMostGeneralFieldType(Representation representation, |
| FieldType field_type) { |
| return !representation.IsHeapObject() || field_type->IsAny(); |
| } |
| |
| bool Map::CanHaveFastTransitionableElementsKind(InstanceType instance_type) { |
| return instance_type == JS_ARRAY_TYPE || instance_type == JS_VALUE_TYPE || |
| instance_type == JS_ARGUMENTS_TYPE; |
| } |
| |
| bool Map::CanHaveFastTransitionableElementsKind() const { |
| return CanHaveFastTransitionableElementsKind(instance_type()); |
| } |
| |
| // static |
| void Map::GeneralizeIfCanHaveTransitionableFastElementsKind( |
| Isolate* isolate, InstanceType instance_type, |
| Representation* representation, Handle<FieldType>* field_type) { |
| if (CanHaveFastTransitionableElementsKind(instance_type)) { |
| // We don't support propagation of field generalization through elements |
| // kind transitions because they are inserted into the transition tree |
| // before field transitions. In order to avoid complexity of handling |
| // such a case we ensure that all maps with transitionable elements kinds |
| // have the most general field representation and type. |
| *field_type = FieldType::Any(isolate); |
| *representation = Representation::Tagged(); |
| } |
| } |
| |
| bool Map::IsUnboxedDoubleField(FieldIndex index) const { |
| if (!FLAG_unbox_double_fields) return false; |
| if (index.is_hidden_field() || !index.is_inobject()) return false; |
| return !layout_descriptor()->IsTagged(index.property_index()); |
| } |
| |
| bool Map::TooManyFastProperties(StoreOrigin store_origin) const { |
| if (UnusedPropertyFields() != 0) return false; |
| if (is_prototype_map()) return false; |
| if (store_origin == StoreOrigin::kNamed) { |
| int limit = Max(kMaxFastProperties, GetInObjectProperties()); |
| FieldCounts counts = GetFieldCounts(); |
| // Only count mutable fields so that objects with large numbers of |
| // constant functions do not go to dictionary mode. That would be bad |
| // because such objects have often been used as modules. |
| int external = counts.mutable_count() - GetInObjectProperties(); |
| return external > limit || counts.GetTotal() > kMaxNumberOfDescriptors; |
| } else { |
| int limit = Max(kFastPropertiesSoftLimit, GetInObjectProperties()); |
| int external = NumberOfFields() - GetInObjectProperties(); |
| return external > limit; |
| } |
| } |
| |
| PropertyDetails Map::GetLastDescriptorDetails() const { |
| return instance_descriptors()->GetDetails(LastAdded()); |
| } |
| |
| int Map::LastAdded() const { |
| int number_of_own_descriptors = NumberOfOwnDescriptors(); |
| DCHECK_GT(number_of_own_descriptors, 0); |
| return number_of_own_descriptors - 1; |
| } |
| |
| int Map::NumberOfOwnDescriptors() const { |
| return NumberOfOwnDescriptorsBits::decode(bit_field3()); |
| } |
| |
| void Map::SetNumberOfOwnDescriptors(int number) { |
| DCHECK_LE(number, instance_descriptors()->number_of_descriptors()); |
| CHECK_LE(static_cast<unsigned>(number), |
| static_cast<unsigned>(kMaxNumberOfDescriptors)); |
| set_bit_field3(NumberOfOwnDescriptorsBits::update(bit_field3(), number)); |
| } |
| |
| int Map::EnumLength() const { return EnumLengthBits::decode(bit_field3()); } |
| |
| void Map::SetEnumLength(int length) { |
| if (length != kInvalidEnumCacheSentinel) { |
| DCHECK_LE(length, NumberOfOwnDescriptors()); |
| CHECK_LE(static_cast<unsigned>(length), |
| static_cast<unsigned>(kMaxNumberOfDescriptors)); |
| } |
| set_bit_field3(EnumLengthBits::update(bit_field3(), length)); |
| } |
| |
| FixedArrayBase Map::GetInitialElements() const { |
| FixedArrayBase result; |
| if (has_fast_elements() || has_fast_string_wrapper_elements()) { |
| result = GetReadOnlyRoots().empty_fixed_array(); |
| } else if (has_fast_sloppy_arguments_elements()) { |
| result = GetReadOnlyRoots().empty_sloppy_arguments_elements(); |
| } else if (has_fixed_typed_array_elements()) { |
| result = |
| GetReadOnlyRoots().EmptyFixedTypedArrayForTypedArray(elements_kind()); |
| } else if (has_dictionary_elements()) { |
| result = GetReadOnlyRoots().empty_slow_element_dictionary(); |
| } else { |
| UNREACHABLE(); |
| } |
| DCHECK(!ObjectInYoungGeneration(result)); |
| return result; |
| } |
| |
| VisitorId Map::visitor_id() const { |
| return static_cast<VisitorId>( |
| RELAXED_READ_BYTE_FIELD(*this, kVisitorIdOffset)); |
| } |
| |
| void Map::set_visitor_id(VisitorId id) { |
| CHECK_LT(static_cast<unsigned>(id), 256); |
| RELAXED_WRITE_BYTE_FIELD(*this, kVisitorIdOffset, static_cast<byte>(id)); |
| } |
| |
| int Map::instance_size_in_words() const { |
| return RELAXED_READ_BYTE_FIELD(*this, kInstanceSizeInWordsOffset); |
| } |
| |
| void Map::set_instance_size_in_words(int value) { |
| RELAXED_WRITE_BYTE_FIELD(*this, kInstanceSizeInWordsOffset, |
| static_cast<byte>(value)); |
| } |
| |
| int Map::instance_size() const { |
| return instance_size_in_words() << kTaggedSizeLog2; |
| } |
| |
| void Map::set_instance_size(int value) { |
| CHECK(IsAligned(value, kTaggedSize)); |
| value >>= kTaggedSizeLog2; |
| CHECK_LT(static_cast<unsigned>(value), 256); |
| set_instance_size_in_words(value); |
| } |
| |
| int Map::inobject_properties_start_or_constructor_function_index() const { |
| return RELAXED_READ_BYTE_FIELD( |
| *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset); |
| } |
| |
| void Map::set_inobject_properties_start_or_constructor_function_index( |
| int value) { |
| CHECK_LT(static_cast<unsigned>(value), 256); |
| RELAXED_WRITE_BYTE_FIELD( |
| *this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset, |
| static_cast<byte>(value)); |
| } |
| |
| int Map::GetInObjectPropertiesStartInWords() const { |
| DCHECK(IsJSObjectMap()); |
| return inobject_properties_start_or_constructor_function_index(); |
| } |
| |
| void Map::SetInObjectPropertiesStartInWords(int value) { |
| CHECK(IsJSObjectMap()); |
| set_inobject_properties_start_or_constructor_function_index(value); |
| } |
| |
| int Map::GetInObjectProperties() const { |
| DCHECK(IsJSObjectMap()); |
| return instance_size_in_words() - GetInObjectPropertiesStartInWords(); |
| } |
| |
| int Map::GetConstructorFunctionIndex() const { |
| DCHECK(IsPrimitiveMap()); |
| return inobject_properties_start_or_constructor_function_index(); |
| } |
| |
| void Map::SetConstructorFunctionIndex(int value) { |
| CHECK(IsPrimitiveMap()); |
| set_inobject_properties_start_or_constructor_function_index(value); |
| } |
| |
| int Map::GetInObjectPropertyOffset(int index) const { |
| return (GetInObjectPropertiesStartInWords() + index) * kTaggedSize; |
| } |
| |
| Handle<Map> Map::AddMissingTransitionsForTesting( |
| Isolate* isolate, Handle<Map> split_map, |
| Handle<DescriptorArray> descriptors, |
| Handle<LayoutDescriptor> full_layout_descriptor) { |
| return AddMissingTransitions(isolate, split_map, descriptors, |
| full_layout_descriptor); |
| } |
| |
| InstanceType Map::instance_type() const { |
| return static_cast<InstanceType>( |
| READ_UINT16_FIELD(*this, kInstanceTypeOffset)); |
| } |
| |
| void Map::set_instance_type(InstanceType value) { |
| WRITE_UINT16_FIELD(*this, kInstanceTypeOffset, value); |
| } |
| |
| int Map::UnusedPropertyFields() const { |
| int value = used_or_unused_instance_size_in_words(); |
| DCHECK_IMPLIES(!IsJSObjectMap(), value == 0); |
| int unused; |
| if (value >= JSObject::kFieldsAdded) { |
| unused = instance_size_in_words() - value; |
| } else { |
| // For out of object properties "used_or_unused_instance_size_in_words" |
| // byte encodes the slack in the property array. |
| unused = value; |
| } |
| return unused; |
| } |
| |
| int Map::UnusedInObjectProperties() const { |
| // Like Map::UnusedPropertyFields(), but returns 0 for out of object |
| // properties. |
| int value = used_or_unused_instance_size_in_words(); |
| DCHECK_IMPLIES(!IsJSObjectMap(), value == 0); |
| if (value >= JSObject::kFieldsAdded) { |
| return instance_size_in_words() - value; |
| } |
| return 0; |
| } |
| |
| int Map::used_or_unused_instance_size_in_words() const { |
| return RELAXED_READ_BYTE_FIELD(*this, kUsedOrUnusedInstanceSizeInWordsOffset); |
| } |
| |
| void Map::set_used_or_unused_instance_size_in_words(int value) { |
| CHECK_LE(static_cast<unsigned>(value), 255); |
| RELAXED_WRITE_BYTE_FIELD(*this, kUsedOrUnusedInstanceSizeInWordsOffset, |
| static_cast<byte>(value)); |
| } |
| |
| int Map::UsedInstanceSize() const { |
| int words = used_or_unused_instance_size_in_words(); |
| if (words < JSObject::kFieldsAdded) { |
| // All in-object properties are used and the words is tracking the slack |
| // in the property array. |
| return instance_size(); |
| } |
| return words * kTaggedSize; |
| } |
| |
| void Map::SetInObjectUnusedPropertyFields(int value) { |
| STATIC_ASSERT(JSObject::kFieldsAdded == JSObject::kHeaderSize / kTaggedSize); |
| if (!IsJSObjectMap()) { |
| CHECK_EQ(0, value); |
| set_used_or_unused_instance_size_in_words(0); |
| DCHECK_EQ(0, UnusedPropertyFields()); |
| return; |
| } |
| CHECK_LE(0, value); |
| DCHECK_LE(value, GetInObjectProperties()); |
| int used_inobject_properties = GetInObjectProperties() - value; |
| set_used_or_unused_instance_size_in_words( |
| GetInObjectPropertyOffset(used_inobject_properties) / kTaggedSize); |
| DCHECK_EQ(value, UnusedPropertyFields()); |
| } |
| |
| void Map::SetOutOfObjectUnusedPropertyFields(int value) { |
| STATIC_ASSERT(JSObject::kFieldsAdded == JSObject::kHeaderSize / kTaggedSize); |
| CHECK_LT(static_cast<unsigned>(value), JSObject::kFieldsAdded); |
| // For out of object properties "used_instance_size_in_words" byte encodes |
| // the slack in the property array. |
| set_used_or_unused_instance_size_in_words(value); |
| DCHECK_EQ(value, UnusedPropertyFields()); |
| } |
| |
| void Map::CopyUnusedPropertyFields(Map map) { |
| set_used_or_unused_instance_size_in_words( |
| map->used_or_unused_instance_size_in_words()); |
| DCHECK_EQ(UnusedPropertyFields(), map->UnusedPropertyFields()); |
| } |
| |
| void Map::CopyUnusedPropertyFieldsAdjustedForInstanceSize(Map map) { |
| int value = map->used_or_unused_instance_size_in_words(); |
| if (value >= JSValue::kFieldsAdded) { |
| // Unused in-object fields. Adjust the offset from the object’s start |
| // so it matches the distance to the object’s end. |
| value += instance_size_in_words() - map->instance_size_in_words(); |
| } |
| set_used_or_unused_instance_size_in_words(value); |
| DCHECK_EQ(UnusedPropertyFields(), map->UnusedPropertyFields()); |
| } |
| |
| void Map::AccountAddedPropertyField() { |
| // Update used instance size and unused property fields number. |
| STATIC_ASSERT(JSObject::kFieldsAdded == JSObject::kHeaderSize / kTaggedSize); |
| #ifdef DEBUG |
| int new_unused = UnusedPropertyFields() - 1; |
| if (new_unused < 0) new_unused += JSObject::kFieldsAdded; |
| #endif |
| int value = used_or_unused_instance_size_in_words(); |
| if (value >= JSObject::kFieldsAdded) { |
| if (value == instance_size_in_words()) { |
| AccountAddedOutOfObjectPropertyField(0); |
| } else { |
| // The property is added in-object, so simply increment the counter. |
| set_used_or_unused_instance_size_in_words(value + 1); |
| } |
| } else { |
| AccountAddedOutOfObjectPropertyField(value); |
| } |
| DCHECK_EQ(new_unused, UnusedPropertyFields()); |
| } |
| |
| void Map::AccountAddedOutOfObjectPropertyField(int unused_in_property_array) { |
| unused_in_property_array--; |
| if (unused_in_property_array < 0) { |
| unused_in_property_array += JSObject::kFieldsAdded; |
| } |
| CHECK_LT(static_cast<unsigned>(unused_in_property_array), |
| JSObject::kFieldsAdded); |
| set_used_or_unused_instance_size_in_words(unused_in_property_array); |
| DCHECK_EQ(unused_in_property_array, UnusedPropertyFields()); |
| } |
| |
| byte Map::bit_field() const { return READ_BYTE_FIELD(*this, kBitFieldOffset); } |
| |
| void Map::set_bit_field(byte value) { |
| WRITE_BYTE_FIELD(*this, kBitFieldOffset, value); |
| } |
| |
| byte Map::relaxed_bit_field() const { |
| return RELAXED_READ_BYTE_FIELD(*this, kBitFieldOffset); |
| } |
| |
| void Map::set_relaxed_bit_field(byte value) { |
| RELAXED_WRITE_BYTE_FIELD(*this, kBitFieldOffset, value); |
| } |
| |
| byte Map::bit_field2() const { |
| return READ_BYTE_FIELD(*this, kBitField2Offset); |
| } |
| |
| void Map::set_bit_field2(byte value) { |
| WRITE_BYTE_FIELD(*this, kBitField2Offset, value); |
| } |
| |
| bool Map::is_abandoned_prototype_map() const { |
| return is_prototype_map() && !owns_descriptors(); |
| } |
| |
| bool Map::should_be_fast_prototype_map() const { |
| if (!prototype_info()->IsPrototypeInfo()) return false; |
| return PrototypeInfo::cast(prototype_info())->should_be_fast_map(); |
| } |
| |
| void Map::set_elements_kind(ElementsKind elements_kind) { |
| CHECK_LT(static_cast<int>(elements_kind), kElementsKindCount); |
| set_bit_field2(Map::ElementsKindBits::update(bit_field2(), elements_kind)); |
| } |
| |
| ElementsKind Map::elements_kind() const { |
| return Map::ElementsKindBits::decode(bit_field2()); |
| } |
| |
| bool Map::has_fast_smi_elements() const { |
| return IsSmiElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_fast_object_elements() const { |
| return IsObjectElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_fast_smi_or_object_elements() const { |
| return IsSmiOrObjectElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_fast_double_elements() const { |
| return IsDoubleElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_fast_elements() const { |
| return IsFastElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_sloppy_arguments_elements() const { |
| return IsSloppyArgumentsElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_fast_sloppy_arguments_elements() const { |
| return elements_kind() == FAST_SLOPPY_ARGUMENTS_ELEMENTS; |
| } |
| |
| bool Map::has_fast_string_wrapper_elements() const { |
| return elements_kind() == FAST_STRING_WRAPPER_ELEMENTS; |
| } |
| |
| bool Map::has_fixed_typed_array_elements() const { |
| return IsFixedTypedArrayElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_dictionary_elements() const { |
| return IsDictionaryElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_frozen_or_sealed_elements() const { |
| return IsFrozenOrSealedElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_sealed_elements() const { |
| return IsSealedElementsKind(elements_kind()); |
| } |
| |
| bool Map::has_frozen_elements() const { |
| return IsFrozenElementsKind(elements_kind()); |
| } |
| |
| void Map::set_is_dictionary_map(bool value) { |
| uint32_t new_bit_field3 = IsDictionaryMapBit::update(bit_field3(), value); |
| new_bit_field3 = IsUnstableBit::update(new_bit_field3, value); |
| set_bit_field3(new_bit_field3); |
| } |
| |
| bool Map::is_dictionary_map() const { |
| return IsDictionaryMapBit::decode(bit_field3()); |
| } |
| |
| void Map::mark_unstable() { |
| set_bit_field3(IsUnstableBit::update(bit_field3(), true)); |
| } |
| |
| bool Map::is_stable() const { return !IsUnstableBit::decode(bit_field3()); } |
| |
| bool Map::CanBeDeprecated() const { |
| int descriptor = LastAdded(); |
| for (int i = 0; i <= descriptor; i++) { |
| PropertyDetails details = instance_descriptors()->GetDetails(i); |
| if (details.representation().IsNone()) return true; |
| if (details.representation().IsSmi()) return true; |
| if (details.representation().IsDouble()) return true; |
| if (details.representation().IsHeapObject()) return true; |
| if (details.kind() == kData && details.location() == kDescriptor) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void Map::NotifyLeafMapLayoutChange(Isolate* isolate) { |
| if (is_stable()) { |
| mark_unstable(); |
| dependent_code()->DeoptimizeDependentCodeGroup( |
| isolate, DependentCode::kPrototypeCheckGroup); |
| } |
| } |
| |
| bool Map::CanTransition() const { |
| // Only JSObject and subtypes have map transitions and back pointers. |
| return InstanceTypeChecker::IsJSObject(instance_type()); |
| } |
| |
| #define DEF_TESTER(Type, ...) \ |
| bool Map::Is##Type##Map() const { \ |
| return InstanceTypeChecker::Is##Type(instance_type()); \ |
| } |
| INSTANCE_TYPE_CHECKERS(DEF_TESTER) |
| #undef DEF_TESTER |
| |
| bool Map::IsBooleanMap() const { |
| return *this == GetReadOnlyRoots().boolean_map(); |
| } |
| |
| bool Map::IsNullOrUndefinedMap() const { |
| return *this == GetReadOnlyRoots().null_map() || |
| *this == GetReadOnlyRoots().undefined_map(); |
| } |
| |
| bool Map::IsPrimitiveMap() const { |
| return instance_type() <= LAST_PRIMITIVE_TYPE; |
| } |
| |
| HeapObject Map::prototype() const { |
| return HeapObject::cast(READ_FIELD(*this, kPrototypeOffset)); |
| } |
| |
| void Map::set_prototype(HeapObject value, WriteBarrierMode mode) { |
| DCHECK(value->IsNull() || value->IsJSReceiver()); |
| WRITE_FIELD(*this, kPrototypeOffset, value); |
| CONDITIONAL_WRITE_BARRIER(*this, kPrototypeOffset, value, mode); |
| } |
| |
| LayoutDescriptor Map::layout_descriptor_gc_safe() const { |
| DCHECK(FLAG_unbox_double_fields); |
| // The loaded value can be dereferenced on background thread to load the |
| // bitmap. We need acquire load in order to ensure that the bitmap |
| // initializing stores are also visible to the background thread. |
| Object layout_desc = ACQUIRE_READ_FIELD(*this, kLayoutDescriptorOffset); |
| return LayoutDescriptor::cast_gc_safe(layout_desc); |
| } |
| |
| bool Map::HasFastPointerLayout() const { |
| DCHECK(FLAG_unbox_double_fields); |
| // The loaded value is used for SMI check only and is not dereferenced, |
| // so relaxed load is safe. |
| Object layout_desc = RELAXED_READ_FIELD(*this, kLayoutDescriptorOffset); |
| return LayoutDescriptor::IsFastPointerLayout(layout_desc); |
| } |
| |
| void Map::UpdateDescriptors(Isolate* isolate, DescriptorArray descriptors, |
| LayoutDescriptor layout_desc, |
| int number_of_own_descriptors) { |
| SetInstanceDescriptors(isolate, descriptors, number_of_own_descriptors); |
| if (FLAG_unbox_double_fields) { |
| if (layout_descriptor()->IsSlowLayout()) { |
| set_layout_descriptor(layout_desc); |
| } |
| #ifdef VERIFY_HEAP |
| // TODO(ishell): remove these checks from VERIFY_HEAP mode. |
| if (FLAG_verify_heap) { |
| CHECK(layout_descriptor()->IsConsistentWithMap(*this)); |
| CHECK_EQ(Map::GetVisitorId(*this), visitor_id()); |
| } |
| #else |
| SLOW_DCHECK(layout_descriptor()->IsConsistentWithMap(*this)); |
| DCHECK(visitor_id() == Map::GetVisitorId(*this)); |
| #endif |
| } |
| } |
| |
| void Map::InitializeDescriptors(Isolate* isolate, DescriptorArray descriptors, |
| LayoutDescriptor layout_desc) { |
| SetInstanceDescriptors(isolate, descriptors, |
| descriptors->number_of_descriptors()); |
| |
| if (FLAG_unbox_double_fields) { |
| set_layout_descriptor(layout_desc); |
| #ifdef VERIFY_HEAP |
| // TODO(ishell): remove these checks from VERIFY_HEAP mode. |
| if (FLAG_verify_heap) { |
| CHECK(layout_descriptor()->IsConsistentWithMap(*this)); |
| } |
| #else |
| SLOW_DCHECK(layout_descriptor()->IsConsistentWithMap(*this)); |
| #endif |
| set_visitor_id(Map::GetVisitorId(*this)); |
| } |
| } |
| |
| void Map::set_bit_field3(uint32_t bits) { |
| RELAXED_WRITE_UINT32_FIELD(*this, kBitField3Offset, bits); |
| } |
| |
| uint32_t Map::bit_field3() const { |
| return RELAXED_READ_UINT32_FIELD(*this, kBitField3Offset); |
| } |
| |
| void Map::clear_padding() { |
| if (FIELD_SIZE(kOptionalPaddingOffset) == 0) return; |
| DCHECK_EQ(4, FIELD_SIZE(kOptionalPaddingOffset)); |
| memset(reinterpret_cast<void*>(address() + kOptionalPaddingOffset), 0, |
| FIELD_SIZE(kOptionalPaddingOffset)); |
| } |
| |
| LayoutDescriptor Map::GetLayoutDescriptor() const { |
| return FLAG_unbox_double_fields ? layout_descriptor() |
| : LayoutDescriptor::FastPointerLayout(); |
| } |
| |
| void Map::AppendDescriptor(Isolate* isolate, Descriptor* desc) { |
| DescriptorArray descriptors = instance_descriptors(); |
| int number_of_own_descriptors = NumberOfOwnDescriptors(); |
| DCHECK(descriptors->number_of_descriptors() == number_of_own_descriptors); |
| { |
| // The following two operations need to happen before the marking write |
| // barrier. |
| descriptors->Append(desc); |
| SetNumberOfOwnDescriptors(number_of_own_descriptors + 1); |
| MarkingBarrierForDescriptorArray(isolate->heap(), *this, descriptors, |
| number_of_own_descriptors + 1); |
| } |
| // Properly mark the map if the {desc} is an "interesting symbol". |
| if (desc->GetKey()->IsInterestingSymbol()) { |
| set_may_have_interesting_symbols(true); |
| } |
| PropertyDetails details = desc->GetDetails(); |
| if (details.location() == kField) { |
| DCHECK_GT(UnusedPropertyFields(), 0); |
| AccountAddedPropertyField(); |
| } |
| |
| // This function does not support appending double field descriptors and |
| // it should never try to (otherwise, layout descriptor must be updated too). |
| #ifdef DEBUG |
| DCHECK(details.location() != kField || !details.representation().IsDouble()); |
| #endif |
| } |
| |
| HeapObject Map::GetBackPointer() const { |
| Object object = constructor_or_backpointer(); |
| if (object->IsMap()) { |
| return Map::cast(object); |
| } |
| return GetReadOnlyRoots().undefined_value(); |
| } |
| |
| Map Map::ElementsTransitionMap() { |
| DisallowHeapAllocation no_gc; |
| // TODO(delphick): While it's safe to pass nullptr for Isolate* here as |
| // SearchSpecial doesn't need it, this is really ugly. Perhaps factor out a |
| // base class for methods not requiring an Isolate? |
| return TransitionsAccessor(nullptr, *this, &no_gc) |
| .SearchSpecial(GetReadOnlyRoots().elements_transition_symbol()); |
| } |
| |
| Object Map::prototype_info() const { |
| DCHECK(is_prototype_map()); |
| return READ_FIELD(*this, Map::kTransitionsOrPrototypeInfoOffset); |
| } |
| |
| void Map::set_prototype_info(Object value, WriteBarrierMode mode) { |
| CHECK(is_prototype_map()); |
| WRITE_FIELD(*this, Map::kTransitionsOrPrototypeInfoOffset, value); |
| CONDITIONAL_WRITE_BARRIER(*this, Map::kTransitionsOrPrototypeInfoOffset, |
| value, mode); |
| } |
| |
| void Map::SetBackPointer(Object value, WriteBarrierMode mode) { |
| CHECK_GE(instance_type(), FIRST_JS_RECEIVER_TYPE); |
| CHECK(value->IsMap()); |
| CHECK(GetBackPointer()->IsUndefined()); |
| CHECK_IMPLIES(value->IsMap(), Map::cast(value)->GetConstructor() == |
| constructor_or_backpointer()); |
| set_constructor_or_backpointer(value, mode); |
| } |
| |
| ACCESSORS(Map, dependent_code, DependentCode, kDependentCodeOffset) |
| ACCESSORS(Map, prototype_validity_cell, Object, kPrototypeValidityCellOffset) |
| ACCESSORS(Map, constructor_or_backpointer, Object, |
| kConstructorOrBackPointerOffset) |
| |
| bool Map::IsPrototypeValidityCellValid() const { |
| Object validity_cell = prototype_validity_cell(); |
| Object value = validity_cell->IsSmi() ? Smi::cast(validity_cell) |
| : Cell::cast(validity_cell)->value(); |
| return value == Smi::FromInt(Map::kPrototypeChainValid); |
| } |
| |
| Object Map::GetConstructor() const { |
| Object maybe_constructor = constructor_or_backpointer(); |
| // Follow any back pointers. |
| while (maybe_constructor->IsMap()) { |
| maybe_constructor = |
| Map::cast(maybe_constructor)->constructor_or_backpointer(); |
| } |
| return maybe_constructor; |
| } |
| |
| FunctionTemplateInfo Map::GetFunctionTemplateInfo() const { |
| Object constructor = GetConstructor(); |
| if (constructor->IsJSFunction()) { |
| DCHECK(JSFunction::cast(constructor)->shared()->IsApiFunction()); |
| return JSFunction::cast(constructor)->shared()->get_api_func_data(); |
| } |
| DCHECK(constructor->IsFunctionTemplateInfo()); |
| return FunctionTemplateInfo::cast(constructor); |
| } |
| |
| void Map::SetConstructor(Object constructor, WriteBarrierMode mode) { |
| // Never overwrite a back pointer with a constructor. |
| CHECK(!constructor_or_backpointer()->IsMap()); |
| set_constructor_or_backpointer(constructor, mode); |
| } |
| |
| Handle<Map> Map::CopyInitialMap(Isolate* isolate, Handle<Map> map) { |
| return CopyInitialMap(isolate, map, map->instance_size(), |
| map->GetInObjectProperties(), |
| map->UnusedPropertyFields()); |
| } |
| |
| bool Map::IsInobjectSlackTrackingInProgress() const { |
| return construction_counter() != Map::kNoSlackTracking; |
| } |
| |
| void Map::InobjectSlackTrackingStep(Isolate* isolate) { |
| // Slack tracking should only be performed on an initial map. |
| DCHECK(GetBackPointer()->IsUndefined()); |
| if (!IsInobjectSlackTrackingInProgress()) return; |
| int counter = construction_counter(); |
| set_construction_counter(counter - 1); |
| if (counter == kSlackTrackingCounterEnd) { |
| CompleteInobjectSlackTracking(isolate); |
| } |
| } |
| |
| int Map::SlackForArraySize(int old_size, int size_limit) { |
| const int max_slack = size_limit - old_size; |
| CHECK_LE(0, max_slack); |
| if (old_size < 4) { |
| DCHECK_LE(1, max_slack); |
| return 1; |
| } |
| return Min(max_slack, old_size / 4); |
| } |
| |
| int Map::InstanceSizeFromSlack(int slack) const { |
| return instance_size() - slack * kTaggedSize; |
| } |
| |
| OBJECT_CONSTRUCTORS_IMPL(NormalizedMapCache, WeakFixedArray) |
| CAST_ACCESSOR(NormalizedMapCache) |
| NEVER_READ_ONLY_SPACE_IMPL(NormalizedMapCache) |
| |
| int NormalizedMapCache::GetIndex(Handle<Map> map) { |
| return map->Hash() % NormalizedMapCache::kEntries; |
| } |
| |
| bool HeapObject::IsNormalizedMapCache() const { |
| if (!IsWeakFixedArray()) return false; |
| if (WeakFixedArray::cast(*this)->length() != NormalizedMapCache::kEntries) { |
| return false; |
| } |
| return true; |
| } |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #include "src/objects/object-macros-undef.h" |
| |
| #endif // V8_OBJECTS_MAP_INL_H_ |