| // Copyright 2018 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_PROTOTYPE_INFO_H_ |
| #define V8_OBJECTS_PROTOTYPE_INFO_H_ |
| |
| #include "src/objects.h" |
| #include "src/objects/fixed-array.h" |
| #include "src/objects/struct.h" |
| |
| // Has to be the last include (doesn't have include guards): |
| #include "src/objects/object-macros.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // Container for metadata stored on each prototype map. |
| class PrototypeInfo : public Struct { |
| public: |
| static const int UNREGISTERED = -1; |
| |
| // [module_namespace]: A backpointer to JSModuleNamespace from its |
| // PrototypeInfo (or undefined). This field is only used for JSModuleNamespace |
| // maps. TODO(jkummerow): Figure out if there's a way to store the namespace |
| // pointer elsewhere to save memory. |
| DECL_ACCESSORS(module_namespace, Object) |
| |
| // [prototype_users]: WeakArrayList containing weak references to maps using |
| // this prototype, or Smi(0) if uninitialized. |
| DECL_ACCESSORS(prototype_users, Object) |
| |
| // [object_create_map]: A field caching the map for Object.create(prototype). |
| static inline void SetObjectCreateMap(Handle<PrototypeInfo> info, |
| Handle<Map> map); |
| inline Map ObjectCreateMap(); |
| inline bool HasObjectCreateMap(); |
| |
| // [registry_slot]: Slot in prototype's user registry where this user |
| // is stored. Returns UNREGISTERED if this prototype has not been registered. |
| inline int registry_slot() const; |
| inline void set_registry_slot(int slot); |
| |
| // [bit_field] |
| inline int bit_field() const; |
| inline void set_bit_field(int bit_field); |
| |
| DECL_BOOLEAN_ACCESSORS(should_be_fast_map) |
| |
| DECL_CAST(PrototypeInfo) |
| |
| // Dispatched behavior. |
| DECL_PRINTER(PrototypeInfo) |
| DECL_VERIFIER(PrototypeInfo) |
| |
| DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, |
| TORQUE_GENERATED_PROTOTYPE_INFO_FIELDS) |
| |
| // Bit field usage. |
| static const int kShouldBeFastBit = 0; |
| |
| class BodyDescriptor; |
| |
| private: |
| DECL_ACCESSORS(object_create_map, MaybeObject) |
| |
| OBJECT_CONSTRUCTORS(PrototypeInfo, Struct); |
| }; |
| |
| // A growing array with an additional API for marking slots "empty". When adding |
| // new elements, we reuse the empty slots instead of growing the array. |
| class V8_EXPORT_PRIVATE PrototypeUsers : public WeakArrayList { |
| public: |
| static Handle<WeakArrayList> Add(Isolate* isolate, |
| Handle<WeakArrayList> array, |
| Handle<Map> value, int* assigned_index); |
| |
| static inline void MarkSlotEmpty(WeakArrayList array, int index); |
| |
| // The callback is called when a weak pointer to HeapObject "object" is moved |
| // from index "from_index" to index "to_index" during compaction. The callback |
| // must not cause GC. |
| using CompactionCallback = void (*)(HeapObject object, int from_index, |
| int to_index); |
| static WeakArrayList Compact( |
| Handle<WeakArrayList> array, Heap* heap, CompactionCallback callback, |
| AllocationType allocation = AllocationType::kYoung); |
| |
| #ifdef VERIFY_HEAP |
| static void Verify(WeakArrayList array); |
| #endif // VERIFY_HEAP |
| |
| static const int kEmptySlotIndex = 0; |
| static const int kFirstIndex = 1; |
| |
| static const int kNoEmptySlotsMarker = 0; |
| |
| private: |
| static inline Smi empty_slot_index(WeakArrayList array); |
| static inline void set_empty_slot_index(WeakArrayList array, int index); |
| |
| static void IsSlotEmpty(WeakArrayList array, int index); |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(PrototypeUsers); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #include "src/objects/object-macros-undef.h" |
| |
| #endif // V8_OBJECTS_PROTOTYPE_INFO_H_ |