// 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_DATA_HANDLER_H_
|
#define V8_OBJECTS_DATA_HANDLER_H_
|
|
#include "src/objects.h"
|
|
// Has to be the last include (doesn't have include guards):
|
#include "src/objects/object-macros.h"
|
|
namespace v8 {
|
namespace internal {
|
|
// DataHandler is a base class for load and store handlers that can't be
|
// encoded in one Smi. Kind of a handler can be deduced from instance type.
|
class DataHandler : public Struct {
|
public:
|
// [smi_handler]: A Smi which encodes a handler or Code object (we still
|
// use code handlers for accessing lexical environment variables, but soon
|
// only smi handlers will remain). See LoadHandler and StoreHandler for
|
// details about encoding.
|
DECL_ACCESSORS(smi_handler, Object)
|
|
// [validity_cell]: A validity Cell that guards prototype chain modifications.
|
DECL_ACCESSORS(validity_cell, Object)
|
|
// Returns number of optional data fields available in the object.
|
inline int data_field_count() const;
|
|
// [data1-3]: These are optional general-purpose fields whose content and
|
// presence depends on the handler kind.
|
DECL_ACCESSORS(data1, MaybeObject)
|
DECL_ACCESSORS(data2, MaybeObject)
|
DECL_ACCESSORS(data3, MaybeObject)
|
|
// Layout description.
|
#define DATA_HANDLER_FIELDS(V) \
|
V(kSmiHandlerOffset, kPointerSize) \
|
V(kValidityCellOffset, kPointerSize) \
|
V(kSizeWithData0, 0) \
|
V(kData1Offset, kPointerSize) \
|
V(kSizeWithData1, 0) \
|
V(kData2Offset, kPointerSize) \
|
V(kSizeWithData2, 0) \
|
V(kData3Offset, kPointerSize) \
|
V(kSizeWithData3, 0)
|
|
DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, DATA_HANDLER_FIELDS)
|
#undef DATA_HANDLER_FIELDS
|
|
DECL_CAST(DataHandler)
|
|
DECL_VERIFIER(DataHandler)
|
|
class BodyDescriptor;
|
};
|
|
} // namespace internal
|
} // namespace v8
|
|
#include "src/objects/object-macros-undef.h"
|
|
#endif // V8_OBJECTS_DATA_HANDLER_H_
|
