chromium/v8/include/cppgc/internal/member-storage.h

// Copyright 2022 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 INCLUDE_CPPGC_INTERNAL_MEMBER_STORAGE_H_
#define INCLUDE_CPPGC_INTERNAL_MEMBER_STORAGE_H_

#include <atomic>
#include <cstddef>
#include <type_traits>

#include "cppgc/internal/api-constants.h"
#include "cppgc/internal/logging.h"
#include "cppgc/sentinel-pointer.h"
#include "v8config.h"  // NOLINT(build/include_directory)

namespace cppgc {
namespace internal {

enum class WriteBarrierSlotType { … };

#if defined(CPPGC_POINTER_COMPRESSION)

#if defined(__clang__)
// Attribute const allows the compiler to assume that CageBaseGlobal::g_base_
// doesn't change (e.g. across calls) and thereby avoid redundant loads.
#define CPPGC_CONST …
#define CPPGC_REQUIRE_CONSTANT_INIT …
#else  // defined(__clang__)
#define CPPGC_CONST
#define CPPGC_REQUIRE_CONSTANT_INIT
#endif  // defined(__clang__)

class V8_EXPORT CageBaseGlobal final { … };

#undef CPPGC_REQUIRE_CONSTANT_INIT
#undef CPPGC_CONST

class V8_TRIVIAL_ABI CompressedPointer final { … };

#endif  // defined(CPPGC_POINTER_COMPRESSION)

class V8_TRIVIAL_ABI RawPointer final { … };

#if defined(CPPGC_POINTER_COMPRESSION)
DefaultMemberStorage;
#else   // !defined(CPPGC_POINTER_COMPRESSION)
using DefaultMemberStorage = RawPointer;
#endif  // !defined(CPPGC_POINTER_COMPRESSION)

}  // namespace internal
}  // namespace cppgc

#endif  // INCLUDE_CPPGC_INTERNAL_MEMBER_STORAGE_H_