52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
// Copyright 2018 The Abseil Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
#ifndef ABSL_BASE_INTERNAL_HIDE_PTR_H_
|
|
#define ABSL_BASE_INTERNAL_HIDE_PTR_H_
|
|
|
|
#include <cstdint>
|
|
|
|
#include "absl/base/config.h"
|
|
|
|
namespace absl {
|
|
ABSL_NAMESPACE_BEGIN
|
|
namespace base_internal {
|
|
|
|
// Arbitrary value with high bits set. Xor'ing with it is unlikely
|
|
// to map one valid pointer to another valid pointer.
|
|
constexpr uintptr_t HideMask() {
|
|
return (uintptr_t{0xF03A5F7BU} << (sizeof(uintptr_t) - 4) * 8) | 0xF03A5F7BU;
|
|
}
|
|
|
|
// Hide a pointer from the leak checker. For internal use only.
|
|
// Differs from absl::IgnoreLeak(ptr) in that absl::IgnoreLeak(ptr) causes ptr
|
|
// and all objects reachable from ptr to be ignored by the leak checker.
|
|
template <class T>
|
|
inline uintptr_t HidePtr(T* ptr) {
|
|
return reinterpret_cast<uintptr_t>(ptr) ^ HideMask();
|
|
}
|
|
|
|
// Return a pointer that has been hidden from the leak checker.
|
|
// For internal use only.
|
|
template <class T>
|
|
inline T* UnhidePtr(uintptr_t hidden) {
|
|
return reinterpret_cast<T*>(hidden ^ HideMask());
|
|
}
|
|
|
|
} // namespace base_internal
|
|
ABSL_NAMESPACE_END
|
|
} // namespace absl
|
|
|
|
#endif // ABSL_BASE_INTERNAL_HIDE_PTR_H_
|