tvl-depot/absl/base/internal/hide_ptr.h

48 lines
1.6 KiB
C
Raw Normal View History

// 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
//
// http://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>
namespace absl {
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() {
- e2f6b8ac647271815b4fed2991f405524dd762c3 Release cctz microbenchmarks. by Alex Strelnikov <strel@google.com> - 924ba2a3f9fca695d73c6bf491d20669e2b96b8e Changed RawPtr to use std::addressof() instead of operato... by Abseil Team <absl-team@google.com> - e8cf67f9fa74d4c5632da35547025ad2301c6819 Import of CCTZ from GitHub. by Alex Strelnikov <strel@google.com> - 2ece8a96611afcddd7b91e0197dadb896248250c Abandon ".inc" files in favor of ".h" headers. by Jorg Brown <jorg@google.com> - 37f5ed5da4058f90fb3e6a2733fce5b1fd0aaedf Add exception safety tests for absl::optional<T> by Abseil Team <absl-team@google.com> - 337f995a866b8f905f64ca6b271b5fec8f248a60 Update WORKSPACE to grab specific commits of dependencies... by Alex Strelnikov <strel@google.com> - 93e5b134607a554993387ad913e6c1621606004b Release Charmap microbenchmark. by Alex Strelnikov <strel@google.com> - 95c2e29b6d93ec1334484ee37d91f63101c45307 Release OStringStream microbenchmarks. by Alex Strelnikov <strel@google.com> - 250f51839ed26dd1e6b658d35aa291413e5f4825 Internal change by Greg Falcon <gfalcon@google.com> - ce34900fa3d1a95a8446bc943cdd801fac95be25 Improve compatibility of cctz cc_test targets for portabl... by Shaindel Schwartz <shaindel@google.com> - ce7e31dbf2c1ee93c79aae5b7dc7c603cb4babcf Improve portability of cc_tests. (Mark more tests that ca... by Abseil Team <absl-team@google.com> - dfcd4e455923703c1a1dcd523c5f915f7990fa2a Accept strings with custom allocators as arguments to abs... by Greg Falcon <gfalcon@google.com> - 2946b41ed3d5b8b5a8dc11182e443cf1ab6e3bde Link against benchmark_main instead of using BENCHMARK_MA... by Alex Strelnikov <strel@google.com> - f09de9e03bf8edd363069c4b352d8009423f531c Adds link to doc about the formats allowed by SimpleAtof(... by Greg Miller <jgm@google.com> - 59b0977e7a308e0800277886cf60226b2cc426a1 Simplify the HideMask() calculation so that it doesn't us... by Jorg Brown <jorg@google.com> GitOrigin-RevId: e2f6b8ac647271815b4fed2991f405524dd762c3 Change-Id: Ib9c8547ed7fe217fad6cb3ab1362e96181aa5cfa
2018-05-31 21:26:35 +02:00
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
} // namespace absl
#endif // ABSL_BASE_INTERNAL_HIDE_PTR_H_