tvl-depot/absl/base/internal/hide_ptr.h
Abseil Team 014f02a3ec - 45b4111d940009bc7b3ebf621c9cb9293c60344a Use copied value i in lambda by Abseil Team <absl-team@google.com>
- b726b3102f8439b8480b6ff52fc3660162fa0bd9 Fix MSVC compiler warning on 32-bit platforms (GitHub iss... by Derek Mauro <dmauro@google.com>
  - a8a29e636c85bd7d82c0cbc824a1c2e498764337 Explicitly forbid to specify the template parameter to Wr... by Abseil Team <absl-team@google.com>
  - 566a1d903266fdbfdcf758401c356a0c6703422d Add missing license header to BUILD file. by Alex Strelnikov <strel@google.com>
  - ef1c0642cde0bbad62bbb30715256b232a4ab817 Fix BUILD file header. by Alex Strelnikov <strel@google.com>
  - b6e2cf00f808ee32b9eb7b3226af79d628742c20 Release GraphCycles microbenchmark. by Alex Strelnikov <strel@google.com>
  - f592d78f549e7a242bf2bb4858a26645a655eac3 Release Mutex microbenchmarks. by Alex Strelnikov <strel@google.com>

GitOrigin-RevId: 45b4111d940009bc7b3ebf621c9cb9293c60344a
Change-Id: I82885ae176952a764574c6d4616e312a977407b2
2018-05-23 11:44:15 -04:00

49 lines
1.7 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
//
// 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() {
static_assert(sizeof(uintptr_t) == 4 || sizeof(uintptr_t) == 8,
"uintptr_t must be 32 or 64 bits");
return sizeof(uintptr_t) == 8 ? 0xF03A5F7BF03A5F7BULL : 0xF03A5F7BUL;
}
// 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_