| // 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. | |
| 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 | |