diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/hide_ptr.h')
-rw-r--r-- | third_party/abseil_cpp/absl/base/internal/hide_ptr.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/hide_ptr.h b/third_party/abseil_cpp/absl/base/internal/hide_ptr.h new file mode 100644 index 000000000000..1dba80909a9b --- /dev/null +++ b/third_party/abseil_cpp/absl/base/internal/hide_ptr.h @@ -0,0 +1,51 @@ +// 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_ |