rocksdb/util/gflags_compat.h

//  Copyright (c) 2017-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).

#pragma once
#include <gflags/gflags.h>

#include <functional>

#ifndef GFLAGS_NAMESPACE
// in case it's not defined in old versions, that's probably because it was
// still google by default.
#define GFLAGS_NAMESPACE google
#endif

#ifndef DEFINE_uint32
// DEFINE_uint32 / DECLARE_uint32 do not appear in older versions of gflags.
// These should be sane definitions for those versions.
#include <cstdint>
#define DEFINE_uint32(name, val, txt) \
  namespace gflags_compat {           \
  DEFINE_int32(name, val, txt);       \
  }                                   \
  uint32_t &FLAGS_##name =            \
      *reinterpret_cast<uint32_t *>(&gflags_compat::FLAGS_##name);

#define DECLARE_uint32(name) extern uint32_t &FLAGS_##name;
#endif  // !DEFINE_uint32