// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- // Copyright (c) 2005, Google Inc. // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // --- // This file is a compatibility layer that defines Google's version of // command line flags that are used for configuration. // // We put flags into their own namespace. It is purposefully // named in an opaque way that people should have trouble typing // directly. The idea is that DEFINE puts the flag in the weird // namespace, and DECLARE imports the flag from there into the // current namespace. The net result is to force people to use // DECLARE to get access to a flag, rather than saying // extern bool FLAGS_logtostderr; // or some such instead. We want this so we can put extra // functionality (like sanity-checking) in DECLARE if we want, // and make sure it is picked up everywhere. // // We also put the type of the variable in the namespace, so that // people can't DECLARE_int32 something that they DEFINE_bool'd // elsewhere. #ifndef BASE_COMMANDLINEFLAGS_H_ #define BASE_COMMANDLINEFLAGS_H_ #include #include #include // for memchr #include // for getenv #include "base/basictypes.h" #define DECLARE_VARIABLE(type, name) \ namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead { \ extern PERFTOOLS_DLL_DECL type FLAGS_##name; \ } \ using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name #define DEFINE_VARIABLE(type, name, value, meaning) \ namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead { \ PERFTOOLS_DLL_DECL type FLAGS_##name(value); \ char FLAGS_no##name; \ } \ using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name // bool specialization #define DECLARE_bool(name) \ DECLARE_VARIABLE(bool, name) #define DEFINE_bool(name, value, meaning) \ DEFINE_VARIABLE(bool, name, value, meaning) // int32 specialization #define DECLARE_int32(name) \ DECLARE_VARIABLE(int32, name) #define DEFINE_int32(name, value, meaning) \ DEFINE_VARIABLE(int32, name, value, meaning) // int64 specialization #define DECLARE_int64(name) \ DECLARE_VARIABLE(int64, name) #define DEFINE_int64(name, value, meaning) \ DEFINE_VARIABLE(int64, name, value, meaning) #define DECLARE_uint64(name) \ DECLARE_VARIABLE(uint64, name) #define DEFINE_uint64(name, value, meaning) \ DEFINE_VARIABLE(uint64, name, value, meaning) // double specialization #define DECLARE_double(name) \ DECLARE_VARIABLE(double, name) #define DEFINE_double(name, value, meaning) \ DEFINE_VARIABLE(double, name, value, meaning) // Special case for string, because we have to specify the namespace // std::string, which doesn't play nicely with our FLAG__namespace hackery. #define DECLARE_string(name) \ namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead { \ extern std::string FLAGS_##name; \ } \ using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name #define DEFINE_string(name, value, meaning) \ namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead { \ std::string FLAGS_##name(value); \ char FLAGS_no##name; \ } \ using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name // implemented in sysinfo.cc namespace tcmalloc { namespace commandlineflags { inline bool StringToBool(const char *value, bool def) { if (!value) { return def; } return memchr("tTyY1\0", value[0], 6) != NULL; } inline int StringToInt(const char *value, int def) { if (!value) { return def; } return strtol(value, NULL, 10); } inline long long StringToLongLong(const char *value, long long def) { if (!value) { return def; } return strtoll(value, NULL, 10); } inline double StringToDouble(const char *value, double def) { if (!value) { return def; } return strtod(value, NULL); } } } // These macros (could be functions, but I don't want to bother with a .cc // file), make it easier to initialize flags from the environment. #define EnvToString(envname, dflt) \ (!getenv(envname) ? (dflt) : getenv(envname)) #define EnvToBool(envname, dflt) \ tcmalloc::commandlineflags::StringToBool(getenv(envname), dflt) #define EnvToInt(envname, dflt) \ tcmalloc::commandlineflags::StringToInt(getenv(envname), dflt) #define EnvToInt64(envname, dflt) \ tcmalloc::commandlineflags::StringToLongLong(getenv(envname), dflt) #define EnvToDouble(envname, dflt) \ tcmalloc::commandlineflags::StringToDouble(getenv(envname), dflt) #endif // BASE_COMMANDLINEFLAGS_H_