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Diffstat (limited to 'src/base/commandlineflags.h')
| -rw-r--r-- | src/base/commandlineflags.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/base/commandlineflags.h b/src/base/commandlineflags.h new file mode 100644 index 000000000000..c8d50890269a --- /dev/null +++ b/src/base/commandlineflags.h @@ -0,0 +1,133 @@ +// Copyright (c) 2008, 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 "config.h" +#include <string> +#include <string.h> // for memchr +#include <stdlib.h> // for getenv + +#ifdef HAVE_LIB_GFLAGS + +#include <gflags/gflags.h> + +#else + +#include "glog/logging.h" + +#define DECLARE_VARIABLE(type, shorttype, name, tn) \ + namespace fL##shorttype { \ + extern GOOGLE_GLOG_DLL_DECL type FLAGS_##name; \ + } \ + using fL##shorttype::FLAGS_##name +#define DEFINE_VARIABLE(type, shorttype, name, value, meaning, tn) \ + namespace fL##shorttype { \ + GOOGLE_GLOG_DLL_DECL type FLAGS_##name(value); \ + char FLAGS_no##name; \ + } \ + using fL##shorttype::FLAGS_##name + +// bool specialization +#define DECLARE_bool(name) \ + DECLARE_VARIABLE(bool, B, name, bool) +#define DEFINE_bool(name, value, meaning) \ + DEFINE_VARIABLE(bool, B, name, value, meaning, bool) + +// int32 specialization +#define DECLARE_int32(name) \ + DECLARE_VARIABLE(GOOGLE_NAMESPACE::int32, I, name, int32) +#define DEFINE_int32(name, value, meaning) \ + DEFINE_VARIABLE(GOOGLE_NAMESPACE::int32, I, name, value, meaning, int32) + +// 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 fLS { \ + extern GOOGLE_GLOG_DLL_DECL std::string& FLAGS_##name; \ + } \ + using fLS::FLAGS_##name +#define DEFINE_string(name, value, meaning) \ + namespace fLS { \ + std::string FLAGS_##name##_buf(value); \ + GOOGLE_GLOG_DLL_DECL std::string& FLAGS_##name = FLAGS_##name##_buf; \ + char FLAGS_no##name; \ + } \ + using fLS::FLAGS_##name + +#endif // HAVE_LIB_GFLAGS + +// Define GLOG_DEFINE_* using DEFINE_* . By using these macros, we +// have GLOG_* environ variables even if we have gflags installed. +// +// If both an environment variable and a flag are specified, the value +// specified by a flag wins. E.g., if GLOG_v=0 and --v=1, the +// verbosity will be 1, not 0. + +#define GLOG_DEFINE_bool(name, value, meaning) \ + DEFINE_bool(name, EnvToBool("GLOG_" #name, value), meaning) + +#define GLOG_DEFINE_int32(name, value, meaning) \ + DEFINE_int32(name, EnvToInt("GLOG_" #name, value), meaning) + +#define GLOG_DEFINE_string(name, value, meaning) \ + DEFINE_string(name, EnvToString("GLOG_" #name, value), meaning) + +// 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) \ + (!getenv(envname) ? (dflt) : memchr("tTyY1\0", getenv(envname)[0], 6) != NULL) + +#define EnvToInt(envname, dflt) \ + (!getenv(envname) ? (dflt) : strtol(getenv(envname), NULL, 10)) + +#endif // BASE_COMMANDLINEFLAGS_H__ |