third_party/tcmalloc/vendor/src/base/commandlineflags.h

   1 // Copyright (c) 2005, Google Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
   6 // met:
   7 //
   8 //     * Redistributions of source code must retain the above copyright
   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //     * Neither the name of Google Inc. nor the names of its
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // This file is a compatibility layer that defines Google's version of
  32 // command line flags that are used for configuration.
  33 //
  34 // We put flags into their own namespace.  It is purposefully
  35 // named in an opaque way that people should have trouble typing
  36 // directly.  The idea is that DEFINE puts the flag in the weird
  37 // namespace, and DECLARE imports the flag from there into the
  38 // current namespace.  The net result is to force people to use
  39 // DECLARE to get access to a flag, rather than saying
  40 //   extern bool FLAGS_logtostderr;
  41 // or some such instead.  We want this so we can put extra
  42 // functionality (like sanity-checking) in DECLARE if we want,
  43 // and make sure it is picked up everywhere.
  44 //
  45 // We also put the type of the variable in the namespace, so that
  46 // people can't DECLARE_int32 something that they DEFINE_bool'd
  47 // elsewhere.
  48 #ifndef BASE_COMMANDLINEFLAGS_H_
  49 #define BASE_COMMANDLINEFLAGS_H_
  50
  51 #include <config.h>
  52 #include <string>
  53 #include <string.h>               // for memchr
  54 #include <stdlib.h>               // for getenv
  55 #include "base/basictypes.h"
  56
  57 #define DECLARE_VARIABLE(type, name)                                          \
  58   namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead {  \
  59   extern PERFTOOLS_DLL_DECL type FLAGS_##name;                                \
  60   }                                                                           \
  61   using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name
  62
  63 #define DEFINE_VARIABLE(type, name, value, meaning) \
  64   namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead {  \
  65   PERFTOOLS_DLL_DECL type FLAGS_##name(value);                                \
  66   char FLAGS_no##name;                                                        \
  67   }                                                                           \
  68   using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name
  69
  70 // bool specialization
  71 #define DECLARE_bool(name) \
  72   DECLARE_VARIABLE(bool, name)
  73 #define DEFINE_bool(name, value, meaning) \
  74   DEFINE_VARIABLE(bool, name, value, meaning)
  75
  76 // int32 specialization
  77 #define DECLARE_int32(name) \
  78   DECLARE_VARIABLE(int32, name)
  79 #define DEFINE_int32(name, value, meaning) \
  80   DEFINE_VARIABLE(int32, name, value, meaning)
  81
  82 // int64 specialization
  83 #define DECLARE_int64(name) \
  84   DECLARE_VARIABLE(int64, name)
  85 #define DEFINE_int64(name, value, meaning) \
  86   DEFINE_VARIABLE(int64, name, value, meaning)
  87
  88 #define DECLARE_uint64(name) \
  89   DECLARE_VARIABLE(uint64, name)
  90 #define DEFINE_uint64(name, value, meaning) \
  91   DEFINE_VARIABLE(uint64, name, value, meaning)
  92
  93 // double specialization
  94 #define DECLARE_double(name) \
  95   DECLARE_VARIABLE(double, name)
  96 #define DEFINE_double(name, value, meaning) \
  97   DEFINE_VARIABLE(double, name, value, meaning)
  98
  99 // Special case for string, because we have to specify the namespace
 100 // std::string, which doesn't play nicely with our FLAG__namespace hackery.
 101 #define DECLARE_string(name)                                          \
 102   namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead {  \
 103   extern std::string FLAGS_##name;                                                   \
 104   }                                                                           \
 105   using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name
 106 #define DEFINE_string(name, value, meaning) \
 107   namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead {  \
 108   std::string FLAGS_##name(value);                                                   \
 109   char FLAGS_no##name;                                                        \
 110   }                                                                           \
 111   using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name
 112
 113 // These macros (could be functions, but I don't want to bother with a .cc
 114 // file), make it easier to initialize flags from the environment.
 115
 116 #define EnvToString(envname, dflt)   \
 117   (!getenv(envname) ? (dflt) : getenv(envname))
 118
 119 #define EnvToBool(envname, dflt)   \
 120   (!getenv(envname) ? (dflt) : memchr("tTyY1\0", getenv(envname)[0], 6) != NULL)
 121
 122 #define EnvToInt(envname, dflt)  \
 123   (!getenv(envname) ? (dflt) : strtol(getenv(envname), NULL, 10))
 124
 125 #define EnvToInt64(envname, dflt)  \
 126   (!getenv(envname) ? (dflt) : strtoll(getenv(envname), NULL, 10))
 127
 128 #define EnvToDouble(envname, dflt)  \
 129   (!getenv(envname) ? (dflt) : strtod(getenv(envname), NULL))
 130
 131 #endif  // BASE_COMMANDLINEFLAGS_H_