1 // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- 2 // Copyright (c) 2005, Google Inc. 3 // All rights reserved. 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // --- 32 // This file is a compatibility layer that defines Google's version of 33 // command line flags that are used for configuration. 34 // 35 // We put flags into their own namespace. It is purposefully 36 // named in an opaque way that people should have trouble typing 37 // directly. The idea is that DEFINE puts the flag in the weird 38 // namespace, and DECLARE imports the flag from there into the 39 // current namespace. The net result is to force people to use 40 // DECLARE to get access to a flag, rather than saying 41 // extern bool FLAGS_logtostderr; 42 // or some such instead. We want this so we can put extra 43 // functionality (like sanity-checking) in DECLARE if we want, 44 // and make sure it is picked up everywhere. 45 // 46 // We also put the type of the variable in the namespace, so that 47 // people can't DECLARE_int32 something that they DEFINE_bool'd 48 // elsewhere. 49 #ifndef BASE_COMMANDLINEFLAGS_H_ 50 #define BASE_COMMANDLINEFLAGS_H_ 51 52 #include <config.h> 53 #include <string> 54 #include <string.h> // for memchr 55 #include <stdlib.h> // for getenv 56 #include "base/basictypes.h" 57 58 #define DECLARE_VARIABLE(type, name) \ 59 namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead { \ 60 extern PERFTOOLS_DLL_DECL type FLAGS_##name; \ 61 } \ 62 using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name 63 64 #define DEFINE_VARIABLE(type, name, value, meaning) \ 65 namespace FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead { \ 66 PERFTOOLS_DLL_DECL type FLAGS_##name(value); \ 67 char FLAGS_no##name; \ 68 } \ 69 using FLAG__namespace_do_not_use_directly_use_DECLARE_##type##_instead::FLAGS_##name 70 71 // bool specialization 72 #define DECLARE_bool(name) \ 73 DECLARE_VARIABLE(bool, name) 74 #define DEFINE_bool(name, value, meaning) \ 75 DEFINE_VARIABLE(bool, name, value, meaning) 76 77 // int32 specialization 78 #define DECLARE_int32(name) \ 79 DECLARE_VARIABLE(int32, name) 80 #define DEFINE_int32(name, value, meaning) \ 81 DEFINE_VARIABLE(int32, name, value, meaning) 82 83 // int64 specialization 84 #define DECLARE_int64(name) \ 85 DECLARE_VARIABLE(int64, name) 86 #define DEFINE_int64(name, value, meaning) \ 87 DEFINE_VARIABLE(int64, name, value, meaning) 88 89 #define DECLARE_uint64(name) \ 90 DECLARE_VARIABLE(uint64, name) 91 #define DEFINE_uint64(name, value, meaning) \ 92 DEFINE_VARIABLE(uint64, name, value, meaning) 93 94 // double specialization 95 #define DECLARE_double(name) \ 96 DECLARE_VARIABLE(double, name) 97 #define DEFINE_double(name, value, meaning) \ 98 DEFINE_VARIABLE(double, name, value, meaning) 99 100 // Special case for string, because we have to specify the namespace 101 // std::string, which doesn't play nicely with our FLAG__namespace hackery. 102 #define DECLARE_string(name) \ 103 namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead { \ 104 extern std::string FLAGS_##name; \ 105 } \ 106 using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name 107 #define DEFINE_string(name, value, meaning) \ 108 namespace FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead { \ 109 std::string FLAGS_##name(value); \ 110 char FLAGS_no##name; \ 111 } \ 112 using FLAG__namespace_do_not_use_directly_use_DECLARE_string_instead::FLAGS_##name 113 114 // implemented in sysinfo.cc 115 namespace tcmalloc { 116 namespace commandlineflags { 117 StringToBool(const char * value,bool def)118 inline bool StringToBool(const char *value, bool def) { 119 if (!value) { 120 return def; 121 } 122 switch (value[0]) { 123 case 't': 124 case 'T': 125 case 'y': 126 case 'Y': 127 case '1': 128 case '\0': 129 return true; 130 } 131 return false; 132 } 133 StringToInt(const char * value,int def)134 inline int StringToInt(const char *value, int def) { 135 if (!value) { 136 return def; 137 } 138 return strtol(value, NULL, 10); 139 } 140 StringToLongLong(const char * value,long long def)141 inline long long StringToLongLong(const char *value, long long def) { 142 if (!value) { 143 return def; 144 } 145 return strtoll(value, NULL, 10); 146 } 147 StringToDouble(const char * value,double def)148 inline double StringToDouble(const char *value, double def) { 149 if (!value) { 150 return def; 151 } 152 return strtod(value, NULL); 153 } 154 } 155 } 156 157 // These macros (could be functions, but I don't want to bother with a .cc 158 // file), make it easier to initialize flags from the environment. 159 160 #define EnvToString(envname, dflt) \ 161 (!getenv(envname) ? (dflt) : getenv(envname)) 162 163 #define EnvToBool(envname, dflt) \ 164 tcmalloc::commandlineflags::StringToBool(getenv(envname), dflt) 165 166 #define EnvToInt(envname, dflt) \ 167 tcmalloc::commandlineflags::StringToInt(getenv(envname), dflt) 168 169 #define EnvToInt64(envname, dflt) \ 170 tcmalloc::commandlineflags::StringToLongLong(getenv(envname), dflt) 171 172 #define EnvToDouble(envname, dflt) \ 173 tcmalloc::commandlineflags::StringToDouble(getenv(envname), dflt) 174 175 #endif // BASE_COMMANDLINEFLAGS_H_ 176