henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2006, Google Inc. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * 3. The name of the author may not be used to endorse or promote products |
| 14 | * derived from this software without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 17 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 18 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| 19 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 20 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 22 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 23 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 24 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 25 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | |
| 29 | // Originally comes from shared/commandlineflags/flags.h |
| 30 | |
| 31 | // Flags are defined and declared using DEFINE_xxx and DECLARE_xxx macros, |
| 32 | // where xxx is the flag type. Flags are referred to via FLAG_yyy, |
| 33 | // where yyy is the flag name. For intialization and iteration of flags, |
| 34 | // see the FlagList class. For full programmatic access to any |
| 35 | // flag, see the Flag class. |
| 36 | // |
| 37 | // The implementation only relies and basic C++ functionality |
| 38 | // and needs no special library or STL support. |
| 39 | |
| 40 | #ifndef TALK_BASE_FLAGS_H__ |
| 41 | #define TALK_BASE_FLAGS_H__ |
| 42 | |
| 43 | #include <assert.h> |
| 44 | |
| 45 | #include "talk/base/checks.h" |
| 46 | #include "talk/base/common.h" |
| 47 | |
| 48 | // Internal use only. |
| 49 | union FlagValue { |
| 50 | // Note: Because in C++ non-bool values are silently converted into |
| 51 | // bool values ('bool b = "false";' results in b == true!), we pass |
| 52 | // and int argument to New_BOOL as this appears to be safer - sigh. |
| 53 | // In particular, it prevents the (not uncommon!) bug where a bool |
| 54 | // flag is defined via: DEFINE_bool(flag, "false", "some comment");. |
| 55 | static FlagValue New_BOOL(int b) { |
| 56 | FlagValue v; |
| 57 | v.b = (b != 0); |
| 58 | return v; |
| 59 | } |
| 60 | |
| 61 | static FlagValue New_INT(int i) { |
| 62 | FlagValue v; |
| 63 | v.i = i; |
| 64 | return v; |
| 65 | } |
| 66 | |
| 67 | static FlagValue New_FLOAT(float f) { |
| 68 | FlagValue v; |
| 69 | v.f = f; |
| 70 | return v; |
| 71 | } |
| 72 | |
| 73 | static FlagValue New_STRING(const char* s) { |
| 74 | FlagValue v; |
| 75 | v.s = s; |
| 76 | return v; |
| 77 | } |
| 78 | |
| 79 | bool b; |
| 80 | int i; |
| 81 | double f; |
| 82 | const char* s; |
| 83 | }; |
| 84 | |
| 85 | |
| 86 | // Each flag can be accessed programmatically via a Flag object. |
| 87 | class Flag { |
| 88 | public: |
| 89 | enum Type { BOOL, INT, FLOAT, STRING }; |
| 90 | |
| 91 | // Internal use only. |
| 92 | Flag(const char* file, const char* name, const char* comment, |
| 93 | Type type, void* variable, FlagValue default_); |
| 94 | |
| 95 | // General flag information |
| 96 | const char* file() const { return file_; } |
| 97 | const char* name() const { return name_; } |
| 98 | const char* comment() const { return comment_; } |
| 99 | |
| 100 | // Flag type |
| 101 | Type type() const { return type_; } |
| 102 | |
| 103 | // Flag variables |
| 104 | bool* bool_variable() const { |
| 105 | assert(type_ == BOOL); |
| 106 | return &variable_->b; |
| 107 | } |
| 108 | |
| 109 | int* int_variable() const { |
| 110 | assert(type_ == INT); |
| 111 | return &variable_->i; |
| 112 | } |
| 113 | |
| 114 | double* float_variable() const { |
| 115 | assert(type_ == FLOAT); |
| 116 | return &variable_->f; |
| 117 | } |
| 118 | |
| 119 | const char** string_variable() const { |
| 120 | assert(type_ == STRING); |
| 121 | return &variable_->s; |
| 122 | } |
| 123 | |
| 124 | // Default values |
| 125 | bool bool_default() const { |
| 126 | assert(type_ == BOOL); |
| 127 | return default_.b; |
| 128 | } |
| 129 | |
| 130 | int int_default() const { |
| 131 | assert(type_ == INT); |
| 132 | return default_.i; |
| 133 | } |
| 134 | |
| 135 | double float_default() const { |
| 136 | assert(type_ == FLOAT); |
| 137 | return default_.f; |
| 138 | } |
| 139 | |
| 140 | const char* string_default() const { |
| 141 | assert(type_ == STRING); |
| 142 | return default_.s; |
| 143 | } |
| 144 | |
| 145 | // Resets a flag to its default value |
| 146 | void SetToDefault(); |
| 147 | |
| 148 | // Iteration support |
| 149 | Flag* next() const { return next_; } |
| 150 | |
| 151 | // Prints flag information. The current flag value is only printed |
| 152 | // if print_current_value is set. |
| 153 | void Print(bool print_current_value); |
| 154 | |
| 155 | private: |
| 156 | const char* file_; |
| 157 | const char* name_; |
| 158 | const char* comment_; |
| 159 | |
| 160 | Type type_; |
| 161 | FlagValue* variable_; |
| 162 | FlagValue default_; |
| 163 | |
| 164 | Flag* next_; |
| 165 | |
| 166 | friend class FlagList; // accesses next_ |
| 167 | }; |
| 168 | |
| 169 | |
| 170 | // Internal use only. |
| 171 | #define DEFINE_FLAG(type, c_type, name, default, comment) \ |
| 172 | /* define and initialize the flag */ \ |
| 173 | c_type FLAG_##name = (default); \ |
| 174 | /* register the flag */ \ |
| 175 | static Flag Flag_##name(__FILE__, #name, (comment), \ |
| 176 | Flag::type, &FLAG_##name, \ |
| 177 | FlagValue::New_##type(default)) |
| 178 | |
| 179 | |
| 180 | // Internal use only. |
| 181 | #define DECLARE_FLAG(c_type, name) \ |
| 182 | /* declare the external flag */ \ |
| 183 | extern c_type FLAG_##name |
| 184 | |
| 185 | |
| 186 | // Use the following macros to define a new flag: |
| 187 | #define DEFINE_bool(name, default, comment) \ |
| 188 | DEFINE_FLAG(BOOL, bool, name, default, comment) |
| 189 | #define DEFINE_int(name, default, comment) \ |
| 190 | DEFINE_FLAG(INT, int, name, default, comment) |
| 191 | #define DEFINE_float(name, default, comment) \ |
| 192 | DEFINE_FLAG(FLOAT, double, name, default, comment) |
| 193 | #define DEFINE_string(name, default, comment) \ |
| 194 | DEFINE_FLAG(STRING, const char*, name, default, comment) |
| 195 | |
| 196 | |
| 197 | // Use the following macros to declare a flag defined elsewhere: |
| 198 | #define DECLARE_bool(name) DECLARE_FLAG(bool, name) |
| 199 | #define DECLARE_int(name) DECLARE_FLAG(int, name) |
| 200 | #define DECLARE_float(name) DECLARE_FLAG(double, name) |
| 201 | #define DECLARE_string(name) DECLARE_FLAG(const char*, name) |
| 202 | |
| 203 | |
| 204 | // The global list of all flags. |
| 205 | class FlagList { |
| 206 | public: |
| 207 | FlagList(); |
| 208 | |
| 209 | // The NULL-terminated list of all flags. Traverse with Flag::next(). |
| 210 | static Flag* list() { return list_; } |
| 211 | |
| 212 | // If file != NULL, prints information for all flags defined in file; |
| 213 | // otherwise prints information for all flags in all files. The current |
| 214 | // flag value is only printed if print_current_value is set. |
| 215 | static void Print(const char* file, bool print_current_value); |
| 216 | |
| 217 | // Lookup a flag by name. Returns the matching flag or NULL. |
| 218 | static Flag* Lookup(const char* name); |
| 219 | |
| 220 | // Helper function to parse flags: Takes an argument arg and splits it into |
| 221 | // a flag name and flag value (or NULL if they are missing). is_bool is set |
| 222 | // if the arg started with "-no" or "--no". The buffer may be used to NUL- |
| 223 | // terminate the name, it must be large enough to hold any possible name. |
| 224 | static void SplitArgument(const char* arg, |
| 225 | char* buffer, int buffer_size, |
| 226 | const char** name, const char** value, |
| 227 | bool* is_bool); |
| 228 | |
| 229 | // Set the flag values by parsing the command line. If remove_flags |
| 230 | // is set, the flags and associated values are removed from (argc, |
| 231 | // argv). Returns 0 if no error occurred. Otherwise, returns the |
| 232 | // argv index > 0 for the argument where an error occurred. In that |
| 233 | // case, (argc, argv) will remain unchanged indepdendent of the |
| 234 | // remove_flags value, and no assumptions about flag settings should |
| 235 | // be made. |
| 236 | // |
| 237 | // The following syntax for flags is accepted (both '-' and '--' are ok): |
| 238 | // |
| 239 | // --flag (bool flags only) |
| 240 | // --noflag (bool flags only) |
| 241 | // --flag=value (non-bool flags only, no spaces around '=') |
| 242 | // --flag value (non-bool flags only) |
| 243 | static int SetFlagsFromCommandLine(int* argc, |
| 244 | const char** argv, |
| 245 | bool remove_flags); |
| 246 | static inline int SetFlagsFromCommandLine(int* argc, |
| 247 | char** argv, |
| 248 | bool remove_flags) { |
| 249 | return SetFlagsFromCommandLine(argc, const_cast<const char**>(argv), |
| 250 | remove_flags); |
| 251 | } |
| 252 | |
| 253 | // Registers a new flag. Called during program initialization. Not |
| 254 | // thread-safe. |
| 255 | static void Register(Flag* flag); |
| 256 | |
| 257 | private: |
| 258 | static Flag* list_; |
| 259 | }; |
| 260 | |
| 261 | #ifdef WIN32 |
| 262 | // A helper class to translate Windows command line arguments into UTF8, |
| 263 | // which then allows us to just pass them to the flags system. |
| 264 | // This encapsulates all the work of getting the command line and translating |
| 265 | // it to an array of 8-bit strings; all you have to do is create one of these, |
| 266 | // and then call argc() and argv(). |
| 267 | class WindowsCommandLineArguments { |
| 268 | public: |
| 269 | WindowsCommandLineArguments(); |
| 270 | ~WindowsCommandLineArguments(); |
| 271 | |
| 272 | int argc() { return argc_; } |
| 273 | char **argv() { return argv_; } |
| 274 | private: |
| 275 | int argc_; |
| 276 | char **argv_; |
| 277 | |
| 278 | private: |
| 279 | DISALLOW_EVIL_CONSTRUCTORS(WindowsCommandLineArguments); |
| 280 | }; |
| 281 | #endif // WIN32 |
| 282 | |
| 283 | |
| 284 | #endif // SHARED_COMMANDLINEFLAGS_FLAGS_H__ |