1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SK_COMMAND_LINE_FLAGS_H 9 #define SK_COMMAND_LINE_FLAGS_H 10 11 #include "SkString.h" 12 #include "SkTArray.h" 13 #include "SkTDArray.h" 14 15 /** 16 * Including this file (and compiling SkCommandLineFlags.cpp) provides command line 17 * parsing. In order to use it, use the following macros in global 18 * namespace: 19 * 20 * DEFINE_bool(name, defaultValue, helpString); 21 * DEFINE_string(name, defaultValue, helpString); 22 * DEFINE_int32(name, defaultValue, helpString); 23 * DEFINE_double(name, defaultValue, helpString); 24 * 25 * Then, in main, call SkCommandLineFlags::SetUsage() to describe usage and call 26 * SkCommandLineFlags::Parse() to parse the flags. Henceforth, each flag can 27 * be referenced using 28 * 29 * FLAGS_name 30 * 31 * For example, the line 32 * 33 * DEFINE_bool(boolean, false, "The variable boolean does such and such"); 34 * 35 * will create the following variable: 36 * 37 * bool FLAGS_boolean; 38 * 39 * which will initially be set to false, and can be set to true by using the 40 * flag "--boolean" on the commandline. "--noboolean" will set FLAGS_boolean 41 * to false. FLAGS_boolean can also be set using "--boolean=true" or 42 * "--boolean true" (where "true" can be replaced by "false", "TRUE", "FALSE", 43 * "1" or "0"). 44 * 45 * The helpString will be printed if the help flag (-h or -help) is used. 46 * 47 * Similarly, the line 48 * 49 * DEFINE_int32(integer, .., ..); 50 * 51 * will create 52 * 53 * int32_t FLAGS_integer; 54 * 55 * and 56 * 57 * DEFINE_double(real, .., ..); 58 * 59 * will create 60 * 61 * double FLAGS_real; 62 * 63 * These flags can be set by specifying, for example, "--integer 7" and 64 * "--real 3.14" on the command line. 65 * 66 * Unlike the others, the line 67 * 68 * DEFINE_string(args, .., ..); 69 * 70 * creates an array: 71 * 72 * SkCommandLineFlags::StringArray FLAGS_args; 73 * 74 * If the default value is the empty string, FLAGS_args will default to a size 75 * of zero. Otherwise it will default to a size of 1 with the default string 76 * as its value. All strings that follow the flag on the command line (until 77 * a string that begins with '-') will be entries in the array. 78 * 79 * Any flag can be referenced from another file after using the following: 80 * 81 * DECLARE_x(name); 82 * 83 * (where 'x' is the type specified in the DEFINE). 84 * 85 * Inspired by gflags (https://code.google.com/p/gflags/). Is not quite as 86 * robust as gflags, but suits our purposes. For example, allows creating 87 * a flag -h or -help which will never be used, since SkCommandLineFlags handles it. 88 * SkCommandLineFlags will also allow creating --flag and --noflag. Uses the same input 89 * format as gflags and creates similarly named variables (i.e. FLAGS_name). 90 * Strings are handled differently (resulting variable will be an array of 91 * strings) so that a flag can be followed by multiple parameters. 92 */ 93 94 class SkFlagInfo; 95 96 class SkCommandLineFlags { 97 98 public: 99 /** 100 * Call to set the help message to be displayed. Should be called before 101 * Parse. 102 */ 103 static void SetUsage(const char* usage); 104 105 /** 106 * Call at the beginning of main to parse flags created by DEFINE_x, above. 107 * Must only be called once. 108 */ 109 static void Parse(int argc, char** argv); 110 111 /* Takes a list of the form [~][^]match[$] 112 ~ causes a matching test to always be skipped 113 ^ requires the start of the test to match 114 $ requires the end of the test to match 115 ^ and $ requires an exact match 116 If a test does not match any list entry, it is skipped unless some list entry starts with ~ 117 */ 118 static bool ShouldSkip(const SkTDArray<const char*>& strings, const char* name); 119 120 /** 121 * Custom class for holding the arguments for a string flag. 122 * Publicly only has accessors so the strings cannot be modified. 123 */ 124 class StringArray { 125 public: 126 const char* operator[](int i) const { 127 SkASSERT(i >= 0 && i < fStrings.count()); 128 return fStrings[i].c_str(); 129 } 130 131 int count() const { 132 return fStrings.count(); 133 } 134 135 bool isEmpty() const { return this->count() == 0; } 136 137 private: 138 void reset() { fStrings.reset(); } 139 140 void append(const char* string) { 141 fStrings.push_back().set(string); 142 } 143 144 void append(const char* string, size_t length) { 145 fStrings.push_back().set(string, length); 146 } 147 148 SkTArray<SkString> fStrings; 149 150 friend class SkFlagInfo; 151 }; 152 153 private: 154 static SkFlagInfo* gHead; 155 static SkString gUsage; 156 157 // For access to gHead. 158 friend class SkFlagInfo; 159 }; 160 161 #define TO_STRING2(s) #s 162 #define TO_STRING(s) TO_STRING2(s) 163 164 #define DEFINE_bool(name, defaultValue, helpString) \ 165 bool FLAGS_##name; \ 166 static bool unused_##name = SkFlagInfo::CreateBoolFlag(TO_STRING(name), \ 167 NULL, \ 168 &FLAGS_##name, \ 169 defaultValue, \ 170 helpString) 171 172 // bool 2 allows specifying a short name. No check is done to ensure that shortName 173 // is actually shorter than name. 174 #define DEFINE_bool2(name, shortName, defaultValue, helpString) \ 175 bool FLAGS_##name; \ 176 static bool unused_##name = SkFlagInfo::CreateBoolFlag(TO_STRING(name), \ 177 TO_STRING(shortName),\ 178 &FLAGS_##name, \ 179 defaultValue, \ 180 helpString) 181 182 #define DECLARE_bool(name) extern bool FLAGS_##name; 183 184 #define DEFINE_string(name, defaultValue, helpString) \ 185 SkCommandLineFlags::StringArray FLAGS_##name; \ 186 static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \ 187 NULL, \ 188 &FLAGS_##name, \ 189 defaultValue, \ 190 helpString) 191 192 // string2 allows specifying a short name. There is an assert that shortName 193 // is only 1 character. 194 #define DEFINE_string2(name, shortName, defaultValue, helpString) \ 195 SkCommandLineFlags::StringArray FLAGS_##name; \ 196 static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \ 197 TO_STRING(shortName), \ 198 &FLAGS_##name, \ 199 defaultValue, \ 200 helpString) 201 202 #define DECLARE_string(name) extern SkCommandLineFlags::StringArray FLAGS_##name; 203 204 #define DEFINE_int32(name, defaultValue, helpString) \ 205 int32_t FLAGS_##name; \ 206 static bool unused_##name = SkFlagInfo::CreateIntFlag(TO_STRING(name), \ 207 &FLAGS_##name, \ 208 defaultValue, \ 209 helpString) 210 211 #define DECLARE_int32(name) extern int32_t FLAGS_##name; 212 213 #define DEFINE_double(name, defaultValue, helpString) \ 214 double FLAGS_##name; \ 215 static bool unused_##name = SkFlagInfo::CreateDoubleFlag(TO_STRING(name), \ 216 &FLAGS_##name, \ 217 defaultValue, \ 218 helpString) 219 220 #define DECLARE_double(name) extern double FLAGS_##name; 221 222 class SkFlagInfo { 223 224 public: 225 enum FlagTypes { 226 kBool_FlagType, 227 kString_FlagType, 228 kInt_FlagType, 229 kDouble_FlagType, 230 }; 231 232 /** 233 * Each Create<Type>Flag function creates an SkFlagInfo of the specified type. The SkFlagInfo 234 * object is appended to a list, which is deleted when SkCommandLineFlags::Parse is called. 235 * Therefore, each call should be made before the call to ::Parse. They are not intended 236 * to be called directly. Instead, use the macros described above. 237 * @param name Long version (at least 2 characters) of the name of the flag. This name can 238 * be referenced on the command line as "--name" to set the value of this flag. 239 * @param shortName Short version (one character) of the name of the flag. This name can 240 * be referenced on the command line as "-shortName" to set the value of this flag. 241 * @param p<Type> Pointer to a global variable which holds the value set by SkCommandLineFlags. 242 * @param defaultValue The default value of this flag. The variable pointed to by p<Type> will 243 * be set to this value initially. This is also displayed as part of the help output. 244 * @param helpString Explanation of what this flag changes in the program. 245 */ 246 static bool CreateBoolFlag(const char* name, const char* shortName, bool* pBool, 247 bool defaultValue, const char* helpString) { 248 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, shortName, kBool_FlagType, helpString)); 249 info->fBoolValue = pBool; 250 *info->fBoolValue = info->fDefaultBool = defaultValue; 251 return true; 252 } 253 254 /** 255 * See comments for CreateBoolFlag. 256 * @param pStrings Unlike the others, this is a pointer to an array of values. 257 * @param defaultValue Thise default will be parsed so that strings separated by spaces 258 * will be added to pStrings. 259 */ 260 static bool CreateStringFlag(const char* name, const char* shortName, 261 SkCommandLineFlags::StringArray* pStrings, 262 const char* defaultValue, const char* helpString); 263 264 /** 265 * See comments for CreateBoolFlag. 266 */ 267 static bool CreateIntFlag(const char* name, int32_t* pInt, 268 int32_t defaultValue, const char* helpString) { 269 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, NULL, kInt_FlagType, helpString)); 270 info->fIntValue = pInt; 271 *info->fIntValue = info->fDefaultInt = defaultValue; 272 return true; 273 } 274 275 /** 276 * See comments for CreateBoolFlag. 277 */ 278 static bool CreateDoubleFlag(const char* name, double* pDouble, 279 double defaultValue, const char* helpString) { 280 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, NULL, kDouble_FlagType, helpString)); 281 info->fDoubleValue = pDouble; 282 *info->fDoubleValue = info->fDefaultDouble = defaultValue; 283 return true; 284 } 285 286 /** 287 * Returns true if the string matches this flag. 288 * For a boolean flag, also sets the value, since a boolean flag can be set in a number of ways 289 * without looking at the following string: 290 * --name 291 * --noname 292 * --name=true 293 * --name=false 294 * --name=1 295 * --name=0 296 * --name=TRUE 297 * --name=FALSE 298 */ 299 bool match(const char* string); 300 301 FlagTypes getFlagType() const { return fFlagType; } 302 303 void resetStrings() { 304 if (kString_FlagType == fFlagType) { 305 fStrings->reset(); 306 } else { 307 SkASSERT(!"Can only call resetStrings on kString_FlagType"); 308 } 309 } 310 311 void append(const char* string) { 312 if (kString_FlagType == fFlagType) { 313 fStrings->append(string); 314 } else { 315 SkASSERT(!"Can only append to kString_FlagType"); 316 } 317 } 318 319 void setInt(int32_t value) { 320 if (kInt_FlagType == fFlagType) { 321 *fIntValue = value; 322 } else { 323 SkASSERT(!"Can only call setInt on kInt_FlagType"); 324 } 325 } 326 327 void setDouble(double value) { 328 if (kDouble_FlagType == fFlagType) { 329 *fDoubleValue = value; 330 } else { 331 SkASSERT(!"Can only call setDouble on kDouble_FlagType"); 332 } 333 } 334 335 void setBool(bool value) { 336 if (kBool_FlagType == fFlagType) { 337 *fBoolValue = value; 338 } else { 339 SkASSERT(!"Can only call setBool on kBool_FlagType"); 340 } 341 } 342 343 SkFlagInfo* next() { return fNext; } 344 345 const SkString& name() const { return fName; } 346 347 const SkString& shortName() const { return fShortName; } 348 349 const SkString& help() const { return fHelpString; } 350 351 SkString defaultValue() const { 352 SkString result; 353 switch (fFlagType) { 354 case SkFlagInfo::kBool_FlagType: 355 result.printf("%s", fDefaultBool ? "true" : "false"); 356 break; 357 case SkFlagInfo::kString_FlagType: 358 return fDefaultString; 359 case SkFlagInfo::kInt_FlagType: 360 result.printf("%i", fDefaultInt); 361 break; 362 case SkFlagInfo::kDouble_FlagType: 363 result.printf("%2.2f", fDefaultDouble); 364 break; 365 default: 366 SkASSERT(!"Invalid flag type"); 367 } 368 return result; 369 } 370 371 SkString typeAsString() const { 372 switch (fFlagType) { 373 case SkFlagInfo::kBool_FlagType: 374 return SkString("bool"); 375 case SkFlagInfo::kString_FlagType: 376 return SkString("string"); 377 case SkFlagInfo::kInt_FlagType: 378 return SkString("int"); 379 case SkFlagInfo::kDouble_FlagType: 380 return SkString("double"); 381 default: 382 SkASSERT(!"Invalid flag type"); 383 return SkString(); 384 } 385 } 386 387 private: 388 SkFlagInfo(const char* name, const char* shortName, FlagTypes type, const char* helpString) 389 : fName(name) 390 , fShortName(shortName) 391 , fFlagType(type) 392 , fHelpString(helpString) 393 , fBoolValue(NULL) 394 , fDefaultBool(false) 395 , fIntValue(NULL) 396 , fDefaultInt(0) 397 , fDoubleValue(NULL) 398 , fDefaultDouble(0) 399 , fStrings(NULL) { 400 fNext = SkCommandLineFlags::gHead; 401 SkCommandLineFlags::gHead = this; 402 SkASSERT(NULL != name && strlen(name) > 1); 403 SkASSERT(NULL == shortName || 1 == strlen(shortName)); 404 } 405 406 /** 407 * Set a StringArray to hold the values stored in defaultStrings. 408 * @param array The StringArray to modify. 409 * @param defaultStrings Space separated list of strings that should be inserted into array 410 * individually. 411 */ 412 static void SetDefaultStrings(SkCommandLineFlags::StringArray* array, 413 const char* defaultStrings); 414 415 // Name of the flag, without initial dashes 416 SkString fName; 417 SkString fShortName; 418 FlagTypes fFlagType; 419 SkString fHelpString; 420 bool* fBoolValue; 421 bool fDefaultBool; 422 int32_t* fIntValue; 423 int32_t fDefaultInt; 424 double* fDoubleValue; 425 double fDefaultDouble; 426 SkCommandLineFlags::StringArray* fStrings; 427 // Both for the help string and in case fStrings is empty. 428 SkString fDefaultString; 429 430 // In order to keep a linked list. 431 SkFlagInfo* fNext; 432 }; 433 #endif // SK_COMMAND_LINE_FLAGS_H 434
