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 /** 112 * Custom class for holding the arguments for a string flag. 113 * Publicly only has accessors so the strings cannot be modified. 114 */ 115 class StringArray { 116 public: 117 const char* operator[](int i) const { 118 SkASSERT(i >= 0 && i < fStrings.count()); 119 return fStrings[i].c_str(); 120 } 121 122 int count() const { 123 return fStrings.count(); 124 } 125 126 bool isEmpty() const { return this->count() == 0; } 127 128 /** 129 * Returns true iff string is equal to one of the strings in this array. 130 */ 131 bool contains(const char* string) const { 132 for (int i = 0; i < fStrings.count(); i++) { 133 if (fStrings[i].equals(string)) { 134 return true; 135 } 136 } 137 return false; 138 } 139 140 private: 141 void reset() { fStrings.reset(); } 142 143 void append(const char* string) { 144 fStrings.push_back().set(string); 145 } 146 147 void append(const char* string, size_t length) { 148 fStrings.push_back().set(string, length); 149 } 150 151 SkTArray<SkString> fStrings; 152 153 friend class SkFlagInfo; 154 }; 155 156 /* Takes a list of the form [~][^]match[$] 157 ~ causes a matching test to always be skipped 158 ^ requires the start of the test to match 159 $ requires the end of the test to match 160 ^ and $ requires an exact match 161 If a test does not match any list entry, it is skipped unless some list entry starts with ~ 162 */ 163 static bool ShouldSkip(const SkTDArray<const char*>& strings, const char* name); 164 static bool ShouldSkip(const StringArray& strings, const char* name); 165 166 private: 167 static SkFlagInfo* gHead; 168 static SkString gUsage; 169 170 // For access to gHead. 171 friend class SkFlagInfo; 172 }; 173 174 #define TO_STRING2(s) #s 175 #define TO_STRING(s) TO_STRING2(s) 176 177 #define DEFINE_bool(name, defaultValue, helpString) \ 178 bool FLAGS_##name; \ 179 static bool unused_##name = SkFlagInfo::CreateBoolFlag(TO_STRING(name), \ 180 NULL, \ 181 &FLAGS_##name, \ 182 defaultValue, \ 183 helpString) 184 185 // bool 2 allows specifying a short name. No check is done to ensure that shortName 186 // is actually shorter than name. 187 #define DEFINE_bool2(name, shortName, defaultValue, helpString) \ 188 bool FLAGS_##name; \ 189 static bool unused_##name = SkFlagInfo::CreateBoolFlag(TO_STRING(name), \ 190 TO_STRING(shortName),\ 191 &FLAGS_##name, \ 192 defaultValue, \ 193 helpString) 194 195 #define DECLARE_bool(name) extern bool FLAGS_##name; 196 197 #define DEFINE_string(name, defaultValue, helpString) \ 198 SkCommandLineFlags::StringArray FLAGS_##name; \ 199 static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \ 200 NULL, \ 201 &FLAGS_##name, \ 202 defaultValue, \ 203 helpString) 204 205 // string2 allows specifying a short name. There is an assert that shortName 206 // is only 1 character. 207 #define DEFINE_string2(name, shortName, defaultValue, helpString) \ 208 SkCommandLineFlags::StringArray FLAGS_##name; \ 209 static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name), \ 210 TO_STRING(shortName), \ 211 &FLAGS_##name, \ 212 defaultValue, \ 213 helpString) 214 215 #define DECLARE_string(name) extern SkCommandLineFlags::StringArray FLAGS_##name; 216 217 #define DEFINE_int32(name, defaultValue, helpString) \ 218 int32_t FLAGS_##name; \ 219 static bool unused_##name = SkFlagInfo::CreateIntFlag(TO_STRING(name), \ 220 &FLAGS_##name, \ 221 defaultValue, \ 222 helpString) 223 224 #define DECLARE_int32(name) extern int32_t FLAGS_##name; 225 226 #define DEFINE_double(name, defaultValue, helpString) \ 227 double FLAGS_##name; \ 228 static bool unused_##name = SkFlagInfo::CreateDoubleFlag(TO_STRING(name), \ 229 &FLAGS_##name, \ 230 defaultValue, \ 231 helpString) 232 233 #define DECLARE_double(name) extern double FLAGS_##name; 234 235 class SkFlagInfo { 236 237 public: 238 enum FlagTypes { 239 kBool_FlagType, 240 kString_FlagType, 241 kInt_FlagType, 242 kDouble_FlagType, 243 }; 244 245 /** 246 * Each Create<Type>Flag function creates an SkFlagInfo of the specified type. The SkFlagInfo 247 * object is appended to a list, which is deleted when SkCommandLineFlags::Parse is called. 248 * Therefore, each call should be made before the call to ::Parse. They are not intended 249 * to be called directly. Instead, use the macros described above. 250 * @param name Long version (at least 2 characters) of the name of the flag. This name can 251 * be referenced on the command line as "--name" to set the value of this flag. 252 * @param shortName Short version (one character) of the name of the flag. This name can 253 * be referenced on the command line as "-shortName" to set the value of this flag. 254 * @param p<Type> Pointer to a global variable which holds the value set by SkCommandLineFlags. 255 * @param defaultValue The default value of this flag. The variable pointed to by p<Type> will 256 * be set to this value initially. This is also displayed as part of the help output. 257 * @param helpString Explanation of what this flag changes in the program. 258 */ 259 static bool CreateBoolFlag(const char* name, const char* shortName, bool* pBool, 260 bool defaultValue, const char* helpString) { 261 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, shortName, kBool_FlagType, helpString)); 262 info->fBoolValue = pBool; 263 *info->fBoolValue = info->fDefaultBool = defaultValue; 264 return true; 265 } 266 267 /** 268 * See comments for CreateBoolFlag. 269 * @param pStrings Unlike the others, this is a pointer to an array of values. 270 * @param defaultValue Thise default will be parsed so that strings separated by spaces 271 * will be added to pStrings. 272 */ 273 static bool CreateStringFlag(const char* name, const char* shortName, 274 SkCommandLineFlags::StringArray* pStrings, 275 const char* defaultValue, const char* helpString); 276 277 /** 278 * See comments for CreateBoolFlag. 279 */ 280 static bool CreateIntFlag(const char* name, int32_t* pInt, 281 int32_t defaultValue, const char* helpString) { 282 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, NULL, kInt_FlagType, helpString)); 283 info->fIntValue = pInt; 284 *info->fIntValue = info->fDefaultInt = defaultValue; 285 return true; 286 } 287 288 /** 289 * See comments for CreateBoolFlag. 290 */ 291 static bool CreateDoubleFlag(const char* name, double* pDouble, 292 double defaultValue, const char* helpString) { 293 SkFlagInfo* info = SkNEW_ARGS(SkFlagInfo, (name, NULL, kDouble_FlagType, helpString)); 294 info->fDoubleValue = pDouble; 295 *info->fDoubleValue = info->fDefaultDouble = defaultValue; 296 return true; 297 } 298 299 /** 300 * Returns true if the string matches this flag. 301 * For a boolean flag, also sets the value, since a boolean flag can be set in a number of ways 302 * without looking at the following string: 303 * --name 304 * --noname 305 * --name=true 306 * --name=false 307 * --name=1 308 * --name=0 309 * --name=TRUE 310 * --name=FALSE 311 */ 312 bool match(const char* string); 313 314 FlagTypes getFlagType() const { return fFlagType; } 315 316 void resetStrings() { 317 if (kString_FlagType == fFlagType) { 318 fStrings->reset(); 319 } else { 320 SkDEBUGFAIL("Can only call resetStrings on kString_FlagType"); 321 } 322 } 323 324 void append(const char* string) { 325 if (kString_FlagType == fFlagType) { 326 fStrings->append(string); 327 } else { 328 SkDEBUGFAIL("Can only append to kString_FlagType"); 329 } 330 } 331 332 void setInt(int32_t value) { 333 if (kInt_FlagType == fFlagType) { 334 *fIntValue = value; 335 } else { 336 SkDEBUGFAIL("Can only call setInt on kInt_FlagType"); 337 } 338 } 339 340 void setDouble(double value) { 341 if (kDouble_FlagType == fFlagType) { 342 *fDoubleValue = value; 343 } else { 344 SkDEBUGFAIL("Can only call setDouble on kDouble_FlagType"); 345 } 346 } 347 348 void setBool(bool value) { 349 if (kBool_FlagType == fFlagType) { 350 *fBoolValue = value; 351 } else { 352 SkDEBUGFAIL("Can only call setBool on kBool_FlagType"); 353 } 354 } 355 356 SkFlagInfo* next() { return fNext; } 357 358 const SkString& name() const { return fName; } 359 360 const SkString& shortName() const { return fShortName; } 361 362 const SkString& help() const { return fHelpString; } 363 364 SkString defaultValue() const { 365 SkString result; 366 switch (fFlagType) { 367 case SkFlagInfo::kBool_FlagType: 368 result.printf("%s", fDefaultBool ? "true" : "false"); 369 break; 370 case SkFlagInfo::kString_FlagType: 371 return fDefaultString; 372 case SkFlagInfo::kInt_FlagType: 373 result.printf("%i", fDefaultInt); 374 break; 375 case SkFlagInfo::kDouble_FlagType: 376 result.printf("%2.2f", fDefaultDouble); 377 break; 378 default: 379 SkDEBUGFAIL("Invalid flag type"); 380 } 381 return result; 382 } 383 384 SkString typeAsString() const { 385 switch (fFlagType) { 386 case SkFlagInfo::kBool_FlagType: 387 return SkString("bool"); 388 case SkFlagInfo::kString_FlagType: 389 return SkString("string"); 390 case SkFlagInfo::kInt_FlagType: 391 return SkString("int"); 392 case SkFlagInfo::kDouble_FlagType: 393 return SkString("double"); 394 default: 395 SkDEBUGFAIL("Invalid flag type"); 396 return SkString(); 397 } 398 } 399 400 private: 401 SkFlagInfo(const char* name, const char* shortName, FlagTypes type, const char* helpString) 402 : fName(name) 403 , fShortName(shortName) 404 , fFlagType(type) 405 , fHelpString(helpString) 406 , fBoolValue(NULL) 407 , fDefaultBool(false) 408 , fIntValue(NULL) 409 , fDefaultInt(0) 410 , fDoubleValue(NULL) 411 , fDefaultDouble(0) 412 , fStrings(NULL) { 413 fNext = SkCommandLineFlags::gHead; 414 SkCommandLineFlags::gHead = this; 415 SkASSERT(NULL != name && strlen(name) > 1); 416 SkASSERT(NULL == shortName || 1 == strlen(shortName)); 417 } 418 419 /** 420 * Set a StringArray to hold the values stored in defaultStrings. 421 * @param array The StringArray to modify. 422 * @param defaultStrings Space separated list of strings that should be inserted into array 423 * individually. 424 */ 425 static void SetDefaultStrings(SkCommandLineFlags::StringArray* array, 426 const char* defaultStrings); 427 428 // Name of the flag, without initial dashes 429 SkString fName; 430 SkString fShortName; 431 FlagTypes fFlagType; 432 SkString fHelpString; 433 bool* fBoolValue; 434 bool fDefaultBool; 435 int32_t* fIntValue; 436 int32_t fDefaultInt; 437 double* fDoubleValue; 438 double fDefaultDouble; 439 SkCommandLineFlags::StringArray* fStrings; 440 // Both for the help string and in case fStrings is empty. 441 SkString fDefaultString; 442 443 // In order to keep a linked list. 444 SkFlagInfo* fNext; 445 }; 446 #endif // SK_COMMAND_LINE_FLAGS_H 447
