1 //===- llvm/Support/Path.h - Path Operating System Concept ------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file declares the llvm::sys::path namespace. It is designed after 10 // TR2/boost filesystem (v3), but modified to remove exception handling and the 11 // path class. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_SUPPORT_PATH_H 16 #define LLVM_SUPPORT_PATH_H 17 18 #include "llvm/ADT/Twine.h" 19 #include "llvm/ADT/iterator.h" 20 #include "llvm/Support/DataTypes.h" 21 #include <iterator> 22 #include <system_error> 23 24 namespace llvm { 25 namespace sys { 26 namespace path { 27 28 enum class Style { windows, posix, native }; 29 30 /// @name Lexical Component Iterator 31 /// @{ 32 33 /// Path iterator. 34 /// 35 /// This is an input iterator that iterates over the individual components in 36 /// \a path. The traversal order is as follows: 37 /// * The root-name element, if present. 38 /// * The root-directory element, if present. 39 /// * Each successive filename element, if present. 40 /// * Dot, if one or more trailing non-root slash characters are present. 41 /// Traversing backwards is possible with \a reverse_iterator 42 /// 43 /// Iteration examples. Each component is separated by ',': 44 /// @code 45 /// / => / 46 /// /foo => /,foo 47 /// foo/ => foo,. 48 /// /foo/bar => /,foo,bar 49 /// ../ => ..,. 50 /// C:\foo\bar => C:,/,foo,bar 51 /// @endcode 52 class const_iterator 53 : public iterator_facade_base<const_iterator, std::input_iterator_tag, 54 const StringRef> { 55 StringRef Path; ///< The entire path. 56 StringRef Component; ///< The current component. Not necessarily in Path. 57 size_t Position = 0; ///< The iterators current position within Path. 58 Style S = Style::native; ///< The path style to use. 59 60 // An end iterator has Position = Path.size() + 1. 61 friend const_iterator begin(StringRef path, Style style); 62 friend const_iterator end(StringRef path); 63 64 public: 65 reference operator*() const { return Component; } 66 const_iterator &operator++(); // preincrement 67 bool operator==(const const_iterator &RHS) const; 68 69 /// Difference in bytes between this and RHS. 70 ptrdiff_t operator-(const const_iterator &RHS) const; 71 }; 72 73 /// Reverse path iterator. 74 /// 75 /// This is an input iterator that iterates over the individual components in 76 /// \a path in reverse order. The traversal order is exactly reversed from that 77 /// of \a const_iterator 78 class reverse_iterator 79 : public iterator_facade_base<reverse_iterator, std::input_iterator_tag, 80 const StringRef> { 81 StringRef Path; ///< The entire path. 82 StringRef Component; ///< The current component. Not necessarily in Path. 83 size_t Position = 0; ///< The iterators current position within Path. 84 Style S = Style::native; ///< The path style to use. 85 86 friend reverse_iterator rbegin(StringRef path, Style style); 87 friend reverse_iterator rend(StringRef path); 88 89 public: 90 reference operator*() const { return Component; } 91 reverse_iterator &operator++(); // preincrement 92 bool operator==(const reverse_iterator &RHS) const; 93 94 /// Difference in bytes between this and RHS. 95 ptrdiff_t operator-(const reverse_iterator &RHS) const; 96 }; 97 98 /// Get begin iterator over \a path. 99 /// @param path Input path. 100 /// @returns Iterator initialized with the first component of \a path. 101 const_iterator begin(StringRef path, Style style = Style::native); 102 103 /// Get end iterator over \a path. 104 /// @param path Input path. 105 /// @returns Iterator initialized to the end of \a path. 106 const_iterator end(StringRef path); 107 108 /// Get reverse begin iterator over \a path. 109 /// @param path Input path. 110 /// @returns Iterator initialized with the first reverse component of \a path. 111 reverse_iterator rbegin(StringRef path, Style style = Style::native); 112 113 /// Get reverse end iterator over \a path. 114 /// @param path Input path. 115 /// @returns Iterator initialized to the reverse end of \a path. 116 reverse_iterator rend(StringRef path); 117 118 /// @} 119 /// @name Lexical Modifiers 120 /// @{ 121 122 /// Remove the last component from \a path unless it is the root dir. 123 /// 124 /// Similar to the POSIX "dirname" utility. 125 /// 126 /// @code 127 /// directory/filename.cpp => directory/ 128 /// directory/ => directory 129 /// filename.cpp => <empty> 130 /// / => / 131 /// @endcode 132 /// 133 /// @param path A path that is modified to not have a file component. 134 void remove_filename(SmallVectorImpl<char> &path, Style style = Style::native); 135 136 /// Replace the file extension of \a path with \a extension. 137 /// 138 /// @code 139 /// ./filename.cpp => ./filename.extension 140 /// ./filename => ./filename.extension 141 /// ./ => ./.extension 142 /// @endcode 143 /// 144 /// @param path A path that has its extension replaced with \a extension. 145 /// @param extension The extension to be added. It may be empty. It may also 146 /// optionally start with a '.', if it does not, one will be 147 /// prepended. 148 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension, 149 Style style = Style::native); 150 151 /// Replace matching path prefix with another path. 152 /// 153 /// @code 154 /// /foo, /old, /new => /foo 155 /// /old, /old, /new => /new 156 /// /old, /old/, /new, false => /old 157 /// /old, /old/, /new, true => /new 158 /// /old/foo, /old, /new => /new/foo 159 /// /old/foo, /old/, /new => /new/foo 160 /// /old/foo, /old/, /new/ => /new/foo 161 /// /oldfoo, /old, /new => /oldfoo 162 /// /foo, <empty>, /new => /new/foo 163 /// /foo, <empty>, new => new/foo 164 /// /old/foo, /old, <empty>, false => /foo 165 /// /old/foo, /old, <empty>, true => foo 166 /// @endcode 167 /// 168 /// @param Path If \a Path starts with \a OldPrefix modify to instead 169 /// start with \a NewPrefix. 170 /// @param OldPrefix The path prefix to strip from \a Path. Any trailing 171 /// path separator is ignored if strict is true. 172 /// @param NewPrefix The path prefix to replace \a NewPrefix with. 173 /// @param style The path separator style 174 /// @param strict If strict is true, a directory separator following 175 /// \a OldPrefix will also be stripped. Otherwise, directory 176 /// separators will only be matched and stripped when present 177 /// in \a OldPrefix. 178 /// @result true if \a Path begins with OldPrefix 179 bool replace_path_prefix(SmallVectorImpl<char> &Path, 180 const StringRef &OldPrefix, const StringRef &NewPrefix, 181 Style style = Style::native, bool strict = false); 182 183 /// Append to path. 184 /// 185 /// @code 186 /// /foo + bar/f => /foo/bar/f 187 /// /foo/ + bar/f => /foo/bar/f 188 /// foo + bar/f => foo/bar/f 189 /// @endcode 190 /// 191 /// @param path Set to \a path + \a component. 192 /// @param a The component to be appended to \a path. 193 void append(SmallVectorImpl<char> &path, const Twine &a, 194 const Twine &b = "", 195 const Twine &c = "", 196 const Twine &d = ""); 197 198 void append(SmallVectorImpl<char> &path, Style style, const Twine &a, 199 const Twine &b = "", const Twine &c = "", const Twine &d = ""); 200 201 /// Append to path. 202 /// 203 /// @code 204 /// /foo + [bar,f] => /foo/bar/f 205 /// /foo/ + [bar,f] => /foo/bar/f 206 /// foo + [bar,f] => foo/bar/f 207 /// @endcode 208 /// 209 /// @param path Set to \a path + [\a begin, \a end). 210 /// @param begin Start of components to append. 211 /// @param end One past the end of components to append. 212 void append(SmallVectorImpl<char> &path, const_iterator begin, 213 const_iterator end, Style style = Style::native); 214 215 /// @} 216 /// @name Transforms (or some other better name) 217 /// @{ 218 219 /// Convert path to the native form. This is used to give paths to users and 220 /// operating system calls in the platform's normal way. For example, on Windows 221 /// all '/' are converted to '\'. 222 /// 223 /// @param path A path that is transformed to native format. 224 /// @param result Holds the result of the transformation. 225 void native(const Twine &path, SmallVectorImpl<char> &result, 226 Style style = Style::native); 227 228 /// Convert path to the native form in place. This is used to give paths to 229 /// users and operating system calls in the platform's normal way. For example, 230 /// on Windows all '/' are converted to '\'. 231 /// 232 /// @param path A path that is transformed to native format. 233 void native(SmallVectorImpl<char> &path, Style style = Style::native); 234 235 /// Replaces backslashes with slashes if Windows. 236 /// 237 /// @param path processed path 238 /// @result The result of replacing backslashes with forward slashes if Windows. 239 /// On Unix, this function is a no-op because backslashes are valid path 240 /// chracters. 241 std::string convert_to_slash(StringRef path, Style style = Style::native); 242 243 /// @} 244 /// @name Lexical Observers 245 /// @{ 246 247 /// Get root name. 248 /// 249 /// @code 250 /// //net/hello => //net 251 /// c:/hello => c: (on Windows, on other platforms nothing) 252 /// /hello => <empty> 253 /// @endcode 254 /// 255 /// @param path Input path. 256 /// @result The root name of \a path if it has one, otherwise "". 257 StringRef root_name(StringRef path, Style style = Style::native); 258 259 /// Get root directory. 260 /// 261 /// @code 262 /// /goo/hello => / 263 /// c:/hello => / 264 /// d/file.txt => <empty> 265 /// @endcode 266 /// 267 /// @param path Input path. 268 /// @result The root directory of \a path if it has one, otherwise 269 /// "". 270 StringRef root_directory(StringRef path, Style style = Style::native); 271 272 /// Get root path. 273 /// 274 /// Equivalent to root_name + root_directory. 275 /// 276 /// @param path Input path. 277 /// @result The root path of \a path if it has one, otherwise "". 278 StringRef root_path(StringRef path, Style style = Style::native); 279 280 /// Get relative path. 281 /// 282 /// @code 283 /// C:\hello\world => hello\world 284 /// foo/bar => foo/bar 285 /// /foo/bar => foo/bar 286 /// @endcode 287 /// 288 /// @param path Input path. 289 /// @result The path starting after root_path if one exists, otherwise "". 290 StringRef relative_path(StringRef path, Style style = Style::native); 291 292 /// Get parent path. 293 /// 294 /// @code 295 /// / => <empty> 296 /// /foo => / 297 /// foo/../bar => foo/.. 298 /// @endcode 299 /// 300 /// @param path Input path. 301 /// @result The parent path of \a path if one exists, otherwise "". 302 StringRef parent_path(StringRef path, Style style = Style::native); 303 304 /// Get filename. 305 /// 306 /// @code 307 /// /foo.txt => foo.txt 308 /// . => . 309 /// .. => .. 310 /// / => / 311 /// @endcode 312 /// 313 /// @param path Input path. 314 /// @result The filename part of \a path. This is defined as the last component 315 /// of \a path. Similar to the POSIX "basename" utility. 316 StringRef filename(StringRef path, Style style = Style::native); 317 318 /// Get stem. 319 /// 320 /// If filename contains a dot but not solely one or two dots, result is the 321 /// substring of filename ending at (but not including) the last dot. Otherwise 322 /// it is filename. 323 /// 324 /// @code 325 /// /foo/bar.txt => bar 326 /// /foo/bar => bar 327 /// /foo/.txt => <empty> 328 /// /foo/. => . 329 /// /foo/.. => .. 330 /// @endcode 331 /// 332 /// @param path Input path. 333 /// @result The stem of \a path. 334 StringRef stem(StringRef path, Style style = Style::native); 335 336 /// Get extension. 337 /// 338 /// If filename contains a dot but not solely one or two dots, result is the 339 /// substring of filename starting at (and including) the last dot, and ending 340 /// at the end of \a path. Otherwise "". 341 /// 342 /// @code 343 /// /foo/bar.txt => .txt 344 /// /foo/bar => <empty> 345 /// /foo/.txt => .txt 346 /// @endcode 347 /// 348 /// @param path Input path. 349 /// @result The extension of \a path. 350 StringRef extension(StringRef path, Style style = Style::native); 351 352 /// Check whether the given char is a path separator on the host OS. 353 /// 354 /// @param value a character 355 /// @result true if \a value is a path separator character on the host OS 356 bool is_separator(char value, Style style = Style::native); 357 358 /// Return the preferred separator for this platform. 359 /// 360 /// @result StringRef of the preferred separator, null-terminated. 361 StringRef get_separator(Style style = Style::native); 362 363 /// Get the typical temporary directory for the system, e.g., 364 /// "/var/tmp" or "C:/TEMP" 365 /// 366 /// @param erasedOnReboot Whether to favor a path that is erased on reboot 367 /// rather than one that potentially persists longer. This parameter will be 368 /// ignored if the user or system has set the typical environment variable 369 /// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory. 370 /// 371 /// @param result Holds the resulting path name. 372 void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result); 373 374 /// Get the user's home directory. 375 /// 376 /// @param result Holds the resulting path name. 377 /// @result True if a home directory is set, false otherwise. 378 bool home_directory(SmallVectorImpl<char> &result); 379 380 /// Has root name? 381 /// 382 /// root_name != "" 383 /// 384 /// @param path Input path. 385 /// @result True if the path has a root name, false otherwise. 386 bool has_root_name(const Twine &path, Style style = Style::native); 387 388 /// Has root directory? 389 /// 390 /// root_directory != "" 391 /// 392 /// @param path Input path. 393 /// @result True if the path has a root directory, false otherwise. 394 bool has_root_directory(const Twine &path, Style style = Style::native); 395 396 /// Has root path? 397 /// 398 /// root_path != "" 399 /// 400 /// @param path Input path. 401 /// @result True if the path has a root path, false otherwise. 402 bool has_root_path(const Twine &path, Style style = Style::native); 403 404 /// Has relative path? 405 /// 406 /// relative_path != "" 407 /// 408 /// @param path Input path. 409 /// @result True if the path has a relative path, false otherwise. 410 bool has_relative_path(const Twine &path, Style style = Style::native); 411 412 /// Has parent path? 413 /// 414 /// parent_path != "" 415 /// 416 /// @param path Input path. 417 /// @result True if the path has a parent path, false otherwise. 418 bool has_parent_path(const Twine &path, Style style = Style::native); 419 420 /// Has filename? 421 /// 422 /// filename != "" 423 /// 424 /// @param path Input path. 425 /// @result True if the path has a filename, false otherwise. 426 bool has_filename(const Twine &path, Style style = Style::native); 427 428 /// Has stem? 429 /// 430 /// stem != "" 431 /// 432 /// @param path Input path. 433 /// @result True if the path has a stem, false otherwise. 434 bool has_stem(const Twine &path, Style style = Style::native); 435 436 /// Has extension? 437 /// 438 /// extension != "" 439 /// 440 /// @param path Input path. 441 /// @result True if the path has a extension, false otherwise. 442 bool has_extension(const Twine &path, Style style = Style::native); 443 444 /// Is path absolute? 445 /// 446 /// @param path Input path. 447 /// @result True if the path is absolute, false if it is not. 448 bool is_absolute(const Twine &path, Style style = Style::native); 449 450 /// Is path relative? 451 /// 452 /// @param path Input path. 453 /// @result True if the path is relative, false if it is not. 454 bool is_relative(const Twine &path, Style style = Style::native); 455 456 /// Remove redundant leading "./" pieces and consecutive separators. 457 /// 458 /// @param path Input path. 459 /// @result The cleaned-up \a path. 460 StringRef remove_leading_dotslash(StringRef path, Style style = Style::native); 461 462 /// In-place remove any './' and optionally '../' components from a path. 463 /// 464 /// @param path processed path 465 /// @param remove_dot_dot specify if '../' (except for leading "../") should be 466 /// removed 467 /// @result True if path was changed 468 bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot = false, 469 Style style = Style::native); 470 471 #if defined(_WIN32) 472 std::error_code widenPath(const Twine &Path8, SmallVectorImpl<wchar_t> &Path16); 473 #endif 474 475 } // end namespace path 476 } // end namespace sys 477 } // end namespace llvm 478 479 #endif 480