include/llvm/Support/Path.h

   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;  ///< The iterators current position within Path.
  58   Style S;             ///< 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;  ///< The iterators current position within Path.
  84   Style S;             ///< 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 /// @code
 125 ///   directory/filename.cpp => directory/
 126 ///   directory/             => directory
 127 ///   filename.cpp           => <empty>
 128 ///   /                      => /
 129 /// @endcode
 130 ///
 131 /// @param path A path that is modified to not have a file component.
 132 void remove_filename(SmallVectorImpl<char> &path, Style style = Style::native);
 133
 134 /// Replace the file extension of \a path with \a extension.
 135 ///
 136 /// @code
 137 ///   ./filename.cpp => ./filename.extension
 138 ///   ./filename     => ./filename.extension
 139 ///   ./             => ./.extension
 140 /// @endcode
 141 ///
 142 /// @param path A path that has its extension replaced with \a extension.
 143 /// @param extension The extension to be added. It may be empty. It may also
 144 ///                  optionally start with a '.', if it does not, one will be
 145 ///                  prepended.
 146 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,
 147                        Style style = Style::native);
 148
 149 /// Replace matching path prefix with another path.
 150 ///
 151 /// @code
 152 ///   /foo, /old, /new => /foo
 153 ///   /old/foo, /old, /new => /new/foo
 154 ///   /foo, <empty>, /new => /new/foo
 155 ///   /old/foo, /old, <empty> => /foo
 156 /// @endcode
 157 ///
 158 /// @param Path If \a Path starts with \a OldPrefix modify to instead
 159 ///        start with \a NewPrefix.
 160 /// @param OldPrefix The path prefix to strip from \a Path.
 161 /// @param NewPrefix The path prefix to replace \a NewPrefix with.
 162 void replace_path_prefix(SmallVectorImpl<char> &Path,
 163                          const StringRef &OldPrefix, const StringRef &NewPrefix,
 164                          Style style = Style::native);
 165
 166 /// Append to path.
 167 ///
 168 /// @code
 169 ///   /foo  + bar/f => /foo/bar/f
 170 ///   /foo/ + bar/f => /foo/bar/f
 171 ///   foo   + bar/f => foo/bar/f
 172 /// @endcode
 173 ///
 174 /// @param path Set to \a path + \a component.
 175 /// @param a The component to be appended to \a path.
 176 void append(SmallVectorImpl<char> &path, const Twine &a,
 177                                          const Twine &b = "",
 178                                          const Twine &c = "",
 179                                          const Twine &d = "");
 180
 181 void append(SmallVectorImpl<char> &path, Style style, const Twine &a,
 182             const Twine &b = "", const Twine &c = "", const Twine &d = "");
 183
 184 /// Append to path.
 185 ///
 186 /// @code
 187 ///   /foo  + [bar,f] => /foo/bar/f
 188 ///   /foo/ + [bar,f] => /foo/bar/f
 189 ///   foo   + [bar,f] => foo/bar/f
 190 /// @endcode
 191 ///
 192 /// @param path Set to \a path + [\a begin, \a end).
 193 /// @param begin Start of components to append.
 194 /// @param end One past the end of components to append.
 195 void append(SmallVectorImpl<char> &path, const_iterator begin,
 196             const_iterator end, Style style = Style::native);
 197
 198 /// @}
 199 /// @name Transforms (or some other better name)
 200 /// @{
 201
 202 /// Convert path to the native form. This is used to give paths to users and
 203 /// operating system calls in the platform's normal way. For example, on Windows
 204 /// all '/' are converted to '\'.
 205 ///
 206 /// @param path A path that is transformed to native format.
 207 /// @param result Holds the result of the transformation.
 208 void native(const Twine &path, SmallVectorImpl<char> &result,
 209             Style style = Style::native);
 210
 211 /// Convert path to the native form in place. This is used to give paths to
 212 /// users and operating system calls in the platform's normal way. For example,
 213 /// on Windows all '/' are converted to '\'.
 214 ///
 215 /// @param path A path that is transformed to native format.
 216 void native(SmallVectorImpl<char> &path, Style style = Style::native);
 217
 218 /// Replaces backslashes with slashes if Windows.
 219 ///
 220 /// @param path processed path
 221 /// @result The result of replacing backslashes with forward slashes if Windows.
 222 /// On Unix, this function is a no-op because backslashes are valid path
 223 /// chracters.
 224 std::string convert_to_slash(StringRef path, Style style = Style::native);
 225
 226 /// @}
 227 /// @name Lexical Observers
 228 /// @{
 229
 230 /// Get root name.
 231 ///
 232 /// @code
 233 ///   //net/hello => //net
 234 ///   c:/hello    => c: (on Windows, on other platforms nothing)
 235 ///   /hello      => <empty>
 236 /// @endcode
 237 ///
 238 /// @param path Input path.
 239 /// @result The root name of \a path if it has one, otherwise "".
 240 StringRef root_name(StringRef path, Style style = Style::native);
 241
 242 /// Get root directory.
 243 ///
 244 /// @code
 245 ///   /goo/hello => /
 246 ///   c:/hello   => /
 247 ///   d/file.txt => <empty>
 248 /// @endcode
 249 ///
 250 /// @param path Input path.
 251 /// @result The root directory of \a path if it has one, otherwise
 252 ///               "".
 253 StringRef root_directory(StringRef path, Style style = Style::native);
 254
 255 /// Get root path.
 256 ///
 257 /// Equivalent to root_name + root_directory.
 258 ///
 259 /// @param path Input path.
 260 /// @result The root path of \a path if it has one, otherwise "".
 261 StringRef root_path(StringRef path, Style style = Style::native);
 262
 263 /// Get relative path.
 264 ///
 265 /// @code
 266 ///   C:\hello\world => hello\world
 267 ///   foo/bar        => foo/bar
 268 ///   /foo/bar       => foo/bar
 269 /// @endcode
 270 ///
 271 /// @param path Input path.
 272 /// @result The path starting after root_path if one exists, otherwise "".
 273 StringRef relative_path(StringRef path, Style style = Style::native);
 274
 275 /// Get parent path.
 276 ///
 277 /// @code
 278 ///   /          => <empty>
 279 ///   /foo       => /
 280 ///   foo/../bar => foo/..
 281 /// @endcode
 282 ///
 283 /// @param path Input path.
 284 /// @result The parent path of \a path if one exists, otherwise "".
 285 StringRef parent_path(StringRef path, Style style = Style::native);
 286
 287 /// Get filename.
 288 ///
 289 /// @code
 290 ///   /foo.txt    => foo.txt
 291 ///   .          => .
 292 ///   ..         => ..
 293 ///   /          => /
 294 /// @endcode
 295 ///
 296 /// @param path Input path.
 297 /// @result The filename part of \a path. This is defined as the last component
 298 ///         of \a path.
 299 StringRef filename(StringRef path, Style style = Style::native);
 300
 301 /// Get stem.
 302 ///
 303 /// If filename contains a dot but not solely one or two dots, result is the
 304 /// substring of filename ending at (but not including) the last dot. Otherwise
 305 /// it is filename.
 306 ///
 307 /// @code
 308 ///   /foo/bar.txt => bar
 309 ///   /foo/bar     => bar
 310 ///   /foo/.txt    => <empty>
 311 ///   /foo/.       => .
 312 ///   /foo/..      => ..
 313 /// @endcode
 314 ///
 315 /// @param path Input path.
 316 /// @result The stem of \a path.
 317 StringRef stem(StringRef path, Style style = Style::native);
 318
 319 /// Get extension.
 320 ///
 321 /// If filename contains a dot but not solely one or two dots, result is the
 322 /// substring of filename starting at (and including) the last dot, and ending
 323 /// at the end of \a path. Otherwise "".
 324 ///
 325 /// @code
 326 ///   /foo/bar.txt => .txt
 327 ///   /foo/bar     => <empty>
 328 ///   /foo/.txt    => .txt
 329 /// @endcode
 330 ///
 331 /// @param path Input path.
 332 /// @result The extension of \a path.
 333 StringRef extension(StringRef path, Style style = Style::native);
 334
 335 /// Check whether the given char is a path separator on the host OS.
 336 ///
 337 /// @param value a character
 338 /// @result true if \a value is a path separator character on the host OS
 339 bool is_separator(char value, Style style = Style::native);
 340
 341 /// Return the preferred separator for this platform.
 342 ///
 343 /// @result StringRef of the preferred separator, null-terminated.
 344 StringRef get_separator(Style style = Style::native);
 345
 346 /// Get the typical temporary directory for the system, e.g.,
 347 /// "/var/tmp" or "C:/TEMP"
 348 ///
 349 /// @param erasedOnReboot Whether to favor a path that is erased on reboot
 350 /// rather than one that potentially persists longer. This parameter will be
 351 /// ignored if the user or system has set the typical environment variable
 352 /// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
 353 ///
 354 /// @param result Holds the resulting path name.
 355 void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
 356
 357 /// Get the user's home directory.
 358 ///
 359 /// @param result Holds the resulting path name.
 360 /// @result True if a home directory is set, false otherwise.
 361 bool home_directory(SmallVectorImpl<char> &result);
 362
 363 /// Has root name?
 364 ///
 365 /// root_name != ""
 366 ///
 367 /// @param path Input path.
 368 /// @result True if the path has a root name, false otherwise.
 369 bool has_root_name(const Twine &path, Style style = Style::native);
 370
 371 /// Has root directory?
 372 ///
 373 /// root_directory != ""
 374 ///
 375 /// @param path Input path.
 376 /// @result True if the path has a root directory, false otherwise.
 377 bool has_root_directory(const Twine &path, Style style = Style::native);
 378
 379 /// Has root path?
 380 ///
 381 /// root_path != ""
 382 ///
 383 /// @param path Input path.
 384 /// @result True if the path has a root path, false otherwise.
 385 bool has_root_path(const Twine &path, Style style = Style::native);
 386
 387 /// Has relative path?
 388 ///
 389 /// relative_path != ""
 390 ///
 391 /// @param path Input path.
 392 /// @result True if the path has a relative path, false otherwise.
 393 bool has_relative_path(const Twine &path, Style style = Style::native);
 394
 395 /// Has parent path?
 396 ///
 397 /// parent_path != ""
 398 ///
 399 /// @param path Input path.
 400 /// @result True if the path has a parent path, false otherwise.
 401 bool has_parent_path(const Twine &path, Style style = Style::native);
 402
 403 /// Has filename?
 404 ///
 405 /// filename != ""
 406 ///
 407 /// @param path Input path.
 408 /// @result True if the path has a filename, false otherwise.
 409 bool has_filename(const Twine &path, Style style = Style::native);
 410
 411 /// Has stem?
 412 ///
 413 /// stem != ""
 414 ///
 415 /// @param path Input path.
 416 /// @result True if the path has a stem, false otherwise.
 417 bool has_stem(const Twine &path, Style style = Style::native);
 418
 419 /// Has extension?
 420 ///
 421 /// extension != ""
 422 ///
 423 /// @param path Input path.
 424 /// @result True if the path has a extension, false otherwise.
 425 bool has_extension(const Twine &path, Style style = Style::native);
 426
 427 /// Is path absolute?
 428 ///
 429 /// @param path Input path.
 430 /// @result True if the path is absolute, false if it is not.
 431 bool is_absolute(const Twine &path, Style style = Style::native);
 432
 433 /// Is path relative?
 434 ///
 435 /// @param path Input path.
 436 /// @result True if the path is relative, false if it is not.
 437 bool is_relative(const Twine &path, Style style = Style::native);
 438
 439 /// Remove redundant leading "./" pieces and consecutive separators.
 440 ///
 441 /// @param path Input path.
 442 /// @result The cleaned-up \a path.
 443 StringRef remove_leading_dotslash(StringRef path, Style style = Style::native);
 444
 445 /// In-place remove any './' and optionally '../' components from a path.
 446 ///
 447 /// @param path processed path
 448 /// @param remove_dot_dot specify if '../' (except for leading "../") should be
 449 /// removed
 450 /// @result True if path was changed
 451 bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot = false,
 452                  Style style = Style::native);
 453
 454 #if defined(_WIN32)
 455 std::error_code widenPath(const Twine &Path8, SmallVectorImpl<wchar_t> &Path16);
 456 #endif
 457
 458 } // end namespace path
 459 } // end namespace sys
 460 } // end namespace llvm
 461
 462 #endif