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 23namespace llvm { 24namespace sys { 25namespace path { 26 27enum class Style { 28 native, 29 posix, 30 windows_slash, 31 windows_backslash, 32 windows = windows_backslash, // deprecated 33}; 34 35/// Check if \p S uses POSIX path rules. 36constexpr bool is_style_posix(Style S) { 37 if (S == Style::posix) 38 return true; 39 if (S != Style::native) 40 return false; 41#if defined(_WIN32) 42 return false; 43#else 44 return true; 45#endif 46} 47 48/// Check if \p S uses Windows path rules. 49constexpr bool is_style_windows(Style S) { return !is_style_posix(S); } 50 51/// @name Lexical Component Iterator 52/// @{ 53 54/// Path iterator. 55/// 56/// This is an input iterator that iterates over the individual components in 57/// \a path. The traversal order is as follows: 58/// * The root-name element, if present. 59/// * The root-directory element, if present. 60/// * Each successive filename element, if present. 61/// * Dot, if one or more trailing non-root slash characters are present. 62/// Traversing backwards is possible with \a reverse_iterator 63/// 64/// Iteration examples. Each component is separated by ',': 65/// @code 66/// / => / 67/// /foo => /,foo 68/// foo/ => foo,. 69/// /foo/bar => /,foo,bar 70/// ../ => ..,. 71/// C:\foo\bar => C:,\,foo,bar 72/// @endcode 73class const_iterator 74 : public iterator_facade_base<const_iterator, std::input_iterator_tag, 75 const StringRef> { 76 StringRef Path; ///< The entire path. 77 StringRef Component; ///< The current component. Not necessarily in Path. 78 size_t Position = 0; ///< The iterators current position within Path. 79 Style S = Style::native; ///< The path style to use. 80 81 // An end iterator has Position = Path.size() + 1. 82 friend const_iterator begin(StringRef path, Style style); 83 friend const_iterator end(StringRef path); 84 85public: 86 reference operator*() const { return Component; } 87 const_iterator &operator++(); // preincrement 88 bool operator==(const const_iterator &RHS) const; 89 90 /// Difference in bytes between this and RHS. 91 ptrdiff_t operator-(const const_iterator &RHS) const; 92}; 93 94/// Reverse path iterator. 95/// 96/// This is an input iterator that iterates over the individual components in 97/// \a path in reverse order. The traversal order is exactly reversed from that 98/// of \a const_iterator 99class reverse_iterator 100 : public iterator_facade_base<reverse_iterator, std::input_iterator_tag, 101 const StringRef> { 102 StringRef Path; ///< The entire path. 103 StringRef Component; ///< The current component. Not necessarily in Path. 104 size_t Position = 0; ///< The iterators current position within Path. 105 Style S = Style::native; ///< The path style to use. 106 107 friend reverse_iterator rbegin(StringRef path, Style style); 108 friend reverse_iterator rend(StringRef path); 109 110public: 111 reference operator*() const { return Component; } 112 reverse_iterator &operator++(); // preincrement 113 bool operator==(const reverse_iterator &RHS) const; 114 115 /// Difference in bytes between this and RHS. 116 ptrdiff_t operator-(const reverse_iterator &RHS) const; 117}; 118 119/// Get begin iterator over \a path. 120/// @param path Input path. 121/// @returns Iterator initialized with the first component of \a path. 122const_iterator begin(StringRef path, Style style = Style::native); 123 124/// Get end iterator over \a path. 125/// @param path Input path. 126/// @returns Iterator initialized to the end of \a path. 127const_iterator end(StringRef path); 128 129/// Get reverse begin iterator over \a path. 130/// @param path Input path. 131/// @returns Iterator initialized with the first reverse component of \a path. 132reverse_iterator rbegin(StringRef path, Style style = Style::native); 133 134/// Get reverse end iterator over \a path. 135/// @param path Input path. 136/// @returns Iterator initialized to the reverse end of \a path. 137reverse_iterator rend(StringRef path); 138 139/// @} 140/// @name Lexical Modifiers 141/// @{ 142 143/// Remove the last component from \a path unless it is the root dir. 144/// 145/// Similar to the POSIX "dirname" utility. 146/// 147/// @code 148/// directory/filename.cpp => directory/ 149/// directory/ => directory 150/// filename.cpp => <empty> 151/// / => / 152/// @endcode 153/// 154/// @param path A path that is modified to not have a file component. 155void remove_filename(SmallVectorImpl<char> &path, Style style = Style::native); 156 157/// Replace the file extension of \a path with \a extension. 158/// 159/// @code 160/// ./filename.cpp => ./filename.extension 161/// ./filename => ./filename.extension 162/// ./ => ./.extension 163/// @endcode 164/// 165/// @param path A path that has its extension replaced with \a extension. 166/// @param extension The extension to be added. It may be empty. It may also 167/// optionally start with a '.', if it does not, one will be 168/// prepended. 169void replace_extension(SmallVectorImpl<char> &path, const Twine &extension, 170 Style style = Style::native); 171 172/// Replace matching path prefix with another path. 173/// 174/// @code 175/// /foo, /old, /new => /foo 176/// /old, /old, /new => /new 177/// /old, /old/, /new => /old 178/// /old/foo, /old, /new => /new/foo 179/// /old/foo, /old/, /new => /new/foo 180/// /old/foo, /old/, /new/ => /new/foo 181/// /oldfoo, /old, /new => /oldfoo 182/// /foo, <empty>, /new => /new/foo 183/// /foo, <empty>, new => new/foo 184/// /old/foo, /old, <empty> => /foo 185/// @endcode 186/// 187/// @param Path If \a Path starts with \a OldPrefix modify to instead 188/// start with \a NewPrefix. 189/// @param OldPrefix The path prefix to strip from \a Path. 190/// @param NewPrefix The path prefix to replace \a NewPrefix with. 191/// @param style The style used to match the prefix. Exact match using 192/// Posix style, case/separator insensitive match for Windows style. 193/// @result true if \a Path begins with OldPrefix 194bool replace_path_prefix(SmallVectorImpl<char> &Path, StringRef OldPrefix, 195 StringRef NewPrefix, 196 Style style = Style::native); 197 198/// Remove redundant leading "./" pieces and consecutive separators. 199/// 200/// @param path Input path. 201/// @result The cleaned-up \a path. 202StringRef remove_leading_dotslash(StringRef path, Style style = Style::native); 203 204/// In-place remove any './' and optionally '../' components from a path. 205/// 206/// @param path processed path 207/// @param remove_dot_dot specify if '../' (except for leading "../") should be 208/// removed 209/// @result True if path was changed 210bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot = false, 211 Style style = Style::native); 212 213/// Append to path. 214/// 215/// @code 216/// /foo + bar/f => /foo/bar/f 217/// /foo/ + bar/f => /foo/bar/f 218/// foo + bar/f => foo/bar/f 219/// @endcode 220/// 221/// @param path Set to \a path + \a component. 222/// @param a The component to be appended to \a path. 223void append(SmallVectorImpl<char> &path, const Twine &a, 224 const Twine &b = "", 225 const Twine &c = "", 226 const Twine &d = ""); 227 228void append(SmallVectorImpl<char> &path, Style style, const Twine &a, 229 const Twine &b = "", const Twine &c = "", const Twine &d = ""); 230 231/// Append to path. 232/// 233/// @code 234/// /foo + [bar,f] => /foo/bar/f 235/// /foo/ + [bar,f] => /foo/bar/f 236/// foo + [bar,f] => foo/bar/f 237/// @endcode 238/// 239/// @param path Set to \a path + [\a begin, \a end). 240/// @param begin Start of components to append. 241/// @param end One past the end of components to append. 242void append(SmallVectorImpl<char> &path, const_iterator begin, 243 const_iterator end, Style style = Style::native); 244 245/// @} 246/// @name Transforms (or some other better name) 247/// @{ 248 249/// Convert path to the native form. This is used to give paths to users and 250/// operating system calls in the platform's normal way. For example, on Windows 251/// all '/' are converted to '\'. On Unix, it converts all '\' to '/'. 252/// 253/// @param path A path that is transformed to native format. 254/// @param result Holds the result of the transformation. 255void native(const Twine &path, SmallVectorImpl<char> &result, 256 Style style = Style::native); 257 258/// Convert path to the native form in place. This is used to give paths to 259/// users and operating system calls in the platform's normal way. For example, 260/// on Windows all '/' are converted to '\'. 261/// 262/// @param path A path that is transformed to native format. 263void native(SmallVectorImpl<char> &path, Style style = Style::native); 264 265/// For Windows path styles, convert path to use the preferred path separators. 266/// For other styles, do nothing. 267/// 268/// @param path A path that is transformed to preferred format. 269inline void make_preferred(SmallVectorImpl<char> &path, 270 Style style = Style::native) { 271 if (!is_style_windows(style)) 272 return; 273 native(path, style); 274} 275 276/// Replaces backslashes with slashes if Windows. 277/// 278/// @param path processed path 279/// @result The result of replacing backslashes with forward slashes if Windows. 280/// On Unix, this function is a no-op because backslashes are valid path 281/// chracters. 282std::string convert_to_slash(StringRef path, Style style = Style::native); 283 284/// @} 285/// @name Lexical Observers 286/// @{ 287 288/// Get root name. 289/// 290/// @code 291/// //net/hello => //net 292/// c:/hello => c: (on Windows, on other platforms nothing) 293/// /hello => <empty> 294/// @endcode 295/// 296/// @param path Input path. 297/// @result The root name of \a path if it has one, otherwise "". 298StringRef root_name(StringRef path, Style style = Style::native); 299 300/// Get root directory. 301/// 302/// @code 303/// /goo/hello => / 304/// c:/hello => / 305/// d/file.txt => <empty> 306/// @endcode 307/// 308/// @param path Input path. 309/// @result The root directory of \a path if it has one, otherwise 310/// "". 311StringRef root_directory(StringRef path, Style style = Style::native); 312 313/// Get root path. 314/// 315/// Equivalent to root_name + root_directory. 316/// 317/// @param path Input path. 318/// @result The root path of \a path if it has one, otherwise "". 319StringRef root_path(StringRef path, Style style = Style::native); 320 321/// Get relative path. 322/// 323/// @code 324/// C:\hello\world => hello\world 325/// foo/bar => foo/bar 326/// /foo/bar => foo/bar 327/// @endcode 328/// 329/// @param path Input path. 330/// @result The path starting after root_path if one exists, otherwise "". 331StringRef relative_path(StringRef path, Style style = Style::native); 332 333/// Get parent path. 334/// 335/// @code 336/// / => <empty> 337/// /foo => / 338/// foo/../bar => foo/.. 339/// @endcode 340/// 341/// @param path Input path. 342/// @result The parent path of \a path if one exists, otherwise "". 343StringRef parent_path(StringRef path, Style style = Style::native); 344 345/// Get filename. 346/// 347/// @code 348/// /foo.txt => foo.txt 349/// . => . 350/// .. => .. 351/// / => / 352/// @endcode 353/// 354/// @param path Input path. 355/// @result The filename part of \a path. This is defined as the last component 356/// of \a path. Similar to the POSIX "basename" utility. 357StringRef filename(StringRef path, Style style = Style::native); 358 359/// Get stem. 360/// 361/// If filename contains a dot but not solely one or two dots, result is the 362/// substring of filename ending at (but not including) the last dot. Otherwise 363/// it is filename. 364/// 365/// @code 366/// /foo/bar.txt => bar 367/// /foo/bar => bar 368/// /foo/.txt => <empty> 369/// /foo/. => . 370/// /foo/.. => .. 371/// @endcode 372/// 373/// @param path Input path. 374/// @result The stem of \a path. 375StringRef stem(StringRef path, Style style = Style::native); 376 377/// Get extension. 378/// 379/// If filename contains a dot but not solely one or two dots, result is the 380/// substring of filename starting at (and including) the last dot, and ending 381/// at the end of \a path. Otherwise "". 382/// 383/// @code 384/// /foo/bar.txt => .txt 385/// /foo/bar => <empty> 386/// /foo/.txt => .txt 387/// @endcode 388/// 389/// @param path Input path. 390/// @result The extension of \a path. 391StringRef extension(StringRef path, Style style = Style::native); 392 393/// Check whether the given char is a path separator on the host OS. 394/// 395/// @param value a character 396/// @result true if \a value is a path separator character on the host OS 397bool is_separator(char value, Style style = Style::native); 398 399/// Return the preferred separator for this platform. 400/// 401/// @result StringRef of the preferred separator, null-terminated. 402StringRef get_separator(Style style = Style::native); 403 404/// Get the typical temporary directory for the system, e.g., 405/// "/var/tmp" or "C:/TEMP" 406/// 407/// @param erasedOnReboot Whether to favor a path that is erased on reboot 408/// rather than one that potentially persists longer. This parameter will be 409/// ignored if the user or system has set the typical environment variable 410/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory. 411/// 412/// @param result Holds the resulting path name. 413void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result); 414 415/// Get the user's home directory. 416/// 417/// @param result Holds the resulting path name. 418/// @result True if a home directory is set, false otherwise. 419bool home_directory(SmallVectorImpl<char> &result); 420 421/// Get the directory where packages should read user-specific configurations. 422/// e.g. $XDG_CONFIG_HOME. 423/// 424/// @param result Holds the resulting path name. 425/// @result True if the appropriate path was determined, it need not exist. 426bool user_config_directory(SmallVectorImpl<char> &result); 427 428/// Get the directory where installed packages should put their 429/// machine-local cache, e.g. $XDG_CACHE_HOME. 430/// 431/// @param result Holds the resulting path name. 432/// @result True if the appropriate path was determined, it need not exist. 433bool cache_directory(SmallVectorImpl<char> &result); 434 435/// Has root name? 436/// 437/// root_name != "" 438/// 439/// @param path Input path. 440/// @result True if the path has a root name, false otherwise. 441bool has_root_name(const Twine &path, Style style = Style::native); 442 443/// Has root directory? 444/// 445/// root_directory != "" 446/// 447/// @param path Input path. 448/// @result True if the path has a root directory, false otherwise. 449bool has_root_directory(const Twine &path, Style style = Style::native); 450 451/// Has root path? 452/// 453/// root_path != "" 454/// 455/// @param path Input path. 456/// @result True if the path has a root path, false otherwise. 457bool has_root_path(const Twine &path, Style style = Style::native); 458 459/// Has relative path? 460/// 461/// relative_path != "" 462/// 463/// @param path Input path. 464/// @result True if the path has a relative path, false otherwise. 465bool has_relative_path(const Twine &path, Style style = Style::native); 466 467/// Has parent path? 468/// 469/// parent_path != "" 470/// 471/// @param path Input path. 472/// @result True if the path has a parent path, false otherwise. 473bool has_parent_path(const Twine &path, Style style = Style::native); 474 475/// Has filename? 476/// 477/// filename != "" 478/// 479/// @param path Input path. 480/// @result True if the path has a filename, false otherwise. 481bool has_filename(const Twine &path, Style style = Style::native); 482 483/// Has stem? 484/// 485/// stem != "" 486/// 487/// @param path Input path. 488/// @result True if the path has a stem, false otherwise. 489bool has_stem(const Twine &path, Style style = Style::native); 490 491/// Has extension? 492/// 493/// extension != "" 494/// 495/// @param path Input path. 496/// @result True if the path has a extension, false otherwise. 497bool has_extension(const Twine &path, Style style = Style::native); 498 499/// Is path absolute? 500/// 501/// According to cppreference.com, C++17 states: "An absolute path is a path 502/// that unambiguously identifies the location of a file without reference to 503/// an additional starting location." 504/// 505/// In other words, the rules are: 506/// 1) POSIX style paths with nonempty root directory are absolute. 507/// 2) Windows style paths with nonempty root name and root directory are 508/// absolute. 509/// 3) No other paths are absolute. 510/// 511/// \see has_root_name 512/// \see has_root_directory 513/// 514/// @param path Input path. 515/// @result True if the path is absolute, false if it is not. 516bool is_absolute(const Twine &path, Style style = Style::native); 517 518/// Is path absolute using GNU rules? 519/// 520/// GNU rules are: 521/// 1) Paths starting with a path separator are absolute. 522/// 2) Windows style paths are also absolute if they start with a character 523/// followed by ':'. 524/// 3) No other paths are absolute. 525/// 526/// On Windows style the path "C:\Users\Default" has "C:" as root name and "\" 527/// as root directory. 528/// 529/// Hence "C:" on Windows is absolute under GNU rules and not absolute under 530/// C++17 because it has no root directory. Likewise "/" and "\" on Windows are 531/// absolute under GNU and are not absolute under C++17 due to empty root name. 532/// 533/// \see has_root_name 534/// \see has_root_directory 535/// 536/// @param path Input path. 537/// @param style The style of \p path (e.g. Windows or POSIX). "native" style 538/// means to derive the style from the host. 539/// @result True if the path is absolute following GNU rules, false if it is 540/// not. 541bool is_absolute_gnu(const Twine &path, Style style = Style::native); 542 543/// Is path relative? 544/// 545/// @param path Input path. 546/// @result True if the path is relative, false if it is not. 547bool is_relative(const Twine &path, Style style = Style::native); 548 549} // end namespace path 550} // end namespace sys 551} // end namespace llvm 552 553#endif 554