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      1 //===- llvm/Support/PathV2.h - Path Operating System Concept ----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file declares the llvm::sys::path namespace. It is designed after
     11 // TR2/boost filesystem (v3), but modified to remove exception handling and the
     12 // path class.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #ifndef LLVM_SUPPORT_PATHV2_H
     17 #define LLVM_SUPPORT_PATHV2_H
     18 
     19 #include "llvm/ADT/SmallString.h"
     20 #include "llvm/ADT/Twine.h"
     21 #include "llvm/Support/DataTypes.h"
     22 #include <iterator>
     23 
     24 namespace llvm {
     25 namespace sys {
     26 namespace path {
     27 
     28 /// @name Lexical Component Iterator
     29 /// @{
     30 
     31 /// @brief Path iterator.
     32 ///
     33 /// This is a bidirectional iterator that iterates over the individual
     34 /// components in \a path. The forward traversal order is as follows:
     35 /// * The root-name element, if present.
     36 /// * The root-directory element, if present.
     37 /// * Each successive filename element, if present.
     38 /// * Dot, if one or more trailing non-root slash characters are present.
     39 /// The backwards traversal order is the reverse of forward traversal.
     40 ///
     41 /// Iteration examples. Each component is separated by ',':
     42 /// /          => /
     43 /// /foo       => /,foo
     44 /// foo/       => foo,.
     45 /// /foo/bar   => /,foo,bar
     46 /// ../        => ..,.
     47 /// C:\foo\bar => C:,/,foo,bar
     48 ///
     49 class const_iterator {
     50   StringRef Path;      //< The entire path.
     51   StringRef Component; //< The current component. Not necessarily in Path.
     52   size_t    Position;  //< The iterators current position within Path.
     53 
     54   // An end iterator has Position = Path.size() + 1.
     55   friend const_iterator begin(StringRef path);
     56   friend const_iterator end(StringRef path);
     57 
     58 public:
     59   typedef const StringRef value_type;
     60   typedef ptrdiff_t difference_type;
     61   typedef value_type &reference;
     62   typedef value_type *pointer;
     63   typedef std::bidirectional_iterator_tag iterator_category;
     64 
     65   reference operator*() const { return Component; }
     66   pointer   operator->() const { return &Component; }
     67   const_iterator &operator++();    // preincrement
     68   const_iterator &operator++(int); // postincrement
     69   const_iterator &operator--();    // predecrement
     70   const_iterator &operator--(int); // postdecrement
     71   bool operator==(const const_iterator &RHS) const;
     72   bool operator!=(const const_iterator &RHS) const;
     73 
     74   /// @brief Difference in bytes between this and RHS.
     75   ptrdiff_t operator-(const const_iterator &RHS) const;
     76 };
     77 
     78 typedef std::reverse_iterator<const_iterator> reverse_iterator;
     79 
     80 /// @brief Get begin iterator over \a path.
     81 /// @param path Input path.
     82 /// @returns Iterator initialized with the first component of \a path.
     83 const_iterator begin(StringRef path);
     84 
     85 /// @brief Get end iterator over \a path.
     86 /// @param path Input path.
     87 /// @returns Iterator initialized to the end of \a path.
     88 const_iterator end(StringRef path);
     89 
     90 /// @brief Get reverse begin iterator over \a path.
     91 /// @param path Input path.
     92 /// @returns Iterator initialized with the first reverse component of \a path.
     93 inline reverse_iterator rbegin(StringRef path) {
     94   return reverse_iterator(end(path));
     95 }
     96 
     97 /// @brief Get reverse end iterator over \a path.
     98 /// @param path Input path.
     99 /// @returns Iterator initialized to the reverse end of \a path.
    100 inline reverse_iterator rend(StringRef path) {
    101   return reverse_iterator(begin(path));
    102 }
    103 
    104 /// @}
    105 /// @name Lexical Modifiers
    106 /// @{
    107 
    108 /// @brief Remove the last component from \a path unless it is the root dir.
    109 ///
    110 /// directory/filename.cpp => directory/
    111 /// directory/             => directory
    112 /// /                      => /
    113 ///
    114 /// @param path A path that is modified to not have a file component.
    115 void remove_filename(SmallVectorImpl<char> &path);
    116 
    117 /// @brief Replace the file extension of \a path with \a extension.
    118 ///
    119 /// ./filename.cpp => ./filename.extension
    120 /// ./filename     => ./filename.extension
    121 /// ./             => ./.extension
    122 ///
    123 /// @param path A path that has its extension replaced with \a extension.
    124 /// @param extension The extension to be added. It may be empty. It may also
    125 ///                  optionally start with a '.', if it does not, one will be
    126 ///                  prepended.
    127 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension);
    128 
    129 /// @brief Append to path.
    130 ///
    131 /// /foo  + bar/f => /foo/bar/f
    132 /// /foo/ + bar/f => /foo/bar/f
    133 /// foo   + bar/f => foo/bar/f
    134 ///
    135 /// @param path Set to \a path + \a component.
    136 /// @param component The component to be appended to \a path.
    137 void append(SmallVectorImpl<char> &path, const Twine &a,
    138                                          const Twine &b = "",
    139                                          const Twine &c = "",
    140                                          const Twine &d = "");
    141 
    142 /// @brief Append to path.
    143 ///
    144 /// /foo  + [bar,f] => /foo/bar/f
    145 /// /foo/ + [bar,f] => /foo/bar/f
    146 /// foo   + [bar,f] => foo/bar/f
    147 ///
    148 /// @param path Set to \a path + [\a begin, \a end).
    149 /// @param begin Start of components to append.
    150 /// @param end One past the end of components to append.
    151 void append(SmallVectorImpl<char> &path,
    152             const_iterator begin, const_iterator end);
    153 
    154 /// @}
    155 /// @name Transforms (or some other better name)
    156 /// @{
    157 
    158 /// Convert path to the native form. This is used to give paths to users and
    159 /// operating system calls in the platform's normal way. For example, on Windows
    160 /// all '/' are converted to '\'.
    161 ///
    162 /// @param path A path that is transformed to native format.
    163 /// @param result Holds the result of the transformation.
    164 void native(const Twine &path, SmallVectorImpl<char> &result);
    165 
    166 /// @}
    167 /// @name Lexical Observers
    168 /// @{
    169 
    170 /// @brief Get root name.
    171 ///
    172 /// //net/hello => //net
    173 /// c:/hello    => c: (on Windows, on other platforms nothing)
    174 /// /hello      => <empty>
    175 ///
    176 /// @param path Input path.
    177 /// @result The root name of \a path if it has one, otherwise "".
    178 const StringRef root_name(StringRef path);
    179 
    180 /// @brief Get root directory.
    181 ///
    182 /// /goo/hello => /
    183 /// c:/hello   => /
    184 /// d/file.txt => <empty>
    185 ///
    186 /// @param path Input path.
    187 /// @result The root directory of \a path if it has one, otherwise
    188 ///               "".
    189 const StringRef root_directory(StringRef path);
    190 
    191 /// @brief Get root path.
    192 ///
    193 /// Equivalent to root_name + root_directory.
    194 ///
    195 /// @param path Input path.
    196 /// @result The root path of \a path if it has one, otherwise "".
    197 const StringRef root_path(StringRef path);
    198 
    199 /// @brief Get relative path.
    200 ///
    201 /// C:\hello\world => hello\world
    202 /// foo/bar        => foo/bar
    203 /// /foo/bar       => foo/bar
    204 ///
    205 /// @param path Input path.
    206 /// @result The path starting after root_path if one exists, otherwise "".
    207 const StringRef relative_path(StringRef path);
    208 
    209 /// @brief Get parent path.
    210 ///
    211 /// /          => <empty>
    212 /// /foo       => /
    213 /// foo/../bar => foo/..
    214 ///
    215 /// @param path Input path.
    216 /// @result The parent path of \a path if one exists, otherwise "".
    217 const StringRef parent_path(StringRef path);
    218 
    219 /// @brief Get filename.
    220 ///
    221 /// /foo.txt    => foo.txt
    222 /// .          => .
    223 /// ..         => ..
    224 /// /          => /
    225 ///
    226 /// @param path Input path.
    227 /// @result The filename part of \a path. This is defined as the last component
    228 ///         of \a path.
    229 const StringRef filename(StringRef path);
    230 
    231 /// @brief Get stem.
    232 ///
    233 /// If filename contains a dot but not solely one or two dots, result is the
    234 /// substring of filename ending at (but not including) the last dot. Otherwise
    235 /// it is filename.
    236 ///
    237 /// /foo/bar.txt => bar
    238 /// /foo/bar     => bar
    239 /// /foo/.txt    => <empty>
    240 /// /foo/.       => .
    241 /// /foo/..      => ..
    242 ///
    243 /// @param path Input path.
    244 /// @result The stem of \a path.
    245 const StringRef stem(StringRef path);
    246 
    247 /// @brief Get extension.
    248 ///
    249 /// If filename contains a dot but not solely one or two dots, result is the
    250 /// substring of filename starting at (and including) the last dot, and ending
    251 /// at the end of \a path. Otherwise "".
    252 ///
    253 /// /foo/bar.txt => .txt
    254 /// /foo/bar     => <empty>
    255 /// /foo/.txt    => .txt
    256 ///
    257 /// @param path Input path.
    258 /// @result The extension of \a path.
    259 const StringRef extension(StringRef path);
    260 
    261 /// @brief Check whether the given char is a path separator on the host OS.
    262 ///
    263 /// @param value a character
    264 /// @result true if \a value is a path separator character on the host OS
    265 bool is_separator(char value);
    266 
    267 /// @brief Get the typical temporary directory for the system, e.g.,
    268 /// "/var/tmp" or "C:/TEMP"
    269 ///
    270 /// @param erasedOnReboot Whether to favor a path that is erased on reboot
    271 /// rather than one that potentially persists longer. This parameter will be
    272 /// ignored if the user or system has set the typical environment variable
    273 /// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
    274 ///
    275 /// @param Result Holds the resulting path name.
    276 void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
    277 
    278 /// @brief Has root name?
    279 ///
    280 /// root_name != ""
    281 ///
    282 /// @param path Input path.
    283 /// @result True if the path has a root name, false otherwise.
    284 bool has_root_name(const Twine &path);
    285 
    286 /// @brief Has root directory?
    287 ///
    288 /// root_directory != ""
    289 ///
    290 /// @param path Input path.
    291 /// @result True if the path has a root directory, false otherwise.
    292 bool has_root_directory(const Twine &path);
    293 
    294 /// @brief Has root path?
    295 ///
    296 /// root_path != ""
    297 ///
    298 /// @param path Input path.
    299 /// @result True if the path has a root path, false otherwise.
    300 bool has_root_path(const Twine &path);
    301 
    302 /// @brief Has relative path?
    303 ///
    304 /// relative_path != ""
    305 ///
    306 /// @param path Input path.
    307 /// @result True if the path has a relative path, false otherwise.
    308 bool has_relative_path(const Twine &path);
    309 
    310 /// @brief Has parent path?
    311 ///
    312 /// parent_path != ""
    313 ///
    314 /// @param path Input path.
    315 /// @result True if the path has a parent path, false otherwise.
    316 bool has_parent_path(const Twine &path);
    317 
    318 /// @brief Has filename?
    319 ///
    320 /// filename != ""
    321 ///
    322 /// @param path Input path.
    323 /// @result True if the path has a filename, false otherwise.
    324 bool has_filename(const Twine &path);
    325 
    326 /// @brief Has stem?
    327 ///
    328 /// stem != ""
    329 ///
    330 /// @param path Input path.
    331 /// @result True if the path has a stem, false otherwise.
    332 bool has_stem(const Twine &path);
    333 
    334 /// @brief Has extension?
    335 ///
    336 /// extension != ""
    337 ///
    338 /// @param path Input path.
    339 /// @result True if the path has a extension, false otherwise.
    340 bool has_extension(const Twine &path);
    341 
    342 /// @brief Is path absolute?
    343 ///
    344 /// @param path Input path.
    345 /// @result True if the path is absolute, false if it is not.
    346 bool is_absolute(const Twine &path);
    347 
    348 /// @brief Is path relative?
    349 ///
    350 /// @param path Input path.
    351 /// @result True if the path is relative, false if it is not.
    352 bool is_relative(const Twine &path);
    353 
    354 } // end namespace path
    355 } // end namespace sys
    356 } // end namespace llvm
    357 
    358 #endif
    359