1 //===- llvm/Support/Path.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_PATH_H
17 #define LLVM_SUPPORT_PATH_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 an input iterator that iterates over the individual components in
34 /// \a path. The 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 /// Traversing backwards is possible with \a reverse_iterator
40 ///
41 /// Iteration examples. Each component is separated by ',':
42 /// @code
43 ///   /          => /
44 ///   /foo       => /,foo
45 ///   foo/       => foo,.
46 ///   /foo/bar   => /,foo,bar
47 ///   ../        => ..,.
48 ///   C:\foo\bar => C:,/,foo,bar
49 /// @endcode
50 class const_iterator
51     : public std::iterator<std::input_iterator_tag, const StringRef> {
52   StringRef Path;      ///< The entire path.
53   StringRef Component; ///< The current component. Not necessarily in Path.
54   size_t    Position;  ///< The iterators current position within Path.
55 
56   // An end iterator has Position = Path.size() + 1.
57   friend const_iterator begin(StringRef path);
58   friend const_iterator end(StringRef path);
59 
60 public:
61   reference operator*() const { return Component; }
62   pointer   operator->() const { return &Component; }
63   const_iterator &operator++();    // preincrement
64   const_iterator &operator++(int); // postincrement
65   bool operator==(const const_iterator &RHS) const;
66   bool operator!=(const const_iterator &RHS) const { return !(*this == RHS); }
67 
68   /// @brief Difference in bytes between this and RHS.
69   ptrdiff_t operator-(const const_iterator &RHS) const;
70 };
71 
72 /// @brief Reverse path iterator.
73 ///
74 /// This is an input iterator that iterates over the individual components in
75 /// \a path in reverse order. The traversal order is exactly reversed from that
76 /// of \a const_iterator
77 class reverse_iterator
78     : public std::iterator<std::input_iterator_tag, const StringRef> {
79   StringRef Path;      ///< The entire path.
80   StringRef Component; ///< The current component. Not necessarily in Path.
81   size_t    Position;  ///< The iterators current position within Path.
82 
83   friend reverse_iterator rbegin(StringRef path);
84   friend reverse_iterator rend(StringRef path);
85 
86 public:
87   reference operator*() const { return Component; }
88   pointer   operator->() const { return &Component; }
89   reverse_iterator &operator++();    // preincrement
90   reverse_iterator &operator++(int); // postincrement
91   bool operator==(const reverse_iterator &RHS) const;
92   bool operator!=(const reverse_iterator &RHS) const { return !(*this == RHS); }
93 };
94 
95 /// @brief Get begin iterator over \a path.
96 /// @param path Input path.
97 /// @returns Iterator initialized with the first component of \a path.
98 const_iterator begin(StringRef path);
99 
100 /// @brief Get end iterator over \a path.
101 /// @param path Input path.
102 /// @returns Iterator initialized to the end of \a path.
103 const_iterator end(StringRef path);
104 
105 /// @brief Get reverse begin iterator over \a path.
106 /// @param path Input path.
107 /// @returns Iterator initialized with the first reverse component of \a path.
108 reverse_iterator rbegin(StringRef path);
109 
110 /// @brief Get reverse end iterator over \a path.
111 /// @param path Input path.
112 /// @returns Iterator initialized to the reverse end of \a path.
113 reverse_iterator rend(StringRef path);
114 
115 /// @}
116 /// @name Lexical Modifiers
117 /// @{
118 
119 /// @brief Remove the last component from \a path unless it is the root dir.
120 ///
121 /// @code
122 ///   directory/filename.cpp => directory/
123 ///   directory/             => directory
124 ///   filename.cpp           => <empty>
125 ///   /                      => /
126 /// @endcode
127 ///
128 /// @param path A path that is modified to not have a file component.
129 void remove_filename(SmallVectorImpl<char> &path);
130 
131 /// @brief Replace the file extension of \a path with \a extension.
132 ///
133 /// @code
134 ///   ./filename.cpp => ./filename.extension
135 ///   ./filename     => ./filename.extension
136 ///   ./             => ./.extension
137 /// @endcode
138 ///
139 /// @param path A path that has its extension replaced with \a extension.
140 /// @param extension The extension to be added. It may be empty. It may also
141 ///                  optionally start with a '.', if it does not, one will be
142 ///                  prepended.
143 void replace_extension(SmallVectorImpl<char> &path, const Twine &extension);
144 
145 /// @brief Append to path.
146 ///
147 /// @code
148 ///   /foo  + bar/f => /foo/bar/f
149 ///   /foo/ + bar/f => /foo/bar/f
150 ///   foo   + bar/f => foo/bar/f
151 /// @endcode
152 ///
153 /// @param path Set to \a path + \a component.
154 /// @param a The component to be appended to \a path.
155 void append(SmallVectorImpl<char> &path, const Twine &a,
156                                          const Twine &b = "",
157                                          const Twine &c = "",
158                                          const Twine &d = "");
159 
160 /// @brief Append to path.
161 ///
162 /// @code
163 ///   /foo  + [bar,f] => /foo/bar/f
164 ///   /foo/ + [bar,f] => /foo/bar/f
165 ///   foo   + [bar,f] => foo/bar/f
166 /// @endcode
167 ///
168 /// @param path Set to \a path + [\a begin, \a end).
169 /// @param begin Start of components to append.
170 /// @param end One past the end of components to append.
171 void append(SmallVectorImpl<char> &path,
172             const_iterator begin, const_iterator end);
173 
174 /// @}
175 /// @name Transforms (or some other better name)
176 /// @{
177 
178 /// Convert path to the native form. This is used to give paths to users and
179 /// operating system calls in the platform's normal way. For example, on Windows
180 /// all '/' are converted to '\'.
181 ///
182 /// @param path A path that is transformed to native format.
183 /// @param result Holds the result of the transformation.
184 void native(const Twine &path, SmallVectorImpl<char> &result);
185 
186 /// Convert path to the native form in place. This is used to give paths to
187 /// users and operating system calls in the platform's normal way. For example,
188 /// on Windows all '/' are converted to '\'.
189 ///
190 /// @param path A path that is transformed to native format.
191 void native(SmallVectorImpl<char> &path);
192 
193 /// @}
194 /// @name Lexical Observers
195 /// @{
196 
197 /// @brief Get root name.
198 ///
199 /// @code
200 ///   //net/hello => //net
201 ///   c:/hello    => c: (on Windows, on other platforms nothing)
202 ///   /hello      => <empty>
203 /// @endcode
204 ///
205 /// @param path Input path.
206 /// @result The root name of \a path if it has one, otherwise "".
207 StringRef root_name(StringRef path);
208 
209 /// @brief Get root directory.
210 ///
211 /// @code
212 ///   /goo/hello => /
213 ///   c:/hello   => /
214 ///   d/file.txt => <empty>
215 /// @endcode
216 ///
217 /// @param path Input path.
218 /// @result The root directory of \a path if it has one, otherwise
219 ///               "".
220 StringRef root_directory(StringRef path);
221 
222 /// @brief Get root path.
223 ///
224 /// Equivalent to root_name + root_directory.
225 ///
226 /// @param path Input path.
227 /// @result The root path of \a path if it has one, otherwise "".
228 StringRef root_path(StringRef path);
229 
230 /// @brief Get relative path.
231 ///
232 /// @code
233 ///   C:\hello\world => hello\world
234 ///   foo/bar        => foo/bar
235 ///   /foo/bar       => foo/bar
236 /// @endcode
237 ///
238 /// @param path Input path.
239 /// @result The path starting after root_path if one exists, otherwise "".
240 StringRef relative_path(StringRef path);
241 
242 /// @brief Get parent path.
243 ///
244 /// @code
245 ///   /          => <empty>
246 ///   /foo       => /
247 ///   foo/../bar => foo/..
248 /// @endcode
249 ///
250 /// @param path Input path.
251 /// @result The parent path of \a path if one exists, otherwise "".
252 StringRef parent_path(StringRef path);
253 
254 /// @brief Get filename.
255 ///
256 /// @code
257 ///   /foo.txt    => foo.txt
258 ///   .          => .
259 ///   ..         => ..
260 ///   /          => /
261 /// @endcode
262 ///
263 /// @param path Input path.
264 /// @result The filename part of \a path. This is defined as the last component
265 ///         of \a path.
266 StringRef filename(StringRef path);
267 
268 /// @brief Get stem.
269 ///
270 /// If filename contains a dot but not solely one or two dots, result is the
271 /// substring of filename ending at (but not including) the last dot. Otherwise
272 /// it is filename.
273 ///
274 /// @code
275 ///   /foo/bar.txt => bar
276 ///   /foo/bar     => bar
277 ///   /foo/.txt    => <empty>
278 ///   /foo/.       => .
279 ///   /foo/..      => ..
280 /// @endcode
281 ///
282 /// @param path Input path.
283 /// @result The stem of \a path.
284 StringRef stem(StringRef path);
285 
286 /// @brief Get extension.
287 ///
288 /// If filename contains a dot but not solely one or two dots, result is the
289 /// substring of filename starting at (and including) the last dot, and ending
290 /// at the end of \a path. Otherwise "".
291 ///
292 /// @code
293 ///   /foo/bar.txt => .txt
294 ///   /foo/bar     => <empty>
295 ///   /foo/.txt    => .txt
296 /// @endcode
297 ///
298 /// @param path Input path.
299 /// @result The extension of \a path.
300 StringRef extension(StringRef path);
301 
302 /// @brief Check whether the given char is a path separator on the host OS.
303 ///
304 /// @param value a character
305 /// @result true if \a value is a path separator character on the host OS
306 bool is_separator(char value);
307 
308 /// @brief Return the preferred separator for this platform.
309 ///
310 /// @result StringRef of the preferred separator, null-terminated.
311 StringRef get_separator();
312 
313 /// @brief Get the typical temporary directory for the system, e.g.,
314 /// "/var/tmp" or "C:/TEMP"
315 ///
316 /// @param erasedOnReboot Whether to favor a path that is erased on reboot
317 /// rather than one that potentially persists longer. This parameter will be
318 /// ignored if the user or system has set the typical environment variable
319 /// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
320 ///
321 /// @param result Holds the resulting path name.
322 void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
323 
324 /// @brief Get the user's home directory.
325 ///
326 /// @param result Holds the resulting path name.
327 /// @result True if a home directory is set, false otherwise.
328 bool home_directory(SmallVectorImpl<char> &result);
329 
330 /// @brief Has root name?
331 ///
332 /// root_name != ""
333 ///
334 /// @param path Input path.
335 /// @result True if the path has a root name, false otherwise.
336 bool has_root_name(const Twine &path);
337 
338 /// @brief Has root directory?
339 ///
340 /// root_directory != ""
341 ///
342 /// @param path Input path.
343 /// @result True if the path has a root directory, false otherwise.
344 bool has_root_directory(const Twine &path);
345 
346 /// @brief Has root path?
347 ///
348 /// root_path != ""
349 ///
350 /// @param path Input path.
351 /// @result True if the path has a root path, false otherwise.
352 bool has_root_path(const Twine &path);
353 
354 /// @brief Has relative path?
355 ///
356 /// relative_path != ""
357 ///
358 /// @param path Input path.
359 /// @result True if the path has a relative path, false otherwise.
360 bool has_relative_path(const Twine &path);
361 
362 /// @brief Has parent path?
363 ///
364 /// parent_path != ""
365 ///
366 /// @param path Input path.
367 /// @result True if the path has a parent path, false otherwise.
368 bool has_parent_path(const Twine &path);
369 
370 /// @brief Has filename?
371 ///
372 /// filename != ""
373 ///
374 /// @param path Input path.
375 /// @result True if the path has a filename, false otherwise.
376 bool has_filename(const Twine &path);
377 
378 /// @brief Has stem?
379 ///
380 /// stem != ""
381 ///
382 /// @param path Input path.
383 /// @result True if the path has a stem, false otherwise.
384 bool has_stem(const Twine &path);
385 
386 /// @brief Has extension?
387 ///
388 /// extension != ""
389 ///
390 /// @param path Input path.
391 /// @result True if the path has a extension, false otherwise.
392 bool has_extension(const Twine &path);
393 
394 /// @brief Is path absolute?
395 ///
396 /// @param path Input path.
397 /// @result True if the path is absolute, false if it is not.
398 bool is_absolute(const Twine &path);
399 
400 /// @brief Is path relative?
401 ///
402 /// @param path Input path.
403 /// @result True if the path is relative, false if it is not.
404 bool is_relative(const Twine &path);
405 
406 } // end namespace path
407 } // end namespace sys
408 } // end namespace llvm
409 
410 #endif
411