Path.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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
24namespace llvm {
25namespace sys {
26namespace 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/// @code
43///   /          => /
44///   /foo       => /,foo
45///   foo/       => foo,.
46///   /foo/bar   => /,foo,bar
47///   ../        => ..,.
48///   C:\foo\bar => C:,/,foo,bar
49/// @endcode
50class const_iterator {
51  StringRef Path;      ///< The entire path.
52  StringRef Component; ///< The current component. Not necessarily in Path.
53  size_t    Position;  ///< The iterators current position within Path.
54
55  // An end iterator has Position = Path.size() + 1.
56  friend const_iterator begin(StringRef path);
57  friend const_iterator end(StringRef path);
58
59public:
60  typedef const StringRef value_type;
61  typedef ptrdiff_t difference_type;
62  typedef value_type &reference;
63  typedef value_type *pointer;
64  typedef std::bidirectional_iterator_tag iterator_category;
65
66  reference operator*() const { return Component; }
67  pointer   operator->() const { return &Component; }
68  const_iterator &operator++();    // preincrement
69  const_iterator &operator++(int); // postincrement
70  const_iterator &operator--();    // predecrement
71  const_iterator &operator--(int); // postdecrement
72  bool operator==(const const_iterator &RHS) const;
73  bool operator!=(const const_iterator &RHS) const;
74
75  /// @brief Difference in bytes between this and RHS.
76  ptrdiff_t operator-(const const_iterator &RHS) const;
77};
78
79typedef std::reverse_iterator<const_iterator> reverse_iterator;
80
81/// @brief Get begin iterator over \a path.
82/// @param path Input path.
83/// @returns Iterator initialized with the first component of \a path.
84const_iterator begin(StringRef path);
85
86/// @brief Get end iterator over \a path.
87/// @param path Input path.
88/// @returns Iterator initialized to the end of \a path.
89const_iterator end(StringRef path);
90
91/// @brief Get reverse begin iterator over \a path.
92/// @param path Input path.
93/// @returns Iterator initialized with the first reverse component of \a path.
94inline reverse_iterator rbegin(StringRef path) {
95  return reverse_iterator(end(path));
96}
97
98/// @brief Get reverse end iterator over \a path.
99/// @param path Input path.
100/// @returns Iterator initialized to the reverse end of \a path.
101inline reverse_iterator rend(StringRef path) {
102  return reverse_iterator(begin(path));
103}
104
105/// @}
106/// @name Lexical Modifiers
107/// @{
108
109/// @brief Remove the last component from \a path unless it is the root dir.
110///
111/// @code
112///   directory/filename.cpp => directory/
113///   directory/             => directory
114///   filename.cpp           => <empty>
115///   /                      => /
116/// @endcode
117///
118/// @param path A path that is modified to not have a file component.
119void remove_filename(SmallVectorImpl<char> &path);
120
121/// @brief Replace the file extension of \a path with \a extension.
122///
123/// @code
124///   ./filename.cpp => ./filename.extension
125///   ./filename     => ./filename.extension
126///   ./             => ./.extension
127/// @endcode
128///
129/// @param path A path that has its extension replaced with \a extension.
130/// @param extension The extension to be added. It may be empty. It may also
131///                  optionally start with a '.', if it does not, one will be
132///                  prepended.
133void replace_extension(SmallVectorImpl<char> &path, const Twine &extension);
134
135/// @brief Append to path.
136///
137/// @code
138///   /foo  + bar/f => /foo/bar/f
139///   /foo/ + bar/f => /foo/bar/f
140///   foo   + bar/f => foo/bar/f
141/// @endcode
142///
143/// @param path Set to \a path + \a component.
144/// @param a The component to be appended to \a path.
145void append(SmallVectorImpl<char> &path, const Twine &a,
146                                         const Twine &b = "",
147                                         const Twine &c = "",
148                                         const Twine &d = "");
149
150/// @brief Append to path.
151///
152/// @code
153///   /foo  + [bar,f] => /foo/bar/f
154///   /foo/ + [bar,f] => /foo/bar/f
155///   foo   + [bar,f] => foo/bar/f
156/// @endcode
157///
158/// @param path Set to \a path + [\a begin, \a end).
159/// @param begin Start of components to append.
160/// @param end One past the end of components to append.
161void append(SmallVectorImpl<char> &path,
162            const_iterator begin, const_iterator end);
163
164/// @}
165/// @name Transforms (or some other better name)
166/// @{
167
168/// Convert path to the native form. This is used to give paths to users and
169/// operating system calls in the platform's normal way. For example, on Windows
170/// all '/' are converted to '\'.
171///
172/// @param path A path that is transformed to native format.
173/// @param result Holds the result of the transformation.
174void native(const Twine &path, SmallVectorImpl<char> &result);
175
176/// Convert path to the native form in place. This is used to give paths to
177/// users and operating system calls in the platform's normal way. For example,
178/// on Windows all '/' are converted to '\'.
179///
180/// @param path A path that is transformed to native format.
181void native(SmallVectorImpl<char> &path);
182
183/// @}
184/// @name Lexical Observers
185/// @{
186
187/// @brief Get root name.
188///
189/// @code
190///   //net/hello => //net
191///   c:/hello    => c: (on Windows, on other platforms nothing)
192///   /hello      => <empty>
193/// @endcode
194///
195/// @param path Input path.
196/// @result The root name of \a path if it has one, otherwise "".
197const StringRef root_name(StringRef path);
198
199/// @brief Get root directory.
200///
201/// @code
202///   /goo/hello => /
203///   c:/hello   => /
204///   d/file.txt => <empty>
205/// @endcode
206///
207/// @param path Input path.
208/// @result The root directory of \a path if it has one, otherwise
209///               "".
210const StringRef root_directory(StringRef path);
211
212/// @brief Get root path.
213///
214/// Equivalent to root_name + root_directory.
215///
216/// @param path Input path.
217/// @result The root path of \a path if it has one, otherwise "".
218const StringRef root_path(StringRef path);
219
220/// @brief Get relative path.
221///
222/// @code
223///   C:\hello\world => hello\world
224///   foo/bar        => foo/bar
225///   /foo/bar       => foo/bar
226/// @endcode
227///
228/// @param path Input path.
229/// @result The path starting after root_path if one exists, otherwise "".
230const StringRef relative_path(StringRef path);
231
232/// @brief Get parent path.
233///
234/// @code
235///   /          => <empty>
236///   /foo       => /
237///   foo/../bar => foo/..
238/// @endcode
239///
240/// @param path Input path.
241/// @result The parent path of \a path if one exists, otherwise "".
242const StringRef parent_path(StringRef path);
243
244/// @brief Get filename.
245///
246/// @code
247///   /foo.txt    => foo.txt
248///   .          => .
249///   ..         => ..
250///   /          => /
251/// @endcode
252///
253/// @param path Input path.
254/// @result The filename part of \a path. This is defined as the last component
255///         of \a path.
256const StringRef filename(StringRef path);
257
258/// @brief Get stem.
259///
260/// If filename contains a dot but not solely one or two dots, result is the
261/// substring of filename ending at (but not including) the last dot. Otherwise
262/// it is filename.
263///
264/// @code
265///   /foo/bar.txt => bar
266///   /foo/bar     => bar
267///   /foo/.txt    => <empty>
268///   /foo/.       => .
269///   /foo/..      => ..
270/// @endcode
271///
272/// @param path Input path.
273/// @result The stem of \a path.
274const StringRef stem(StringRef path);
275
276/// @brief Get extension.
277///
278/// If filename contains a dot but not solely one or two dots, result is the
279/// substring of filename starting at (and including) the last dot, and ending
280/// at the end of \a path. Otherwise "".
281///
282/// @code
283///   /foo/bar.txt => .txt
284///   /foo/bar     => <empty>
285///   /foo/.txt    => .txt
286/// @endcode
287///
288/// @param path Input path.
289/// @result The extension of \a path.
290const StringRef extension(StringRef path);
291
292/// @brief Check whether the given char is a path separator on the host OS.
293///
294/// @param value a character
295/// @result true if \a value is a path separator character on the host OS
296bool is_separator(char value);
297
298/// @brief Return the preferred separator for this platform.
299///
300/// @result StringRef of the preferred separator, null-terminated.
301const StringRef get_separator();
302
303/// @brief Get the typical temporary directory for the system, e.g.,
304/// "/var/tmp" or "C:/TEMP"
305///
306/// @param erasedOnReboot Whether to favor a path that is erased on reboot
307/// rather than one that potentially persists longer. This parameter will be
308/// ignored if the user or system has set the typical environment variable
309/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
310///
311/// @param result Holds the resulting path name.
312void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
313
314/// @brief Get the user's home directory.
315///
316/// @param result Holds the resulting path name.
317/// @result True if a home directory is set, false otherwise.
318bool home_directory(SmallVectorImpl<char> &result);
319
320/// @brief Has root name?
321///
322/// root_name != ""
323///
324/// @param path Input path.
325/// @result True if the path has a root name, false otherwise.
326bool has_root_name(const Twine &path);
327
328/// @brief Has root directory?
329///
330/// root_directory != ""
331///
332/// @param path Input path.
333/// @result True if the path has a root directory, false otherwise.
334bool has_root_directory(const Twine &path);
335
336/// @brief Has root path?
337///
338/// root_path != ""
339///
340/// @param path Input path.
341/// @result True if the path has a root path, false otherwise.
342bool has_root_path(const Twine &path);
343
344/// @brief Has relative path?
345///
346/// relative_path != ""
347///
348/// @param path Input path.
349/// @result True if the path has a relative path, false otherwise.
350bool has_relative_path(const Twine &path);
351
352/// @brief Has parent path?
353///
354/// parent_path != ""
355///
356/// @param path Input path.
357/// @result True if the path has a parent path, false otherwise.
358bool has_parent_path(const Twine &path);
359
360/// @brief Has filename?
361///
362/// filename != ""
363///
364/// @param path Input path.
365/// @result True if the path has a filename, false otherwise.
366bool has_filename(const Twine &path);
367
368/// @brief Has stem?
369///
370/// stem != ""
371///
372/// @param path Input path.
373/// @result True if the path has a stem, false otherwise.
374bool has_stem(const Twine &path);
375
376/// @brief Has extension?
377///
378/// extension != ""
379///
380/// @param path Input path.
381/// @result True if the path has a extension, false otherwise.
382bool has_extension(const Twine &path);
383
384/// @brief Is path absolute?
385///
386/// @param path Input path.
387/// @result True if the path is absolute, false if it is not.
388bool is_absolute(const Twine &path);
389
390/// @brief Is path relative?
391///
392/// @param path Input path.
393/// @result True if the path is relative, false if it is not.
394bool is_relative(const Twine &path);
395
396} // end namespace path
397} // end namespace sys
398} // end namespace llvm
399
400#endif
401