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/// @}
177/// @name Lexical Observers
178/// @{
179
180/// @brief Get root name.
181///
182/// @code
183///   //net/hello => //net
184///   c:/hello    => c: (on Windows, on other platforms nothing)
185///   /hello      => <empty>
186/// @endcode
187///
188/// @param path Input path.
189/// @result The root name of \a path if it has one, otherwise "".
190const StringRef root_name(StringRef path);
191
192/// @brief Get root directory.
193///
194/// @code
195///   /goo/hello => /
196///   c:/hello   => /
197///   d/file.txt => <empty>
198/// @endcode
199///
200/// @param path Input path.
201/// @result The root directory of \a path if it has one, otherwise
202///               "".
203const StringRef root_directory(StringRef path);
204
205/// @brief Get root path.
206///
207/// Equivalent to root_name + root_directory.
208///
209/// @param path Input path.
210/// @result The root path of \a path if it has one, otherwise "".
211const StringRef root_path(StringRef path);
212
213/// @brief Get relative path.
214///
215/// @code
216///   C:\hello\world => hello\world
217///   foo/bar        => foo/bar
218///   /foo/bar       => foo/bar
219/// @endcode
220///
221/// @param path Input path.
222/// @result The path starting after root_path if one exists, otherwise "".
223const StringRef relative_path(StringRef path);
224
225/// @brief Get parent path.
226///
227/// @code
228///   /          => <empty>
229///   /foo       => /
230///   foo/../bar => foo/..
231/// @endcode
232///
233/// @param path Input path.
234/// @result The parent path of \a path if one exists, otherwise "".
235const StringRef parent_path(StringRef path);
236
237/// @brief Get filename.
238///
239/// @code
240///   /foo.txt    => foo.txt
241///   .          => .
242///   ..         => ..
243///   /          => /
244/// @endcode
245///
246/// @param path Input path.
247/// @result The filename part of \a path. This is defined as the last component
248///         of \a path.
249const StringRef filename(StringRef path);
250
251/// @brief Get stem.
252///
253/// If filename contains a dot but not solely one or two dots, result is the
254/// substring of filename ending at (but not including) the last dot. Otherwise
255/// it is filename.
256///
257/// @code
258///   /foo/bar.txt => bar
259///   /foo/bar     => bar
260///   /foo/.txt    => <empty>
261///   /foo/.       => .
262///   /foo/..      => ..
263/// @endcode
264///
265/// @param path Input path.
266/// @result The stem of \a path.
267const StringRef stem(StringRef path);
268
269/// @brief Get extension.
270///
271/// If filename contains a dot but not solely one or two dots, result is the
272/// substring of filename starting at (and including) the last dot, and ending
273/// at the end of \a path. Otherwise "".
274///
275/// @code
276///   /foo/bar.txt => .txt
277///   /foo/bar     => <empty>
278///   /foo/.txt    => .txt
279/// @endcode
280///
281/// @param path Input path.
282/// @result The extension of \a path.
283const StringRef extension(StringRef path);
284
285/// @brief Check whether the given char is a path separator on the host OS.
286///
287/// @param value a character
288/// @result true if \a value is a path separator character on the host OS
289bool is_separator(char value);
290
291/// @brief Get the typical temporary directory for the system, e.g.,
292/// "/var/tmp" or "C:/TEMP"
293///
294/// @param erasedOnReboot Whether to favor a path that is erased on reboot
295/// rather than one that potentially persists longer. This parameter will be
296/// ignored if the user or system has set the typical environment variable
297/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
298///
299/// @param result Holds the resulting path name.
300void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
301
302/// @brief Has root name?
303///
304/// root_name != ""
305///
306/// @param path Input path.
307/// @result True if the path has a root name, false otherwise.
308bool has_root_name(const Twine &path);
309
310/// @brief Has root directory?
311///
312/// root_directory != ""
313///
314/// @param path Input path.
315/// @result True if the path has a root directory, false otherwise.
316bool has_root_directory(const Twine &path);
317
318/// @brief Has root path?
319///
320/// root_path != ""
321///
322/// @param path Input path.
323/// @result True if the path has a root path, false otherwise.
324bool has_root_path(const Twine &path);
325
326/// @brief Has relative path?
327///
328/// relative_path != ""
329///
330/// @param path Input path.
331/// @result True if the path has a relative path, false otherwise.
332bool has_relative_path(const Twine &path);
333
334/// @brief Has parent path?
335///
336/// parent_path != ""
337///
338/// @param path Input path.
339/// @result True if the path has a parent path, false otherwise.
340bool has_parent_path(const Twine &path);
341
342/// @brief Has filename?
343///
344/// filename != ""
345///
346/// @param path Input path.
347/// @result True if the path has a filename, false otherwise.
348bool has_filename(const Twine &path);
349
350/// @brief Has stem?
351///
352/// stem != ""
353///
354/// @param path Input path.
355/// @result True if the path has a stem, false otherwise.
356bool has_stem(const Twine &path);
357
358/// @brief Has extension?
359///
360/// extension != ""
361///
362/// @param path Input path.
363/// @result True if the path has a extension, false otherwise.
364bool has_extension(const Twine &path);
365
366/// @brief Is path absolute?
367///
368/// @param path Input path.
369/// @result True if the path is absolute, false if it is not.
370bool is_absolute(const Twine &path);
371
372/// @brief Is path relative?
373///
374/// @param path Input path.
375/// @result True if the path is relative, false if it is not.
376bool is_relative(const Twine &path);
377
378} // end namespace path
379} // end namespace sys
380} // end namespace llvm
381
382#endif
383