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