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; ///< The iterators current position within Path.
58 Style S; ///< 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; ///< The iterators current position within Path.
84 Style S; ///< 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/// @code
125/// directory/filename.cpp => directory/
126/// directory/ => directory
127/// filename.cpp => <empty>
128/// / => /
129/// @endcode
130///
131/// @param path A path that is modified to not have a file component.
132void remove_filename(SmallVectorImpl<char> &path, Style style = Style::native);
133
134/// Replace the file extension of \a path with \a extension.
135///
136/// @code
137/// ./filename.cpp => ./filename.extension
138/// ./filename => ./filename.extension
139/// ./ => ./.extension
140/// @endcode
141///
142/// @param path A path that has its extension replaced with \a extension.
143/// @param extension The extension to be added. It may be empty. It may also
144/// optionally start with a '.', if it does not, one will be
145/// prepended.
146void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,
147 Style style = Style::native);
148
149/// Replace matching path prefix with another path.
150///
151/// @code
152/// /foo, /old, /new => /foo
153/// /old/foo, /old, /new => /new/foo
154/// /foo, <empty>, /new => /new/foo
155/// /old/foo, /old, <empty> => /foo
156/// @endcode
157///
158/// @param Path If \a Path starts with \a OldPrefix modify to instead
159/// start with \a NewPrefix.
160/// @param OldPrefix The path prefix to strip from \a Path.
161/// @param NewPrefix The path prefix to replace \a NewPrefix with.
162void replace_path_prefix(SmallVectorImpl<char> &Path,
163 const StringRef &OldPrefix, const StringRef &NewPrefix,
164 Style style = Style::native);
165
166/// Append to path.
167///
168/// @code
169/// /foo + bar/f => /foo/bar/f
170/// /foo/ + bar/f => /foo/bar/f
171/// foo + bar/f => foo/bar/f
172/// @endcode
173///
174/// @param path Set to \a path + \a component.
175/// @param a The component to be appended to \a path.
176void append(SmallVectorImpl<char> &path, const Twine &a,
177 const Twine &b = "",
178 const Twine &c = "",
179 const Twine &d = "");
180
181void append(SmallVectorImpl<char> &path, Style style, const Twine &a,
182 const Twine &b = "", const Twine &c = "", const Twine &d = "");
183
184/// Append to path.
185///
186/// @code
187/// /foo + [bar,f] => /foo/bar/f
188/// /foo/ + [bar,f] => /foo/bar/f
189/// foo + [bar,f] => foo/bar/f
190/// @endcode
191///
192/// @param path Set to \a path + [\a begin, \a end).
193/// @param begin Start of components to append.
194/// @param end One past the end of components to append.
195void append(SmallVectorImpl<char> &path, const_iterator begin,
196 const_iterator end, Style style = Style::native);
197
198/// @}
199/// @name Transforms (or some other better name)
200/// @{
201
202/// Convert path to the native form. This is used to give paths to users and
203/// operating system calls in the platform's normal way. For example, on Windows
204/// all '/' are converted to '\'.
205///
206/// @param path A path that is transformed to native format.
207/// @param result Holds the result of the transformation.
208void native(const Twine &path, SmallVectorImpl<char> &result,
209 Style style = Style::native);
210
211/// Convert path to the native form in place. This is used to give paths to
212/// users and operating system calls in the platform's normal way. For example,
213/// on Windows all '/' are converted to '\'.
214///
215/// @param path A path that is transformed to native format.
216void native(SmallVectorImpl<char> &path, Style style = Style::native);
217
218/// Replaces backslashes with slashes if Windows.
219///
220/// @param path processed path
221/// @result The result of replacing backslashes with forward slashes if Windows.
222/// On Unix, this function is a no-op because backslashes are valid path
223/// chracters.
224std::string convert_to_slash(StringRef path, Style style = Style::native);
225
226/// @}
227/// @name Lexical Observers
228/// @{
229
230/// Get root name.
231///
232/// @code
233/// //net/hello => //net
234/// c:/hello => c: (on Windows, on other platforms nothing)
235/// /hello => <empty>
236/// @endcode
237///
238/// @param path Input path.
239/// @result The root name of \a path if it has one, otherwise "".
240StringRef root_name(StringRef path, Style style = Style::native);
241
242/// Get root directory.
243///
244/// @code
245/// /goo/hello => /
246/// c:/hello => /
247/// d/file.txt => <empty>
248/// @endcode
249///
250/// @param path Input path.
251/// @result The root directory of \a path if it has one, otherwise
252/// "".
253StringRef root_directory(StringRef path, Style style = Style::native);
254
255/// Get root path.
256///
257/// Equivalent to root_name + root_directory.
258///
259/// @param path Input path.
260/// @result The root path of \a path if it has one, otherwise "".
261StringRef root_path(StringRef path, Style style = Style::native);
262
263/// Get relative path.
264///
265/// @code
266/// C:\hello\world => hello\world
267/// foo/bar => foo/bar
268/// /foo/bar => foo/bar
269/// @endcode
270///
271/// @param path Input path.
272/// @result The path starting after root_path if one exists, otherwise "".
273StringRef relative_path(StringRef path, Style style = Style::native);
274
275/// Get parent path.
276///
277/// @code
278/// / => <empty>
279/// /foo => /
280/// foo/../bar => foo/..
281/// @endcode
282///
283/// @param path Input path.
284/// @result The parent path of \a path if one exists, otherwise "".
285StringRef parent_path(StringRef path, Style style = Style::native);
286
287/// Get filename.
288///
289/// @code
290/// /foo.txt => foo.txt
291/// . => .
292/// .. => ..
293/// / => /
294/// @endcode
295///
296/// @param path Input path.
297/// @result The filename part of \a path. This is defined as the last component
298/// of \a path.
299StringRef filename(StringRef path, Style style = Style::native);
300
301/// Get stem.
302///
303/// If filename contains a dot but not solely one or two dots, result is the
304/// substring of filename ending at (but not including) the last dot. Otherwise
305/// it is filename.
306///
307/// @code
308/// /foo/bar.txt => bar
309/// /foo/bar => bar
310/// /foo/.txt => <empty>
311/// /foo/. => .
312/// /foo/.. => ..
313/// @endcode
314///
315/// @param path Input path.
316/// @result The stem of \a path.
317StringRef stem(StringRef path, Style style = Style::native);
318
319/// Get extension.
320///
321/// If filename contains a dot but not solely one or two dots, result is the
322/// substring of filename starting at (and including) the last dot, and ending
323/// at the end of \a path. Otherwise "".
324///
325/// @code
326/// /foo/bar.txt => .txt
327/// /foo/bar => <empty>
328/// /foo/.txt => .txt
329/// @endcode
330///
331/// @param path Input path.
332/// @result The extension of \a path.
333StringRef extension(StringRef path, Style style = Style::native);
334
335/// Check whether the given char is a path separator on the host OS.
336///
337/// @param value a character
338/// @result true if \a value is a path separator character on the host OS
339bool is_separator(char value, Style style = Style::native);
340
341/// Return the preferred separator for this platform.
342///
343/// @result StringRef of the preferred separator, null-terminated.
344StringRef get_separator(Style style = Style::native);
345
346/// Get the typical temporary directory for the system, e.g.,
347/// "/var/tmp" or "C:/TEMP"
348///
349/// @param erasedOnReboot Whether to favor a path that is erased on reboot
350/// rather than one that potentially persists longer. This parameter will be
351/// ignored if the user or system has set the typical environment variable
352/// (e.g., TEMP on Windows, TMPDIR on *nix) to specify a temporary directory.
353///
354/// @param result Holds the resulting path name.
355void system_temp_directory(bool erasedOnReboot, SmallVectorImpl<char> &result);
356
357/// Get the user's home directory.
358///
359/// @param result Holds the resulting path name.
360/// @result True if a home directory is set, false otherwise.
361bool home_directory(SmallVectorImpl<char> &result);
362
363/// Has root name?
364///
365/// root_name != ""
366///
367/// @param path Input path.
368/// @result True if the path has a root name, false otherwise.
369bool has_root_name(const Twine &path, Style style = Style::native);
370
371/// Has root directory?
372///
373/// root_directory != ""
374///
375/// @param path Input path.
376/// @result True if the path has a root directory, false otherwise.
377bool has_root_directory(const Twine &path, Style style = Style::native);
378
379/// Has root path?
380///
381/// root_path != ""
382///
383/// @param path Input path.
384/// @result True if the path has a root path, false otherwise.
385bool has_root_path(const Twine &path, Style style = Style::native);
386
387/// Has relative path?
388///
389/// relative_path != ""
390///
391/// @param path Input path.
392/// @result True if the path has a relative path, false otherwise.
393bool has_relative_path(const Twine &path, Style style = Style::native);
394
395/// Has parent path?
396///
397/// parent_path != ""
398///
399/// @param path Input path.
400/// @result True if the path has a parent path, false otherwise.
401bool has_parent_path(const Twine &path, Style style = Style::native);
402
403/// Has filename?
404///
405/// filename != ""
406///
407/// @param path Input path.
408/// @result True if the path has a filename, false otherwise.
409bool has_filename(const Twine &path, Style style = Style::native);
410
411/// Has stem?
412///
413/// stem != ""
414///
415/// @param path Input path.
416/// @result True if the path has a stem, false otherwise.
417bool has_stem(const Twine &path, Style style = Style::native);
418
419/// Has extension?
420///
421/// extension != ""
422///
423/// @param path Input path.
424/// @result True if the path has a extension, false otherwise.
425bool has_extension(const Twine &path, Style style = Style::native);
426
427/// Is path absolute?
428///
429/// @param path Input path.
430/// @result True if the path is absolute, false if it is not.
431bool is_absolute(const Twine &path, Style style = Style::native);
432
433/// Is path relative?
434///
435/// @param path Input path.
436/// @result True if the path is relative, false if it is not.
437bool is_relative(const Twine &path, Style style = Style::native);
438
439/// Remove redundant leading "./" pieces and consecutive separators.
440///
441/// @param path Input path.
442/// @result The cleaned-up \a path.
443StringRef remove_leading_dotslash(StringRef path, Style style = Style::native);
444
445/// In-place remove any './' and optionally '../' components from a path.
446///
447/// @param path processed path
448/// @param remove_dot_dot specify if '../' (except for leading "../") should be
449/// removed
450/// @result True if path was changed
451bool remove_dots(SmallVectorImpl<char> &path, bool remove_dot_dot = false,
452 Style style = Style::native);
453
454#if defined(_WIN32)
455std::error_code widenPath(const Twine &Path8, SmallVectorImpl<wchar_t> &Path16);
456#endif
457
458} // end namespace path
459} // end namespace sys
460} // end namespace llvm
461
462#endif
463