1//===-- Path.cpp - Implement OS Path Concept ------------------------------===//
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 implements the operating system Path API.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/Support/Path.h"
14#include "llvm/ADT/ArrayRef.h"
15#include "llvm/ADT/ScopeExit.h"
16#include "llvm/ADT/StringExtras.h"
17#include "llvm/Config/config.h"
18#include "llvm/Config/llvm-config.h"
19#include "llvm/Support/Endian.h"
20#include "llvm/Support/Errc.h"
21#include "llvm/Support/ErrorHandling.h"
22#include "llvm/Support/FileSystem.h"
23#include "llvm/Support/Process.h"
24#include "llvm/Support/Signals.h"
25#include <cctype>
26#include <cerrno>
27
28#if !defined(_MSC_VER) && !defined(__MINGW32__)
29#include <unistd.h>
30#else
31#include <io.h>
32#endif
33
34using namespace llvm;
35using namespace llvm::support::endian;
36
37namespace {
38 using llvm::StringRef;
39 using llvm::sys::path::is_separator;
40 using llvm::sys::path::Style;
41
42 inline Style real_style(Style style) {
43 if (style != Style::native)
44 return style;
45 if (is_style_posix(S: style))
46 return Style::posix;
47 return LLVM_WINDOWS_PREFER_FORWARD_SLASH ? Style::windows_slash
48 : Style::windows_backslash;
49 }
50
51 inline const char *separators(Style style) {
52 if (is_style_windows(S: style))
53 return "\\/";
54 return "/";
55 }
56
57 inline char preferred_separator(Style style) {
58 if (real_style(style) == Style::windows)
59 return '\\';
60 return '/';
61 }
62
63 StringRef find_first_component(StringRef path, Style style) {
64 // Look for this first component in the following order.
65 // * empty (in this case we return an empty string)
66 // * either C: or {//,\\}net.
67 // * {/,\}
68 // * {file,directory}name
69
70 if (path.empty())
71 return path;
72
73 if (is_style_windows(S: style)) {
74 // C:
75 if (path.size() >= 2 &&
76 std::isalpha(static_cast<unsigned char>(path[0])) && path[1] == ':')
77 return path.substr(Start: 0, N: 2);
78 }
79
80 // //net
81 if ((path.size() > 2) && is_separator(value: path[0], style) &&
82 path[0] == path[1] && !is_separator(value: path[2], style)) {
83 // Find the next directory separator.
84 size_t end = path.find_first_of(Chars: separators(style), From: 2);
85 return path.substr(Start: 0, N: end);
86 }
87
88 // {/,\}
89 if (is_separator(value: path[0], style))
90 return path.substr(Start: 0, N: 1);
91
92 // * {file,directory}name
93 size_t end = path.find_first_of(Chars: separators(style));
94 return path.substr(Start: 0, N: end);
95 }
96
97 // Returns the first character of the filename in str. For paths ending in
98 // '/', it returns the position of the '/'.
99 size_t filename_pos(StringRef str, Style style) {
100 if (str.size() > 0 && is_separator(value: str[str.size() - 1], style))
101 return str.size() - 1;
102
103 size_t pos = str.find_last_of(Chars: separators(style), From: str.size() - 1);
104
105 if (is_style_windows(S: style)) {
106 if (pos == StringRef::npos)
107 pos = str.find_last_of(C: ':', From: str.size() - 1);
108 }
109
110 if (pos == StringRef::npos || (pos == 1 && is_separator(value: str[0], style)))
111 return 0;
112
113 return pos + 1;
114 }
115
116 // Returns the position of the root directory in str. If there is no root
117 // directory in str, it returns StringRef::npos.
118 size_t root_dir_start(StringRef str, Style style) {
119 // case "c:/"
120 if (is_style_windows(S: style)) {
121 if (str.size() > 2 && str[1] == ':' && is_separator(value: str[2], style))
122 return 2;
123 }
124
125 // case "//net"
126 if (str.size() > 3 && is_separator(value: str[0], style) && str[0] == str[1] &&
127 !is_separator(value: str[2], style)) {
128 return str.find_first_of(Chars: separators(style), From: 2);
129 }
130
131 // case "/"
132 if (str.size() > 0 && is_separator(value: str[0], style))
133 return 0;
134
135 return StringRef::npos;
136 }
137
138 // Returns the position past the end of the "parent path" of path. The parent
139 // path will not end in '/', unless the parent is the root directory. If the
140 // path has no parent, 0 is returned.
141 size_t parent_path_end(StringRef path, Style style) {
142 size_t end_pos = filename_pos(str: path, style);
143
144 bool filename_was_sep =
145 path.size() > 0 && is_separator(value: path[end_pos], style);
146
147 // Skip separators until we reach root dir (or the start of the string).
148 size_t root_dir_pos = root_dir_start(str: path, style);
149 while (end_pos > 0 &&
150 (root_dir_pos == StringRef::npos || end_pos > root_dir_pos) &&
151 is_separator(value: path[end_pos - 1], style))
152 --end_pos;
153
154 if (end_pos == root_dir_pos && !filename_was_sep) {
155 // We've reached the root dir and the input path was *not* ending in a
156 // sequence of slashes. Include the root dir in the parent path.
157 return root_dir_pos + 1;
158 }
159
160 // Otherwise, just include before the last slash.
161 return end_pos;
162 }
163} // end unnamed namespace
164
165enum FSEntity {
166 FS_Dir,
167 FS_File,
168 FS_Name
169};
170
171static std::error_code
172createUniqueEntity(const Twine &Model, int &ResultFD,
173 SmallVectorImpl<char> &ResultPath, bool MakeAbsolute,
174 FSEntity Type, sys::fs::OpenFlags Flags = sys::fs::OF_None,
175 unsigned Mode = 0) {
176
177 // Limit the number of attempts we make, so that we don't infinite loop. E.g.
178 // "permission denied" could be for a specific file (so we retry with a
179 // different name) or for the whole directory (retry would always fail).
180 // Checking which is racy, so we try a number of times, then give up.
181 std::error_code EC;
182 for (int Retries = 128; Retries > 0; --Retries) {
183 sys::fs::createUniquePath(Model, ResultPath, MakeAbsolute);
184 // Try to open + create the file.
185 switch (Type) {
186 case FS_File: {
187 EC = sys::fs::openFileForReadWrite(Name: Twine(ResultPath.begin()), ResultFD,
188 Disp: sys::fs::CD_CreateNew, Flags, Mode);
189 if (EC) {
190 // errc::permission_denied happens on Windows when we try to open a file
191 // that has been marked for deletion.
192 if (EC == errc::file_exists || EC == errc::permission_denied)
193 continue;
194 return EC;
195 }
196
197 return std::error_code();
198 }
199
200 case FS_Name: {
201 EC = sys::fs::access(Path: ResultPath.begin(), Mode: sys::fs::AccessMode::Exist);
202 if (EC == errc::no_such_file_or_directory)
203 return std::error_code();
204 if (EC)
205 return EC;
206 continue;
207 }
208
209 case FS_Dir: {
210 EC = sys::fs::create_directory(path: ResultPath.begin(), IgnoreExisting: false);
211 if (EC) {
212 if (EC == errc::file_exists)
213 continue;
214 return EC;
215 }
216 return std::error_code();
217 }
218 }
219 llvm_unreachable("Invalid Type");
220 }
221 return EC;
222}
223
224namespace llvm {
225namespace sys {
226namespace path {
227
228const_iterator begin(StringRef path, Style style) {
229 const_iterator i;
230 i.Path = path;
231 i.Component = find_first_component(path, style);
232 i.Position = 0;
233 i.S = style;
234 return i;
235}
236
237const_iterator end(StringRef path) {
238 const_iterator i;
239 i.Path = path;
240 i.Position = path.size();
241 return i;
242}
243
244const_iterator &const_iterator::operator++() {
245 assert(Position < Path.size() && "Tried to increment past end!");
246
247 // Increment Position to past the current component
248 Position += Component.size();
249
250 // Check for end.
251 if (Position == Path.size()) {
252 Component = StringRef();
253 return *this;
254 }
255
256 // Both POSIX and Windows treat paths that begin with exactly two separators
257 // specially.
258 bool was_net = Component.size() > 2 && is_separator(value: Component[0], style: S) &&
259 Component[1] == Component[0] && !is_separator(value: Component[2], style: S);
260
261 // Handle separators.
262 if (is_separator(value: Path[Position], style: S)) {
263 // Root dir.
264 if (was_net ||
265 // c:/
266 (is_style_windows(S) && Component.ends_with(Suffix: ":"))) {
267 Component = Path.substr(Start: Position, N: 1);
268 return *this;
269 }
270
271 // Skip extra separators.
272 while (Position != Path.size() && is_separator(value: Path[Position], style: S)) {
273 ++Position;
274 }
275
276 // Treat trailing '/' as a '.', unless it is the root dir.
277 if (Position == Path.size() && Component != "/") {
278 --Position;
279 Component = ".";
280 return *this;
281 }
282 }
283
284 // Find next component.
285 size_t end_pos = Path.find_first_of(Chars: separators(style: S), From: Position);
286 Component = Path.slice(Start: Position, End: end_pos);
287
288 return *this;
289}
290
291bool const_iterator::operator==(const const_iterator &RHS) const {
292 return Path.begin() == RHS.Path.begin() && Position == RHS.Position;
293}
294
295ptrdiff_t const_iterator::operator-(const const_iterator &RHS) const {
296 return Position - RHS.Position;
297}
298
299reverse_iterator rbegin(StringRef Path, Style style) {
300 reverse_iterator I;
301 I.Path = Path;
302 I.Position = Path.size();
303 I.S = style;
304 ++I;
305 return I;
306}
307
308reverse_iterator rend(StringRef Path) {
309 reverse_iterator I;
310 I.Path = Path;
311 I.Component = Path.substr(Start: 0, N: 0);
312 I.Position = 0;
313 return I;
314}
315
316reverse_iterator &reverse_iterator::operator++() {
317 size_t root_dir_pos = root_dir_start(str: Path, style: S);
318
319 // Skip separators unless it's the root directory.
320 size_t end_pos = Position;
321 while (end_pos > 0 && (end_pos - 1) != root_dir_pos &&
322 is_separator(value: Path[end_pos - 1], style: S))
323 --end_pos;
324
325 // Treat trailing '/' as a '.', unless it is the root dir.
326 if (Position == Path.size() && !Path.empty() &&
327 is_separator(value: Path.back(), style: S) &&
328 (root_dir_pos == StringRef::npos || end_pos - 1 > root_dir_pos)) {
329 --Position;
330 Component = ".";
331 return *this;
332 }
333
334 // Find next separator.
335 size_t start_pos = filename_pos(str: Path.substr(Start: 0, N: end_pos), style: S);
336 Component = Path.slice(Start: start_pos, End: end_pos);
337 Position = start_pos;
338 return *this;
339}
340
341bool reverse_iterator::operator==(const reverse_iterator &RHS) const {
342 return Path.begin() == RHS.Path.begin() && Component == RHS.Component &&
343 Position == RHS.Position;
344}
345
346ptrdiff_t reverse_iterator::operator-(const reverse_iterator &RHS) const {
347 return Position - RHS.Position;
348}
349
350StringRef root_path(StringRef path, Style style) {
351 const_iterator b = begin(path, style), pos = b, e = end(path);
352 if (b != e) {
353 bool has_net =
354 b->size() > 2 && is_separator(value: (*b)[0], style) && (*b)[1] == (*b)[0];
355 bool has_drive = is_style_windows(S: style) && b->ends_with(Suffix: ":");
356
357 if (has_net || has_drive) {
358 if ((++pos != e) && is_separator(value: (*pos)[0], style)) {
359 // {C:/,//net/}, so get the first two components.
360 return path.substr(Start: 0, N: b->size() + pos->size());
361 }
362 // just {C:,//net}, return the first component.
363 return *b;
364 }
365
366 // POSIX style root directory.
367 if (is_separator(value: (*b)[0], style)) {
368 return *b;
369 }
370 }
371
372 return StringRef();
373}
374
375StringRef root_name(StringRef path, Style style) {
376 const_iterator b = begin(path, style), e = end(path);
377 if (b != e) {
378 bool has_net =
379 b->size() > 2 && is_separator(value: (*b)[0], style) && (*b)[1] == (*b)[0];
380 bool has_drive = is_style_windows(S: style) && b->ends_with(Suffix: ":");
381
382 if (has_net || has_drive) {
383 // just {C:,//net}, return the first component.
384 return *b;
385 }
386 }
387
388 // No path or no name.
389 return StringRef();
390}
391
392StringRef root_directory(StringRef path, Style style) {
393 const_iterator b = begin(path, style), pos = b, e = end(path);
394 if (b != e) {
395 bool has_net =
396 b->size() > 2 && is_separator(value: (*b)[0], style) && (*b)[1] == (*b)[0];
397 bool has_drive = is_style_windows(S: style) && b->ends_with(Suffix: ":");
398
399 if ((has_net || has_drive) &&
400 // {C:,//net}, skip to the next component.
401 (++pos != e) && is_separator(value: (*pos)[0], style)) {
402 return *pos;
403 }
404
405 // POSIX style root directory.
406 if (!has_net && is_separator(value: (*b)[0], style)) {
407 return *b;
408 }
409 }
410
411 // No path or no root.
412 return StringRef();
413}
414
415StringRef relative_path(StringRef path, Style style) {
416 StringRef root = root_path(path, style);
417 return path.substr(Start: root.size());
418}
419
420void append(SmallVectorImpl<char> &path, Style style, const Twine &a,
421 const Twine &b, const Twine &c, const Twine &d) {
422 SmallString<32> a_storage;
423 SmallString<32> b_storage;
424 SmallString<32> c_storage;
425 SmallString<32> d_storage;
426
427 SmallVector<StringRef, 4> components;
428 if (!a.isTriviallyEmpty()) components.push_back(Elt: a.toStringRef(Out&: a_storage));
429 if (!b.isTriviallyEmpty()) components.push_back(Elt: b.toStringRef(Out&: b_storage));
430 if (!c.isTriviallyEmpty()) components.push_back(Elt: c.toStringRef(Out&: c_storage));
431 if (!d.isTriviallyEmpty()) components.push_back(Elt: d.toStringRef(Out&: d_storage));
432
433 for (auto &component : components) {
434 bool path_has_sep =
435 !path.empty() && is_separator(value: path[path.size() - 1], style);
436 if (path_has_sep) {
437 // Strip separators from beginning of component.
438 size_t loc = component.find_first_not_of(Chars: separators(style));
439 StringRef c = component.substr(Start: loc);
440
441 // Append it.
442 path.append(in_start: c.begin(), in_end: c.end());
443 continue;
444 }
445
446 bool component_has_sep =
447 !component.empty() && is_separator(value: component[0], style);
448 if (!component_has_sep &&
449 !(path.empty() || has_root_name(path: component, style))) {
450 // Add a separator.
451 path.push_back(Elt: preferred_separator(style));
452 }
453
454 path.append(in_start: component.begin(), in_end: component.end());
455 }
456}
457
458void append(SmallVectorImpl<char> &path, const Twine &a, const Twine &b,
459 const Twine &c, const Twine &d) {
460 append(path, style: Style::native, a, b, c, d);
461}
462
463void append(SmallVectorImpl<char> &path, const_iterator begin,
464 const_iterator end, Style style) {
465 for (; begin != end; ++begin)
466 path::append(path, style, a: *begin);
467}
468
469StringRef parent_path(StringRef path, Style style) {
470 size_t end_pos = parent_path_end(path, style);
471 if (end_pos == StringRef::npos)
472 return StringRef();
473 return path.substr(Start: 0, N: end_pos);
474}
475
476void remove_filename(SmallVectorImpl<char> &path, Style style) {
477 size_t end_pos = parent_path_end(path: StringRef(path.begin(), path.size()), style);
478 if (end_pos != StringRef::npos)
479 path.truncate(N: end_pos);
480}
481
482void replace_extension(SmallVectorImpl<char> &path, const Twine &extension,
483 Style style) {
484 StringRef p(path.begin(), path.size());
485 SmallString<32> ext_storage;
486 StringRef ext = extension.toStringRef(Out&: ext_storage);
487
488 // Erase existing extension.
489 size_t pos = p.find_last_of(C: '.');
490 if (pos != StringRef::npos && pos >= filename_pos(str: p, style))
491 path.truncate(N: pos);
492
493 // Append '.' if needed.
494 if (ext.size() > 0 && ext[0] != '.')
495 path.push_back(Elt: '.');
496
497 // Append extension.
498 path.append(in_start: ext.begin(), in_end: ext.end());
499}
500
501static bool starts_with(StringRef Path, StringRef Prefix,
502 Style style = Style::native) {
503 // Windows prefix matching : case and separator insensitive
504 if (is_style_windows(S: style)) {
505 if (Path.size() < Prefix.size())
506 return false;
507 for (size_t I = 0, E = Prefix.size(); I != E; ++I) {
508 bool SepPath = is_separator(value: Path[I], style);
509 bool SepPrefix = is_separator(value: Prefix[I], style);
510 if (SepPath != SepPrefix)
511 return false;
512 if (!SepPath && toLower(x: Path[I]) != toLower(x: Prefix[I]))
513 return false;
514 }
515 return true;
516 }
517 return Path.starts_with(Prefix);
518}
519
520bool replace_path_prefix(SmallVectorImpl<char> &Path, StringRef OldPrefix,
521 StringRef NewPrefix, Style style) {
522 if (OldPrefix.empty() && NewPrefix.empty())
523 return false;
524
525 StringRef OrigPath(Path.begin(), Path.size());
526 if (!starts_with(Path: OrigPath, Prefix: OldPrefix, style))
527 return false;
528
529 // If prefixes have the same size we can simply copy the new one over.
530 if (OldPrefix.size() == NewPrefix.size()) {
531 llvm::copy(Range&: NewPrefix, Out: Path.begin());
532 return true;
533 }
534
535 StringRef RelPath = OrigPath.substr(Start: OldPrefix.size());
536 SmallString<256> NewPath;
537 (Twine(NewPrefix) + RelPath).toVector(Out&: NewPath);
538 Path.swap(RHS&: NewPath);
539 return true;
540}
541
542void native(const Twine &path, SmallVectorImpl<char> &result, Style style) {
543 assert((!path.isSingleStringRef() ||
544 path.getSingleStringRef().data() != result.data()) &&
545 "path and result are not allowed to overlap!");
546 // Clear result.
547 result.clear();
548 path.toVector(Out&: result);
549 native(path&: result, style);
550}
551
552void native(SmallVectorImpl<char> &Path, Style style) {
553 if (Path.empty())
554 return;
555 if (is_style_windows(S: style)) {
556 for (char &Ch : Path)
557 if (is_separator(value: Ch, style))
558 Ch = preferred_separator(style);
559 if (Path[0] == '~' && (Path.size() == 1 || is_separator(value: Path[1], style))) {
560 SmallString<128> PathHome;
561 home_directory(result&: PathHome);
562 PathHome.append(in_start: Path.begin() + 1, in_end: Path.end());
563 Path = PathHome;
564 }
565 } else {
566 std::replace(first: Path.begin(), last: Path.end(), old_value: '\\', new_value: '/');
567 }
568}
569
570std::string convert_to_slash(StringRef path, Style style) {
571 if (is_style_posix(S: style))
572 return std::string(path);
573
574 std::string s = path.str();
575 std::replace(first: s.begin(), last: s.end(), old_value: '\\', new_value: '/');
576 return s;
577}
578
579StringRef filename(StringRef path, Style style) { return *rbegin(Path: path, style); }
580
581StringRef stem(StringRef path, Style style) {
582 StringRef fname = filename(path, style);
583 size_t pos = fname.find_last_of(C: '.');
584 if (pos == StringRef::npos)
585 return fname;
586 if ((fname.size() == 1 && fname == ".") ||
587 (fname.size() == 2 && fname == ".."))
588 return fname;
589 return fname.substr(Start: 0, N: pos);
590}
591
592StringRef extension(StringRef path, Style style) {
593 StringRef fname = filename(path, style);
594 size_t pos = fname.find_last_of(C: '.');
595 if (pos == StringRef::npos)
596 return StringRef();
597 if ((fname.size() == 1 && fname == ".") ||
598 (fname.size() == 2 && fname == ".."))
599 return StringRef();
600 return fname.substr(Start: pos);
601}
602
603bool is_separator(char value, Style style) {
604 if (value == '/')
605 return true;
606 if (is_style_windows(S: style))
607 return value == '\\';
608 return false;
609}
610
611StringRef get_separator(Style style) {
612 if (real_style(style) == Style::windows)
613 return "\\";
614 return "/";
615}
616
617bool has_root_name(const Twine &path, Style style) {
618 SmallString<128> path_storage;
619 StringRef p = path.toStringRef(Out&: path_storage);
620
621 return !root_name(path: p, style).empty();
622}
623
624bool has_root_directory(const Twine &path, Style style) {
625 SmallString<128> path_storage;
626 StringRef p = path.toStringRef(Out&: path_storage);
627
628 return !root_directory(path: p, style).empty();
629}
630
631bool has_root_path(const Twine &path, Style style) {
632 SmallString<128> path_storage;
633 StringRef p = path.toStringRef(Out&: path_storage);
634
635 return !root_path(path: p, style).empty();
636}
637
638bool has_relative_path(const Twine &path, Style style) {
639 SmallString<128> path_storage;
640 StringRef p = path.toStringRef(Out&: path_storage);
641
642 return !relative_path(path: p, style).empty();
643}
644
645bool has_filename(const Twine &path, Style style) {
646 SmallString<128> path_storage;
647 StringRef p = path.toStringRef(Out&: path_storage);
648
649 return !filename(path: p, style).empty();
650}
651
652bool has_parent_path(const Twine &path, Style style) {
653 SmallString<128> path_storage;
654 StringRef p = path.toStringRef(Out&: path_storage);
655
656 return !parent_path(path: p, style).empty();
657}
658
659bool has_stem(const Twine &path, Style style) {
660 SmallString<128> path_storage;
661 StringRef p = path.toStringRef(Out&: path_storage);
662
663 return !stem(path: p, style).empty();
664}
665
666bool has_extension(const Twine &path, Style style) {
667 SmallString<128> path_storage;
668 StringRef p = path.toStringRef(Out&: path_storage);
669
670 return !extension(path: p, style).empty();
671}
672
673bool is_absolute(const Twine &path, Style style) {
674 SmallString<128> path_storage;
675 StringRef p = path.toStringRef(Out&: path_storage);
676
677 bool rootDir = has_root_directory(path: p, style);
678 bool rootName = is_style_posix(S: style) || has_root_name(path: p, style);
679
680 return rootDir && rootName;
681}
682
683bool is_absolute_gnu(const Twine &path, Style style) {
684 SmallString<128> path_storage;
685 StringRef p = path.toStringRef(Out&: path_storage);
686
687 // Handle '/' which is absolute for both Windows and POSIX systems.
688 // Handle '\\' on Windows.
689 if (!p.empty() && is_separator(value: p.front(), style))
690 return true;
691
692 if (is_style_windows(S: style)) {
693 // Handle drive letter pattern (a character followed by ':') on Windows.
694 if (p.size() >= 2 && (p[0] && p[1] == ':'))
695 return true;
696 }
697
698 return false;
699}
700
701bool is_relative(const Twine &path, Style style) {
702 return !is_absolute(path, style);
703}
704
705StringRef remove_leading_dotslash(StringRef Path, Style style) {
706 // Remove leading "./" (or ".//" or "././" etc.)
707 while (Path.size() > 2 && Path[0] == '.' && is_separator(value: Path[1], style)) {
708 Path = Path.substr(Start: 2);
709 while (Path.size() > 0 && is_separator(value: Path[0], style))
710 Path = Path.substr(Start: 1);
711 }
712 return Path;
713}
714
715// Remove path traversal components ("." and "..") when possible, and
716// canonicalize slashes.
717bool remove_dots(SmallVectorImpl<char> &the_path, bool remove_dot_dot,
718 Style style) {
719 style = real_style(style);
720 StringRef remaining(the_path.data(), the_path.size());
721 bool needs_change = false;
722 SmallVector<StringRef, 16> components;
723
724 // Consume the root path, if present.
725 StringRef root = path::root_path(path: remaining, style);
726 bool absolute = !root.empty();
727 if (absolute)
728 remaining = remaining.drop_front(N: root.size());
729
730 // Loop over path components manually. This makes it easier to detect
731 // non-preferred slashes and double separators that must be canonicalized.
732 while (!remaining.empty()) {
733 size_t next_slash = remaining.find_first_of(Chars: separators(style));
734 if (next_slash == StringRef::npos)
735 next_slash = remaining.size();
736 StringRef component = remaining.take_front(N: next_slash);
737 remaining = remaining.drop_front(N: next_slash);
738
739 // Eat the slash, and check if it is the preferred separator.
740 if (!remaining.empty()) {
741 needs_change |= remaining.front() != preferred_separator(style);
742 remaining = remaining.drop_front();
743 // The path needs to be rewritten if it has a trailing slash.
744 // FIXME: This is emergent behavior that could be removed.
745 needs_change |= remaining.empty();
746 }
747
748 // Check for path traversal components or double separators.
749 if (component.empty() || component == ".") {
750 needs_change = true;
751 } else if (remove_dot_dot && component == "..") {
752 needs_change = true;
753 // Do not allow ".." to remove the root component. If this is the
754 // beginning of a relative path, keep the ".." component.
755 if (!components.empty() && components.back() != "..") {
756 components.pop_back();
757 } else if (!absolute) {
758 components.push_back(Elt: component);
759 }
760 } else {
761 components.push_back(Elt: component);
762 }
763 }
764
765 SmallString<256> buffer = root;
766 // "root" could be "/", which may need to be translated into "\".
767 make_preferred(path&: buffer, style);
768 needs_change |= root != buffer;
769
770 // Avoid rewriting the path unless we have to.
771 if (!needs_change)
772 return false;
773
774 if (!components.empty()) {
775 buffer += components[0];
776 for (StringRef C : ArrayRef(components).drop_front()) {
777 buffer += preferred_separator(style);
778 buffer += C;
779 }
780 }
781 the_path.swap(RHS&: buffer);
782 return true;
783}
784
785} // end namespace path
786
787namespace fs {
788
789std::error_code getUniqueID(const Twine Path, UniqueID &Result) {
790 file_status Status;
791 std::error_code EC = status(path: Path, result&: Status);
792 if (EC)
793 return EC;
794 Result = Status.getUniqueID();
795 return std::error_code();
796}
797
798void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
799 bool MakeAbsolute) {
800 SmallString<128> ModelStorage;
801 Model.toVector(Out&: ModelStorage);
802
803 if (MakeAbsolute) {
804 // Make model absolute by prepending a temp directory if it's not already.
805 if (!sys::path::is_absolute(path: Twine(ModelStorage))) {
806 SmallString<128> TDir;
807 sys::path::system_temp_directory(erasedOnReboot: true, result&: TDir);
808 sys::path::append(path&: TDir, a: Twine(ModelStorage));
809 ModelStorage.swap(RHS&: TDir);
810 }
811 }
812
813 ResultPath = ModelStorage;
814 ResultPath.push_back(Elt: 0);
815 ResultPath.pop_back();
816
817 // Replace '%' with random chars.
818 for (unsigned i = 0, e = ModelStorage.size(); i != e; ++i) {
819 if (ModelStorage[i] == '%')
820 ResultPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
821 }
822}
823
824std::error_code createUniqueFile(const Twine &Model, int &ResultFd,
825 SmallVectorImpl<char> &ResultPath,
826 OpenFlags Flags, unsigned Mode) {
827 return createUniqueEntity(Model, ResultFD&: ResultFd, ResultPath, MakeAbsolute: false, Type: FS_File, Flags,
828 Mode);
829}
830
831std::error_code createUniqueFile(const Twine &Model,
832 SmallVectorImpl<char> &ResultPath,
833 unsigned Mode) {
834 int FD;
835 auto EC = createUniqueFile(Model, ResultFd&: FD, ResultPath, Flags: OF_None, Mode);
836 if (EC)
837 return EC;
838 // FD is only needed to avoid race conditions. Close it right away.
839 close(fd: FD);
840 return EC;
841}
842
843static std::error_code
844createTemporaryFile(const Twine &Model, int &ResultFD,
845 llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type,
846 sys::fs::OpenFlags Flags = sys::fs::OF_None) {
847 SmallString<128> Storage;
848 StringRef P = Model.toNullTerminatedStringRef(Out&: Storage);
849 assert(P.find_first_of(separators(Style::native)) == StringRef::npos &&
850 "Model must be a simple filename.");
851 // Use P.begin() so that createUniqueEntity doesn't need to recreate Storage.
852 return createUniqueEntity(Model: P.begin(), ResultFD, ResultPath, MakeAbsolute: true, Type, Flags,
853 Mode: owner_read | owner_write);
854}
855
856static std::error_code
857createTemporaryFile(const Twine &Prefix, StringRef Suffix, int &ResultFD,
858 llvm::SmallVectorImpl<char> &ResultPath, FSEntity Type,
859 sys::fs::OpenFlags Flags = sys::fs::OF_None) {
860 const char *Middle = Suffix.empty() ? "-%%%%%%" : "-%%%%%%.";
861 return createTemporaryFile(Model: Prefix + Middle + Suffix, ResultFD, ResultPath,
862 Type, Flags);
863}
864
865std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
866 int &ResultFD,
867 SmallVectorImpl<char> &ResultPath,
868 sys::fs::OpenFlags Flags) {
869 return createTemporaryFile(Prefix, Suffix, ResultFD, ResultPath, Type: FS_File,
870 Flags);
871}
872
873std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
874 SmallVectorImpl<char> &ResultPath,
875 sys::fs::OpenFlags Flags) {
876 int FD;
877 auto EC = createTemporaryFile(Prefix, Suffix, ResultFD&: FD, ResultPath, Flags);
878 if (EC)
879 return EC;
880 // FD is only needed to avoid race conditions. Close it right away.
881 close(fd: FD);
882 return EC;
883}
884
885// This is a mkdtemp with a different pattern. We use createUniqueEntity mostly
886// for consistency. We should try using mkdtemp.
887std::error_code createUniqueDirectory(const Twine &Prefix,
888 SmallVectorImpl<char> &ResultPath) {
889 int Dummy;
890 return createUniqueEntity(Model: Prefix + "-%%%%%%", ResultFD&: Dummy, ResultPath, MakeAbsolute: true,
891 Type: FS_Dir);
892}
893
894std::error_code
895getPotentiallyUniqueFileName(const Twine &Model,
896 SmallVectorImpl<char> &ResultPath) {
897 int Dummy;
898 return createUniqueEntity(Model, ResultFD&: Dummy, ResultPath, MakeAbsolute: false, Type: FS_Name);
899}
900
901std::error_code
902getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,
903 SmallVectorImpl<char> &ResultPath) {
904 int Dummy;
905 return createTemporaryFile(Prefix, Suffix, ResultFD&: Dummy, ResultPath, Type: FS_Name);
906}
907
908void make_absolute(const Twine &current_directory,
909 SmallVectorImpl<char> &path) {
910 StringRef p(path.data(), path.size());
911
912 bool rootDirectory = path::has_root_directory(path: p);
913 bool rootName = path::has_root_name(path: p);
914
915 // Already absolute.
916 if ((rootName || is_style_posix(S: Style::native)) && rootDirectory)
917 return;
918
919 // All of the following conditions will need the current directory.
920 SmallString<128> current_dir;
921 current_directory.toVector(Out&: current_dir);
922
923 // Relative path. Prepend the current directory.
924 if (!rootName && !rootDirectory) {
925 // Append path to the current directory.
926 path::append(path&: current_dir, a: p);
927 // Set path to the result.
928 path.swap(RHS&: current_dir);
929 return;
930 }
931
932 if (!rootName && rootDirectory) {
933 StringRef cdrn = path::root_name(path: current_dir);
934 SmallString<128> curDirRootName(cdrn.begin(), cdrn.end());
935 path::append(path&: curDirRootName, a: p);
936 // Set path to the result.
937 path.swap(RHS&: curDirRootName);
938 return;
939 }
940
941 if (rootName && !rootDirectory) {
942 StringRef pRootName = path::root_name(path: p);
943 StringRef bRootDirectory = path::root_directory(path: current_dir);
944 StringRef bRelativePath = path::relative_path(path: current_dir);
945 StringRef pRelativePath = path::relative_path(path: p);
946
947 SmallString<128> res;
948 path::append(path&: res, a: pRootName, b: bRootDirectory, c: bRelativePath, d: pRelativePath);
949 path.swap(RHS&: res);
950 return;
951 }
952
953 llvm_unreachable("All rootName and rootDirectory combinations should have "
954 "occurred above!");
955}
956
957std::error_code make_absolute(SmallVectorImpl<char> &path) {
958 if (path::is_absolute(path))
959 return {};
960
961 SmallString<128> current_dir;
962 if (std::error_code ec = current_path(result&: current_dir))
963 return ec;
964
965 make_absolute(current_directory: current_dir, path);
966 return {};
967}
968
969std::error_code create_directories(const Twine &Path, bool IgnoreExisting,
970 perms Perms) {
971 SmallString<128> PathStorage;
972 StringRef P = Path.toStringRef(Out&: PathStorage);
973
974 // Be optimistic and try to create the directory
975 std::error_code EC = create_directory(path: P, IgnoreExisting, Perms);
976 // If we succeeded, or had any error other than the parent not existing, just
977 // return it.
978 if (EC != errc::no_such_file_or_directory)
979 return EC;
980
981 // We failed because of a no_such_file_or_directory, try to create the
982 // parent.
983 StringRef Parent = path::parent_path(path: P);
984 if (Parent.empty())
985 return EC;
986
987 if ((EC = create_directories(Path: Parent, IgnoreExisting, Perms)))
988 return EC;
989
990 return create_directory(path: P, IgnoreExisting, Perms);
991}
992
993static std::error_code copy_file_internal(int ReadFD, int WriteFD) {
994 const size_t BufSize = 4096;
995 char *Buf = new char[BufSize];
996 int BytesRead = 0, BytesWritten = 0;
997 for (;;) {
998 BytesRead = read(fd: ReadFD, buf: Buf, nbytes: BufSize);
999 if (BytesRead <= 0)
1000 break;
1001 while (BytesRead) {
1002 BytesWritten = write(fd: WriteFD, buf: Buf, n: BytesRead);
1003 if (BytesWritten < 0)
1004 break;
1005 BytesRead -= BytesWritten;
1006 }
1007 if (BytesWritten < 0)
1008 break;
1009 }
1010 delete[] Buf;
1011
1012 if (BytesRead < 0 || BytesWritten < 0)
1013 return std::error_code(errno, std::generic_category());
1014 return std::error_code();
1015}
1016
1017#ifndef __APPLE__
1018std::error_code copy_file(const Twine &From, const Twine &To) {
1019 int ReadFD, WriteFD;
1020 if (std::error_code EC = openFileForRead(Name: From, ResultFD&: ReadFD, Flags: OF_None))
1021 return EC;
1022 if (std::error_code EC =
1023 openFileForWrite(Name: To, ResultFD&: WriteFD, Disp: CD_CreateAlways, Flags: OF_None)) {
1024 close(fd: ReadFD);
1025 return EC;
1026 }
1027
1028 std::error_code EC = copy_file_internal(ReadFD, WriteFD);
1029
1030 close(fd: ReadFD);
1031 close(fd: WriteFD);
1032
1033 return EC;
1034}
1035#endif
1036
1037std::error_code copy_file(const Twine &From, int ToFD) {
1038 int ReadFD;
1039 if (std::error_code EC = openFileForRead(Name: From, ResultFD&: ReadFD, Flags: OF_None))
1040 return EC;
1041
1042 std::error_code EC = copy_file_internal(ReadFD, WriteFD: ToFD);
1043
1044 close(fd: ReadFD);
1045
1046 return EC;
1047}
1048
1049ErrorOr<MD5::MD5Result> md5_contents(int FD) {
1050 MD5 Hash;
1051
1052 constexpr size_t BufSize = 4096;
1053 std::vector<uint8_t> Buf(BufSize);
1054 int BytesRead = 0;
1055 for (;;) {
1056 BytesRead = read(fd: FD, buf: Buf.data(), nbytes: BufSize);
1057 if (BytesRead <= 0)
1058 break;
1059 Hash.update(Data: ArrayRef(Buf.data(), BytesRead));
1060 }
1061
1062 if (BytesRead < 0)
1063 return std::error_code(errno, std::generic_category());
1064 MD5::MD5Result Result;
1065 Hash.final(Result);
1066 return Result;
1067}
1068
1069ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path) {
1070 int FD;
1071 if (auto EC = openFileForRead(Name: Path, ResultFD&: FD, Flags: OF_None))
1072 return EC;
1073
1074 auto Result = md5_contents(FD);
1075 close(fd: FD);
1076 return Result;
1077}
1078
1079bool exists(const basic_file_status &status) {
1080 return status_known(s: status) && status.type() != file_type::file_not_found;
1081}
1082
1083bool status_known(const basic_file_status &s) {
1084 return s.type() != file_type::status_error;
1085}
1086
1087file_type get_file_type(const Twine &Path, bool Follow) {
1088 file_status st;
1089 if (status(path: Path, result&: st, follow: Follow))
1090 return file_type::status_error;
1091 return st.type();
1092}
1093
1094bool is_directory(const basic_file_status &status) {
1095 return status.type() == file_type::directory_file;
1096}
1097
1098std::error_code is_directory(const Twine &path, bool &result) {
1099 file_status st;
1100 if (std::error_code ec = status(path, result&: st))
1101 return ec;
1102 result = is_directory(status: st);
1103 return std::error_code();
1104}
1105
1106bool is_regular_file(const basic_file_status &status) {
1107 return status.type() == file_type::regular_file;
1108}
1109
1110std::error_code is_regular_file(const Twine &path, bool &result) {
1111 file_status st;
1112 if (std::error_code ec = status(path, result&: st))
1113 return ec;
1114 result = is_regular_file(status: st);
1115 return std::error_code();
1116}
1117
1118bool is_symlink_file(const basic_file_status &status) {
1119 return status.type() == file_type::symlink_file;
1120}
1121
1122std::error_code is_symlink_file(const Twine &path, bool &result) {
1123 file_status st;
1124 if (std::error_code ec = status(path, result&: st, follow: false))
1125 return ec;
1126 result = is_symlink_file(status: st);
1127 return std::error_code();
1128}
1129
1130bool is_other(const basic_file_status &status) {
1131 return exists(status) &&
1132 !is_regular_file(status) &&
1133 !is_directory(status);
1134}
1135
1136std::error_code is_other(const Twine &Path, bool &Result) {
1137 file_status FileStatus;
1138 if (std::error_code EC = status(path: Path, result&: FileStatus))
1139 return EC;
1140 Result = is_other(status: FileStatus);
1141 return std::error_code();
1142}
1143
1144void directory_entry::replace_filename(const Twine &Filename, file_type Type,
1145 basic_file_status Status) {
1146 SmallString<128> PathStr = path::parent_path(path: Path);
1147 path::append(path&: PathStr, a: Filename);
1148 this->Path = std::string(PathStr);
1149 this->Type = Type;
1150 this->Status = Status;
1151}
1152
1153ErrorOr<perms> getPermissions(const Twine &Path) {
1154 file_status Status;
1155 if (std::error_code EC = status(path: Path, result&: Status))
1156 return EC;
1157
1158 return Status.permissions();
1159}
1160
1161size_t mapped_file_region::size() const {
1162 assert(Mapping && "Mapping failed but used anyway!");
1163 return Size;
1164}
1165
1166char *mapped_file_region::data() const {
1167 assert(Mapping && "Mapping failed but used anyway!");
1168 return reinterpret_cast<char *>(Mapping);
1169}
1170
1171const char *mapped_file_region::const_data() const {
1172 assert(Mapping && "Mapping failed but used anyway!");
1173 return reinterpret_cast<const char *>(Mapping);
1174}
1175
1176Error readNativeFileToEOF(file_t FileHandle, SmallVectorImpl<char> &Buffer,
1177 ssize_t ChunkSize) {
1178 // Install a handler to truncate the buffer to the correct size on exit.
1179 size_t Size = Buffer.size();
1180 auto TruncateOnExit = make_scope_exit(F: [&]() { Buffer.truncate(N: Size); });
1181
1182 // Read into Buffer until we hit EOF.
1183 for (;;) {
1184 Buffer.resize_for_overwrite(N: Size + ChunkSize);
1185 Expected<size_t> ReadBytes = readNativeFile(
1186 FileHandle, Buf: MutableArrayRef(Buffer.begin() + Size, ChunkSize));
1187 if (!ReadBytes)
1188 return ReadBytes.takeError();
1189 if (*ReadBytes == 0)
1190 return Error::success();
1191 Size += *ReadBytes;
1192 }
1193}
1194
1195} // end namespace fs
1196} // end namespace sys
1197} // end namespace llvm
1198
1199// Include the truly platform-specific parts.
1200#if defined(LLVM_ON_UNIX)
1201#include "Unix/Path.inc"
1202#endif
1203#if defined(_WIN32)
1204#include "Windows/Path.inc"
1205#endif
1206
1207namespace llvm {
1208namespace sys {
1209namespace fs {
1210
1211TempFile::TempFile(StringRef Name, int FD)
1212 : TmpName(std::string(Name)), FD(FD) {}
1213TempFile::TempFile(TempFile &&Other) { *this = std::move(Other); }
1214TempFile &TempFile::operator=(TempFile &&Other) {
1215 TmpName = std::move(Other.TmpName);
1216 FD = Other.FD;
1217 Other.Done = true;
1218 Other.FD = -1;
1219#ifdef _WIN32
1220 RemoveOnClose = Other.RemoveOnClose;
1221 Other.RemoveOnClose = false;
1222#endif
1223 return *this;
1224}
1225
1226TempFile::~TempFile() { assert(Done); }
1227
1228Error TempFile::discard() {
1229 Done = true;
1230 if (FD != -1 && close(fd: FD) == -1) {
1231 std::error_code EC = std::error_code(errno, std::generic_category());
1232 return errorCodeToError(EC);
1233 }
1234 FD = -1;
1235
1236#ifdef _WIN32
1237 // On Windows, closing will remove the file, if we set the delete
1238 // disposition. If not, remove it manually.
1239 bool Remove = RemoveOnClose;
1240#else
1241 // Always try to remove the file.
1242 bool Remove = true;
1243#endif
1244 std::error_code RemoveEC;
1245 if (Remove && !TmpName.empty()) {
1246 RemoveEC = fs::remove(path: TmpName);
1247 sys::DontRemoveFileOnSignal(Filename: TmpName);
1248 if (!RemoveEC)
1249 TmpName = "";
1250 } else {
1251 TmpName = "";
1252 }
1253 return errorCodeToError(EC: RemoveEC);
1254}
1255
1256Error TempFile::keep(const Twine &Name) {
1257 assert(!Done);
1258 Done = true;
1259 // Always try to close and rename.
1260#ifdef _WIN32
1261 // If we can't cancel the delete don't rename.
1262 auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1263 std::error_code RenameEC =
1264 RemoveOnClose ? std::error_code() : setDeleteDisposition(H, false);
1265 bool ShouldDelete = false;
1266 if (!RenameEC) {
1267 RenameEC = rename_handle(H, Name);
1268 // If rename failed because it's cross-device, copy instead
1269 if (RenameEC ==
1270 std::error_code(ERROR_NOT_SAME_DEVICE, std::system_category())) {
1271 RenameEC = copy_file(TmpName, Name);
1272 ShouldDelete = true;
1273 }
1274 }
1275
1276 // If we can't rename or copy, discard the temporary file.
1277 if (RenameEC)
1278 ShouldDelete = true;
1279 if (ShouldDelete) {
1280 if (!RemoveOnClose)
1281 setDeleteDisposition(H, true);
1282 else
1283 remove(TmpName);
1284 }
1285#else
1286 std::error_code RenameEC = fs::rename(from: TmpName, to: Name);
1287 if (RenameEC) {
1288 // If we can't rename, try to copy to work around cross-device link issues.
1289 RenameEC = sys::fs::copy_file(From: TmpName, To: Name);
1290 // If we can't rename or copy, discard the temporary file.
1291 if (RenameEC)
1292 remove(path: TmpName);
1293 }
1294#endif
1295 sys::DontRemoveFileOnSignal(Filename: TmpName);
1296
1297 if (!RenameEC)
1298 TmpName = "";
1299
1300 if (close(fd: FD) == -1) {
1301 std::error_code EC(errno, std::generic_category());
1302 return errorCodeToError(EC);
1303 }
1304 FD = -1;
1305
1306 return errorCodeToError(EC: RenameEC);
1307}
1308
1309Error TempFile::keep() {
1310 assert(!Done);
1311 Done = true;
1312
1313#ifdef _WIN32
1314 auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1315 if (std::error_code EC = setDeleteDisposition(H, false))
1316 return errorCodeToError(EC);
1317#endif
1318 sys::DontRemoveFileOnSignal(Filename: TmpName);
1319
1320 TmpName = "";
1321
1322 if (close(fd: FD) == -1) {
1323 std::error_code EC(errno, std::generic_category());
1324 return errorCodeToError(EC);
1325 }
1326 FD = -1;
1327
1328 return Error::success();
1329}
1330
1331Expected<TempFile> TempFile::create(const Twine &Model, unsigned Mode,
1332 OpenFlags ExtraFlags) {
1333 int FD;
1334 SmallString<128> ResultPath;
1335 if (std::error_code EC =
1336 createUniqueFile(Model, ResultFd&: FD, ResultPath, Flags: OF_Delete | ExtraFlags, Mode))
1337 return errorCodeToError(EC);
1338
1339 TempFile Ret(ResultPath, FD);
1340#ifdef _WIN32
1341 auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
1342 bool SetSignalHandler = false;
1343 if (std::error_code EC = setDeleteDisposition(H, true)) {
1344 Ret.RemoveOnClose = true;
1345 SetSignalHandler = true;
1346 }
1347#else
1348 bool SetSignalHandler = true;
1349#endif
1350 if (SetSignalHandler && sys::RemoveFileOnSignal(Filename: ResultPath)) {
1351 // Make sure we delete the file when RemoveFileOnSignal fails.
1352 consumeError(Err: Ret.discard());
1353 std::error_code EC(errc::operation_not_permitted);
1354 return errorCodeToError(EC);
1355 }
1356 return std::move(Ret);
1357}
1358} // namespace fs
1359
1360} // namespace sys
1361} // namespace llvm
1362

source code of llvm/lib/Support/Path.cpp