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