1//===- llvm/Support/Unix/Path.inc - Unix Path Implementation ----*- 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 implements the Unix specific implementation of the Path API.
10//
11//===----------------------------------------------------------------------===//
12
13//===----------------------------------------------------------------------===//
14//=== WARNING: Implementation here must contain only generic UNIX code that
15//=== is guaranteed to work on *all* UNIX variants.
16//===----------------------------------------------------------------------===//
17
18#include "Unix.h"
19#include <limits.h>
20#include <stdio.h>
21#if HAVE_SYS_STAT_H
22#include <sys/stat.h>
23#endif
24#if HAVE_FCNTL_H
25#include <fcntl.h>
26#endif
27#ifdef HAVE_UNISTD_H
28#include <unistd.h>
29#endif
30#ifdef HAVE_SYS_MMAN_H
31#include <sys/mman.h>
32#endif
33
34#include <dirent.h>
35#include <pwd.h>
36#include <sys/file.h>
37
38#ifdef __APPLE__
39#include <copyfile.h>
40#include <mach-o/dyld.h>
41#include <sys/attr.h>
42#if __has_include(<sys/clonefile.h>)
43#include <sys/clonefile.h>
44#endif
45#elif defined(__FreeBSD__)
46#include <osreldate.h>
47#if __FreeBSD_version >= 1300057
48#include <sys/auxv.h>
49#else
50#include <machine/elf.h>
51extern char **environ;
52#endif
53#elif defined(__DragonFly__)
54#include <sys/mount.h>
55#elif defined(__MVS__)
56#include "llvm/Support/AutoConvert.h"
57#include <sys/ps.h>
58#endif
59
60// Both stdio.h and cstdio are included via different paths and
61// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
62// either.
63#undef ferror
64#undef feof
65
66#if !defined(PATH_MAX)
67// For GNU Hurd
68#if defined(__GNU__)
69#define PATH_MAX 4096
70#elif defined(__MVS__)
71#define PATH_MAX _XOPEN_PATH_MAX
72#endif
73#endif
74
75#include <sys/types.h>
76#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && \
77 !defined(__linux__) && !defined(__FreeBSD_kernel__) && !defined(_AIX)
78#include <sys/statvfs.h>
79#define STATVFS statvfs
80#define FSTATVFS fstatvfs
81#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
82#else
83#if defined(__OpenBSD__) || defined(__FreeBSD__)
84#include <sys/mount.h>
85#include <sys/param.h>
86#elif defined(__linux__)
87#if defined(HAVE_LINUX_MAGIC_H)
88#include <linux/magic.h>
89#else
90#if defined(HAVE_LINUX_NFS_FS_H)
91#include <linux/nfs_fs.h>
92#endif
93#if defined(HAVE_LINUX_SMB_H)
94#include <linux/smb.h>
95#endif
96#endif
97#include <sys/vfs.h>
98#elif defined(_AIX)
99#include <sys/statfs.h>
100
101// <sys/vmount.h> depends on `uint` to be a typedef from <sys/types.h> to
102// `uint_t`; however, <sys/types.h> does not always declare `uint`. We provide
103// the typedef prior to including <sys/vmount.h> to work around this issue.
104typedef uint_t uint;
105#include <sys/vmount.h>
106#else
107#include <sys/mount.h>
108#endif
109#define STATVFS statfs
110#define FSTATVFS fstatfs
111#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
112#endif
113
114#if defined(__NetBSD__) || defined(__DragonFly__) || defined(__GNU__) || \
115 defined(__MVS__)
116#define STATVFS_F_FLAG(vfs) (vfs).f_flag
117#else
118#define STATVFS_F_FLAG(vfs) (vfs).f_flags
119#endif
120
121using namespace llvm;
122
123namespace llvm {
124namespace sys {
125namespace fs {
126
127const file_t kInvalidFile = -1;
128
129#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || \
130 defined(__FreeBSD_kernel__) || defined(__linux__) || defined(__CYGWIN__) || \
131 defined(__DragonFly__) || defined(_AIX) || defined(__GNU__) || \
132 (defined(__sun__) && defined(__svr4__) || defined(__HAIKU__))
133static int test_dir(char ret[PATH_MAX], const char *dir, const char *bin) {
134 struct stat sb;
135 char fullpath[PATH_MAX];
136
137 int chars = snprintf(s: fullpath, PATH_MAX, format: "%s/%s", dir, bin);
138 // We cannot write PATH_MAX characters because the string will be terminated
139 // with a null character. Fail if truncation happened.
140 if (chars >= PATH_MAX)
141 return 1;
142 if (!realpath(name: fullpath, resolved: ret))
143 return 1;
144 if (stat(file: fullpath, buf: &sb) != 0)
145 return 1;
146
147 return 0;
148}
149
150static char *getprogpath(char ret[PATH_MAX], const char *bin) {
151 if (bin == nullptr)
152 return nullptr;
153
154 /* First approach: absolute path. */
155 if (bin[0] == '/') {
156 if (test_dir(ret, dir: "/", bin) == 0)
157 return ret;
158 return nullptr;
159 }
160
161 /* Second approach: relative path. */
162 if (strchr(s: bin, c: '/')) {
163 char cwd[PATH_MAX];
164 if (!getcwd(buf: cwd, PATH_MAX))
165 return nullptr;
166 if (test_dir(ret, dir: cwd, bin) == 0)
167 return ret;
168 return nullptr;
169 }
170
171 /* Third approach: $PATH */
172 char *pv;
173 if ((pv = getenv(name: "PATH")) == nullptr)
174 return nullptr;
175 char *s = strdup(s: pv);
176 if (!s)
177 return nullptr;
178 char *state;
179 for (char *t = strtok_r(s: s, delim: ":", save_ptr: &state); t != nullptr;
180 t = strtok_r(s: nullptr, delim: ":", save_ptr: &state)) {
181 if (test_dir(ret, dir: t, bin) == 0) {
182 free(ptr: s);
183 return ret;
184 }
185 }
186 free(ptr: s);
187 return nullptr;
188}
189#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
190
191/// GetMainExecutable - Return the path to the main executable, given the
192/// value of argv[0] from program startup.
193std::string getMainExecutable(const char *argv0, void *MainAddr) {
194#if defined(__APPLE__)
195 // On OS X the executable path is saved to the stack by dyld. Reading it
196 // from there is much faster than calling dladdr, especially for large
197 // binaries with symbols.
198 char exe_path[PATH_MAX];
199 uint32_t size = sizeof(exe_path);
200 if (_NSGetExecutablePath(exe_path, &size) == 0) {
201 char link_path[PATH_MAX];
202 if (realpath(exe_path, link_path))
203 return link_path;
204 }
205#elif defined(__FreeBSD__)
206 // On FreeBSD if the exec path specified in ELF auxiliary vectors is
207 // preferred, if available. /proc/curproc/file and the KERN_PROC_PATHNAME
208 // sysctl may not return the desired path if there are multiple hardlinks
209 // to the file.
210 char exe_path[PATH_MAX];
211#if __FreeBSD_version >= 1300057
212 if (elf_aux_info(AT_EXECPATH, exe_path, sizeof(exe_path)) == 0) {
213 char link_path[PATH_MAX];
214 if (realpath(exe_path, link_path))
215 return link_path;
216 }
217#else
218 // elf_aux_info(AT_EXECPATH, ... is not available in all supported versions,
219 // fall back to finding the ELF auxiliary vectors after the process's
220 // environment.
221 char **p = ::environ;
222 while (*p++ != 0)
223 ;
224 // Iterate through auxiliary vectors for AT_EXECPATH.
225 for (Elf_Auxinfo *aux = (Elf_Auxinfo *)p; aux->a_type != AT_NULL; aux++) {
226 if (aux->a_type == AT_EXECPATH) {
227 char link_path[PATH_MAX];
228 if (realpath((char *)aux->a_un.a_ptr, link_path))
229 return link_path;
230 }
231 }
232#endif
233 // Fall back to argv[0] if auxiliary vectors are not available.
234 if (getprogpath(exe_path, argv0) != NULL)
235 return exe_path;
236#elif defined(_AIX) || defined(__DragonFly__) || defined(__FreeBSD_kernel__) || \
237 defined(__NetBSD__)
238 const char *curproc = "/proc/curproc/file";
239 char exe_path[PATH_MAX];
240 if (sys::fs::exists(curproc)) {
241 ssize_t len = readlink(curproc, exe_path, sizeof(exe_path));
242 if (len > 0) {
243 // Null terminate the string for realpath. readlink never null
244 // terminates its output.
245 len = std::min(len, ssize_t(sizeof(exe_path) - 1));
246 exe_path[len] = '\0';
247 return exe_path;
248 }
249 }
250 // If we don't have procfs mounted, fall back to argv[0]
251 if (getprogpath(exe_path, argv0) != NULL)
252 return exe_path;
253#elif defined(__linux__) || defined(__CYGWIN__) || defined(__gnu_hurd__)
254 char exe_path[PATH_MAX];
255 const char *aPath = "/proc/self/exe";
256 if (sys::fs::exists(Path: aPath)) {
257 // /proc is not always mounted under Linux (chroot for example).
258 ssize_t len = readlink(path: aPath, buf: exe_path, len: sizeof(exe_path));
259 if (len < 0)
260 return "";
261
262 // Null terminate the string for realpath. readlink never null
263 // terminates its output.
264 len = std::min(a: len, b: ssize_t(sizeof(exe_path) - 1));
265 exe_path[len] = '\0';
266
267 // On Linux, /proc/self/exe always looks through symlinks. However, on
268 // GNU/Hurd, /proc/self/exe is a symlink to the path that was used to start
269 // the program, and not the eventual binary file. Therefore, call realpath
270 // so this behaves the same on all platforms.
271#if _POSIX_VERSION >= 200112 || defined(__GLIBC__)
272 if (char *real_path = realpath(name: exe_path, resolved: nullptr)) {
273 std::string ret = std::string(real_path);
274 free(ptr: real_path);
275 return ret;
276 }
277#else
278 char real_path[PATH_MAX];
279 if (realpath(exe_path, real_path))
280 return std::string(real_path);
281#endif
282 }
283 // Fall back to the classical detection.
284 if (getprogpath(ret: exe_path, bin: argv0))
285 return exe_path;
286#elif defined(__OpenBSD__) || defined(__HAIKU__)
287 char exe_path[PATH_MAX];
288 // argv[0] only
289 if (getprogpath(exe_path, argv0) != NULL)
290 return exe_path;
291#elif defined(__sun__) && defined(__svr4__)
292 char exe_path[PATH_MAX];
293 const char *aPath = "/proc/self/execname";
294 if (sys::fs::exists(aPath)) {
295 int fd = open(aPath, O_RDONLY);
296 if (fd == -1)
297 return "";
298 if (read(fd, exe_path, sizeof(exe_path)) < 0)
299 return "";
300 return exe_path;
301 }
302 // Fall back to the classical detection.
303 if (getprogpath(exe_path, argv0) != NULL)
304 return exe_path;
305#elif defined(__MVS__)
306 int token = 0;
307 W_PSPROC buf;
308 char exe_path[PS_PATHBLEN];
309 pid_t pid = getpid();
310
311 memset(&buf, 0, sizeof(buf));
312 buf.ps_pathptr = exe_path;
313 buf.ps_pathlen = sizeof(exe_path);
314
315 while (true) {
316 if ((token = w_getpsent(token, &buf, sizeof(buf))) <= 0)
317 break;
318 if (buf.ps_pid != pid)
319 continue;
320 char real_path[PATH_MAX];
321 if (realpath(exe_path, real_path))
322 return std::string(real_path);
323 break; // Found entry, but realpath failed.
324 }
325#elif defined(HAVE_DLFCN_H) && defined(HAVE_DLADDR)
326 // Use dladdr to get executable path if available.
327 Dl_info DLInfo;
328 int err = dladdr(MainAddr, &DLInfo);
329 if (err == 0)
330 return "";
331
332 // If the filename is a symlink, we need to resolve and return the location of
333 // the actual executable.
334 char link_path[PATH_MAX];
335 if (realpath(DLInfo.dli_fname, link_path))
336 return link_path;
337#else
338#error GetMainExecutable is not implemented on this host yet.
339#endif
340 return "";
341}
342
343TimePoint<> basic_file_status::getLastAccessedTime() const {
344 return toTimePoint(T: fs_st_atime, nsec: fs_st_atime_nsec);
345}
346
347TimePoint<> basic_file_status::getLastModificationTime() const {
348 return toTimePoint(T: fs_st_mtime, nsec: fs_st_mtime_nsec);
349}
350
351UniqueID file_status::getUniqueID() const {
352 return UniqueID(fs_st_dev, fs_st_ino);
353}
354
355uint32_t file_status::getLinkCount() const { return fs_st_nlinks; }
356
357ErrorOr<space_info> disk_space(const Twine &Path) {
358 struct STATVFS Vfs;
359 if (::STATVFS(file: const_cast<char *>(Path.str().c_str()), buf: &Vfs))
360 return errnoAsErrorCode();
361 auto FrSize = STATVFS_F_FRSIZE(Vfs);
362 space_info SpaceInfo;
363 SpaceInfo.capacity = static_cast<uint64_t>(Vfs.f_blocks) * FrSize;
364 SpaceInfo.free = static_cast<uint64_t>(Vfs.f_bfree) * FrSize;
365 SpaceInfo.available = static_cast<uint64_t>(Vfs.f_bavail) * FrSize;
366 return SpaceInfo;
367}
368
369std::error_code current_path(SmallVectorImpl<char> &result) {
370 result.clear();
371
372 const char *pwd = ::getenv(name: "PWD");
373 llvm::sys::fs::file_status PWDStatus, DotStatus;
374 if (pwd && llvm::sys::path::is_absolute(path: pwd) &&
375 !llvm::sys::fs::status(path: pwd, result&: PWDStatus) &&
376 !llvm::sys::fs::status(path: ".", result&: DotStatus) &&
377 PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
378 result.append(in_start: pwd, in_end: pwd + strlen(s: pwd));
379 return std::error_code();
380 }
381
382 result.resize_for_overwrite(PATH_MAX);
383
384 while (true) {
385 if (::getcwd(buf: result.data(), size: result.size()) == nullptr) {
386 // See if there was a real error.
387 if (errno != ENOMEM) {
388 result.clear();
389 return errnoAsErrorCode();
390 }
391 // Otherwise there just wasn't enough space.
392 result.resize_for_overwrite(N: result.capacity() * 2);
393 } else
394 break;
395 }
396
397 result.truncate(N: strlen(s: result.data()));
398 return std::error_code();
399}
400
401std::error_code set_current_path(const Twine &path) {
402 SmallString<128> path_storage;
403 StringRef p = path.toNullTerminatedStringRef(Out&: path_storage);
404
405 if (::chdir(path: p.begin()) == -1)
406 return errnoAsErrorCode();
407
408 return std::error_code();
409}
410
411std::error_code create_directory(const Twine &path, bool IgnoreExisting,
412 perms Perms) {
413 SmallString<128> path_storage;
414 StringRef p = path.toNullTerminatedStringRef(Out&: path_storage);
415
416 if (::mkdir(path: p.begin(), mode: Perms) == -1) {
417 if (errno != EEXIST || !IgnoreExisting)
418 return errnoAsErrorCode();
419 }
420
421 return std::error_code();
422}
423
424// Note that we are using symbolic link because hard links are not supported by
425// all filesystems (SMB doesn't).
426std::error_code create_link(const Twine &to, const Twine &from) {
427 // Get arguments.
428 SmallString<128> from_storage;
429 SmallString<128> to_storage;
430 StringRef f = from.toNullTerminatedStringRef(Out&: from_storage);
431 StringRef t = to.toNullTerminatedStringRef(Out&: to_storage);
432
433 if (::symlink(from: t.begin(), to: f.begin()) == -1)
434 return errnoAsErrorCode();
435
436 return std::error_code();
437}
438
439std::error_code create_hard_link(const Twine &to, const Twine &from) {
440 // Get arguments.
441 SmallString<128> from_storage;
442 SmallString<128> to_storage;
443 StringRef f = from.toNullTerminatedStringRef(Out&: from_storage);
444 StringRef t = to.toNullTerminatedStringRef(Out&: to_storage);
445
446 if (::link(from: t.begin(), to: f.begin()) == -1)
447 return errnoAsErrorCode();
448
449 return std::error_code();
450}
451
452std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
453 SmallString<128> path_storage;
454 StringRef p = path.toNullTerminatedStringRef(Out&: path_storage);
455
456 struct stat buf;
457 if (lstat(file: p.begin(), buf: &buf) != 0) {
458 if (errno != ENOENT || !IgnoreNonExisting)
459 return errnoAsErrorCode();
460 return std::error_code();
461 }
462
463 // Note: this check catches strange situations. In all cases, LLVM should
464 // only be involved in the creation and deletion of regular files. This
465 // check ensures that what we're trying to erase is a regular file. It
466 // effectively prevents LLVM from erasing things like /dev/null, any block
467 // special file, or other things that aren't "regular" files.
468 if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
469 return make_error_code(E: errc::operation_not_permitted);
470
471 if (::remove(filename: p.begin()) == -1) {
472 if (errno != ENOENT || !IgnoreNonExisting)
473 return errnoAsErrorCode();
474 }
475
476 return std::error_code();
477}
478
479static bool is_local_impl(struct STATVFS &Vfs) {
480#if defined(__linux__) || defined(__GNU__)
481#ifndef NFS_SUPER_MAGIC
482#define NFS_SUPER_MAGIC 0x6969
483#endif
484#ifndef SMB_SUPER_MAGIC
485#define SMB_SUPER_MAGIC 0x517B
486#endif
487#ifndef CIFS_MAGIC_NUMBER
488#define CIFS_MAGIC_NUMBER 0xFF534D42
489#endif
490#ifdef __GNU__
491 switch ((uint32_t)Vfs.__f_type) {
492#else
493 switch ((uint32_t)Vfs.f_type) {
494#endif
495 case NFS_SUPER_MAGIC:
496 case SMB_SUPER_MAGIC:
497 case CIFS_MAGIC_NUMBER:
498 return false;
499 default:
500 return true;
501 }
502#elif defined(__CYGWIN__)
503 // Cygwin doesn't expose this information; would need to use Win32 API.
504 return false;
505#elif defined(__Fuchsia__)
506 // Fuchsia doesn't yet support remote filesystem mounts.
507 return true;
508#elif defined(__EMSCRIPTEN__)
509 // Emscripten doesn't currently support remote filesystem mounts.
510 return true;
511#elif defined(__HAIKU__)
512 // Haiku doesn't expose this information.
513 return false;
514#elif defined(__sun)
515 // statvfs::f_basetype contains a null-terminated FSType name of the mounted
516 // target
517 StringRef fstype(Vfs.f_basetype);
518 // NFS is the only non-local fstype??
519 return fstype != "nfs";
520#elif defined(_AIX)
521 // Call mntctl; try more than twice in case of timing issues with a concurrent
522 // mount.
523 int Ret;
524 size_t BufSize = 2048u;
525 std::unique_ptr<char[]> Buf;
526 int Tries = 3;
527 while (Tries--) {
528 Buf = std::make_unique<char[]>(BufSize);
529 Ret = mntctl(MCTL_QUERY, BufSize, Buf.get());
530 if (Ret != 0)
531 break;
532 BufSize = *reinterpret_cast<unsigned int *>(Buf.get());
533 Buf.reset();
534 }
535
536 if (Ret == -1)
537 // There was an error; "remote" is the conservative answer.
538 return false;
539
540 // Look for the correct vmount entry.
541 char *CurObjPtr = Buf.get();
542 while (Ret--) {
543 struct vmount *Vp = reinterpret_cast<struct vmount *>(CurObjPtr);
544 static_assert(sizeof(Vfs.f_fsid) == sizeof(Vp->vmt_fsid),
545 "fsid length mismatch");
546 if (memcmp(&Vfs.f_fsid, &Vp->vmt_fsid, sizeof Vfs.f_fsid) == 0)
547 return (Vp->vmt_flags & MNT_REMOTE) == 0;
548
549 CurObjPtr += Vp->vmt_length;
550 }
551
552 // vmount entry not found; "remote" is the conservative answer.
553 return false;
554#elif defined(__MVS__)
555 // The file system can have an arbitrary structure on z/OS; must go with the
556 // conservative answer.
557 return false;
558#else
559 return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
560#endif
561}
562
563std::error_code is_local(const Twine &Path, bool &Result) {
564 struct STATVFS Vfs;
565 if (::STATVFS(file: const_cast<char *>(Path.str().c_str()), buf: &Vfs))
566 return errnoAsErrorCode();
567
568 Result = is_local_impl(Vfs);
569 return std::error_code();
570}
571
572std::error_code is_local(int FD, bool &Result) {
573 struct STATVFS Vfs;
574 if (::FSTATVFS(fildes: FD, buf: &Vfs))
575 return errnoAsErrorCode();
576
577 Result = is_local_impl(Vfs);
578 return std::error_code();
579}
580
581std::error_code rename(const Twine &from, const Twine &to) {
582 // Get arguments.
583 SmallString<128> from_storage;
584 SmallString<128> to_storage;
585 StringRef f = from.toNullTerminatedStringRef(Out&: from_storage);
586 StringRef t = to.toNullTerminatedStringRef(Out&: to_storage);
587
588 if (::rename(old: f.begin(), new: t.begin()) == -1)
589 return errnoAsErrorCode();
590
591 return std::error_code();
592}
593
594std::error_code resize_file(int FD, uint64_t Size) {
595 // Use ftruncate as a fallback. It may or may not allocate space. At least on
596 // OS X with HFS+ it does.
597 if (::ftruncate(fd: FD, length: Size) == -1)
598 return errnoAsErrorCode();
599
600 return std::error_code();
601}
602
603static int convertAccessMode(AccessMode Mode) {
604 switch (Mode) {
605 case AccessMode::Exist:
606 return F_OK;
607 case AccessMode::Write:
608 return W_OK;
609 case AccessMode::Execute:
610 return R_OK | X_OK; // scripts also need R_OK.
611 }
612 llvm_unreachable("invalid enum");
613}
614
615std::error_code access(const Twine &Path, AccessMode Mode) {
616 SmallString<128> PathStorage;
617 StringRef P = Path.toNullTerminatedStringRef(Out&: PathStorage);
618
619 if (::access(name: P.begin(), type: convertAccessMode(Mode)) == -1)
620 return errnoAsErrorCode();
621
622 if (Mode == AccessMode::Execute) {
623 // Don't say that directories are executable.
624 struct stat buf;
625 if (0 != stat(file: P.begin(), buf: &buf))
626 return errc::permission_denied;
627 if (!S_ISREG(buf.st_mode))
628 return errc::permission_denied;
629 }
630
631 return std::error_code();
632}
633
634bool can_execute(const Twine &Path) {
635 return !access(Path, Mode: AccessMode::Execute);
636}
637
638bool equivalent(file_status A, file_status B) {
639 assert(status_known(A) && status_known(B));
640 return A.fs_st_dev == B.fs_st_dev && A.fs_st_ino == B.fs_st_ino;
641}
642
643std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
644 file_status fsA, fsB;
645 if (std::error_code ec = status(path: A, result&: fsA))
646 return ec;
647 if (std::error_code ec = status(path: B, result&: fsB))
648 return ec;
649 result = equivalent(A: fsA, B: fsB);
650 return std::error_code();
651}
652
653static void expandTildeExpr(SmallVectorImpl<char> &Path) {
654 StringRef PathStr(Path.begin(), Path.size());
655 if (PathStr.empty() || !PathStr.starts_with(Prefix: "~"))
656 return;
657
658 PathStr = PathStr.drop_front();
659 StringRef Expr =
660 PathStr.take_until(F: [](char c) { return path::is_separator(value: c); });
661 StringRef Remainder = PathStr.substr(Start: Expr.size() + 1);
662 SmallString<128> Storage;
663 if (Expr.empty()) {
664 // This is just ~/..., resolve it to the current user's home dir.
665 if (!path::home_directory(result&: Storage)) {
666 // For some reason we couldn't get the home directory. Just exit.
667 return;
668 }
669
670 // Overwrite the first character and insert the rest.
671 Path[0] = Storage[0];
672 Path.insert(I: Path.begin() + 1, From: Storage.begin() + 1, To: Storage.end());
673 return;
674 }
675
676 // This is a string of the form ~username/, look up this user's entry in the
677 // password database.
678 std::unique_ptr<char[]> Buf;
679 long BufSize = sysconf(_SC_GETPW_R_SIZE_MAX);
680 if (BufSize <= 0)
681 BufSize = 16384;
682 Buf = std::make_unique<char[]>(num: BufSize);
683 struct passwd Pwd;
684 std::string User = Expr.str();
685 struct passwd *Entry = nullptr;
686 getpwnam_r(name: User.c_str(), resultbuf: &Pwd, buffer: Buf.get(), buflen: BufSize, result: &Entry);
687
688 if (!Entry || !Entry->pw_dir) {
689 // Unable to look up the entry, just return back the original path.
690 return;
691 }
692
693 Storage = Remainder;
694 Path.clear();
695 Path.append(in_start: Entry->pw_dir, in_end: Entry->pw_dir + strlen(s: Entry->pw_dir));
696 llvm::sys::path::append(path&: Path, a: Storage);
697}
698
699void expand_tilde(const Twine &path, SmallVectorImpl<char> &dest) {
700 dest.clear();
701 if (path.isTriviallyEmpty())
702 return;
703
704 path.toVector(Out&: dest);
705 expandTildeExpr(Path&: dest);
706}
707
708static file_type typeForMode(mode_t Mode) {
709 if (S_ISDIR(Mode))
710 return file_type::directory_file;
711 else if (S_ISREG(Mode))
712 return file_type::regular_file;
713 else if (S_ISBLK(Mode))
714 return file_type::block_file;
715 else if (S_ISCHR(Mode))
716 return file_type::character_file;
717 else if (S_ISFIFO(Mode))
718 return file_type::fifo_file;
719 else if (S_ISSOCK(Mode))
720 return file_type::socket_file;
721 else if (S_ISLNK(Mode))
722 return file_type::symlink_file;
723 return file_type::type_unknown;
724}
725
726static std::error_code fillStatus(int StatRet, const struct stat &Status,
727 file_status &Result) {
728 if (StatRet != 0) {
729 std::error_code EC = errnoAsErrorCode();
730 if (EC == errc::no_such_file_or_directory)
731 Result = file_status(file_type::file_not_found);
732 else
733 Result = file_status(file_type::status_error);
734 return EC;
735 }
736
737 uint32_t atime_nsec, mtime_nsec;
738#if defined(HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC)
739 atime_nsec = Status.st_atimespec.tv_nsec;
740 mtime_nsec = Status.st_mtimespec.tv_nsec;
741#elif defined(HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC)
742 atime_nsec = Status.st_atim.tv_nsec;
743 mtime_nsec = Status.st_mtim.tv_nsec;
744#else
745 atime_nsec = mtime_nsec = 0;
746#endif
747
748 perms Perms = static_cast<perms>(Status.st_mode) & all_perms;
749 Result = file_status(typeForMode(Mode: Status.st_mode), Perms, Status.st_dev,
750 Status.st_nlink, Status.st_ino, Status.st_atime,
751 atime_nsec, Status.st_mtime, mtime_nsec, Status.st_uid,
752 Status.st_gid, Status.st_size);
753
754 return std::error_code();
755}
756
757std::error_code status(const Twine &Path, file_status &Result, bool Follow) {
758 SmallString<128> PathStorage;
759 StringRef P = Path.toNullTerminatedStringRef(Out&: PathStorage);
760
761 struct stat Status;
762 int StatRet = (Follow ? ::stat : ::lstat)(P.begin(), &Status);
763 return fillStatus(StatRet, Status, Result);
764}
765
766std::error_code status(int FD, file_status &Result) {
767 struct stat Status;
768 int StatRet = ::fstat(fd: FD, buf: &Status);
769 return fillStatus(StatRet, Status, Result);
770}
771
772unsigned getUmask() {
773 // Chose arbitary new mask and reset the umask to the old mask.
774 // umask(2) never fails so ignore the return of the second call.
775 unsigned Mask = ::umask(mask: 0);
776 (void)::umask(mask: Mask);
777 return Mask;
778}
779
780std::error_code setPermissions(const Twine &Path, perms Permissions) {
781 SmallString<128> PathStorage;
782 StringRef P = Path.toNullTerminatedStringRef(Out&: PathStorage);
783
784 if (::chmod(file: P.begin(), mode: Permissions))
785 return errnoAsErrorCode();
786 return std::error_code();
787}
788
789std::error_code setPermissions(int FD, perms Permissions) {
790 if (::fchmod(fd: FD, mode: Permissions))
791 return errnoAsErrorCode();
792 return std::error_code();
793}
794
795std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
796 TimePoint<> ModificationTime) {
797#if defined(HAVE_FUTIMENS)
798 timespec Times[2];
799 Times[0] = sys::toTimeSpec(TP: AccessTime);
800 Times[1] = sys::toTimeSpec(TP: ModificationTime);
801 if (::futimens(fd: FD, times: Times))
802 return errnoAsErrorCode();
803 return std::error_code();
804#elif defined(HAVE_FUTIMES)
805 timeval Times[2];
806 Times[0] = sys::toTimeVal(
807 std::chrono::time_point_cast<std::chrono::microseconds>(AccessTime));
808 Times[1] =
809 sys::toTimeVal(std::chrono::time_point_cast<std::chrono::microseconds>(
810 ModificationTime));
811 if (::futimes(FD, Times))
812 return errnoAsErrorCode();
813 return std::error_code();
814#elif defined(__MVS__)
815 attrib_t Attr;
816 memset(&Attr, 0, sizeof(Attr));
817 Attr.att_atimechg = 1;
818 Attr.att_atime = sys::toTimeT(AccessTime);
819 Attr.att_mtimechg = 1;
820 Attr.att_mtime = sys::toTimeT(ModificationTime);
821 if (::__fchattr(FD, &Attr, sizeof(Attr)) != 0)
822 return errnoAsErrorCode();
823 return std::error_code();
824#else
825#warning Missing futimes() and futimens()
826 return make_error_code(errc::function_not_supported);
827#endif
828}
829
830std::error_code mapped_file_region::init(int FD, uint64_t Offset,
831 mapmode Mode) {
832 assert(Size != 0);
833
834 int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
835 int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
836#if defined(MAP_NORESERVE)
837 flags |= MAP_NORESERVE;
838#endif
839#if defined(__APPLE__)
840 //----------------------------------------------------------------------
841 // Newer versions of MacOSX have a flag that will allow us to read from
842 // binaries whose code signature is invalid without crashing by using
843 // the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media
844 // is mapped we can avoid crashing and return zeroes to any pages we try
845 // to read if the media becomes unavailable by using the
846 // MAP_RESILIENT_MEDIA flag. These flags are only usable when mapping
847 // with PROT_READ, so take care not to specify them otherwise.
848 //----------------------------------------------------------------------
849 if (Mode == readonly) {
850#if defined(MAP_RESILIENT_CODESIGN)
851 flags |= MAP_RESILIENT_CODESIGN;
852#endif
853#if defined(MAP_RESILIENT_MEDIA)
854 flags |= MAP_RESILIENT_MEDIA;
855#endif
856 }
857#endif // #if defined (__APPLE__)
858
859 Mapping = ::mmap(addr: nullptr, len: Size, prot: prot, flags: flags, fd: FD, offset: Offset);
860 if (Mapping == MAP_FAILED)
861 return errnoAsErrorCode();
862 return std::error_code();
863}
864
865mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
866 uint64_t offset, std::error_code &ec)
867 : Size(length), Mode(mode) {
868 (void)Mode;
869 ec = init(FD: fd, Offset: offset, Mode: mode);
870 if (ec)
871 copyFrom(Copied: mapped_file_region());
872}
873
874void mapped_file_region::unmapImpl() {
875 if (Mapping)
876 ::munmap(addr: Mapping, len: Size);
877}
878
879void mapped_file_region::dontNeedImpl() {
880 assert(Mode == mapped_file_region::readonly);
881 if (!Mapping)
882 return;
883#if defined(__MVS__) || defined(_AIX)
884 // If we don't have madvise, or it isn't beneficial, treat this as a no-op.
885#elif defined(POSIX_MADV_DONTNEED)
886 ::posix_madvise(addr: Mapping, len: Size, POSIX_MADV_DONTNEED);
887#else
888 ::madvise(Mapping, Size, MADV_DONTNEED);
889#endif
890}
891
892int mapped_file_region::alignment() { return Process::getPageSizeEstimate(); }
893
894std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
895 StringRef path,
896 bool follow_symlinks) {
897 SmallString<128> path_null(path);
898 DIR *directory = ::opendir(name: path_null.c_str());
899 if (!directory)
900 return errnoAsErrorCode();
901
902 it.IterationHandle = reinterpret_cast<intptr_t>(directory);
903 // Add something for replace_filename to replace.
904 path::append(path&: path_null, a: ".");
905 it.CurrentEntry = directory_entry(path_null.str(), follow_symlinks);
906 return directory_iterator_increment(it);
907}
908
909std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
910 if (it.IterationHandle)
911 ::closedir(dirp: reinterpret_cast<DIR *>(it.IterationHandle));
912 it.IterationHandle = 0;
913 it.CurrentEntry = directory_entry();
914 return std::error_code();
915}
916
917static file_type direntType(dirent *Entry) {
918 // Most platforms provide the file type in the dirent: Linux/BSD/Mac.
919 // The DTTOIF macro lets us reuse our status -> type conversion.
920 // Note that while glibc provides a macro to see if this is supported,
921 // _DIRENT_HAVE_D_TYPE, it's not defined on BSD/Mac, so we test for the
922 // d_type-to-mode_t conversion macro instead.
923#if defined(DTTOIF)
924 return typeForMode(DTTOIF(Entry->d_type));
925#else
926 // Other platforms such as Solaris require a stat() to get the type.
927 return file_type::type_unknown;
928#endif
929}
930
931std::error_code detail::directory_iterator_increment(detail::DirIterState &It) {
932 errno = 0;
933 dirent *CurDir = ::readdir(dirp: reinterpret_cast<DIR *>(It.IterationHandle));
934 if (CurDir == nullptr && errno != 0) {
935 return errnoAsErrorCode();
936 } else if (CurDir != nullptr) {
937 StringRef Name(CurDir->d_name);
938 if ((Name.size() == 1 && Name[0] == '.') ||
939 (Name.size() == 2 && Name[0] == '.' && Name[1] == '.'))
940 return directory_iterator_increment(It);
941 It.CurrentEntry.replace_filename(Filename: Name, Type: direntType(Entry: CurDir));
942 } else
943 return directory_iterator_destruct(it&: It);
944
945 return std::error_code();
946}
947
948ErrorOr<basic_file_status> directory_entry::status() const {
949 file_status s;
950 if (auto EC = fs::status(Path, Result&: s, Follow: FollowSymlinks))
951 return EC;
952 return s;
953}
954
955//
956// FreeBSD optionally provides /proc/self/fd, but it is incompatible with
957// Linux. The thing to use is realpath.
958//
959#if !defined(__FreeBSD__) && !defined(__OpenBSD__)
960#define TRY_PROC_SELF_FD
961#endif
962
963#if !defined(F_GETPATH) && defined(TRY_PROC_SELF_FD)
964static bool hasProcSelfFD() {
965 // If we have a /proc filesystem mounted, we can quickly establish the
966 // real name of the file with readlink
967 static const bool Result = (::access(name: "/proc/self/fd", R_OK) == 0);
968 return Result;
969}
970#endif
971
972static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
973 FileAccess Access) {
974 int Result = 0;
975 if (Access == FA_Read)
976 Result |= O_RDONLY;
977 else if (Access == FA_Write)
978 Result |= O_WRONLY;
979 else if (Access == (FA_Read | FA_Write))
980 Result |= O_RDWR;
981
982 // This is for compatibility with old code that assumed OF_Append implied
983 // would open an existing file. See Windows/Path.inc for a longer comment.
984 if (Flags & OF_Append)
985 Disp = CD_OpenAlways;
986
987 if (Disp == CD_CreateNew) {
988 Result |= O_CREAT; // Create if it doesn't exist.
989 Result |= O_EXCL; // Fail if it does.
990 } else if (Disp == CD_CreateAlways) {
991 Result |= O_CREAT; // Create if it doesn't exist.
992 Result |= O_TRUNC; // Truncate if it does.
993 } else if (Disp == CD_OpenAlways) {
994 Result |= O_CREAT; // Create if it doesn't exist.
995 } else if (Disp == CD_OpenExisting) {
996 // Nothing special, just don't add O_CREAT and we get these semantics.
997 }
998
999// Using append mode with z/OS UTF-8 auto-conversion results in EINVAL when
1000// calling write(). Instead we need to use lseek() to set offset to EOF after
1001// open().
1002#ifndef __MVS__
1003 if (Flags & OF_Append)
1004 Result |= O_APPEND;
1005#endif
1006
1007#ifdef O_CLOEXEC
1008 if (!(Flags & OF_ChildInherit))
1009 Result |= O_CLOEXEC;
1010#endif
1011
1012 return Result;
1013}
1014
1015std::error_code openFile(const Twine &Name, int &ResultFD,
1016 CreationDisposition Disp, FileAccess Access,
1017 OpenFlags Flags, unsigned Mode) {
1018 int OpenFlags = nativeOpenFlags(Disp, Flags, Access);
1019
1020 SmallString<128> Storage;
1021 StringRef P = Name.toNullTerminatedStringRef(Out&: Storage);
1022 // Call ::open in a lambda to avoid overload resolution in RetryAfterSignal
1023 // when open is overloaded, such as in Bionic.
1024 auto Open = [&]() { return ::open(file: P.begin(), oflag: OpenFlags, Mode); };
1025 if ((ResultFD = sys::RetryAfterSignal(Fail: -1, F: Open)) < 0)
1026 return errnoAsErrorCode();
1027#ifndef O_CLOEXEC
1028 if (!(Flags & OF_ChildInherit)) {
1029 int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC);
1030 (void)r;
1031 assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed");
1032 }
1033#endif
1034
1035#ifdef __MVS__
1036 /* Reason about auto-conversion and file tags. Setting the file tag only
1037 * applies if file is opened in write mode:
1038 *
1039 * Text file:
1040 * File exists File created
1041 * CD_CreateNew n/a conv: on
1042 * tag: set 1047
1043 * CD_CreateAlways conv: auto conv: on
1044 * tag: auto 1047 tag: set 1047
1045 * CD_OpenAlways conv: auto conv: on
1046 * tag: auto 1047 tag: set 1047
1047 * CD_OpenExisting conv: auto n/a
1048 * tag: unchanged
1049 *
1050 * Binary file:
1051 * File exists File created
1052 * CD_CreateNew n/a conv: off
1053 * tag: set binary
1054 * CD_CreateAlways conv: off conv: off
1055 * tag: auto binary tag: set binary
1056 * CD_OpenAlways conv: off conv: off
1057 * tag: auto binary tag: set binary
1058 * CD_OpenExisting conv: off n/a
1059 * tag: unchanged
1060 *
1061 * Actions:
1062 * conv: off -> auto-conversion is turned off
1063 * conv: on -> auto-conversion is turned on
1064 * conv: auto -> auto-conversion is turned on if the file is untagged
1065 * tag: set 1047 -> set the file tag to text encoded in 1047
1066 * tag: set binary -> set the file tag to binary
1067 * tag: auto 1047 -> set file tag to 1047 if not set
1068 * tag: auto binary -> set file tag to binary if not set
1069 * tag: unchanged -> do not care about the file tag
1070 *
1071 * It is not possible to distinguish between the cases "file exists" and
1072 * "file created". In the latter case, the file tag is not set and the file
1073 * size is zero. The decision table boils down to:
1074 *
1075 * the file tag is set if
1076 * - the file is opened for writing
1077 * - the create disposition is not equal to CD_OpenExisting
1078 * - the file tag is not set
1079 * - the file size is zero
1080 *
1081 * This only applies if the file is a regular file. E.g. enabling
1082 * auto-conversion for reading from /dev/null results in error EINVAL when
1083 * calling read().
1084 *
1085 * Using append mode with z/OS UTF-8 auto-conversion results in EINVAL when
1086 * calling write(). Instead we need to use lseek() to set offset to EOF after
1087 * open().
1088 */
1089 if ((Flags & OF_Append) && lseek(ResultFD, 0, SEEK_END) == -1)
1090 return errnoAsErrorCode();
1091 struct stat Stat;
1092 if (fstat(ResultFD, &Stat) == -1)
1093 return errnoAsErrorCode();
1094 if (S_ISREG(Stat.st_mode)) {
1095 bool DoSetTag = (Access & FA_Write) && (Disp != CD_OpenExisting) &&
1096 !Stat.st_tag.ft_txtflag && !Stat.st_tag.ft_ccsid &&
1097 Stat.st_size == 0;
1098 if (Flags & OF_Text) {
1099 if (auto EC = llvm::enableAutoConversion(ResultFD))
1100 return EC;
1101 if (DoSetTag) {
1102 if (auto EC = llvm::setFileTag(ResultFD, CCSID_IBM_1047, true))
1103 return EC;
1104 }
1105 } else {
1106 if (auto EC = llvm::disableAutoConversion(ResultFD))
1107 return EC;
1108 if (DoSetTag) {
1109 if (auto EC = llvm::setFileTag(ResultFD, FT_BINARY, false))
1110 return EC;
1111 }
1112 }
1113 }
1114#endif
1115
1116 return std::error_code();
1117}
1118
1119Expected<int> openNativeFile(const Twine &Name, CreationDisposition Disp,
1120 FileAccess Access, OpenFlags Flags,
1121 unsigned Mode) {
1122
1123 int FD;
1124 std::error_code EC = openFile(Name, ResultFD&: FD, Disp, Access, Flags, Mode);
1125 if (EC)
1126 return errorCodeToError(EC);
1127 return FD;
1128}
1129
1130std::error_code openFileForRead(const Twine &Name, int &ResultFD,
1131 OpenFlags Flags,
1132 SmallVectorImpl<char> *RealPath) {
1133 std::error_code EC =
1134 openFile(Name, ResultFD, Disp: CD_OpenExisting, Access: FA_Read, Flags, Mode: 0666);
1135 if (EC)
1136 return EC;
1137
1138 // Attempt to get the real name of the file, if the user asked
1139 if (!RealPath)
1140 return std::error_code();
1141 RealPath->clear();
1142#if defined(F_GETPATH)
1143 // When F_GETPATH is availble, it is the quickest way to get
1144 // the real path name.
1145 char Buffer[PATH_MAX];
1146 if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
1147 RealPath->append(Buffer, Buffer + strlen(Buffer));
1148#else
1149 char Buffer[PATH_MAX];
1150#if defined(TRY_PROC_SELF_FD)
1151 if (hasProcSelfFD()) {
1152 char ProcPath[64];
1153 snprintf(s: ProcPath, maxlen: sizeof(ProcPath), format: "/proc/self/fd/%d", ResultFD);
1154 ssize_t CharCount = ::readlink(path: ProcPath, buf: Buffer, len: sizeof(Buffer));
1155 if (CharCount > 0)
1156 RealPath->append(in_start: Buffer, in_end: Buffer + CharCount);
1157 } else {
1158#endif
1159 SmallString<128> Storage;
1160 StringRef P = Name.toNullTerminatedStringRef(Out&: Storage);
1161
1162 // Use ::realpath to get the real path name
1163 if (::realpath(name: P.begin(), resolved: Buffer) != nullptr)
1164 RealPath->append(in_start: Buffer, in_end: Buffer + strlen(s: Buffer));
1165#if defined(TRY_PROC_SELF_FD)
1166 }
1167#endif
1168#endif
1169 return std::error_code();
1170}
1171
1172Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
1173 SmallVectorImpl<char> *RealPath) {
1174 file_t ResultFD;
1175 std::error_code EC = openFileForRead(Name, ResultFD, Flags, RealPath);
1176 if (EC)
1177 return errorCodeToError(EC);
1178 return ResultFD;
1179}
1180
1181file_t getStdinHandle() { return 0; }
1182file_t getStdoutHandle() { return 1; }
1183file_t getStderrHandle() { return 2; }
1184
1185Expected<size_t> readNativeFile(file_t FD, MutableArrayRef<char> Buf) {
1186#if defined(__APPLE__)
1187 size_t Size = std::min<size_t>(Buf.size(), INT32_MAX);
1188#else
1189 size_t Size = Buf.size();
1190#endif
1191 ssize_t NumRead = sys::RetryAfterSignal(Fail: -1, F&: ::read, As: FD, As: Buf.data(), As: Size);
1192 if (ssize_t(NumRead) == -1)
1193 return errorCodeToError(EC: errnoAsErrorCode());
1194// The underlying operation on these platforms allow opening directories
1195// for reading in more cases than other platforms.
1196#if defined(__MVS__) || defined(_AIX)
1197 struct stat Status;
1198 if (fstat(FD, &Status) == -1)
1199 return errorCodeToError(errnoAsErrorCode());
1200 if (S_ISDIR(Status.st_mode))
1201 return errorCodeToError(make_error_code(errc::is_a_directory));
1202#endif
1203 return NumRead;
1204}
1205
1206Expected<size_t> readNativeFileSlice(file_t FD, MutableArrayRef<char> Buf,
1207 uint64_t Offset) {
1208#if defined(__APPLE__)
1209 size_t Size = std::min<size_t>(Buf.size(), INT32_MAX);
1210#else
1211 size_t Size = Buf.size();
1212#endif
1213#ifdef HAVE_PREAD
1214 ssize_t NumRead =
1215 sys::RetryAfterSignal(Fail: -1, F&: ::pread, As: FD, As: Buf.data(), As: Size, As: Offset);
1216#else
1217 if (lseek(FD, Offset, SEEK_SET) == -1)
1218 return errorCodeToError(errnoAsErrorCode());
1219 ssize_t NumRead = sys::RetryAfterSignal(-1, ::read, FD, Buf.data(), Size);
1220#endif
1221 if (NumRead == -1)
1222 return errorCodeToError(EC: errnoAsErrorCode());
1223 return NumRead;
1224}
1225
1226std::error_code tryLockFile(int FD, std::chrono::milliseconds Timeout) {
1227 auto Start = std::chrono::steady_clock::now();
1228 auto End = Start + Timeout;
1229 do {
1230 struct flock Lock;
1231 memset(s: &Lock, c: 0, n: sizeof(Lock));
1232 Lock.l_type = F_WRLCK;
1233 Lock.l_whence = SEEK_SET;
1234 Lock.l_start = 0;
1235 Lock.l_len = 0;
1236 if (::fcntl(fd: FD, F_SETLK, &Lock) != -1)
1237 return std::error_code();
1238 int Error = errno;
1239 if (Error != EACCES && Error != EAGAIN)
1240 return std::error_code(Error, std::generic_category());
1241 usleep(useconds: 1000);
1242 } while (std::chrono::steady_clock::now() < End);
1243 return make_error_code(E: errc::no_lock_available);
1244}
1245
1246std::error_code lockFile(int FD) {
1247 struct flock Lock;
1248 memset(s: &Lock, c: 0, n: sizeof(Lock));
1249 Lock.l_type = F_WRLCK;
1250 Lock.l_whence = SEEK_SET;
1251 Lock.l_start = 0;
1252 Lock.l_len = 0;
1253 if (::fcntl(fd: FD, F_SETLKW, &Lock) != -1)
1254 return std::error_code();
1255 return errnoAsErrorCode();
1256}
1257
1258std::error_code unlockFile(int FD) {
1259 struct flock Lock;
1260 Lock.l_type = F_UNLCK;
1261 Lock.l_whence = SEEK_SET;
1262 Lock.l_start = 0;
1263 Lock.l_len = 0;
1264 if (::fcntl(fd: FD, F_SETLK, &Lock) != -1)
1265 return std::error_code();
1266 return errnoAsErrorCode();
1267}
1268
1269std::error_code closeFile(file_t &F) {
1270 file_t TmpF = F;
1271 F = kInvalidFile;
1272 return Process::SafelyCloseFileDescriptor(FD: TmpF);
1273}
1274
1275template <typename T>
1276static std::error_code remove_directories_impl(const T &Entry,
1277 bool IgnoreErrors) {
1278 std::error_code EC;
1279 directory_iterator Begin(Entry, EC, false);
1280 directory_iterator End;
1281 while (Begin != End) {
1282 auto &Item = *Begin;
1283 ErrorOr<basic_file_status> st = Item.status();
1284 if (st) {
1285 if (is_directory(status: *st)) {
1286 EC = remove_directories_impl(Entry: Item, IgnoreErrors);
1287 if (EC && !IgnoreErrors)
1288 return EC;
1289 }
1290
1291 EC = fs::remove(path: Item.path(), IgnoreNonExisting: true);
1292 if (EC && !IgnoreErrors)
1293 return EC;
1294 } else if (!IgnoreErrors) {
1295 return st.getError();
1296 }
1297
1298 Begin.increment(ec&: EC);
1299 if (EC && !IgnoreErrors)
1300 return EC;
1301 }
1302 return std::error_code();
1303}
1304
1305std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
1306 auto EC = remove_directories_impl(Entry: path, IgnoreErrors);
1307 if (EC && !IgnoreErrors)
1308 return EC;
1309 EC = fs::remove(path, IgnoreNonExisting: true);
1310 if (EC && !IgnoreErrors)
1311 return EC;
1312 return std::error_code();
1313}
1314
1315std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
1316 bool expand_tilde) {
1317 dest.clear();
1318 if (path.isTriviallyEmpty())
1319 return std::error_code();
1320
1321 if (expand_tilde) {
1322 SmallString<128> Storage;
1323 path.toVector(Out&: Storage);
1324 expandTildeExpr(Path&: Storage);
1325 return real_path(path: Storage, dest, expand_tilde: false);
1326 }
1327
1328 SmallString<128> Storage;
1329 StringRef P = path.toNullTerminatedStringRef(Out&: Storage);
1330 char Buffer[PATH_MAX];
1331 if (::realpath(name: P.begin(), resolved: Buffer) == nullptr)
1332 return errnoAsErrorCode();
1333 dest.append(in_start: Buffer, in_end: Buffer + strlen(s: Buffer));
1334 return std::error_code();
1335}
1336
1337std::error_code changeFileOwnership(int FD, uint32_t Owner, uint32_t Group) {
1338 auto FChown = [&]() { return ::fchown(fd: FD, owner: Owner, group: Group); };
1339 // Retry if fchown call fails due to interruption.
1340 if ((sys::RetryAfterSignal(Fail: -1, F: FChown)) < 0)
1341 return errnoAsErrorCode();
1342 return std::error_code();
1343}
1344
1345} // end namespace fs
1346
1347namespace path {
1348
1349bool home_directory(SmallVectorImpl<char> &result) {
1350 std::unique_ptr<char[]> Buf;
1351 char *RequestedDir = getenv(name: "HOME");
1352 if (!RequestedDir) {
1353 long BufSize = sysconf(_SC_GETPW_R_SIZE_MAX);
1354 if (BufSize <= 0)
1355 BufSize = 16384;
1356 Buf = std::make_unique<char[]>(num: BufSize);
1357 struct passwd Pwd;
1358 struct passwd *pw = nullptr;
1359 getpwuid_r(uid: getuid(), resultbuf: &Pwd, buffer: Buf.get(), buflen: BufSize, result: &pw);
1360 if (pw && pw->pw_dir)
1361 RequestedDir = pw->pw_dir;
1362 }
1363 if (!RequestedDir)
1364 return false;
1365
1366 result.clear();
1367 result.append(in_start: RequestedDir, in_end: RequestedDir + strlen(s: RequestedDir));
1368 return true;
1369}
1370
1371static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
1372#if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
1373 // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
1374 // macros defined in <unistd.h> on darwin >= 9
1375 int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR : _CS_DARWIN_USER_CACHE_DIR;
1376 size_t ConfLen = confstr(ConfName, nullptr, 0);
1377 if (ConfLen > 0) {
1378 do {
1379 Result.resize(ConfLen);
1380 ConfLen = confstr(ConfName, Result.data(), Result.size());
1381 } while (ConfLen > 0 && ConfLen != Result.size());
1382
1383 if (ConfLen > 0) {
1384 assert(Result.back() == 0);
1385 Result.pop_back();
1386 return true;
1387 }
1388
1389 Result.clear();
1390 }
1391#endif
1392 return false;
1393}
1394
1395bool user_config_directory(SmallVectorImpl<char> &result) {
1396#ifdef __APPLE__
1397 // Mac: ~/Library/Preferences/
1398 if (home_directory(result)) {
1399 append(result, "Library", "Preferences");
1400 return true;
1401 }
1402#else
1403 // XDG_CONFIG_HOME as defined in the XDG Base Directory Specification:
1404 // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
1405 if (const char *RequestedDir = getenv(name: "XDG_CONFIG_HOME")) {
1406 result.clear();
1407 result.append(in_start: RequestedDir, in_end: RequestedDir + strlen(s: RequestedDir));
1408 return true;
1409 }
1410#endif
1411 // Fallback: ~/.config
1412 if (!home_directory(result)) {
1413 return false;
1414 }
1415 append(path&: result, a: ".config");
1416 return true;
1417}
1418
1419bool cache_directory(SmallVectorImpl<char> &result) {
1420#ifdef __APPLE__
1421 if (getDarwinConfDir(false /*tempDir*/, result)) {
1422 return true;
1423 }
1424#else
1425 // XDG_CACHE_HOME as defined in the XDG Base Directory Specification:
1426 // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
1427 if (const char *RequestedDir = getenv(name: "XDG_CACHE_HOME")) {
1428 result.clear();
1429 result.append(in_start: RequestedDir, in_end: RequestedDir + strlen(s: RequestedDir));
1430 return true;
1431 }
1432#endif
1433 if (!home_directory(result)) {
1434 return false;
1435 }
1436 append(path&: result, a: ".cache");
1437 return true;
1438}
1439
1440static const char *getEnvTempDir() {
1441 // Check whether the temporary directory is specified by an environment
1442 // variable.
1443 const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
1444 for (const char *Env : EnvironmentVariables) {
1445 if (const char *Dir = std::getenv(name: Env))
1446 return Dir;
1447 }
1448
1449 return nullptr;
1450}
1451
1452static const char *getDefaultTempDir(bool ErasedOnReboot) {
1453#ifdef P_tmpdir
1454 if ((bool)P_tmpdir)
1455 return P_tmpdir;
1456#endif
1457
1458 if (ErasedOnReboot)
1459 return "/tmp";
1460 return "/var/tmp";
1461}
1462
1463void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
1464 Result.clear();
1465
1466 if (ErasedOnReboot) {
1467 // There is no env variable for the cache directory.
1468 if (const char *RequestedDir = getEnvTempDir()) {
1469 Result.append(in_start: RequestedDir, in_end: RequestedDir + strlen(s: RequestedDir));
1470 return;
1471 }
1472 }
1473
1474 if (getDarwinConfDir(TempDir: ErasedOnReboot, Result))
1475 return;
1476
1477 const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
1478 Result.append(in_start: RequestedDir, in_end: RequestedDir + strlen(s: RequestedDir));
1479}
1480
1481} // end namespace path
1482
1483namespace fs {
1484
1485#ifdef __APPLE__
1486/// This implementation tries to perform an APFS CoW clone of the file,
1487/// which can be much faster and uses less space.
1488/// Unfortunately fcopyfile(3) does not support COPYFILE_CLONE, so the
1489/// file descriptor variant of this function still uses the default
1490/// implementation.
1491std::error_code copy_file(const Twine &From, const Twine &To) {
1492 std::string FromS = From.str();
1493 std::string ToS = To.str();
1494#if __has_builtin(__builtin_available)
1495 if (__builtin_available(macos 10.12, *)) {
1496 // Optimistically try to use clonefile() and handle errors, rather than
1497 // calling stat() to see if it'll work.
1498 //
1499 // Note: It's okay if From is a symlink. In contrast to the behaviour of
1500 // copyfile() with COPYFILE_CLONE, clonefile() clones targets (not the
1501 // symlink itself) unless the flag CLONE_NOFOLLOW is passed.
1502 if (!clonefile(FromS.c_str(), ToS.c_str(), 0))
1503 return std::error_code();
1504
1505 auto Errno = errno;
1506 switch (Errno) {
1507 case EEXIST: // To already exists.
1508 case ENOTSUP: // Device does not support cloning.
1509 case EXDEV: // From and To are on different devices.
1510 break;
1511 default:
1512 // Anything else will also break copyfile().
1513 return std::error_code(Errno, std::generic_category());
1514 }
1515
1516 // TODO: For EEXIST, profile calling fs::generateUniqueName() and
1517 // clonefile() in a retry loop (then rename() on success) before falling
1518 // back to copyfile(). Depending on the size of the file this could be
1519 // cheaper.
1520 }
1521#endif
1522 if (!copyfile(FromS.c_str(), ToS.c_str(), /*State=*/NULL, COPYFILE_DATA))
1523 return std::error_code();
1524 return errnoAsErrorCode();
1525}
1526#endif // __APPLE__
1527
1528} // end namespace fs
1529
1530} // end namespace sys
1531} // end namespace llvm
1532