1 //===- llvm/Support/Unix/PathV2.cpp - Unix Path Implementation --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Unix specific implementation of the PathV2 API.
12 //===----------------------------------------------------------------------===//
14 //===----------------------------------------------------------------------===//
15 //=== WARNING: Implementation here must contain only generic UNIX code that
16 //=== is guaranteed to work on *all* UNIX variants.
17 //===----------------------------------------------------------------------===//
20 #include "llvm/Support/Process.h"
27 #ifdef HAVE_SYS_MMAN_H
32 # define NAMLEN(dirent) strlen((dirent)->d_name)
34 # define dirent direct
35 # define NAMLEN(dirent) (dirent)->d_namlen
37 # include <sys/ndir.h>
53 // Both stdio.h and cstdio are included via different pathes and
54 // stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
60 #if defined(__GNU__) && !defined(PATH_MAX)
61 # define PATH_MAX 4096
67 /// This class automatically closes the given file descriptor when it goes out
68 /// of scope. You can take back explicit ownership of the file descriptor by
69 /// calling take(). The destructor does not verify that close was successful.
70 /// Therefore, never allow this class to call close on a file descriptor that
71 /// has been read from or written to.
75 AutoFD(int fd) : FileDescriptor(fd) {}
77 if (FileDescriptor >= 0)
78 ::close(FileDescriptor);
82 int ret = FileDescriptor;
87 operator int() const {return FileDescriptor;}
90 error_code TempDir(SmallVectorImpl<char> &result) {
91 // FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
93 (dir = std::getenv("TMPDIR" )) ||
94 (dir = std::getenv("TMP" )) ||
95 (dir = std::getenv("TEMP" )) ||
96 (dir = std::getenv("TEMPDIR")) ||
104 result.append(d.begin(), d.end());
105 return error_code::success();
113 error_code current_path(SmallVectorImpl<char> &result) {
115 result.reserve(MAXPATHLEN);
118 result.reserve(1024);
122 if (::getcwd(result.data(), result.capacity()) == 0) {
123 // See if there was a real error.
124 if (errno != errc::not_enough_memory)
125 return error_code(errno, system_category());
126 // Otherwise there just wasn't enough space.
127 result.reserve(result.capacity() * 2);
132 result.set_size(strlen(result.data()));
133 return error_code::success();
136 error_code copy_file(const Twine &from, const Twine &to, copy_option copt) {
138 SmallString<128> from_storage;
139 SmallString<128> to_storage;
140 StringRef f = from.toNullTerminatedStringRef(from_storage);
141 StringRef t = to.toNullTerminatedStringRef(to_storage);
143 const size_t buf_sz = 32768;
145 int from_file = -1, to_file = -1;
148 if ((from_file = ::open(f.begin(), O_RDONLY)) < 0)
149 return error_code(errno, system_category());
150 AutoFD from_fd(from_file);
153 struct stat from_stat;
154 if (::stat(f.begin(), &from_stat) != 0)
155 return error_code(errno, system_category());
158 int to_flags = O_CREAT | O_WRONLY;
159 if (copt == copy_option::fail_if_exists)
163 if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0)
164 return error_code(errno, system_category());
165 AutoFD to_fd(to_file);
168 ssize_t sz, sz_read = 1, sz_write;
169 while (sz_read > 0 &&
170 (sz_read = ::read(from_fd, buffer, buf_sz)) > 0) {
171 // Allow for partial writes - see Advanced Unix Programming (2nd Ed.),
172 // Marc Rochkind, Addison-Wesley, 2004, page 94
175 if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) {
176 sz_read = sz; // cause read loop termination.
180 } while (sz_write < sz_read);
183 // After all the file operations above the return value of close actually
185 if (::close(from_fd.take()) < 0) sz_read = -1;
186 if (::close(to_fd.take()) < 0) sz_read = -1;
190 return error_code(errno, system_category());
192 return error_code::success();
195 error_code create_directory(const Twine &path, bool &existed) {
196 SmallString<128> path_storage;
197 StringRef p = path.toNullTerminatedStringRef(path_storage);
199 if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
200 if (errno != errc::file_exists)
201 return error_code(errno, system_category());
206 return error_code::success();
209 error_code create_hard_link(const Twine &to, const Twine &from) {
211 SmallString<128> from_storage;
212 SmallString<128> to_storage;
213 StringRef f = from.toNullTerminatedStringRef(from_storage);
214 StringRef t = to.toNullTerminatedStringRef(to_storage);
216 if (::link(t.begin(), f.begin()) == -1)
217 return error_code(errno, system_category());
219 return error_code::success();
222 error_code create_symlink(const Twine &to, const Twine &from) {
224 SmallString<128> from_storage;
225 SmallString<128> to_storage;
226 StringRef f = from.toNullTerminatedStringRef(from_storage);
227 StringRef t = to.toNullTerminatedStringRef(to_storage);
229 if (::symlink(t.begin(), f.begin()) == -1)
230 return error_code(errno, system_category());
232 return error_code::success();
235 error_code remove(const Twine &path, bool &existed) {
236 SmallString<128> path_storage;
237 StringRef p = path.toNullTerminatedStringRef(path_storage);
239 if (::remove(p.begin()) == -1) {
240 if (errno != errc::no_such_file_or_directory)
241 return error_code(errno, system_category());
246 return error_code::success();
249 error_code rename(const Twine &from, const Twine &to) {
251 SmallString<128> from_storage;
252 SmallString<128> to_storage;
253 StringRef f = from.toNullTerminatedStringRef(from_storage);
254 StringRef t = to.toNullTerminatedStringRef(to_storage);
256 if (::rename(f.begin(), t.begin()) == -1) {
257 // If it's a cross device link, copy then delete, otherwise return the error
258 if (errno == EXDEV) {
259 if (error_code ec = copy_file(from, to, copy_option::overwrite_if_exists))
262 if (error_code ec = remove(from, Existed))
265 return error_code(errno, system_category());
268 return error_code::success();
271 error_code resize_file(const Twine &path, uint64_t size) {
272 SmallString<128> path_storage;
273 StringRef p = path.toNullTerminatedStringRef(path_storage);
275 if (::truncate(p.begin(), size) == -1)
276 return error_code(errno, system_category());
278 return error_code::success();
281 error_code exists(const Twine &path, bool &result) {
282 SmallString<128> path_storage;
283 StringRef p = path.toNullTerminatedStringRef(path_storage);
285 if (::access(p.begin(), F_OK) == -1) {
286 if (errno != errc::no_such_file_or_directory)
287 return error_code(errno, system_category());
292 return error_code::success();
295 bool equivalent(file_status A, file_status B) {
296 assert(status_known(A) && status_known(B));
297 return A.fs_st_dev == B.fs_st_dev &&
298 A.fs_st_ino == B.fs_st_ino;
301 error_code equivalent(const Twine &A, const Twine &B, bool &result) {
302 file_status fsA, fsB;
303 if (error_code ec = status(A, fsA)) return ec;
304 if (error_code ec = status(B, fsB)) return ec;
305 result = equivalent(fsA, fsB);
306 return error_code::success();
309 error_code file_size(const Twine &path, uint64_t &result) {
310 SmallString<128> path_storage;
311 StringRef p = path.toNullTerminatedStringRef(path_storage);
314 if (::stat(p.begin(), &status) == -1)
315 return error_code(errno, system_category());
316 if (!S_ISREG(status.st_mode))
317 return make_error_code(errc::operation_not_permitted);
319 result = status.st_size;
320 return error_code::success();
323 error_code status(const Twine &path, file_status &result) {
324 SmallString<128> path_storage;
325 StringRef p = path.toNullTerminatedStringRef(path_storage);
328 if (::stat(p.begin(), &status) != 0) {
329 error_code ec(errno, system_category());
330 if (ec == errc::no_such_file_or_directory)
331 result = file_status(file_type::file_not_found);
333 result = file_status(file_type::status_error);
337 perms prms = static_cast<perms>(status.st_mode & perms_mask);
339 if (S_ISDIR(status.st_mode))
340 result = file_status(file_type::directory_file, prms);
341 else if (S_ISREG(status.st_mode))
342 result = file_status(file_type::regular_file, prms);
343 else if (S_ISBLK(status.st_mode))
344 result = file_status(file_type::block_file, prms);
345 else if (S_ISCHR(status.st_mode))
346 result = file_status(file_type::character_file, prms);
347 else if (S_ISFIFO(status.st_mode))
348 result = file_status(file_type::fifo_file, prms);
349 else if (S_ISSOCK(status.st_mode))
350 result = file_status(file_type::socket_file, prms);
352 result = file_status(file_type::type_unknown, prms);
354 result.fs_st_dev = status.st_dev;
355 result.fs_st_ino = status.st_ino;
357 return error_code::success();
360 // Modifies permissions on a file.
361 error_code permissions(const Twine &path, perms prms) {
362 if ((prms & add_perms) && (prms & remove_perms))
363 llvm_unreachable("add_perms and remove_perms are mutually exclusive");
365 // Get current permissions
367 if (error_code ec = status(path, info)) {
371 // Set updated permissions.
372 SmallString<128> path_storage;
373 StringRef p = path.toNullTerminatedStringRef(path_storage);
375 if (prms & add_perms) {
376 permsToSet = (info.permissions() | prms) & perms_mask;
377 } else if (prms & remove_perms) {
378 permsToSet = (info.permissions() & ~prms) & perms_mask;
380 permsToSet = prms & perms_mask;
382 if (::chmod(p.begin(), static_cast<mode_t>(permsToSet))) {
383 return error_code(errno, system_category());
386 return error_code::success();
389 // Since this is most often used for temporary files, mode defaults to 0600.
390 error_code unique_file(const Twine &model, int &result_fd,
391 SmallVectorImpl<char> &result_path,
392 bool makeAbsolute, unsigned mode) {
393 SmallString<128> Model;
394 model.toVector(Model);
399 // Make model absolute by prepending a temp directory if it's not already.
400 bool absolute = path::is_absolute(Twine(Model));
402 SmallString<128> TDir;
403 if (error_code ec = TempDir(TDir)) return ec;
404 path::append(TDir, Twine(Model));
409 // From here on, DO NOT modify model. It may be needed if the randomly chosen
410 // path already exists.
411 SmallString<128> RandomPath = Model;
414 // Replace '%' with random chars.
415 for (unsigned i = 0, e = Model.size(); i != e; ++i) {
417 RandomPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
420 // Make sure we don't fall into an infinite loop by constantly trying
421 // to create the parent path.
422 bool TriedToCreateParent = false;
424 // Try to open + create the file.
426 int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, mode);
427 if (RandomFD == -1) {
428 int SavedErrno = errno;
429 // If the file existed, try again, otherwise, error.
430 if (SavedErrno == errc::file_exists)
431 goto retry_random_path;
432 // If path prefix doesn't exist, try to create it.
433 if (SavedErrno == errc::no_such_file_or_directory && !TriedToCreateParent) {
434 TriedToCreateParent = true;
435 StringRef p(RandomPath);
436 SmallString<64> dir_to_create;
437 for (path::const_iterator i = path::begin(p),
438 e = --path::end(p); i != e; ++i) {
439 path::append(dir_to_create, *i);
441 if (error_code ec = exists(Twine(dir_to_create), Exists)) return ec;
443 // Don't try to create network paths.
444 if (i->size() > 2 && (*i)[0] == '/' &&
447 return make_error_code(errc::no_such_file_or_directory);
448 if (::mkdir(dir_to_create.c_str(), 0700) == -1 &&
449 errno != errc::file_exists)
450 return error_code(errno, system_category());
453 goto rety_open_create;
456 return error_code(SavedErrno, system_category());
459 // Make the path absolute.
460 char real_path_buff[PATH_MAX + 1];
461 if (realpath(RandomPath.c_str(), real_path_buff) == NULL) {
464 ::unlink(RandomPath.c_str());
465 return error_code(error, system_category());
469 StringRef d(real_path_buff);
470 result_path.append(d.begin(), d.end());
472 result_fd = RandomFD;
473 return error_code::success();
476 error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
481 // Figure out how large the file is.
482 struct stat FileInfo;
483 if (fstat(FD, &FileInfo) == -1)
484 return error_code(errno, system_category());
485 uint64_t FileSize = FileInfo.st_size;
489 else if (FileSize < Size) {
490 // We need to grow the file.
491 if (ftruncate(FD, Size) == -1)
492 return error_code(errno, system_category());
495 int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
496 int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
500 Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
501 if (Mapping == MAP_FAILED)
502 return error_code(errno, system_category());
503 return error_code::success();
506 mapped_file_region::mapped_file_region(const Twine &path,
514 // Make sure that the requested size fits within SIZE_T.
515 if (length > std::numeric_limits<size_t>::max()) {
516 ec = make_error_code(errc::invalid_argument);
520 SmallString<128> path_storage;
521 StringRef name = path.toNullTerminatedStringRef(path_storage);
522 int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
523 int ofd = ::open(name.begin(), oflags);
525 ec = error_code(errno, system_category());
529 ec = init(ofd, true, offset);
534 mapped_file_region::mapped_file_region(int fd,
543 // Make sure that the requested size fits within SIZE_T.
544 if (length > std::numeric_limits<size_t>::max()) {
545 ec = make_error_code(errc::invalid_argument);
549 ec = init(fd, closefd, offset);
554 mapped_file_region::~mapped_file_region() {
556 ::munmap(Mapping, Size);
559 #if LLVM_HAS_RVALUE_REFERENCES
560 mapped_file_region::mapped_file_region(mapped_file_region &&other)
561 : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
566 mapped_file_region::mapmode mapped_file_region::flags() const {
567 assert(Mapping && "Mapping failed but used anyway!");
571 uint64_t mapped_file_region::size() const {
572 assert(Mapping && "Mapping failed but used anyway!");
576 char *mapped_file_region::data() const {
577 assert(Mapping && "Mapping failed but used anyway!");
578 assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
579 return reinterpret_cast<char*>(Mapping);
582 const char *mapped_file_region::const_data() const {
583 assert(Mapping && "Mapping failed but used anyway!");
584 return reinterpret_cast<const char*>(Mapping);
587 int mapped_file_region::alignment() {
588 return process::get_self()->page_size();
591 error_code detail::directory_iterator_construct(detail::DirIterState &it,
593 SmallString<128> path_null(path);
594 DIR *directory = ::opendir(path_null.c_str());
596 return error_code(errno, system_category());
598 it.IterationHandle = reinterpret_cast<intptr_t>(directory);
599 // Add something for replace_filename to replace.
600 path::append(path_null, ".");
601 it.CurrentEntry = directory_entry(path_null.str());
602 return directory_iterator_increment(it);
605 error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
606 if (it.IterationHandle)
607 ::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
608 it.IterationHandle = 0;
609 it.CurrentEntry = directory_entry();
610 return error_code::success();
613 error_code detail::directory_iterator_increment(detail::DirIterState &it) {
615 dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
616 if (cur_dir == 0 && errno != 0) {
617 return error_code(errno, system_category());
618 } else if (cur_dir != 0) {
619 StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
620 if ((name.size() == 1 && name[0] == '.') ||
621 (name.size() == 2 && name[0] == '.' && name[1] == '.'))
622 return directory_iterator_increment(it);
623 it.CurrentEntry.replace_filename(name);
625 return directory_iterator_destruct(it);
627 return error_code::success();
630 error_code get_magic(const Twine &path, uint32_t len,
631 SmallVectorImpl<char> &result) {
632 SmallString<128> PathStorage;
633 StringRef Path = path.toNullTerminatedStringRef(PathStorage);
637 std::FILE *file = std::fopen(Path.data(), "rb");
639 return error_code(errno, system_category());
645 size_t size = std::fread(result.data(), 1, len, file);
646 if (std::ferror(file) != 0) {
648 return error_code(errno, system_category());
649 } else if (size != result.size()) {
650 if (std::feof(file) != 0) {
652 result.set_size(size);
653 return make_error_code(errc::value_too_large);
657 result.set_size(len);
658 return error_code::success();
661 error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,
662 bool map_writable, void *&result) {
663 SmallString<128> path_storage;
664 StringRef name = path.toNullTerminatedStringRef(path_storage);
665 int oflags = map_writable ? O_RDWR : O_RDONLY;
666 int ofd = ::open(name.begin(), oflags);
668 return error_code(errno, system_category());
670 int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
671 int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
675 result = ::mmap(0, size, prot, flags, fd, file_offset);
676 if (result == MAP_FAILED) {
677 return error_code(errno, system_category());
680 return error_code::success();
683 error_code unmap_file_pages(void *base, size_t size) {
684 if ( ::munmap(base, size) == -1 )
685 return error_code(errno, system_category());
687 return error_code::success();
691 } // end namespace fs
692 } // end namespace sys
693 } // end namespace llvm