1 //===- llvm/Support/Unix/PathV2.cpp - Unix Path Implementation --*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the Unix specific implementation of the PathV2 API. 11 // 12 //===----------------------------------------------------------------------===// 13 14 //===----------------------------------------------------------------------===// 15 //=== WARNING: Implementation here must contain only generic UNIX code that 16 //=== is guaranteed to work on *all* UNIX variants. 17 //===----------------------------------------------------------------------===// 18 19 #include "Unix.h" 20 #include "llvm/Support/Process.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_SYS_MMAN_H 28 #include <sys/mman.h> 29 #endif 30 #if HAVE_DIRENT_H 31 # include <dirent.h> 32 # define NAMLEN(dirent) strlen((dirent)->d_name) 33 #else 34 # define dirent direct 35 # define NAMLEN(dirent) (dirent)->d_namlen 36 # if HAVE_SYS_NDIR_H 37 # include <sys/ndir.h> 38 # endif 39 # if HAVE_SYS_DIR_H 40 # include <sys/dir.h> 41 # endif 42 # if HAVE_NDIR_H 43 # include <ndir.h> 44 # endif 45 #endif 46 #if HAVE_STDIO_H 47 #include <stdio.h> 48 #endif 49 #if HAVE_LIMITS_H 50 #include <limits.h> 51 #endif 52 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 55 // either. 56 #undef ferror 57 #undef feof 58 59 // For GNU Hurd 60 #if defined(__GNU__) && !defined(PATH_MAX) 61 # define PATH_MAX 4096 62 #endif 63 64 extern "C" int truncate (const char*, off_t); 65 66 using namespace llvm; 67 68 namespace { 69 /// This class automatically closes the given file descriptor when it goes out 70 /// of scope. You can take back explicit ownership of the file descriptor by 71 /// calling take(). The destructor does not verify that close was successful. 72 /// Therefore, never allow this class to call close on a file descriptor that 73 /// has been read from or written to. 74 struct AutoFD { 75 int FileDescriptor; 76 77 AutoFD(int fd) : FileDescriptor(fd) {} 78 ~AutoFD() { 79 if (FileDescriptor >= 0) 80 ::close(FileDescriptor); 81 } 82 83 int take() { 84 int ret = FileDescriptor; 85 FileDescriptor = -1; 86 return ret; 87 } 88 89 operator int() const {return FileDescriptor;} 90 }; 91 92 error_code TempDir(SmallVectorImpl<char> &result) { 93 // FIXME: Don't use TMPDIR if program is SUID or SGID enabled. 94 const char *dir = 0; 95 (dir = std::getenv("TMPDIR" )) || 96 (dir = std::getenv("TMP" )) || 97 (dir = std::getenv("TEMP" )) || 98 (dir = std::getenv("TEMPDIR")) || 99 #ifdef P_tmpdir 100 (dir = P_tmpdir) || 101 #endif 102 (dir = "/tmp"); 103 104 result.clear(); 105 StringRef d(dir); 106 result.append(d.begin(), d.end()); 107 return error_code::success(); 108 } 109 } 110 111 namespace llvm { 112 namespace sys { 113 namespace fs { 114 115 error_code current_path(SmallVectorImpl<char> &result) { 116 #ifdef MAXPATHLEN 117 result.reserve(MAXPATHLEN); 118 #else 119 // For GNU Hurd 120 result.reserve(1024); 121 #endif 122 123 while (true) { 124 if (::getcwd(result.data(), result.capacity()) == 0) { 125 // See if there was a real error. 126 if (errno != errc::not_enough_memory) 127 return error_code(errno, system_category()); 128 // Otherwise there just wasn't enough space. 129 result.reserve(result.capacity() * 2); 130 } else 131 break; 132 } 133 134 result.set_size(strlen(result.data())); 135 return error_code::success(); 136 } 137 138 error_code copy_file(const Twine &from, const Twine &to, copy_option copt) { 139 // Get arguments. 140 SmallString<128> from_storage; 141 SmallString<128> to_storage; 142 StringRef f = from.toNullTerminatedStringRef(from_storage); 143 StringRef t = to.toNullTerminatedStringRef(to_storage); 144 145 const size_t buf_sz = 32768; 146 char buffer[buf_sz]; 147 int from_file = -1, to_file = -1; 148 149 // Open from. 150 if ((from_file = ::open(f.begin(), O_RDONLY)) < 0) 151 return error_code(errno, system_category()); 152 AutoFD from_fd(from_file); 153 154 // Stat from. 155 struct stat from_stat; 156 if (::stat(f.begin(), &from_stat) != 0) 157 return error_code(errno, system_category()); 158 159 // Setup to flags. 160 int to_flags = O_CREAT | O_WRONLY; 161 if (copt == copy_option::fail_if_exists) 162 to_flags |= O_EXCL; 163 164 // Open to. 165 if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0) 166 return error_code(errno, system_category()); 167 AutoFD to_fd(to_file); 168 169 // Copy! 170 ssize_t sz, sz_read = 1, sz_write; 171 while (sz_read > 0 && 172 (sz_read = ::read(from_fd, buffer, buf_sz)) > 0) { 173 // Allow for partial writes - see Advanced Unix Programming (2nd Ed.), 174 // Marc Rochkind, Addison-Wesley, 2004, page 94 175 sz_write = 0; 176 do { 177 if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) { 178 sz_read = sz; // cause read loop termination. 179 break; // error. 180 } 181 sz_write += sz; 182 } while (sz_write < sz_read); 183 } 184 185 // After all the file operations above the return value of close actually 186 // matters. 187 if (::close(from_fd.take()) < 0) sz_read = -1; 188 if (::close(to_fd.take()) < 0) sz_read = -1; 189 190 // Check for errors. 191 if (sz_read < 0) 192 return error_code(errno, system_category()); 193 194 return error_code::success(); 195 } 196 197 error_code create_directory(const Twine &path, bool &existed) { 198 SmallString<128> path_storage; 199 StringRef p = path.toNullTerminatedStringRef(path_storage); 200 201 if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) { 202 if (errno != errc::file_exists) 203 return error_code(errno, system_category()); 204 existed = true; 205 } else 206 existed = false; 207 208 return error_code::success(); 209 } 210 211 error_code create_hard_link(const Twine &to, const Twine &from) { 212 // Get arguments. 213 SmallString<128> from_storage; 214 SmallString<128> to_storage; 215 StringRef f = from.toNullTerminatedStringRef(from_storage); 216 StringRef t = to.toNullTerminatedStringRef(to_storage); 217 218 if (::link(t.begin(), f.begin()) == -1) 219 return error_code(errno, system_category()); 220 221 return error_code::success(); 222 } 223 224 error_code create_symlink(const Twine &to, const Twine &from) { 225 // Get arguments. 226 SmallString<128> from_storage; 227 SmallString<128> to_storage; 228 StringRef f = from.toNullTerminatedStringRef(from_storage); 229 StringRef t = to.toNullTerminatedStringRef(to_storage); 230 231 if (::symlink(t.begin(), f.begin()) == -1) 232 return error_code(errno, system_category()); 233 234 return error_code::success(); 235 } 236 237 error_code remove(const Twine &path, bool &existed) { 238 SmallString<128> path_storage; 239 StringRef p = path.toNullTerminatedStringRef(path_storage); 240 241 if (::remove(p.begin()) == -1) { 242 if (errno != errc::no_such_file_or_directory) 243 return error_code(errno, system_category()); 244 existed = false; 245 } else 246 existed = true; 247 248 return error_code::success(); 249 } 250 251 error_code rename(const Twine &from, const Twine &to) { 252 // Get arguments. 253 SmallString<128> from_storage; 254 SmallString<128> to_storage; 255 StringRef f = from.toNullTerminatedStringRef(from_storage); 256 StringRef t = to.toNullTerminatedStringRef(to_storage); 257 258 if (::rename(f.begin(), t.begin()) == -1) { 259 // If it's a cross device link, copy then delete, otherwise return the error 260 if (errno == EXDEV) { 261 if (error_code ec = copy_file(from, to, copy_option::overwrite_if_exists)) 262 return ec; 263 bool Existed; 264 if (error_code ec = remove(from, Existed)) 265 return ec; 266 } else 267 return error_code(errno, system_category()); 268 } 269 270 return error_code::success(); 271 } 272 273 error_code resize_file(const Twine &path, uint64_t size) { 274 SmallString<128> path_storage; 275 StringRef p = path.toNullTerminatedStringRef(path_storage); 276 277 if (::truncate(p.begin(), size) == -1) 278 return error_code(errno, system_category()); 279 280 return error_code::success(); 281 } 282 283 error_code exists(const Twine &path, bool &result) { 284 SmallString<128> path_storage; 285 StringRef p = path.toNullTerminatedStringRef(path_storage); 286 287 if (::access(p.begin(), F_OK) == -1) { 288 if (errno != errc::no_such_file_or_directory) 289 return error_code(errno, system_category()); 290 result = false; 291 } else 292 result = true; 293 294 return error_code::success(); 295 } 296 297 bool equivalent(file_status A, file_status B) { 298 assert(status_known(A) && status_known(B)); 299 return A.fs_st_dev == B.fs_st_dev && 300 A.fs_st_ino == B.fs_st_ino; 301 } 302 303 error_code equivalent(const Twine &A, const Twine &B, bool &result) { 304 file_status fsA, fsB; 305 if (error_code ec = status(A, fsA)) return ec; 306 if (error_code ec = status(B, fsB)) return ec; 307 result = equivalent(fsA, fsB); 308 return error_code::success(); 309 } 310 311 error_code file_size(const Twine &path, uint64_t &result) { 312 SmallString<128> path_storage; 313 StringRef p = path.toNullTerminatedStringRef(path_storage); 314 315 struct stat status; 316 if (::stat(p.begin(), &status) == -1) 317 return error_code(errno, system_category()); 318 if (!S_ISREG(status.st_mode)) 319 return make_error_code(errc::operation_not_permitted); 320 321 result = status.st_size; 322 return error_code::success(); 323 } 324 325 error_code status(const Twine &path, file_status &result) { 326 SmallString<128> path_storage; 327 StringRef p = path.toNullTerminatedStringRef(path_storage); 328 329 struct stat status; 330 if (::stat(p.begin(), &status) != 0) { 331 error_code ec(errno, system_category()); 332 if (ec == errc::no_such_file_or_directory) 333 result = file_status(file_type::file_not_found); 334 else 335 result = file_status(file_type::status_error); 336 return ec; 337 } 338 339 perms prms = static_cast<perms>(status.st_mode & perms_mask); 340 341 if (S_ISDIR(status.st_mode)) 342 result = file_status(file_type::directory_file, prms); 343 else if (S_ISREG(status.st_mode)) 344 result = file_status(file_type::regular_file, prms); 345 else if (S_ISBLK(status.st_mode)) 346 result = file_status(file_type::block_file, prms); 347 else if (S_ISCHR(status.st_mode)) 348 result = file_status(file_type::character_file, prms); 349 else if (S_ISFIFO(status.st_mode)) 350 result = file_status(file_type::fifo_file, prms); 351 else if (S_ISSOCK(status.st_mode)) 352 result = file_status(file_type::socket_file, prms); 353 else 354 result = file_status(file_type::type_unknown, prms); 355 356 result.fs_st_dev = status.st_dev; 357 result.fs_st_ino = status.st_ino; 358 359 return error_code::success(); 360 } 361 362 // Modifies permissions on a file. 363 error_code permissions(const Twine &path, perms prms) { 364 if ((prms & add_perms) && (prms & remove_perms)) 365 llvm_unreachable("add_perms and remove_perms are mutually exclusive"); 366 367 // Get current permissions 368 file_status info; 369 if (error_code ec = status(path, info)) { 370 return ec; 371 } 372 373 // Set updated permissions. 374 SmallString<128> path_storage; 375 StringRef p = path.toNullTerminatedStringRef(path_storage); 376 perms permsToSet; 377 if (prms & add_perms) { 378 permsToSet = (info.permissions() | prms) & perms_mask; 379 } else if (prms & remove_perms) { 380 permsToSet = (info.permissions() & ~prms) & perms_mask; 381 } else { 382 permsToSet = prms & perms_mask; 383 } 384 if (::chmod(p.begin(), static_cast<mode_t>(permsToSet))) { 385 return error_code(errno, system_category()); 386 } 387 388 return error_code::success(); 389 } 390 391 // Since this is most often used for temporary files, mode defaults to 0600. 392 error_code unique_file(const Twine &model, int &result_fd, 393 SmallVectorImpl<char> &result_path, 394 bool makeAbsolute, unsigned mode) { 395 SmallString<128> Model; 396 model.toVector(Model); 397 // Null terminate. 398 Model.c_str(); 399 400 if (makeAbsolute) { 401 // Make model absolute by prepending a temp directory if it's not already. 402 bool absolute = path::is_absolute(Twine(Model)); 403 if (!absolute) { 404 SmallString<128> TDir; 405 if (error_code ec = TempDir(TDir)) return ec; 406 path::append(TDir, Twine(Model)); 407 Model.swap(TDir); 408 } 409 } 410 411 // From here on, DO NOT modify model. It may be needed if the randomly chosen 412 // path already exists. 413 SmallString<128> RandomPath = Model; 414 415 retry_random_path: 416 // Replace '%' with random chars. 417 for (unsigned i = 0, e = Model.size(); i != e; ++i) { 418 if (Model[i] == '%') 419 RandomPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15]; 420 } 421 422 // Try to open + create the file. 423 rety_open_create: 424 int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, mode); 425 if (RandomFD == -1) { 426 // If the file existed, try again, otherwise, error. 427 if (errno == errc::file_exists) 428 goto retry_random_path; 429 // The path prefix doesn't exist. 430 if (errno == errc::no_such_file_or_directory) { 431 StringRef p(RandomPath.begin(), RandomPath.size()); 432 SmallString<64> dir_to_create; 433 for (path::const_iterator i = path::begin(p), 434 e = --path::end(p); i != e; ++i) { 435 path::append(dir_to_create, *i); 436 bool Exists; 437 if (error_code ec = exists(Twine(dir_to_create), Exists)) return ec; 438 if (!Exists) { 439 // Don't try to create network paths. 440 if (i->size() > 2 && (*i)[0] == '/' && 441 (*i)[1] == '/' && 442 (*i)[2] != '/') 443 return make_error_code(errc::no_such_file_or_directory); 444 if (::mkdir(dir_to_create.c_str(), 0700) == -1) 445 return error_code(errno, system_category()); 446 } 447 } 448 goto rety_open_create; 449 } 450 return error_code(errno, system_category()); 451 } 452 453 // Make the path absolute. 454 char real_path_buff[PATH_MAX + 1]; 455 if (realpath(RandomPath.c_str(), real_path_buff) == NULL) { 456 int error = errno; 457 ::close(RandomFD); 458 ::unlink(RandomPath.c_str()); 459 return error_code(error, system_category()); 460 } 461 462 result_path.clear(); 463 StringRef d(real_path_buff); 464 result_path.append(d.begin(), d.end()); 465 466 result_fd = RandomFD; 467 return error_code::success(); 468 } 469 470 error_code mapped_file_region::init(int fd, uint64_t offset) { 471 AutoFD FD(fd); 472 473 // Figure out how large the file is. 474 struct stat FileInfo; 475 if (fstat(fd, &FileInfo) == -1) 476 return error_code(errno, system_category()); 477 uint64_t FileSize = FileInfo.st_size; 478 479 if (Size == 0) 480 Size = FileSize; 481 else if (FileSize < Size) { 482 // We need to grow the file. 483 if (ftruncate(fd, Size) == -1) 484 return error_code(errno, system_category()); 485 } 486 487 int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE; 488 int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE); 489 #ifdef MAP_FILE 490 flags |= MAP_FILE; 491 #endif 492 Mapping = ::mmap(0, Size, prot, flags, fd, offset); 493 if (Mapping == MAP_FAILED) 494 return error_code(errno, system_category()); 495 return error_code::success(); 496 } 497 498 mapped_file_region::mapped_file_region(const Twine &path, 499 mapmode mode, 500 uint64_t length, 501 uint64_t offset, 502 error_code &ec) 503 : Mode(mode) 504 , Size(length) 505 , Mapping() { 506 // Make sure that the requested size fits within SIZE_T. 507 if (length > std::numeric_limits<size_t>::max()) { 508 ec = make_error_code(errc::invalid_argument); 509 return; 510 } 511 512 SmallString<128> path_storage; 513 StringRef name = path.toNullTerminatedStringRef(path_storage); 514 int oflags = (mode == readonly) ? O_RDONLY : O_RDWR; 515 int ofd = ::open(name.begin(), oflags); 516 if (ofd == -1) { 517 ec = error_code(errno, system_category()); 518 return; 519 } 520 521 ec = init(ofd, offset); 522 if (ec) 523 Mapping = 0; 524 } 525 526 mapped_file_region::mapped_file_region(int fd, 527 mapmode mode, 528 uint64_t length, 529 uint64_t offset, 530 error_code &ec) 531 : Mode(mode) 532 , Size(length) 533 , Mapping() { 534 // Make sure that the requested size fits within SIZE_T. 535 if (length > std::numeric_limits<size_t>::max()) { 536 ec = make_error_code(errc::invalid_argument); 537 return; 538 } 539 540 ec = init(fd, offset); 541 if (ec) 542 Mapping = 0; 543 } 544 545 mapped_file_region::~mapped_file_region() { 546 if (Mapping) 547 ::munmap(Mapping, Size); 548 } 549 550 #if LLVM_USE_RVALUE_REFERENCES 551 mapped_file_region::mapped_file_region(mapped_file_region &&other) 552 : Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) { 553 other.Mapping = 0; 554 } 555 #endif 556 557 mapped_file_region::mapmode mapped_file_region::flags() const { 558 assert(Mapping && "Mapping failed but used anyway!"); 559 return Mode; 560 } 561 562 uint64_t mapped_file_region::size() const { 563 assert(Mapping && "Mapping failed but used anyway!"); 564 return Size; 565 } 566 567 char *mapped_file_region::data() const { 568 assert(Mapping && "Mapping failed but used anyway!"); 569 assert(Mode != readonly && "Cannot get non const data for readonly mapping!"); 570 return reinterpret_cast<char*>(Mapping); 571 } 572 573 const char *mapped_file_region::const_data() const { 574 assert(Mapping && "Mapping failed but used anyway!"); 575 return reinterpret_cast<const char*>(Mapping); 576 } 577 578 int mapped_file_region::alignment() { 579 return Process::GetPageSize(); 580 } 581 582 error_code detail::directory_iterator_construct(detail::DirIterState &it, 583 StringRef path){ 584 SmallString<128> path_null(path); 585 DIR *directory = ::opendir(path_null.c_str()); 586 if (directory == 0) 587 return error_code(errno, system_category()); 588 589 it.IterationHandle = reinterpret_cast<intptr_t>(directory); 590 // Add something for replace_filename to replace. 591 path::append(path_null, "."); 592 it.CurrentEntry = directory_entry(path_null.str()); 593 return directory_iterator_increment(it); 594 } 595 596 error_code detail::directory_iterator_destruct(detail::DirIterState &it) { 597 if (it.IterationHandle) 598 ::closedir(reinterpret_cast<DIR *>(it.IterationHandle)); 599 it.IterationHandle = 0; 600 it.CurrentEntry = directory_entry(); 601 return error_code::success(); 602 } 603 604 error_code detail::directory_iterator_increment(detail::DirIterState &it) { 605 errno = 0; 606 dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle)); 607 if (cur_dir == 0 && errno != 0) { 608 return error_code(errno, system_category()); 609 } else if (cur_dir != 0) { 610 StringRef name(cur_dir->d_name, NAMLEN(cur_dir)); 611 if ((name.size() == 1 && name[0] == '.') || 612 (name.size() == 2 && name[0] == '.' && name[1] == '.')) 613 return directory_iterator_increment(it); 614 it.CurrentEntry.replace_filename(name); 615 } else 616 return directory_iterator_destruct(it); 617 618 return error_code::success(); 619 } 620 621 error_code get_magic(const Twine &path, uint32_t len, 622 SmallVectorImpl<char> &result) { 623 SmallString<128> PathStorage; 624 StringRef Path = path.toNullTerminatedStringRef(PathStorage); 625 result.set_size(0); 626 627 // Open path. 628 std::FILE *file = std::fopen(Path.data(), "rb"); 629 if (file == 0) 630 return error_code(errno, system_category()); 631 632 // Reserve storage. 633 result.reserve(len); 634 635 // Read magic! 636 size_t size = std::fread(result.data(), 1, len, file); 637 if (std::ferror(file) != 0) { 638 std::fclose(file); 639 return error_code(errno, system_category()); 640 } else if (size != result.size()) { 641 if (std::feof(file) != 0) { 642 std::fclose(file); 643 result.set_size(size); 644 return make_error_code(errc::value_too_large); 645 } 646 } 647 std::fclose(file); 648 result.set_size(len); 649 return error_code::success(); 650 } 651 652 error_code map_file_pages(const Twine &path, off_t file_offset, size_t size, 653 bool map_writable, void *&result) { 654 SmallString<128> path_storage; 655 StringRef name = path.toNullTerminatedStringRef(path_storage); 656 int oflags = map_writable ? O_RDWR : O_RDONLY; 657 int ofd = ::open(name.begin(), oflags); 658 if ( ofd == -1 ) 659 return error_code(errno, system_category()); 660 AutoFD fd(ofd); 661 int flags = map_writable ? MAP_SHARED : MAP_PRIVATE; 662 int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ; 663 #ifdef MAP_FILE 664 flags |= MAP_FILE; 665 #endif 666 result = ::mmap(0, size, prot, flags, fd, file_offset); 667 if (result == MAP_FAILED) { 668 return error_code(errno, system_category()); 669 } 670 671 return error_code::success(); 672 } 673 674 error_code unmap_file_pages(void *base, size_t size) { 675 if ( ::munmap(base, size) == -1 ) 676 return error_code(errno, system_category()); 677 678 return error_code::success(); 679 } 680 681 682 } // end namespace fs 683 } // end namespace sys 684 } // end namespace llvm 685
