1//===- llvm/Support/Unix/Path.inc - 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 Path 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 <limits.h> 21#include <stdio.h> 22#if HAVE_SYS_STAT_H 23#include <sys/stat.h> 24#endif 25#if HAVE_FCNTL_H 26#include <fcntl.h> 27#endif 28#ifdef HAVE_UNISTD_H 29#include <unistd.h> 30#endif 31#ifdef HAVE_SYS_MMAN_H 32#include <sys/mman.h> 33#endif 34#if HAVE_DIRENT_H 35# include <dirent.h> 36# define NAMLEN(dirent) strlen((dirent)->d_name) 37#else 38# define dirent direct 39# define NAMLEN(dirent) (dirent)->d_namlen 40# if HAVE_SYS_NDIR_H 41# include <sys/ndir.h> 42# endif 43# if HAVE_SYS_DIR_H 44# include <sys/dir.h> 45# endif 46# if HAVE_NDIR_H 47# include <ndir.h> 48# endif 49#endif 50 51#ifdef __APPLE__ 52#include <mach-o/dyld.h> 53#include <sys/attr.h> 54#endif 55 56// Both stdio.h and cstdio are included via different paths and 57// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros 58// either. 59#undef ferror 60#undef feof 61 62// For GNU Hurd 63#if defined(__GNU__) && !defined(PATH_MAX) 64# define PATH_MAX 4096 65#endif 66 67#include <sys/types.h> 68#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && \ 69 !defined(__linux__) 70#include <sys/statvfs.h> 71#define STATVFS statvfs 72#define FSTATVFS fstatvfs 73#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize 74#else 75#if defined(__OpenBSD__) || defined(__FreeBSD__) 76#include <sys/param.h> 77#include <sys/mount.h> 78#elif defined(__linux__) 79#if defined(HAVE_LINUX_MAGIC_H) 80#include <linux/magic.h> 81#else 82#if defined(HAVE_LINUX_NFS_FS_H) 83#include <linux/nfs_fs.h> 84#endif 85#if defined(HAVE_LINUX_SMB_H) 86#include <linux/smb.h> 87#endif 88#endif 89#include <sys/vfs.h> 90#else 91#include <sys/mount.h> 92#endif 93#define STATVFS statfs 94#define FSTATVFS fstatfs 95#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize) 96#endif 97 98#if defined(__NetBSD__) 99#define STATVFS_F_FLAG(vfs) (vfs).f_flag 100#else 101#define STATVFS_F_FLAG(vfs) (vfs).f_flags 102#endif 103 104using namespace llvm; 105 106namespace llvm { 107namespace sys { 108namespace fs { 109#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \ 110 defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \ 111 defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__) || \ 112 defined(_AIX) 113static int 114test_dir(char ret[PATH_MAX], const char *dir, const char *bin) 115{ 116 struct stat sb; 117 char fullpath[PATH_MAX]; 118 119 snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin); 120 if (!realpath(fullpath, ret)) 121 return 1; 122 if (stat(fullpath, &sb) != 0) 123 return 1; 124 125 return 0; 126} 127 128static char * 129getprogpath(char ret[PATH_MAX], const char *bin) 130{ 131 char *pv, *s, *t; 132 133 /* First approach: absolute path. */ 134 if (bin[0] == '/') { 135 if (test_dir(ret, "/", bin) == 0) 136 return ret; 137 return nullptr; 138 } 139 140 /* Second approach: relative path. */ 141 if (strchr(bin, '/')) { 142 char cwd[PATH_MAX]; 143 if (!getcwd(cwd, PATH_MAX)) 144 return nullptr; 145 if (test_dir(ret, cwd, bin) == 0) 146 return ret; 147 return nullptr; 148 } 149 150 /* Third approach: $PATH */ 151 if ((pv = getenv("PATH")) == nullptr) 152 return nullptr; 153 s = pv = strdup(pv); 154 if (!pv) 155 return nullptr; 156 while ((t = strsep(&s, ":")) != nullptr) { 157 if (test_dir(ret, t, bin) == 0) { 158 free(pv); 159 return ret; 160 } 161 } 162 free(pv); 163 return nullptr; 164} 165#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__ 166 167/// GetMainExecutable - Return the path to the main executable, given the 168/// value of argv[0] from program startup. 169std::string getMainExecutable(const char *argv0, void *MainAddr) { 170#if defined(__APPLE__) 171 // On OS X the executable path is saved to the stack by dyld. Reading it 172 // from there is much faster than calling dladdr, especially for large 173 // binaries with symbols. 174 char exe_path[MAXPATHLEN]; 175 uint32_t size = sizeof(exe_path); 176 if (_NSGetExecutablePath(exe_path, &size) == 0) { 177 char link_path[MAXPATHLEN]; 178 if (realpath(exe_path, link_path)) 179 return link_path; 180 } 181#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \ 182 defined(__OpenBSD__) || defined(__minix) || defined(__DragonFly__) || \ 183 defined(__FreeBSD_kernel__) || defined(_AIX) 184 char exe_path[PATH_MAX]; 185 186 if (getprogpath(exe_path, argv0) != NULL) 187 return exe_path; 188#elif defined(__linux__) || defined(__CYGWIN__) 189 char exe_path[MAXPATHLEN]; 190 StringRef aPath("/proc/self/exe"); 191 if (sys::fs::exists(aPath)) { 192 // /proc is not always mounted under Linux (chroot for example). 193 ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path)); 194 if (len >= 0) 195 return std::string(exe_path, len); 196 } else { 197 // Fall back to the classical detection. 198 if (getprogpath(exe_path, argv0)) 199 return exe_path; 200 } 201#elif defined(HAVE_DLFCN_H) && defined(HAVE_DLADDR) 202 // Use dladdr to get executable path if available. 203 Dl_info DLInfo; 204 int err = dladdr(MainAddr, &DLInfo); 205 if (err == 0) 206 return ""; 207 208 // If the filename is a symlink, we need to resolve and return the location of 209 // the actual executable. 210 char link_path[MAXPATHLEN]; 211 if (realpath(DLInfo.dli_fname, link_path)) 212 return link_path; 213#else 214#error GetMainExecutable is not implemented on this host yet. 215#endif 216 return ""; 217} 218 219TimePoint<> file_status::getLastAccessedTime() const { 220 return toTimePoint(fs_st_atime); 221} 222 223TimePoint<> file_status::getLastModificationTime() const { 224 return toTimePoint(fs_st_mtime); 225} 226 227UniqueID file_status::getUniqueID() const { 228 return UniqueID(fs_st_dev, fs_st_ino); 229} 230 231ErrorOr<space_info> disk_space(const Twine &Path) { 232 struct STATVFS Vfs; 233 if (::STATVFS(Path.str().c_str(), &Vfs)) 234 return std::error_code(errno, std::generic_category()); 235 auto FrSize = STATVFS_F_FRSIZE(Vfs); 236 space_info SpaceInfo; 237 SpaceInfo.capacity = static_cast<uint64_t>(Vfs.f_blocks) * FrSize; 238 SpaceInfo.free = static_cast<uint64_t>(Vfs.f_bfree) * FrSize; 239 SpaceInfo.available = static_cast<uint64_t>(Vfs.f_bavail) * FrSize; 240 return SpaceInfo; 241} 242 243std::error_code current_path(SmallVectorImpl<char> &result) { 244 result.clear(); 245 246 const char *pwd = ::getenv("PWD"); 247 llvm::sys::fs::file_status PWDStatus, DotStatus; 248 if (pwd && llvm::sys::path::is_absolute(pwd) && 249 !llvm::sys::fs::status(pwd, PWDStatus) && 250 !llvm::sys::fs::status(".", DotStatus) && 251 PWDStatus.getUniqueID() == DotStatus.getUniqueID()) { 252 result.append(pwd, pwd + strlen(pwd)); 253 return std::error_code(); 254 } 255 256#ifdef MAXPATHLEN 257 result.reserve(MAXPATHLEN); 258#else 259// For GNU Hurd 260 result.reserve(1024); 261#endif 262 263 while (true) { 264 if (::getcwd(result.data(), result.capacity()) == nullptr) { 265 // See if there was a real error. 266 if (errno != ENOMEM) 267 return std::error_code(errno, std::generic_category()); 268 // Otherwise there just wasn't enough space. 269 result.reserve(result.capacity() * 2); 270 } else 271 break; 272 } 273 274 result.set_size(strlen(result.data())); 275 return std::error_code(); 276} 277 278std::error_code set_current_path(const Twine &path) { 279 SmallString<128> path_storage; 280 StringRef p = path.toNullTerminatedStringRef(path_storage); 281 282 if (::chdir(p.begin()) == -1) 283 return std::error_code(errno, std::generic_category()); 284 285 return std::error_code(); 286} 287 288std::error_code create_directory(const Twine &path, bool IgnoreExisting, 289 perms Perms) { 290 SmallString<128> path_storage; 291 StringRef p = path.toNullTerminatedStringRef(path_storage); 292 293 if (::mkdir(p.begin(), Perms) == -1) { 294 if (errno != EEXIST || !IgnoreExisting) 295 return std::error_code(errno, std::generic_category()); 296 } 297 298 return std::error_code(); 299} 300 301// Note that we are using symbolic link because hard links are not supported by 302// all filesystems (SMB doesn't). 303std::error_code create_link(const Twine &to, const Twine &from) { 304 // Get arguments. 305 SmallString<128> from_storage; 306 SmallString<128> to_storage; 307 StringRef f = from.toNullTerminatedStringRef(from_storage); 308 StringRef t = to.toNullTerminatedStringRef(to_storage); 309 310 if (::symlink(t.begin(), f.begin()) == -1) 311 return std::error_code(errno, std::generic_category()); 312 313 return std::error_code(); 314} 315 316std::error_code create_hard_link(const Twine &to, const Twine &from) { 317 // Get arguments. 318 SmallString<128> from_storage; 319 SmallString<128> to_storage; 320 StringRef f = from.toNullTerminatedStringRef(from_storage); 321 StringRef t = to.toNullTerminatedStringRef(to_storage); 322 323 if (::link(t.begin(), f.begin()) == -1) 324 return std::error_code(errno, std::generic_category()); 325 326 return std::error_code(); 327} 328 329std::error_code remove(const Twine &path, bool IgnoreNonExisting) { 330 SmallString<128> path_storage; 331 StringRef p = path.toNullTerminatedStringRef(path_storage); 332 333 struct stat buf; 334 if (lstat(p.begin(), &buf) != 0) { 335 if (errno != ENOENT || !IgnoreNonExisting) 336 return std::error_code(errno, std::generic_category()); 337 return std::error_code(); 338 } 339 340 // Note: this check catches strange situations. In all cases, LLVM should 341 // only be involved in the creation and deletion of regular files. This 342 // check ensures that what we're trying to erase is a regular file. It 343 // effectively prevents LLVM from erasing things like /dev/null, any block 344 // special file, or other things that aren't "regular" files. 345 if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode)) 346 return make_error_code(errc::operation_not_permitted); 347 348 if (::remove(p.begin()) == -1) { 349 if (errno != ENOENT || !IgnoreNonExisting) 350 return std::error_code(errno, std::generic_category()); 351 } 352 353 return std::error_code(); 354} 355 356static bool is_local_impl(struct STATVFS &Vfs) { 357#if defined(__linux__) 358#ifndef NFS_SUPER_MAGIC 359#define NFS_SUPER_MAGIC 0x6969 360#endif 361#ifndef SMB_SUPER_MAGIC 362#define SMB_SUPER_MAGIC 0x517B 363#endif 364#ifndef CIFS_MAGIC_NUMBER 365#define CIFS_MAGIC_NUMBER 0xFF534D42 366#endif 367 switch ((uint32_t)Vfs.f_type) { 368 case NFS_SUPER_MAGIC: 369 case SMB_SUPER_MAGIC: 370 case CIFS_MAGIC_NUMBER: 371 return false; 372 default: 373 return true; 374 } 375#else 376 return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL); 377#endif 378} 379 380std::error_code is_local(const Twine &Path, bool &Result) { 381 struct STATVFS Vfs; 382 if (::STATVFS(Path.str().c_str(), &Vfs)) 383 return std::error_code(errno, std::generic_category()); 384 385 Result = is_local_impl(Vfs); 386 return std::error_code(); 387} 388 389std::error_code is_local(int FD, bool &Result) { 390 struct STATVFS Vfs; 391 if (::FSTATVFS(FD, &Vfs)) 392 return std::error_code(errno, std::generic_category()); 393 394 Result = is_local_impl(Vfs); 395 return std::error_code(); 396} 397 398std::error_code rename(const Twine &from, const Twine &to) { 399 // Get arguments. 400 SmallString<128> from_storage; 401 SmallString<128> to_storage; 402 StringRef f = from.toNullTerminatedStringRef(from_storage); 403 StringRef t = to.toNullTerminatedStringRef(to_storage); 404 405 if (::rename(f.begin(), t.begin()) == -1) 406 return std::error_code(errno, std::generic_category()); 407 408 return std::error_code(); 409} 410 411std::error_code resize_file(int FD, uint64_t Size) { 412#if defined(HAVE_POSIX_FALLOCATE) 413 // If we have posix_fallocate use it. Unlike ftruncate it always allocates 414 // space, so we get an error if the disk is full. 415 if (int Err = ::posix_fallocate(FD, 0, Size)) 416 return std::error_code(Err, std::generic_category()); 417#else 418 // Use ftruncate as a fallback. It may or may not allocate space. At least on 419 // OS X with HFS+ it does. 420 if (::ftruncate(FD, Size) == -1) 421 return std::error_code(errno, std::generic_category()); 422#endif 423 424 return std::error_code(); 425} 426 427static int convertAccessMode(AccessMode Mode) { 428 switch (Mode) { 429 case AccessMode::Exist: 430 return F_OK; 431 case AccessMode::Write: 432 return W_OK; 433 case AccessMode::Execute: 434 return R_OK | X_OK; // scripts also need R_OK. 435 } 436 llvm_unreachable("invalid enum"); 437} 438 439std::error_code access(const Twine &Path, AccessMode Mode) { 440 SmallString<128> PathStorage; 441 StringRef P = Path.toNullTerminatedStringRef(PathStorage); 442 443 if (::access(P.begin(), convertAccessMode(Mode)) == -1) 444 return std::error_code(errno, std::generic_category()); 445 446 if (Mode == AccessMode::Execute) { 447 // Don't say that directories are executable. 448 struct stat buf; 449 if (0 != stat(P.begin(), &buf)) 450 return errc::permission_denied; 451 if (!S_ISREG(buf.st_mode)) 452 return errc::permission_denied; 453 } 454 455 return std::error_code(); 456} 457 458bool can_execute(const Twine &Path) { 459 return !access(Path, AccessMode::Execute); 460} 461 462bool equivalent(file_status A, file_status B) { 463 assert(status_known(A) && status_known(B)); 464 return A.fs_st_dev == B.fs_st_dev && 465 A.fs_st_ino == B.fs_st_ino; 466} 467 468std::error_code equivalent(const Twine &A, const Twine &B, bool &result) { 469 file_status fsA, fsB; 470 if (std::error_code ec = status(A, fsA)) 471 return ec; 472 if (std::error_code ec = status(B, fsB)) 473 return ec; 474 result = equivalent(fsA, fsB); 475 return std::error_code(); 476} 477 478static std::error_code fillStatus(int StatRet, const struct stat &Status, 479 file_status &Result) { 480 if (StatRet != 0) { 481 std::error_code ec(errno, std::generic_category()); 482 if (ec == errc::no_such_file_or_directory) 483 Result = file_status(file_type::file_not_found); 484 else 485 Result = file_status(file_type::status_error); 486 return ec; 487 } 488 489 file_type Type = file_type::type_unknown; 490 491 if (S_ISDIR(Status.st_mode)) 492 Type = file_type::directory_file; 493 else if (S_ISREG(Status.st_mode)) 494 Type = file_type::regular_file; 495 else if (S_ISBLK(Status.st_mode)) 496 Type = file_type::block_file; 497 else if (S_ISCHR(Status.st_mode)) 498 Type = file_type::character_file; 499 else if (S_ISFIFO(Status.st_mode)) 500 Type = file_type::fifo_file; 501 else if (S_ISSOCK(Status.st_mode)) 502 Type = file_type::socket_file; 503 504 perms Perms = static_cast<perms>(Status.st_mode); 505 Result = 506 file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_atime, 507 Status.st_mtime, Status.st_uid, Status.st_gid, 508 Status.st_size); 509 510 return std::error_code(); 511} 512 513std::error_code status(const Twine &Path, file_status &Result) { 514 SmallString<128> PathStorage; 515 StringRef P = Path.toNullTerminatedStringRef(PathStorage); 516 517 struct stat Status; 518 int StatRet = ::stat(P.begin(), &Status); 519 return fillStatus(StatRet, Status, Result); 520} 521 522std::error_code status(int FD, file_status &Result) { 523 struct stat Status; 524 int StatRet = ::fstat(FD, &Status); 525 return fillStatus(StatRet, Status, Result); 526} 527 528std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) { 529#if defined(HAVE_FUTIMENS) 530 timespec Times[2]; 531 Times[0] = Times[1] = sys::toTimeSpec(Time); 532 if (::futimens(FD, Times)) 533 return std::error_code(errno, std::generic_category()); 534 return std::error_code(); 535#elif defined(HAVE_FUTIMES) 536 timeval Times[2]; 537 Times[0] = Times[1] = sys::toTimeVal( 538 std::chrono::time_point_cast<std::chrono::microseconds>(Time)); 539 if (::futimes(FD, Times)) 540 return std::error_code(errno, std::generic_category()); 541 return std::error_code(); 542#else 543#warning Missing futimes() and futimens() 544 return make_error_code(errc::function_not_supported); 545#endif 546} 547 548std::error_code mapped_file_region::init(int FD, uint64_t Offset, 549 mapmode Mode) { 550 assert(Size != 0); 551 552 int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE; 553 int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE); 554#if defined(__APPLE__) 555 //---------------------------------------------------------------------- 556 // Newer versions of MacOSX have a flag that will allow us to read from 557 // binaries whose code signature is invalid without crashing by using 558 // the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media 559 // is mapped we can avoid crashing and return zeroes to any pages we try 560 // to read if the media becomes unavailable by using the 561 // MAP_RESILIENT_MEDIA flag. These flags are only usable when mapping 562 // with PROT_READ, so take care not to specify them otherwise. 563 //---------------------------------------------------------------------- 564 if (Mode == readonly) { 565#if defined(MAP_RESILIENT_CODESIGN) 566 flags |= MAP_RESILIENT_CODESIGN; 567#endif 568#if defined(MAP_RESILIENT_MEDIA) 569 flags |= MAP_RESILIENT_MEDIA; 570#endif 571 } 572#endif // #if defined (__APPLE__) 573 574 Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset); 575 if (Mapping == MAP_FAILED) 576 return std::error_code(errno, std::generic_category()); 577 return std::error_code(); 578} 579 580mapped_file_region::mapped_file_region(int fd, mapmode mode, uint64_t length, 581 uint64_t offset, std::error_code &ec) 582 : Size(length), Mapping() { 583 // Make sure that the requested size fits within SIZE_T. 584 if (length > std::numeric_limits<size_t>::max()) { 585 ec = make_error_code(errc::invalid_argument); 586 return; 587 } 588 589 ec = init(fd, offset, mode); 590 if (ec) 591 Mapping = nullptr; 592} 593 594mapped_file_region::~mapped_file_region() { 595 if (Mapping) 596 ::munmap(Mapping, Size); 597} 598 599uint64_t mapped_file_region::size() const { 600 assert(Mapping && "Mapping failed but used anyway!"); 601 return Size; 602} 603 604char *mapped_file_region::data() const { 605 assert(Mapping && "Mapping failed but used anyway!"); 606 return reinterpret_cast<char*>(Mapping); 607} 608 609const char *mapped_file_region::const_data() const { 610 assert(Mapping && "Mapping failed but used anyway!"); 611 return reinterpret_cast<const char*>(Mapping); 612} 613 614int mapped_file_region::alignment() { 615 return Process::getPageSize(); 616} 617 618std::error_code detail::directory_iterator_construct(detail::DirIterState &it, 619 StringRef path){ 620 SmallString<128> path_null(path); 621 DIR *directory = ::opendir(path_null.c_str()); 622 if (!directory) 623 return std::error_code(errno, std::generic_category()); 624 625 it.IterationHandle = reinterpret_cast<intptr_t>(directory); 626 // Add something for replace_filename to replace. 627 path::append(path_null, "."); 628 it.CurrentEntry = directory_entry(path_null.str()); 629 return directory_iterator_increment(it); 630} 631 632std::error_code detail::directory_iterator_destruct(detail::DirIterState &it) { 633 if (it.IterationHandle) 634 ::closedir(reinterpret_cast<DIR *>(it.IterationHandle)); 635 it.IterationHandle = 0; 636 it.CurrentEntry = directory_entry(); 637 return std::error_code(); 638} 639 640std::error_code detail::directory_iterator_increment(detail::DirIterState &it) { 641 errno = 0; 642 dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle)); 643 if (cur_dir == nullptr && errno != 0) { 644 return std::error_code(errno, std::generic_category()); 645 } else if (cur_dir != nullptr) { 646 StringRef name(cur_dir->d_name, NAMLEN(cur_dir)); 647 if ((name.size() == 1 && name[0] == '.') || 648 (name.size() == 2 && name[0] == '.' && name[1] == '.')) 649 return directory_iterator_increment(it); 650 it.CurrentEntry.replace_filename(name); 651 } else 652 return directory_iterator_destruct(it); 653 654 return std::error_code(); 655} 656 657#if !defined(F_GETPATH) 658static bool hasProcSelfFD() { 659 // If we have a /proc filesystem mounted, we can quickly establish the 660 // real name of the file with readlink 661 static const bool Result = (::access("/proc/self/fd", R_OK) == 0); 662 return Result; 663} 664#endif 665 666std::error_code openFileForRead(const Twine &Name, int &ResultFD, 667 SmallVectorImpl<char> *RealPath) { 668 SmallString<128> Storage; 669 StringRef P = Name.toNullTerminatedStringRef(Storage); 670 int OpenFlags = O_RDONLY; 671#ifdef O_CLOEXEC 672 OpenFlags |= O_CLOEXEC; 673#endif 674 while ((ResultFD = open(P.begin(), OpenFlags)) < 0) { 675 if (errno != EINTR) 676 return std::error_code(errno, std::generic_category()); 677 } 678#ifndef O_CLOEXEC 679 int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC); 680 (void)r; 681 assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed"); 682#endif 683 // Attempt to get the real name of the file, if the user asked 684 if(!RealPath) 685 return std::error_code(); 686 RealPath->clear(); 687#if defined(F_GETPATH) 688 // When F_GETPATH is availble, it is the quickest way to get 689 // the real path name. 690 char Buffer[MAXPATHLEN]; 691 if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1) 692 RealPath->append(Buffer, Buffer + strlen(Buffer)); 693#else 694 char Buffer[PATH_MAX]; 695 if (hasProcSelfFD()) { 696 char ProcPath[64]; 697 snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD); 698 ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer)); 699 if (CharCount > 0) 700 RealPath->append(Buffer, Buffer + CharCount); 701 } else { 702 // Use ::realpath to get the real path name 703 if (::realpath(P.begin(), Buffer) != nullptr) 704 RealPath->append(Buffer, Buffer + strlen(Buffer)); 705 } 706#endif 707 return std::error_code(); 708} 709 710std::error_code openFileForWrite(const Twine &Name, int &ResultFD, 711 sys::fs::OpenFlags Flags, unsigned Mode) { 712 // Verify that we don't have both "append" and "excl". 713 assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) && 714 "Cannot specify both 'excl' and 'append' file creation flags!"); 715 716 int OpenFlags = O_CREAT; 717 718#ifdef O_CLOEXEC 719 OpenFlags |= O_CLOEXEC; 720#endif 721 722 if (Flags & F_RW) 723 OpenFlags |= O_RDWR; 724 else 725 OpenFlags |= O_WRONLY; 726 727 if (Flags & F_Append) 728 OpenFlags |= O_APPEND; 729 else 730 OpenFlags |= O_TRUNC; 731 732 if (Flags & F_Excl) 733 OpenFlags |= O_EXCL; 734 735 SmallString<128> Storage; 736 StringRef P = Name.toNullTerminatedStringRef(Storage); 737 while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) { 738 if (errno != EINTR) 739 return std::error_code(errno, std::generic_category()); 740 } 741#ifndef O_CLOEXEC 742 int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC); 743 (void)r; 744 assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed"); 745#endif 746 return std::error_code(); 747} 748 749std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) { 750 if (FD < 0) 751 return make_error_code(errc::bad_file_descriptor); 752 753#if defined(F_GETPATH) 754 // When F_GETPATH is availble, it is the quickest way to get 755 // the path from a file descriptor. 756 ResultPath.reserve(MAXPATHLEN); 757 if (::fcntl(FD, F_GETPATH, ResultPath.begin()) == -1) 758 return std::error_code(errno, std::generic_category()); 759 760 ResultPath.set_size(strlen(ResultPath.begin())); 761#else 762 // If we have a /proc filesystem mounted, we can quickly establish the 763 // real name of the file with readlink. Otherwise, we don't know how to 764 // get the filename from a file descriptor. Give up. 765 if (!fs::hasProcSelfFD()) 766 return make_error_code(errc::function_not_supported); 767 768 ResultPath.reserve(PATH_MAX); 769 char ProcPath[64]; 770 snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", FD); 771 ssize_t CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity()); 772 if (CharCount < 0) 773 return std::error_code(errno, std::generic_category()); 774 775 // Was the filename truncated? 776 if (static_cast<size_t>(CharCount) == ResultPath.capacity()) { 777 // Use lstat to get the size of the filename 778 struct stat sb; 779 if (::lstat(ProcPath, &sb) < 0) 780 return std::error_code(errno, std::generic_category()); 781 782 ResultPath.reserve(sb.st_size + 1); 783 CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity()); 784 if (CharCount < 0) 785 return std::error_code(errno, std::generic_category()); 786 787 // Test for race condition: did the link size change? 788 if (CharCount > sb.st_size) 789 return std::error_code(ENAMETOOLONG, std::generic_category()); 790 } 791 ResultPath.set_size(static_cast<size_t>(CharCount)); 792#endif 793 return std::error_code(); 794} 795 796} // end namespace fs 797 798namespace path { 799 800bool home_directory(SmallVectorImpl<char> &result) { 801 if (char *RequestedDir = getenv("HOME")) { 802 result.clear(); 803 result.append(RequestedDir, RequestedDir + strlen(RequestedDir)); 804 return true; 805 } 806 807 return false; 808} 809 810static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) { 811 #if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR) 812 // On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR. 813 // macros defined in <unistd.h> on darwin >= 9 814 int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR 815 : _CS_DARWIN_USER_CACHE_DIR; 816 size_t ConfLen = confstr(ConfName, nullptr, 0); 817 if (ConfLen > 0) { 818 do { 819 Result.resize(ConfLen); 820 ConfLen = confstr(ConfName, Result.data(), Result.size()); 821 } while (ConfLen > 0 && ConfLen != Result.size()); 822 823 if (ConfLen > 0) { 824 assert(Result.back() == 0); 825 Result.pop_back(); 826 return true; 827 } 828 829 Result.clear(); 830 } 831 #endif 832 return false; 833} 834 835static bool getUserCacheDir(SmallVectorImpl<char> &Result) { 836 // First try using XDG_CACHE_HOME env variable, 837 // as specified in XDG Base Directory Specification at 838 // http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html 839 if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) { 840 Result.clear(); 841 Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir)); 842 return true; 843 } 844 845 // Try Darwin configuration query 846 if (getDarwinConfDir(false, Result)) 847 return true; 848 849 // Use "$HOME/.cache" if $HOME is available 850 if (home_directory(Result)) { 851 append(Result, ".cache"); 852 return true; 853 } 854 855 return false; 856} 857 858static const char *getEnvTempDir() { 859 // Check whether the temporary directory is specified by an environment 860 // variable. 861 const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"}; 862 for (const char *Env : EnvironmentVariables) { 863 if (const char *Dir = std::getenv(Env)) 864 return Dir; 865 } 866 867 return nullptr; 868} 869 870static const char *getDefaultTempDir(bool ErasedOnReboot) { 871#ifdef P_tmpdir 872 if ((bool)P_tmpdir) 873 return P_tmpdir; 874#endif 875 876 if (ErasedOnReboot) 877 return "/tmp"; 878 return "/var/tmp"; 879} 880 881void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) { 882 Result.clear(); 883 884 if (ErasedOnReboot) { 885 // There is no env variable for the cache directory. 886 if (const char *RequestedDir = getEnvTempDir()) { 887 Result.append(RequestedDir, RequestedDir + strlen(RequestedDir)); 888 return; 889 } 890 } 891 892 if (getDarwinConfDir(ErasedOnReboot, Result)) 893 return; 894 895 const char *RequestedDir = getDefaultTempDir(ErasedOnReboot); 896 Result.append(RequestedDir, RequestedDir + strlen(RequestedDir)); 897} 898 899} // end namespace path 900 901} // end namespace sys 902} // end namespace llvm 903