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  1. //===- llvm/Support/FileSystem.h - File System OS Concept -------*- 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 declares the llvm::sys::fs namespace. It is designed after
  10. // TR2/boost filesystem (v3), but modified to remove exception handling and the
  11. // path class.
  12. //
  13. // All functions return an error_code and their actual work via the last out
  14. // argument. The out argument is defined if and only if errc::success is
  15. // returned. A function may return any error code in the generic or system
  16. // category. However, they shall be equivalent to any error conditions listed
  17. // in each functions respective documentation if the condition applies. [ note:
  18. // this does not guarantee that error_code will be in the set of explicitly
  19. // listed codes, but it does guarantee that if any of the explicitly listed
  20. // errors occur, the correct error_code will be used ]. All functions may
  21. // return errc::not_enough_memory if there is not enough memory to complete the
  22. // operation.
  23. //
  24. //===----------------------------------------------------------------------===//
  25.  
  26. #ifndef LLVM_SUPPORT_FILESYSTEM_H
  27. #define LLVM_SUPPORT_FILESYSTEM_H
  28.  
  29. #include "llvm/ADT/SmallString.h"
  30. #include "llvm/ADT/StringRef.h"
  31. #include "llvm/ADT/Twine.h"
  32. #include "llvm/Config/llvm-config.h"
  33. #include "llvm/Support/Chrono.h"
  34. #include "llvm/Support/Error.h"
  35. #include "llvm/Support/ErrorHandling.h"
  36. #include "llvm/Support/ErrorOr.h"
  37. #include "llvm/Support/FileSystem/UniqueID.h"
  38. #include "llvm/Support/MD5.h"
  39. #include <cassert>
  40. #include <cstdint>
  41. #include <ctime>
  42. #include <memory>
  43. #include <stack>
  44. #include <string>
  45. #include <system_error>
  46. #include <vector>
  47.  
  48. #ifdef HAVE_SYS_STAT_H
  49. #include <sys/stat.h>
  50. #endif
  51.  
  52. namespace llvm {
  53. namespace sys {
  54. namespace fs {
  55.  
  56. #if defined(_WIN32)
  57. // A Win32 HANDLE is a typedef of void*
  58. using file_t = void *;
  59. #else
  60. using file_t = int;
  61. #endif
  62.  
  63. extern const file_t kInvalidFile;
  64.  
  65. /// An enumeration for the file system's view of the type.
  66. enum class file_type {
  67.   status_error,
  68.   file_not_found,
  69.   regular_file,
  70.   directory_file,
  71.   symlink_file,
  72.   block_file,
  73.   character_file,
  74.   fifo_file,
  75.   socket_file,
  76.   type_unknown
  77. };
  78.  
  79. /// space_info - Self explanatory.
  80. struct space_info {
  81.   uint64_t capacity;
  82.   uint64_t free;
  83.   uint64_t available;
  84. };
  85.  
  86. enum perms {
  87.   no_perms = 0,
  88.   owner_read = 0400,
  89.   owner_write = 0200,
  90.   owner_exe = 0100,
  91.   owner_all = owner_read | owner_write | owner_exe,
  92.   group_read = 040,
  93.   group_write = 020,
  94.   group_exe = 010,
  95.   group_all = group_read | group_write | group_exe,
  96.   others_read = 04,
  97.   others_write = 02,
  98.   others_exe = 01,
  99.   others_all = others_read | others_write | others_exe,
  100.   all_read = owner_read | group_read | others_read,
  101.   all_write = owner_write | group_write | others_write,
  102.   all_exe = owner_exe | group_exe | others_exe,
  103.   all_all = owner_all | group_all | others_all,
  104.   set_uid_on_exe = 04000,
  105.   set_gid_on_exe = 02000,
  106.   sticky_bit = 01000,
  107.   all_perms = all_all | set_uid_on_exe | set_gid_on_exe | sticky_bit,
  108.   perms_not_known = 0xFFFF
  109. };
  110.  
  111. // Helper functions so that you can use & and | to manipulate perms bits:
  112. inline perms operator|(perms l, perms r) {
  113.   return static_cast<perms>(static_cast<unsigned short>(l) |
  114.                             static_cast<unsigned short>(r));
  115. }
  116. inline perms operator&(perms l, perms r) {
  117.   return static_cast<perms>(static_cast<unsigned short>(l) &
  118.                             static_cast<unsigned short>(r));
  119. }
  120. inline perms &operator|=(perms &l, perms r) {
  121.   l = l | r;
  122.   return l;
  123. }
  124. inline perms &operator&=(perms &l, perms r) {
  125.   l = l & r;
  126.   return l;
  127. }
  128. inline perms operator~(perms x) {
  129.   // Avoid UB by explicitly truncating the (unsigned) ~ result.
  130.   return static_cast<perms>(
  131.       static_cast<unsigned short>(~static_cast<unsigned short>(x)));
  132. }
  133.  
  134. /// Represents the result of a call to directory_iterator::status(). This is a
  135. /// subset of the information returned by a regular sys::fs::status() call, and
  136. /// represents the information provided by Windows FileFirstFile/FindNextFile.
  137. class basic_file_status {
  138. protected:
  139.   #if defined(LLVM_ON_UNIX)
  140.   time_t fs_st_atime = 0;
  141.   time_t fs_st_mtime = 0;
  142.   uint32_t fs_st_atime_nsec = 0;
  143.   uint32_t fs_st_mtime_nsec = 0;
  144.   uid_t fs_st_uid = 0;
  145.   gid_t fs_st_gid = 0;
  146.   off_t fs_st_size = 0;
  147.   #elif defined (_WIN32)
  148.   uint32_t LastAccessedTimeHigh = 0;
  149.   uint32_t LastAccessedTimeLow = 0;
  150.   uint32_t LastWriteTimeHigh = 0;
  151.   uint32_t LastWriteTimeLow = 0;
  152.   uint32_t FileSizeHigh = 0;
  153.   uint32_t FileSizeLow = 0;
  154.   #endif
  155.   file_type Type = file_type::status_error;
  156.   perms Perms = perms_not_known;
  157.  
  158. public:
  159.   basic_file_status() = default;
  160.  
  161.   explicit basic_file_status(file_type Type) : Type(Type) {}
  162.  
  163.   #if defined(LLVM_ON_UNIX)
  164.   basic_file_status(file_type Type, perms Perms, time_t ATime,
  165.                     uint32_t ATimeNSec, time_t MTime, uint32_t MTimeNSec,
  166.                     uid_t UID, gid_t GID, off_t Size)
  167.       : fs_st_atime(ATime), fs_st_mtime(MTime),
  168.         fs_st_atime_nsec(ATimeNSec), fs_st_mtime_nsec(MTimeNSec),
  169.         fs_st_uid(UID), fs_st_gid(GID),
  170.         fs_st_size(Size), Type(Type), Perms(Perms) {}
  171. #elif defined(_WIN32)
  172.   basic_file_status(file_type Type, perms Perms, uint32_t LastAccessTimeHigh,
  173.                     uint32_t LastAccessTimeLow, uint32_t LastWriteTimeHigh,
  174.                     uint32_t LastWriteTimeLow, uint32_t FileSizeHigh,
  175.                     uint32_t FileSizeLow)
  176.       : LastAccessedTimeHigh(LastAccessTimeHigh),
  177.         LastAccessedTimeLow(LastAccessTimeLow),
  178.         LastWriteTimeHigh(LastWriteTimeHigh),
  179.         LastWriteTimeLow(LastWriteTimeLow), FileSizeHigh(FileSizeHigh),
  180.         FileSizeLow(FileSizeLow), Type(Type), Perms(Perms) {}
  181.   #endif
  182.  
  183.   // getters
  184.   file_type type() const { return Type; }
  185.   perms permissions() const { return Perms; }
  186.  
  187.   /// The file access time as reported from the underlying file system.
  188.   ///
  189.   /// Also see comments on \c getLastModificationTime() related to the precision
  190.   /// of the returned value.
  191.   TimePoint<> getLastAccessedTime() const;
  192.  
  193.   /// The file modification time as reported from the underlying file system.
  194.   ///
  195.   /// The returned value allows for nanosecond precision but the actual
  196.   /// resolution is an implementation detail of the underlying file system.
  197.   /// There is no guarantee for what kind of resolution you can expect, the
  198.   /// resolution can differ across platforms and even across mountpoints on the
  199.   /// same machine.
  200.   TimePoint<> getLastModificationTime() const;
  201.  
  202.   #if defined(LLVM_ON_UNIX)
  203.   uint32_t getUser() const { return fs_st_uid; }
  204.   uint32_t getGroup() const { return fs_st_gid; }
  205.   uint64_t getSize() const { return fs_st_size; }
  206.   #elif defined (_WIN32)
  207.   uint32_t getUser() const {
  208.     return 9999; // Not applicable to Windows, so...
  209.   }
  210.  
  211.   uint32_t getGroup() const {
  212.     return 9999; // Not applicable to Windows, so...
  213.   }
  214.  
  215.   uint64_t getSize() const {
  216.     return (uint64_t(FileSizeHigh) << 32) + FileSizeLow;
  217.   }
  218.   #endif
  219.  
  220.   // setters
  221.   void type(file_type v) { Type = v; }
  222.   void permissions(perms p) { Perms = p; }
  223. };
  224.  
  225. /// Represents the result of a call to sys::fs::status().
  226. class file_status : public basic_file_status {
  227.   friend bool equivalent(file_status A, file_status B);
  228.  
  229.   #if defined(LLVM_ON_UNIX)
  230.   dev_t fs_st_dev = 0;
  231.   nlink_t fs_st_nlinks = 0;
  232.   ino_t fs_st_ino = 0;
  233.   #elif defined (_WIN32)
  234.   uint32_t NumLinks = 0;
  235.   uint32_t VolumeSerialNumber = 0;
  236.   uint32_t FileIndexHigh = 0;
  237.   uint32_t FileIndexLow = 0;
  238.   #endif
  239.  
  240. public:
  241.   file_status() = default;
  242.  
  243.   explicit file_status(file_type Type) : basic_file_status(Type) {}
  244.  
  245.   #if defined(LLVM_ON_UNIX)
  246.   file_status(file_type Type, perms Perms, dev_t Dev, nlink_t Links, ino_t Ino,
  247.               time_t ATime, uint32_t ATimeNSec,
  248.               time_t MTime, uint32_t MTimeNSec,
  249.               uid_t UID, gid_t GID, off_t Size)
  250.       : basic_file_status(Type, Perms, ATime, ATimeNSec, MTime, MTimeNSec,
  251.                           UID, GID, Size),
  252.         fs_st_dev(Dev), fs_st_nlinks(Links), fs_st_ino(Ino) {}
  253.   #elif defined(_WIN32)
  254.   file_status(file_type Type, perms Perms, uint32_t LinkCount,
  255.               uint32_t LastAccessTimeHigh, uint32_t LastAccessTimeLow,
  256.               uint32_t LastWriteTimeHigh, uint32_t LastWriteTimeLow,
  257.               uint32_t VolumeSerialNumber, uint32_t FileSizeHigh,
  258.               uint32_t FileSizeLow, uint32_t FileIndexHigh,
  259.               uint32_t FileIndexLow)
  260.       : basic_file_status(Type, Perms, LastAccessTimeHigh, LastAccessTimeLow,
  261.                           LastWriteTimeHigh, LastWriteTimeLow, FileSizeHigh,
  262.                           FileSizeLow),
  263.         NumLinks(LinkCount), VolumeSerialNumber(VolumeSerialNumber),
  264.         FileIndexHigh(FileIndexHigh), FileIndexLow(FileIndexLow) {}
  265.   #endif
  266.  
  267.   UniqueID getUniqueID() const;
  268.   uint32_t getLinkCount() const;
  269. };
  270.  
  271. /// @}
  272. /// @name Physical Operators
  273. /// @{
  274.  
  275. /// Make \a path an absolute path.
  276. ///
  277. /// Makes \a path absolute using the \a current_directory if it is not already.
  278. /// An empty \a path will result in the \a current_directory.
  279. ///
  280. /// /absolute/path   => /absolute/path
  281. /// relative/../path => <current-directory>/relative/../path
  282. ///
  283. /// @param path A path that is modified to be an absolute path.
  284. void make_absolute(const Twine &current_directory, SmallVectorImpl<char> &path);
  285.  
  286. /// Make \a path an absolute path.
  287. ///
  288. /// Makes \a path absolute using the current directory if it is not already. An
  289. /// empty \a path will result in the current directory.
  290. ///
  291. /// /absolute/path   => /absolute/path
  292. /// relative/../path => <current-directory>/relative/../path
  293. ///
  294. /// @param path A path that is modified to be an absolute path.
  295. /// @returns errc::success if \a path has been made absolute, otherwise a
  296. ///          platform-specific error_code.
  297. std::error_code make_absolute(SmallVectorImpl<char> &path);
  298.  
  299. /// Create all the non-existent directories in path.
  300. ///
  301. /// @param path Directories to create.
  302. /// @returns errc::success if is_directory(path), otherwise a platform
  303. ///          specific error_code. If IgnoreExisting is false, also returns
  304. ///          error if the directory already existed.
  305. std::error_code create_directories(const Twine &path,
  306.                                    bool IgnoreExisting = true,
  307.                                    perms Perms = owner_all | group_all);
  308.  
  309. /// Create the directory in path.
  310. ///
  311. /// @param path Directory to create.
  312. /// @returns errc::success if is_directory(path), otherwise a platform
  313. ///          specific error_code. If IgnoreExisting is false, also returns
  314. ///          error if the directory already existed.
  315. std::error_code create_directory(const Twine &path, bool IgnoreExisting = true,
  316.                                  perms Perms = owner_all | group_all);
  317.  
  318. /// Create a link from \a from to \a to.
  319. ///
  320. /// The link may be a soft or a hard link, depending on the platform. The caller
  321. /// may not assume which one. Currently on windows it creates a hard link since
  322. /// soft links require extra privileges. On unix, it creates a soft link since
  323. /// hard links don't work on SMB file systems.
  324. ///
  325. /// @param to The path to hard link to.
  326. /// @param from The path to hard link from. This is created.
  327. /// @returns errc::success if the link was created, otherwise a platform
  328. /// specific error_code.
  329. std::error_code create_link(const Twine &to, const Twine &from);
  330.  
  331. /// Create a hard link from \a from to \a to, or return an error.
  332. ///
  333. /// @param to The path to hard link to.
  334. /// @param from The path to hard link from. This is created.
  335. /// @returns errc::success if the link was created, otherwise a platform
  336. /// specific error_code.
  337. std::error_code create_hard_link(const Twine &to, const Twine &from);
  338.  
  339. /// Collapse all . and .. patterns, resolve all symlinks, and optionally
  340. ///        expand ~ expressions to the user's home directory.
  341. ///
  342. /// @param path The path to resolve.
  343. /// @param output The location to store the resolved path.
  344. /// @param expand_tilde If true, resolves ~ expressions to the user's home
  345. ///                     directory.
  346. std::error_code real_path(const Twine &path, SmallVectorImpl<char> &output,
  347.                           bool expand_tilde = false);
  348.  
  349. /// Expands ~ expressions to the user's home directory. On Unix ~user
  350. /// directories are resolved as well.
  351. ///
  352. /// @param path The path to resolve.
  353. void expand_tilde(const Twine &path, SmallVectorImpl<char> &output);
  354.  
  355. /// Get the current path.
  356. ///
  357. /// @param result Holds the current path on return.
  358. /// @returns errc::success if the current path has been stored in result,
  359. ///          otherwise a platform-specific error_code.
  360. std::error_code current_path(SmallVectorImpl<char> &result);
  361.  
  362. /// Set the current path.
  363. ///
  364. /// @param path The path to set.
  365. /// @returns errc::success if the current path was successfully set,
  366. ///          otherwise a platform-specific error_code.
  367. std::error_code set_current_path(const Twine &path);
  368.  
  369. /// Remove path. Equivalent to POSIX remove().
  370. ///
  371. /// @param path Input path.
  372. /// @returns errc::success if path has been removed or didn't exist, otherwise a
  373. ///          platform-specific error code. If IgnoreNonExisting is false, also
  374. ///          returns error if the file didn't exist.
  375. std::error_code remove(const Twine &path, bool IgnoreNonExisting = true);
  376.  
  377. /// Recursively delete a directory.
  378. ///
  379. /// @param path Input path.
  380. /// @returns errc::success if path has been removed or didn't exist, otherwise a
  381. ///          platform-specific error code.
  382. std::error_code remove_directories(const Twine &path, bool IgnoreErrors = true);
  383.  
  384. /// Rename \a from to \a to.
  385. ///
  386. /// Files are renamed as if by POSIX rename(), except that on Windows there may
  387. /// be a short interval of time during which the destination file does not
  388. /// exist.
  389. ///
  390. /// @param from The path to rename from.
  391. /// @param to The path to rename to. This is created.
  392. std::error_code rename(const Twine &from, const Twine &to);
  393.  
  394. /// Copy the contents of \a From to \a To.
  395. ///
  396. /// @param From The path to copy from.
  397. /// @param To The path to copy to. This is created.
  398. std::error_code copy_file(const Twine &From, const Twine &To);
  399.  
  400. /// Copy the contents of \a From to \a To.
  401. ///
  402. /// @param From The path to copy from.
  403. /// @param ToFD The open file descriptor of the destination file.
  404. std::error_code copy_file(const Twine &From, int ToFD);
  405.  
  406. /// Resize path to size. File is resized as if by POSIX truncate().
  407. ///
  408. /// @param FD Input file descriptor.
  409. /// @param Size Size to resize to.
  410. /// @returns errc::success if \a path has been resized to \a size, otherwise a
  411. ///          platform-specific error_code.
  412. std::error_code resize_file(int FD, uint64_t Size);
  413.  
  414. /// Resize \p FD to \p Size before mapping \a mapped_file_region::readwrite. On
  415. /// non-Windows, this calls \a resize_file(). On Windows, this is a no-op,
  416. /// since the subsequent mapping (via \c CreateFileMapping) automatically
  417. /// extends the file.
  418. inline std::error_code resize_file_before_mapping_readwrite(int FD,
  419.                                                             uint64_t Size) {
  420. #ifdef _WIN32
  421.   (void)FD;
  422.   (void)Size;
  423.   return std::error_code();
  424. #else
  425.   return resize_file(FD, Size);
  426. #endif
  427. }
  428.  
  429. /// Compute an MD5 hash of a file's contents.
  430. ///
  431. /// @param FD Input file descriptor.
  432. /// @returns An MD5Result with the hash computed, if successful, otherwise a
  433. ///          std::error_code.
  434. ErrorOr<MD5::MD5Result> md5_contents(int FD);
  435.  
  436. /// Version of compute_md5 that doesn't require an open file descriptor.
  437. ErrorOr<MD5::MD5Result> md5_contents(const Twine &Path);
  438.  
  439. /// @}
  440. /// @name Physical Observers
  441. /// @{
  442.  
  443. /// Does file exist?
  444. ///
  445. /// @param status A basic_file_status previously returned from stat.
  446. /// @returns True if the file represented by status exists, false if it does
  447. ///          not.
  448. bool exists(const basic_file_status &status);
  449.  
  450. enum class AccessMode { Exist, Write, Execute };
  451.  
  452. /// Can the file be accessed?
  453. ///
  454. /// @param Path Input path.
  455. /// @returns errc::success if the path can be accessed, otherwise a
  456. ///          platform-specific error_code.
  457. std::error_code access(const Twine &Path, AccessMode Mode);
  458.  
  459. /// Does file exist?
  460. ///
  461. /// @param Path Input path.
  462. /// @returns True if it exists, false otherwise.
  463. inline bool exists(const Twine &Path) {
  464.   return !access(Path, AccessMode::Exist);
  465. }
  466.  
  467. /// Can we execute this file?
  468. ///
  469. /// @param Path Input path.
  470. /// @returns True if we can execute it, false otherwise.
  471. bool can_execute(const Twine &Path);
  472.  
  473. /// Can we write this file?
  474. ///
  475. /// @param Path Input path.
  476. /// @returns True if we can write to it, false otherwise.
  477. inline bool can_write(const Twine &Path) {
  478.   return !access(Path, AccessMode::Write);
  479. }
  480.  
  481. /// Do file_status's represent the same thing?
  482. ///
  483. /// @param A Input file_status.
  484. /// @param B Input file_status.
  485. ///
  486. /// assert(status_known(A) || status_known(B));
  487. ///
  488. /// @returns True if A and B both represent the same file system entity, false
  489. ///          otherwise.
  490. bool equivalent(file_status A, file_status B);
  491.  
  492. /// Do paths represent the same thing?
  493. ///
  494. /// assert(status_known(A) || status_known(B));
  495. ///
  496. /// @param A Input path A.
  497. /// @param B Input path B.
  498. /// @param result Set to true if stat(A) and stat(B) have the same device and
  499. ///               inode (or equivalent).
  500. /// @returns errc::success if result has been successfully set, otherwise a
  501. ///          platform-specific error_code.
  502. std::error_code equivalent(const Twine &A, const Twine &B, bool &result);
  503.  
  504. /// Simpler version of equivalent for clients that don't need to
  505. ///        differentiate between an error and false.
  506. inline bool equivalent(const Twine &A, const Twine &B) {
  507.   bool result;
  508.   return !equivalent(A, B, result) && result;
  509. }
  510.  
  511. /// Is the file mounted on a local filesystem?
  512. ///
  513. /// @param path Input path.
  514. /// @param result Set to true if \a path is on fixed media such as a hard disk,
  515. ///               false if it is not.
  516. /// @returns errc::success if result has been successfully set, otherwise a
  517. ///          platform specific error_code.
  518. std::error_code is_local(const Twine &path, bool &result);
  519.  
  520. /// Version of is_local accepting an open file descriptor.
  521. std::error_code is_local(int FD, bool &result);
  522.  
  523. /// Simpler version of is_local for clients that don't need to
  524. ///        differentiate between an error and false.
  525. inline bool is_local(const Twine &Path) {
  526.   bool Result;
  527.   return !is_local(Path, Result) && Result;
  528. }
  529.  
  530. /// Simpler version of is_local accepting an open file descriptor for
  531. ///        clients that don't need to differentiate between an error and false.
  532. inline bool is_local(int FD) {
  533.   bool Result;
  534.   return !is_local(FD, Result) && Result;
  535. }
  536.  
  537. /// Does status represent a directory?
  538. ///
  539. /// @param Path The path to get the type of.
  540. /// @param Follow For symbolic links, indicates whether to return the file type
  541. ///               of the link itself, or of the target.
  542. /// @returns A value from the file_type enumeration indicating the type of file.
  543. file_type get_file_type(const Twine &Path, bool Follow = true);
  544.  
  545. /// Does status represent a directory?
  546. ///
  547. /// @param status A basic_file_status previously returned from status.
  548. /// @returns status.type() == file_type::directory_file.
  549. bool is_directory(const basic_file_status &status);
  550.  
  551. /// Is path a directory?
  552. ///
  553. /// @param path Input path.
  554. /// @param result Set to true if \a path is a directory (after following
  555. ///               symlinks, false if it is not. Undefined otherwise.
  556. /// @returns errc::success if result has been successfully set, otherwise a
  557. ///          platform-specific error_code.
  558. std::error_code is_directory(const Twine &path, bool &result);
  559.  
  560. /// Simpler version of is_directory for clients that don't need to
  561. ///        differentiate between an error and false.
  562. inline bool is_directory(const Twine &Path) {
  563.   bool Result;
  564.   return !is_directory(Path, Result) && Result;
  565. }
  566.  
  567. /// Does status represent a regular file?
  568. ///
  569. /// @param status A basic_file_status previously returned from status.
  570. /// @returns status_known(status) && status.type() == file_type::regular_file.
  571. bool is_regular_file(const basic_file_status &status);
  572.  
  573. /// Is path a regular file?
  574. ///
  575. /// @param path Input path.
  576. /// @param result Set to true if \a path is a regular file (after following
  577. ///               symlinks), false if it is not. Undefined otherwise.
  578. /// @returns errc::success if result has been successfully set, otherwise a
  579. ///          platform-specific error_code.
  580. std::error_code is_regular_file(const Twine &path, bool &result);
  581.  
  582. /// Simpler version of is_regular_file for clients that don't need to
  583. ///        differentiate between an error and false.
  584. inline bool is_regular_file(const Twine &Path) {
  585.   bool Result;
  586.   if (is_regular_file(Path, Result))
  587.     return false;
  588.   return Result;
  589. }
  590.  
  591. /// Does status represent a symlink file?
  592. ///
  593. /// @param status A basic_file_status previously returned from status.
  594. /// @returns status_known(status) && status.type() == file_type::symlink_file.
  595. bool is_symlink_file(const basic_file_status &status);
  596.  
  597. /// Is path a symlink file?
  598. ///
  599. /// @param path Input path.
  600. /// @param result Set to true if \a path is a symlink file, false if it is not.
  601. ///               Undefined otherwise.
  602. /// @returns errc::success if result has been successfully set, otherwise a
  603. ///          platform-specific error_code.
  604. std::error_code is_symlink_file(const Twine &path, bool &result);
  605.  
  606. /// Simpler version of is_symlink_file for clients that don't need to
  607. ///        differentiate between an error and false.
  608. inline bool is_symlink_file(const Twine &Path) {
  609.   bool Result;
  610.   if (is_symlink_file(Path, Result))
  611.     return false;
  612.   return Result;
  613. }
  614.  
  615. /// Does this status represent something that exists but is not a
  616. ///        directory or regular file?
  617. ///
  618. /// @param status A basic_file_status previously returned from status.
  619. /// @returns exists(s) && !is_regular_file(s) && !is_directory(s)
  620. bool is_other(const basic_file_status &status);
  621.  
  622. /// Is path something that exists but is not a directory,
  623. ///        regular file, or symlink?
  624. ///
  625. /// @param path Input path.
  626. /// @param result Set to true if \a path exists, but is not a directory, regular
  627. ///               file, or a symlink, false if it does not. Undefined otherwise.
  628. /// @returns errc::success if result has been successfully set, otherwise a
  629. ///          platform-specific error_code.
  630. std::error_code is_other(const Twine &path, bool &result);
  631.  
  632. /// Get file status as if by POSIX stat().
  633. ///
  634. /// @param path Input path.
  635. /// @param result Set to the file status.
  636. /// @param follow When true, follows symlinks.  Otherwise, the symlink itself is
  637. ///               statted.
  638. /// @returns errc::success if result has been successfully set, otherwise a
  639. ///          platform-specific error_code.
  640. std::error_code status(const Twine &path, file_status &result,
  641.                        bool follow = true);
  642.  
  643. /// A version for when a file descriptor is already available.
  644. std::error_code status(int FD, file_status &Result);
  645.  
  646. #ifdef _WIN32
  647. /// A version for when a file descriptor is already available.
  648. std::error_code status(file_t FD, file_status &Result);
  649. #endif
  650.  
  651. /// Get file creation mode mask of the process.
  652. ///
  653. /// @returns Mask reported by umask(2)
  654. /// @note There is no umask on Windows. This function returns 0 always
  655. ///       on Windows. This function does not return an error_code because
  656. ///       umask(2) never fails. It is not thread safe.
  657. unsigned getUmask();
  658.  
  659. /// Set file permissions.
  660. ///
  661. /// @param Path File to set permissions on.
  662. /// @param Permissions New file permissions.
  663. /// @returns errc::success if the permissions were successfully set, otherwise
  664. ///          a platform-specific error_code.
  665. /// @note On Windows, all permissions except *_write are ignored. Using any of
  666. ///       owner_write, group_write, or all_write will make the file writable.
  667. ///       Otherwise, the file will be marked as read-only.
  668. std::error_code setPermissions(const Twine &Path, perms Permissions);
  669.  
  670. /// Vesion of setPermissions accepting a file descriptor.
  671. /// TODO Delete the path based overload once we implement the FD based overload
  672. /// on Windows.
  673. std::error_code setPermissions(int FD, perms Permissions);
  674.  
  675. /// Get file permissions.
  676. ///
  677. /// @param Path File to get permissions from.
  678. /// @returns the permissions if they were successfully retrieved, otherwise a
  679. ///          platform-specific error_code.
  680. /// @note On Windows, if the file does not have the FILE_ATTRIBUTE_READONLY
  681. ///       attribute, all_all will be returned. Otherwise, all_read | all_exe
  682. ///       will be returned.
  683. ErrorOr<perms> getPermissions(const Twine &Path);
  684.  
  685. /// Get file size.
  686. ///
  687. /// @param Path Input path.
  688. /// @param Result Set to the size of the file in \a Path.
  689. /// @returns errc::success if result has been successfully set, otherwise a
  690. ///          platform-specific error_code.
  691. inline std::error_code file_size(const Twine &Path, uint64_t &Result) {
  692.   file_status Status;
  693.   std::error_code EC = status(Path, Status);
  694.   if (EC)
  695.     return EC;
  696.   Result = Status.getSize();
  697.   return std::error_code();
  698. }
  699.  
  700. /// Set the file modification and access time.
  701. ///
  702. /// @returns errc::success if the file times were successfully set, otherwise a
  703. ///          platform-specific error_code or errc::function_not_supported on
  704. ///          platforms where the functionality isn't available.
  705. std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
  706.                                                  TimePoint<> ModificationTime);
  707.  
  708. /// Simpler version that sets both file modification and access time to the same
  709. /// time.
  710. inline std::error_code setLastAccessAndModificationTime(int FD,
  711.                                                         TimePoint<> Time) {
  712.   return setLastAccessAndModificationTime(FD, Time, Time);
  713. }
  714.  
  715. /// Is status available?
  716. ///
  717. /// @param s Input file status.
  718. /// @returns True if status() != status_error.
  719. bool status_known(const basic_file_status &s);
  720.  
  721. /// Is status available?
  722. ///
  723. /// @param path Input path.
  724. /// @param result Set to true if status() != status_error.
  725. /// @returns errc::success if result has been successfully set, otherwise a
  726. ///          platform-specific error_code.
  727. std::error_code status_known(const Twine &path, bool &result);
  728.  
  729. enum CreationDisposition : unsigned {
  730.   /// CD_CreateAlways - When opening a file:
  731.   ///   * If it already exists, truncate it.
  732.   ///   * If it does not already exist, create a new file.
  733.   CD_CreateAlways = 0,
  734.  
  735.   /// CD_CreateNew - When opening a file:
  736.   ///   * If it already exists, fail.
  737.   ///   * If it does not already exist, create a new file.
  738.   CD_CreateNew = 1,
  739.  
  740.   /// CD_OpenExisting - When opening a file:
  741.   ///   * If it already exists, open the file with the offset set to 0.
  742.   ///   * If it does not already exist, fail.
  743.   CD_OpenExisting = 2,
  744.  
  745.   /// CD_OpenAlways - When opening a file:
  746.   ///   * If it already exists, open the file with the offset set to 0.
  747.   ///   * If it does not already exist, create a new file.
  748.   CD_OpenAlways = 3,
  749. };
  750.  
  751. enum FileAccess : unsigned {
  752.   FA_Read = 1,
  753.   FA_Write = 2,
  754. };
  755.  
  756. enum OpenFlags : unsigned {
  757.   OF_None = 0,
  758.  
  759.   /// The file should be opened in text mode on platforms like z/OS that make
  760.   /// this distinction.
  761.   OF_Text = 1,
  762.  
  763.   /// The file should use a carriage linefeed '\r\n'. This flag should only be
  764.   /// used with OF_Text. Only makes a difference on Windows.
  765.   OF_CRLF = 2,
  766.  
  767.   /// The file should be opened in text mode and use a carriage linefeed '\r\n'.
  768.   /// This flag has the same functionality as OF_Text on z/OS but adds a
  769.   /// carriage linefeed on Windows.
  770.   OF_TextWithCRLF = OF_Text | OF_CRLF,
  771.  
  772.   /// The file should be opened in append mode.
  773.   OF_Append = 4,
  774.  
  775.   /// The returned handle can be used for deleting the file. Only makes a
  776.   /// difference on windows.
  777.   OF_Delete = 8,
  778.  
  779.   /// When a child process is launched, this file should remain open in the
  780.   /// child process.
  781.   OF_ChildInherit = 16,
  782.  
  783.   /// Force files Atime to be updated on access. Only makes a difference on
  784.   /// Windows.
  785.   OF_UpdateAtime = 32,
  786. };
  787.  
  788. /// Create a potentially unique file name but does not create it.
  789. ///
  790. /// Generates a unique path suitable for a temporary file but does not
  791. /// open or create the file. The name is based on \a Model with '%'
  792. /// replaced by a random char in [0-9a-f]. If \a MakeAbsolute is true
  793. /// then the system's temp directory is prepended first. If \a MakeAbsolute
  794. /// is false the current directory will be used instead.
  795. ///
  796. /// This function does not check if the file exists. If you want to be sure
  797. /// that the file does not yet exist, you should use use enough '%' characters
  798. /// in your model to ensure this. Each '%' gives 4-bits of entropy so you can
  799. /// use 32 of them to get 128 bits of entropy.
  800. ///
  801. /// Example: clang-%%-%%-%%-%%-%%.s => clang-a0-b1-c2-d3-e4.s
  802. ///
  803. /// @param Model Name to base unique path off of.
  804. /// @param ResultPath Set to the file's path.
  805. /// @param MakeAbsolute Whether to use the system temp directory.
  806. void createUniquePath(const Twine &Model, SmallVectorImpl<char> &ResultPath,
  807.                       bool MakeAbsolute);
  808.  
  809. /// Create a uniquely named file.
  810. ///
  811. /// Generates a unique path suitable for a temporary file and then opens it as a
  812. /// file. The name is based on \a Model with '%' replaced by a random char in
  813. /// [0-9a-f]. If \a Model is not an absolute path, the temporary file will be
  814. /// created in the current directory.
  815. ///
  816. /// Example: clang-%%-%%-%%-%%-%%.s => clang-a0-b1-c2-d3-e4.s
  817. ///
  818. /// This is an atomic operation. Either the file is created and opened, or the
  819. /// file system is left untouched.
  820. ///
  821. /// The intended use is for files that are to be kept, possibly after
  822. /// renaming them. For example, when running 'clang -c foo.o', the file can
  823. /// be first created as foo-abc123.o and then renamed.
  824. ///
  825. /// @param Model Name to base unique path off of.
  826. /// @param ResultFD Set to the opened file's file descriptor.
  827. /// @param ResultPath Set to the opened file's absolute path.
  828. /// @param Flags Set to the opened file's flags.
  829. /// @param Mode Set to the opened file's permissions.
  830. /// @returns errc::success if Result{FD,Path} have been successfully set,
  831. ///          otherwise a platform-specific error_code.
  832. std::error_code createUniqueFile(const Twine &Model, int &ResultFD,
  833.                                  SmallVectorImpl<char> &ResultPath,
  834.                                  OpenFlags Flags = OF_None,
  835.                                  unsigned Mode = all_read | all_write);
  836.  
  837. /// Simpler version for clients that don't want an open file. An empty
  838. /// file will still be created.
  839. std::error_code createUniqueFile(const Twine &Model,
  840.                                  SmallVectorImpl<char> &ResultPath,
  841.                                  unsigned Mode = all_read | all_write);
  842.  
  843. /// Represents a temporary file.
  844. ///
  845. /// The temporary file must be eventually discarded or given a final name and
  846. /// kept.
  847. ///
  848. /// The destructor doesn't implicitly discard because there is no way to
  849. /// properly handle errors in a destructor.
  850. class TempFile {
  851.   bool Done = false;
  852.   TempFile(StringRef Name, int FD);
  853.  
  854. public:
  855.   /// This creates a temporary file with createUniqueFile and schedules it for
  856.   /// deletion with sys::RemoveFileOnSignal.
  857.   static Expected<TempFile> create(const Twine &Model,
  858.                                    unsigned Mode = all_read | all_write,
  859.                                    OpenFlags ExtraFlags = OF_None);
  860.   TempFile(TempFile &&Other);
  861.   TempFile &operator=(TempFile &&Other);
  862.  
  863.   // Name of the temporary file.
  864.   std::string TmpName;
  865.  
  866.   // The open file descriptor.
  867.   int FD = -1;
  868.  
  869. #ifdef _WIN32
  870.   // Whether we need to manually remove the file on close.
  871.   bool RemoveOnClose = false;
  872. #endif
  873.  
  874.   // Keep this with the given name.
  875.   Error keep(const Twine &Name);
  876.  
  877.   // Keep this with the temporary name.
  878.   Error keep();
  879.  
  880.   // Delete the file.
  881.   Error discard();
  882.  
  883.   // This checks that keep or delete was called.
  884.   ~TempFile();
  885. };
  886.  
  887. /// Create a file in the system temporary directory.
  888. ///
  889. /// The filename is of the form prefix-random_chars.suffix. Since the directory
  890. /// is not know to the caller, Prefix and Suffix cannot have path separators.
  891. /// The files are created with mode 0600.
  892. ///
  893. /// This should be used for things like a temporary .s that is removed after
  894. /// running the assembler.
  895. std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
  896.                                     int &ResultFD,
  897.                                     SmallVectorImpl<char> &ResultPath,
  898.                                     OpenFlags Flags = OF_None);
  899.  
  900. /// Simpler version for clients that don't want an open file. An empty
  901. /// file will still be created.
  902. std::error_code createTemporaryFile(const Twine &Prefix, StringRef Suffix,
  903.                                     SmallVectorImpl<char> &ResultPath,
  904.                                     OpenFlags Flags = OF_None);
  905.  
  906. std::error_code createUniqueDirectory(const Twine &Prefix,
  907.                                       SmallVectorImpl<char> &ResultPath);
  908.  
  909. /// Get a unique name, not currently exisiting in the filesystem. Subject
  910. /// to race conditions, prefer to use createUniqueFile instead.
  911. ///
  912. /// Similar to createUniqueFile, but instead of creating a file only
  913. /// checks if it exists. This function is subject to race conditions, if you
  914. /// want to use the returned name to actually create a file, use
  915. /// createUniqueFile instead.
  916. std::error_code getPotentiallyUniqueFileName(const Twine &Model,
  917.                                              SmallVectorImpl<char> &ResultPath);
  918.  
  919. /// Get a unique temporary file name, not currently exisiting in the
  920. /// filesystem. Subject to race conditions, prefer to use createTemporaryFile
  921. /// instead.
  922. ///
  923. /// Similar to createTemporaryFile, but instead of creating a file only
  924. /// checks if it exists. This function is subject to race conditions, if you
  925. /// want to use the returned name to actually create a file, use
  926. /// createTemporaryFile instead.
  927. std::error_code
  928. getPotentiallyUniqueTempFileName(const Twine &Prefix, StringRef Suffix,
  929.                                  SmallVectorImpl<char> &ResultPath);
  930.  
  931. inline OpenFlags operator|(OpenFlags A, OpenFlags B) {
  932.   return OpenFlags(unsigned(A) | unsigned(B));
  933. }
  934.  
  935. inline OpenFlags &operator|=(OpenFlags &A, OpenFlags B) {
  936.   A = A | B;
  937.   return A;
  938. }
  939.  
  940. inline FileAccess operator|(FileAccess A, FileAccess B) {
  941.   return FileAccess(unsigned(A) | unsigned(B));
  942. }
  943.  
  944. inline FileAccess &operator|=(FileAccess &A, FileAccess B) {
  945.   A = A | B;
  946.   return A;
  947. }
  948.  
  949. /// @brief Opens a file with the specified creation disposition, access mode,
  950. /// and flags and returns a file descriptor.
  951. ///
  952. /// The caller is responsible for closing the file descriptor once they are
  953. /// finished with it.
  954. ///
  955. /// @param Name The path of the file to open, relative or absolute.
  956. /// @param ResultFD If the file could be opened successfully, its descriptor
  957. ///                 is stored in this location. Otherwise, this is set to -1.
  958. /// @param Disp Value specifying the existing-file behavior.
  959. /// @param Access Value specifying whether to open the file in read, write, or
  960. ///               read-write mode.
  961. /// @param Flags Additional flags.
  962. /// @param Mode The access permissions of the file, represented in octal.
  963. /// @returns errc::success if \a Name has been opened, otherwise a
  964. ///          platform-specific error_code.
  965. std::error_code openFile(const Twine &Name, int &ResultFD,
  966.                          CreationDisposition Disp, FileAccess Access,
  967.                          OpenFlags Flags, unsigned Mode = 0666);
  968.  
  969. /// @brief Opens a file with the specified creation disposition, access mode,
  970. /// and flags and returns a platform-specific file object.
  971. ///
  972. /// The caller is responsible for closing the file object once they are
  973. /// finished with it.
  974. ///
  975. /// @param Name The path of the file to open, relative or absolute.
  976. /// @param Disp Value specifying the existing-file behavior.
  977. /// @param Access Value specifying whether to open the file in read, write, or
  978. ///               read-write mode.
  979. /// @param Flags Additional flags.
  980. /// @param Mode The access permissions of the file, represented in octal.
  981. /// @returns errc::success if \a Name has been opened, otherwise a
  982. ///          platform-specific error_code.
  983. Expected<file_t> openNativeFile(const Twine &Name, CreationDisposition Disp,
  984.                                 FileAccess Access, OpenFlags Flags,
  985.                                 unsigned Mode = 0666);
  986.  
  987. /// Converts from a Posix file descriptor number to a native file handle.
  988. /// On Windows, this retreives the underlying handle. On non-Windows, this is a
  989. /// no-op.
  990. file_t convertFDToNativeFile(int FD);
  991.  
  992. #ifndef _WIN32
  993. inline file_t convertFDToNativeFile(int FD) { return FD; }
  994. #endif
  995.  
  996. /// Return an open handle to standard in. On Unix, this is typically FD 0.
  997. /// Returns kInvalidFile when the stream is closed.
  998. file_t getStdinHandle();
  999.  
  1000. /// Return an open handle to standard out. On Unix, this is typically FD 1.
  1001. /// Returns kInvalidFile when the stream is closed.
  1002. file_t getStdoutHandle();
  1003.  
  1004. /// Return an open handle to standard error. On Unix, this is typically FD 2.
  1005. /// Returns kInvalidFile when the stream is closed.
  1006. file_t getStderrHandle();
  1007.  
  1008. /// Reads \p Buf.size() bytes from \p FileHandle into \p Buf. Returns the number
  1009. /// of bytes actually read. On Unix, this is equivalent to `return ::read(FD,
  1010. /// Buf.data(), Buf.size())`, with error reporting. Returns 0 when reaching EOF.
  1011. ///
  1012. /// @param FileHandle File to read from.
  1013. /// @param Buf Buffer to read into.
  1014. /// @returns The number of bytes read, or error.
  1015. Expected<size_t> readNativeFile(file_t FileHandle, MutableArrayRef<char> Buf);
  1016.  
  1017. /// Default chunk size for \a readNativeFileToEOF().
  1018. enum : size_t { DefaultReadChunkSize = 4 * 4096 };
  1019.  
  1020. /// Reads from \p FileHandle until EOF, appending to \p Buffer in chunks of
  1021. /// size \p ChunkSize.
  1022. ///
  1023. /// This calls \a readNativeFile() in a loop. On Error, previous chunks that
  1024. /// were read successfully are left in \p Buffer and returned.
  1025. ///
  1026. /// Note: For reading the final chunk at EOF, \p Buffer's capacity needs extra
  1027. /// storage of \p ChunkSize.
  1028. ///
  1029. /// \param FileHandle File to read from.
  1030. /// \param Buffer Where to put the file content.
  1031. /// \param ChunkSize Size of chunks.
  1032. /// \returns The error if EOF was not found.
  1033. Error readNativeFileToEOF(file_t FileHandle, SmallVectorImpl<char> &Buffer,
  1034.                           ssize_t ChunkSize = DefaultReadChunkSize);
  1035.  
  1036. /// Reads \p Buf.size() bytes from \p FileHandle at offset \p Offset into \p
  1037. /// Buf. If 'pread' is available, this will use that, otherwise it will use
  1038. /// 'lseek'. Returns the number of bytes actually read. Returns 0 when reaching
  1039. /// EOF.
  1040. ///
  1041. /// @param FileHandle File to read from.
  1042. /// @param Buf Buffer to read into.
  1043. /// @param Offset Offset into the file at which the read should occur.
  1044. /// @returns The number of bytes read, or error.
  1045. Expected<size_t> readNativeFileSlice(file_t FileHandle,
  1046.                                      MutableArrayRef<char> Buf,
  1047.                                      uint64_t Offset);
  1048.  
  1049. /// @brief Opens the file with the given name in a write-only or read-write
  1050. /// mode, returning its open file descriptor. If the file does not exist, it
  1051. /// is created.
  1052. ///
  1053. /// The caller is responsible for closing the file descriptor once they are
  1054. /// finished with it.
  1055. ///
  1056. /// @param Name The path of the file to open, relative or absolute.
  1057. /// @param ResultFD If the file could be opened successfully, its descriptor
  1058. ///                 is stored in this location. Otherwise, this is set to -1.
  1059. /// @param Flags Additional flags used to determine whether the file should be
  1060. ///              opened in, for example, read-write or in write-only mode.
  1061. /// @param Mode The access permissions of the file, represented in octal.
  1062. /// @returns errc::success if \a Name has been opened, otherwise a
  1063. ///          platform-specific error_code.
  1064. inline std::error_code
  1065. openFileForWrite(const Twine &Name, int &ResultFD,
  1066.                  CreationDisposition Disp = CD_CreateAlways,
  1067.                  OpenFlags Flags = OF_None, unsigned Mode = 0666) {
  1068.   return openFile(Name, ResultFD, Disp, FA_Write, Flags, Mode);
  1069. }
  1070.  
  1071. /// @brief Opens the file with the given name in a write-only or read-write
  1072. /// mode, returning its open file descriptor. If the file does not exist, it
  1073. /// is created.
  1074. ///
  1075. /// The caller is responsible for closing the freeing the file once they are
  1076. /// finished with it.
  1077. ///
  1078. /// @param Name The path of the file to open, relative or absolute.
  1079. /// @param Flags Additional flags used to determine whether the file should be
  1080. ///              opened in, for example, read-write or in write-only mode.
  1081. /// @param Mode The access permissions of the file, represented in octal.
  1082. /// @returns a platform-specific file descriptor if \a Name has been opened,
  1083. ///          otherwise an error object.
  1084. inline Expected<file_t> openNativeFileForWrite(const Twine &Name,
  1085.                                                CreationDisposition Disp,
  1086.                                                OpenFlags Flags,
  1087.                                                unsigned Mode = 0666) {
  1088.   return openNativeFile(Name, Disp, FA_Write, Flags, Mode);
  1089. }
  1090.  
  1091. /// @brief Opens the file with the given name in a write-only or read-write
  1092. /// mode, returning its open file descriptor. If the file does not exist, it
  1093. /// is created.
  1094. ///
  1095. /// The caller is responsible for closing the file descriptor once they are
  1096. /// finished with it.
  1097. ///
  1098. /// @param Name The path of the file to open, relative or absolute.
  1099. /// @param ResultFD If the file could be opened successfully, its descriptor
  1100. ///                 is stored in this location. Otherwise, this is set to -1.
  1101. /// @param Flags Additional flags used to determine whether the file should be
  1102. ///              opened in, for example, read-write or in write-only mode.
  1103. /// @param Mode The access permissions of the file, represented in octal.
  1104. /// @returns errc::success if \a Name has been opened, otherwise a
  1105. ///          platform-specific error_code.
  1106. inline std::error_code openFileForReadWrite(const Twine &Name, int &ResultFD,
  1107.                                             CreationDisposition Disp,
  1108.                                             OpenFlags Flags,
  1109.                                             unsigned Mode = 0666) {
  1110.   return openFile(Name, ResultFD, Disp, FA_Write | FA_Read, Flags, Mode);
  1111. }
  1112.  
  1113. /// @brief Opens the file with the given name in a write-only or read-write
  1114. /// mode, returning its open file descriptor. If the file does not exist, it
  1115. /// is created.
  1116. ///
  1117. /// The caller is responsible for closing the freeing the file once they are
  1118. /// finished with it.
  1119. ///
  1120. /// @param Name The path of the file to open, relative or absolute.
  1121. /// @param Flags Additional flags used to determine whether the file should be
  1122. ///              opened in, for example, read-write or in write-only mode.
  1123. /// @param Mode The access permissions of the file, represented in octal.
  1124. /// @returns a platform-specific file descriptor if \a Name has been opened,
  1125. ///          otherwise an error object.
  1126. inline Expected<file_t> openNativeFileForReadWrite(const Twine &Name,
  1127.                                                    CreationDisposition Disp,
  1128.                                                    OpenFlags Flags,
  1129.                                                    unsigned Mode = 0666) {
  1130.   return openNativeFile(Name, Disp, FA_Write | FA_Read, Flags, Mode);
  1131. }
  1132.  
  1133. /// @brief Opens the file with the given name in a read-only mode, returning
  1134. /// its open file descriptor.
  1135. ///
  1136. /// The caller is responsible for closing the file descriptor once they are
  1137. /// finished with it.
  1138. ///
  1139. /// @param Name The path of the file to open, relative or absolute.
  1140. /// @param ResultFD If the file could be opened successfully, its descriptor
  1141. ///                 is stored in this location. Otherwise, this is set to -1.
  1142. /// @param RealPath If nonnull, extra work is done to determine the real path
  1143. ///                 of the opened file, and that path is stored in this
  1144. ///                 location.
  1145. /// @returns errc::success if \a Name has been opened, otherwise a
  1146. ///          platform-specific error_code.
  1147. std::error_code openFileForRead(const Twine &Name, int &ResultFD,
  1148.                                 OpenFlags Flags = OF_None,
  1149.                                 SmallVectorImpl<char> *RealPath = nullptr);
  1150.  
  1151. /// @brief Opens the file with the given name in a read-only mode, returning
  1152. /// its open file descriptor.
  1153. ///
  1154. /// The caller is responsible for closing the freeing the file once they are
  1155. /// finished with it.
  1156. ///
  1157. /// @param Name The path of the file to open, relative or absolute.
  1158. /// @param RealPath If nonnull, extra work is done to determine the real path
  1159. ///                 of the opened file, and that path is stored in this
  1160. ///                 location.
  1161. /// @returns a platform-specific file descriptor if \a Name has been opened,
  1162. ///          otherwise an error object.
  1163. Expected<file_t>
  1164. openNativeFileForRead(const Twine &Name, OpenFlags Flags = OF_None,
  1165.                       SmallVectorImpl<char> *RealPath = nullptr);
  1166.  
  1167. /// Try to locks the file during the specified time.
  1168. ///
  1169. /// This function implements advisory locking on entire file. If it returns
  1170. /// <em>errc::success</em>, the file is locked by the calling process. Until the
  1171. /// process unlocks the file by calling \a unlockFile, all attempts to lock the
  1172. /// same file will fail/block. The process that locked the file may assume that
  1173. /// none of other processes read or write this file, provided that all processes
  1174. /// lock the file prior to accessing its content.
  1175. ///
  1176. /// @param FD      The descriptor representing the file to lock.
  1177. /// @param Timeout Time in milliseconds that the process should wait before
  1178. ///                reporting lock failure. Zero value means try to get lock only
  1179. ///                once.
  1180. /// @returns errc::success if lock is successfully obtained,
  1181. /// errc::no_lock_available if the file cannot be locked, or platform-specific
  1182. /// error_code otherwise.
  1183. ///
  1184. /// @note Care should be taken when using this function in a multithreaded
  1185. /// context, as it may not prevent other threads in the same process from
  1186. /// obtaining a lock on the same file, even if they are using a different file
  1187. /// descriptor.
  1188. std::error_code
  1189. tryLockFile(int FD,
  1190.             std::chrono::milliseconds Timeout = std::chrono::milliseconds(0));
  1191.  
  1192. /// Lock the file.
  1193. ///
  1194. /// This function acts as @ref tryLockFile but it waits infinitely.
  1195. std::error_code lockFile(int FD);
  1196.  
  1197. /// Unlock the file.
  1198. ///
  1199. /// @param FD The descriptor representing the file to unlock.
  1200. /// @returns errc::success if lock is successfully released or platform-specific
  1201. /// error_code otherwise.
  1202. std::error_code unlockFile(int FD);
  1203.  
  1204. /// @brief Close the file object.  This should be used instead of ::close for
  1205. /// portability. On error, the caller should assume the file is closed, as is
  1206. /// the case for Process::SafelyCloseFileDescriptor
  1207. ///
  1208. /// @param F On input, this is the file to close.  On output, the file is
  1209. /// set to kInvalidFile.
  1210. ///
  1211. /// @returns An error code if closing the file failed. Typically, an error here
  1212. /// means that the filesystem may have failed to perform some buffered writes.
  1213. std::error_code closeFile(file_t &F);
  1214.  
  1215. #ifdef LLVM_ON_UNIX
  1216. /// @brief Change ownership of a file.
  1217. ///
  1218. /// @param Owner The owner of the file to change to.
  1219. /// @param Group The group of the file to change to.
  1220. /// @returns errc::success if successfully updated file ownership, otherwise an
  1221. ///          error code is returned.
  1222. std::error_code changeFileOwnership(int FD, uint32_t Owner, uint32_t Group);
  1223. #endif
  1224.  
  1225. /// RAII class that facilitates file locking.
  1226. class FileLocker {
  1227.   int FD; ///< Locked file handle.
  1228.   FileLocker(int FD) : FD(FD) {}
  1229.   friend class llvm::raw_fd_ostream;
  1230.  
  1231. public:
  1232.   FileLocker(const FileLocker &L) = delete;
  1233.   FileLocker(FileLocker &&L) : FD(L.FD) { L.FD = -1; }
  1234.   ~FileLocker() {
  1235.     if (FD != -1)
  1236.       unlockFile(FD);
  1237.   }
  1238.   FileLocker &operator=(FileLocker &&L) {
  1239.     FD = L.FD;
  1240.     L.FD = -1;
  1241.     return *this;
  1242.   }
  1243.   FileLocker &operator=(const FileLocker &L) = delete;
  1244.   std::error_code unlock() {
  1245.     if (FD != -1) {
  1246.       std::error_code Result = unlockFile(FD);
  1247.       FD = -1;
  1248.       return Result;
  1249.     }
  1250.     return std::error_code();
  1251.   }
  1252. };
  1253.  
  1254. std::error_code getUniqueID(const Twine Path, UniqueID &Result);
  1255.  
  1256. /// Get disk space usage information.
  1257. ///
  1258. /// Note: Users must be careful about "Time Of Check, Time Of Use" kind of bug.
  1259. /// Note: Windows reports results according to the quota allocated to the user.
  1260. ///
  1261. /// @param Path Input path.
  1262. /// @returns a space_info structure filled with the capacity, free, and
  1263. /// available space on the device \a Path is on. A platform specific error_code
  1264. /// is returned on error.
  1265. ErrorOr<space_info> disk_space(const Twine &Path);
  1266.  
  1267. /// This class represents a memory mapped file. It is based on
  1268. /// boost::iostreams::mapped_file.
  1269. class mapped_file_region {
  1270. public:
  1271.   enum mapmode {
  1272.     readonly, ///< May only access map via const_data as read only.
  1273.     readwrite, ///< May access map via data and modify it. Written to path.
  1274.     priv ///< May modify via data, but changes are lost on destruction.
  1275.   };
  1276.  
  1277. private:
  1278.   /// Platform-specific mapping state.
  1279.   size_t Size = 0;
  1280.   void *Mapping = nullptr;
  1281. #ifdef _WIN32
  1282.   sys::fs::file_t FileHandle = nullptr;
  1283. #endif
  1284.   mapmode Mode = readonly;
  1285.  
  1286.   void copyFrom(const mapped_file_region &Copied) {
  1287.     Size = Copied.Size;
  1288.     Mapping = Copied.Mapping;
  1289. #ifdef _WIN32
  1290.     FileHandle = Copied.FileHandle;
  1291. #endif
  1292.     Mode = Copied.Mode;
  1293.   }
  1294.  
  1295.   void moveFromImpl(mapped_file_region &Moved) {
  1296.     copyFrom(Moved);
  1297.     Moved.copyFrom(mapped_file_region());
  1298.   }
  1299.  
  1300.   void unmapImpl();
  1301.   void dontNeedImpl();
  1302.  
  1303.   std::error_code init(sys::fs::file_t FD, uint64_t Offset, mapmode Mode);
  1304.  
  1305. public:
  1306.   mapped_file_region() = default;
  1307.   mapped_file_region(mapped_file_region &&Moved) { moveFromImpl(Moved); }
  1308.   mapped_file_region &operator=(mapped_file_region &&Moved) {
  1309.     unmap();
  1310.     moveFromImpl(Moved);
  1311.     return *this;
  1312.   }
  1313.  
  1314.   mapped_file_region(const mapped_file_region &) = delete;
  1315.   mapped_file_region &operator=(const mapped_file_region &) = delete;
  1316.  
  1317.   /// \param fd An open file descriptor to map. Does not take ownership of fd.
  1318.   mapped_file_region(sys::fs::file_t fd, mapmode mode, size_t length, uint64_t offset,
  1319.                      std::error_code &ec);
  1320.  
  1321.   ~mapped_file_region() { unmapImpl(); }
  1322.  
  1323.   /// Check if this is a valid mapping.
  1324.   explicit operator bool() const { return Mapping; }
  1325.  
  1326.   /// Unmap.
  1327.   void unmap() {
  1328.     unmapImpl();
  1329.     copyFrom(mapped_file_region());
  1330.   }
  1331.   void dontNeed() { dontNeedImpl(); }
  1332.  
  1333.   size_t size() const;
  1334.   char *data() const;
  1335.  
  1336.   /// Get a const view of the data. Modifying this memory has undefined
  1337.   /// behavior.
  1338.   const char *const_data() const;
  1339.  
  1340.   /// \returns The minimum alignment offset must be.
  1341.   static int alignment();
  1342. };
  1343.  
  1344. /// Return the path to the main executable, given the value of argv[0] from
  1345. /// program startup and the address of main itself. In extremis, this function
  1346. /// may fail and return an empty path.
  1347. std::string getMainExecutable(const char *argv0, void *MainExecAddr);
  1348.  
  1349. /// @}
  1350. /// @name Iterators
  1351. /// @{
  1352.  
  1353. /// directory_entry - A single entry in a directory.
  1354. class directory_entry {
  1355.   // FIXME: different platforms make different information available "for free"
  1356.   // when traversing a directory. The design of this class wraps most of the
  1357.   // information in basic_file_status, so on platforms where we can't populate
  1358.   // that whole structure, callers end up paying for a stat().
  1359.   // std::filesystem::directory_entry may be a better model.
  1360.   std::string Path;
  1361.   file_type Type = file_type::type_unknown; // Most platforms can provide this.
  1362.   bool FollowSymlinks = true;               // Affects the behavior of status().
  1363.   basic_file_status Status;                 // If available.
  1364.  
  1365. public:
  1366.   explicit directory_entry(const Twine &Path, bool FollowSymlinks = true,
  1367.                            file_type Type = file_type::type_unknown,
  1368.                            basic_file_status Status = basic_file_status())
  1369.       : Path(Path.str()), Type(Type), FollowSymlinks(FollowSymlinks),
  1370.         Status(Status) {}
  1371.  
  1372.   directory_entry() = default;
  1373.  
  1374.   void replace_filename(const Twine &Filename, file_type Type,
  1375.                         basic_file_status Status = basic_file_status());
  1376.  
  1377.   const std::string &path() const { return Path; }
  1378.   // Get basic information about entry file (a subset of fs::status()).
  1379.   // On most platforms this is a stat() call.
  1380.   // On windows the information was already retrieved from the directory.
  1381.   ErrorOr<basic_file_status> status() const;
  1382.   // Get the type of this file.
  1383.   // On most platforms (Linux/Mac/Windows/BSD), this was already retrieved.
  1384.   // On some platforms (e.g. Solaris) this is a stat() call.
  1385.   file_type type() const {
  1386.     if (Type != file_type::type_unknown)
  1387.       return Type;
  1388.     auto S = status();
  1389.     return S ? S->type() : file_type::type_unknown;
  1390.   }
  1391.  
  1392.   bool operator==(const directory_entry& RHS) const { return Path == RHS.Path; }
  1393.   bool operator!=(const directory_entry& RHS) const { return !(*this == RHS); }
  1394.   bool operator< (const directory_entry& RHS) const;
  1395.   bool operator<=(const directory_entry& RHS) const;
  1396.   bool operator> (const directory_entry& RHS) const;
  1397.   bool operator>=(const directory_entry& RHS) const;
  1398. };
  1399.  
  1400. namespace detail {
  1401.  
  1402.   struct DirIterState;
  1403.  
  1404.   std::error_code directory_iterator_construct(DirIterState &, StringRef, bool);
  1405.   std::error_code directory_iterator_increment(DirIterState &);
  1406.   std::error_code directory_iterator_destruct(DirIterState &);
  1407.  
  1408.   /// Keeps state for the directory_iterator.
  1409.   struct DirIterState {
  1410.     ~DirIterState() {
  1411.       directory_iterator_destruct(*this);
  1412.     }
  1413.  
  1414.     intptr_t IterationHandle = 0;
  1415.     directory_entry CurrentEntry;
  1416.   };
  1417.  
  1418. } // end namespace detail
  1419.  
  1420. /// directory_iterator - Iterates through the entries in path. There is no
  1421. /// operator++ because we need an error_code. If it's really needed we can make
  1422. /// it call report_fatal_error on error.
  1423. class directory_iterator {
  1424.   std::shared_ptr<detail::DirIterState> State;
  1425.   bool FollowSymlinks = true;
  1426.  
  1427. public:
  1428.   explicit directory_iterator(const Twine &path, std::error_code &ec,
  1429.                               bool follow_symlinks = true)
  1430.       : FollowSymlinks(follow_symlinks) {
  1431.     State = std::make_shared<detail::DirIterState>();
  1432.     SmallString<128> path_storage;
  1433.     ec = detail::directory_iterator_construct(
  1434.         *State, path.toStringRef(path_storage), FollowSymlinks);
  1435.   }
  1436.  
  1437.   explicit directory_iterator(const directory_entry &de, std::error_code &ec,
  1438.                               bool follow_symlinks = true)
  1439.       : FollowSymlinks(follow_symlinks) {
  1440.     State = std::make_shared<detail::DirIterState>();
  1441.     ec = detail::directory_iterator_construct(
  1442.         *State, de.path(), FollowSymlinks);
  1443.   }
  1444.  
  1445.   /// Construct end iterator.
  1446.   directory_iterator() = default;
  1447.  
  1448.   // No operator++ because we need error_code.
  1449.   directory_iterator &increment(std::error_code &ec) {
  1450.     ec = directory_iterator_increment(*State);
  1451.     return *this;
  1452.   }
  1453.  
  1454.   const directory_entry &operator*() const { return State->CurrentEntry; }
  1455.   const directory_entry *operator->() const { return &State->CurrentEntry; }
  1456.  
  1457.   bool operator==(const directory_iterator &RHS) const {
  1458.     if (State == RHS.State)
  1459.       return true;
  1460.     if (!RHS.State)
  1461.       return State->CurrentEntry == directory_entry();
  1462.     if (!State)
  1463.       return RHS.State->CurrentEntry == directory_entry();
  1464.     return State->CurrentEntry == RHS.State->CurrentEntry;
  1465.   }
  1466.  
  1467.   bool operator!=(const directory_iterator &RHS) const {
  1468.     return !(*this == RHS);
  1469.   }
  1470. };
  1471.  
  1472. namespace detail {
  1473.  
  1474.   /// Keeps state for the recursive_directory_iterator.
  1475.   struct RecDirIterState {
  1476.     std::stack<directory_iterator, std::vector<directory_iterator>> Stack;
  1477.     uint16_t Level = 0;
  1478.     bool HasNoPushRequest = false;
  1479.   };
  1480.  
  1481. } // end namespace detail
  1482.  
  1483. /// recursive_directory_iterator - Same as directory_iterator except for it
  1484. /// recurses down into child directories.
  1485. class recursive_directory_iterator {
  1486.   std::shared_ptr<detail::RecDirIterState> State;
  1487.   bool Follow;
  1488.  
  1489. public:
  1490.   recursive_directory_iterator() = default;
  1491.   explicit recursive_directory_iterator(const Twine &path, std::error_code &ec,
  1492.                                         bool follow_symlinks = true)
  1493.       : State(std::make_shared<detail::RecDirIterState>()),
  1494.         Follow(follow_symlinks) {
  1495.     State->Stack.push(directory_iterator(path, ec, Follow));
  1496.     if (State->Stack.top() == directory_iterator())
  1497.       State.reset();
  1498.   }
  1499.  
  1500.   // No operator++ because we need error_code.
  1501.   recursive_directory_iterator &increment(std::error_code &ec) {
  1502.     const directory_iterator end_itr = {};
  1503.  
  1504.     if (State->HasNoPushRequest)
  1505.       State->HasNoPushRequest = false;
  1506.     else {
  1507.       file_type type = State->Stack.top()->type();
  1508.       if (type == file_type::symlink_file && Follow) {
  1509.         // Resolve the symlink: is it a directory to recurse into?
  1510.         ErrorOr<basic_file_status> status = State->Stack.top()->status();
  1511.         if (status)
  1512.           type = status->type();
  1513.         // Otherwise broken symlink, and we'll continue.
  1514.       }
  1515.       if (type == file_type::directory_file) {
  1516.         State->Stack.push(directory_iterator(*State->Stack.top(), ec, Follow));
  1517.         if (State->Stack.top() != end_itr) {
  1518.           ++State->Level;
  1519.           return *this;
  1520.         }
  1521.         State->Stack.pop();
  1522.       }
  1523.     }
  1524.  
  1525.     while (!State->Stack.empty()
  1526.            && State->Stack.top().increment(ec) == end_itr) {
  1527.       State->Stack.pop();
  1528.       --State->Level;
  1529.     }
  1530.  
  1531.     // Check if we are done. If so, create an end iterator.
  1532.     if (State->Stack.empty())
  1533.       State.reset();
  1534.  
  1535.     return *this;
  1536.   }
  1537.  
  1538.   const directory_entry &operator*() const { return *State->Stack.top(); }
  1539.   const directory_entry *operator->() const { return &*State->Stack.top(); }
  1540.  
  1541.   // observers
  1542.   /// Gets the current level. Starting path is at level 0.
  1543.   int level() const { return State->Level; }
  1544.  
  1545.   /// Returns true if no_push has been called for this directory_entry.
  1546.   bool no_push_request() const { return State->HasNoPushRequest; }
  1547.  
  1548.   // modifiers
  1549.   /// Goes up one level if Level > 0.
  1550.   void pop() {
  1551.     assert(State && "Cannot pop an end iterator!");
  1552.     assert(State->Level > 0 && "Cannot pop an iterator with level < 1");
  1553.  
  1554.     const directory_iterator end_itr = {};
  1555.     std::error_code ec;
  1556.     do {
  1557.       if (ec)
  1558.         report_fatal_error("Error incrementing directory iterator.");
  1559.       State->Stack.pop();
  1560.       --State->Level;
  1561.     } while (!State->Stack.empty()
  1562.              && State->Stack.top().increment(ec) == end_itr);
  1563.  
  1564.     // Check if we are done. If so, create an end iterator.
  1565.     if (State->Stack.empty())
  1566.       State.reset();
  1567.   }
  1568.  
  1569.   /// Does not go down into the current directory_entry.
  1570.   void no_push() { State->HasNoPushRequest = true; }
  1571.  
  1572.   bool operator==(const recursive_directory_iterator &RHS) const {
  1573.     return State == RHS.State;
  1574.   }
  1575.  
  1576.   bool operator!=(const recursive_directory_iterator &RHS) const {
  1577.     return !(*this == RHS);
  1578.   }
  1579. };
  1580.  
  1581. /// @}
  1582.  
  1583. } // end namespace fs
  1584. } // end namespace sys
  1585. } // end namespace llvm
  1586.  
  1587. #endif // LLVM_SUPPORT_FILESYSTEM_H
  1588.