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1 //===- llvm/Support/PathV1.h - Path Operating System Concept ----*- 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 declares the llvm::sys::Path class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_SUPPORT_PATHV1_H
15 #define LLVM_SUPPORT_PATHV1_H
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/Support/Compiler.h"
19 #include "llvm/Support/TimeValue.h"
20 #include <set>
21 #include <string>
22 #include <vector>
23 
24 #define LLVM_PATH_DEPRECATED_MSG(replacement) \
25   "PathV1 has been deprecated and will be removed as soon as all LLVM and" \
26   " Clang clients have been moved over to PathV2. Please use `" #replacement \
27   "` from PathV2 instead."
28 
29 namespace llvm {
30 namespace sys {
31 
32   /// This structure provides basic file system information about a file. It
33   /// is patterned after the stat(2) Unix operating system call but made
34   /// platform independent and eliminates many of the unix-specific fields.
35   /// However, to support llvm-ar, the mode, user, and group fields are
36   /// retained. These pertain to unix security and may not have a meaningful
37   /// value on non-Unix platforms. However, the other fields should
38   /// always be applicable on all platforms.  The structure is filled in by
39   /// the PathWithStatus class.
40   /// @brief File status structure
41   class FileStatus {
42   public:
43     uint64_t    fileSize;   ///< Size of the file in bytes
44     TimeValue   modTime;    ///< Time of file's modification
45     uint32_t    mode;       ///< Mode of the file, if applicable
46     uint32_t    user;       ///< User ID of owner, if applicable
47     uint32_t    group;      ///< Group ID of owner, if applicable
48     uint64_t    uniqueID;   ///< A number to uniquely ID this file
49     bool        isDir  : 1; ///< True if this is a directory.
50     bool        isFile : 1; ///< True if this is a file.
51 
FileStatus()52     FileStatus() : fileSize(0), modTime(0,0), mode(0777), user(999),
53                    group(999), uniqueID(0), isDir(false), isFile(false) { }
54 
getTimestamp()55     TimeValue getTimestamp() const { return modTime; }
getSize()56     uint64_t getSize() const { return fileSize; }
getMode()57     uint32_t getMode() const { return mode; }
getUser()58     uint32_t getUser() const { return user; }
getGroup()59     uint32_t getGroup() const { return group; }
getUniqueID()60     uint64_t getUniqueID() const { return uniqueID; }
61   };
62 
63   /// This class provides an abstraction for the path to a file or directory
64   /// in the operating system's filesystem and provides various basic operations
65   /// on it.  Note that this class only represents the name of a path to a file
66   /// or directory which may or may not be valid for a given machine's file
67   /// system. The class is patterned after the java.io.File class with various
68   /// extensions and several omissions (not relevant to LLVM).  A Path object
69   /// ensures that the path it encapsulates is syntactically valid for the
70   /// operating system it is running on but does not ensure correctness for
71   /// any particular file system. That is, a syntactically valid path might
72   /// specify path components that do not exist in the file system and using
73   /// such a Path to act on the file system could produce errors. There is one
74   /// invalid Path value which is permitted: the empty path.  The class should
75   /// never allow a syntactically invalid non-empty path name to be assigned.
76   /// Empty paths are required in order to indicate an error result in some
77   /// situations. If the path is empty, the isValid operation will return
78   /// false. All operations will fail if isValid is false. Operations that
79   /// change the path will either return false if it would cause a syntactically
80   /// invalid path name (in which case the Path object is left unchanged) or
81   /// throw an std::string exception indicating the error. The methods are
82   /// grouped into four basic categories: Path Accessors (provide information
83   /// about the path without accessing disk), Disk Accessors (provide
84   /// information about the underlying file or directory), Path Mutators
85   /// (change the path information, not the disk), and Disk Mutators (change
86   /// the disk file/directory referenced by the path). The Disk Mutator methods
87   /// all have the word "disk" embedded in their method name to reinforce the
88   /// notion that the operation modifies the file system.
89   /// @since 1.4
90   /// @brief An abstraction for operating system paths.
91   class Path {
92     /// @name Constructors
93     /// @{
94     public:
95       /// Construct a path to the root directory of the file system. The root
96       /// directory is a top level directory above which there are no more
97       /// directories. For example, on UNIX, the root directory is /. On Windows
98       /// it is file:///. Other operating systems may have different notions of
99       /// what the root directory is or none at all. In that case, a consistent
100       /// default root directory will be used.
101       LLVM_ATTRIBUTE_DEPRECATED(static Path GetRootDirectory(),
102         LLVM_PATH_DEPRECATED_MSG(NOTHING));
103 
104       /// Construct a path to a unique temporary directory that is created in
105       /// a "standard" place for the operating system. The directory is
106       /// guaranteed to be created on exit from this function. If the directory
107       /// cannot be created, the function will throw an exception.
108       /// @returns an invalid path (empty) on error
109       /// @param ErrMsg Optional place for an error message if an error occurs
110       /// @brief Construct a path to an new, unique, existing temporary
111       /// directory.
112       static Path GetTemporaryDirectory(std::string* ErrMsg = 0);
113 
114       /// Construct a vector of sys::Path that contains the "standard" system
115       /// library paths suitable for linking into programs.
116       /// @brief Construct a path to the system library directory
117       static void GetSystemLibraryPaths(std::vector<sys::Path>& Paths);
118 
119       /// Construct a vector of sys::Path that contains the "standard" bitcode
120       /// library paths suitable for linking into an llvm program. This function
121       /// *must* return the value of LLVM_LIB_SEARCH_PATH as well as the value
122       /// of LLVM_LIBDIR. It also must provide the System library paths as
123       /// returned by GetSystemLibraryPaths.
124       /// @see GetSystemLibraryPaths
125       /// @brief Construct a list of directories in which bitcode could be
126       /// found.
127       static void GetBitcodeLibraryPaths(std::vector<sys::Path>& Paths);
128 
129       /// Find the path to a library using its short name. Use the system
130       /// dependent library paths to locate the library.
131       /// @brief Find a library.
132       static Path FindLibrary(std::string& short_name);
133 
134       /// Construct a path to the current user's home directory. The
135       /// implementation must use an operating system specific mechanism for
136       /// determining the user's home directory. For example, the environment
137       /// variable "HOME" could be used on Unix. If a given operating system
138       /// does not have the concept of a user's home directory, this static
139       /// constructor must provide the same result as GetRootDirectory.
140       /// @brief Construct a path to the current user's "home" directory
141       static Path GetUserHomeDirectory();
142 
143       /// Construct a path to the current directory for the current process.
144       /// @returns The current working directory.
145       /// @brief Returns the current working directory.
146       static Path GetCurrentDirectory();
147 
148       /// Return the suffix commonly used on file names that contain an
149       /// executable.
150       /// @returns The executable file suffix for the current platform.
151       /// @brief Return the executable file suffix.
152       static StringRef GetEXESuffix();
153 
154       /// Return the suffix commonly used on file names that contain a shared
155       /// object, shared archive, or dynamic link library. Such files are
156       /// linked at runtime into a process and their code images are shared
157       /// between processes.
158       /// @returns The dynamic link library suffix for the current platform.
159       /// @brief Return the dynamic link library suffix.
160       static StringRef GetDLLSuffix();
161 
162       /// GetMainExecutable - Return the path to the main executable, given the
163       /// value of argv[0] from program startup and the address of main itself.
164       /// In extremis, this function may fail and return an empty path.
165       static Path GetMainExecutable(const char *argv0, void *MainAddr);
166 
167       /// This is one of the very few ways in which a path can be constructed
168       /// with a syntactically invalid name. The only *legal* invalid name is an
169       /// empty one. Other invalid names are not permitted. Empty paths are
170       /// provided so that they can be used to indicate null or error results in
171       /// other lib/System functionality.
172       /// @brief Construct an empty (and invalid) path.
Path()173       Path() : path() {}
Path(const Path & that)174       Path(const Path &that) : path(that.path) {}
175 
176       /// This constructor will accept a char* or std::string as a path. No
177       /// checking is done on this path to determine if it is valid. To
178       /// determine validity of the path, use the isValid method.
179       /// @param p The path to assign.
180       /// @brief Construct a Path from a string.
181       explicit Path(StringRef p);
182 
183       /// This constructor will accept a character range as a path.  No checking
184       /// is done on this path to determine if it is valid.  To determine
185       /// validity of the path, use the isValid method.
186       /// @param StrStart A pointer to the first character of the path name
187       /// @param StrLen The length of the path name at StrStart
188       /// @brief Construct a Path from a string.
189       Path(const char *StrStart, unsigned StrLen);
190 
191     /// @}
192     /// @name Operators
193     /// @{
194     public:
195       /// Makes a copy of \p that to \p this.
196       /// @returns \p this
197       /// @brief Assignment Operator
198       Path &operator=(const Path &that) {
199         path = that.path;
200         return *this;
201       }
202 
203       /// Makes a copy of \p that to \p this.
204       /// @param that A StringRef denoting the path
205       /// @returns \p this
206       /// @brief Assignment Operator
207       Path &operator=(StringRef that);
208 
209       /// Compares \p this Path with \p that Path for equality.
210       /// @returns true if \p this and \p that refer to the same thing.
211       /// @brief Equality Operator
212       bool operator==(const Path &that) const;
213 
214       /// Compares \p this Path with \p that Path for inequality.
215       /// @returns true if \p this and \p that refer to different things.
216       /// @brief Inequality Operator
217       bool operator!=(const Path &that) const { return !(*this == that); }
218 
219       /// Determines if \p this Path is less than \p that Path. This is required
220       /// so that Path objects can be placed into ordered collections (e.g.
221       /// std::map). The comparison is done lexicographically as defined by
222       /// the std::string::compare method.
223       /// @returns true if \p this path is lexicographically less than \p that.
224       /// @brief Less Than Operator
225       bool operator<(const Path& that) const;
226 
227     /// @}
228     /// @name Path Accessors
229     /// @{
230     public:
231       /// This function will use an operating system specific algorithm to
232       /// determine if the current value of \p this is a syntactically valid
233       /// path name for the operating system. The path name does not need to
234       /// exist, validity is simply syntactical. Empty paths are always invalid.
235       /// @returns true iff the path name is syntactically legal for the
236       /// host operating system.
237       /// @brief Determine if a path is syntactically valid or not.
238       bool isValid() const;
239 
240       /// This function determines if the contents of the path name are empty.
241       /// That is, the path name has a zero length. This does NOT determine if
242       /// if the file is empty. To get the length of the file itself, Use the
243       /// PathWithStatus::getFileStatus() method and then the getSize() method
244       /// on the returned FileStatus object.
245       /// @returns true iff the path is empty.
246       /// @brief Determines if the path name is empty (invalid).
isEmpty()247       bool isEmpty() const { return path.empty(); }
248 
249        /// This function returns the last component of the path name. The last
250       /// component is the file or directory name occurring after the last
251       /// directory separator. If no directory separator is present, the entire
252       /// path name is returned (i.e. same as toString).
253       /// @returns StringRef containing the last component of the path name.
254       /// @brief Returns the last component of the path name.
255       LLVM_ATTRIBUTE_DEPRECATED(
256         StringRef getLast() const,
257         LLVM_PATH_DEPRECATED_MSG(path::filename));
258 
259       /// This function strips off the path and suffix of the file or directory
260       /// name and returns just the basename. For example /a/foo.bar would cause
261       /// this function to return "foo".
262       /// @returns StringRef containing the basename of the path
263       /// @brief Get the base name of the path
264       LLVM_ATTRIBUTE_DEPRECATED(StringRef getBasename() const,
265         LLVM_PATH_DEPRECATED_MSG(path::stem));
266 
267       /// This function strips off the suffix of the path beginning with the
268       /// path separator ('/' on Unix, '\' on Windows) and returns the result.
269       LLVM_ATTRIBUTE_DEPRECATED(StringRef getDirname() const,
270         LLVM_PATH_DEPRECATED_MSG(path::parent_path));
271 
272       /// This function strips off the path and basename(up to and
273       /// including the last dot) of the file or directory name and
274       /// returns just the suffix. For example /a/foo.bar would cause
275       /// this function to return "bar".
276       /// @returns StringRef containing the suffix of the path
277       /// @brief Get the suffix of the path
278       LLVM_ATTRIBUTE_DEPRECATED(StringRef getSuffix() const,
279         LLVM_PATH_DEPRECATED_MSG(path::extension));
280 
281       /// Obtain a 'C' string for the path name.
282       /// @returns a 'C' string containing the path name.
283       /// @brief Returns the path as a C string.
c_str()284       const char *c_str() const { return path.c_str(); }
str()285       const std::string &str() const { return path; }
286 
287 
288       /// size - Return the length in bytes of this path name.
size()289       size_t size() const { return path.size(); }
290 
291       /// empty - Returns true if the path is empty.
empty()292       unsigned empty() const { return path.empty(); }
293 
294     /// @}
295     /// @name Disk Accessors
296     /// @{
297     public:
298       /// This function determines if the path name is absolute, as opposed to
299       /// relative.
300       /// @brief Determine if the path is absolute.
301       LLVM_ATTRIBUTE_DEPRECATED(
302         bool isAbsolute() const,
303         LLVM_PATH_DEPRECATED_MSG(path::is_absolute));
304 
305       /// This function determines if the path name is absolute, as opposed to
306       /// relative.
307       /// @brief Determine if the path is absolute.
308       LLVM_ATTRIBUTE_DEPRECATED(
309         static bool isAbsolute(const char *NameStart, unsigned NameLen),
310         LLVM_PATH_DEPRECATED_MSG(path::is_absolute));
311 
312       /// This function opens the file associated with the path name provided by
313       /// the Path object and reads its magic number. If the magic number at the
314       /// start of the file matches \p magic, true is returned. In all other
315       /// cases (file not found, file not accessible, etc.) it returns false.
316       /// @returns true if the magic number of the file matches \p magic.
317       /// @brief Determine if file has a specific magic number
318       LLVM_ATTRIBUTE_DEPRECATED(bool hasMagicNumber(StringRef magic) const,
319         LLVM_PATH_DEPRECATED_MSG(fs::has_magic));
320 
321       /// This function retrieves the first \p len bytes of the file associated
322       /// with \p this. These bytes are returned as the "magic number" in the
323       /// \p Magic parameter.
324       /// @returns true if the Path is a file and the magic number is retrieved,
325       /// false otherwise.
326       /// @brief Get the file's magic number.
327       bool getMagicNumber(std::string& Magic, unsigned len) const;
328 
329       /// This function determines if the path name in the object references an
330       /// archive file by looking at its magic number.
331       /// @returns true if the file starts with the magic number for an archive
332       /// file.
333       /// @brief Determine if the path references an archive file.
334       bool isArchive() const;
335 
336       /// This function determines if the path name in the object references an
337       /// LLVM Bitcode file by looking at its magic number.
338       /// @returns true if the file starts with the magic number for LLVM
339       /// bitcode files.
340       /// @brief Determine if the path references a bitcode file.
341       bool isBitcodeFile() const;
342 
343       /// This function determines if the path name in the object references a
344       /// native Dynamic Library (shared library, shared object) by looking at
345       /// the file's magic number. The Path object must reference a file, not a
346       /// directory.
347       /// @returns true if the file starts with the magic number for a native
348       /// shared library.
349       /// @brief Determine if the path references a dynamic library.
350       bool isDynamicLibrary() const;
351 
352       /// This function determines if the path name in the object references a
353       /// native object file by looking at it's magic number. The term object
354       /// file is defined as "an organized collection of separate, named
355       /// sequences of binary data." This covers the obvious file formats such
356       /// as COFF and ELF, but it also includes llvm ir bitcode, archives,
357       /// libraries, etc...
358       /// @returns true if the file starts with the magic number for an object
359       /// file.
360       /// @brief Determine if the path references an object file.
361       bool isObjectFile() const;
362 
363       /// This function determines if the path name references an existing file
364       /// or directory in the file system.
365       /// @returns true if the pathname references an existing file or
366       /// directory.
367       /// @brief Determines if the path is a file or directory in
368       /// the file system.
369       LLVM_ATTRIBUTE_DEPRECATED(bool exists() const,
370         LLVM_PATH_DEPRECATED_MSG(fs::exists));
371 
372       /// This function determines if the path name references an
373       /// existing directory.
374       /// @returns true if the pathname references an existing directory.
375       /// @brief Determines if the path is a directory in the file system.
376       LLVM_ATTRIBUTE_DEPRECATED(bool isDirectory() const,
377         LLVM_PATH_DEPRECATED_MSG(fs::is_directory));
378 
379       /// This function determines if the path name references an
380       /// existing symbolic link.
381       /// @returns true if the pathname references an existing symlink.
382       /// @brief Determines if the path is a symlink in the file system.
383       LLVM_ATTRIBUTE_DEPRECATED(bool isSymLink() const,
384         LLVM_PATH_DEPRECATED_MSG(fs::is_symlink));
385 
386       /// This function determines if the path name references a readable file
387       /// or directory in the file system. This function checks for
388       /// the existence and readability (by the current program) of the file
389       /// or directory.
390       /// @returns true if the pathname references a readable file.
391       /// @brief Determines if the path is a readable file or directory
392       /// in the file system.
393       bool canRead() const;
394 
395       /// This function determines if the path name references a writable file
396       /// or directory in the file system. This function checks for the
397       /// existence and writability (by the current program) of the file or
398       /// directory.
399       /// @returns true if the pathname references a writable file.
400       /// @brief Determines if the path is a writable file or directory
401       /// in the file system.
402       bool canWrite() const;
403 
404       /// This function checks that what we're trying to work only on a regular
405       /// file. Check for things like /dev/null, any block special file, or
406       /// other things that aren't "regular" regular files.
407       /// @returns true if the file is S_ISREG.
408       /// @brief Determines if the file is a regular file
409       bool isRegularFile() const;
410 
411       /// This function determines if the path name references an executable
412       /// file in the file system. This function checks for the existence and
413       /// executability (by the current program) of the file.
414       /// @returns true if the pathname references an executable file.
415       /// @brief Determines if the path is an executable file in the file
416       /// system.
417       bool canExecute() const;
418 
419       /// This function builds a list of paths that are the names of the
420       /// files and directories in a directory.
421       /// @returns true if an error occurs, true otherwise
422       /// @brief Build a list of directory's contents.
423       bool getDirectoryContents(
424         std::set<Path> &paths, ///< The resulting list of file & directory names
425         std::string* ErrMsg    ///< Optional place to return an error message.
426       ) const;
427 
428     /// @}
429     /// @name Path Mutators
430     /// @{
431     public:
432       /// The path name is cleared and becomes empty. This is an invalid
433       /// path name but is the *only* invalid path name. This is provided
434       /// so that path objects can be used to indicate the lack of a
435       /// valid path being found.
436       /// @brief Make the path empty.
clear()437       void clear() { path.clear(); }
438 
439       /// This method sets the Path object to \p unverified_path. This can fail
440       /// if the \p unverified_path does not pass the syntactic checks of the
441       /// isValid() method. If verification fails, the Path object remains
442       /// unchanged and false is returned. Otherwise true is returned and the
443       /// Path object takes on the path value of \p unverified_path
444       /// @returns true if the path was set, false otherwise.
445       /// @param unverified_path The path to be set in Path object.
446       /// @brief Set a full path from a StringRef
447       bool set(StringRef unverified_path);
448 
449       /// One path component is removed from the Path. If only one component is
450       /// present in the path, the Path object becomes empty. If the Path object
451       /// is empty, no change is made.
452       /// @returns false if the path component could not be removed.
453       /// @brief Removes the last directory component of the Path.
454       bool eraseComponent();
455 
456       /// The \p component is added to the end of the Path if it is a legal
457       /// name for the operating system. A directory separator will be added if
458       /// needed.
459       /// @returns false if the path component could not be added.
460       /// @brief Appends one path component to the Path.
461       bool appendComponent(StringRef component);
462 
463       /// A period and the \p suffix are appended to the end of the pathname.
464       /// When the \p suffix is empty, no action is performed.
465       /// @brief Adds a period and the \p suffix to the end of the pathname.
466       void appendSuffix(StringRef suffix);
467 
468       /// The suffix of the filename is erased. The suffix begins with and
469       /// includes the last . character in the filename after the last directory
470       /// separator and extends until the end of the name. If no . character is
471       /// after the last directory separator, then the file name is left
472       /// unchanged (i.e. it was already without a suffix) but the function
473       /// returns false.
474       /// @returns false if there was no suffix to remove, true otherwise.
475       /// @brief Remove the suffix from a path name.
476       bool eraseSuffix();
477 
478       /// The current Path name is made unique in the file system. Upon return,
479       /// the Path will have been changed to make a unique file in the file
480       /// system or it will not have been changed if the current path name is
481       /// already unique.
482       /// @throws std::string if an unrecoverable error occurs.
483       /// @brief Make the current path name unique in the file system.
484       bool makeUnique( bool reuse_current /*= true*/, std::string* ErrMsg );
485 
486       /// The current Path name is made absolute by prepending the
487       /// current working directory if necessary.
488       LLVM_ATTRIBUTE_DEPRECATED(
489         void makeAbsolute(),
490         LLVM_PATH_DEPRECATED_MSG(fs::make_absolute));
491 
492     /// @}
493     /// @name Disk Mutators
494     /// @{
495     public:
496       /// This method attempts to make the file referenced by the Path object
497       /// available for reading so that the canRead() method will return true.
498       /// @brief Make the file readable;
499       bool makeReadableOnDisk(std::string* ErrMsg = 0);
500 
501       /// This method attempts to make the file referenced by the Path object
502       /// available for writing so that the canWrite() method will return true.
503       /// @brief Make the file writable;
504       bool makeWriteableOnDisk(std::string* ErrMsg = 0);
505 
506       /// This method attempts to make the file referenced by the Path object
507       /// available for execution so that the canExecute() method will return
508       /// true.
509       /// @brief Make the file readable;
510       bool makeExecutableOnDisk(std::string* ErrMsg = 0);
511 
512       /// This method allows the last modified time stamp and permission bits
513       /// to be set on the disk object referenced by the Path.
514       /// @throws std::string if an error occurs.
515       /// @returns true on error.
516       /// @brief Set the status information.
517       bool setStatusInfoOnDisk(const FileStatus &SI,
518                                std::string *ErrStr = 0) const;
519 
520       /// This method attempts to create a directory in the file system with the
521       /// same name as the Path object. The \p create_parents parameter controls
522       /// whether intermediate directories are created or not. if \p
523       /// create_parents is true, then an attempt will be made to create all
524       /// intermediate directories, as needed. If \p create_parents is false,
525       /// then only the final directory component of the Path name will be
526       /// created. The created directory will have no entries.
527       /// @returns true if the directory could not be created, false otherwise
528       /// @brief Create the directory this Path refers to.
529       bool createDirectoryOnDisk(
530         bool create_parents = false, ///<  Determines whether non-existent
531            ///< directory components other than the last one (the "parents")
532            ///< are created or not.
533         std::string* ErrMsg = 0 ///< Optional place to put error messages.
534       );
535 
536       /// This method attempts to create a file in the file system with the same
537       /// name as the Path object. The intermediate directories must all exist
538       /// at the time this method is called. Use createDirectoriesOnDisk to
539       /// accomplish that. The created file will be empty upon return from this
540       /// function.
541       /// @returns true if the file could not be created, false otherwise.
542       /// @brief Create the file this Path refers to.
543       bool createFileOnDisk(
544         std::string* ErrMsg = 0 ///< Optional place to put error messages.
545       );
546 
547       /// This is like createFile except that it creates a temporary file. A
548       /// unique temporary file name is generated based on the contents of
549       /// \p this before the call. The new name is assigned to \p this and the
550       /// file is created.  Note that this will both change the Path object
551       /// *and* create the corresponding file. This function will ensure that
552       /// the newly generated temporary file name is unique in the file system.
553       /// @returns true if the file couldn't be created, false otherwise.
554       /// @brief Create a unique temporary file
555       bool createTemporaryFileOnDisk(
556         bool reuse_current = false, ///< When set to true, this parameter
557           ///< indicates that if the current file name does not exist then
558           ///< it will be used without modification.
559         std::string* ErrMsg = 0 ///< Optional place to put error messages
560       );
561 
562       /// This method renames the file referenced by \p this as \p newName. The
563       /// file referenced by \p this must exist. The file referenced by
564       /// \p newName does not need to exist.
565       /// @returns true on error, false otherwise
566       /// @brief Rename one file as another.
567       bool renamePathOnDisk(const Path& newName, std::string* ErrMsg);
568 
569       /// This method attempts to destroy the file or directory named by the
570       /// last component of the Path. If the Path refers to a directory and the
571       /// \p destroy_contents is false, an attempt will be made to remove just
572       /// the directory (the final Path component). If \p destroy_contents is
573       /// true, an attempt will be made to remove the entire contents of the
574       /// directory, recursively. If the Path refers to a file, the
575       /// \p destroy_contents parameter is ignored.
576       /// @param destroy_contents Indicates whether the contents of a destroyed
577       /// @param Err An optional string to receive an error message.
578       /// directory should also be destroyed (recursively).
579       /// @returns false if the file/directory was destroyed, true on error.
580       /// @brief Removes the file or directory from the filesystem.
581       bool eraseFromDisk(bool destroy_contents = false,
582                          std::string *Err = 0) const;
583 
584 
585       /// MapInFilePages - This is a low level system API to map in the file
586       /// that is currently opened as FD into the current processes' address
587       /// space for read only access.  This function may return null on failure
588       /// or if the system cannot provide the following constraints:
589       ///  1) The pages must be valid after the FD is closed, until
590       ///     UnMapFilePages is called.
591       ///  2) Any padding after the end of the file must be zero filled, if
592       ///     present.
593       ///  3) The pages must be contiguous.
594       ///
595       /// This API is not intended for general use, clients should use
596       /// MemoryBuffer::getFile instead.
597       static const char *MapInFilePages(int FD, size_t FileSize,
598                                         off_t Offset);
599 
600       /// UnMapFilePages - Free pages mapped into the current process by
601       /// MapInFilePages.
602       ///
603       /// This API is not intended for general use, clients should use
604       /// MemoryBuffer::getFile instead.
605       static void UnMapFilePages(const char *Base, size_t FileSize);
606 
607     /// @}
608     /// @name Data
609     /// @{
610     protected:
611       // Our win32 implementation relies on this string being mutable.
612       mutable std::string path;   ///< Storage for the path name.
613 
614 
615     /// @}
616   };
617 
618   /// This class is identical to Path class except it allows you to obtain the
619   /// file status of the Path as well. The reason for the distinction is one of
620   /// efficiency. First, the file status requires additional space and the space
621   /// is incorporated directly into PathWithStatus without an additional malloc.
622   /// Second, obtaining status information is an expensive operation on most
623   /// operating systems so we want to be careful and explicit about where we
624   /// allow this operation in LLVM.
625   /// @brief Path with file status class.
626   class PathWithStatus : public Path {
627     /// @name Constructors
628     /// @{
629     public:
630       /// @brief Default constructor
PathWithStatus()631       PathWithStatus() : Path(), status(), fsIsValid(false) {}
632 
633       /// @brief Copy constructor
PathWithStatus(const PathWithStatus & that)634       PathWithStatus(const PathWithStatus &that)
635         : Path(static_cast<const Path&>(that)), status(that.status),
636            fsIsValid(that.fsIsValid) {}
637 
638       /// This constructor allows construction from a Path object
639       /// @brief Path constructor
PathWithStatus(const Path & other)640       PathWithStatus(const Path &other)
641         : Path(other), status(), fsIsValid(false) {}
642 
643       /// This constructor will accept a char* or std::string as a path. No
644       /// checking is done on this path to determine if it is valid. To
645       /// determine validity of the path, use the isValid method.
646       /// @brief Construct a Path from a string.
PathWithStatus(StringRef p)647       explicit PathWithStatus(
648         StringRef p ///< The path to assign.
649       ) : Path(p), status(), fsIsValid(false) {}
650 
651       /// This constructor will accept a character range as a path.  No checking
652       /// is done on this path to determine if it is valid.  To determine
653       /// validity of the path, use the isValid method.
654       /// @brief Construct a Path from a string.
PathWithStatus(const char * StrStart,unsigned StrLen)655       explicit PathWithStatus(
656         const char *StrStart,  ///< Pointer to the first character of the path
657         unsigned StrLen        ///< Length of the path.
658       ) : Path(StrStart, StrLen), status(), fsIsValid(false) {}
659 
660       /// Makes a copy of \p that to \p this.
661       /// @returns \p this
662       /// @brief Assignment Operator
663       PathWithStatus &operator=(const PathWithStatus &that) {
664         static_cast<Path&>(*this) = static_cast<const Path&>(that);
665         status = that.status;
666         fsIsValid = that.fsIsValid;
667         return *this;
668       }
669 
670       /// Makes a copy of \p that to \p this.
671       /// @returns \p this
672       /// @brief Assignment Operator
673       PathWithStatus &operator=(const Path &that) {
674         static_cast<Path&>(*this) = static_cast<const Path&>(that);
675         fsIsValid = false;
676         return *this;
677       }
678 
679     /// @}
680     /// @name Methods
681     /// @{
682     public:
683       /// This function returns status information about the file. The type of
684       /// path (file or directory) is updated to reflect the actual contents
685       /// of the file system.
686       /// @returns 0 on failure, with Error explaining why (if non-zero),
687       /// otherwise returns a pointer to a FileStatus structure on success.
688       /// @brief Get file status.
689       const FileStatus *getFileStatus(
690         bool forceUpdate = false, ///< Force an update from the file system
691         std::string *Error = 0    ///< Optional place to return an error msg.
692       ) const;
693 
694     /// @}
695     /// @name Data
696     /// @{
697     private:
698       mutable FileStatus status; ///< Status information.
699       mutable bool fsIsValid;    ///< Whether we've obtained it or not
700 
701     /// @}
702   };
703 
704   /// This enumeration delineates the kinds of files that LLVM knows about.
705   enum LLVMFileType {
706     Unknown_FileType = 0,              ///< Unrecognized file
707     Bitcode_FileType,                  ///< Bitcode file
708     Archive_FileType,                  ///< ar style archive file
709     ELF_Relocatable_FileType,          ///< ELF Relocatable object file
710     ELF_Executable_FileType,           ///< ELF Executable image
711     ELF_SharedObject_FileType,         ///< ELF dynamically linked shared lib
712     ELF_Core_FileType,                 ///< ELF core image
713     Mach_O_Object_FileType,            ///< Mach-O Object file
714     Mach_O_Executable_FileType,        ///< Mach-O Executable
715     Mach_O_FixedVirtualMemorySharedLib_FileType, ///< Mach-O Shared Lib, FVM
716     Mach_O_Core_FileType,              ///< Mach-O Core File
717     Mach_O_PreloadExecutable_FileType, ///< Mach-O Preloaded Executable
718     Mach_O_DynamicallyLinkedSharedLib_FileType, ///< Mach-O dynlinked shared lib
719     Mach_O_DynamicLinker_FileType,     ///< The Mach-O dynamic linker
720     Mach_O_Bundle_FileType,            ///< Mach-O Bundle file
721     Mach_O_DynamicallyLinkedSharedLibStub_FileType, ///< Mach-O Shared lib stub
722     Mach_O_DSYMCompanion_FileType,     ///< Mach-O dSYM companion file
723     COFF_FileType                      ///< COFF object file or lib
724   };
725 
726   /// This utility function allows any memory block to be examined in order
727   /// to determine its file type.
728   LLVMFileType IdentifyFileType(const char*magic, unsigned length);
729 
730   /// This function can be used to copy the file specified by Src to the
731   /// file specified by Dest. If an error occurs, Dest is removed.
732   /// @returns true if an error occurs, false otherwise
733   /// @brief Copy one file to another.
734   bool CopyFile(const Path& Dest, const Path& Src, std::string* ErrMsg);
735 
736   /// This is the OS-specific path separator: a colon on Unix or a semicolon
737   /// on Windows.
738   extern const char PathSeparator;
739 }
740 
741 }
742 
743 #endif
744