1 //===- llvm/System/Path.h - Path Operating System Concept -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the llvm::sys::Path class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SYSTEM_PATH_H
15 #define LLVM_SYSTEM_PATH_H
17 #include "llvm/System/TimeValue.h"
18 #include "llvm/System/IncludeFile.h"
27 /// This structure provides basic file system information about a file. It
28 /// is patterned after the stat(2) Unix operating system call but made
29 /// platform independent and eliminates many of the unix-specific fields.
30 /// However, to support llvm-ar, the mode, user, and group fields are
31 /// retained. These pertain to unix security and may not have a meaningful
32 /// value on non-Unix platforms. However, the fileSize and modTime fields
33 /// should always be applicable on all platforms. The structure is
34 /// filled in by the Path::getFileStatus method.
35 /// @brief File status structure
38 uint64_t fileSize; ///< Size of the file in bytes
39 TimeValue modTime; ///< Time of file's modification
40 uint32_t mode; ///< Mode of the file, if applicable
41 uint32_t user; ///< User ID of owner, if applicable
42 uint32_t group; ///< Group ID of owner, if applicable
43 bool isDir : 1; ///< True if this is a directory.
44 bool isFile : 1; ///< True if this is a file.
46 FileStatus() : fileSize(0), modTime(0,0), mode(0777), user(999),
47 group(999), isDir(false) { }
49 TimeValue getTimestamp() const { return modTime; }
50 size_t getSize() const { return fileSize; }
51 uint32_t getMode() const { return mode; }
52 uint32_t getUser() const { return user; }
53 uint32_t getGroup() const { return group; }
56 /// This class provides an abstraction for the path to a file or directory
57 /// in the operating system's filesystem and provides various basic operations
58 /// on it. Note that this class only represents the name of a path to a file
59 /// or directory which may or may not be valid for a given machine's file
60 /// system. The class is patterned after the java.io.File class with various
61 /// extensions and several omissions (not relevant to LLVM). A Path object
62 /// ensures that the path it encapsulates is syntactically valid for the
63 /// operating system it is running on but does not ensure correctness for
64 /// any particular file system. That is, a syntactically valid path might
65 /// specify path components that do not exist in the file system and using
66 /// such a Path to act on the file system could produce errors. There is one
67 /// invalid Path value which is permitted: the empty path. The class should
68 /// never allow a syntactically invalid non-empty path name to be assigned.
69 /// Empty paths are required in order to indicate an error result in some
70 /// situations. If the path is empty, the isValid operation will return
71 /// false. All operations will fail if isValid is false. Operations that
72 /// change the path will either return false if it would cause a syntactically
73 /// invalid path name (in which case the Path object is left unchanged) or
74 /// throw an std::string exception indicating the error. The methods are
75 /// grouped into four basic categories: Path Accessors (provide information
76 /// about the path without accessing disk), Disk Accessors (provide
77 /// information about the underlying file or directory), Path Mutators
78 /// (change the path information, not the disk), and Disk Mutators (change
79 /// the disk file/directory referenced by the path). The Disk Mutator methods
80 /// all have the word "disk" embedded in their method name to reinforce the
81 /// notion that the operation modifies the file system.
83 /// @brief An abstraction for operating system paths.
85 /// @name Constructors
88 /// Construct a path to the root directory of the file system. The root
89 /// directory is a top level directory above which there are no more
90 /// directories. For example, on UNIX, the root directory is /. On Windows
91 /// it is C:\. Other operating systems may have different notions of
92 /// what the root directory is or none at all. In that case, a consistent
93 /// default root directory will be used.
94 static Path GetRootDirectory();
96 /// Construct a path to a unique temporary directory that is created in
97 /// a "standard" place for the operating system. The directory is
98 /// guaranteed to be created on exit from this function. If the directory
99 /// cannot be created, the function will throw an exception.
100 /// @returns an invalid path (empty) on error
101 /// @param ErrMsg Optional place for an error message if an error occurs
102 /// @brief Constrct a path to an new, unique, existing temporary
104 static Path GetTemporaryDirectory(std::string* ErrMsg);
106 /// Construct a vector of sys::Path that contains the "standard" system
107 /// library paths suitable for linking into programs. This function *must*
108 /// return the value of LLVM_LIB_SEARCH_PATH as the first item in \p Paths
109 /// if that environment variable is set and it references a directory.
110 /// @brief Construct a path to the system library directory
111 static void GetSystemLibraryPaths(std::vector<sys::Path>& Paths);
113 /// Construct a vector of sys::Path that contains the "standard" bytecode
114 /// library paths suitable for linking into an llvm program. This function
115 /// *must* return the value of LLVM_LIB_SEARCH_PATH as well as the value
116 /// of LLVM_LIBDIR. It also must provide the System library paths as
117 /// returned by GetSystemLibraryPaths.
118 /// @see GetSystemLibraryPaths
119 /// @brief Construct a list of directories in which bytecode could be
121 static void GetBytecodeLibraryPaths(std::vector<sys::Path>& Paths);
123 /// Find the path to a library using its short name. Use the system
124 /// dependent library paths to locate the library.
125 /// @brief Find a library.
126 static Path FindLibrary(std::string& short_name);
128 /// Construct a path to the default LLVM configuration directory. The
129 /// implementation must ensure that this is a well-known (same on many
130 /// systems) directory in which llvm configuration files exist. For
131 /// example, on Unix, the /etc/llvm directory has been selected.
132 /// @brief Construct a path to the default LLVM configuration directory
133 static Path GetLLVMDefaultConfigDir();
135 /// Construct a path to the LLVM installed configuration directory. The
136 /// implementation must ensure that this refers to the "etc" directory of
137 /// the LLVM installation. This is the location where configuration files
138 /// will be located for a particular installation of LLVM on a machine.
139 /// @brief Construct a path to the LLVM installed configuration directory
140 static Path GetLLVMConfigDir();
142 /// Construct a path to the current user's home directory. The
143 /// implementation must use an operating system specific mechanism for
144 /// determining the user's home directory. For example, the environment
145 /// variable "HOME" could be used on Unix. If a given operating system
146 /// does not have the concept of a user's home directory, this static
147 /// constructor must provide the same result as GetRootDirectory.
148 /// @brief Construct a path to the current user's "home" directory
149 static Path GetUserHomeDirectory();
151 /// Return the suffix commonly used on file names that contain a shared
152 /// object, shared archive, or dynamic link library. Such files are
153 /// linked at runtime into a process and their code images are shared
154 /// between processes.
155 /// @returns The dynamic link library suffix for the current platform.
156 /// @brief Return the dynamic link library suffix.
157 static std::string GetDLLSuffix();
159 /// This is one of the very few ways in which a path can be constructed
160 /// with a syntactically invalid name. The only *legal* invalid name is an
161 /// empty one. Other invalid names are not permitted. Empty paths are
162 /// provided so that they can be used to indicate null or error results in
163 /// other lib/System functionality.
164 /// @brief Construct an empty (and invalid) path.
167 /// This constructor will accept a std::string as a path but it verifies
168 /// that the path string has a legal syntax for the operating system on
169 /// which it is running. This allows a path to be taken in from outside
170 /// the program. However, if the path is not valid, the Path object will
171 /// be set to an empty string and an exception will be thrown.
172 /// @throws std::string if \p unverified_path is not legal.
173 /// @param unverified_path The path to verify and assign.
174 /// @brief Construct a Path from a string.
175 explicit Path(const std::string& p) : path(p) {}
181 /// Makes a copy of \p that to \p this.
183 /// @brief Assignment Operator
184 Path &operator=(const Path &that) {
189 /// Compares \p this Path with \p that Path for equality.
190 /// @returns true if \p this and \p that refer to the same thing.
191 /// @brief Equality Operator
192 bool operator==(const Path &that) const {
193 return 0 == path.compare(that.path);
196 /// Compares \p this Path with \p that Path for inequality.
197 /// @returns true if \p this and \p that refer to different things.
198 /// @brief Inequality Operator
199 bool operator!=(const Path &that) const {
200 return 0 != path.compare(that.path);
203 /// Determines if \p this Path is less than \p that Path. This is required
204 /// so that Path objects can be placed into ordered collections (e.g.
205 /// std::map). The comparison is done lexicographically as defined by
206 /// the std::string::compare method.
207 /// @returns true if \p this path is lexicographically less than \p that.
208 /// @brief Less Than Operator
209 bool operator<(const Path& that) const {
210 return 0 > path.compare(that.path);
214 /// @name Path Accessors
217 /// This function will use an operating system specific algorithm to
218 /// determine if the current value of \p this is a syntactically valid
219 /// path name for the operating system. The path name does not need to
220 /// exist, validity is simply syntactical. Empty paths are always invalid.
221 /// @returns true iff the path name is syntactically legal for the
222 /// host operating system.
223 /// @brief Determine if a path is syntactically valid or not.
224 bool isValid() const;
226 /// This function determines if the contents of the path name are
227 /// empty. That is, the path has a zero length. This does NOT determine if
228 /// if the file is empty. Use the getSize method for that.
229 /// @returns true iff the path is empty.
230 /// @brief Determines if the path name is empty (invalid).
231 bool isEmpty() const { return path.empty(); }
233 /// This function returns the current contents of the path as a
234 /// std::string. This allows the underlying path string to be manipulated.
235 /// @returns std::string containing the path name.
236 /// @brief Returns the path as a std::string.
237 const std::string &toString() const { return path; }
239 /// This function returns the last component of the path name. The last
240 /// component is the file or directory name occuring after the last
241 /// directory separator. If no directory separator is present, the entire
242 /// path name is returned (i.e. same as toString).
243 /// @returns std::string containing the last component of the path name.
244 /// @brief Returns the last component of the path name.
245 std::string getLast() const;
247 /// This function strips off the path and suffix of the file or directory
248 /// name and returns just the basename. For example /a/foo.bar would cause
249 /// this function to return "foo".
250 /// @returns std::string containing the basename of the path
251 /// @brief Get the base name of the path
252 std::string getBasename() const;
254 /// Obtain a 'C' string for the path name.
255 /// @returns a 'C' string containing the path name.
256 /// @brief Returns the path as a C string.
257 const char *const c_str() const { return path.c_str(); }
260 /// @name Disk Accessors
263 /// This function determines if the path name in this object references
264 /// the root (top level directory) of the file system. The details of what
265 /// is considered the "root" may vary from system to system so this method
266 /// will do the necessary checking.
267 /// @returns true iff the path name references the root directory.
268 /// @brief Determines if the path references the root directory.
269 bool isRootDirectory() const;
271 /// This function opens the file associated with the path name provided by
272 /// the Path object and reads its magic number. If the magic number at the
273 /// start of the file matches \p magic, true is returned. In all other
274 /// cases (file not found, file not accessible, etc.) it returns false.
275 /// @returns true if the magic number of the file matches \p magic.
276 /// @brief Determine if file has a specific magic number
277 bool hasMagicNumber(const std::string& magic) const;
279 /// This function retrieves the first \p len bytes of the file associated
280 /// with \p this. These bytes are returned as the "magic number" in the
281 /// \p Magic parameter.
282 /// @returns true if the Path is a file and the magic number is retrieved,
284 /// @brief Get the file's magic number.
285 bool getMagicNumber(std::string& Magic, unsigned len) const;
287 /// This function determines if the path name in the object references an
288 /// archive file by looking at its magic number.
289 /// @returns true if the file starts with the magic number for an archive
291 /// @brief Determine if the path references an archive file.
292 bool isArchive() const;
294 /// This function determines if the path name in the object references an
295 /// LLVM Bytecode file by looking at its magic number.
296 /// @returns true if the file starts with the magic number for LLVM
298 /// @brief Determine if the path references a bytecode file.
299 bool isBytecodeFile() const;
301 /// This function determines if the path name in the object references a
302 /// native Dynamic Library (shared library, shared object) by looking at
303 /// the file's magic number. The Path object must reference a file, not a
305 /// @return strue if the file starts with the magid number for a native
307 /// @brief Determine if the path reference a dynamic library.
308 bool isDynamicLibrary() const;
310 /// This function determines if the path name references an existing file
311 /// or directory in the file system.
312 /// @returns true if the pathname references an existing file or
314 /// @brief Determines if the path is a file or directory in
318 /// This function determines if the path name references a readable file
319 /// or directory in the file system. This function checks for
320 /// the existence and readability (by the current program) of the file
322 /// @returns true if the pathname references a readable file.
323 /// @brief Determines if the path is a readable file or directory
324 /// in the file system.
325 bool canRead() const;
327 /// This function determines if the path name references a writable file
328 /// or directory in the file system. This function checks for the
329 /// existence and writability (by the current program) of the file or
331 /// @returns true if the pathname references a writable file.
332 /// @brief Determines if the path is a writable file or directory
333 /// in the file system.
334 bool canWrite() const;
336 /// This function determines if the path name references an executable
337 /// file in the file system. This function checks for the existence and
338 /// executability (by the current program) of the file.
339 /// @returns true if the pathname references an executable file.
340 /// @brief Determines if the path is an executable file in the file
342 bool canExecute() const;
344 /// This function builds a list of paths that are the names of the
345 /// files and directories in a directory.
346 /// @returns false if \p this is not a directory, true otherwise
347 /// @throws std::string if the directory cannot be searched
348 /// @brief Build a list of directory's contents.
349 bool getDirectoryContents(std::set<Path> &paths) const;
351 /// This function returns status information about the file. The type of
352 /// path (file or directory) is updated to reflect the actual contents
353 /// of the file system. This returns false on success, or true on error
354 /// and fills in the specified error string if specified.
355 /// @brief Get file status.
356 bool getFileStatus(FileStatus &Status, std::string *Error = 0) const;
359 /// @name Path Mutators
362 /// The path name is cleared and becomes empty. This is an invalid
363 /// path name but is the *only* invalid path name. This is provided
364 /// so that path objects can be used to indicate the lack of a
365 /// valid path being found.
366 /// @brief Make the path empty.
367 void clear() { path.clear(); }
369 /// This method sets the Path object to \p unverified_path. This can fail
370 /// if the \p unverified_path does not pass the syntactic checks of the
371 /// isValid() method. If verification fails, the Path object remains
372 /// unchanged and false is returned. Otherwise true is returned and the
373 /// Path object takes on the path value of \p unverified_path
374 /// @returns true if the path was set, false otherwise.
375 /// @param unverified_path The path to be set in Path object.
376 /// @brief Set a full path from a std::string
377 bool set(const std::string& unverified_path);
379 /// One path component is removed from the Path. If only one component is
380 /// present in the path, the Path object becomes empty. If the Path object
381 /// is empty, no change is made.
382 /// @returns false if the path component could not be removed.
383 /// @brief Removes the last directory component of the Path.
384 bool eraseComponent();
386 /// The \p component is added to the end of the Path if it is a legal
387 /// name for the operating system. A directory separator will be added if
389 /// @returns false if the path component could not be added.
390 /// @brief Appends one path component to the Path.
391 bool appendComponent( const std::string& component );
393 /// A period and the \p suffix are appended to the end of the pathname.
394 /// The precondition for this function is that the Path reference a file
395 /// name (i.e. isFile() returns true). If the Path is not a file, no
396 /// action is taken and the function returns false. If the path would
397 /// become invalid for the host operating system, false is returned.
398 /// @returns false if the suffix could not be added, true if it was.
399 /// @brief Adds a period and the \p suffix to the end of the pathname.
400 bool appendSuffix(const std::string& suffix);
402 /// The suffix of the filename is erased. The suffix begins with and
403 /// includes the last . character in the filename after the last directory
404 /// separator and extends until the end of the name. If no . character is
405 /// after the last directory separator, then the file name is left
406 /// unchanged (i.e. it was already without a suffix) but the function
408 /// @returns false if there was no suffix to remove, true otherwise.
409 /// @brief Remove the suffix from a path name.
412 /// The current Path name is made unique in the file system. Upon return,
413 /// the Path will have been changed to make a unique file in the file
414 /// system or it will not have been changed if the current path name is
416 /// @throws std::string if an unrecoverable error occurs.
417 /// @brief Make the current path name unique in the file system.
418 void makeUnique( bool reuse_current = true );
421 /// @name Disk Mutators
424 /// This method attempts to make the file referenced by the Path object
425 /// available for reading so that the canRead() method will return true.
426 /// @brief Make the file readable;
427 void makeReadableOnDisk();
429 /// This method attempts to make the file referenced by the Path object
430 /// available for writing so that the canWrite() method will return true.
431 /// @brief Make the file writable;
432 void makeWriteableOnDisk();
434 /// This method attempts to make the file referenced by the Path object
435 /// available for execution so that the canExecute() method will return
437 /// @brief Make the file readable;
438 void makeExecutableOnDisk();
440 /// This method allows the last modified time stamp and permission bits
441 /// to be set on the disk object referenced by the Path.
442 /// @throws std::string if an error occurs.
443 /// @returns true on error.
444 /// @brief Set the status information.
445 bool setStatusInfoOnDisk(const FileStatus &SI,
446 std::string *ErrStr = 0) const;
448 /// This method attempts to create a directory in the file system with the
449 /// same name as the Path object. The \p create_parents parameter controls
450 /// whether intermediate directories are created or not. if \p
451 /// create_parents is true, then an attempt will be made to create all
452 /// intermediate directories, as needed. If \p create_parents is false,
453 /// then only the final directory component of the Path name will be
454 /// created. The created directory will have no entries.
455 /// @returns false if the Path does not reference a directory, true
457 /// @param create_parents Determines whether non-existent directory
458 /// components other than the last one (the "parents") are created or not.
459 /// @throws std::string if an error occurs.
460 /// @brief Create the directory this Path refers to.
461 bool createDirectoryOnDisk( bool create_parents = false );
463 /// This method attempts to create a file in the file system with the same
464 /// name as the Path object. The intermediate directories must all exist
465 /// at the time this method is called. Use createDirectoriesOnDisk to
466 /// accomplish that. The created file will be empty upon return from this
468 /// @returns false if the Path does not reference a file, true otherwise.
469 /// @throws std::string if an error occurs.
470 /// @brief Create the file this Path refers to.
471 bool createFileOnDisk();
473 /// This is like createFile except that it creates a temporary file. A
474 /// unique temporary file name is generated based on the contents of
475 /// \p this before the call. The new name is assigned to \p this and the
476 /// file is created. Note that this will both change the Path object
477 /// *and* create the corresponding file. This function will ensure that
478 /// the newly generated temporary file name is unique in the file system.
479 /// @param reuse_current When set to true, this parameter indicates that
480 /// if the current file name does not exist then it will be used without
482 /// @returns true if successful, false if the file couldn't be created.
483 /// @throws std::string if there is a hard error creating the temp file
485 /// @brief Create a unique temporary file
486 bool createTemporaryFileOnDisk(bool reuse_current = false);
488 /// This method renames the file referenced by \p this as \p newName. The
489 /// file referenced by \p this must exist. The file referenced by
490 /// \p newName does not need to exist.
492 /// @throws std::string if there is an file system error.
493 /// @brief Rename one file as another.
494 bool renamePathOnDisk(const Path& newName);
496 /// This method attempts to destroy the file or directory named by the
497 /// last component of the Path. If the Path refers to a directory and the
498 /// \p destroy_contents is false, an attempt will be made to remove just
499 /// the directory (the final Path component). If \p destroy_contents is
500 /// true, an attempt will be made to remove the entire contents of the
501 /// directory, recursively. If the Path refers to a file, the
502 /// \p destroy_contents parameter is ignored.
503 /// @param destroy_contents Indicates whether the contents of a destroyed
504 /// directory should also be destroyed (recursively).
505 /// @returns false if the file/directory was destroyed, true on error.
506 /// @brief Removes the file or directory from the filesystem.
507 bool eraseFromDisk(bool destroy_contents = false,
508 std::string *Err = 0) const;
513 mutable std::string path; ///< Storage for the path name.
518 /// This enumeration delineates the kinds of files that LLVM knows about.
520 UnknownFileType = 0, ///< Unrecognized file
521 BytecodeFileType = 1, ///< Uncompressed bytecode file
522 CompressedBytecodeFileType = 2, ///< Compressed bytecode file
523 ArchiveFileType = 3 ///< ar style archive file
526 /// This utility function allows any memory block to be examined in order
527 /// to determine its file type.
528 LLVMFileType IdentifyFileType(const char*magic, unsigned length);
530 /// This function can be used to copy the file specified by Src to the
531 /// file specified by Dest. If an error occurs, Dest is removed.
532 /// @throws std::string if an error opening or writing the files occurs.
533 /// @brief Copy one file to another.
534 void CopyFile(const Path& Dest, const Path& Src);
537 std::ostream& operator<<(std::ostream& strm, const sys::Path& aPath);
541 FORCE_DEFINING_FILE_TO_BE_LINKED(SystemPath)