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 uint64_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 = 0);
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. No checking is
168 /// done on this path to determine if it is valid. To determine validity
169 /// of the path, use the isValid method.
170 /// @param p The path to assign.
171 /// @brief Construct a Path from a string.
172 explicit Path(const std::string& p) : path(p) {}
178 /// Makes a copy of \p that to \p this.
180 /// @brief Assignment Operator
181 Path &operator=(const Path &that) {
186 /// Compares \p this Path with \p that Path for equality.
187 /// @returns true if \p this and \p that refer to the same thing.
188 /// @brief Equality Operator
189 bool operator==(const Path &that) const {
190 return 0 == path.compare(that.path);
193 /// Compares \p this Path with \p that Path for inequality.
194 /// @returns true if \p this and \p that refer to different things.
195 /// @brief Inequality Operator
196 bool operator!=(const Path &that) const {
197 return 0 != path.compare(that.path);
200 /// Determines if \p this Path is less than \p that Path. This is required
201 /// so that Path objects can be placed into ordered collections (e.g.
202 /// std::map). The comparison is done lexicographically as defined by
203 /// the std::string::compare method.
204 /// @returns true if \p this path is lexicographically less than \p that.
205 /// @brief Less Than Operator
206 bool operator<(const Path& that) const {
207 return 0 > path.compare(that.path);
211 /// @name Path Accessors
214 /// This function will use an operating system specific algorithm to
215 /// determine if the current value of \p this is a syntactically valid
216 /// path name for the operating system. The path name does not need to
217 /// exist, validity is simply syntactical. Empty paths are always invalid.
218 /// @returns true iff the path name is syntactically legal for the
219 /// host operating system.
220 /// @brief Determine if a path is syntactically valid or not.
221 bool isValid() const;
223 /// This function determines if the contents of the path name are
224 /// empty. That is, the path has a zero length. This does NOT determine if
225 /// if the file is empty. Use the getSize method for that.
226 /// @returns true iff the path is empty.
227 /// @brief Determines if the path name is empty (invalid).
228 bool isEmpty() const { return path.empty(); }
230 /// This function returns the current contents of the path as a
231 /// std::string. This allows the underlying path string to be manipulated.
232 /// @returns std::string containing the path name.
233 /// @brief Returns the path as a std::string.
234 const std::string &toString() const { return path; }
236 /// This function returns the last component of the path name. The last
237 /// component is the file or directory name occuring after the last
238 /// directory separator. If no directory separator is present, the entire
239 /// path name is returned (i.e. same as toString).
240 /// @returns std::string containing the last component of the path name.
241 /// @brief Returns the last component of the path name.
242 std::string getLast() const;
244 /// This function strips off the path and suffix of the file or directory
245 /// name and returns just the basename. For example /a/foo.bar would cause
246 /// this function to return "foo".
247 /// @returns std::string containing the basename of the path
248 /// @brief Get the base name of the path
249 std::string getBasename() const;
251 /// Obtain a 'C' string for the path name.
252 /// @returns a 'C' string containing the path name.
253 /// @brief Returns the path as a C string.
254 const char *const c_str() const { return path.c_str(); }
257 /// @name Disk Accessors
260 /// This function determines if the path name in this object references
261 /// the root (top level directory) of the file system. The details of what
262 /// is considered the "root" may vary from system to system so this method
263 /// will do the necessary checking.
264 /// @returns true iff the path name references the root directory.
265 /// @brief Determines if the path references the root directory.
266 bool isRootDirectory() const;
268 /// This function opens the file associated with the path name provided by
269 /// the Path object and reads its magic number. If the magic number at the
270 /// start of the file matches \p magic, true is returned. In all other
271 /// cases (file not found, file not accessible, etc.) it returns false.
272 /// @returns true if the magic number of the file matches \p magic.
273 /// @brief Determine if file has a specific magic number
274 bool hasMagicNumber(const std::string& magic) const;
276 /// This function retrieves the first \p len bytes of the file associated
277 /// with \p this. These bytes are returned as the "magic number" in the
278 /// \p Magic parameter.
279 /// @returns true if the Path is a file and the magic number is retrieved,
281 /// @brief Get the file's magic number.
282 bool getMagicNumber(std::string& Magic, unsigned len) const;
284 /// This function determines if the path name in the object references an
285 /// archive file by looking at its magic number.
286 /// @returns true if the file starts with the magic number for an archive
288 /// @brief Determine if the path references an archive file.
289 bool isArchive() const;
291 /// This function determines if the path name in the object references an
292 /// LLVM Bytecode file by looking at its magic number.
293 /// @returns true if the file starts with the magic number for LLVM
295 /// @brief Determine if the path references a bytecode file.
296 bool isBytecodeFile() const;
298 /// This function determines if the path name in the object references a
299 /// native Dynamic Library (shared library, shared object) by looking at
300 /// the file's magic number. The Path object must reference a file, not a
302 /// @return strue if the file starts with the magid number for a native
304 /// @brief Determine if the path reference a dynamic library.
305 bool isDynamicLibrary() const;
307 /// This function determines if the path name references an existing file
308 /// or directory in the file system.
309 /// @returns true if the pathname references an existing file or
311 /// @brief Determines if the path is a file or directory in
315 /// This function determines if the path name references a readable file
316 /// or directory in the file system. This function checks for
317 /// the existence and readability (by the current program) of the file
319 /// @returns true if the pathname references a readable file.
320 /// @brief Determines if the path is a readable file or directory
321 /// in the file system.
322 bool canRead() const;
324 /// This function determines if the path name references a writable file
325 /// or directory in the file system. This function checks for the
326 /// existence and writability (by the current program) of the file or
328 /// @returns true if the pathname references a writable file.
329 /// @brief Determines if the path is a writable file or directory
330 /// in the file system.
331 bool canWrite() const;
333 /// This function determines if the path name references an executable
334 /// file in the file system. This function checks for the existence and
335 /// executability (by the current program) of the file.
336 /// @returns true if the pathname references an executable file.
337 /// @brief Determines if the path is an executable file in the file
339 bool canExecute() const;
341 /// This function builds a list of paths that are the names of the
342 /// files and directories in a directory.
343 /// @returns true if an error occurs, true otherwise
344 /// @brief Build a list of directory's contents.
345 bool getDirectoryContents(
346 std::set<Path> &paths, ///< The resulting list of file & directory names
347 std::string* ErrMsg ///< Optional place to return an error message.
350 /// This function returns status information about the file. The type of
351 /// path (file or directory) is updated to reflect the actual contents
352 /// of the file system. This returns false on success, or true on error
353 /// and fills in the specified error string if specified.
354 /// @brief Get file status.
355 bool getFileStatus(FileStatus &Status, std::string *Error = 0) const;
358 /// @name Path Mutators
361 /// The path name is cleared and becomes empty. This is an invalid
362 /// path name but is the *only* invalid path name. This is provided
363 /// so that path objects can be used to indicate the lack of a
364 /// valid path being found.
365 /// @brief Make the path empty.
366 void clear() { path.clear(); }
368 /// This method sets the Path object to \p unverified_path. This can fail
369 /// if the \p unverified_path does not pass the syntactic checks of the
370 /// isValid() method. If verification fails, the Path object remains
371 /// unchanged and false is returned. Otherwise true is returned and the
372 /// Path object takes on the path value of \p unverified_path
373 /// @returns true if the path was set, false otherwise.
374 /// @param unverified_path The path to be set in Path object.
375 /// @brief Set a full path from a std::string
376 bool set(const std::string& unverified_path);
378 /// One path component is removed from the Path. If only one component is
379 /// present in the path, the Path object becomes empty. If the Path object
380 /// is empty, no change is made.
381 /// @returns false if the path component could not be removed.
382 /// @brief Removes the last directory component of the Path.
383 bool eraseComponent();
385 /// The \p component is added to the end of the Path if it is a legal
386 /// name for the operating system. A directory separator will be added if
388 /// @returns false if the path component could not be added.
389 /// @brief Appends one path component to the Path.
390 bool appendComponent( const std::string& component );
392 /// A period and the \p suffix are appended to the end of the pathname.
393 /// The precondition for this function is that the Path reference a file
394 /// name (i.e. isFile() returns true). If the Path is not a file, no
395 /// action is taken and the function returns false. If the path would
396 /// become invalid for the host operating system, false is returned.
397 /// @returns false if the suffix could not be added, true if it was.
398 /// @brief Adds a period and the \p suffix to the end of the pathname.
399 bool appendSuffix(const std::string& suffix);
401 /// The suffix of the filename is erased. The suffix begins with and
402 /// includes the last . character in the filename after the last directory
403 /// separator and extends until the end of the name. If no . character is
404 /// after the last directory separator, then the file name is left
405 /// unchanged (i.e. it was already without a suffix) but the function
407 /// @returns false if there was no suffix to remove, true otherwise.
408 /// @brief Remove the suffix from a path name.
411 /// The current Path name is made unique in the file system. Upon return,
412 /// the Path will have been changed to make a unique file in the file
413 /// system or it will not have been changed if the current path name is
415 /// @throws std::string if an unrecoverable error occurs.
416 /// @brief Make the current path name unique in the file system.
417 bool makeUnique( bool reuse_current /*= true*/, std::string* ErrMsg );
420 /// @name Disk Mutators
423 /// This method attempts to make the file referenced by the Path object
424 /// available for reading so that the canRead() method will return true.
425 /// @brief Make the file readable;
426 bool makeReadableOnDisk(std::string* ErrMsg = 0);
428 /// This method attempts to make the file referenced by the Path object
429 /// available for writing so that the canWrite() method will return true.
430 /// @brief Make the file writable;
431 bool makeWriteableOnDisk(std::string* ErrMsg = 0);
433 /// This method attempts to make the file referenced by the Path object
434 /// available for execution so that the canExecute() method will return
436 /// @brief Make the file readable;
437 bool makeExecutableOnDisk(std::string* ErrMsg = 0);
439 /// This method allows the last modified time stamp and permission bits
440 /// to be set on the disk object referenced by the Path.
441 /// @throws std::string if an error occurs.
442 /// @returns true on error.
443 /// @brief Set the status information.
444 bool setStatusInfoOnDisk(const FileStatus &SI,
445 std::string *ErrStr = 0) const;
447 /// This method attempts to create a directory in the file system with the
448 /// same name as the Path object. The \p create_parents parameter controls
449 /// whether intermediate directories are created or not. if \p
450 /// create_parents is true, then an attempt will be made to create all
451 /// intermediate directories, as needed. If \p create_parents is false,
452 /// then only the final directory component of the Path name will be
453 /// created. The created directory will have no entries.
454 /// @returns true if the directory could not be created, false otherwise
455 /// @brief Create the directory this Path refers to.
456 bool createDirectoryOnDisk(
457 bool create_parents = false, ///< Determines whether non-existent
458 ///< directory components other than the last one (the "parents")
459 ///< are created or not.
460 std::string* ErrMsg = 0 ///< Optional place to put error messages.
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 true if the file could not be created, false otherwise.
469 /// @brief Create the file this Path refers to.
470 bool createFileOnDisk(
471 std::string* ErrMsg = 0 ///< Optional place to put error messages.
474 /// This is like createFile except that it creates a temporary file. A
475 /// unique temporary file name is generated based on the contents of
476 /// \p this before the call. The new name is assigned to \p this and the
477 /// file is created. Note that this will both change the Path object
478 /// *and* create the corresponding file. This function will ensure that
479 /// the newly generated temporary file name is unique in the file system.
480 /// @returns true if the file couldn't be created, false otherwise.
481 /// @brief Create a unique temporary file
482 bool createTemporaryFileOnDisk(
483 bool reuse_current = false, ///< When set to true, this parameter
484 ///< indicates that if the current file name does not exist then
485 ///< it will be used without modification.
486 std::string* ErrMsg = 0 ///< Optional place to put error messages
489 /// This method renames the file referenced by \p this as \p newName. The
490 /// file referenced by \p this must exist. The file referenced by
491 /// \p newName does not need to exist.
492 /// @returns true on error, false otherwise
493 /// @brief Rename one file as another.
494 bool renamePathOnDisk(const Path& newName, std::string* ErrMsg);
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 /// @returns true if an error occurs, false otherwise
533 /// @brief Copy one file to another.
534 bool CopyFile(const Path& Dest, const Path& Src, std::string* ErrMsg);
537 std::ostream& operator<<(std::ostream& strm, const sys::Path& aPath);
541 FORCE_DEFINING_FILE_TO_BE_LINKED(SystemPath)