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"
26 /// This class provides an abstraction for the path to a file or directory
27 /// in the operating system's filesystem and provides various basic operations
28 /// on it. Note that this class only represents the name of a path to a file
29 /// or directory which may or may not be valid for a given machine's file
30 /// system. The class is patterned after the java.io.File class with various
31 /// extensions and several omissions (not relevant to LLVM). A Path object
32 /// ensures that the path it encapsulates is syntactically valid for the
33 /// operating system it is running on but does not ensure correctness for
34 /// any particular file system. That is, a syntactically valid path might
35 /// specify path components that do not exist in the file system and using
36 /// such a Path to act on the file system could produce errors. There is one
37 /// invalid Path value which is permitted: the empty path. The class should
38 /// never allow a syntactically invalid non-empty path name to be assigned.
39 /// Empty paths are required in order to indicate an error result in some
40 /// situations. If the path is empty, the isValid operation will return
41 /// false. All operations will fail if isValid is false. Operations that
42 /// change the path will either return false if it would cause a syntactically
43 /// invalid path name (in which case the Path object is left unchanged) or
44 /// throw an std::string exception indicating the error. The methods are
45 /// grouped into four basic categories: Path Accessors (provide information
46 /// about the path without accessing disk), Disk Accessors (provide
47 /// information about the underlying file or directory), Path Mutators
48 /// (change the path information, not the disk), and Disk Mutators (change
49 /// the disk file/directory referenced by the path). The Disk Mutator methods
50 /// all have the word "disk" embedded in their method name to reinforce the
51 /// notion that the operation modifies the file system.
53 /// @brief An abstraction for operating system paths.
58 /// This structure provides basic file system information about a file. It
59 /// is patterned after the stat(2) Unix operating system call but made
60 /// platform independent and eliminates many of the unix-specific fields.
61 /// However, to support llvm-ar, the mode, user, and group fields are
62 /// retained. These pertain to unix security and may not have a meaningful
63 /// value on non-Unix platforms. However, the fileSize and modTime fields
64 /// should always be applicabe on all platforms. The structure is
65 /// filled in by the getStatusInfo method.
66 /// @brief File status structure
68 StatusInfo() : fileSize(0), modTime(0,0), mode(0777), user(999),
69 group(999), isDir(false) { }
70 size_t fileSize; ///< Size of the file in bytes
71 TimeValue modTime; ///< Time of file's modification
72 uint32_t mode; ///< Mode of the file, if applicable
73 uint32_t user; ///< User ID of owner, if applicable
74 uint32_t group; ///< Group ID of owner, if applicable
75 bool isDir; ///< True if this is a directory.
79 /// @name Constructors
82 /// Construct a path to the root directory of the file system. The root
83 /// directory is a top level directory above which there are no more
84 /// directories. For example, on UNIX, the root directory is /. On Windows
85 /// it is C:\. Other operating systems may have different notions of
86 /// what the root directory is or none at all. In that case, a consistent
87 /// default root directory will be used.
88 static Path GetRootDirectory();
90 /// Construct a path to a unique temporary directory that is created in
91 /// a "standard" place for the operating system. The directory is
92 /// guaranteed to be created on exit from this function. If the directory
93 /// cannot be created, the function will throw an exception.
94 /// @throws std::string indicating why the directory could not be created.
95 /// @brief Constrct a path to an new, unique, existing temporary
97 static Path GetTemporaryDirectory();
99 /// Construct a vector of sys::Path that contains the "standard" system
100 /// library paths suitable for linking into programs. This function *must*
101 /// return the value of LLVM_LIB_SEARCH_PATH as the first item in \p Paths
102 /// if that environment variable is set and it references a directory.
103 /// @brief Construct a path to the system library directory
104 static void GetSystemLibraryPaths(std::vector<sys::Path>& Paths);
106 /// Construct a vector of sys::Path that contains the "standard" bytecode
107 /// library paths suitable for linking into an llvm program. This function
108 /// *must* return the value of LLVM_LIB_SEARCH_PATH as well as the value
109 /// of LLVM_LIBDIR. It also must provide the System library paths as
110 /// returned by GetSystemLibraryPaths.
111 /// @see GetSystemLibraryPaths
112 /// @brief Construct a list of directories in which bytecode could be
114 static void GetBytecodeLibraryPaths(std::vector<sys::Path>& Paths);
116 /// Find the path to a library using its short name. Use the system
117 /// dependent library paths to locate the library.
118 /// @brief Find a library.
119 static Path FindLibrary(std::string& short_name);
121 /// Construct a path to the default LLVM configuration directory. The
122 /// implementation must ensure that this is a well-known (same on many
123 /// systems) directory in which llvm configuration files exist. For
124 /// example, on Unix, the /etc/llvm directory has been selected.
125 /// @brief Construct a path to the default LLVM configuration directory
126 static Path GetLLVMDefaultConfigDir();
128 /// Construct a path to the LLVM installed configuration directory. The
129 /// implementation must ensure that this refers to the "etc" directory of
130 /// the LLVM installation. This is the location where configuration files
131 /// will be located for a particular installation of LLVM on a machine.
132 /// @brief Construct a path to the LLVM installed configuration directory
133 static Path GetLLVMConfigDir();
135 /// Construct a path to the current user's home directory. The
136 /// implementation must use an operating system specific mechanism for
137 /// determining the user's home directory. For example, the environment
138 /// variable "HOME" could be used on Unix. If a given operating system
139 /// does not have the concept of a user's home directory, this static
140 /// constructor must provide the same result as GetRootDirectory.
141 /// @brief Construct a path to the current user's "home" directory
142 static Path GetUserHomeDirectory();
144 /// Return the suffix commonly used on file names that contain a shared
145 /// object, shared archive, or dynamic link library. Such files are
146 /// linked at runtime into a process and their code images are shared
147 /// between processes.
148 /// @returns The dynamic link library suffix for the current platform.
149 /// @brief Return the dynamic link library suffix.
150 static std::string GetDLLSuffix();
152 /// This is one of the very few ways in which a path can be constructed
153 /// with a syntactically invalid name. The only *legal* invalid name is an
154 /// empty one. Other invalid names are not permitted. Empty paths are
155 /// provided so that they can be used to indicate null or error results in
156 /// other lib/System functionality.
157 /// @brief Construct an empty (and invalid) path.
160 /// This constructor will accept a std::string as a path but it verifies
161 /// that the path string has a legal syntax for the operating system on
162 /// which it is running. This allows a path to be taken in from outside
163 /// the program. However, if the path is not valid, the Path object will
164 /// be set to an empty string and an exception will be thrown.
165 /// @throws std::string if \p unverified_path is not legal.
166 /// @param unverified_path The path to verify and assign.
167 /// @brief Construct a Path from a string.
168 explicit Path(const std::string& unverified_path);
174 /// Makes a copy of \p that to \p this.
176 /// @brief Assignment Operator
177 Path & operator = ( const Path & that ) {
182 /// Compares \p this Path with \p that Path for equality.
183 /// @returns true if \p this and \p that refer to the same thing.
184 /// @brief Equality Operator
185 bool operator == (const Path& that) const {
186 return 0 == path.compare(that.path) ;
189 /// Compares \p this Path with \p that Path for inequality.
190 /// @returns true if \p this and \p that refer to different things.
191 /// @brief Inequality Operator
192 bool operator !=( const Path & that ) const {
193 return 0 != path.compare( that.path );
196 /// Determines if \p this Path is less than \p that Path. This is required
197 /// so that Path objects can be placed into ordered collections (e.g.
198 /// std::map). The comparison is done lexicographically as defined by
199 /// the std::string::compare method.
200 /// @returns true if \p this path is lexicographically less than \p that.
201 /// @brief Less Than Operator
202 bool operator< (const Path& that) const {
203 return 0 > path.compare( that.path );
207 /// @name Path Accessors
210 /// This function will use an operating system specific algorithm to
211 /// determine if the current value of \p this is a syntactically valid
212 /// path name for the operating system. The path name does not need to
213 /// exist, validity is simply syntactical. Empty paths are always invalid.
214 /// @returns true iff the path name is syntactically legal for the
215 /// host operating system.
216 /// @brief Determine if a path is syntactically valid or not.
217 bool isValid() const;
219 /// This function determines if the contents of the path name are
220 /// empty. That is, the path has a zero length. This does NOT determine if
221 /// if the file is empty. Use the getSize method for that.
222 /// @returns true iff the path is empty.
223 /// @brief Determines if the path name is empty (invalid).
224 bool isEmpty() const { return path.empty(); }
226 /// This function returns the current contents of the path as a
227 /// std::string. This allows the underlying path string to be manipulated.
228 /// @returns std::string containing the path name.
229 /// @brief Returns the path as a std::string.
230 const std::string& toString() const { return path; }
232 /// This function returns the last component of the path name. The last
233 /// component is the file or directory name occuring after the last
234 /// directory separator. If no directory separator is present, the entire
235 /// path name is returned (i.e. same as toString).
236 /// @returns std::string containing the last component of the path name.
237 /// @brief Returns the last component of the path name.
238 std::string getLast() const;
240 /// This function strips off the path and suffix of the file or directory
241 /// name and returns just the basename. For example /a/foo.bar would cause
242 /// this function to return "foo".
243 /// @returns std::string containing the basename of the path
244 /// @brief Get the base name of the path
245 std::string getBasename() const;
247 /// Obtain a 'C' string for the path name.
248 /// @returns a 'C' string containing the path name.
249 /// @brief Returns the path as a C string.
250 const char* const c_str() const { return path.c_str(); }
253 /// @name Disk Accessors
256 /// This function determines if the object referenced by this path is
257 /// a file or not. This function accesses the underlying file system to
258 /// determine the type of entity referenced by the path.
259 /// @returns true if this path name references a file.
260 /// @brief Determines if the path name references a file.
263 /// This function determines if the object referenced by this path is a
264 /// directory or not. This function accesses the underlying file system to
265 /// determine the type of entity referenced by the path.
266 /// @returns true if the path name references a directory
267 /// @brief Determines if the path name references a directory.
268 bool isDirectory() const;
270 /// This function determines if the path refers to a hidden file. The
271 /// notion of hidden files is defined by the underlying system. The
272 /// system may not support hidden files in which case this function always
273 /// returns false on such systems. Hidden files have the "hidden"
274 /// attribute set on Win32. On Unix, hidden files start with a period.
275 /// @brief Determines if the path name references a hidden file.
276 bool isHidden() const;
278 /// This function determines if the path name in this object references
279 /// the root (top level directory) of the file system. The details of what
280 /// is considered the "root" may vary from system to system so this method
281 /// will do the necessary checking.
282 /// @returns true iff the path name references the root directory.
283 /// @brief Determines if the path references the root directory.
284 bool isRootDirectory() const;
286 /// This function opens the file associated with the path name provided by
287 /// the Path object and reads its magic number. If the magic number at the
288 /// start of the file matches \p magic, true is returned. In all other
289 /// cases (file not found, file not accessible, etc.) it returns false.
290 /// @returns true if the magic number of the file matches \p magic.
291 /// @brief Determine if file has a specific magic number
292 bool hasMagicNumber(const std::string& magic) const;
294 /// This function retrieves the first \p len bytes of the file associated
295 /// with \p this. These bytes are returned as the "magic number" in the
296 /// \p Magic parameter.
297 /// @returns true if the Path is a file and the magic number is retrieved,
299 /// @brief Get the file's magic number.
300 bool getMagicNumber(std::string& Magic, unsigned len) const;
302 /// This function determines if the path name in the object references an
303 /// archive file by looking at its magic number.
304 /// @returns true if the file starts with the magic number for an archive
306 /// @brief Determine if the path references an archive file.
307 bool isArchive() const;
309 /// This function determines if the path name in the object references an
310 /// LLVM Bytecode file by looking at its magic number.
311 /// @returns true if the file starts with the magic number for LLVM
313 /// @brief Determine if the path references a bytecode file.
314 bool isBytecodeFile() const;
316 /// This function determines if the path name in the object references a
317 /// native Dynamic Library (shared library, shared object) by looking at
318 /// the file's magic number. The Path object must reference a file, not a
320 /// @return strue if the file starts with the magid number for a native
322 /// @brief Determine if the path reference a dynamic library.
323 bool isDynamicLibrary() const;
325 /// This function determines if the path name references an existing file
326 /// or directory in the file system.
327 /// @returns true if the pathname references an existing file or
329 /// @brief Determines if the path is a file or directory in
333 /// This function determines if the path name references a readable file
334 /// or directory in the file system. This function checks for
335 /// the existence and readability (by the current program) of the file
337 /// @returns true if the pathname references a readable file.
338 /// @brief Determines if the path is a readable file or directory
339 /// in the file system.
340 bool canRead() const;
342 /// This function determines if the path name references a writable file
343 /// or directory in the file system. This function checks for the
344 /// existence and writability (by the current program) of the file or
346 /// @returns true if the pathname references a writable file.
347 /// @brief Determines if the path is a writable file or directory
348 /// in the file system.
349 bool canWrite() const;
351 /// This function determines if the path name references an executable
352 /// file in the file system. This function checks for the existence and
353 /// executability (by the current program) of the file.
354 /// @returns true if the pathname references an executable file.
355 /// @brief Determines if the path is an executable file in the file
357 bool canExecute() const;
359 /// This function builds a list of paths that are the names of the
360 /// files and directories in a directory.
361 /// @returns false if \p this is not a directory, true otherwise
362 /// @throws std::string if the directory cannot be searched
363 /// @brief Build a list of directory's contents.
364 bool getDirectoryContents(std::set<Path>& paths) const;
366 /// This function returns status information about the file. The type of
367 /// path (file or directory) is updated to reflect the actual contents
368 /// of the file system. If the file does not exist, false is returned.
369 /// For other (hard I/O) errors, a std::string is thrown indicating the
371 /// @throws std::string if an error occurs.
372 /// @brief Get file status.
373 void getStatusInfo(StatusInfo& info) const;
375 /// This function returns the last modified time stamp for the file
376 /// referenced by this path. The Path may reference a file or a directory.
377 /// If the file does not exist, a ZeroTime timestamp is returned.
378 /// @returns last modified timestamp of the file/directory or ZeroTime
379 /// @brief Get file timestamp.
380 inline TimeValue getTimestamp() const {
381 StatusInfo info; getStatusInfo(info); return info.modTime;
384 /// This function returns the size of the file referenced by this path.
385 /// @brief Get file size.
386 inline size_t getSize() const {
387 StatusInfo info; getStatusInfo(info); return info.fileSize;
391 /// @name Path Mutators
394 /// The path name is cleared and becomes empty. This is an invalid
395 /// path name but is the *only* invalid path name. This is provided
396 /// so that path objects can be used to indicate the lack of a
397 /// valid path being found.
398 /// @brief Make the path empty.
399 void clear() { path.clear(); }
401 /// This method sets the Path object to \p unverified_path. This can fail
402 /// if the \p unverified_path does not pass the syntactic checks of the
403 /// isValid() method. If verification fails, the Path object remains
404 /// unchanged and false is returned. Otherwise true is returned and the
405 /// Path object takes on the path value of \p unverified_path
406 /// @returns true if the path was set, false otherwise.
407 /// @param unverified_path The path to be set in Path object.
408 /// @brief Set a full path from a std::string
409 bool set(const std::string& unverified_path);
411 /// One path component is removed from the Path. If only one component is
412 /// present in the path, the Path object becomes empty. If the Path object
413 /// is empty, no change is made.
414 /// @returns false if the path component could not be removed.
415 /// @brief Removes the last directory component of the Path.
416 bool eraseComponent();
418 /// The \p component is added to the end of the Path if it is a legal
419 /// name for the operating system. A directory separator will be added if
421 /// @returns false if the path component could not be added.
422 /// @brief Appends one path component to the Path.
423 bool appendComponent( const std::string& component );
425 /// A period and the \p suffix are appended to the end of the pathname.
426 /// The precondition for this function is that the Path reference a file
427 /// name (i.e. isFile() returns true). If the Path is not a file, no
428 /// action is taken and the function returns false. If the path would
429 /// become invalid for the host operating system, false is returned.
430 /// @returns false if the suffix could not be added, true if it was.
431 /// @brief Adds a period and the \p suffix to the end of the pathname.
432 bool appendSuffix(const std::string& suffix);
434 /// The suffix of the filename is erased. The suffix begins with and
435 /// includes the last . character in the filename after the last directory
436 /// separator and extends until the end of the name. If no . character is
437 /// after the last directory separator, then the file name is left
438 /// unchanged (i.e. it was already without a suffix) but the function
440 /// @returns false if there was no suffix to remove, true otherwise.
441 /// @brief Remove the suffix from a path name.
444 /// The current Path name is made unique in the file system. Upon return,
445 /// the Path will have been changed to make a unique file in the file
446 /// system or it will not have been changed if the current path name is
448 /// @throws std::string if an unrecoverable error occurs.
449 /// @brief Make the current path name unique in the file system.
450 void makeUnique( bool reuse_current = true );
453 /// @name Disk Mutators
456 /// This method attempts to make the file referenced by the Path object
457 /// available for reading so that the canRead() method will return true.
458 /// @brief Make the file readable;
459 void makeReadableOnDisk();
461 /// This method attempts to make the file referenced by the Path object
462 /// available for writing so that the canWrite() method will return true.
463 /// @brief Make the file writable;
464 void makeWriteableOnDisk();
466 /// This method attempts to make the file referenced by the Path object
467 /// available for execution so that the canExecute() method will return
469 /// @brief Make the file readable;
470 void makeExecutableOnDisk();
472 /// This method allows the last modified time stamp and permission bits
473 /// to be set on the disk object referenced by the Path.
474 /// @throws std::string if an error occurs.
476 /// @brief Set the status information.
477 bool setStatusInfoOnDisk(const StatusInfo& si) const;
479 /// This method attempts to create a directory in the file system with the
480 /// same name as the Path object. The \p create_parents parameter controls
481 /// whether intermediate directories are created or not. if \p
482 /// create_parents is true, then an attempt will be made to create all
483 /// intermediate directories, as needed. If \p create_parents is false,
484 /// then only the final directory component of the Path name will be
485 /// created. The created directory will have no entries.
486 /// @returns false if the Path does not reference a directory, true
488 /// @param create_parents Determines whether non-existent directory
489 /// components other than the last one (the "parents") are created or not.
490 /// @throws std::string if an error occurs.
491 /// @brief Create the directory this Path refers to.
492 bool createDirectoryOnDisk( bool create_parents = false );
494 /// This method attempts to create a file in the file system with the same
495 /// name as the Path object. The intermediate directories must all exist
496 /// at the time this method is called. Use createDirectoriesOnDisk to
497 /// accomplish that. The created file will be empty upon return from this
499 /// @returns false if the Path does not reference a file, true otherwise.
500 /// @throws std::string if an error occurs.
501 /// @brief Create the file this Path refers to.
502 bool createFileOnDisk();
504 /// This is like createFile except that it creates a temporary file. A
505 /// unique temporary file name is generated based on the contents of
506 /// \p this before the call. The new name is assigned to \p this and the
507 /// file is created. Note that this will both change the Path object
508 /// *and* create the corresponding file. This function will ensure that
509 /// the newly generated temporary file name is unique in the file system.
510 /// @param reuse_current When set to true, this parameter indicates that
511 /// if the current file name does not exist then it will be used without
513 /// @returns true if successful, false if the file couldn't be created.
514 /// @throws std::string if there is a hard error creating the temp file
516 /// @brief Create a unique temporary file
517 bool createTemporaryFileOnDisk(bool reuse_current = false);
519 /// This method renames the file referenced by \p this as \p newName. The
520 /// file referenced by \p this must exist. The file referenced by
521 /// \p newName does not need to exist.
523 /// @throws std::string if there is an file system error.
524 /// @brief Rename one file as another.
525 bool renamePathOnDisk(const Path& newName);
527 /// This method attempts to destroy the file or directory named by the
528 /// last component of the Path. If the Path refers to a directory and the
529 /// \p destroy_contents is false, an attempt will be made to remove just
530 /// the directory (the final Path component). If \p destroy_contents is
531 /// true, an attempt will be made to remove the entire contents of the
532 /// directory, recursively. If the Path refers to a file, the
533 /// \p destroy_contents parameter is ignored.
534 /// @param destroy_contents Indicates whether the contents of a destroyed
535 /// directory should also be destroyed (recursively).
536 /// @returns true if the file/directory was destroyed, false if the path
537 /// refers to something that is neither a file nor a directory.
538 /// @throws std::string if there is an error.
539 /// @brief Removes the file or directory from the filesystem.
540 bool eraseFromDisk( bool destroy_contents = false ) const;
546 mutable std::string path; ///< Storage for the path name.
551 /// This enumeration delineates the kinds of files that LLVM knows about.
553 UnknownFileType = 0, ///< Unrecognized file
554 BytecodeFileType = 1, ///< Uncompressed bytecode file
555 CompressedBytecodeFileType = 2, ///< Compressed bytecode file
556 ArchiveFileType = 3 ///< ar style archive file
559 /// This utility function allows any memory block to be examined in order
560 /// to determine its file type.
561 LLVMFileType IdentifyFileType(const char*magic, unsigned length);
563 /// This function can be used to copy the file specified by Src to the
564 /// file specified by Dest. If an error occurs, Dest is removed.
565 /// @throws std::string if an error opening or writing the files occurs.
566 /// @brief Copy one file to another.
567 void CopyFile(const Path& Dest, const Path& Src);
570 inline std::ostream& operator<<(std::ostream& strm, const sys::Path& aPath) {
571 strm << aPath.toString();