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
23 /// This class provides an abstraction for the path to a file or directory
24 /// in the operating system's filesystem and provides various basic operations
25 /// on it. Note that this class only represents the name of a path to a file
26 /// or directory which may or may not be valid for a given machine's file
27 /// system. A Path ensures that the name it encapsulates is syntactical valid
28 /// for the operating system it is running on but does not ensure correctness
29 /// for any particular file system. A Path either references a file or a
30 /// directory and the distinction is consistently maintained. Most operations
31 /// on the class have invariants that require the Path object to be either a
32 /// file path or a directory path, but not both. Those operations will also
33 /// leave the object as either a file path or object path. There is exactly
34 /// one invalid Path which is the empty path. The class should never allow any
35 /// other syntactically invalid non-empty path name to be assigned. Empty
36 /// paths are required in order to indicate an error result. If the path is
37 /// empty, the isValid operation will return false. All operations will fail
38 /// if isValid is false. Operations that change the path will either return
39 /// false if it would cause a syntactically invalid path name (in which case
40 /// the Path object is left unchanged) or throw an std::string exception
41 /// indicating the error.
43 /// @brief An abstraction for operating system paths.
45 /// @name Constructors
48 /// Construct a path to the root directory of the file system. The root
49 /// directory is a top level directory above which there are no more
50 /// directories. For example, on UNIX, the root directory is /. On Windows
51 /// it is C:\. Other operating systems may have different notions of
52 /// what the root directory is.
54 static Path GetRootDirectory();
56 /// Construct a path to a unique temporary directory that is created in
57 /// a "standard" place for the operating system. The directory is
58 /// guaranteed to be created on exit from this function. If the directory
59 /// cannot be created, the function will throw an exception.
60 /// @throws std::string indicating why the directory could not be created.
61 /// @brief Constrct a path to an new, unique, existing temporary
63 static Path GetTemporaryDirectory();
65 /// Determine the platform-specific location of a library by first
66 /// searching a list of library paths, then searching a list of "well
67 /// known" paths for the platform. T
68 /// @returns a valid Path object if the library was found, an invalid
71 /// @brief Locate a library in a platform specific manner.
72 static Path GetLibraryPath(const std::string& basename,
73 const std::vector<std::string>& LibPaths);
75 /// Construct a path to the first system library directory. The
76 /// implementation of Path on a given platform must ensure that this
77 /// directory both exists and also contains standard system libraries
78 /// suitable for linking into programs.
80 /// @brief Construct a path to the first system library directory
81 static Path GetSystemLibraryPath1();
83 /// Construct a path to the second system library directory. The
84 /// implementation of Path on a given platform must ensure that this
85 /// directory both exists and also contains standard system libraries
86 /// suitable for linking into programs. Note that the "second" system
87 /// library directory may or may not be different from the first.
89 /// @brief Construct a path to the second system library directory
90 static Path GetSystemLibraryPath2();
92 /// Construct a path to the default LLVM configuration directory. The
93 /// implementation must ensure that this is a well-known (same on many
94 /// systems) directory in which llvm configuration files exist. For
95 /// example, on Unix, the /etc/llvm directory has been selected.
97 /// @brief Construct a path to the default LLVM configuration directory
98 static Path GetLLVMDefaultConfigDir();
100 /// Construct a path to the LLVM installed configuration directory. The
101 /// implementation must ensure that this refers to the "etc" directory of
102 /// the LLVM installation. This is the location where configuration files
103 /// will be located for a particular installation of LLVM on a machine.
105 /// @brief Construct a path to the LLVM installed configuration directory
106 static Path GetLLVMConfigDir();
108 /// Construct a path to the current user's home directory. The
109 /// implementation must use an operating system specific mechanism for
110 /// determining the user's home directory. For example, the environment
111 /// variable "HOME" could be used on Unix. If a given operating system
112 /// does not have the concept of a user's home directory, this static
113 /// constructor must provide the same result as GetRootDirectory.
115 /// @brief Construct a path to the current user's "home" directory
116 static Path GetUserHomeDirectory();
118 /// Return the suffix commonly used on file names that contain a shared
119 /// object, shared archive, or dynamic link library. Such files are
120 /// linked at runtime into a process and their code images are shared
121 /// between processes.
122 /// @returns The dynamic link library suffix for the current platform.
123 /// @brief Return the dynamic link library suffix.
124 static std::string GetDLLSuffix();
126 /// This is one of the very few ways in which a path can be constructed
127 /// with a syntactically invalid name. The only *legal* invalid name is an
128 /// empty one. Other invalid names are not permitted. Empty paths are
129 /// provided so that they can be used to indicate null or error results in
130 /// other lib/System functionality.
132 /// @brief Construct an empty (and invalid) path.
135 /// This constructor will accept a std::string as a path but if verifies
136 /// that the path string has a legal syntax for the operating system on
137 /// which it is running. This allows a path to be taken in from outside
138 /// the program. However, if the path is not valid, the Path object will
139 /// be set to an empty string and an exception will be thrown.
140 /// @throws std::string if the path string is not legal.
141 /// @param unverified_path The path to verify and assign.
142 /// @brief Construct a Path from a string.
143 explicit Path(std::string unverified_path);
149 /// Makes a copy of \p that to \p this.
152 /// @brief Assignment Operator
153 Path & operator = ( const Path & that ) {
158 /// Compares \p this Path with \p that Path for equality.
159 /// @returns true if \p this and \p that refer to the same thing.
161 /// @brief Equality Operator
162 bool operator == (const Path& that) const {
163 return 0 == path.compare(that.path) ;
166 /// Compares \p this Path with \p that Path for inequality.
167 /// @returns true if \p this and \p that refer to different things.
169 /// @brief Inequality Operator
170 bool operator !=( const Path & that ) const {
171 return 0 != path.compare( that.path );
174 /// Determines if \p this Path is less than \p that Path. This is required
175 /// so that Path objects can be placed into ordered collections (e.g.
176 /// std::map). The comparison is done lexicographically as defined by
177 /// the std::string::compare method.
178 /// @returns true if \p this path is lexicographically less than \p that.
180 /// @brief Less Than Operator
181 bool operator< (const Path& that) const {
182 return 0 > path.compare( that.path );
189 /// This function will use an operating system specific algorithm to
190 /// determine if the current value of \p this is a syntactically valid
191 /// path name for the operating system. The path name does not need to
192 /// exist, validity is simply syntactical. Empty paths are always invalid.
193 /// @returns true iff the path name is syntactically legal for the
194 /// host operating system.
195 /// @brief Determine if a path is syntactically valid or not.
196 bool isValid() const;
198 /// This function determines if the contents of the path name are
199 /// empty. That is, the path has a zero length.
200 /// @returns true iff the path is empty.
201 /// @brief Determines if the path name is empty (invalid).
202 bool isEmpty() const { return path.empty(); }
204 /// This function determines if the path name in this object is intended
205 /// to reference a legal file name (as opposed to a directory name). This
206 /// function does not verify anything with the file system, it merely
207 /// determines if the syntax of the path represents a file name or not.
208 /// @returns true if this path name references a file.
209 /// @brief Determines if the path name references a file.
212 /// This function determines if the path name in this object is intended
213 /// to reference a legal directory name (as opposed to a file name). This
214 /// function does not verify anything with the file system, it merely
215 /// determines if the syntax of the path represents a directory name or
217 /// @returns true if the path name references a directory
218 /// @brief Determines if the path name references a directory.
219 bool isDirectory() const;
221 /// This function determines if the path name in this object references
222 /// the root (top level directory) of the file system. The details of what
223 /// is considered the "root" may vary from system to system so this method
224 /// will do the necessary checking.
225 /// @returns true iff the path name references the root directory.
226 /// @brief Determines if the path references the root directory.
227 bool isRootDirectory() const;
229 /// This function opens the file associated with the path name provided by
230 /// the Path object and reads its magic number. If the magic number at the
231 /// start of the file matches \p magic, true is returned. In all other
232 /// cases (file not found, file not accessible, etc.) it returns false.
233 /// @returns true if the magic number of the file matches \p magic.
234 /// @brief Determine if file has a specific magic number
235 bool hasMagicNumber(const std::string& magic) const;
237 /// This function determines if the path name in the object references an
238 /// archive file by looking at its magic number.
239 /// @returns true if the file starts with the magic number for an archive
241 /// @brief Determine if the path references an archive file.
242 bool isArchive() const;
244 /// This function determines if the path name in the object references an
245 /// LLVM Bytecode file by looking at its magic number.
246 /// @returns true if the file starts with the magic number for LLVM
248 /// @brief Determine if the path references a bytecode file.
249 bool isBytecodeFile() const;
251 /// This function determines if the path name references an existing file
252 /// or directory in the file system. Unlike isFile and isDirectory, this
253 /// function actually checks for the existence of the file or directory.
254 /// @returns true if the pathname references an existing file.
255 /// @brief Determines if the path is a file or directory in
259 /// This function determines if the path name references a readable file
260 /// or directory in the file system. Unlike isFile and isDirectory, this
261 /// function actually checks for the existence and readability (by the
262 /// current program) of the file or directory.
263 /// @returns true if the pathname references a readable file.
264 /// @brief Determines if the path is a readable file or directory
265 /// in the file system.
266 bool readable() const;
268 /// This function determines if the path name references a writable file
269 /// or directory in the file system. Unlike isFile and isDirectory, this
270 /// function actually checks for the existence and writability (by the
271 /// current program) of the file or directory.
272 /// @returns true if the pathname references a writable file.
273 /// @brief Determines if the path is a writable file or directory
274 /// in the file system.
275 bool writable() const;
277 /// This function determines if the path name references an executable
278 /// file in the file system. Unlike isFile and isDirectory, this
279 /// function actually checks for the existence and executability (by
280 /// the current program) of the file.
281 /// @returns true if the pathname references an executable file.
282 /// @brief Determines if the path is an executable file in the file
284 bool executable() const;
286 /// This function returns the current contents of the path as a
287 /// std::string. This allows the underlying path string to be manipulated
288 /// by other software.
289 /// @returns std::string containing the path name.
290 /// @brief Returns the path as a std::string.
291 std::string get() const { return path; }
293 /// This function returns the last component of the path name. If the
294 /// isDirectory() function would return true then this returns the name
295 /// of the last directory in the path. If the isFile() function would
296 /// return true then this function returns the name of the file without
297 /// any of the preceding directories.
298 /// @returns std::string containing the last component of the path name.
299 /// @brief Returns the last component of the path name.
300 std::string getLast() const;
302 /// This function strips off the path and suffix of the file name and
303 /// returns just the basename.
304 /// @returns std::string containing the basename of the path
306 /// @brief Get the base name of the path
307 std::string getBasename() const;
309 /// @returns a c string containing the path name.
310 /// @brief Returns the path as a C string.
311 const char* const c_str() const { return path.c_str(); }
317 /// The path name is cleared and becomes empty. This is an invalid
318 /// path name but is the *only* invalid path name. This is provided
319 /// so that path objects can be used to indicate the lack of a
320 /// valid path being found.
321 void clear() { path.clear(); }
323 /// This method attempts to set the Path object to \p unverified_path
324 /// and interpret the name as a directory name. The \p unverified_path
325 /// is verified. If verification succeeds then \p unverified_path
326 /// is accepted as a directory and true is returned. Otherwise,
327 /// the Path object remains unchanged and false is returned.
328 /// @returns true if the path was set, false otherwise.
329 /// @param unverified_path The path to be set in Path object.
331 /// @brief Set a full path from a std::string
332 bool setDirectory(const std::string& unverified_path);
334 /// This method attempts to set the Path object to \p unverified_path
335 /// and interpret the name as a file name. The \p unverified_path
336 /// is verified. If verification succeeds then \p unverified_path
337 /// is accepted as a file name and true is returned. Otherwise,
338 /// the Path object remains unchanged and false is returned.
339 /// @returns true if the path was set, false otherwise.
340 /// @param unverified_path The path to be set in Path object.
342 /// @brief Set a full path from a std::string
343 bool setFile(const std::string& unverified_path);
345 /// The \p dirname is added to the end of the Path if it is a legal
346 /// directory name for the operating system. The precondition for this
347 /// function is that the Path must reference a directory name (i.e.
348 /// isDirectory() returns true).
349 /// @param dirname A string providing the directory name to
350 /// be added to the end of the path.
351 /// @returns false if the directory name could not be added
353 /// @brief Adds the name of a directory to a Path.
354 bool appendDirectory( const std::string& dirname );
356 /// One directory component is removed from the Path name. The Path must
357 /// refer to a non-root directory name (i.e. isDirectory() returns true
358 /// but isRootDirectory() returns false). Upon exit, the Path will
359 /// refer to the directory above it.
361 /// @returns false if the directory name could not be removed.
362 /// @brief Removes the last directory component of the Path.
363 bool elideDirectory();
365 /// The \p filename is added to the end of the Path if it is a legal
366 /// directory name for the operating system. The precondition for this
367 /// function is that the Path reference a directory name (i.e.
368 /// isDirectory() returns true).
370 /// @returns false if the file name could not be added.
371 /// @brief Appends the name of a file.
372 bool appendFile( const std::string& filename );
374 /// One file component is removed from the Path name. The Path must
375 /// refer to a file (i.e. isFile() returns true). Upon exit,
376 /// the Path will refer to the directory above it.
378 /// @returns false if the file name could not be removed
379 /// @brief Removes the last file component of the path.
382 /// A period and the \p suffix are appended to the end of the pathname.
383 /// The precondition for this function is that the Path reference a file
384 /// name (i.e. isFile() returns true). If the Path is not a file, no
385 /// action is taken and the function returns false. If the path would
386 /// become invalid for the host operating system, false is returned.
387 /// @returns false if the suffix could not be added, true if it was.
389 /// @brief Adds a period and the \p suffix to the end of the pathname.
390 bool appendSuffix(const std::string& suffix);
392 /// The suffix of the filename is removed. The suffix begins with and
393 /// includes the last . character in the filename after the last directory
394 /// separator and extends until the end of the name. If no . character is
395 /// after the last directory separator, then the file name is left
396 /// unchanged (i.e. it was already without a suffix) but the function return
398 /// @returns false if there was no suffix to remove, true otherwise.
400 /// @brief Remove the suffix from a path name.
403 /// This method attempts to create a directory in the file system with the
404 /// same name as the Path object. The \p create_parents parameter controls
405 /// whether intermediate directories are created or not. if \p
406 /// create_parents is true, then an attempt will be made to create all
407 /// intermediate directories. If \p create_parents is false, then only the
408 /// final directory component of the Path name will be created. The
409 /// created directory will have no entries.
410 /// @returns false if the Path does not reference a directory, true
412 /// @param create_parents Determines whether non-existent directory
413 /// components other than the last one (the "parents") are created or not.
414 /// @throws std::string if an error occurs.
415 /// @brief Create the directory this Path refers to.
416 bool createDirectory( bool create_parents = false );
418 /// This method attempts to create a file in the file system with the same
419 /// name as the Path object. The intermediate directories must all exist
420 /// at the time this method is called. Use createDirectories to
421 /// accomplish that. The created file will be empty upon return from this
423 /// @returns false if the Path does not reference a file, true otherwise.
424 /// @throws std::string if an error occurs.
425 /// @brief Create the file this Path refers to.
428 /// This method attempts to destroy the directory named by the last in
429 /// the Path name. If \p remove_contents is false, an attempt will be
430 /// made to remove just the directory that this Path object refers to
431 /// (the final Path component). If \p remove_contents is true, an attempt
432 /// will be made to remove the entire contents of the directory,
434 /// @param destroy_contents Indicates whether the contents of a destroyed
435 /// directory should also be destroyed (recursively).
436 /// @returns false if the Path does not refer to a directory, true
438 /// @throws std::string if there is an error.
439 /// @brief Removes the file or directory from the filesystem.
440 bool destroyDirectory( bool destroy_contents = false );
442 /// This method attempts to destroy the file named by the last item in the
444 /// @returns false if the Path does not refer to a file, true otherwise.
445 /// @throws std::string if there is an error.
446 /// @brief Destroy the file this Path refers to.
453 std::string path; ///< Platform agnostic storage for the path name.