[llvm-commits] CVS: llvm/include/llvm/System/Path.h
Reid Spencer
reid at x10sys.com
Sat Aug 28 22:24:12 PDT 2004
Changes in directory llvm/include/llvm/System:
Path.h updated: 1.3 -> 1.4
---
Log message:
Revise the design of the Path concept per peer review. Too many changes to
note individually but these essence of it is to not derive from
std::string, clarify the interface, and provide better documentation.
There is now also (untested) implementations for AIX, Darwin, and SunOS.
---
Diffs of the changes: (+376 -122)
Index: llvm/include/llvm/System/Path.h
diff -u llvm/include/llvm/System/Path.h:1.3 llvm/include/llvm/System/Path.h:1.4
--- llvm/include/llvm/System/Path.h:1.3 Wed Aug 25 01:20:07 2004
+++ llvm/include/llvm/System/Path.h Sun Aug 29 00:24:00 2004
@@ -19,138 +19,392 @@
namespace llvm {
namespace sys {
- /// This class provides an abstraction for the name of a path
- /// to a file or directory in the filesystem and various basic operations
- /// on it.
+ /// This class provides an abstraction for the path to a file or directory
+ /// in the operating system's filesystem and provides various basic operations
+ /// on it. Note that this class only represents the name of a path to a file
+ /// or directory which may or may not be valid for a given machine's file
+ /// system. A Path ensures that the name it encapsulates is syntactical valid
+ /// for the operating system it is running on but does not ensure correctness
+ /// for any particular file system. A Path either references a file or a
+ /// directory and the distinction is consistently maintained. Most operations
+ /// on the class have invariants that require the Path object to be either a
+ /// file path or a directory path, but not both. Those operations will also
+ /// leave the object as either a file path or object path. There is exactly
+ /// one invalid Path which is the empty path. The class should never allow any
+ /// other syntactically invalid non-empty path name to be assigned. Empty
+ /// paths are required in order to indicate an error result. If the path is
+ /// empty, the is_valid operation will return false. All operations will fail
+ /// if is_valid is false. Operations that change the path will either return
+ /// false if it would cause a syntactically invalid path name (in which case
+ /// the Path object is left unchanged) or throw an std::string exception
+ /// indicating the error.
/// @since 1.4
/// @brief An abstraction for operating system paths.
- class Path : public std::string {
- /// @name Constructors
- /// @{
- public:
- /// Creates a null (empty) path
- /// @brief Default Constructor
- Path () : std::string() {}
-
- /// Creates a path from char*
- /// @brief char* converter
- Path ( const char * name ) : std::string(name) {
- assert(is_valid());
- }
-
- /// @brief std::string converter
- Path ( const std::string& name ) : std::string(name){
- assert(is_valid());
- };
-
- /// Copies the path with copy-on-write semantics. The \p this Path
- /// will reference \p the that Path until one of them is modified
- /// at which point a full copy is taken before the write.
- /// @brief Copy Constructor
- Path ( const Path & that ) : std::string(that) {}
-
- /// Releases storage associated with the Path object
- /// @brief Destructor
- ~Path ( void ) {};
-
- /// @}
- /// @name Operators
- /// @{
- public:
- /// Makes a copy of \p that to \p this with copy-on-write semantics.
- /// @returns \p this
- /// @brief Assignment Operator
- Path & operator = ( const Path & that ) {
- this->assign (that);
- return *this;
- }
-
- /// Comparies \p this Path with \p that Path for equality.
- /// @returns true if \p this and \p that refer to the same item.
- /// @brief Equality Operator
- bool operator ==( const Path & that ) const {
- return 0 == this->compare( that ) ;
- }
-
- /// Comparies \p this Path with \p that Path for inequality.
- /// @returns true if \p this and \p that refer to different items.
- /// @brief Inequality Operator
- bool operator !=( const Path & that ) const {
- return 0 != this->compare( that );
- }
-
- /// @}
- /// @name Accessors
- /// @{
- public:
- /// @returns true if the path is valid
- /// @brief Determines if the path is valid (properly formed) or not.
- bool is_valid() const;
-
- /// @returns true if the path could reference a file
- /// @brief Determines if the path is valid for a file reference.
- bool is_file() const;
-
- /// @returns true if the path could reference a directory
- /// @brief Determines if the path is valid for a directory reference.
- bool is_directory() const;
-
- /// @brief Fills and zero terminates a buffer with the path
- void fill( char* buffer, unsigned len ) const;
-
- /// @}
- /// @name Mutators
- /// @{
- public:
- /// This ensures that the pathname is terminated with a /
- /// @brief Make the path reference a directory.
- void make_directory();
-
- /// This ensures that the pathname is not terminated with a /
- /// @brief Makes the path reference a file.
- void make_file();
+ class Path {
+ /// @name Constructors
+ /// @{
+ public:
+ /// Construct a path to the root directory of the file system. The root
+ /// directory is a top level directory above which there are no more
+ /// directories. For example, on UNIX, the root directory is /. On Windows
+ /// it is C:\. Other operating systems may have different notions of
+ /// what the root directory is.
+ /// @throws nothing
+ static Path GetRootDirectory();
+
+ /// Construct a path to a unique temporary directory that is created in
+ /// a "standard" place for the operating system. The directory is
+ /// guaranteed to be created on exit from this function. If the directory
+ /// cannot be created, the function will throw an exception.
+ /// @throws std::string indicating why the directory could not be created.
+ /// @brief Constrct a path to an new, unique, existing temporary
+ /// directory.
+ static Path GetTemporaryDirectory();
+
+ /// Construct a path to the first system library directory. The
+ /// implementation of Path on a given platform must ensure that this
+ /// directory both exists and also contains standard system libraries
+ /// suitable for linking into programs.
+ /// @throws nothing
+ /// @brief Construct a path to the first system library directory
+ static Path GetSystemLibraryPath1();
+
+ /// Construct a path to the second system library directory. The
+ /// implementation of Path on a given platform must ensure that this
+ /// directory both exists and also contains standard system libraries
+ /// suitable for linking into programs. Note that the "second" system
+ /// library directory may or may not be different from the first.
+ /// @throws nothing
+ /// @brief Construct a path to the second system library directory
+ static Path GetSystemLibraryPath2();
+
+ /// Construct a path to the default LLVM configuration directory. The
+ /// implementation must ensure that this is a well-known (same on many
+ /// systems) directory in which llvm configuration files exist. For
+ /// example, on Unix, the /etc/llvm directory has been selected.
+ /// @throws nothing
+ /// @brief Construct a path to the default LLVM configuration directory
+ static Path GetLLVMDefaultConfigDir();
+
+ /// Construct a path to the LLVM installed configuration directory. The
+ /// implementation must ensure that this refers to the "etc" directory of
+ /// the LLVM installation. This is the location where configuration files
+ /// will be located for a particular installation of LLVM on a machine.
+ /// @throws nothing
+ /// @brief Construct a path to the LLVM installed configuration directory
+ static Path GetLLVMConfigDir();
+
+ /// Construct a path to the current user's home directory. The
+ /// implementation must use an operating system specific mechanism for
+ /// determining the user's home directory. For example, the environment
+ /// variable "HOME" could be used on Unix. If a given operating system
+ /// does not have the concept of a user's home directory, this static
+ /// constructor must provide the same result as GetRootDirectory.
+ /// @throws nothing
+ /// @brief Construct a path to the current user's "home" directory
+ static Path GetUserHomeDirectory();
+
+ /// This is one of the very few ways in which a path can be constructed
+ /// with a syntactically invalid name. The only *legal* invalid name is an
+ /// empty one. Other invalid names are not permitted. Empty paths are
+ /// provided so that they can be used to indicate null or error results in
+ /// other lib/System functionality.
+ /// @throws nothing
+ /// @brief Construct an empty (and invalid) path.
+ Path() : path() {}
+
+ /// This constructor will accept a std::string as a path but if verifies
+ /// that the path string has a legal syntax for the operating system on
+ /// which it is running. This allows a path to be taken in from outside
+ /// the program. However, if the path is not valid, the Path object will
+ /// be set to an empty string and an exception will be thrown.
+ /// @throws std::string if the path string is not legal.
+ /// @param unvalidated_path The path to verify and assign.
+ /// @brief Construct a Path from a string.
+ explicit Path(std::string unverified_path);
+
+ /// @}
+ /// @name Operators
+ /// @{
+ public:
+ /// Makes a copy of \p that to \p this.
+ /// @returns \p this
+ /// @throws nothing
+ /// @brief Assignment Operator
+ Path & operator = ( const Path & that ) {
+ path = that.path;
+ return *this;
+ }
- /// the file system.
+ /// Compares \p this Path with \p that Path for equality.
+ /// @returns true if \p this and \p that refer to the same thing.
+ /// @throws nothing
+ /// @brief Equality Operator
+ bool operator == (const Path& that) const {
+ return 0 == path.compare(that.path) ;
+ }
+
+ /// Compares \p this Path with \p that Path for inequality.
+ /// @returns true if \p this and \p that refer to different things.
+ /// @throws nothing
+ /// @brief Inequality Operator
+ bool operator !=( const Path & that ) const {
+ return 0 != path.compare( that.path );
+ }
+
+ /// Determines if \p this Path is less than \p that Path. This is required
+ /// so that Path objects can be placed into ordered collections (e.g.
+ /// std::map). The comparison is done lexicographically as defined by
+ /// the std::string::compare method.
+ /// @returns true if \p this path is lexicographically less than \p that.
+ /// @throws nothing
+ /// @brief Less Than Operator
+ bool operator< (const Path& that) const {
+ return 0 > path.compare( that.path );
+ }
+
+ /// @}
+ /// @name Accessors
+ /// @{
+ public:
+ /// This function will use an operating system specific algorithm to
+ /// determine if the current value of \p this is a syntactically valid
+ /// path name for the operating system. The path name does not need to
+ /// exist, validity is simply syntactical. Empty paths are always invalid.
+ /// @returns true iff the path name is syntactically legal for the
+ /// host operating system.
+ /// @brief Determine if a path is syntactically valid or not.
+ bool is_valid() const;
+
+ /// This function determines if the contents of the path name are
+ /// empty. That is, the path has a zero length.
+ /// @returns true iff the path is empty.
+ /// @brief Determines if the path name is empty (invalid).
+ bool is_empty() const { return path.empty(); }
+
+ /// This function determines if the path name in this object is intended
+ /// to reference a legal file name (as opposed to a directory name). This
+ /// function does not verify anything with the file system, it merely
+ /// determines if the syntax of the path represents a file name or not.
+ /// @returns true if this path name references a file.
+ /// @brief Determines if the path name references a file.
+ bool is_file() const;
+
+ /// This function determines if the path name in this object is intended
+ /// to reference a legal directory name (as opposed to a file name). This
+ /// function does not verify anything with the file system, it merely
+ /// determines if the syntax of the path represents a directory name or
+ /// not.
+ /// @returns true if the path name references a directory
+ /// @brief Determines if the path name references a directory.
+ bool is_directory() const;
+
+ /// This function determines if the path name in this object references
+ /// the root (top level directory) of the file system. The details of what
+ /// is considered the "root" may vary from system to system so this method
+ /// will do the necessary checking.
+ /// @returns true iff the path name references the root directory.
+ /// @brief Determines if the path references the root directory.
+ bool is_root_directory() const;
+
+ /// This function determines if the path name references an existing file
+ /// or directory in the file system. Unlike is_file and is_directory, this
+ /// function actually checks for the existence of the file or directory.
/// @returns true if the pathname references an existing file.
/// @brief Determines if the path is a file or directory in
- bool exists();
+ /// the file system.
+ bool exists() const;
- /// The \p dirname is added to the end of the Path.
+ /// This function determines if the path name references a readable file
+ /// or directory in the file system. Unlike is_file and is_directory, this
+ /// function actually checks for the existence and readability (by the
+ /// current program) of the file or directory.
+ /// @returns true if the pathname references a readable file.
+ /// @brief Determines if the path is a readable file or directory
+ /// in the file system.
+ bool readable() const;
+
+ /// This function determines if the path name references a writable file
+ /// or directory in the file system. Unlike is_file and is_directory, this
+ /// function actually checks for the existence and writability (by the
+ /// current program) of the file or directory.
+ /// @returns true if the pathname references a writable file.
+ /// @brief Determines if the path is a writable file or directory
+ /// in the file system.
+ bool writable() const;
+
+ /// This function determines if the path name references an executable
+ /// file in the file system. Unlike is_file and is_directory, this
+ /// function actually checks for the existence and executability (by
+ /// the current program) of the file.
+ /// @returns true if the pathname references an executable file.
+ /// @brief Determines if the path is an executable file in the file
+ /// system.
+ bool executable() const;
+
+ /// This function returns the current contents of the path as a
+ /// std::string. This allows the underlying path string to be manipulated
+ /// by other software.
+ /// @returns std::string containing the path name.
+ /// @brief Returns the path as a std::string.
+ std::string get() const { return path; }
+
+ /// This function returns the last component of the path name. If the
+ /// is_directory() function would return true then this returns the name
+ /// of the last directory in the path. If the is_file() function would
+ /// return true then this function returns the name of the file without
+ /// any of the preceding directories.
+ /// @returns std::string containing the last component of the path name.
+ /// @brief Returns the last component of the path name.
+ std::string getLast() const;
+
+ /// @returns a c string containing the path name.
+ /// @brief Returns the path as a C string.
+ const char* const c_str() const { return path.c_str(); }
+
+ /// @}
+ /// @name Mutators
+ /// @{
+ public:
+ /// The path name is cleared and becomes empty. This is an invalid
+ /// path name but is the *only* invalid path name. This is provided
+ /// so that path objects can be used to indicate the lack of a
+ /// valid path being found.
+ void clear() { path.clear(); }
+
+ /// This method attempts to set the Path object to \p unverified_path
+ /// and interpret the name as a directory name. The \p unverified_path
+ /// is verified. If verification succeeds then \p unverified_path
+ /// is accepted as a directory and true is returned. Otherwise,
+ /// the Path object remains unchanged and false is returned.
+ /// @returns true if the path was set, false otherwise.
+ /// @param unverified_path The path to be set in Path object.
+ /// @throws nothing
+ /// @brief Set a full path from a std::string
+ bool set_directory(const std::string& unverified_path);
+
+ /// This method attempts to set the Path object to \p unverified_path
+ /// and interpret the name as a file name. The \p unverified_path
+ /// is verified. If verification succeeds then \p unverified_path
+ /// is accepted as a file name and true is returned. Otherwise,
+ /// the Path object remains unchanged and false is returned.
+ /// @returns true if the path was set, false otherwise.
+ /// @param unverified_path The path to be set in Path object.
+ /// @throws nothing
+ /// @brief Set a full path from a std::string
+ bool set_file(const std::string& unverified_path);
+
+ /// The \p dirname is added to the end of the Path if it is a legal
+ /// directory name for the operating system. The precondition for this
+ /// function is that the Path must reference a directory name (i.e.
+ /// is_directory() returns true).
/// @param dirname A string providing the directory name to
- /// be appended to the path.
- /// @brief Appends the name of a directory.
- void append_directory( const std::string& dirname ) {
- this->append( dirname );
- make_directory();
- }
-
- /// The \p filename is added to the end of the Path.
+ /// be added to the end of the path.
+ /// @returns false if the directory name could not be added
+ /// @throws nothing
+ /// @brief Adds the name of a directory to a Path.
+ bool append_directory( const std::string& dirname );
+
+ /// One directory component is removed from the Path name. The Path must
+ /// refer to a non-root directory name (i.e. is_directory() returns true
+ /// but is_root_directory() returns false). Upon exit, the Path will
+ /// refer to the directory above it.
+ /// @throws nothing
+ /// @returns false if the directory name could not be removed.
+ /// @brief Removes the last directory component of the Path.
+ bool elide_directory();
+
+ /// The \p filename is added to the end of the Path if it is a legal
+ /// directory name for the operating system. The precondition for this
+ /// function is that the Path reference a directory name (i.e.
+ /// is_directory() returns true).
+ /// @throws nothing
+ /// @returns false if the file name could not be added.
/// @brief Appends the name of a file.
- void append_file( const std::string& filename ) {
- this->append( filename );
- }
+ bool append_file( const std::string& filename );
- /// Directories will have no entries. Files will be zero length. If
- /// the file or directory already exists, no error results.
- /// @throws SystemException if any error occurs.
- /// @brief Causes the file or directory to exist in the filesystem.
- void create( bool create_parents = false );
-
- void create_directory( void );
- void create_directories( void );
- void create_file( void );
-
- /// Directories must be empty before they can be removed. If not,
- /// an error will result. Files will be unlinked, even if another
- /// process is using them.
+ /// One file component is removed from the Path name. The Path must
+ /// refer to a file (i.e. is_file() returns true). Upon exit,
+ /// the Path will refer to the directory above it.
+ /// @throws nothing
+ /// @returns false if the file name could not be removed
+ /// @brief Removes the last file component of the path.
+ bool elide_file();
+
+ /// A period and the \p suffix are appended to the end of the pathname.
+ /// The precondition for this function is that the Path reference a file
+ /// name (i.e. is_file() returns true). If the Path is not a file, no
+ /// action is taken and the function returns false. If the path would
+ /// become invalid for the host operating system, false is returned.
+ /// @returns false if the suffix could not be added, true if it was.
+ /// @throws nothing
+ /// @brief Adds a period and the \p suffix to the end of the pathname.
+ bool append_suffix(const std::string& suffix);
+
+ /// The suffix of the filename is removed. The suffix begins with and
+ /// includes the last . character in the filename after the last directory
+ /// separator and extends until the end of the name. If no . character is
+ /// after the last directory separator, then the file name is left
+ /// unchanged (i.e. it was already without a suffix) but the function return
+ /// false.
+ /// @returns false if there was no suffix to remove, true otherwise.
+ /// @throws nothing
+ /// @brief Remove the suffix from a path name.
+ bool elide_suffix();
+
+ /// This method attempts to create a directory in the file system with the
+ /// same name as the Path object. The \p create_parents parameter controls
+ /// whether intermediate directories are created or not. if \p
+ /// create_parents is true, then an attempt will be made to create all
+ /// intermediate directories. If \p create_parents is false, then only the
+ /// final directory component of the Path name will be created. The
+ /// created directory will have no entries.
+ /// @returns false if the Path does not reference a directory, true
+ /// otherwise.
+ /// @param create_parents Determines whether non-existent directory
+ /// components other than the last one (the "parents") are created or not.
+ /// @throws std::string if an error occurs.
+ /// @brief Create the directory this Path refers to.
+ bool create_directory( bool create_parents = false );
+
+ /// This method attempts to create a file in the file system with the same
+ /// name as the Path object. The intermediate directories must all exist
+ /// at the time this method is called. Use create_directories to
+ /// accomplish that. The created file will be empty upon return from this
+ /// function.
+ /// @returns false if the Path does not reference a file, true otherwise.
+ /// @throws std::string if an error occurs.
+ /// @brief Create the file this Path refers to.
+ bool create_file();
+
+ /// This method attempts to destroy the directory named by the last in
+ /// the Path name. If \p remove_contents is false, an attempt will be
+ /// made to remove just the directory that this Path object refers to
+ /// (the final Path component). If \p remove_contents is true, an attempt
+ /// will be made to remove the entire contents of the directory,
+ /// recursively.
+ /// @param destroy_contents Indicates whether the contents of a destroyed
+ /// directory should also be destroyed (recursively).
+ /// @returns false if the Path does not refer to a directory, true
+ /// otherwise.
+ /// @throws std::string if there is an error.
/// @brief Removes the file or directory from the filesystem.
- void remove( void );
- void remove_directory( void );
- void remove_file( void );
-
- /// Find library.
- void find_lib( const char * file );
- /// @}
+ bool destroy_directory( bool destroy_contents = false );
+
+ /// This method attempts to destroy the file named by the last item in the
+ /// Path name.
+ /// @returns false if the Path does not refer to a file, true otherwise.
+ /// @throws std::string if there is an error.
+ /// @brief Destroy the file this Path refers to.
+ bool destroy_file();
+
+ /// @}
+ /// @name Data
+ /// @{
+ private:
+ std::string path; ///< Platform agnostic storage for the path name.
+
+ /// @}
};
}
}
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