Support: Rename Path.h to PathV1.h and add a new Path.h that includes both V1 and V2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122065 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 738 insertions, 722 deletions

diff --git a/include/llvm/Support/Path.h b/include/llvm/Support/Path.h
index 879f013..196eecc 100644
--- a/include/llvm/Support/Path.h
+++ b/include/llvm/Support/Path.h
@@ -1,4 +1,4 @@
-//===- llvm/Support/Path.h - Path Operating System Concept -------*- C++ -*-===//
+//===- llvm/Support/Path.h - Path Operating System Concept ------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,727 +7,10 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file declares the llvm::sys::Path class.
+// This file currently includes both PathV1 and PathV2 to facilitate moving
+// clients over to the new interface.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_SYSTEM_PATH_H
-#define LLVM_SYSTEM_PATH_H
-
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/TimeValue.h"
-#include <set>
-#include <string>
-#include <vector>
-
-namespace llvm {
-namespace sys {
-
-  /// This structure provides basic file system information about a file. It
-  /// is patterned after the stat(2) Unix operating system call but made
-  /// platform independent and eliminates many of the unix-specific fields.
-  /// However, to support llvm-ar, the mode, user, and group fields are
-  /// retained. These pertain to unix security and may not have a meaningful
-  /// value on non-Unix platforms. However, the other fields should
-  /// always be applicable on all platforms.  The structure is filled in by
-  /// the PathWithStatus class.
-  /// @brief File status structure
-  class FileStatus {
-  public:
-    uint64_t    fileSize;   ///< Size of the file in bytes
-    TimeValue   modTime;    ///< Time of file's modification
-    uint32_t    mode;       ///< Mode of the file, if applicable
-    uint32_t    user;       ///< User ID of owner, if applicable
-    uint32_t    group;      ///< Group ID of owner, if applicable
-    uint64_t    uniqueID;   ///< A number to uniquely ID this file
-    bool        isDir  : 1; ///< True if this is a directory.
-    bool        isFile : 1; ///< True if this is a file.
-
-    FileStatus() : fileSize(0), modTime(0,0), mode(0777), user(999),
-                   group(999), uniqueID(0), isDir(false), isFile(false) { }
-
-    TimeValue getTimestamp() const { return modTime; }
-    uint64_t getSize() const { return fileSize; }
-    uint32_t getMode() const { return mode; }
-    uint32_t getUser() const { return user; }
-    uint32_t getGroup() const { return group; }
-    uint64_t getUniqueID() const { return uniqueID; }
-  };
-
-  /// 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. The class is patterned after the java.io.File class with various
-  /// extensions and several omissions (not relevant to LLVM).  A Path object
-  /// ensures that the path it encapsulates is syntactically valid for the
-  /// operating system it is running on but does not ensure correctness for
-  /// any particular file system. That is, a syntactically valid path might
-  /// specify path components that do not exist in the file system and using
-  /// such a Path to act on the file system could produce errors. There is one
-  /// invalid Path value which is permitted: the empty path.  The class should
-  /// never allow a syntactically invalid non-empty path name to be assigned.
-  /// Empty paths are required in order to indicate an error result in some
-  /// situations. If the path is empty, the isValid operation will return
-  /// false. All operations will fail if isValid 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. The methods are
-  /// grouped into four basic categories: Path Accessors (provide information
-  /// about the path without accessing disk), Disk Accessors (provide
-  /// information about the underlying file or directory), Path Mutators
-  /// (change the path information, not the disk), and Disk Mutators (change
-  /// the disk file/directory referenced by the path). The Disk Mutator methods
-  /// all have the word "disk" embedded in their method name to reinforce the
-  /// notion that the operation modifies the file system.
-  /// @since 1.4
-  /// @brief An abstraction for operating system paths.
-  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 file:///. Other operating systems may have different notions of
-      /// what the root directory is or none at all. In that case, a consistent
-      /// default root directory will be used.
-      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.
-      /// @returns an invalid path (empty) on error
-      /// @param ErrMsg Optional place for an error message if an error occurs
-      /// @brief Constrct a path to an new, unique, existing temporary
-      /// directory.
-      static Path GetTemporaryDirectory(std::string* ErrMsg = 0);
-
-      /// Construct a vector of sys::Path that contains the "standard" system
-      /// library paths suitable for linking into programs.
-      /// @brief Construct a path to the system library directory
-      static void GetSystemLibraryPaths(std::vector<sys::Path>& Paths);
-
-      /// Construct a vector of sys::Path that contains the "standard" bitcode
-      /// library paths suitable for linking into an llvm program. This function
-      /// *must* return the value of LLVM_LIB_SEARCH_PATH as well as the value
-      /// of LLVM_LIBDIR. It also must provide the System library paths as
-      /// returned by GetSystemLibraryPaths.
-      /// @see GetSystemLibraryPaths
-      /// @brief Construct a list of directories in which bitcode could be
-      /// found.
-      static void GetBitcodeLibraryPaths(std::vector<sys::Path>& Paths);
-
-      /// Find the path to a library using its short name. Use the system
-      /// dependent library paths to locate the library.
-      /// @brief Find a library.
-      static Path FindLibrary(std::string& short_name);
-
-      /// 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.
-      /// @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.
-      /// @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.
-      /// @brief Construct a path to the current user's "home" directory
-      static Path GetUserHomeDirectory();
-
-      /// Construct a path to the current directory for the current process.
-      /// @returns The current working directory.
-      /// @brief Returns the current working directory.
-      static Path GetCurrentDirectory();
-
-      /// Return the suffix commonly used on file names that contain an
-      /// executable.
-      /// @returns The executable file suffix for the current platform.
-      /// @brief Return the executable file suffix.
-      static StringRef GetEXESuffix();
-
-      /// Return the suffix commonly used on file names that contain a shared
-      /// object, shared archive, or dynamic link library. Such files are
-      /// linked at runtime into a process and their code images are shared
-      /// between processes.
-      /// @returns The dynamic link library suffix for the current platform.
-      /// @brief Return the dynamic link library suffix.
-      static StringRef GetDLLSuffix();
-
-      /// GetMainExecutable - Return the path to the main executable, given the
-      /// value of argv[0] from program startup and the address of main itself.
-      /// In extremis, this function may fail and return an empty path.
-      static Path GetMainExecutable(const char *argv0, void *MainAddr);
-
-      /// 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.
-      /// @brief Construct an empty (and invalid) path.
-      Path() : path() {}
-      Path(const Path &that) : path(that.path) {}
-
-      /// This constructor will accept a char* or std::string as a path. No
-      /// checking is done on this path to determine if it is valid. To
-      /// determine validity of the path, use the isValid method.
-      /// @param p The path to assign.
-      /// @brief Construct a Path from a string.
-      explicit Path(StringRef p);
-
-      /// This constructor will accept a character range as a path.  No checking
-      /// is done on this path to determine if it is valid.  To determine
-      /// validity of the path, use the isValid method.
-      /// @param StrStart A pointer to the first character of the path name
-      /// @param StrLen The length of the path name at StrStart
-      /// @brief Construct a Path from a string.
-      Path(const char *StrStart, unsigned StrLen);
-
-    /// @}
-    /// @name Operators
-    /// @{
-    public:
-      /// Makes a copy of \p that to \p this.
-      /// @returns \p this
-      /// @brief Assignment Operator
-      Path &operator=(const Path &that) {
-        path = that.path;
-        return *this;
-      }
-
-      /// Makes a copy of \p that to \p this.
-      /// @param that A StringRef denoting the path
-      /// @returns \p this
-      /// @brief Assignment Operator
-      Path &operator=(StringRef that);
-
-      /// Compares \p this Path with \p that Path for equality.
-      /// @returns true if \p this and \p that refer to the same thing.
-      /// @brief Equality Operator
-      bool operator==(const Path &that) const;
-
-      /// Compares \p this Path with \p that Path for inequality.
-      /// @returns true if \p this and \p that refer to different things.
-      /// @brief Inequality Operator
-      bool operator!=(const Path &that) const { return !(*this == that); }
-
-      /// 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.
-      /// @brief Less Than Operator
-      bool operator<(const Path& that) const;
-
-    /// @}
-    /// @name Path 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 isValid() const;
-
-      /// This function determines if the contents of the path name are empty.
-      /// That is, the path name has a zero length. This does NOT determine if
-      /// if the file is empty. To get the length of the file itself, Use the
-      /// PathWithStatus::getFileStatus() method and then the getSize() method
-      /// on the returned FileStatus object.
-      /// @returns true iff the path is empty.
-      /// @brief Determines if the path name is empty (invalid).
-      bool isEmpty() const { return path.empty(); }
-
-       /// This function returns the last component of the path name. The last
-      /// component is the file or directory name occuring after the last
-      /// directory separator. If no directory separator is present, the entire
-      /// path name is returned (i.e. same as toString).
-      /// @returns StringRef containing the last component of the path name.
-      /// @brief Returns the last component of the path name.
-      StringRef getLast() const;
-
-      /// This function strips off the path and suffix of the file or directory
-      /// name and returns just the basename. For example /a/foo.bar would cause
-      /// this function to return "foo".
-      /// @returns StringRef containing the basename of the path
-      /// @brief Get the base name of the path
-      StringRef getBasename() const;
-
-      /// This function strips off the suffix of the path beginning with the
-      /// path separator ('/' on Unix, '\' on Windows) and returns the result.
-      StringRef getDirname() const;
-
-      /// This function strips off the path and basename(up to and
-      /// including the last dot) of the file or directory name and
-      /// returns just the suffix. For example /a/foo.bar would cause
-      /// this function to return "bar".
-      /// @returns StringRef containing the suffix of the path
-      /// @brief Get the suffix of the path
-      StringRef getSuffix() const;
-
-      /// Obtain a 'C' string for the path name.
-      /// @returns a 'C' string containing the path name.
-      /// @brief Returns the path as a C string.
-      const char *c_str() const { return path.c_str(); }
-      const std::string &str() const { return path; }
-
-
-      /// size - Return the length in bytes of this path name.
-      size_t size() const { return path.size(); }
-
-      /// empty - Returns true if the path is empty.
-      unsigned empty() const { return path.empty(); }
-
-    /// @}
-    /// @name Disk Accessors
-    /// @{
-    public:
-      /// This function determines if the path name is absolute, as opposed to
-      /// relative.
-      /// @brief Determine if the path is absolute.
-      bool isAbsolute() const;
-
-      /// This function determines if the path name is absolute, as opposed to
-      /// relative.
-      /// @brief Determine if the path is absolute.
-      static bool isAbsolute(const char *NameStart, unsigned NameLen);
-
-      /// This function opens the file associated with the path name provided by
-      /// the Path object and reads its magic number. If the magic number at the
-      /// start of the file matches \p magic, true is returned. In all other
-      /// cases (file not found, file not accessible, etc.) it returns false.
-      /// @returns true if the magic number of the file matches \p magic.
-      /// @brief Determine if file has a specific magic number
-      bool hasMagicNumber(StringRef magic) const;
-
-      /// This function retrieves the first \p len bytes of the file associated
-      /// with \p this. These bytes are returned as the "magic number" in the
-      /// \p Magic parameter.
-      /// @returns true if the Path is a file and the magic number is retrieved,
-      /// false otherwise.
-      /// @brief Get the file's magic number.
-      bool getMagicNumber(std::string& Magic, unsigned len) const;
-
-      /// This function determines if the path name in the object references an
-      /// archive file by looking at its magic number.
-      /// @returns true if the file starts with the magic number for an archive
-      /// file.
-      /// @brief Determine if the path references an archive file.
-      bool isArchive() const;
-
-      /// This function determines if the path name in the object references an
-      /// LLVM Bitcode file by looking at its magic number.
-      /// @returns true if the file starts with the magic number for LLVM
-      /// bitcode files.
-      /// @brief Determine if the path references a bitcode file.
-      bool isBitcodeFile() const;
-
-      /// This function determines if the path name in the object references a
-      /// native Dynamic Library (shared library, shared object) by looking at
-      /// the file's magic number. The Path object must reference a file, not a
-      /// directory.
-      /// @returns true if the file starts with the magic number for a native
-      /// shared library.
-      /// @brief Determine if the path references a dynamic library.
-      bool isDynamicLibrary() const;
-
-      /// This function determines if the path name in the object references a
-      /// native object file by looking at it's magic number. The term object
-      /// file is defined as "an organized collection of separate, named
-      /// sequences of binary data." This covers the obvious file formats such
-      /// as COFF and ELF, but it also includes llvm ir bitcode, archives,
-      /// libraries, etc...
-      /// @returns true if the file starts with the magic number for an object
-      /// file.
-      /// @brief Determine if the path references an object file.
-      bool isObjectFile() const;
-
-      /// This function determines if the path name references an existing file
-      /// or directory in the file system.
-      /// @returns true if the pathname references an existing file or
-      /// directory.
-      /// @brief Determines if the path is a file or directory in
-      /// the file system.
-      bool exists() const;
-
-      /// This function determines if the path name references an
-      /// existing directory.
-      /// @returns true if the pathname references an existing directory.
-      /// @brief Determines if the path is a directory in the file system.
-      bool isDirectory() const;
-
-      /// This function determines if the path name references an
-      /// existing symbolic link.
-      /// @returns true if the pathname references an existing symlink.
-      /// @brief Determines if the path is a symlink in the file system.
-      bool isSymLink() const;
-
-      /// This function determines if the path name references a readable file
-      /// or directory in the file system. This function 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 canRead() const;
-
-      /// This function determines if the path name references a writable file
-      /// or directory in the file system. This function 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 canWrite() const;
-
-      /// This function checks that what we're trying to work only on a regular
-      /// file. Check for things like /dev/null, any block special file, or
-      /// other things that aren't "regular" regular files.
-      /// @returns true if the file is S_ISREG.
-      /// @brief Determines if the file is a regular file
-      bool isRegularFile() const;
-
-      /// This function determines if the path name references an executable
-      /// file in the file system. This function 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 canExecute() const;
-
-      /// This function builds a list of paths that are the names of the
-      /// files and directories in a directory.
-      /// @returns true if an error occurs, true otherwise
-      /// @brief Build a list of directory's contents.
-      bool getDirectoryContents(
-        std::set<Path> &paths, ///< The resulting list of file & directory names
-        std::string* ErrMsg    ///< Optional place to return an error message.
-      ) const;
-
-    /// @}
-    /// @name Path 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.
-      /// @brief Make the path empty.
-      void clear() { path.clear(); }
-
-      /// This method sets the Path object to \p unverified_path. This can fail
-      /// if the \p unverified_path does not pass the syntactic checks of the
-      /// isValid() method. If verification fails, the Path object remains
-      /// unchanged and false is returned. Otherwise true is returned and the
-      /// Path object takes on the path value of \p unverified_path
-      /// @returns true if the path was set, false otherwise.
-      /// @param unverified_path The path to be set in Path object.
-      /// @brief Set a full path from a StringRef
-      bool set(StringRef unverified_path);
-
-      /// One path component is removed from the Path. If only one component is
-      /// present in the path, the Path object becomes empty. If the Path object
-      /// is empty, no change is made.
-      /// @returns false if the path component could not be removed.
-      /// @brief Removes the last directory component of the Path.
-      bool eraseComponent();
-
-      /// The \p component is added to the end of the Path if it is a legal
-      /// name for the operating system. A directory separator will be added if
-      /// needed.
-      /// @returns false if the path component could not be added.
-      /// @brief Appends one path component to the Path.
-      bool appendComponent(StringRef component);
-
-      /// A period and the \p suffix are appended to the end of the pathname.
-      /// When the \p suffix is empty, no action is performed.
-      /// @brief Adds a period and the \p suffix to the end of the pathname.
-      void appendSuffix(StringRef suffix);
-
-      /// The suffix of the filename is erased. 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
-      /// returns false.
-      /// @returns false if there was no suffix to remove, true otherwise.
-      /// @brief Remove the suffix from a path name.
-      bool eraseSuffix();
-
-      /// The current Path name is made unique in the file system. Upon return,
-      /// the Path will have been changed to make a unique file in the file
-      /// system or it will not have been changed if the current path name is
-      /// already unique.
-      /// @throws std::string if an unrecoverable error occurs.
-      /// @brief Make the current path name unique in the file system.
-      bool makeUnique( bool reuse_current /*= true*/, std::string* ErrMsg );
-
-      /// The current Path name is made absolute by prepending the
-      /// current working directory if necessary.
-      void makeAbsolute();
-
-    /// @}
-    /// @name Disk Mutators
-    /// @{
-    public:
-      /// This method attempts to make the file referenced by the Path object
-      /// available for reading so that the canRead() method will return true.
-      /// @brief Make the file readable;
-      bool makeReadableOnDisk(std::string* ErrMsg = 0);
-
-      /// This method attempts to make the file referenced by the Path object
-      /// available for writing so that the canWrite() method will return true.
-      /// @brief Make the file writable;
-      bool makeWriteableOnDisk(std::string* ErrMsg = 0);
-
-      /// This method attempts to make the file referenced by the Path object
-      /// available for execution so that the canExecute() method will return
-      /// true.
-      /// @brief Make the file readable;
-      bool makeExecutableOnDisk(std::string* ErrMsg = 0);
-
-      /// This method allows the last modified time stamp and permission bits
-      /// to be set on the disk object referenced by the Path.
-      /// @throws std::string if an error occurs.
-      /// @returns true on error.
-      /// @brief Set the status information.
-      bool setStatusInfoOnDisk(const FileStatus &SI,
-                               std::string *ErrStr = 0) const;
-
-      /// 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, as needed. 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 true if the directory could not be created, false otherwise
-      /// @brief Create the directory this Path refers to.
-      bool createDirectoryOnDisk(
-        bool create_parents = false, ///<  Determines whether non-existent
-           ///< directory components other than the last one (the "parents")
-           ///< are created or not.
-        std::string* ErrMsg = 0 ///< Optional place to put error messages.
-      );
-
-      /// 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 createDirectoriesOnDisk to
-      /// accomplish that. The created file will be empty upon return from this
-      /// function.
-      /// @returns true if the file could not be created, false otherwise.
-      /// @brief Create the file this Path refers to.
-      bool createFileOnDisk(
-        std::string* ErrMsg = 0 ///< Optional place to put error messages.
-      );
-
-      /// This is like createFile except that it creates a temporary file. A
-      /// unique temporary file name is generated based on the contents of
-      /// \p this before the call. The new name is assigned to \p this and the
-      /// file is created.  Note that this will both change the Path object
-      /// *and* create the corresponding file. This function will ensure that
-      /// the newly generated temporary file name is unique in the file system.
-      /// @returns true if the file couldn't be created, false otherwise.
-      /// @brief Create a unique temporary file
-      bool createTemporaryFileOnDisk(
-        bool reuse_current = false, ///< When set to true, this parameter
-          ///< indicates that if the current file name does not exist then
-          ///< it will be used without modification.
-        std::string* ErrMsg = 0 ///< Optional place to put error messages
-      );
-
-      /// This method renames the file referenced by \p this as \p newName. The
-      /// file referenced by \p this must exist. The file referenced by
-      /// \p newName does not need to exist.
-      /// @returns true on error, false otherwise
-      /// @brief Rename one file as another.
-      bool renamePathOnDisk(const Path& newName, std::string* ErrMsg);
-
-      /// This method attempts to destroy the file or directory named by the
-      /// last component of the Path. If the Path refers to a directory and the
-      /// \p destroy_contents is false, an attempt will be made to remove just
-      /// the directory (the final Path component). If \p destroy_contents is
-      /// true, an attempt will be made to remove the entire contents of the
-      /// directory, recursively. If the Path refers to a file, the
-      /// \p destroy_contents parameter is ignored.
-      /// @param destroy_contents Indicates whether the contents of a destroyed
-      /// @param Err An optional string to receive an error message.
-      /// directory should also be destroyed (recursively).
-      /// @returns false if the file/directory was destroyed, true on error.
-      /// @brief Removes the file or directory from the filesystem.
-      bool eraseFromDisk(bool destroy_contents = false,
-                         std::string *Err = 0) const;
-
-
-      /// MapInFilePages - This is a low level system API to map in the file
-      /// that is currently opened as FD into the current processes' address
-      /// space for read only access.  This function may return null on failure
-      /// or if the system cannot provide the following constraints:
-      ///  1) The pages must be valid after the FD is closed, until
-      ///     UnMapFilePages is called.
-      ///  2) Any padding after the end of the file must be zero filled, if
-      ///     present.
-      ///  3) The pages must be contiguous.
-      ///
-      /// This API is not intended for general use, clients should use
-      /// MemoryBuffer::getFile instead.
-      static const char *MapInFilePages(int FD, uint64_t FileSize);
-
-      /// UnMapFilePages - Free pages mapped into the current process by
-      /// MapInFilePages.
-      ///
-      /// This API is not intended for general use, clients should use
-      /// MemoryBuffer::getFile instead.
-      static void UnMapFilePages(const char *Base, uint64_t FileSize);
-
-    /// @}
-    /// @name Data
-    /// @{
-    protected:
-      // Our win32 implementation relies on this string being mutable.
-      mutable std::string path;   ///< Storage for the path name.
-
-
-    /// @}
-  };
-
-  /// This class is identical to Path class except it allows you to obtain the
-  /// file status of the Path as well. The reason for the distinction is one of
-  /// efficiency. First, the file status requires additional space and the space
-  /// is incorporated directly into PathWithStatus without an additional malloc.
-  /// Second, obtaining status information is an expensive operation on most
-  /// operating systems so we want to be careful and explicity about where we
-  /// allow this operation in LLVM.
-  /// @brief Path with file status class.
-  class PathWithStatus : public Path {
-    /// @name Constructors
-    /// @{
-    public:
-      /// @brief Default constructor
-      PathWithStatus() : Path(), status(), fsIsValid(false) {}
-
-      /// @brief Copy constructor
-      PathWithStatus(const PathWithStatus &that)
-        : Path(static_cast<const Path&>(that)), status(that.status),
-           fsIsValid(that.fsIsValid) {}
-
-      /// This constructor allows construction from a Path object
-      /// @brief Path constructor
-      PathWithStatus(const Path &other)
-        : Path(other), status(), fsIsValid(false) {}
-
-      /// This constructor will accept a char* or std::string as a path. No
-      /// checking is done on this path to determine if it is valid. To
-      /// determine validity of the path, use the isValid method.
-      /// @brief Construct a Path from a string.
-      explicit PathWithStatus(
-        StringRef p ///< The path to assign.
-      ) : Path(p), status(), fsIsValid(false) {}
-
-      /// This constructor will accept a character range as a path.  No checking
-      /// is done on this path to determine if it is valid.  To determine
-      /// validity of the path, use the isValid method.
-      /// @brief Construct a Path from a string.
-      explicit PathWithStatus(
-        const char *StrStart,  ///< Pointer to the first character of the path
-        unsigned StrLen        ///< Length of the path.
-      ) : Path(StrStart, StrLen), status(), fsIsValid(false) {}
-
-      /// Makes a copy of \p that to \p this.
-      /// @returns \p this
-      /// @brief Assignment Operator
-      PathWithStatus &operator=(const PathWithStatus &that) {
-        static_cast<Path&>(*this) = static_cast<const Path&>(that);
-        status = that.status;
-        fsIsValid = that.fsIsValid;
-        return *this;
-      }
-
-      /// Makes a copy of \p that to \p this.
-      /// @returns \p this
-      /// @brief Assignment Operator
-      PathWithStatus &operator=(const Path &that) {
-        static_cast<Path&>(*this) = static_cast<const Path&>(that);
-        fsIsValid = false;
-        return *this;
-      }
-
-    /// @}
-    /// @name Methods
-    /// @{
-    public:
-      /// This function returns status information about the file. The type of
-      /// path (file or directory) is updated to reflect the actual contents
-      /// of the file system.
-      /// @returns 0 on failure, with Error explaining why (if non-zero)
-      /// @returns a pointer to a FileStatus structure on success.
-      /// @brief Get file status.
-      const FileStatus *getFileStatus(
-        bool forceUpdate = false, ///< Force an update from the file system
-        std::string *Error = 0    ///< Optional place to return an error msg.
-      ) const;
-
-    /// @}
-    /// @name Data
-    /// @{
-    private:
-      mutable FileStatus status; ///< Status information.
-      mutable bool fsIsValid;    ///< Whether we've obtained it or not
-
-    /// @}
-  };
-
-  /// This enumeration delineates the kinds of files that LLVM knows about.
-  enum LLVMFileType {
-    Unknown_FileType = 0,              ///< Unrecognized file
-    Bitcode_FileType,                  ///< Bitcode file
-    Archive_FileType,                  ///< ar style archive file
-    ELF_Relocatable_FileType,          ///< ELF Relocatable object file
-    ELF_Executable_FileType,           ///< ELF Executable image
-    ELF_SharedObject_FileType,         ///< ELF dynamically linked shared lib
-    ELF_Core_FileType,                 ///< ELF core image
-    Mach_O_Object_FileType,            ///< Mach-O Object file
-    Mach_O_Executable_FileType,        ///< Mach-O Executable
-    Mach_O_FixedVirtualMemorySharedLib_FileType, ///< Mach-O Shared Lib, FVM
-    Mach_O_Core_FileType,              ///< Mach-O Core File
-    Mach_O_PreloadExecutable_FileType, ///< Mach-O Preloaded Executable
-    Mach_O_DynamicallyLinkedSharedLib_FileType, ///< Mach-O dynlinked shared lib
-    Mach_O_DynamicLinker_FileType,     ///< The Mach-O dynamic linker
-    Mach_O_Bundle_FileType,            ///< Mach-O Bundle file
-    Mach_O_DynamicallyLinkedSharedLibStub_FileType, ///< Mach-O Shared lib stub
-    COFF_FileType                      ///< COFF object file or lib
-  };
-
-  /// This utility function allows any memory block to be examined in order
-  /// to determine its file type.
-  LLVMFileType IdentifyFileType(const char*magic, unsigned length);
-
-  /// This function can be used to copy the file specified by Src to the
-  /// file specified by Dest. If an error occurs, Dest is removed.
-  /// @returns true if an error occurs, false otherwise
-  /// @brief Copy one file to another.
-  bool CopyFile(const Path& Dest, const Path& Src, std::string* ErrMsg);
-
-  /// This is the OS-specific path separator: a colon on Unix or a semicolon
-  /// on Windows.
-  extern const char PathSeparator;
-}
-
-}
-
-#endif
+#include "llvm/Support/PathV1.h"
+#include "llvm/Support/PathV2.h"
diff --git a/include/llvm/Support/PathV1.h b/include/llvm/Support/PathV1.h
new file mode 100644
index 0000000..74215cb
--- /dev/null
+++ b/include/llvm/Support/PathV1.h
@@ -0,0 +1,733 @@
+//===- llvm/Support/PathV1.h - Path Operating System Concept ----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the llvm::sys::Path class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_PATH_H
+#define LLVM_SYSTEM_PATH_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/TimeValue.h"
+#include <set>
+#include <string>
+#include <vector>
+
+namespace llvm {
+namespace sys {
+
+  /// This structure provides basic file system information about a file. It
+  /// is patterned after the stat(2) Unix operating system call but made
+  /// platform independent and eliminates many of the unix-specific fields.
+  /// However, to support llvm-ar, the mode, user, and group fields are
+  /// retained. These pertain to unix security and may not have a meaningful
+  /// value on non-Unix platforms. However, the other fields should
+  /// always be applicable on all platforms.  The structure is filled in by
+  /// the PathWithStatus class.
+  /// @brief File status structure
+  class FileStatus {
+  public:
+    uint64_t    fileSize;   ///< Size of the file in bytes
+    TimeValue   modTime;    ///< Time of file's modification
+    uint32_t    mode;       ///< Mode of the file, if applicable
+    uint32_t    user;       ///< User ID of owner, if applicable
+    uint32_t    group;      ///< Group ID of owner, if applicable
+    uint64_t    uniqueID;   ///< A number to uniquely ID this file
+    bool        isDir  : 1; ///< True if this is a directory.
+    bool        isFile : 1; ///< True if this is a file.
+
+    FileStatus() : fileSize(0), modTime(0,0), mode(0777), user(999),
+                   group(999), uniqueID(0), isDir(false), isFile(false) { }
+
+    TimeValue getTimestamp() const { return modTime; }
+    uint64_t getSize() const { return fileSize; }
+    uint32_t getMode() const { return mode; }
+    uint32_t getUser() const { return user; }
+    uint32_t getGroup() const { return group; }
+    uint64_t getUniqueID() const { return uniqueID; }
+  };
+
+  /// 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. The class is patterned after the java.io.File class with various
+  /// extensions and several omissions (not relevant to LLVM).  A Path object
+  /// ensures that the path it encapsulates is syntactically valid for the
+  /// operating system it is running on but does not ensure correctness for
+  /// any particular file system. That is, a syntactically valid path might
+  /// specify path components that do not exist in the file system and using
+  /// such a Path to act on the file system could produce errors. There is one
+  /// invalid Path value which is permitted: the empty path.  The class should
+  /// never allow a syntactically invalid non-empty path name to be assigned.
+  /// Empty paths are required in order to indicate an error result in some
+  /// situations. If the path is empty, the isValid operation will return
+  /// false. All operations will fail if isValid 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. The methods are
+  /// grouped into four basic categories: Path Accessors (provide information
+  /// about the path without accessing disk), Disk Accessors (provide
+  /// information about the underlying file or directory), Path Mutators
+  /// (change the path information, not the disk), and Disk Mutators (change
+  /// the disk file/directory referenced by the path). The Disk Mutator methods
+  /// all have the word "disk" embedded in their method name to reinforce the
+  /// notion that the operation modifies the file system.
+  /// @since 1.4
+  /// @brief An abstraction for operating system paths.
+  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 file:///. Other operating systems may have different notions of
+      /// what the root directory is or none at all. In that case, a consistent
+      /// default root directory will be used.
+      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.
+      /// @returns an invalid path (empty) on error
+      /// @param ErrMsg Optional place for an error message if an error occurs
+      /// @brief Constrct a path to an new, unique, existing temporary
+      /// directory.
+      static Path GetTemporaryDirectory(std::string* ErrMsg = 0);
+
+      /// Construct a vector of sys::Path that contains the "standard" system
+      /// library paths suitable for linking into programs.
+      /// @brief Construct a path to the system library directory
+      static void GetSystemLibraryPaths(std::vector<sys::Path>& Paths);
+
+      /// Construct a vector of sys::Path that contains the "standard" bitcode
+      /// library paths suitable for linking into an llvm program. This function
+      /// *must* return the value of LLVM_LIB_SEARCH_PATH as well as the value
+      /// of LLVM_LIBDIR. It also must provide the System library paths as
+      /// returned by GetSystemLibraryPaths.
+      /// @see GetSystemLibraryPaths
+      /// @brief Construct a list of directories in which bitcode could be
+      /// found.
+      static void GetBitcodeLibraryPaths(std::vector<sys::Path>& Paths);
+
+      /// Find the path to a library using its short name. Use the system
+      /// dependent library paths to locate the library.
+      /// @brief Find a library.
+      static Path FindLibrary(std::string& short_name);
+
+      /// 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.
+      /// @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.
+      /// @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.
+      /// @brief Construct a path to the current user's "home" directory
+      static Path GetUserHomeDirectory();
+
+      /// Construct a path to the current directory for the current process.
+      /// @returns The current working directory.
+      /// @brief Returns the current working directory.
+      static Path GetCurrentDirectory();
+
+      /// Return the suffix commonly used on file names that contain an
+      /// executable.
+      /// @returns The executable file suffix for the current platform.
+      /// @brief Return the executable file suffix.
+      static StringRef GetEXESuffix();
+
+      /// Return the suffix commonly used on file names that contain a shared
+      /// object, shared archive, or dynamic link library. Such files are
+      /// linked at runtime into a process and their code images are shared
+      /// between processes.
+      /// @returns The dynamic link library suffix for the current platform.
+      /// @brief Return the dynamic link library suffix.
+      static StringRef GetDLLSuffix();
+
+      /// GetMainExecutable - Return the path to the main executable, given the
+      /// value of argv[0] from program startup and the address of main itself.
+      /// In extremis, this function may fail and return an empty path.
+      static Path GetMainExecutable(const char *argv0, void *MainAddr);
+
+      /// 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.
+      /// @brief Construct an empty (and invalid) path.
+      Path() : path() {}
+      Path(const Path &that) : path(that.path) {}
+
+      /// This constructor will accept a char* or std::string as a path. No
+      /// checking is done on this path to determine if it is valid. To
+      /// determine validity of the path, use the isValid method.
+      /// @param p The path to assign.
+      /// @brief Construct a Path from a string.
+      explicit Path(StringRef p);
+
+      /// This constructor will accept a character range as a path.  No checking
+      /// is done on this path to determine if it is valid.  To determine
+      /// validity of the path, use the isValid method.
+      /// @param StrStart A pointer to the first character of the path name
+      /// @param StrLen The length of the path name at StrStart
+      /// @brief Construct a Path from a string.
+      Path(const char *StrStart, unsigned StrLen);
+
+    /// @}
+    /// @name Operators
+    /// @{
+    public:
+      /// Makes a copy of \p that to \p this.
+      /// @returns \p this
+      /// @brief Assignment Operator
+      Path &operator=(const Path &that) {
+        path = that.path;
+        return *this;
+      }
+
+      /// Makes a copy of \p that to \p this.
+      /// @param that A StringRef denoting the path
+      /// @returns \p this
+      /// @brief Assignment Operator
+      Path &operator=(StringRef that);
+
+      /// Compares \p this Path with \p that Path for equality.
+      /// @returns true if \p this and \p that refer to the same thing.
+      /// @brief Equality Operator
+      bool operator==(const Path &that) const;
+
+      /// Compares \p this Path with \p that Path for inequality.
+      /// @returns true if \p this and \p that refer to different things.
+      /// @brief Inequality Operator
+      bool operator!=(const Path &that) const { return !(*this == that); }
+
+      /// 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.
+      /// @brief Less Than Operator
+      bool operator<(const Path& that) const;
+
+    /// @}
+    /// @name Path 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 isValid() const;
+
+      /// This function determines if the contents of the path name are empty.
+      /// That is, the path name has a zero length. This does NOT determine if
+      /// if the file is empty. To get the length of the file itself, Use the
+      /// PathWithStatus::getFileStatus() method and then the getSize() method
+      /// on the returned FileStatus object.
+      /// @returns true iff the path is empty.
+      /// @brief Determines if the path name is empty (invalid).
+      bool isEmpty() const { return path.empty(); }
+
+       /// This function returns the last component of the path name. The last
+      /// component is the file or directory name occuring after the last
+      /// directory separator. If no directory separator is present, the entire
+      /// path name is returned (i.e. same as toString).
+      /// @returns StringRef containing the last component of the path name.
+      /// @brief Returns the last component of the path name.
+      StringRef getLast() const;
+
+      /// This function strips off the path and suffix of the file or directory
+      /// name and returns just the basename. For example /a/foo.bar would cause
+      /// this function to return "foo".
+      /// @returns StringRef containing the basename of the path
+      /// @brief Get the base name of the path
+      StringRef getBasename() const;
+
+      /// This function strips off the suffix of the path beginning with the
+      /// path separator ('/' on Unix, '\' on Windows) and returns the result.
+      StringRef getDirname() const;
+
+      /// This function strips off the path and basename(up to and
+      /// including the last dot) of the file or directory name and
+      /// returns just the suffix. For example /a/foo.bar would cause
+      /// this function to return "bar".
+      /// @returns StringRef containing the suffix of the path
+      /// @brief Get the suffix of the path
+      StringRef getSuffix() const;
+
+      /// Obtain a 'C' string for the path name.
+      /// @returns a 'C' string containing the path name.
+      /// @brief Returns the path as a C string.
+      const char *c_str() const { return path.c_str(); }
+      const std::string &str() const { return path; }
+
+
+      /// size - Return the length in bytes of this path name.
+      size_t size() const { return path.size(); }
+
+      /// empty - Returns true if the path is empty.
+      unsigned empty() const { return path.empty(); }
+
+    /// @}
+    /// @name Disk Accessors
+    /// @{
+    public:
+      /// This function determines if the path name is absolute, as opposed to
+      /// relative.
+      /// @brief Determine if the path is absolute.
+      bool isAbsolute() const;
+
+      /// This function determines if the path name is absolute, as opposed to
+      /// relative.
+      /// @brief Determine if the path is absolute.
+      static bool isAbsolute(const char *NameStart, unsigned NameLen);
+
+      /// This function opens the file associated with the path name provided by
+      /// the Path object and reads its magic number. If the magic number at the
+      /// start of the file matches \p magic, true is returned. In all other
+      /// cases (file not found, file not accessible, etc.) it returns false.
+      /// @returns true if the magic number of the file matches \p magic.
+      /// @brief Determine if file has a specific magic number
+      bool hasMagicNumber(StringRef magic) const;
+
+      /// This function retrieves the first \p len bytes of the file associated
+      /// with \p this. These bytes are returned as the "magic number" in the
+      /// \p Magic parameter.
+      /// @returns true if the Path is a file and the magic number is retrieved,
+      /// false otherwise.
+      /// @brief Get the file's magic number.
+      bool getMagicNumber(std::string& Magic, unsigned len) const;
+
+      /// This function determines if the path name in the object references an
+      /// archive file by looking at its magic number.
+      /// @returns true if the file starts with the magic number for an archive
+      /// file.
+      /// @brief Determine if the path references an archive file.
+      bool isArchive() const;
+
+      /// This function determines if the path name in the object references an
+      /// LLVM Bitcode file by looking at its magic number.
+      /// @returns true if the file starts with the magic number for LLVM
+      /// bitcode files.
+      /// @brief Determine if the path references a bitcode file.
+      bool isBitcodeFile() const;
+
+      /// This function determines if the path name in the object references a
+      /// native Dynamic Library (shared library, shared object) by looking at
+      /// the file's magic number. The Path object must reference a file, not a
+      /// directory.
+      /// @returns true if the file starts with the magic number for a native
+      /// shared library.
+      /// @brief Determine if the path references a dynamic library.
+      bool isDynamicLibrary() const;
+
+      /// This function determines if the path name in the object references a
+      /// native object file by looking at it's magic number. The term object
+      /// file is defined as "an organized collection of separate, named
+      /// sequences of binary data." This covers the obvious file formats such
+      /// as COFF and ELF, but it also includes llvm ir bitcode, archives,
+      /// libraries, etc...
+      /// @returns true if the file starts with the magic number for an object
+      /// file.
+      /// @brief Determine if the path references an object file.
+      bool isObjectFile() const;
+
+      /// This function determines if the path name references an existing file
+      /// or directory in the file system.
+      /// @returns true if the pathname references an existing file or
+      /// directory.
+      /// @brief Determines if the path is a file or directory in
+      /// the file system.
+      bool exists() const;
+
+      /// This function determines if the path name references an
+      /// existing directory.
+      /// @returns true if the pathname references an existing directory.
+      /// @brief Determines if the path is a directory in the file system.
+      bool isDirectory() const;
+
+      /// This function determines if the path name references an
+      /// existing symbolic link.
+      /// @returns true if the pathname references an existing symlink.
+      /// @brief Determines if the path is a symlink in the file system.
+      bool isSymLink() const;
+
+      /// This function determines if the path name references a readable file
+      /// or directory in the file system. This function 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 canRead() const;
+
+      /// This function determines if the path name references a writable file
+      /// or directory in the file system. This function 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 canWrite() const;
+
+      /// This function checks that what we're trying to work only on a regular
+      /// file. Check for things like /dev/null, any block special file, or
+      /// other things that aren't "regular" regular files.
+      /// @returns true if the file is S_ISREG.
+      /// @brief Determines if the file is a regular file
+      bool isRegularFile() const;
+
+      /// This function determines if the path name references an executable
+      /// file in the file system. This function 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 canExecute() const;
+
+      /// This function builds a list of paths that are the names of the
+      /// files and directories in a directory.
+      /// @returns true if an error occurs, true otherwise
+      /// @brief Build a list of directory's contents.
+      bool getDirectoryContents(
+        std::set<Path> &paths, ///< The resulting list of file & directory names
+        std::string* ErrMsg    ///< Optional place to return an error message.
+      ) const;
+
+    /// @}
+    /// @name Path 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.
+      /// @brief Make the path empty.
+      void clear() { path.clear(); }
+
+      /// This method sets the Path object to \p unverified_path. This can fail
+      /// if the \p unverified_path does not pass the syntactic checks of the
+      /// isValid() method. If verification fails, the Path object remains
+      /// unchanged and false is returned. Otherwise true is returned and the
+      /// Path object takes on the path value of \p unverified_path
+      /// @returns true if the path was set, false otherwise.
+      /// @param unverified_path The path to be set in Path object.
+      /// @brief Set a full path from a StringRef
+      bool set(StringRef unverified_path);
+
+      /// One path component is removed from the Path. If only one component is
+      /// present in the path, the Path object becomes empty. If the Path object
+      /// is empty, no change is made.
+      /// @returns false if the path component could not be removed.
+      /// @brief Removes the last directory component of the Path.
+      bool eraseComponent();
+
+      /// The \p component is added to the end of the Path if it is a legal
+      /// name for the operating system. A directory separator will be added if
+      /// needed.
+      /// @returns false if the path component could not be added.
+      /// @brief Appends one path component to the Path.
+      bool appendComponent(StringRef component);
+
+      /// A period and the \p suffix are appended to the end of the pathname.
+      /// When the \p suffix is empty, no action is performed.
+      /// @brief Adds a period and the \p suffix to the end of the pathname.
+      void appendSuffix(StringRef suffix);
+
+      /// The suffix of the filename is erased. 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
+      /// returns false.
+      /// @returns false if there was no suffix to remove, true otherwise.
+      /// @brief Remove the suffix from a path name.
+      bool eraseSuffix();
+
+      /// The current Path name is made unique in the file system. Upon return,
+      /// the Path will have been changed to make a unique file in the file
+      /// system or it will not have been changed if the current path name is
+      /// already unique.
+      /// @throws std::string if an unrecoverable error occurs.
+      /// @brief Make the current path name unique in the file system.
+      bool makeUnique( bool reuse_current /*= true*/, std::string* ErrMsg );
+
+      /// The current Path name is made absolute by prepending the
+      /// current working directory if necessary.
+      void makeAbsolute();
+
+    /// @}
+    /// @name Disk Mutators
+    /// @{
+    public:
+      /// This method attempts to make the file referenced by the Path object
+      /// available for reading so that the canRead() method will return true.
+      /// @brief Make the file readable;
+      bool makeReadableOnDisk(std::string* ErrMsg = 0);
+
+      /// This method attempts to make the file referenced by the Path object
+      /// available for writing so that the canWrite() method will return true.
+      /// @brief Make the file writable;
+      bool makeWriteableOnDisk(std::string* ErrMsg = 0);
+
+      /// This method attempts to make the file referenced by the Path object
+      /// available for execution so that the canExecute() method will return
+      /// true.
+      /// @brief Make the file readable;
+      bool makeExecutableOnDisk(std::string* ErrMsg = 0);
+
+      /// This method allows the last modified time stamp and permission bits
+      /// to be set on the disk object referenced by the Path.
+      /// @throws std::string if an error occurs.
+      /// @returns true on error.
+      /// @brief Set the status information.
+      bool setStatusInfoOnDisk(const FileStatus &SI,
+                               std::string *ErrStr = 0) const;
+
+      /// 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, as needed. 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 true if the directory could not be created, false otherwise
+      /// @brief Create the directory this Path refers to.
+      bool createDirectoryOnDisk(
+        bool create_parents = false, ///<  Determines whether non-existent
+           ///< directory components other than the last one (the "parents")
+           ///< are created or not.
+        std::string* ErrMsg = 0 ///< Optional place to put error messages.
+      );
+
+      /// 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 createDirectoriesOnDisk to
+      /// accomplish that. The created file will be empty upon return from this
+      /// function.
+      /// @returns true if the file could not be created, false otherwise.
+      /// @brief Create the file this Path refers to.
+      bool createFileOnDisk(
+        std::string* ErrMsg = 0 ///< Optional place to put error messages.
+      );
+
+      /// This is like createFile except that it creates a temporary file. A
+      /// unique temporary file name is generated based on the contents of
+      /// \p this before the call. The new name is assigned to \p this and the
+      /// file is created.  Note that this will both change the Path object
+      /// *and* create the corresponding file. This function will ensure that
+      /// the newly generated temporary file name is unique in the file system.
+      /// @returns true if the file couldn't be created, false otherwise.
+      /// @brief Create a unique temporary file
+      bool createTemporaryFileOnDisk(
+        bool reuse_current = false, ///< When set to true, this parameter
+          ///< indicates that if the current file name does not exist then
+          ///< it will be used without modification.
+        std::string* ErrMsg = 0 ///< Optional place to put error messages
+      );
+
+      /// This method renames the file referenced by \p this as \p newName. The
+      /// file referenced by \p this must exist. The file referenced by
+      /// \p newName does not need to exist.
+      /// @returns true on error, false otherwise
+      /// @brief Rename one file as another.
+      bool renamePathOnDisk(const Path& newName, std::string* ErrMsg);
+
+      /// This method attempts to destroy the file or directory named by the
+      /// last component of the Path. If the Path refers to a directory and the
+      /// \p destroy_contents is false, an attempt will be made to remove just
+      /// the directory (the final Path component). If \p destroy_contents is
+      /// true, an attempt will be made to remove the entire contents of the
+      /// directory, recursively. If the Path refers to a file, the
+      /// \p destroy_contents parameter is ignored.
+      /// @param destroy_contents Indicates whether the contents of a destroyed
+      /// @param Err An optional string to receive an error message.
+      /// directory should also be destroyed (recursively).
+      /// @returns false if the file/directory was destroyed, true on error.
+      /// @brief Removes the file or directory from the filesystem.
+      bool eraseFromDisk(bool destroy_contents = false,
+                         std::string *Err = 0) const;
+
+
+      /// MapInFilePages - This is a low level system API to map in the file
+      /// that is currently opened as FD into the current processes' address
+      /// space for read only access.  This function may return null on failure
+      /// or if the system cannot provide the following constraints:
+      ///  1) The pages must be valid after the FD is closed, until
+      ///     UnMapFilePages is called.
+      ///  2) Any padding after the end of the file must be zero filled, if
+      ///     present.
+      ///  3) The pages must be contiguous.
+      ///
+      /// This API is not intended for general use, clients should use
+      /// MemoryBuffer::getFile instead.
+      static const char *MapInFilePages(int FD, uint64_t FileSize);
+
+      /// UnMapFilePages - Free pages mapped into the current process by
+      /// MapInFilePages.
+      ///
+      /// This API is not intended for general use, clients should use
+      /// MemoryBuffer::getFile instead.
+      static void UnMapFilePages(const char *Base, uint64_t FileSize);
+
+    /// @}
+    /// @name Data
+    /// @{
+    protected:
+      // Our win32 implementation relies on this string being mutable.
+      mutable std::string path;   ///< Storage for the path name.
+
+
+    /// @}
+  };
+
+  /// This class is identical to Path class except it allows you to obtain the
+  /// file status of the Path as well. The reason for the distinction is one of
+  /// efficiency. First, the file status requires additional space and the space
+  /// is incorporated directly into PathWithStatus without an additional malloc.
+  /// Second, obtaining status information is an expensive operation on most
+  /// operating systems so we want to be careful and explicity about where we
+  /// allow this operation in LLVM.
+  /// @brief Path with file status class.
+  class PathWithStatus : public Path {
+    /// @name Constructors
+    /// @{
+    public:
+      /// @brief Default constructor
+      PathWithStatus() : Path(), status(), fsIsValid(false) {}
+
+      /// @brief Copy constructor
+      PathWithStatus(const PathWithStatus &that)
+        : Path(static_cast<const Path&>(that)), status(that.status),
+           fsIsValid(that.fsIsValid) {}
+
+      /// This constructor allows construction from a Path object
+      /// @brief Path constructor
+      PathWithStatus(const Path &other)
+        : Path(other), status(), fsIsValid(false) {}
+
+      /// This constructor will accept a char* or std::string as a path. No
+      /// checking is done on this path to determine if it is valid. To
+      /// determine validity of the path, use the isValid method.
+      /// @brief Construct a Path from a string.
+      explicit PathWithStatus(
+        StringRef p ///< The path to assign.
+      ) : Path(p), status(), fsIsValid(false) {}
+
+      /// This constructor will accept a character range as a path.  No checking
+      /// is done on this path to determine if it is valid.  To determine
+      /// validity of the path, use the isValid method.
+      /// @brief Construct a Path from a string.
+      explicit PathWithStatus(
+        const char *StrStart,  ///< Pointer to the first character of the path
+        unsigned StrLen        ///< Length of the path.
+      ) : Path(StrStart, StrLen), status(), fsIsValid(false) {}
+
+      /// Makes a copy of \p that to \p this.
+      /// @returns \p this
+      /// @brief Assignment Operator
+      PathWithStatus &operator=(const PathWithStatus &that) {
+        static_cast<Path&>(*this) = static_cast<const Path&>(that);
+        status = that.status;
+        fsIsValid = that.fsIsValid;
+        return *this;
+      }
+
+      /// Makes a copy of \p that to \p this.
+      /// @returns \p this
+      /// @brief Assignment Operator
+      PathWithStatus &operator=(const Path &that) {
+        static_cast<Path&>(*this) = static_cast<const Path&>(that);
+        fsIsValid = false;
+        return *this;
+      }
+
+    /// @}
+    /// @name Methods
+    /// @{
+    public:
+      /// This function returns status information about the file. The type of
+      /// path (file or directory) is updated to reflect the actual contents
+      /// of the file system.
+      /// @returns 0 on failure, with Error explaining why (if non-zero)
+      /// @returns a pointer to a FileStatus structure on success.
+      /// @brief Get file status.
+      const FileStatus *getFileStatus(
+        bool forceUpdate = false, ///< Force an update from the file system
+        std::string *Error = 0    ///< Optional place to return an error msg.
+      ) const;
+
+    /// @}
+    /// @name Data
+    /// @{
+    private:
+      mutable FileStatus status; ///< Status information.
+      mutable bool fsIsValid;    ///< Whether we've obtained it or not
+
+    /// @}
+  };
+
+  /// This enumeration delineates the kinds of files that LLVM knows about.
+  enum LLVMFileType {
+    Unknown_FileType = 0,              ///< Unrecognized file
+    Bitcode_FileType,                  ///< Bitcode file
+    Archive_FileType,                  ///< ar style archive file
+    ELF_Relocatable_FileType,          ///< ELF Relocatable object file
+    ELF_Executable_FileType,           ///< ELF Executable image
+    ELF_SharedObject_FileType,         ///< ELF dynamically linked shared lib
+    ELF_Core_FileType,                 ///< ELF core image
+    Mach_O_Object_FileType,            ///< Mach-O Object file
+    Mach_O_Executable_FileType,        ///< Mach-O Executable
+    Mach_O_FixedVirtualMemorySharedLib_FileType, ///< Mach-O Shared Lib, FVM
+    Mach_O_Core_FileType,              ///< Mach-O Core File
+    Mach_O_PreloadExecutable_FileType, ///< Mach-O Preloaded Executable
+    Mach_O_DynamicallyLinkedSharedLib_FileType, ///< Mach-O dynlinked shared lib
+    Mach_O_DynamicLinker_FileType,     ///< The Mach-O dynamic linker
+    Mach_O_Bundle_FileType,            ///< Mach-O Bundle file
+    Mach_O_DynamicallyLinkedSharedLibStub_FileType, ///< Mach-O Shared lib stub
+    COFF_FileType                      ///< COFF object file or lib
+  };
+
+  /// This utility function allows any memory block to be examined in order
+  /// to determine its file type.
+  LLVMFileType IdentifyFileType(const char*magic, unsigned length);
+
+  /// This function can be used to copy the file specified by Src to the
+  /// file specified by Dest. If an error occurs, Dest is removed.
+  /// @returns true if an error occurs, false otherwise
+  /// @brief Copy one file to another.
+  bool CopyFile(const Path& Dest, const Path& Src, std::string* ErrMsg);
+
+  /// This is the OS-specific path separator: a colon on Unix or a semicolon
+  /// on Windows.
+  extern const char PathSeparator;
+}
+
+}
+
+#endif