llvm-6502/include/llvm/System/Path.h
Chris Lattner ff74ac103d #include <iosfwd> not <ostream>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29061 91177308-0d34-0410-b5e6-96231b3b80d8
2006-07-07 18:10:59 +00:00

575 lines
28 KiB
C++

//===- llvm/System/Path.h - Path Operating System Concept -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and 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/System/TimeValue.h"
#include <set>
#include <string>
#include <vector>
#include <iosfwd>
namespace llvm {
namespace sys {
/// 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 Types
/// @{
public:
/// 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 fileSize and modTime fields
/// should always be applicabe on all platforms. The structure is
/// filled in by the getStatusInfo method.
/// @brief File status structure
struct StatusInfo {
StatusInfo() : fileSize(0), modTime(0,0), mode(0777), user(999),
group(999), isDir(false) { }
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
bool isDir; ///< True if this is a directory.
};
/// @}
/// @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 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.
/// @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 vector of sys::Path that contains the "standard" system
/// library paths suitable for linking into programs. This function *must*
/// return the value of LLVM_LIB_SEARCH_PATH as the first item in \p Paths
/// if that environment variable is set and it references a directory.
/// @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" bytecode
/// 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 bytecode could be
/// found.
static void GetBytecodeLibraryPaths(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();
/// 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 std::string GetDLLSuffix();
/// 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() {}
/// This constructor will accept a std::string as a path but it 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 \p unverified_path is not legal.
/// @param unverified_path The path to verify and assign.
/// @brief Construct a Path from a string.
explicit Path(const std::string& unverified_path);
/// @}
/// @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;
}
/// 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 {
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.
/// @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.
/// @brief Less Than Operator
bool operator< (const Path& that) const {
return 0 > path.compare( that.path );
}
/// @}
/// @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 has a zero length. This does NOT determine if
/// if the file is empty. Use the getSize method for that.
/// @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 current contents of the path as a
/// std::string. This allows the underlying path string to be manipulated.
/// @returns std::string containing the path name.
/// @brief Returns the path as a std::string.
const std::string& toString() const { return path; }
/// 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 std::string containing the last component of the path name.
/// @brief Returns the last component of the path name.
std::string 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 std::string containing the basename of the path
/// @brief Get the base name of the path
std::string getBasename() 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* const c_str() const { return path.c_str(); }
/// @}
/// @name Disk Accessors
/// @{
public:
/// This function determines if the object referenced by this path is
/// a file or not. This function accesses the underlying file system to
/// determine the type of entity referenced by the path.
/// @returns true if this path name references a file.
/// @brief Determines if the path name references a file.
bool isFile() const;
/// This function determines if the object referenced by this path is a
/// directory or not. This function accesses the underlying file system to
/// determine the type of entity referenced by the path.
/// @returns true if the path name references a directory
/// @brief Determines if the path name references a directory.
bool isDirectory() const;
/// This function determines if the path refers to a hidden file. The
/// notion of hidden files is defined by the underlying system. The
/// system may not support hidden files in which case this function always
/// returns false on such systems. Hidden files have the "hidden"
/// attribute set on Win32. On Unix, hidden files start with a period.
/// @brief Determines if the path name references a hidden file.
bool isHidden() 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 isRootDirectory() const;
/// 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(const std::string& 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 Bytecode file by looking at its magic number.
/// @returns true if the file starts with the magic number for LLVM
/// bytecode files.
/// @brief Determine if the path references a bytecode file.
bool isBytecodeFile() 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.
/// @return strue if the file starts with the magid number for a native
/// shared library.
/// @brief Determine if the path reference a dynamic library.
bool isDynamicLibrary() 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 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 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 false if \p this is not a directory, true otherwise
/// @throws std::string if the directory cannot be searched
/// @brief Build a list of directory's contents.
bool getDirectoryContents(std::set<Path>& paths) const;
/// 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. If the file does not exist, false is returned.
/// For other (hard I/O) errors, a std::string is thrown indicating the
/// problem.
/// @throws std::string if an error occurs.
/// @brief Get file status.
void getStatusInfo(StatusInfo& info) const;
/// This function returns the last modified time stamp for the file
/// referenced by this path. The Path may reference a file or a directory.
/// If the file does not exist, a ZeroTime timestamp is returned.
/// @returns last modified timestamp of the file/directory or ZeroTime
/// @brief Get file timestamp.
inline TimeValue getTimestamp() const {
StatusInfo info; getStatusInfo(info); return info.modTime;
}
/// This function returns the size of the file referenced by this path.
/// @brief Get file size.
inline size_t getSize() const {
StatusInfo info; getStatusInfo(info); return info.fileSize;
}
/// @}
/// @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 std::string
bool set(const std::string& 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( const std::string& component );
/// 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. isFile() 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.
/// @brief Adds a period and the \p suffix to the end of the pathname.
bool appendSuffix(const std::string& 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.
void makeUnique( bool reuse_current = true );
/// @}
/// @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;
void makeReadableOnDisk();
/// 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;
void makeWriteableOnDisk();
/// 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;
void makeExecutableOnDisk();
/// 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
/// @brief Set the status information.
bool setStatusInfoOnDisk(const StatusInfo& si) 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 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 createDirectoryOnDisk( 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 createDirectoriesOnDisk 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 createFileOnDisk();
/// 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.
/// @param reuse_current When set to true, this parameter indicates that
/// if the current file name does not exist then it will be used without
/// modification.
/// @returns true if successful, false if the file couldn't be created.
/// @throws std::string if there is a hard error creating the temp file
/// name.
/// @brief Create a unique temporary file
bool createTemporaryFileOnDisk(bool reuse_current = false);
/// 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
/// @throws std::string if there is an file system error.
/// @brief Rename one file as another.
bool renamePathOnDisk(const Path& newName);
/// 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
/// directory should also be destroyed (recursively).
/// @returns true if the file/directory was destroyed, false if the path
/// refers to something that is neither a file nor a directory.
/// @throws std::string if there is an error.
/// @brief Removes the file or directory from the filesystem.
bool eraseFromDisk( bool destroy_contents = false ) const;
/// @}
/// @name Data
/// @{
private:
mutable std::string path; ///< Storage for the path name.
/// @}
};
/// This enumeration delineates the kinds of files that LLVM knows about.
enum LLVMFileType {
UnknownFileType = 0, ///< Unrecognized file
BytecodeFileType = 1, ///< Uncompressed bytecode file
CompressedBytecodeFileType = 2, ///< Compressed bytecode file
ArchiveFileType = 3 ///< ar style archive file
};
/// 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.
/// @throws std::string if an error opening or writing the files occurs.
/// @brief Copy one file to another.
void CopyFile(const Path& Dest, const Path& Src);
}
std::ostream& operator<<(std::ostream& strm, const sys::Path& aPath);
}
#endif