llvm-6502/include/llvm/Support/FileSystem.h
Michael J. Spencer 628467ef1f Support/PathV2: Implement has_magic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122587 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-28 01:49:01 +00:00

680 lines
25 KiB
C++

//===- llvm/Support/FileSystem.h - File System OS 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::fs namespace. It is designed after
// TR2/boost filesystem (v3), but modified to remove exception handling and the
// path class.
//
// All functions return an error_code and their actual work via the last out
// argument. The out argument is defined if and only if errc::success is
// returned. A function may return any error code in the generic or system
// category. However, they shall be equivalent to any error conditions listed
// in each functions respective documentation if the condition applies. [ note:
// this does not guarantee that error_code will be in the set of explicitly
// listed codes, but it does guarantee that if any of the explicitly listed
// errors occur, the correct error_code will be used ]. All functions may
// return errc::not_enough_memory if there is not enough memory to complete the
// operation.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FILE_SYSTEM_H
#define LLVM_SUPPORT_FILE_SYSTEM_H
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/system_error.h"
#include <ctime>
#include <iterator>
#include <string>
namespace llvm {
namespace sys {
namespace fs {
/// file_type - An "enum class" enumeration for the file system's view of the
/// type.
struct file_type {
enum _ {
status_error,
file_not_found,
regular_file,
directory_file,
symlink_file,
block_file,
character_file,
fifo_file,
socket_file,
type_unknown
};
file_type(_ v) : v_(v) {}
explicit file_type(int v) : v_(_(v)) {}
operator int() const {return v_;}
private:
int v_;
};
/// copy_option - An "enum class" enumeration of copy semantics for copy
/// operations.
struct copy_option {
enum _ {
fail_if_exists,
overwrite_if_exists
};
copy_option(_ v) : v_(v) {}
explicit copy_option(int v) : v_(_(v)) {}
operator int() const {return v_;}
private:
int v_;
};
/// space_info - Self explanatory.
struct space_info {
uint64_t capacity;
uint64_t free;
uint64_t available;
};
/// file_status - Represents the result of a call to stat and friends. It has
/// a platform specific member to store the result.
class file_status
{
// implementation defined status field.
file_type Type;
public:
explicit file_status(file_type v=file_type::status_error)
: Type(v) {}
file_type type() const { return Type; }
void type(file_type v) { Type = v; }
};
/// @}
/// @name Physical Operators
/// @{
/// @brief Make \a path an absolute path.
///
/// Makes \a path absolute using the current directory if it is not already. An
/// empty \a path will result in the current directory.
///
/// /absolute/path => /absolute/path
/// relative/../path => <current-directory>/relative/../path
///
/// @param path A path that is modified to be an absolute path.
/// @returns errc::success if \a path has been made absolute, otherwise a
/// platform specific error_code.
error_code make_absolute(SmallVectorImpl<char> &path);
/// @brief Copy the file at \a from to the path \a to.
///
/// @param from The path to copy the file from.
/// @param to The path to copy the file to.
/// @param copt Behavior if \a to already exists.
/// @returns errc::success if the file has been successfully copied.
/// errc::file_exists if \a to already exists and \a copt ==
/// copy_option::fail_if_exists. Otherwise a platform specific
/// error_code.
error_code copy_file(const Twine &from, const Twine &to,
copy_option copt = copy_option::fail_if_exists);
/// @brief Create all the non-existent directories in path.
///
/// @param path Directories to create.
/// @param existed Set to true if \a path already existed, false otherwise.
/// @returns errc::success if is_directory(path) and existed have been set,
/// otherwise a platform specific error_code.
error_code create_directories(const Twine &path, bool &existed);
/// @brief Create the directory in path.
///
/// @param path Directory to create.
/// @param existed Set to true if \a path already existed, false otherwise.
/// @returns errc::success if is_directory(path) and existed have been set,
/// otherwise a platform specific error_code.
error_code create_directory(const Twine &path, bool &existed);
/// @brief Create a hard link from \a from to \a to.
///
/// @param to The path to hard link to.
/// @param from The path to hard link from. This is created.
/// @returns errc::success if exists(to) && exists(from) && equivalent(to, from)
/// , otherwise a platform specific error_code.
error_code create_hard_link(const Twine &to, const Twine &from);
/// @brief Create a symbolic link from \a from to \a to.
///
/// @param to The path to symbolically link to.
/// @param from The path to symbolically link from. This is created.
/// @returns errc::success if exists(to) && exists(from) && is_symlink(from),
/// otherwise a platform specific error_code.
error_code create_symlink(const Twine &to, const Twine &from);
/// @brief Get the current path.
///
/// @param result Holds the current path on return.
/// @results errc::success if the current path has been stored in result,
/// otherwise a platform specific error_code.
error_code current_path(SmallVectorImpl<char> &result);
/// @brief Remove path. Equivalent to POSIX remove().
///
/// @param path Input path.
/// @param existed Set to true if \a path existed, false if it did not.
/// undefined otherwise.
/// @results errc::success if path has been removed and existed has been
/// successfully set, otherwise a platform specific error_code.
error_code remove(const Twine &path, bool &existed);
/// @brief Recursively remove all files below \a path, then \a path. Files are
/// removed as if by POSIX remove().
///
/// @param path Input path.
/// @param num_removed Number of files removed.
/// @results errc::success if path has been removed and num_removed has been
/// successfully set, otherwise a platform specific error_code.
error_code remove_all(const Twine &path, uint32_t &num_removed);
/// @brief Rename \a from to \a to. Files are renamed as if by POSIX rename().
///
/// @param from The path to rename from.
/// @param to The path to rename to. This is created.
error_code rename(const Twine &from, const Twine &to);
/// @brief Resize path to size. File is resized as if by POSIX truncate().
///
/// @param path Input path.
/// @param size Size to resize to.
/// @returns errc::success if \a path has been resized to \a size, otherwise a
/// platform specific error_code.
error_code resize_file(const Twine &path, uint64_t size);
/// @brief Make file readable.
///
/// @param path Input path.
/// @param value If true, make readable, else, make unreadable.
/// @results errc::success if readability has been successfully set, otherwise a
/// platform specific error_code.
error_code set_read(const Twine &path, bool value);
/// @brief Make file writeable.
///
/// @param path Input path.
/// @param value If true, make writeable, else, make unwriteable.
/// @results errc::success if writeability has been successfully set, otherwise
/// a platform specific error_code.
error_code set_write(const Twine &path, bool value);
/// @brief Make file executable.
///
/// @param path Input path.
/// @param value If true, make executable, else, make unexecutable.
/// @results errc::success if executability has been successfully set, otherwise
/// a platform specific error_code.
error_code set_execute(const Twine &path, bool value);
/// @}
/// @name Physical Observers
/// @{
/// @brief Does file exist?
///
/// @param status A file_status previously returned from stat.
/// @results True if the file represented by status exists, false if it does
/// not.
bool exists(file_status status);
/// @brief Does file exist?
///
/// @param path Input path.
/// @param result Set to true if the file represented by status exists, false if
/// it does not. Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code exists(const Twine &path, bool &result);
/// @brief Do file_status's represent the same thing?
///
/// @param A Input file_status.
/// @param B Input file_status.
///
/// assert(status_known(A) || status_known(B));
///
/// @results True if A and B both represent the same file system entity, false
/// otherwise.
bool equivalent(file_status A, file_status B);
/// @brief Do paths represent the same thing?
///
/// @param A Input path A.
/// @param B Input path B.
/// @param result Set to true if stat(A) and stat(B) have the same device and
/// inode (or equivalent).
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code equivalent(const Twine &A, const Twine &B, bool &result);
/// @brief Get file size.
///
/// @param path Input path.
/// @param result Set to the size of the file in \a path.
/// @returns errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code file_size(const Twine &path, uint64_t &result);
/// @brief Does status represent a directory?
///
/// @param status A file_status previously returned from status.
/// @results status.type() == file_type::directory_file.
bool is_directory(file_status status);
/// @brief Is path a directory?
///
/// @param path Input path.
/// @param result Set to true if \a path is a directory, false if it is not.
/// Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_directory(const Twine &path, bool &result);
/// @brief Is path an empty file?
///
/// @param path Input path.
/// @param result Set to true if \a path is a an empty file, false if it is not.
/// Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_empty(const Twine &path, bool &result);
/// @brief Does status represent a regular file?
///
/// @param status A file_status previously returned from status.
/// @results status_known(status) && status.type() == file_type::regular_file.
bool is_regular_file(file_status status);
/// @brief Is path a regular file?
///
/// @param path Input path.
/// @param result Set to true if \a path is a regular file, false if it is not.
/// Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_regular_file(const Twine &path, bool &result);
/// @brief Does this status represent something that exists but is not a
/// directory, regular file, or symlink?
///
/// @param status A file_status previously returned from status.
/// @results exists(s) && !is_regular_file(s) && !is_directory(s) &&
/// !is_symlink(s)
bool is_other(file_status status);
/// @brief Is path something that exists but is not a directory,
/// regular file, or symlink?
///
/// @param path Input path.
/// @param result Set to true if \a path exists, but is not a directory, regular
/// file, or a symlink, false if it does not. Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_other(const Twine &path, bool &result);
/// @brief Does status represent a symlink?
///
/// @param status A file_status previously returned from stat.
/// @param result status.type() == symlink_file.
bool is_symlink(file_status status);
/// @brief Is path a symlink?
///
/// @param path Input path.
/// @param result Set to true if \a path is a symlink, false if it is not.
/// Undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_symlink(const Twine &path, bool &result);
/// @brief Get last write time without changing it.
///
/// @param path Input path.
/// @param result Set to the last write time (UNIX time) of \a path if it
/// exists.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code last_write_time(const Twine &path, std::time_t &result);
/// @brief Set last write time.
///
/// @param path Input path.
/// @param value Time to set (UNIX time) \a path's last write time to.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code set_last_write_time(const Twine &path, std::time_t value);
/// @brief Read a symlink's value.
///
/// @param path Input path.
/// @param result Set to the value of the symbolic link \a path.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code read_symlink(const Twine &path, SmallVectorImpl<char> &result);
/// @brief Get disk space usage information.
///
/// @param path Input path.
/// @param result Set to the capacity, free, and available space on the device
/// \a path is on.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code disk_space(const Twine &path, space_info &result);
/// @brief Get file status as if by POSIX stat().
///
/// @param path Input path.
/// @param result Set to the file status.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code status(const Twine &path, file_status &result);
/// @brief Is status available?
///
/// @param path Input path.
/// @results True if status() != status_error.
bool status_known(file_status s);
/// @brief Is status available?
///
/// @param path Input path.
/// @param result Set to true if status() != status_error.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code status_known(const Twine &path, bool &result);
/// @brief Get file status as if by POSIX lstat().
///
/// Does not resolve symlinks.
///
/// @param path Input path.
/// @param result Set to the file status.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code symlink_status(const Twine &path, file_status &result);
/// @brief Generate a unique path and open it as a file.
///
/// Generates a unique path suitable for a temporary file and then opens it as a
/// file. The name is based on \a model with '%' replaced by a random char in
/// [0-9a-f]. If \a model is not an absolute path, a suitable temporary
/// directory will be prepended.
///
/// This is an atomic operation. Either the file is created and opened, or the
/// file system is left untouched.
///
/// clang-%%-%%-%%-%%-%%.s => /tmp/clang-a0-b1-c2-d3-e4.s
///
/// @param model Name to base unique path off of.
/// @param result_fs Set to the opened file's file descriptor.
/// @param result_path Set to the opened file's absolute path.
/// @results errc::success if result_{fd,path} have been successfully set,
/// otherwise a platform specific error_code.
error_code unique_file(const Twine &model, int &result_fd,
SmallVectorImpl<char> &result_path);
/// @brief Canonicalize path.
///
/// Sets result to the file system's idea of what path is. The result is always
/// absolute and has the same capitalization as the file system.
///
/// @param path Input path.
/// @param result Set to the canonicalized version of \a path.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code canonicalize(const Twine &path, SmallVectorImpl<char> &result);
/// @brief Are \a path's first bytes \a magic?
///
/// @param path Input path.
/// @param magic Byte sequence to compare \a path's first len(magic) bytes to.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code has_magic(const Twine &path, const Twine &magic, bool &result);
/// @brief Get \a path's first \a len bytes.
///
/// @param path Input path.
/// @param len Number of magic bytes to get.
/// @param result Set to the first \a len bytes in the file pointed to by
/// \a path.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code get_magic(const Twine &path, uint32_t len,
SmallVectorImpl<char> &result);
/// @brief Is file bitcode?
///
/// @param path Input path.
/// @param result Set to true if \a path is a bitcode file, false if it is not,
/// undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_bitcode(const Twine &path, bool &result);
/// @brief Is file a dynamic library?
///
/// @param path Input path.
/// @param result Set to true if \a path is a dynamic library, false if it is
/// not, undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_dynamic_library(const Twine &path, bool &result);
/// @brief Is an object file?
///
/// @param path Input path.
/// @param result Set to true if \a path is an object file, false if it is not,
/// undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code is_object_file(const Twine &path, bool &result);
/// @brief Can file be read?
///
/// @param path Input path.
/// @param result Set to true if \a path is readable, false it it is not,
/// undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code can_read(const Twine &path, bool &result);
/// @brief Can file be written?
///
/// @param path Input path.
/// @param result Set to true if \a path is writeable, false it it is not,
/// undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code can_write(const Twine &path, bool &result);
/// @brief Can file be executed?
///
/// @param path Input path.
/// @param result Set to true if \a path is executable, false it it is not,
/// undefined otherwise.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code can_execute(const Twine &path, bool &result);
/// @brief Get library paths the system linker uses.
///
/// @param result Set to the list of system library paths.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code GetSystemLibraryPaths(SmallVectorImpl<std::string> &result);
/// @brief Get bitcode library paths the system linker uses
/// + LLVM_LIB_SEARCH_PATH + LLVM_LIBDIR.
///
/// @param result Set to the list of bitcode library paths.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code GetBitcodeLibraryPaths(SmallVectorImpl<std::string> &result);
/// @brief Find a library.
///
/// Find the path to a library using its short name. Use the system
/// dependent library paths to locate the library.
///
/// c => /usr/lib/libc.so
///
/// @param short_name Library name one would give to the system linker.
/// @param result Set to the absolute path \a short_name represents.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code FindLibrary(const Twine &short_name, SmallVectorImpl<char> &result);
/// @brief Get absolute path of main executable.
///
/// @param argv0 The program name as it was spelled on the command line.
/// @param MainAddr Address of some symbol in the executable (not in a library).
/// @param result Set to the absolute path of the current executable.
/// @results errc::success if result has been successfully set, otherwise a
/// platform specific error_code.
error_code GetMainExecutable(const char *argv0, void *MainAddr,
SmallVectorImpl<char> &result);
/// @}
/// @name Iterators
/// @{
/// directory_entry - A single entry in a directory. Caches the status either
/// from the result of the iteration syscall, or the first time status or
/// symlink_status is called.
class directory_entry {
std::string Path;
mutable file_status Status;
mutable file_status SymlinkStatus;
public:
explicit directory_entry(const Twine &path, file_status st = file_status(),
file_status symlink_st = file_status())
: Path(path.str())
, Status(st)
, SymlinkStatus(symlink_st) {}
directory_entry() {}
void assign(const Twine &path, file_status st = file_status(),
file_status symlink_st = file_status()) {
Path = path.str();
Status = st;
SymlinkStatus = symlink_st;
}
void replace_filename(const Twine &filename, file_status st = file_status(),
file_status symlink_st = file_status());
StringRef path() const { return Path; }
error_code status(file_status &result) const;
error_code symlink_status(file_status &result) const;
bool operator==(const directory_entry& rhs) const { return Path == rhs.Path; }
bool operator!=(const directory_entry& rhs) const { return !(*this == rhs); }
bool operator< (const directory_entry& rhs) const;
bool operator<=(const directory_entry& rhs) const;
bool operator> (const directory_entry& rhs) const;
bool operator>=(const directory_entry& rhs) const;
};
/// directory_iterator - Iterates through the entries in path. There is no
/// operator++ because we need an error_code. If it's really needed we can make
/// it call report_fatal_error on error.
class directory_iterator {
intptr_t IterationHandle;
directory_entry CurrentEntry;
// Platform implementations implement these functions to handle iteration.
friend error_code directory_iterator_construct(directory_iterator &it,
StringRef path);
friend error_code directory_iterator_increment(directory_iterator &it);
friend error_code directory_iterator_destruct(directory_iterator &it);
public:
explicit directory_iterator(const Twine &path, error_code &ec)
: IterationHandle(0) {
SmallString<128> path_storage;
ec = directory_iterator_construct(*this, path.toStringRef(path_storage));
}
/// Construct end iterator.
directory_iterator() : IterationHandle(0) {}
~directory_iterator() {
directory_iterator_destruct(*this);
}
// No operator++ because we need error_code.
directory_iterator &increment(error_code &ec) {
ec = directory_iterator_increment(*this);
return *this;
}
const directory_entry &operator*() const { return CurrentEntry; }
const directory_entry *operator->() const { return &CurrentEntry; }
bool operator!=(const directory_iterator &RHS) const {
return CurrentEntry != RHS.CurrentEntry;
}
// Other members as required by
// C++ Std, 24.1.1 Input iterators [input.iterators]
};
/// recursive_directory_iterator - Same as directory_iterator except for it
/// recurses down into child directories.
class recursive_directory_iterator {
uint16_t Level;
bool HasNoPushRequest;
// implementation directory iterator status
public:
explicit recursive_directory_iterator(const Twine &path, error_code &ec);
// No operator++ because we need error_code.
directory_iterator &increment(error_code &ec);
const directory_entry &operator*() const;
const directory_entry *operator->() const;
// observers
/// Gets the current level. path is at level 0.
int level() const;
/// Returns true if no_push has been called for this directory_entry.
bool no_push_request() const;
// modifiers
/// Goes up one level if Level > 0.
void pop();
/// Does not go down into the current directory_entry.
void no_push();
// Other members as required by
// C++ Std, 24.1.1 Input iterators [input.iterators]
};
/// @}
} // end namespace fs
} // end namespace sys
} // end namespace llvm
#endif